JP6552213B2 - Microwave cooking container - Google Patents

Description

  The present invention relates to a container for microwave cooking.

  In recent years, the composition of each household has decreased, and the number of seniors has increased. As a result, in the field of food, a small amount of food is needed for one meal, and there are many occasions where a microwave oven is used. For example, in each household, it is a common practice to heat up the necessary amount of prepared food in a microwave oven. The grocery store sells prepared foods for small households, and a microwave oven is installed in the store to warm it. Furthermore, a product has been developed in which food for a small number of people is stored in a container and can be cooked as it is using a microwave oven.

  About the container which can cook using a microwave oven in the state which accommodated foodstuffs, it is a paper container for heating cooking using a microwave oven to patent document 1, Comprising: The window which can visually recognize the condition of foodstuffs It is disclosed that the part is provided on the upper surface. Further, Patent Document 2 describes a paper container for baking or steaming using a microwave oven, in which the surface of a sheet-like substrate of thick paper is placed on the surface of a sheet-like substrate of a thick paper in a tray-like container body. There is disclosed one in which a heating element provided with a metal deposition film that generates heat by waves is disposed.

JP, 2013-184718, A JP, 2013-129435, A

  By the way, when baking and cooking, it is desirable to visually check the degree of burning of the foodstuffs widely during cooking. However, with the paper containers disclosed in Patent Literatures 1 and 2, when performing baking using a microwave oven, the state of the food can be visually confirmed only from above, so the range where the degree of burning can be visually confirmed is narrow. In addition to that, it is possible to visually confirm the degree of burning of the food in the container outside the microwave before and after cooking, but also visually checking the degree of burning of the food in the container placed in the microwave during cooking There is a problem that is difficult.

  It is an object of the present invention to be able to visually check the degree of burning of a food in a wide range even during cooking when performing baking using a microwave, and to suppress the container body from being damaged by the heat of baking. It is to provide a container for cooking a microwave oven.

  According to the present invention, a transparent container main body formed of a thermoplastic resin and opened upward, a heat generating film provided at the bottom of the container main body and generating heat by microwaves of a microwave oven, the container main body and the heat generating film And a thermal insulation sheet provided between the two.

  According to the present invention, since the transparent container main body opened upward is formed of a thermoplastic resin, when baking is performed using a microwave oven, the degree of burning of the food is wide even from the upper side and the side even during cooking. In addition, since the heat insulating sheet is provided between the container body and the heat generating film, the container body can be prevented from being damaged by the heat of baking.

It is a perspective view which shows the state which closed the lid | cover of the container for microwave ovens which concerns on embodiment. It is a perspective view showing the state where the lid of the container for microwave oven cooking concerning an embodiment was opened. It is an exploded perspective view of a container for microwave oven cooking concerning an embodiment. It is a longitudinal cross-sectional view of the container for microwave oven cooking which concerns on embodiment. It is a perspective view of a heat generating sheet and a heat insulation sheet. It is sectional drawing of a heat-generating sheet and a heat insulation sheet. It is sectional drawing of a heat-generating sheet. FIG. 1 is a perspective view of a food pack of a container for microwave oven cooking of Example 1; It is the (a) top view and the (b) side view of the container main part of the food pack of the container for microwave oven cooking of Example 2, and the resin container which constitutes the lid.

  Hereinafter, the embodiment will be described in detail.

  1 to 4 show a microwave oven cooking container 10 according to an embodiment. The container 10 for microwave oven cooking which concerns on this embodiment can be used suitably for baking cooking of the foodstuff F by a microwave oven.

  The microwave oven cooking container 10 according to the embodiment includes a transparent container main body 11 opened upward and a lid 12 for closing the opening, and the container main body 11 and the lid 12 are integrally formed to be a food pack P is configured. A heat generating sheet 13 is provided at the bottom of the container main body 11, and a heat insulating sheet 14 is provided between the container main body 11 and the heat generating sheet 13.

  The container body 11 is formed in a shallow bottom tray shape having a rectangular plan view. The container body 11 is preferably formed of a transparent thermoplastic resin from the viewpoint of achieving transparency. The transparency of the thermoplastic resin can be evaluated by cutting a part of the thermoplastic resin sheet material before molding the container and measuring the haze value as an index of transparency. It shows that it is excellent in transparency, so that the value of a haze value is small. The haze value of the thermoplastic resin is preferably 30% or less, more preferably 30% or less, from the viewpoint of being able to visually check the degree of burning of the food material F from above and from sideways even during cooking when baking using a microwave It is 20 or less, more preferably 15% or less, and from the viewpoint of obtaining heat resistance, it is preferably 0.5% or more, more preferably 3% or more, and further preferably 5% or more. The haze value of this thermoplastic resin can be measured based on JIS K7105 using an integrating sphere type light transmittance measuring device.

