JP3937594B2 - Manufacturing method of anti-fouling door glass for microwave oven - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a cooking device such as a microwave oven and a microwave oven, and more particularly to a method for manufacturing a soil-preventing door glass for a microwave oven in which a 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 silicone. A configuration in which the periphery is bonded with a putty is mainly 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 door glass of a conventional microwave oven is difficult to wipe off when oil or the like from food is stuck with heat. 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 provides a step of providing a non-adhesive film having a fluoroalkyl group and a siloxane bond on the surface of a door glass, and the door glass facing the door glass and the conductor plate on a conductor plate. removing by corona discharge treatment film formed on the end surface of the door glass to cause a corona discharge between the end wire and said conductive plate is disposed parallel to the vicinity of the non of the door glass By adopting a method for producing a dirt-preventing door glass for a microwave oven having a process of adhering the edge part from which the adhesive film has been removed and the door frame, steam or the like may enter from the interface between the adhesive body such as a silicone putty and the glass. It is possible to manufacture a door glass that is difficult to adhere to the dirt and ensures adhesion between the adhesive and the glass surface.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes a step of providing a non-adhesive film having a fluoroalkyl group and a siloxane bond on the surface of the door glass, and the door glass on the conductor plate and the conductor plate are arranged in parallel near the edge of the door glass. A step of causing corona discharge between the provided wire and the conductor plate to remove the film formed on the end face of the door glass by corona discharge treatment; and an end portion from which the non-adhesive film of the door glass is removed ; It was set as the manufacturing method of the dirt prevention door glass of the microwave oven which has the process of adhere | attaching a door frame.
[0006]
And it can be set as the manufacturing method which provides the door glass which does not permeate vapor | steam etc. from the interface of a putty and glass, and has the adhesion | attachment of the putty and the glass surface and which is hard to adhere to the dirt by the said method.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0008]
Example 1
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. FIG. 2 is a schematic diagram of the corona discharge treatment for the door glass 1.
[0009]
The door glass 1 is provided with a non-adhesive film (hereinafter abbreviated as a film) 2, and the film 2 is provided between the door frame 4 and the door glass 1, a film removing portion 6 from which the film 2 has been removed by corona discharge treatment. It is bonded to a door frame 4 having punching holes 5 by an adhesive 3 that is coated with silicone putty and heat-cured. The coating range of the silicone putty is sufficient in the part where the film 2 is removed, but the film removal part 6 is not limited to this range in manufacturing, and may be applied in a form including a part of the film 2.
[0010]
Moreover, although this punching hole part 5 is obtained by an integrated structure with a manufacturing top frame, in this invention, it does not need to have this punching hole part.
[0011]
The film 2 has a structure having a fluoroalkyl group and a siloxane bond, and a bond of a siloxane group {—Si—O—} in which oxygen {O} is bonded to silicon {Si} of a perfluorooctylethylsilane group {C8F17C2H4Si—}. have. In this example, a solution obtained by dissolving 1% of perfluorooctylethyltrichlorosilane {C8F17C2H4SiCl3} in octamethylcyclotetrasiloxane {[(CH3) 2SiO] 4} solvent is used. The treatment solution is applied to the glass surface with a roll coater in a dry atmosphere having a dew point of −10 ° C., and the hydroxyl group {—OH} and chlorosilane group {—SiCl 3} on the glass surface are reacted to form perfluorooctylethyl on the glass surface. A bond of a siloxane group {-Si-O-} in which silicon {Si} of the silane group {C8F17C2H4Si-} 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.
[0012]
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. The film 2 having such a structure is a thin film of several nanometers as can be seen from FIG.
[0013]
As the door glass of the microwave oven, tempered glass is usually used. This is to increase the strength of the glass and make it difficult to break. Tempered glass includes thermally tempered glass and chemically tempered glass. Thermally tempered glass heats soda glass to near the softening point, rapidly cools the glass surface, generates compressive stress on the glass surface, and improves strength. Chemically tempered glass causes a similar compressive stress to be caused by chemicals. Heat-tempered glass is also called air-cooled tempered glass. Since heating is performed up to about 650 ° C., dirt such as oil on the glass surface is burned out. In treating the above-mentioned treatment solution, it is desirable that the glass surface is free from oil and other dirt, and if there is oil and other dirt, it is desirable to perform the treatment after washing.
[0014]
When a test was conducted to drop 10 μl of a mixture of sugar and soy sauce on a 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.
[0015]
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.
[0016]
After the film 2 was formed, a corona discharge treatment was performed on the end surface of the door glass 1. When the surface of the non-adhesive film 2 is used as a reference of the horizontal plane, if the side without the film 2 is plus (+) and the side with the film 2 is minus (−), the angle of the end face is within ± 90 °. The film 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.
[0017]
An angle of + 45 ° is optimal for removing only the film of the film removing portion 6 on the end face of the door glass 1. When the angle is 20 ° or less, the film 2 on the film surface side can also be removed. It can be determined by measuring the contact angle of water droplets to determine whether the film 2 on the end face of the glass has been removed. The contact angle on the film 2 was 105 °. However, after the film 2 was removed, the contact angle became 10 ° or less, and almost non-adhesiveness was removed. For simple determination, when an oily magic was applied, the magic was repelled on the film 2, but the magic did not repel after the film was removed.
[0018]
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 non-adhesive film 2 could be removed from the end face and the end of the film face. This corresponds to the film removal unit 6.
[0019]
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 of the film 2 is cut by the energy field of the corona and the film can be removed.
[0020]
