JP2008131923A - Frozen food tray and frozen food package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frozen food tray on which frozen food such as frozen sushi is appropriately thawed, and to provide a frozen food package using the frozen food tray. <P>SOLUTION: The frozen food tray 30 is provided with the following: a first intermediate face 33A and a second intermediate face 33B; recessed places 32A, 32B recessed from the intermediate faces 33A, 33B; a surrounding wall 34 rising from the peripheral parts of the intermediate faces 33A, 33B; and a flange part 35 forming the upper end part of the surrounding wall 34. Eight recessed places 32, in total, comprising every four sets in two rows respectively and lying in parallel in a long-side direction are formed in all directions. Four lower-bottom-face recessed places 32A at both end sides of the rows are recessed from the first intermediate face 33A at both end sides of the rows. Four higher-bottom-face recessed places 32B at the center sides of the rows are recessed from the second intermediate face 33B. The bottom faces of the higher-bottom-face recessed places 32B are located each at a position above the bottom face of the lower-bottom-face recessed place 32A. The microwave is passed through the space below the higher-bottom-face recesses 32B to heat the recesses 32B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tray for storing frozen food and a frozen food package using the tray.

  Techniques for thawing frozen sushi with microwaves such as microwave ovens are disclosed in JP-A-8-180790, JP-A-9-98888, JP-A-10-210960, JP-A-11-8058, JP-A-11-251054, JP-A-11-307239, and JP-A-2002-223711.

  In these known techniques, frozen sushi is placed on a flat plate-like thawing panel and irradiated with microwaves.

  It is desirable that the frozen sushi be thawed so that the shari is warmed to an appropriate temperature and the material is cold.

In the above prior art, the microwave intensity distribution is adjusted so that the microwave heats the shari rather than the neta. However, for all the frozen sushi on the thawing panel, the shari is at a suitable temperature and the neta is cold. It is not easy to defrost so that the material may get warm.
JP-A-8-180790 JP-A-9-98888 JP-A-10-210960 Japanese Patent Laid-Open No. 11-8058 JP-A-11-251054 Japanese Patent Laid-Open No. 11-307239 JP 2002-223711 A

  An object of the present invention is to provide a frozen food tray in which frozen food such as frozen sushi on the tray is appropriately thawed, and a frozen food package using the frozen food tray.

  The tray for frozen food of the first invention (invention 1) is a tray for frozen food having a recess for containing frozen food, the tray for frozen food comprising a surface layer made of synthetic resin, and a synthetic resin And a heat generating layer that is interposed between the surface layer and the back surface layer and generates heat by absorbing microwaves.

  The frozen food tray of claim 2 is characterized in that, in claim 1, the surface layer and the back layer are made of polypropylene or polystyrene.

  The tray for frozen food according to claim 3 is characterized in that, in claim 1 or 2, the heat generating layer contains at least one of carbon black and ferrite.

  The frozen food tray of the second invention (invention 4) includes a plurality of recesses for containing frozen foods, and at least a heating layer provided in the recesses for absorbing microwaves and generating heat. In the frozen food tray, the at least one recess is a high bottom recess whose bottom surface position is higher than the bottom surface positions of the other recesses.

  The tray for frozen food according to claim 5 is characterized in that, in claim 4, each recess has a side wall in the longitudinal direction, a side wall in the lateral direction, and a bottom surface.

  The tray for frozen food according to claim 6 is the tray for frozen food according to claim 5, wherein a plurality of recesses are arranged in parallel with each other in a row between the longitudinal side walls. In the at least one recess row, at least one recess in the row direction of the recess row is the high bottom recess.

  A tray for frozen food according to a seventh aspect is characterized in that, in the sixth aspect, the high bottom recess is arranged in the middle of the row direction in all rows.

  The frozen food tray of claim 8 is characterized in that, in claim 7, in the adjacent rows, the respective high bottom recesses are arranged adjacent to each other.

  A tray for frozen food according to claim 9 is the tray for frozen food according to claim 8, wherein the recess rows are provided in two rows, and each recess row is provided with four recesses, and the center side of each recess row. These two recesses are the high bottom recesses.

