JPH0249611A - Vessel for cooking food with microwave oven - Google Patents

Abstract

PURPOSE:To radiate far infrared rays and set the appearance, eating feeling, taste, and the like of foods to be the best ones by arranging an internal layer including the radiating body of the far infrared rays, and an external layer compounded of or mixed with substance for absorbing a microwave and generating heat. CONSTITUTION:In a synthetic resin film or sheet, the powders or grains of a far infrared ray radiating body (a) are mixed, and an internal layer 1 including the far infrared ray radiating body (a) is formed. As substance (b) for absorbing a microwave and generating heat, a proper one is selected from generally well- known materials and should be used, but for example, the thin films of a metallic element and a metallic oxide are laminated on the plastics films of polyester, polyethylene, polypropylene, nylon, cellophane, polysulfone, and the like by an evaporating method, and the complex of the heat generating substance (b) is formed, or between the internal layer 1 and external layer 2 of a vessel, another layer is set as an intermediate layer, and the heat generating substance (b) consisting of mixtures with inorganic salt dispersed and mixed in the intermediate layer through the medium of paste-like or gel-like substance is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION A1.Object of the invention (industrial application field) The present invention is a food container for microwave cooking. More specifically, it relates to a container that efficiently heats the food contained therein using far infrared rays.

(Prior art) In recent years, food preparation using a microwave oven has become fast and
It is widely used for household use due to its hygienic properties, and is widely used for heating cold rice, warming sake, thawing and heating cooked foods, and cooking raw foods. Glass, ceramic, and plastic materials are used. Therefore, when cooking raw food by placing it on top of these containers, the food is heated by microwaves, which remove the water molecules contained in the food by friction, unlike heating by heat transfer from firewood, charcoal, gas, electric heat, etc. Since this method generates heat by heating the food, the surface temperature is lower than that of the heat conduction method, and there is no difference in temperature between the inside and the inside, so the food has the appearance, texture, and taste of raw food. , the surface of the baked goods will not get browned,
The quality of cooked foods is significantly inferior to that prepared using heat conduction methods, such as sweet potatoes lacking sweetness and grilled meat not being tender.

Therefore, some cooking containers have been devised to have a microwave absorbing heating element installed on the inner wall of the cooking container and transfer the heat generated from this to the food through thermal conduction to brown the food. It takes time, and it is also difficult to mark the food with burnt dates, as will be described later, and is of little use in improving texture and taste.

(Problem to be Solved by the Invention) When reheating cooked food such as tempura, fried food, stir-fried food, etc. using the cooking container described above, when placed in the microwave, fats and oils from the food rise to the surface and become sticky. Moreover, if the heating time is prolonged, the moisture on the outside will be rapidly lost, resulting in a hard and dry state, which will not provide a crisp texture and will have a bad taste.

Raw foods 1. For example, raw fish, raw meat, and gratin.

When cooking pizza, dumplings, etc., in order to make the surface brown, it is difficult to adjust the temperature of the heating element in containers with a heating element on the surface, and differences in food type, shape, weight, etc. The texture is uneven, making it difficult to get just the right degree of grilling; overcooking can result in only the surface becoming burnt, or undercooking can result in insufficient browning.

Most of the heating elements described above are only effective at coloring the surface of foods, and cannot be expected to improve the texture and taste of foods.

It had the following problems.

The present invention has been made in order to solve the above-mentioned conventional problems, and is designed to optimize the appearance, texture, taste, etc. of food by emitting far-infrared rays when heating food using a microwave oven. The purpose of the present invention is to provide a food container for cooking in a microwave oven.

1. Structure of the Invention (Means for Solving the Problems) The means of the present invention to achieve the above object is to provide a food container used for microwave cooking of food with an inner layer containing a far-infrared radiator. The outer layer is composed of or mixed with a substance that absorbs microwaves and generates heat.

In this food container, as shown in FIGS. 1 to 4, the inner layer 1 containing the far-infrared radiator a emits far-infrared rays to the food when the food is cooked in a microwave oven.

