JPH0592994U - Oven microwave door panel structure - Google Patents

Abstract

(57) [Summary] [Objective] To provide a door panel structure for an oven microwave oven which is lightweight, low in cost and excellent in durability. A door panel structure for an oven microwave oven, the main part of which is a laminated body composed of an inner transparent body, an electromagnetic wave shield member, and an outer transparent body that is openably and closably attached to an open portion of an oven microwave oven main body. A door panel structure for an oven microwave oven, wherein the transparent body is composed of a polyether sulfone film adhered to the electromagnetic wave shield member via a silicon adhesive.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a door panel structure for an oven microwave oven, and more particularly to a door panel structure for an oven microwave oven that is lightweight, low cost and excellent in durability.

[0002]

[Prior Art]

 This type of microwave oven includes an oven microwave oven main body a having an opening a1 on the front side as shown in FIGS. 2 and 3, and a door panel structure b attached to the opening a1 so as to be openable and closable. It is known that the main part is composed of.

As shown in FIG. 4, the conventional door panel structure b has an outer transparent body b1 made of heat-resistant glass and an electromagnetic wave inside the oven microwave oven main body a which is laminated on the outer transparent body b1. An electromagnetic wave shielding member b2 made of a coated steel plate provided with a mesh m so as not to leak to the inside of the oven microwave oven a so that the inside of the microwave oven body a can be seen, and an inner transparent body b4 made of heat-resistant glass provided through a heat insulating space b3. The main part was constituted by the door frame b5 that holds these members.

However, the door panel structure having such a structure has a drawback that the weight is heavy and the operability is poor, and an expensive heat-resistant glass is required, so that the manufacturing cost is high. It was

Under such a technical background, in the microwave oven not having the above-mentioned oven function, a door panel structure which is lightweight and low in cost as shown in FIG. 5 has been developed.

That is, the door panel structure includes an outer transparent body b1 made of polycarbonate, an electromagnetic wave shield member b2 made of a coated steel plate provided with a mesh m as in the conventional case, and an acrylic adhesive b6 for the electromagnetic wave shield member b2. The inner transparent body b4 made of poly (ethylene terephthalate) film and the door frame b5 holding them are the main parts, and polycarbonate or polyethylene terephthalate is used instead of heat resistant glass. By applying the film, it was possible to reduce its weight and cost.

Regarding an oven microwave oven having an oven function, in Japanese Patent Application No. 3-89390 filed by the present inventors, a polyimide film or a polyparabanic acid film is used as an inner transparent body, which increases weight. We solved the drawback of poor operability. However, although all of these films have excellent transparency, they are not yellow or amber, which makes it inconvenient to observe the condition of food in the microwave oven.

In response to this, in Japanese Patent Application No. 3-100383, a transparent and colorless polyethylene naphthalate film or a heat-resistant polyethylene terephthalate film is used as an inner transparent body to facilitate observation in an oven microwave oven. I chose However, when high heat was applied, a slight amount of white powder, which was an oligomer, was observed to be precipitated in both of them, and the heat-resistant polyethylene terephthalate film was thermally deteriorated after 500 hours or more of use, and the film itself became brittle. It had the drawback that it would break easily.

[0009]

[Problems to be solved by the device]

 By the way, when the door panel structure having the above-mentioned structure used in this microwave oven is applied to an oven microwave oven having an oven function as it is, the temperature inside the oven microwave oven body is about 170 to 300 ° C. Yes, because the temperature is much higher than the temperature inside the microwave oven, the acrylic adhesive b6 deteriorates due to heat, causing a decrease in its adhesive strength.In addition, an inner transparent body b4 made of a polyethylene terephthalate film is also used. There is a problem in that the inner transparent body b4 floats and peels off from the electromagnetic wave shield member b2 due to heat shrinkage, which act on each other to make it unusable in a short period of time.

For this reason, as a door panel structure for an oven microwave oven, a structure in which heat-resistant glass is applied to the inner transparent body is still used, and its weight is heavy, so that the operability is poor and the manufacturing cost is low. There was a problem that was expensive.

The present invention has been made in view of such problems, and an object thereof is to provide a door panel structure for an oven microwave oven which is lightweight, low in cost and excellent in durability. ..