When the film 2 is formed on the surface of the door glass 1 with a roll coater, in order to prevent the treatment solution from entering the end surface of the door glass 1, the width of the roll coater is matched with that of the glass, and only the surface of the door glass 1 is used. It is necessary not to paint the end face, and it is necessary to accurately manage the position where the roll coater contacts, or to detect that a film is not formed on the end face. Taking the dimensional tolerance of the door glass 1 into consideration, it is difficult to align the positions, and the solvent of the processing solution is likely to vaporize with a boiling point of about 50 ° C., so it is unavoidable that the processing solution adheres to the end face.
[0021]
In order not to apply the treatment solution to the end face, there is also a method of masking the end face in advance. It is also conceivable to form a film with polyvinyl alcohol on the end face, then apply the treatment solution on a roll coater and dry it, and then remove the polyvinyl alcohol on the end face by washing or the like.
[0022]
In addition, as a method of removing the film 2, a method of polishing the door glass 1 to remove the whole glass of the base material, a method of melting the glass with an alkaline chemical, or a method of removing the siloxane bond of the film 2 by cutting is considered. However, these methods require more complicated processes because they require post-treatment such as washing and drying.
[0023]
In the present invention, the film 2 is a thin film of several nanometers, and the film 2 is bonded to the glass surface of the base material through a chemical bond. Since the film 2 is thin, the chemical bond between the film 2 and the substrate can be broken by the energy of corona discharge.
[0024]
In the case of a thick film, only the film on the surface portion of the thick film can be removed, but since it is a thin film, corona discharge that can be cut from the chemical bond portion is considered suitable.
[0025]
The schematic diagram of the other Example of the corona discharge process to the door glass 1 was shown in FIG. 4 and FIG. 4 is a view as seen from the direction of the end face of the door glass 1, FIG. 5 is a view as seen from a cross-sectional direction of the door glass 1, and FIG. 3 shows a direction in which the viewing angle is changed by 90 degrees. is there.
[0026]
An iron plate is used as the conductor plate 9, the door glass 1 having the film 2 is placed on an insulating plate 10 made of polytetrafluoroethylene, a high frequency current of 0.25 kV is passed through the electrode wire 11, and the electrode wire 11 and the conductor The corona discharge is generated between the plates 9 and the end surface of the door glass 1 is irradiated with the corona discharge, whereby the film removal unit 6 is completed. When the distance between the electrode wire 11 and the end surface of the door glass 1 and the film surface is optimally selected, the film removal portion 6 that is necessary for adhesion to the silicone putty can be completed.
[0027]
When the distance from the end surface of the door glass 1 is L and the distance from the film surface is H, 2 mm <L <5 mm, 2 mm <H <5 mm, and the film surface side width Lx of the film removal unit 6 is removed by 1 mm to 3 mm. did it. When the range of L and H is appropriately selected, the range of Lx necessary for adhesion to the silicone putty can be removed, and the end face portion of the film removing portion 6 can also be removed.
[0028]
In this embodiment, the irradiation time of the corona discharge is 3 seconds. However, when the irradiation time is increased, the width Lx on the film surface side of the film removing unit 6 can be changed. The insulating plate 10 is for ensuring insulation between the conductor plate 9 and the door glass 1.
[0029]
If the length of the electrode wire 11 in the corona discharge treatment is made to correspond to the length of the door glass 1, it is not necessary to move the probe 7 as in the method of moving the probe 7 and performing the corona discharge treatment. Corona discharge treatment can be performed in time.
[0030]
Even when the door glass 1 manufactured by the method for manufacturing a door glass for preventing contamination of a microwave oven was used and 500 ml of boiling water was placed in the chamber and the steam test was heated at 500 W for 30 minutes, 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 corona discharge treatment, so that the intrusion of steam, detergent, or the like from the bonded portion does not occur.
[0031]
【The invention's effect】
As described above, the method for producing the anti-stain door glass of the microwave oven according to the present invention includes the step of providing a non-adhesive film having a fluoroalkyl group and a siloxane bond on the surface of the door glass, and the door glass and the conductor plate on the conductor plate. The film formed on the end surface of the door glass by corona discharge between the wire and the conductor plate arranged in parallel near the end of the door glass opposite to the door glass is removed by corona discharge treatment. And the manufacturing method of the dirt prevention door glass of the microwave oven which has the process of adhere | attaching the edge part which removed the non-adhesion film | membrane of the said door glass , and a door frame.
[0032]
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 of a putty and the glass surface without vapor | steam permeating from the interface of a putty and glass, and is hard to adhere to dirt. Further, since the surface of the glass plate has a property like a fluororesin, an effect that the coefficient of friction of the surface is small and the surface is hardly damaged can be obtained.
[Brief description of the drawings]
FIG. 1 is an enlarged view of a main part of a door part of a microwave oven according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a corona discharge treatment to the door glass of the microwave oven. Schematic diagram of the structure on the surface [Fig. 4] Schematic diagram of another corona discharge treatment to the door glass of the microwave oven [Fig. 5] Schematic diagram of another corona discharge treatment to the door glass of the microwave oven [Explanation of symbols]
1 Door glass 2 Non-adhesive film 3 Silicone putty (adhesive)
4 Door frame 6 Membrane removal part 9 Conductor plate 10 Insulating plate 11 Electrode wire

Claims (1)

A step of providing a non-adhesive film having a fluoroalkyl group and a siloxane bond on the surface of the door glass; a wire disposed in parallel in the vicinity of the edge of the door glass facing the door glass and the conductor plate on the conductor plate; A step of causing corona discharge between the conductor plate and removing the film formed on the end face of the door glass by corona discharge treatment; and an end portion of the door glass from which the non-adhesive film is removed and the door frame. The manufacturing method of the antifouling door glass of the microwave oven which has the process to adhere | attach.

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