  The tray for frozen food according to claim 10 is the tray according to any one of claims 6 to 9, wherein the tray has an intermediate surface disposed in the middle of the vertical direction, and a plurality of the recesses recessed from the intermediate surface. And a surrounding wall rising from the peripheral edge of the intermediate surface.

  The frozen food tray of claim 11 has a first intermediate surface and a second intermediate surface higher than the first intermediate surface as the intermediate surface in claim 10, and the second intermediate The high bottom recess is disposed on a surface.

  The tray for frozen food according to claim 12 is characterized in that, in the first intermediate surface according to claim 11, a rib portion is provided between the side walls in the lateral direction of adjacent recesses. To do.

  A tray for frozen food according to a thirteenth aspect is characterized in that, in the twelfth aspect, the height of the rib portion is lower than the surrounding wall.

  The tray for frozen food according to claim 14 is the tray according to any one of claims 10 to 13, wherein the tray further has a raised portion that rises upward from a portion between the recesses. And the upper end of the surrounding wall have the same height.

  A frozen food tray according to a fifteenth aspect is characterized in that, in the fourteenth aspect, a flat surface is provided on each of the upper end of the surrounding wall and the upper end of the upright portion.

  The tray for frozen food according to claim 16 is the tray for frozen food according to claim 4 or 5, wherein the plurality of recesses are arranged in one row, and at least one recess in the longitudinal direction of the row is high. It is a bottom recess.

  The frozen food tray according to claim 17 is the frozen food tray according to any one of claims 4 to 16, wherein the frozen food tray comprises a synthetic resin surface layer, a synthetic resin back surface layer, and the surface layer and back surface. And a heat-generating layer that generates heat by absorbing microwaves.

  The tray for frozen food according to claim 18 is the tray according to any one of claims 1 to 17, wherein the recess communicates with a main recess in which the frozen food is accommodated and the main recess, and the frozen food is taken out. It sometimes comprises a sub-recess for inserting at least one of the finger and the frozen food take-out means.

  A frozen food package of a third invention (invention 19) is the frozen food tray according to any one of claims 1 to 18, and the frozen food housed in the recess of the frozen food tray, A synthetic resin packaging body for degassing and packaging the frozen food tray containing the frozen food, and a lid placed on the synthetic resin packaging body on the upper surface side of the frozen food tray; And a microwave shield provided on the lid.

  The frozen food package of claim 20 is characterized in that, in claim 19, the package is further encapsulated by shrink wrapping.

  The frozen food package of the fourth invention (invention 21) includes a frozen food tray, a frozen food stored in the frozen food tray, and a lid that covers an upper surface of the frozen food tray containing the frozen food. In the frozen food package, the frozen food tray has a recess for storing the frozen food, and at least a heating layer provided in the recess for absorbing microwaves and generating heat. The frozen food is contained in the recess, and the frozen food tray containing the frozen food is deaerated and packaged by a synthetic resin package, and the synthetic resin is disposed on the upper surface side of the frozen food tray. The lid is covered from above the package body, and the microwave shield is provided on the lid.

  A frozen food package according to a twenty-second aspect is characterized in that, in any one of the nineteenth to twenty-first aspects, the lid is made of paper and the micro is covered with a shield.

  A frozen food package of claim 23 is characterized in that, in any one of claims 19 to 22, the microwave shield is an aluminum foil.

  A frozen food package according to a twenty-fourth aspect of the present invention is the frozen food package according to any one of the nineteenth to twenty-third aspects, wherein the microwave shield has a size that covers an upper surface of the tray for the frozen food.

  In the frozen food tray of the first invention (invention 1), the heat generating layer is interposed between the surface layer and the back surface layer made of synthetic resin, and the heat generating layer is not exposed to the outside. For this reason, it is reliably prevented that the heat generating layer is rubbed against another object and peeled off.