This far-infrared rays do not perform heating by thermal conduction, but instead use electromagnetic waves, that is, hot-ray heating, so heat transfer to the inside of the food is very efficient and rapid, and it does not use conventional heating elements. Even if the surface becomes carbonized due to overheating, as with browning, there is no need to worry about the inside being undercooked.The whole food is heated evenly, and the food after cooking has a crispy texture. It has a good texture and an excellent flavor.

The radiation intensity of this far infrared ray is expressed by the following formula.

Eb=σT'(W/cJ> (Stefan-Bormann equation) Eb: Total radiant energy of an ideal blackbody σ: Stefan-Borman constant T: Absolute temperature Em= e E b (W/a(> Em: Real substance Total radiant energy ε: Emissivity of real substance (0〈〈〈〈〈〈〈〈〈〈〈〈〈〈〈〈〉) From the above equation, the far-infrared radiation intensity of an object increases as the absolute temperature of the object increases. Therefore, the far-infrared radiator of the container of the present invention is The higher the temperature, the more effective it will be.

However, far-infrared radiators do not normally absorb microwaves and generate heat, so the far-infrared radiation intensity is weak and the irradiation effect on food cannot be obtained.
In this container, C is the inner layer 1 containing the far-infrared radiator.
The outer layer 2 is composed of a material that absorbs microwaves and generates heat, either compositely as shown in Figure 1 or mixed as shown in Figure 2.
Since the exothermic substance and the far-infrared ray emitter a are integrated by placing them adjacent to each other, the far-infrared ray emitter a becomes hot in a short time and irradiates the food with high-intensity far-infrared rays.

The inner layer 1 containing the far-infrared emitter a used in the container of the present invention is made of polyolefin such as polyethylene, polypropylene, ethylene vinyl acetate copolymer, polyester, polyamide, polystyrene, polycarbonate, polyvinylidene chloride,
It is made of a synthetic resin film or sheet of thermoplastic resin such as polyacrylonitrile, thermosetting resin such as phenol resin, epoxy resin, melamine resin, etc., and has a suitable thickness of 10 to 100 μm.

Powder or particles of the far-infrared radiator a are mixed into the synthetic resin film or sheet to form the inner layer 1 containing the far-infrared radiator a.

The powder or particles of this far infrared radiator a have a wavelength of 1 to 10
Any material that mainly emits far infrared rays of 00 μm can be used. For example, it is made of a mixture of metal oxides, metal carbides, silicon nitride zirconia ceramics, and the like. These far-infrared radiator powders or particles are usually dispersed and mixed in a synthetic resin film or sheet in an amount of 1 to 60% by weight. If the content is below this range, the amount of far-infrared radiation will be insufficient, and if it is above this range, it will be difficult to form a synthetic resin film or sheet.

As the substance that absorbs microwaves and generates heat to be used in the container of the present invention, any suitable material may be selected from those generally widely known. For example, thin films of metal elements, metal oxides, It can be laminated to a plastic film such as polyester, polyethylene, polypropylene, nylon, cellophane, polysulfone, etc. by vapor deposition to form a composite of the exothermic substance, or it can be used as an intermediate layer between the inner layer 1 and the outer layer 2 of the container. The exothermic substance is made of a mixture in which an inorganic salt is dispersed and mixed using a paste-like or gel-like substance as a medium.

Since this intermediate layer is a fluid, the inner layer 1 and the outer layer 2 are adhered in advance by heat welding or the like at the flange portion of the container, as shown in FIG. 2, to confine the exothermic substance.

In this case, the inner layer 1 is a layer containing the far-infrared radiator a, and is suitably made of a thermoplastic resin that is easily heat-welded. Also, outer layer 2
Uses the same material as the thermoplastic resin used for the inner layer 1, or a material that can be thermally welded thereto. The paste or gel-like substance into which the inorganic salt is mixed is preferably one that is stable to heat and has a boiling point of at least 250°C or higher. For example, the paste may be glycerin, and the gel substance may be silicone gel. The amount of inorganic salt mixed is preferably 1 to 20% by weight. Outside this range, if it is less than 1%, no heat generating effect can be obtained, and if it is more than 20%, dispersion is difficult.