  Examples of the thermoplastic resin that forms the container body 11 include thermoplastic resins having heat resistance and transparency. For example, polylactic acid resin (hereinafter referred to as “PLA”) and polyethylene terephthalate resin (hereinafter referred to as “PET”). And polyester resins such as polypropylene terephthalate resin (hereinafter referred to as “PPT”), polybutylene terephthalate resin (hereinafter referred to as “PBT”), polypropylene resin, polybutylene succinate resin, and the like. The thermoplastic resin may be composed of only a single species or may be composed of a plurality of blend resins. The thermoplastic resin preferably has crystallinity from the viewpoint of moldability and heat resistance. The thermoplastic resin preferably includes a crystalline polyester resin, more preferably includes PLA, and more preferably includes two or more blend resins of PET, PPT, and PBT, and includes only PLA. And, it is more preferable to include only a blend resin of PET and PBT.

  As PLA of a thermoplastic resin, polylactic acid obtained by condensation polymerization of only a lactic acid component as a monomer, and condensation polymerization of a lactic acid component and a hydroxycarboxylic acid component other than lactic acid (hereinafter referred to as "hydroxycarboxylic acid component") as a monomer. And copolymerized polylactic acid. The PLA of the thermoplastic resin may be composed of only one of these, or may be composed of both of them.

  As lactic acid components in PLA, optical isomers of L-lactic acid (L-form) and D-lactic acid (D-form) are present. From the viewpoint of heat resistance, PLA as the thermoplastic resin preferably has a high L-form content as a lactic acid component, and therefore, a low D-form content. Specifically, the L-form content of the lactic acid component in PLA is preferably 95 mol% or more, more preferably 98.7 mol% or more, and further preferably 99.5 mol% or more. The D-form content of the lactic acid component in PLA is preferably 5 mol% or less, more preferably 1.3 mol% or less, and still more preferably 0.5 mol% or less. The L-form and D-form contents of the lactic acid component in PLA are described in “Voluntary Standards for Food Containers and Packaging Made of Synthetic Resins such as Polyolefins, Third Edition, Revised June 2004, Part 3, Sanitation Test Method P12-13” It can obtain | require based on the measuring method of L body and D body content.

  Examples of the hydroxycarboxylic acid component in the PLA of the copolymer include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, and the like. The hydroxycarboxylic acid component in the PLA of the copolymer may be composed of a single species or a plurality of species.

  The PLA content in the thermoplastic resin is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass from the viewpoints of heat resistance and transparency.

  Moreover, when a thermoplastic resin contains PLA, it is preferable that the crystal nucleus agent is added to the thermoplastic resin from a heat resistant and transparent viewpoint. The crystal nucleating agent used at this time is preferably an organic crystal nucleating agent, more preferably an amide-based organic crystal nucleating agent, from the viewpoint of heat resistance and transparency.

  The amide organic crystal nucleating agent is not particularly limited as long as it is a compound having one or more amide bonds, and a compound having a hydroxyl group and / or an ester group in addition to the amide bond is preferably used. Such compounds include, for example, fatty acid monoamides and fatty acid bisamides. The amide organic crystal nucleating agent used at this time is preferably one or more selected from fatty acid monoamides and fatty acid bisamides, more preferably fatty acid bisamides, from the viewpoints of heat resistance, transparency, and crystallization rate. is there.

  The carbon number of the fatty acid in the fatty acid monoamide and fatty acid bisamide is preferably 8 or more, more preferably 12 or more, still more preferably 16 or more, from the viewpoint of heat resistance, transparency, and crystallization rate, and preferably 24 Below, more preferably 22 or less, still more preferably 20 or less.

  Specific examples of the fatty acid bisamide include methylene bis 12-hydroxystearic acid amide, ethylene bis 12-hydroxystearic acid amide, hexamethylene bis 12-hydroxystearic acid amide, xylylene bis 12-hydroxystearic acid amide, ethylene bisstearin Acid amide, ethylene bis oleic acid amide, ethylene bis lauric acid amide, etc. are mentioned.

