JP2014011014A - Heating cooker and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating cooker that has a water-soluble high polymer layer interposed between a heat-resistant resin layer and an adhesive layer and that prevents poor appearance, and to provide a method for manufacturing the same.SOLUTION: A heating cooker includes a top plate 2 having: an inorganic pigment layer 7 that is formed on a rear surface of a transparent crystallized glass plate 6; and a heat-resistant resin layer 8 that is formed on the inorganic pigment layer 7. The top plate 2 is bonded on a rear side thereof to an under frame 5 with an adhesive. A water-soluble high polymer layer 9 is interposed between the heat-resistant resin layer 8 and an adhesive layer 10.

Description

  The present invention relates to a cooking device provided with an electromagnetic heating device and a method for manufacturing the same, and more particularly to a bonding structure of the top plate.

  Generally, a low thermal expansion black crystallized glass or a low thermal expansion transparent crystallized glass is used for the top plate of an IH cooking heater which is a cooking device equipped with an electromagnetic heating device. In this type of IH cooking heater, since there is no lighting of the heater part which becomes a mark at the time of heating, a light emitting diode or the like is arranged in the vicinity of the heating part, and the heating power can be confirmed via the top plate. However, when low thermal expansion black crystallized glass is used for the top plate, there is a problem that the light of the light emitting diode is not conspicuous and difficult to see. On the other hand, in the case of using a low thermal expansion transparent crystallized glass for the top plate, it is necessary to provide a light-shielding film except for the portion where the light emitting diode is displayed so that the internal structure of the cooking utensil cannot be seen. Furthermore, the top plate with the light-shielding coating on the back is fixed to the top frame and underframe by the adhesive applied on the light-shielding coating, so that the adhesive soaks into the light-shielding coating and looks like a stain when viewed from the surface. There was also a problem that the appearance was poor.

  In view of such a situation, a conventional light-shielding film made of inorganic pigment and glass is formed on the surface of a low thermal expansion transparent crystallized glass plate, and a heat-resistant resin layer is formed on the surface of the light-shielding film. A top plate has been proposed (see, for example, Patent Document 1). In the conventional cooking top plate described in Patent Document 1, since the heat-resistant resin layer is formed on the surface of the light-shielding film, the low molecular component of the adhesive is prevented from penetrating into the light-shielding film, resulting in poor appearance. Occurrence is suppressed.

  However, in the conventional cooking top plate described in Patent Document 1, the heat resistant resin layer may be deteriorated due to an excessively high temperature state such as empty cooking during cooking, and cracks may occur. When a crack occurs in the heat-resistant resin layer, the low molecular component of the adhesive penetrates into the inorganic pigment layer through the crack generated in the heat-resistant resin layer, and when seen from the surface on the cooking surface side of the top plate, the black stain This will cause appearance defects.

  Therefore, a conventional cooking top plate in which an inorganic pigment layer is formed on the surface of a low thermal expansion transparent crystallized glass plate and a silica-containing inorganic coating layer is formed on the surface of the inorganic pigment layer has been proposed (for example, Patent Documents). 2). In the conventional cooking top plate described in Patent Document 2, the silica-containing inorganic coating layer is not deteriorated even by an excessively high temperature state such as emptying during cooking, and the low molecular component of the adhesive soaks into the inorganic pigment layer. This is prevented by the silica-containing inorganic coating layer, and occurrence of poor appearance is suppressed.

  Further, a method of containing a silane coupling agent in the heat-resistant resin layer, strengthening the bonding of the three-dimensional network structure forming the resin, and preventing cracks due to deterioration of the heat-resistant resin layer even when the top plate reaches a high temperature Is disclosed (for example, see Patent Document 3). According to Patent Document 3, it is possible to prevent the components of grease and adhesive at high temperatures from penetrating, and to prevent the occurrence of stains.

