JP3731324B2 - How to prevent contamination of microwave oven door glass - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating cooker such as a microwave oven and a microwave oven, and more particularly to a method for preventing contamination of a door glass of a microwave oven in which the door glass is fixed with an adhesive such as a silicone putty.
[0002]
[Prior art]
Heating cookers such as microwave ovens and microwave ovens are provided with a window on the door so that the state of the food stored in the heating chamber can be seen, a punching hole is provided in the window, and tempered soda glass is provided. A structure bonded with a silicone putty is used. In microwave ovens and microwave ovens, metal door frames are used for doors for radio wave cooking, and the door frames are provided with punching metal to look inside and shield radio waves. There is a choke structure for shielding radio waves around it to shield the radio waves. This is because a high-frequency heating cooker such as a microwave oven or a microwave oven heats food by putting it in its heating cabinet, and therefore, glass that can withstand high temperatures and has strength is optimal. Further, a door frame made of a metal sheet metal product is used for the door for radio wave sealing, and many of them are painted. In order to fix the door frame and the glass, a silicone putty that has heat resistance and can absorb the difference in thermal expansion between the metal and the glass has been often used.
[0003]
[Problems to be solved by the invention]
However, the conventional microwave oven door glass is difficult to wipe off when oil or the like from food is stuck with heat or the like. In addition, the non-adhesive coating on the surface of the glass means that dirt is removed as disclosed in JP-A-4-243934 “Water and oil repellent glass for cooking utensils and its manufacturing method”. It has the effect of becoming easy. However, when a water- and oil-repellent coating is applied to the surface of the door glass, the door glass and the door frame are not bonded when the coating is applied to the silicone putty part that bonds the glass and the door frame. In addition, there is a problem that the door glass is clouded by steam or detergent entering between the door glass and the silicone putty. As described above, it is difficult to wipe off steam, detergent, and the like that have entered from the gap between the door glass and the silicone putty.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention forms a film having a fluoroalkyl group and a siloxane bond on the surface of a door glass, and after removing the film formed on the end surface of the door glass by corona discharge treatment, The end face of the door glass and the door frame are bonded with an adhesive such as a silicone putty. And it can be set as the door glass which does not permeate from the interface of an adhesive body and glass, and the adhesion of an adhesive body and the glass surface ensuring the adhesion of the stain | pollution | contamination is hard to adhere.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention , the film is removed by corona discharge. Further, the removal was performed by corona discharge treatment, and the corona discharge treatment was performed at an angle with respect to the end surface of the door glass at the time of the removal, and the removal amount was adjusted to remove the film.
[0006]
And by the said structure, it can be set as the door glass which does not permeate | penetrate from the interface of a putty and glass, and the adhesion of the putty and the glass surface is ensured, and it is hard to stick to dirt.
[0007]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0008]
FIG. 1 is an enlarged view of a main part of a door portion of a microwave oven according to Embodiment 1 of the present invention.
[0009]
FIG. 2 is a schematic diagram of the corona discharge treatment for the door glass 1.
[0010]
The door glass 1 is provided with a film 2, and the film 2 is obtained by removing the film removing portion 6 by corona discharge treatment, and then applying a silicone putty between the door frame 4 and the door glass 1 and heat-curing the bonded body. 3 is bonded to the door frame 4 having the punching hole 5. The application range of the silicone putty is sufficient at the portion from which the film is removed, but it is not limited to this range in production, and it may be applied in a form including a part of the film. Moreover, this punching hole 5 is obtained by integral molding with a manufacturing top frame, and in the present invention, this punching hole may not be provided.
[0011]
The film 2 is configured to have a fluoroalkyl group and a siloxane bond, and a siloxane group {O} bonded to silicon {Si} of a perfluorooctylethylsilane group {C ₈ F ₁₇ C ₂ H ₄ Si—} { -Si-O-} bond. In this example, a solution of perfluorooctylethyltrichlorosilane {C ₈ F ₁₇ C ₂ H ₄ SiCl ₃ } dissolved in octamethylcyclotetrasiloxane {[(CH ₃ ) ₂ SiO] ₄ } in 1% solvent was used. Yes. The treatment solution is applied to the glass surface with a roll coater in a dry atmosphere at a dew point of −10 ° C., and the hydroxyl group {—OH} on the glass surface and the chlorosilane group {—SiCl ₃ } are reacted to form perfluorooctyl on the glass surface. A bond of a siloxane group {—Si—O—} in which silicon {Si} of the ethylsilane group {C ₈ F ₁₇ C ₂ H ₄ Si—} and oxygen {O} on the surface of the glass are bonded is generated. Thereafter, excess treatment liquid was blown off with an air blow to dry the surface. FIG. 3 shows a structural schematic diagram on the surface of the glass plate. With this structure, the surface of the glass has properties similar to those of a fluororesin, and therefore has a property of being difficult to adhere to adherends such as foods and seasonings, thereby preventing the door glass from being stained.
[0012]
When the test was conducted to drop 10 μl of a mixture of sugar and soy sauce on the surface of the door glass 1 treated with the membrane 2 and baked at 300 ° C. for 20 minutes and then wiped off with a wet cloth, the same dripping position 10 times, it was wiped off with a wet cloth. On the other hand, when a similar test was performed on a normal door glass without the membrane 2, the sugar soy sauce stuck and could not be wiped off at one time.
[0013]
Further, since the surface of the glass plate has a property like a fluororesin, the effect of reducing the friction coefficient of the surface and making it difficult to be damaged was also obtained.
[0014]
After the film 2 was formed, a corona discharge treatment was applied to the end face of the door glass. When the surface of the membrane 2 is taken as a reference of the horizontal plane, if the side without the membrane 2 is plus (+) and the side with the membrane 2 is minus (−), the end surface membrane is at an angle of ± 90 °. Can be removed. In FIG. 2, the schematic diagram of the corona discharge process to the door glass 1 was shown. It shows that the arc discharge 8 emitted from the probe 7 for corona discharge treatment is irradiated at an angle of −10 °, and the arc discharge 8 ′ emitted from the probe 7 ′ is irradiated at an angle of + 45 °. Yes.