  The addition amount of the crystal nucleating agent is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably from 100 parts by mass of PLA from the viewpoint of heat resistance, transparency, and crystallization speed. Is 0.2 parts by mass or more, and from the viewpoint of transparency, it is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and still more preferably 0.7 parts by mass or less.

  When the thermoplastic resin contains two or more blend resins of PET, PPT, and PBT, the content of the two or more blend resins of PET, PPT, and PBT in the thermoplastic resin is heat resistance and transparency. From the viewpoint of the properties, it is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass.

  When the thermoplastic resin contains a blend resin of PET and PBT, the blend resin of PET and PBT of the thermoplastic resin is a blend mass ratio of PET and PBT (PET / PBT) from the viewpoint of heat resistance, transparency, and crystallization rate. PBT) is preferably 10/90 or more, more preferably 20/80 or more, still more preferably 30/70 or more, and preferably 90/10 or less, more preferably 80/20 or less, still more preferably 70 / It is 30 or less, still more preferably 50/50 or less.

  The melting point of the thermoplastic resin is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 150 ° C. or higher, from the viewpoint of heat resistance, and preferably 260 ° C. or lower, from the viewpoint of moldability. Preferably it is 230 degrees C or less, More preferably, it is 200 degrees C or less. In addition, melting | fusing point of a thermoplastic resin can be measured from the crystal melting endothermic peak temperature by the temperature rising method of differential scanning calorimetry (DSC) based on JISK7121.

  A plasticizer, a hydrolysis inhibitor and the like may be added to the thermoplastic resin forming the container body 11.

  As a plasticizer, for example, an ester of a polyvalent carboxylic acid and a monoalcohol or its (poly) oxyalkylene adduct, and the like can be mentioned. The addition amount of the plasticizer is preferably 0.01 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 1 part by mass or more with respect to 100 parts by mass of the thermoplastic resin from the viewpoint of transparency. Also, from the viewpoint of transparency and crystallization rate, it is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less.

  As the hydrolysis inhibitor, a carbodiimide compound such as a polycarbodiimide compound or a monocarbodiimide compound is preferably used from the viewpoint of inhibiting hydrolysis. The addition amount of the hydrolysis inhibitor is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.1 parts by mass with respect to 100 parts by mass of the thermoplastic resin from the viewpoint of inhibiting hydrolysis. The amount is 15 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 1 part by mass or less from the viewpoint of transparency.

  The lid 12 is formed in a tray shape having a shallower bottom than the rectangular container body 11 which is substantially the same as the container body 11 in plan view. The lid 12 is formed of the same transparent thermoplastic resin as the container body 11.

  The container body 11 and the lid 12 are connected to each other through one hinge 15 at one long side of their open ends, and the openings are opposed to each other so as to be opened and closed. . The open end of the container body 11 and the lid 12 may be configured to be able to form an engagement structure so as to be sealable.

  The haze value, which is an indicator of the transparency of the food pack P constituted by the container body 11 and the lid 12, is preferably 30% or less, from the viewpoint of visually confirming the burning condition of the food material F from above and from a wide range even during cooking. More preferably, it is 20% or less, more preferably 15% or less, and from the viewpoint of obtaining heat resistance, it is preferably 0.5% or more, more preferably 3% or more, and further preferably 5% or more. The haze value of the food pack P can be measured by cutting a part of a flat portion of the container and using an integrating sphere light transmittance measuring device based on JIS K7105.

  The food pack P composed of the container body 11 and the lid 12 is warped or dented preferably at an evaluation temperature of 130 ° C., more preferably at an evaluation temperature of 150 ° C., in the heat resistance test specified in JIS S2029: 2002. Preferably not.

  The food pack P constituted by the container body 11 and the lid 12 can be manufactured by thermoforming such as vacuum forming, pressure forming, double-sided vacuum forming, hot plate forming or the like using a resin sheet material of a transparent thermoplastic resin . The resin sheet material can be produced, for example, by extrusion molding using a single screw extruder or a twin screw extruder. The thickness of the resin sheet material is preferably 0.1 mm or more, more preferably 0.15 mm or more, and still more preferably 0.2 mm or more, from the viewpoints of heat resistance and moldability. From the viewpoint, it is preferably 1.5 mm or less, more preferably 0.8 mm or less, and still more preferably 0.5 mm or less. The resin sheet material may have transparency without being stretched from the viewpoint of reducing the equipment load and process load of the stretching process, and from the viewpoint that the shapeability in thermoforming, that is, a complex shape can be formed. preferable.