JP 2003-338360 A JP 2009-047406 A JP 2010-040171 A

In this type of IH cooking heater, as the performance is improved, the heating temperature rises and the temperature of the top plate becomes higher than before.
Therefore, in the conventional cooking top plate described in Patent Document 1, the heat resistant resin layer is more easily deteriorated, and the low molecular component of the adhesive permeates the inorganic pigment layer through the deteriorated heat resistant resin layer. There was a problem that the risk of appearance defects due to the increase in the appearance.

  On the other hand, in the conventional cooking top plate described in Patent Document 2, the silica-containing inorganic coating layer interposed between the inorganic pigment layer and the adhesive layer is a hard film. Cracks are likely to occur inside the inorganic pigment layer and the silica-containing inorganic coating layer due to the stress generated in the adhesive layer during cooking. And the crack generation | occurrence | production part sees as a white stain seeing from the surface by the side of the cooking surface of a top plate, and there exists a problem that an external appearance defect is caused.

  Furthermore, in the conventional cooking top plate described in Patent Document 3, since the bonding of the three-dimensional network structure of the heat-resistant resin layer is strengthened by the silane coupling agent and is a hard film, the adhesive is cured during shrinkage or cooking. Cracks are likely to occur inside the inorganic pigment layer and the heat-resistant resin layer due to the stress generated in the adhesive layer. Then, the cracked portion appears as a white stain when viewed from the cooking surface side surface of the top plate, resulting in a defect in appearance.

  The present invention has been made to solve such a problem, and a heating that can suppress the occurrence of poor appearance by interposing a water-soluble polymer layer between the heat-resistant resin layer and the adhesive layer. It aims at obtaining a cooking utensil and its manufacturing method.

  The cooking device according to the present invention includes a top plate in which a light shielding layer is formed on the back surface of a flat transparent crystallized glass and a heat resistant resin layer is formed on the light shielding layer, and the top plate is on the back surface side. Are fixed to the frame by an adhesive. A water-soluble polymer layer is interposed between the heat-resistant resin layer and the adhesive layer.

  According to this invention, the water-soluble polymer film interposed between the heat-resistant resin layer and the adhesive layer is formed into a dense film, which can prevent the low-molecular component of the adhesive from permeating and adhere to the adhesive layer. Alleviates the stress generated in the agent layer. Therefore, even if the heat-resistant resin layer deteriorates by being exposed to high temperatures during cooking and cracks occur, the low-molecular components of the adhesive cannot penetrate into the cracks in the heat-resistant resin layer, resulting in appearance defects. It is suppressed. Furthermore, the stress generated in the adhesive layer during the curing shrinkage of the adhesive or during cooking is relieved, and the occurrence of cracks in the heat resistant resin layer is suppressed. Therefore, appearance defects due to cracks generated in the light shielding layer and the heat resistant resin layer are suppressed.

It is a perspective view which shows the electromagnetic cooking appliance which concerns on one embodiment of this invention. It is principal part sectional drawing which shows the adhesion structure of the top plate in the electromagnetic cooking appliance which concerns on one embodiment of this invention. It is principal part sectional drawing which shows the adhesion structure of the top plate in the electromagnetic cooking appliance which concerns on the embodiment of one embodiment of this invention.

  Hereinafter, preferred embodiments of the cooking device of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an electromagnetic cooking utensil according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part showing a top plate bonding structure in the electromagnetic cooking utensil according to an embodiment of the present invention.

  In FIG. 1, an IH cooking heater as an electromagnetic cooker includes a box-shaped casing 1 having an opening at the top, a top plate 2 disposed so as to cover the top of the casing 1, and an outer peripheral portion of the top plate 2. And a frame 4 that holds at least one side thereof. This IH cooking heater is a built-in type IH cooking heater provided with a cooking pan mounting portion 3a by two-port induction heating and a cooking pan mounting portion 3b by one-port radial heater heating. And although not shown in figure, the coil is arrange | positioned in the housing | casing 1 so that the back surface of each cooking pan mounting part 3a of the top plate 2 may be adjoined. And an electric current is sent through a coil, a magnetic force line is produced | generated, an eddy current is produced in to-be-heated objects, such as a pan and a flan bread | pan mounted in the top plate 2, and a to-be-heated object self-heats and cooks. A ribbon-like metal heating element is embedded under the cooking pan mounting portion 3 b of the top plate 2.