[0012]

[Means for Solving the Problems]

 That is, the invention according to claim 1 is an oven microwave oven in which a main part is constituted by a laminated body which is openably and closably attached to an open portion of an oven microwave oven main body, and includes an inner transparent body, an electromagnetic wave shield member, and an outer transparent body. On the premise of the above door panel structure, the inside transparent body is constituted by a polyether sulfone film adhered to the electromagnetic wave shield member via a silicone adhesive.

In such a technical means, the outer transparent body provided on the outer side of the door panel structure is not exposed to a higher temperature than the inner transparent body. The applied polycarbonate can be applied, and the weight is slightly increased. However, it does not matter if heat-resistant glass is applied.

Further, as the electromagnetic wave shield member, a coated steel plate or the like provided with a mesh can be applied as it is as in the conventional case.

When the pressure-sensitive adhesive used for the inner transparent body of the door panel structure of the present invention is not a silicone pressure-sensitive adhesive, for example, a synthetic rubber-based pressure sensitive adhesive or an acrylic pressure-sensitive adhesive, these heat resistances are synthetic rubber-based pressure-sensitive adhesives. The temperature in the oven microwave oven is about 200-300 ° C locally, so the yellowing of the adhesive itself changes. Occurs, and the adhesive strength is lost, causing peeling of the inner transparent body.

[0016] In comparison, silicone-based adhesives have a linear structure and are related to film formation and cohesive force, namely, silicone gum, and have a complicated three-dimensional structure. A silicone composition composed of a silicone resin, which is a force-related component, is crosslinked using a catalyst and has excellent heat resistance.

Here, one of the silicone-based adhesives used for the inner transparent body of the present invention is a silicone resin and a silicone in which the ratio of the silicone resin to the solid content is 50% by weight or more. It is a cross-linking reaction product of gum, and the tackiness of the adhesive is high, and the method of attaching it to the electromagnetic wave shield member only needs to apply pressure.

Further, when the silicone-based adhesive has a silicone resin content of 64% by weight or more, the tack tends to decrease at room temperature, and the tack-free adhesive causes tack when heated at 100 ° C. or higher. It has the property of Therefore, when the inner transparent body laminated with this adhesive is attached to the electromagnetic wave shield member, heating is required at the same time as the pressure bonding.

In this case, when the proportion of the silicone resin is less than 50% by weight, the adhesive strength tends to be insufficient and the tack tends to decrease, which may cause floating or peeling of the pressure-sensitive adhesive sheet, which is not practical.

If the coating amount of the pressure-sensitive adhesive is too thick, the permeability will be poor, and if it is too thin, sufficient adhesive force will not be obtained, so 100 to 10 μm, preferably 80 to 20 μm is suitable.

On the other hand, the polyether sulfone film used for the inner transparent body of the present invention has a heat resistance of about 180 ° C. Specifically, the product name "FS-1300" manufactured by Sumitomo Bakelite Co., Ltd., the product name "TALPA-1000" manufactured by Mitsui Toatsu Chemicals, Inc., and the like can be used.

Since the linear expansion coefficient of the film of the door panel structure of the present invention using the heat resistant film is 3 × 10 ⁻⁵ cm / cm / ° C. or more, the temperature inside the oven microwave oven main body is It is preferably applied to an oven microwave oven at 200 ° C or lower. When it is used at a temperature higher than 200 ° C., there is a possibility that problems such as floating and peeling from the electromagnetic wave shield member due to expansion of the film may occur.

[0023]

[Action]

 According to the invention of claim 1, the inner transparent body of the door panel structure is made of a polyether sulfone film adhered to the electromagnetic wave shield member via a silicone-based adhesive. Compared with the conventional door panel structure whose transparent body is made of heat-resistant glass, the weight and cost can be significantly reduced.