  5 and 6 show the heat generating sheet 13 and the heat insulating sheet 14. FIG. 7 shows the heat generating sheet 13.

  The heat-generating sheet 13 has a sheet-like base 13a, a heat-generating film 13b laminated thereon, and a covering film 13c laminated thereon. The thickness of the heat generating sheet 13 is, for example, 0.05 to 0.5 mm.

  Examples of the substrate 13a include paper excellent in heat resistance, and resin films such as polyester resin and polyamide resin. The thickness of the base 13a is, for example, 0.005 to 0.25 mm.

  Examples of the heat generating film 13b include a metal film such as aluminum or nickel that generates eddy currents by microwaves from a microwave oven and generates heat due to Joule heat of its electric resistance. The thickness of the heat generating film 13b is, for example, 20 to 100 mm.

  As covering film 13c, resin films, such as polyester resin which is excellent in heat resistance, and a polyamide resin, are mentioned, for example. The thickness of the covering film 13c is, for example, 0.005 to 0.25 mm.

  The heat generating sheet 13 forms a heat generating film 13b by vapor deposition of a metal such as aluminum on the base material 13a or coating of a coating agent in which a metal filler such as aluminum is dispersed in a binder resin, and the heat generating film 13b side is covered with a coating film. The heat generating film 13b is formed by vapor deposition or coating on the covering film 13c by covering with 13c and adhering or fusing, so that the heat generating film 13b is on the base 13a side. It can be manufactured by adhesion or fusion.

  Examples of the heat insulating sheet 14 include paper excellent in heat resistance, and resin sheets such as polyester resin and polyamide resin. The thickness of the heat insulating sheet 14 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and still more preferably 0.5 mm or more, from the viewpoint of suppressing the container body 11 from being damaged by the heat of baking cooking. Also, from the viewpoint of economy, it is preferably 3 mm or less, more preferably 2 mm or less, and still more preferably 1.0 mm or less.

  The heat generating sheet 13 and the heat insulating sheet 14 are formed in a rectangular shape corresponding to the shape of the bottom of the container body 11. The heat generating sheet 13 is laminated on the heat insulating sheet 14 so that the base 13 a is on the heat insulating sheet 14 side. From the viewpoint of preventing the heat effect of the heat generating sheet 13 from reaching the container body 11, the heat generating sheet 13, and hence the heat generating film 13 b, is formed smaller than the heat insulating sheet 14, and the heat generating film 13 b is formed on the heat insulating sheet 14. It is preferable that the heat insulating sheet 14 be provided so as to protrude from the outer periphery of the sheet and be bonded to the heat insulating sheet 14 via a heat-resistant adhesive. The protrusion width of the heat insulating sheet 14 is preferably 0.5 mm or more, more preferably 1 mm or more, further preferably 2 mm or more, and from the viewpoint of economy, it is preferably 10 mm or less, more preferably 5 mm or less, still more preferably. Is 3 mm or less. The heat insulating sheet 14 may be bonded to the bottom of the container body 11 via a heat resistant adhesive.

  In the baking using the microwave cooking container 10 according to the embodiment, first, after the food F is placed on the heat generating sheet 13 provided on the bottom of the container body 11 via the heat insulating sheet 14 and the lid 12 is closed. In a microwave oven, microwaves are irradiated for a predetermined output and for a predetermined time. Examples of the food F include raw fish, raw meat, raw vegetables and the like. The microwave output of the microwave oven is 400 to 2000 W, for example, and the irradiation time is 10 to 300 seconds, for example, depending on the type and amount of the food F.

  According to the microwave cooking container 10 according to the embodiment having the above-described configuration, the food pack P including the container body 11 and the lid 12 that are opened upward is formed of a transparent thermoplastic resin. In the case of baking using the above, the degree of burning of the food material F can be visually checked in a wide range from above and from side to side even during cooking, and heat insulation between the container body 11 and the heat generating sheet 13 including the heat generating film 13b Since the sheet | seat 14 is provided, it can suppress that the food pack P comprised with the container main body 11 and the lid | cover 12 is damaged with the heat | fever of baking cooking. Moreover, in the state which accommodated the foodstuff F in the container 10 for microwave cooking which concerns on embodiment, it can sell in a grocery store, and in this case, since the foodstuff F can be seen well from the outside of a container, a customer is the foodstuff in a container F can be sufficiently confirmed, and after purchase, cooking can be performed in the store or at home without touching the food F at all using a microwave oven. Furthermore, if the food pack P composed of the container main body 11 and the lid 12 is made of PLA, the PLA has biodegradability, so that it can be discarded as ordinary garbage after use.