  Next, the connection structure of the top plate 2 will be described with reference to FIG.

The top plate 2 is a rectangular flat transparent crystallized glass 6, an inorganic pigment layer 7 as a light shielding layer formed on the entire back surface of the transparent crystallized glass 6, and the entire surface of the inorganic pigment layer 7. The formed heat-resistant resin layer 8 is provided. Further, the water-soluble polymer layer 9 is coated on the outer peripheral edge of the surface of the heat-resistant resin layer 8 with a predetermined width.
The top plate 2 configured as described above is held by adhering and fixing an outer peripheral edge portion of the back surface thereof to an underframe 5 as a frame with an adhesive. Thus, the water-soluble polymer layer 9 is interposed between the heat resistant resin layer 8 and the adhesive layer 10.

  When the under frame 5 is omitted, as shown in FIG. 3, the bent piece at the lower end of the frame 4 is extended, and the top plate 2 has its back outer peripheral edge bonded to the bent piece. It will be fixed. The water-soluble polymer film 9 may be formed on the entire surface of the heat resistant resin layer 8.

Here, since the transparent crystallized glass 6 is repeatedly heated and cooled, it is required to have low thermal expansion, and the average linear thermal expansion coefficient at 30 to 750 ° C. is particularly −10 to + 30 × 10 ^−7. It is preferable to use those in the range of / ° C.
The inorganic pigment layer 7 is made of an inorganic pigment and glass, and is porous in order to prevent the occurrence of cracks due to a difference in thermal expansion from the transparent crystallized glass 6. The material of the inorganic pigment is not particularly limited, and for example, TiO ₂ , ZrO ₂ , ZrSiO ₄ , Cu—Cr—Mn, etc. can be used. As the glass material, B ₂ O ₃ —SiO ₂ type, Na ₂ O—CaO—SiO ₂ type, or the like can be used.
As a material of the heat resistant resin layer 8, a polyimide resin, a polyamide resin, a fluorine resin, a silicone resin, or a composite thereof can be used as a main component.

  The material of the adhesive is not particularly limited, and for example, an acrylic, epoxy, urethane, silicone, or modified silicone adhesive is used, which may be one-component or two-component. These adhesives can be used alone or in combination of two or more. Since it becomes high temperature during cooking, it is preferable to use a silicone-based adhesive from the viewpoint of heat resistance. Silicone adhesives include a reaction type such as a condensation reaction type and an addition reaction type, and a curing reaction condition includes a room temperature curing type and a heat curing type, and any type can be used.

  Examples of the material for the water-soluble polymer layer 9 include natural polymers, semi-synthetic polymers, synthetic polymers, and inorganic polymers. As the synthetic polymer, polyvinyl alcohol, polyethylene glycol, polypropylene glycol, polyacrylamide, pyroacrylic acid, polyvinyl pyrrolidone, water-soluble alkyd, polyvinyl ether, polymaleic acid copolymer, polyethylene imide, etc. are used. From the viewpoint of solubility, it is preferable to use polyvinyl alcohol, polyethylene glycol, polypropylene glycol, or polyvinyl ether.

  The method for forming the water-soluble polymer layer 9 on the heat-resistant resin layer 8 is not particularly limited as long as it is a method that can uniformly coat the water-soluble polymer coating liquid on the heat-resistant resin layer 8. Spray, brush, roller, sponge, etc. can be used. If the thickness of the water-soluble polymer layer 9 is too thin, the permeation preventive effect and stress relaxation effect of the low molecular components of the adhesive cannot be obtained, and if it is too thick, the adhesive strength to the heat-resistant resin layer 8 decreases, and the adhesive layer 10 generates a crack due to the stress generated in 10. When the concentration of the water-soluble polymer coating solution is less than 1%, the coating film thickness becomes thin. When the concentration exceeds 10%, the coating film thickness becomes too thick. In particular, it is more desirable to set it to 2% or more and 7% or less.