Furthermore, an inner layer 1 containing a far-infrared radiator a, and an outer layer 2 that is a composite or mixture of a substance that absorbs microwaves and generates heat.
This means that it can be attached, affixed, etc. to the inside of a general-purpose microwave food container 3 as shown in FIG. If it is stopped, the general-purpose food container 3 can be used as a far-infrared heating container.

(Example) (1) 5% particles of 70% zirconium and 30% clay sintered at 1300°C are mixed into polypropylene,
A 200 μm sheet was obtained using a T-die extrusion device. Indium tin oxide was vapor-deposited onto a polypropylene sheet to a thickness such that the surface resistance value was 200Ω/hole. The above two sheets were bonded and composited using a dry lamination method with the vapor-deposited surface facing inside.

This composite sheet is molded with the layer containing the far-infrared emitter inside to form a container.

(2) Mix 5% of particles made by sintering 70% zirconium and 30% clay at 1300°C into polypropylene,
A 200 μm sheet was obtained using a T-die extrusion device. A composite sheet in which 10% sodium chloride is dispersed in a silicone gel material, formed into a 500 μm sheet, placed between 200 μm polypropylene and the sheet containing the above-mentioned far-infrared radiator, and thermally bonded on all sides to confine a heat generating layer. do. This composite sheet was molded with the layer containing the far-infrared radiator inside to form a container.

(3) A container was formed by molding a polypropylene single sheet of 400 μm.

(4) Indium tin oxide was deposited on a 400 μm polypropylene sheet to a thickness such that the surface resistance value was 200 Ω/hole. The vapor-deposited layer of this sheet was molded to form a container.

Using each of the molded containers shown in Examples 1 to 4, about 75 g of raw potatoes and 30 g of cooked shrimp were cooled in the refrigerator, then heated in a 500 W microwave for 4 minutes and 1 minute, respectively. -I tasted it.

The results are shown in the attached table.

(Effects of the Invention) In the microwave cooking food container of the present invention, the composite or mixed material of the outer layer absorbs microwaves and generates heat, heats the far-infrared radiator of the inner layer, and emits high-intensity far-infrared rays. The food inside is heated by far infrared rays, which eliminates all the defects caused by microwave cooking, making it possible to efficiently prepare cooked products with excellent appearance, texture, and taste.

If an inner layer that contains a far-infrared radiator and an outer layer that is a composite or mixture of a substance that absorbs microwaves and generates heat are attached to a general-purpose food container for microwave ovens, and the pasting is the same, Food can be cooked using far-infrared rays using a general-purpose container.

When a heat-sealable thermoplastic resin is used as the inner layer portion containing the infrared radiator, a bag-shaped food package for microwave cooking such as a four-sided seal bag, a wax bag, and a gusset bag can be obtained.

If you use an insulating material such as a foam sheet for the inner layer and make the container insulated, you can heat cooked food or hot sake and then keep it warm so that it does not cool down and you can eat or drink it comfortably. I can do it.

It has the following unique effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of a food container according to the present invention. FIG. 2 is a longitudinal sectional side view showing another embodiment. FIG. 3 is a longitudinal sectional side view showing still another embodiment. FIG. 4 is a longitudinal sectional side view showing an embodiment in combination with a general-purpose container. 1: Inner layer a: Far-infrared radiator 2: Outer layer b; Substance that absorbs microwaves and generates heat 3: General-purpose food container 1st broom diagram

Claims (1)

[Claims] A food container for cooking in a microwave oven, comprising an inner layer containing a far-infrared radiator and an outer layer composed of or mixed with a substance that absorbs microwaves and generates heat.