  In the said embodiment, although it was set as the food pack P with which the container main body 11 and the lid | cover 12 were integrally comprised, it is not specifically limited to this, A container main body and a lid may be separately comprised. In this case, the lid may be formed of the same thermoplastic resin as the container body or may be formed of a different transparent material.

  In the said embodiment, although it was set as the structure by which the heat generating sheet 13 which has the heat generating film 13b was provided on the heat insulation sheet 14, it is not limited to this in particular, The heat generating film is directly vapor-deposited etc. on the heat insulating sheet. It is also good.

(Test evaluation method)
Example 1
Thermoplastic resin PLA (Natureworks LLC product name: Ingeo Biopolymer 2500HP, D-form content: 0.3 mol%, melting point: 165 to 50) in a twin-screw extruder (Ikegai Iron Works, model number: PCM-45) 180 ° C.) and, based on 100 parts by mass of this thermoplastic resin, 1.6 parts by mass of a plasticizer tributyl acetyl citrate (made by Taoka Chemical Industry Co., Ltd.) and 0.5 parts by mass of a crystal nucleating agent of ethylene A bis (stearic acid amide) (manufactured by Nippon Kasei Chemical Co., Ltd., trade name: Suripax E) was charged, and the mixture was melt-kneaded, and the extruded molded product was strand cut to obtain PLA pellets. The kneading conditions were a rotational speed of 100 rpm and a melt-kneading temperature of 190.degree. Then, the obtained PLA pellets were dried in a reduced-pressure atmosphere at 70 ° C. for 1 day, and the water content was reduced to 500 ppm or less.

  The pellet of the dried PLA is charged into a single-layer sheet extruder (Model: BNT-32, manufactured by Plastic Engineering Research Institute Co., Ltd.) equipped with a cooling roll and a heating roll, and the mixture is melt-kneaded and 40 cm wide by extrusion. A transparent resin sheet material having a thickness of 0.3 mm was obtained. Molding conditions are: cylinder temperature of biaxial kneading part: 200 ° C., die (outlet) temperature: 190 ° C., winding speed (take-off speed): 2 m / min, cooling roll temperature: 20 ° C., and resin after contact with cooling roll The temperature of the sheet material was 25 to 30 ° C. The cylinder temperature of the twin-screw kneading section, the die (outlet) temperature, and the temperature of the resin sheet material after contact with the cooling roll were measured using a contact-type thermometer. The obtained resin sheet material was not subjected to uniaxial or biaxial stretching. Moreover, the haze value of the obtained resin sheet material was 13%.

  The resin sheet material obtained above is attached to the guide of a single-shot vacuum pressure forming machine (manufactured by Wakisaka Engineering Co., Ltd., model number: FVS-500P WAKITEC), and container body 11 of the same type as the above embodiment as shown in FIG. And a lid 12 having a length of 16.5 cm, a width of 10.0 cm, and a thickness of 3.6 cm were obtained. The haze value of the obtained food pack P was 13%. The molding conditions were preheating heater temperature: 400 ° C., preheating time: 5.5 seconds, temperature of the resin sheet material after preheating: 80 ° C., mold temperature: 100 ° C., and mold holding time: 12 seconds. After shaping, the mold was removed by air cooling. The temperature of the resin sheet material after preheating was measured directly using a surface thermometer.

  An aluminum heating film deposited on a polyester resin coated film is attached to a thin paper substrate so that the heating film is on the substrate side, with a length of 12.5 cm, a width of 6.0 cm, and a thickness of 0. A .07 mm heat generating sheet (manufactured by Toppan Printing Co., Ltd., trade name: susceptor) was prepared. Moreover, the heat insulation sheet of 13.0 cm in length, width 6.5 cm, and thickness 0.8 mm was prepared. The heat generation sheet (heat generation film) is provided at the center of the heat insulation sheet so that the heat insulation sheet protrudes about 2.5 mm from the outer circumference and the substrate is on the heat insulation sheet side, and bonded to the heat insulation sheet via a heat resistant adhesive. did. And this heat generating sheet and heat-resistant sheet were provided in the bottom part in the container main body of the said food pack so that a heat generating sheet might face upwards, and the container for microwave oven cooking was comprised.