  In the IH cooking heater configured as described above, since the inorganic pigment layer 7 is coated on the back surface of the transparent crystallized glass 6, cooking such as a heater for induction heating disposed at the lower portion of the cooking pan mounting portion 3a. The internal structure of the vessel is not visible.

  A water-soluble polymer layer 9 is interposed between the heat-resistant resin layer 8 and the adhesive layer 10. The water-soluble polymer layer 9 is a dense film, and acts to relieve stress generated in the adhesive layer 10 while preventing the low-molecular component of the adhesive from permeating. Therefore, even if the heat-resistant resin layer 8 becomes a high temperature state during cooking and deteriorates and cracks are generated, it is possible that the low molecular component of the adhesive penetrates into the inorganic pigment layer 7 through the cracks of the heat-resistant resin layer 8. The occurrence of poor appearance is suppressed by the conductive polymer layer 9. Further, the stress generated in the adhesive layer 10 due to the curing shrinkage of the adhesive and the thermal stress generated in the adhesive layer 10 due to the temperature rise during cooking are alleviated by the water-soluble polymer layer 9. Therefore, the occurrence of cracks in the heat resistant resin layer 8 due to the stress generated in the adhesive layer 10 is suppressed. Accordingly, it is possible to suppress the occurrence of appearance defects in which crack portions inside the inorganic pigment layer 7 and the heat resistant resin layer 8 appear white as seen from the cooking surface side surface of the top plate 2.

In the above embodiment, the heat resistant resin layer is formed directly on the inorganic pigment layer, but a silica layer may be interposed between the inorganic pigment layer and the heat resistant resin layer.
Moreover, in the said embodiment, although demonstrated using an electromagnetic cooking appliance as a heating cooking appliance, even if it applies to another heating cooking appliances, such as a gas cooking appliance, there exists the same effect.

  Hereinafter, the present invention will be described specifically by way of examples.

Example 1.
A resin and an organic solvent were added to a frit obtained by mixing a commercially available Cu—Cr—Mn black inorganic pigment powder and B ₂ O ₃ —SiO ₂ glass powder (BHW manufactured by Nippon Electric Glass Co., Ltd.) at a mass ratio of 7: 3. The paste was prepared by adding. Next, this paste was applied to the entire back surface of 4 mm thick transparent crystallized glass 6 (Neoceram N-0 manufactured by Nippon Electric Glass Co., Ltd.), dried at 100 to 150 ° C. for 10 to 20 minutes, and then 30 minutes at 850 ° C. The inorganic pigment layer 7 as a light shielding layer was formed on the back surface of the transparent crystallized glass 6 by baking for a minute. Next, a silicone resin was applied to the entire surface of the inorganic pigment layer 7 and dried to form a heat resistant resin layer 8. Next, a 5% aqueous solution of polyvinyl alcohol (Gosefimer (Nippon Gosei Kagaku) Z-100) is brushed on the entire surface of the heat-resistant resin layer 8, and a silicone one-part moisture-curing adhesive is applied thereon. And bonded to the underframe 5 made of SUS430. The curing conditions of the adhesive were curing and curing for 7 days in an environment of 30 ° C. and 60% RH.

  The evaluation sample thus prepared was subjected to a high-temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6 (the side opposite to the inorganic pigment layer). No stain was observed in any of the evaluation samples after the high-temperature exposure test.

Example 2
An evaluation sample was prepared in the same manner as in Example 1 except that a 2% aqueous solution was used instead of the 5% aqueous solution of Goosefimmer (Nippon Synthetic Chemical Registration) Z-100).

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. No stain was observed in the evaluation sample.

Example 3
An evaluation sample was prepared in the same manner as in Example 1 except that a 7% aqueous solution was used instead of the 5% aqueous solution of Goosefimmer (Nippon Synthetic Chemical Registration) Z-100).

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. No stain was observed in the evaluation sample.