[0015]
In order to remove only the film on the end face of the door glass, an angle of + 45 ° is optimal. When the angle is 20 ° or less, the film 2 on the film surface side can also be removed. To determine whether or not the glass on the end face of the glass has been removed, it can be determined by measuring the contact angle of the water droplet. The contact angle on the film 2 was 105 °. However, after the film was removed, the contact angle became 10 ° or less, and almost non-adhesiveness was removed. To make a simple determination, when an oily magic was applied, the magic was played on the film 2, but the magic did not play after the film was removed.
[0016]
In this embodiment, the power source voltage is 100 V, the input current is 8 A, the distance from the electrode voltage 2 × 12 kV end face to the corona discharge treatment probe 7 is about 5 mm, the processing angle is −5 °, and the electrode moving speed is 200 mm / second. Then, about 3 mm of film | membrane was able to be removed from the end surface and the edge of the film surface. This corresponds to the film removal unit 6.
[0017]
The corona discharge process will be described below. Corrugated metal wire electrodes are arranged close to each other on the probe for corona discharge treatment, and each is connected to the secondary winding of the high-voltage transformer. This transformer converts the power supply voltage to a high voltage of 12 kV. As power is supplied to the electrodes, electrical arcing occurs only at the electrode tips that are closest to each other. A constant flow of air supplied by the blower deflects the direction of the arc discharge and causes a spread along the saddle curve of the electrode. A certain amount of arc discharge is delivered at a rate of 50-60 cycles per second. The performance of the arc discharge spread depends on the secondary voltage of the transformer, the air velocity generated in the blower and the electrode geometry. The higher the voltage and the higher the speed, the farther the arc discharge spreads. However, if the flow rate of the supplied air is too high, the arc discharge will be broken faster than necessary, and the effective processing width will be reduced. A continuous arc discharge generates a corona (discharge) consisting of ions with high energy. It is considered that the siloxane bond or the like of the film 2 is cut by the energy field of the corona and the film can be removed.
[0018]
When the film 2 is formed on the surface of the door glass 1 with a roll coater, the width of the roll coater is made to coincide with the glass in order to prevent the treatment solution from entering the end surface of the door glass, and only the glass surface is coated with the end surface. Therefore, it is necessary to accurately manage the position where the roll coater comes in contact with, or to detect a film not formed on the end face. Taking into account the dimensional crossing of the glass, it is difficult to align the positions, and the solvent of the processing solution tends to vaporize with a boiling point of about 50 ° C., so it is inevitable that the processing solution adheres to the end face.
[0019]
In order not to apply the treatment solution to the end face, there is also a method of masking the end face in advance. A method is also conceivable in which a film is formed on the end face with polyvinyl alcohol or the like, and thereafter the treatment solution is applied and dried with a roll coater, and then the polyvinyl alcohol on the end face is removed by washing or the like.
[0020]
As a method for removing the film 2, a method of polishing the glass and removing the whole glass of the base material, a method of dissolving the glass with a chemical such as alkali, or a method of removing the film 2 by cutting the siloxane bond can be considered. These methods require more complicated processes because post-treatment such as washing and drying is required.
[0021]
Even when 500 ml of boiling water was placed in the cabinet and heated at 500 W for 30 minutes in the steam test using the above door glass stain prevention method, the invasion of steam did not occur. In addition, the detergent solution did not enter even after the detergent solution was poured onto the door glass 1 and the adhesive 3 and left for 12 hours. This is probably because the door glass 1 and the silicone putty adhesive 3 are bonded to each other by the corona discharge treatment, so that the intrusion of steam, detergent or the like from the bonded portion does not occur.
[0022]
【The invention's effect】
As described above, according to the high-frequency cooking device of the present invention, the film is removed by corona discharge, removed by corona discharge treatment, and the corona discharge treatment is performed at an angle with respect to the end surface of the door glass during the removal. provided in which it was decided to remove by adjusting the amount of removing the film. According to the said invention, it can be set as the door glass which the adhesion | attachment with the putty and the glass surface which ensured the adhesion | attachment of a putty and the glass surface without a vapor | steam permeating from the interface of a putty and glass, and is hard to stick. In addition, since the surface of the glass plate has a property like a fluororesin, the friction coefficient of the surface becomes small and the effect of being hard to be damaged is also obtained.
[Brief description of the drawings]
FIG. 1 is an enlarged view of a main part of a door portion of a microwave oven according to an embodiment of the present invention. FIG. 2 is a schematic diagram of corona discharge treatment to the door glass of the microwave oven. Schematic structure diagram of [Symbols]
1 Door glass 2 Film 3 Silicone putty (adhesive)
4 Door frame 6 Membrane removal part

Claims (2)

Film is formed having a fluoroalkyl group and a siloxane bond to the surface of the door glass, the film formed on the end surface of the door glass is removed by corona discharge treatment, an end face and the door frame of the door glass in the adhesive body A method of preventing dirt on the door glass of the microwave oven to be bonded. Film is formed having a fluoroalkyl group and a siloxane bond to the surface of the door glass, the film formed on the end face of the door glass is removed by corona discharge treatment, a corona discharge treatment to the end surface of the door glass when the removal A method for preventing soiling of door glass of a microwave oven, in which an end face of the door glass and a door frame are bonded with an adhesive after an angle is provided and the amount of the film to be removed is adjusted and removed.

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