  Moreover, this tray for frozen foods can be manufactured by pressure-molding the sheet | seat raw material which consists of this laminated body of a surface layer, a back surface layer, and a heat-generating layer. This is easier to manufacture than a case where a heat generating layer is formed by hand-coating a heating element on a tray made of synthetic resin. In addition, when the heating element is applied by hand, it is necessary to perform baking after application of the heating element in order to prevent the heating element from being peeled off, which is troublesome and the heating element layer becomes hard and easily broken by impact. On the other hand, since the both sides of the heat generating layer are protected by the front surface layer and the back surface layer in the frozen food tray of the present invention, there is no fear of peeling of the heat generating layer. For this reason, it is not necessary to bake the heat generating layer, and manufacturing is easy. Further, the heating layer is prevented from being hardened by baking.

  When the frozen food tray of the first invention (invention 1) is placed in a microwave oven and irradiated with microwaves, this heat generating layer absorbs the microwaves and generates heat, and this heat is transmitted to the frozen food. Defrosted. The heat generated in the heat generation layer is mainly transmitted through the heat transfer from the contact surface between the tray recess and the frozen food, the radiation from the non-contact surface, or the air layer between the tray recess and the frozen food. It is transmitted to frozen food by convection heat transfer. In this way, heating is performed so as to be wrapped from the recess, so that the thawing unevenness of the frozen food in the recess is prevented or suppressed.

  In the frozen food tray of the present invention, the front surface layer and the back surface layer are preferably made of polypropylene (PP) or polystyrene (PS). In particular, it is preferably made of polypropylene (PP) mixed with a filler made of an inorganic substance or the like (PPF). Since PPF is softer than synthetic resins such as PS and PP, it is difficult to crack even when subjected to an impact.

  In the frozen food tray of the present invention, the heat generating layer preferably contains at least one of carbon black and ferrite, and particularly preferably contains carbon black.

  In the frozen food tray of the second invention (invention 4), the microwave reaches the high bottom recess through the space below the high bottom recess. For this reason, the frozen food accommodated in the high bottom recess can be sufficiently heated. Moreover, frozen food with a small height can be stored in the high bottom recess, and frozen food with a large height can be stored in a recess with a low bottom.

  In the frozen food tray of the second invention (invention 4), it is preferable that the recess comprises a longitudinal side wall, a lateral side wall, and a bottom surface.

  In the tray for frozen food of the first invention (invention 4), a plurality of recesses are arranged in parallel with a plurality of recesses arranged at intervals between the longitudinal side walls. In the at least one recess row, at least one recess in the row direction of the recess row may be the high bottom recess.

  In all the rows, the high bottom recess may be arranged in the middle of the row direction.

  In the adjacent rows, it is preferable that the respective high bottom recesses are arranged adjacent to each other. Thereby, the microwave can pass through the lower space of each row of the high bottom recesses, and each of the high bottom recesses and the recesses in the vicinity thereof are sufficiently heated. Thereby, the frozen food in the recess arrange | positioned at the center side of a tray can also be fully heated.

  Even if at least one of the plurality of recess rows is a high and low recess, the microwave passes through the space below the high bottom recess row and is disposed on the center side of the tray. Even the recesses can be heated sufficiently.

  The frozen food tray of the second invention preferably has an intermediate surface arranged in the middle of the vertical direction, a plurality of the recesses recessed from the intermediate surface, and a surrounding wall rising from the periphery of the intermediate surface. Thereby, when storing frozen sushi as frozen food in the frozen food tray, it is possible to place the sushi ball portion of the frozen sushi in the recess of the tray so that the material is placed higher than the recess it can. Shari is heated to an appropriate temperature by heat transfer from the heat generation layer in the recess. On the other hand, since the material is higher than the recess, the material is thawed so that it gets cold.

  The intermediate surface has a first intermediate surface and a second intermediate surface higher than the first intermediate surface, and the high bottom recess is preferably disposed on the second intermediate surface. . As a result, a gap can be provided between the bottom of the high bottom recess and the tray installation surface, and the depth of the high bottom recess (distance from the second intermediate surface to the bottom of the high bottom recess). Can be adjusted to the depth of the other recess (the distance from the first intermediate surface to the bottom surface of the recess). For this reason, for example, even if frozen sushi of the same shape is stored in either a high bottom recess or another recess, the sharp ball part is placed in the recess and the material is placed higher than the recess Can be done. In addition to storing nigiri sushi in the high bottom recess, tall frozen foods such as cut thick rolls and California rolls can be stored in recesses other than the high bottom recess.