  On a heat-generating sheet provided on the bottom of the container body of the above-described microwave oven cooking container, 30 g of fresh salted mackerel fillets were placed with the skin on the heat-generating sheet side, and the lid was closed. And put the container for microwave oven cooking which stored the raw salt mackerel in the inside to the microwave oven (Panasonic company make model number: NE-1801), the output of the microwave is 600W and irradiation time 80 seconds (2.67 seconds per 1 g) ) Baked salt mackerel.

  The following test evaluation was performed about the grill cooking of the salt mackerel in the microwave oven which used the above containers for microwave oven cooking.

  It was evaluated as “A” and “No” as “B” whether or not the baking degree of the salt mackerel could be visually confirmed in a wide range from above and from the side during cooking in the microwave oven.

  The degree of baking on the skin side of the salt mackerel after cooking was evaluated as A and “not fragrant” as B, depending on the presence or absence of flavor after cooking.

  The presence or absence of the deformation of the food pack of the container for microwave cooking after cooking was evaluated as “no deformation” as “A” and “deformed” as “B”.

  The presence / absence of melting (perforated) of the food pack of the microwave cooking container after cooking was evaluated as A without melting and B with melting.

Example 2
A kneader (made by Toyo Seiki Co., Ltd., trade name: Labo Plastomill), a PET sheet (made by Teijin, trade name: A-PET resin sheet, grade FR, melting point: 254 ° C.) cut into pellets Pellets of (Polyplastics Co., Ltd. trade name: DURANEX PBT 700FP EF 201 R, melting point: 223 ° C.) are charged so that the blend mass ratio of PET / PBT becomes 40/60 and melt-kneaded to make uniform PET and PBT The blend resin of The melting point of the obtained blend resin was 220 ° C. The kneading conditions were a rotation speed of 50 rpm, a melt kneading temperature of 230 ° C., and a kneading time of 10 minutes.

On a 0.5 mm thick stainless steel plate (ASANUMA & CO. LTD product name: Ferrotype Plate Deluxe), a spacer with a peripheral width of 2 cm and a thickness of 300 μm with a square space of 20 cm on a side is placed Then, a predetermined amount of the blended resin was cut into a pellet shape inside the spacer, and the same stainless steel plate was placed thereon. Then, it was set in a press machine (trade name: Lab Press manufactured by Toyo Seiki Co., Ltd.), and a transparent resin sheet material was obtained by press molding. The molding conditions, 5 minutes at a temperature 280 ° C. and a pressure of 5Kg / cm ^2, 5 min at a temperature 280 ° C. and a pressure of 200 Kg / cm ^2, and at a temperature 15 ℃ and pressure of 5Kg / cm ² was in the order of 1 minute. The obtained resin sheet material was not subjected to uniaxial or biaxial stretching. Moreover, the haze value of the obtained resin sheet material was 11%.

  By bending the obtained resin sheet material, as shown in FIG. 9, the bottom is a square with a side of 10 cm, the opening is a square with a side of 18.5 cm, and the height is 4.2 cm. A pair of resin containers having a shape in which the inner diameter is enlarged so that the side surfaces sink inward are made. And the food pack P was comprised by making the container main body 11 and the other the lid | cover 12 by these pair of resin containers, and opening each other butting. The haze value of the obtained food pack P was 11%.

  A square heat generating sheet having a side of 9.5 cm and a thickness of 0.07 mm, in which an aluminum heat generating film is vapor-deposited on a polyester resin coating film, is bonded to a thin paper base so that the heat generating film faces the base. (Susceptor, manufactured by Toppan Printing Co., Ltd.) was prepared. In addition, a square cardboard insulation sheet having a side of 10.0 cm and a thickness of 0.8 mm was prepared. The heat generation sheet (heat generation film) is provided at the center of the heat insulation sheet so that the heat insulation sheet protrudes about 2.5 mm from the outer circumference and the substrate is on the heat insulation sheet side, and bonded to the heat insulation sheet via a heat resistant adhesive. did. And this heat generating sheet and heat-resistant sheet were provided in the bottom part of one resin container which is the container main body 11 of the said food pack P so that a heat generating sheet might face upward.