[0024]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a cross-sectional structure of the door panel structure according to the embodiment. The door panel structure 10 includes an outer transparent body 11 made of heat-resistant glass and a mesh laminated on the outer transparent body 11. The electromagnetic wave shielding member 12 made of a coated steel plate provided with and the door frame 15 holding each member adhered to the electromagnetic wave shielding member 12 through the silicone adhesive layer 13 constitutes a main part thereof. Is what

[Example 1] A polyether sulfone film (PES; trade name "FS-1300" manufactured by Sumitomo Bakelite Co., Ltd.) cut into a size of 170 x 320 mm with a thickness of 50 µm was used as a base material, and silicone corn gum and a silicone resin were used. A polyether sulfone film having a 30 μm thick silicone-based adhesive layer 13 formed by applying a silicone-based adhesive obtained by crosslinking a silicone composition having a weight ratio of 29:71 The inner transparent body 14 was sought.

Next, with respect to the electromagnetic wave shield member 12 made of a coated steel plate on which the outer transparent body 11 made of heat-resistant glass is laminated, the inner transparent body 14 is so contacted that the silicone adhesive layer 13 side is in contact with the electromagnetic wave shield member 12. Then, the members were fitted into the door frame 15 under pressure while being heated to 120 ° C., and these members were fitted into the door frame 15 to manufacture the door panel structure of the oven microwave oven as shown in FIG.

Example 2 The silicone gum and the silicone resin were replaced by a crosslinked silicone-based adhesive in which the silicone composition had a weight ratio of 29:71, and the silicone gum and the silicone resin were in a weight ratio. The procedure is substantially the same as in Example 1 except that a silicone-based pressure-sensitive adhesive obtained by crosslinking a silicone composition of 36:64 is applied to form a silicone-based pressure-sensitive adhesive layer 13 having a thickness of 30 μm.

[Example 3] [0029] Instead of the silicone adhesive obtained by crosslinking the silicone composition in which the ratio of the silicone gum and the silicone resin is 29:71 by weight, the ratio of silicone gum and silicone resin is by weight. Example 43 except that a silicone-based pressure-sensitive adhesive obtained by crosslinking a silicone composition consisting of 43:57 was applied to form a silicone-based pressure-sensitive adhesive layer 13 having a thickness of 30 μm, and that the pressure-sensitive adhesive was applied at room temperature. It is almost the same.

Comparative Example 1 The procedure of Example 1 is substantially the same as that of Example 1 except that an acrylic adhesive is applied instead of the silicone adhesive to form an acrylic adhesive layer having a thickness of 50 μm.

Comparative Example 2 A silicone composition having a weight composition ratio of 70:30 instead of the silicone adhesive obtained by crosslinking the silicone composition in which the ratio of the silicone gum and the silicone resin is 29:71. Example 1 is substantially the same as Example 1 except that a system adhesive is applied to form a 30-μm thick silicone-based adhesive layer.

Comparative Example 3 A polyethylene terephthalate (PET) film having a thickness of 50 μm and cut to 170 × 320 mm was used in place of the polyether sulfone film, and acrylic was used in place of the silicone adhesive. Example 1 is substantially the same as Example 1 except that a 50 μm thick acrylic adhesive layer was formed by applying a system adhesive.

Comparative Example 4 The same as Example 1 except that a polyethylene terephthalate (PET) film having a thickness of 50 μm and cut into 170 × 320 mm was used in place of the above polyether sulfone film. ..

[Comparative Example 5] Abbreviated as Example 1 except that a polyether ether ketone (PEEK) film having a thickness of 50 μm and cut into 170 × 320 mm was used instead of the above polyether sulfone film. It is the same.

Comparative Example 6 Substantially the same as Example 1 except that a polyarylate (PAR) film having a thickness of 50 μm and cut to 170 × 320 mm was used in place of the above polyether sulfone film. Is.

[Confirmation Test] Next, in order to confirm the characteristics of the door panel structure according to each example and the door panel structure according to each comparative example, each of these door panel structures was incorporated into an oven microwave oven main body, and For each door panel structure, a time mounting test was performed to check whether the inner transparent body was floating, peeling, heat shrinking, yellowing, etc., and also checking the change in transparency.

The results are shown in Table 1 below.

[0038]

[Table 1]

In the table, “◯” indicates that the inside transparent body did not float, peel off, heat shrink, or yellow, and the transparency does not change. The symbol Δ indicates that floating, peeling, heat shrinkage, and yellowing of the inner transparent body were slightly observed. Regarding x, floating, peeling, heat shrinkage, and yellowing of the inner transparent body were observed, and the transparency was deteriorated.