  The first intermediate surface may be provided with a rib portion between the side walls in the lateral direction of the adjacent recesses. Thereby, even when tall frozen foods such as thick rolls are stored in the recesses other than the high bottom recesses, the frozen foods are prevented from moving from the recesses during transportation.

  It is preferable that the height of the rib portion is lower than the surrounding wall. Thereby, when covering a cover on the upper surface of this frozen food tray, the back surface of the cover can be brought into contact with the upper end of the surrounding wall without being obstructed by the rib portion.

  The tray for frozen food of the second invention further has an upright portion that rises upward from a portion between the recesses, and the upper end of the upright portion and the upper end of the surrounding wall have the same height. Is preferred. Thereby, it becomes possible to support a cover body by this standing upper part. Thereby, even if the lid is pressed, it can be prevented from being broken or frozen food being pressed by the lid.

  By providing a flat surface on the upper end of these surrounding walls and the upper end of the upright portion, the lid can be appropriately supported.

  In the case where two of these plurality of recess rows are provided and four recesses are provided in each recess row, two recesses in the row direction of the recess rows are provided. It may be a high bottom recess.

  When a total of eight recesses are arranged in this way, the four recesses on the center side are less likely to be irradiated with microwaves than the four recesses on the outside. For this reason, it is preferable that these four recesses on the center side are high bottom recesses. As a result, even in the four high bottom recesses on the central side, microwaves are irradiated through the space below the high bottom recess, which is the same as the four outer recesses. Can be heated.

  In the frozen food tray of the second invention, the recesses are arranged in one row, and at least one recess in the longitudinal direction of the row may be a high bottom recess. As a result, the high bottom recesses can be heated strongly and can be heated to the same extent as the recesses arranged on both ends of the row.

  In the first and second inventions, these recesses communicate with the main recess in which the frozen food is accommodated, and at least one of the finger and the frozen food take-out means is inserted when the frozen food is taken out. It may consist of sub-recesses for Thereby, frozen food can be taken out easily from a recess.

  The frozen food package of the third invention (invention 19) is the degassed package of the frozen food tray of the first or second invention and the frozen food contained in the recess thereof with a synthetic resin package. . Thereby, the frozen food in the recess is pressed down by the synthetic resin package. For this reason, even if an impact is applied to the frozen food package during transportation or the package is turned over, the frozen food is prevented from jumping out of the recess. Further, for example, when the frozen food is frozen sushi, it is possible to prevent the material from being peeled off from the crisp balls. Furthermore, it is prevented that frozen food contacts the lower surface of the lid. In particular, even when a metallic microwave shield is provided on the lower surface of the lid, the frozen food is reliably prevented from coming into direct contact with the metallic microwave shield.

  In the third invention, since the lid body has the microwave shielding body, the microwave irradiated from above the frozen food package is shielded by the microwave shielding body. As a result, heating of the material is suppressed, so that the material can be thawed at an appropriate temperature and the material can be cooled.

  It is preferable that the frozen food package of the third invention is further shrink-wrapped. This reliably prevents the lid from coming off.

  Even in the frozen food package of the fourth invention (invention 21), the frozen food tray and the frozen food housed in the recess are deaerated and packaged with a synthetic resin package. Thereby, the frozen food in the recess is pressed down by the synthetic resin package. For this reason, even if an impact is applied to the frozen food package during transportation or the package is turned over, the frozen food is prevented from jumping out of the recess. Further, for example, when the frozen food is frozen sushi, it is possible to prevent the material from being peeled off from the crisp balls. Furthermore, the frozen food is prevented from coming into contact with the lower surface of the lid or the microwave shield disposed on the lower surface.

  In the fourth invention, since the lid body has the microwave shielding body, the microwave irradiated from above the frozen food package is shielded by the microwave shielding body. As a result, heating of the material is suppressed, so that the material can be thawed at an appropriate temperature and the material can be cooled.