Example 4
An evaluation sample was prepared in the same manner as in Example 1, except that a 5% aqueous solution of polyvinyl pyrrolidone K15 (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of the 5% aqueous solution of Goosefimmer (Nippon Synthetic Chemical Registration Z-100) Produced.

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. No stain was observed in the evaluation sample.

Example 5 FIG.
An evaluation sample was prepared in the same manner as in Example 1 except that a silicone-based one-component thermosetting adhesive was used instead of the silicone-based one-component moisture-curable adhesive. The curing condition for the silicone-based one-component thermosetting adhesive was 120 ° C. for 1 hour.

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. No stain was observed in the evaluation sample.

Example 6
An evaluation sample was prepared in the same manner as in Example 4 except that a silicone-based one-component thermosetting adhesive was used instead of the silicone-based one-component moisture-curable adhesive. The curing condition for the silicone-based one-component thermosetting adhesive was 120 ° C. for 1 hour.

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. No stain was observed in the evaluation sample.

Comparative Example 1
An application sample of 5% aqueous solution of Goosefimmer (Nippon Synthetic Chemicals) Z-100 was omitted and an evaluation sample was prepared in the same manner as in Example 1.

  The evaluation sample thus prepared was subjected to a high temperature exposure test (155 ° C. 1500 hours, 200 ° C. 100 hours), and the adhesion region was visually observed from the surface side of the transparent crystallized glass 6. Staining was also observed in the evaluation sample.

  Thus, in Comparative Example 1 in which the water-soluble polymer layer 9 was not interposed between the heat-resistant resin layer 8 and the adhesive layer 10, the occurrence of stain was observed after the high-temperature exposure test. This is presumably because the stress generated in the adhesive layer 10 exposed to high temperature acts on the heat-resistant resin layer 8 without any relaxation, and cracks are generated in the heat-resistant resin layer 8. .

  On the other hand, in Example 1-6 in which the water-soluble polymer layer 9 was interposed between the heat-resistant resin layer 8 and the adhesive layer 10, no stain was observed after the high-temperature exposure test. This is presumably because the water-soluble polymer layer 9 relaxed the stress generated in the adhesive layer 10 exposed to a high temperature and suppressed the occurrence of cracks in the heat-resistant resin layer 8.

In each of the above examples, the adhesive is applied on the water-soluble polymer layer after the water-soluble polymer layer is applied on the heat-resistant resin layer. A drying step of the conductive polymer layer may be performed.
In each of the above embodiments, the adhesive is formed on the water-soluble polymer layer, but the adhesive may be formed on the underframe (frame) side.

  2 top plate, 4 frame, 5 under frame (frame), 6 transparent crystallized glass, 7 inorganic pigment layer (light shielding layer), 8 heat-resistant resin layer, 9 water-soluble polymer layer, 10 adhesive layer.

Claims (4)

A light-shielding layer is formed on the back surface of the flat transparent crystallized glass, and a heat-resistant resin layer is provided with a top plate formed on the light-shielding layer, and the top plate is bonded and fixed to the frame by an adhesive. Cooking utensils that have been
A cooking device characterized in that a water-soluble polymer layer is interposed between the heat-resistant resin layer and the adhesive layer.   The cooking device according to claim 1, wherein the water-soluble polymer layer is composed of polyvinyl alcohol or polyvinyl pyrrolidone.   The cooking device according to claim 1 or 2, wherein the adhesive is a silicone-based adhesive. It is a manufacturing method of the heating cooking appliance of any one of Claims 1 thru | or 3, Comprising:
Forming the light shielding layer on the back surface of the transparent crystallized glass;
Forming the heat-resistant resin layer on the light shielding layer;
Forming the water-soluble polymer layer on the heat-resistant resin layer;
Applying an adhesive to the water-soluble polymer layer or the frame, and bonding and fixing the top plate to the frame,
The step of forming the water-soluble polymer layer on the heat-resistant resin layer comprises applying a 1 to 10% aqueous solution of the water-soluble polymer on the heat-resistant resin layer. .

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