  After placing 30 g of raw salt mackerel fillet on the heat generating sheet provided at the bottom of one resin container as the container main body 11 so that the skin is on the heat generating sheet side, the lid 12 of the food pack P is used. A certain other resin container is covered so that the openings are butted, and their edges are sealed with a sealing tape (tetrafluorinated ethylene resin unsintered tape for sealing described in JIS K6885), and the uncooked mackerel inside. A housed microwave cooking container was constructed. And this container for microwave oven cooking is put in the microwave oven (Panasonic company make model number: NE-1801), the output of the microwave is made 600W and irradiation time 80 seconds (2.67 seconds per 1g), grilled salt mackerel I did cooking.

  The same test evaluation as Example 1 was performed about the baking cooking in the microwave of the salt mackerel which used the above containers for microwave oven cooking.

Comparative Example
A commercially available container for microwave cooking (Asahi Kasei Home Products Co., Ltd. product name: Cook par oven for grilled fish box grilled) provided with a heat generating sheet of the same type as used in Examples 1 and 2 on the bottom of a paper food pack. ), 30 g of raw salt mackerel fillet was placed on the heating sheet so that the skin would be on the heating sheet side. Then, after assembling the container according to the instruction, put the container for microwave oven cooking containing fresh salted mackerel inside into the microwave oven (Panasonic make Model No .: NE-1801), output 600 W of microwave and irradiation time The salted mackerel was baked at 80 seconds (2.67 seconds per gram).

  The same test evaluation as Example 1 was performed about the baking cooking in the microwave of the salt mackerel which used the above containers for microwave oven cooking.

(Test evaluation result)
Table 1 shows the test evaluation results.

  According to Table 1, in all of Examples 1 and 2 and the comparative example, the salt mackerel was burnt well, and neither the deformation nor melting of the food pack of the microwave cooking container was observed. In Examples 1 and 2, the deformation and melting of the food pack were not observed because the food pack is formed of a highly heat-resistant crystalline polyester resin, and a heat generating sheet including a container body and a heat generating film. This is probably because the heat-insulating sheet is provided between and the heat-generating sheet is prevented from being affected by the heat. The deformation and melting of the food pack were not observed in the comparative example because the food pack was made of paper.

  In Examples 1 and 2, since the food pack is formed of a thermoplastic resin, it was possible to visually check the degree of salted mackerel burning from above and from the side during cooking in a microwave oven. In the comparative example, since the food pack was made of paper, it was impossible to visually check the degree of salted mackerel during cooking in the microwave oven. In Examples 1 and 2, the influence of the heat during cooking on the visibility of the inside of the food pack was not observed.

  The present invention is useful for microwave cooking containers.

F Foodstuff P Food pack 10 Container for microwave cooking 11 Container body 12 Lid 13 Heat generation sheet 13a Base material 13b Heat generation film 13c Coating film 14 Heat insulation sheet 15 Hinge part

Claims (8)

An upwardly open transparent container body formed of a thermoplastic resin comprising polylactic acid resin,
A heat generating film provided at the bottom of the container body and generating heat by microwaves of a microwave oven;
A heat insulating sheet provided between the container body and the heat generating film;
Equipped with a,
A container for microwave oven cooking, wherein an amide organic crystal nucleating agent is added to the thermoplastic resin forming the container body . A lid for closing the opening of the container body formed of the same thermoplastic resin as the container body;
The container for microwave oven cooking according to claim 1, wherein the container main body and the lid are integrally formed.   The microwave oven cooking according to claim 1 or 2, wherein the heat generating film is formed smaller than the heat insulating sheet, and is provided on the heat insulating sheet so that the heat insulating sheet protrudes from an outer periphery of the heat generating film. Container.   The container for microwave oven cooking according to any one of claims 1 to 3, wherein the thermoplastic resin forming the container body has crystallinity.   The container for microwave oven cooking as described in any one of Claims 1 thru | or 4 whose haze value of the said thermoplastic resin which forms the said container main body is 30% or less. The container for microwave oven cooking according to any one of claims 1 to 5, wherein the amide organic crystal nucleating agent is one or more compounds selected from fatty acid monoamides and fatty acid bisamides. The container for microwave oven cooking according to claim 6 , wherein the carbon number of the fatty acid in the one or more compounds selected from the fatty acid monoamide and the fatty acid bisamide is 8 or more and 24 or less. 8. The microwave oven according to any one of claims 1 to 7 , wherein the amount of the amide organic crystal nucleating agent added is 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the polylactic acid resin. container.

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