[Evaluation] As is clear from the results shown in Table 1, the door panel structures according to the examples do not cause floating, peeling, heat shrinkage, yellowing, etc. of the inner transparent body, and also have a change in transparency. It was confirmed that there was no change and it was extremely excellent.

On the other hand, in the door panel structures according to Comparative Example 1 and Comparative Examples 3 to 4, the inner transparent body was greatly floated, peeled off, thermally shrunk and yellowed, and the transparency was also changed. It was confirmed that it could not be applied to the microwave oven.

The door panel structure according to Comparative Example 2 was obtained by applying a polyether sulfone (PES) film and a silicone-based adhesive, and the yellowing and transparency items were the same as those of the examples. However, the adhesive strength was insufficient due to the low silicone resin ratio of the adhesive, and the inner transparent body was observed to float, peel off, and heat shrink, which confirmed that it could not be applied to the microwave oven.

On the other hand, regarding the door panel structure according to Comparative Example 5 to which the polyether ether ketone (PEEK) film was applied, the items of floating, peeling, heat shrinkage, and yellowing of the inner transparent body were the same as those of the example. However, it was originally confirmed that the transparency was extremely poor and that it could not be applied to an oven microwave oven. The door panel structure according to Comparative Example 6 to which the polyarylate (PAR) film was applied had peeling, yellowing, and transparency items similar to those of the example, but the inner transparent body floated, and heat shrinked. It was confirmed that it was not applicable to the microwave oven.

[0044]

[Effect of the device]

 According to the invention as claimed in claim 1, compared with the conventional door panel structure whose inner transparent body is made of heat-resistant glass, the weight and cost can be significantly reduced. Therefore, the operability and the door panel structure can be improved. Has the effect that it can be manufactured at low cost.

Further, the silicone-based pressure-sensitive adhesive and the polyethersulfone film constituting the internal transparent body are excellent in heat resistance, and this film also has a linear expansion coefficient of 4.4 × 10 ⁻⁵ cm / cm. It is as small as / ° C, and heat shrinkage does not easily occur even when the internal temperature of the microwave oven main body becomes high. It is possible to prevent the phenomenon of peeling from the member, and thus it has the effect of significantly improving the durability of the door panel structure.

[0046]

[Brief description of drawings]

FIG. 1 is a sectional view of a door panel structure of an oven microwave oven according to an embodiment.

FIG. 2 is a perspective view of an oven microwave oven.

FIG. 3 is a perspective view of the oven microwave oven with the door panel structure opened.

FIG. 4 is a sectional view of a door panel structure in a conventional microwave oven.

FIG. 5 is a sectional view of a door panel structure in a conventional microwave oven.

[Explanation of symbols]

 10 Door Panel Structure 11 Outer Transparent Body 12 Electromagnetic Wave Shielding Member 13 Silicone Adhesive Layer 14 Inner Transparent Body 15 Door Frame

Front page continuation (72) Inventor Manabu Morihama 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Koichi Hotta 1-5-1 Taito, Taito-ku, Tokyo Toppan printing Co., Ltd. (72) Inventor Masao Nakajima 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. A door panel structure for an oven microwave oven, the main part of which is a laminated body composed of an inner transparent body, an electromagnetic wave shield member, and an outer transparent body, which is openably and closably attached to an open portion of an oven microwave oven body. A door panel structure for an oven microwave oven, wherein the inner transparent body is composed of a polyether sulfone film adhered to an electromagnetic wave shield member via a silicone adhesive. 2. An oven microwave oven door panel, characterized in that the main component of the silicone-based pressure-sensitive adhesive is a cross-linking reaction product of a silicone resin and a silicone gum in which the ratio of the silicone resin to the solid content is 50% by weight or more. Structure. 3. An oven microwave oven door panel, characterized in that the main component of the silicone-based pressure-sensitive adhesive is a cross-linking reaction product of a silicone resin and a silicone gum in which the ratio of the silicone resin to the solid content is 64% by weight or more. Structure.