  This lid may be made of paper. The microwave shield may be an aluminum foil. The microwave shield is preferably provided so as to cover the frozen food tray.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a perspective view of a frozen food tray 30 according to an embodiment, FIG. 2 is a plan view of the frozen food tray 30 of FIG. 1, FIG. 3, FIG. 4 (a), and FIG. FIGS. 6 and 6 are sectional views taken along lines III-III, IVa-IVa, VV, and VI-VI in FIG. 2, respectively. FIG. 4 (b) is an enlarged sectional view of a portion B in FIG. 4 (a). FIG. 7 is a perspective view of the frozen food tray 30 and the lid 60 shown in FIG. 1, and FIG. 8 is a rear view of the lid 60 shown in FIG. 9 and 10 are sectional views of the frozen food package 70 according to the embodiment.

  The tray for frozen food (hereinafter sometimes simply referred to as a tray) 30 includes a first intermediate surface 33A and a second intermediate surface 33B, and recesses 32A and 32B recessed from the intermediate surfaces 33A and 33B, and the intermediate A surrounding wall 34 erected from the peripheral edge of the surfaces 33A and 33B, a flange 35 constituting the upper end of the surrounding wall 34, a hanging part 36 depending from the outer periphery of the flange 35, and a hanging part 36 It has the overhang | projection part 37 projected over the side outward from a lower edge, and the standing part 39 standingly arranged from intermediate surface 33A, 33B.

  As shown in FIG. 2, the surrounding wall 34 has a substantially square frame shape, but the four corner portions are curved in an arc shape.

  The first intermediate surfaces 33A and 33A are arranged so as to be continuous with both sides of the second intermediate surface 33B. The second intermediate surface 33B is higher than the first intermediate surfaces 33A and 33A, and the boundary between the second intermediate surface 33B and the first intermediate surface 33A is a stepped portion (FIG. 1).

  Hereinafter, the recesses 32A and 32B may be collectively referred to as the recess 32.

  As shown in FIG. 2 and FIG. 5, the recesses 32 are provided in two rows of four, for a total of eight, vertically and horizontally. Two recesses 32B on the center side of each row are recessed from the second intermediate surface 33B, and two recesses 32A on both ends of the row are recessed from the first intermediate surface 33A.

  The recess 32 includes a main recess 32s for storing frozen food, and a sub-recess 32f for communicating with the main recess 32s and for inserting frozen food take-out means such as fingers and chopsticks when the frozen food is taken out. (Fig. 2).

  The main recess 32s has a substantially rectangular shape in plan view, and has long side walls 32a and 32a, short side walls 32b and 32b, and a bottom surface 32c (FIG. 2). Both corners where the side walls 32a and 32b of the recess 32 intersect are smoothly curved.

  The sub-recess 32f communicates with the side wall 32b on the surrounding wall 34 side of the main recess 32s.

  The sub-recess 32f has a shape in which a part of the lateral side wall 32b is bulged away from the main recess 32s.

  In a row composed of four recesses 32A, 32B, 32B, 32A, the lateral side walls 32b of the recesses 32A, 32B, 32B, 32A are oriented in the column direction. The lateral side walls 32b of the recesses 32A, 32B, 32B, 32A constituting one row are arranged on a straight line.

  Further, the longitudinal side walls 32a of the recesses 32A, 32B, 32B, 32A extend in a direction substantially orthogonal to the column direction. The longitudinal side walls 32a, 32a of the recesses 32A, 32A in adjacent rows are arranged in a straight line, and the longitudinal side walls 32a, 32a of the recesses 32B, 32B are also arranged in a straight line.

  The direction of the row composed of the four recesses 32A, 32B, 32B, 32A is parallel to one side of the surrounding wall 34.

  The low bottom recess 32A and the high bottom recess 32B have the same dimensions, and are large enough to accommodate the sushi balls of frozen sushi.

  As shown in FIGS. 3 and 4 (a), the bottom surface 32c of the high bottom recess 32B is higher than the bottom surface 32c of the low bottom recess 32A.

  The tray 30 is preferably sized to be placed in a commercial or home microwave oven.

  The flange portion 35 constitutes the upper end surface of the surrounding wall 34 and is provided over the entire circumference of the surrounding wall 34 so as to expand outward. The flange portion 35 is a flat surface, and supports a lid 60 described later.

  A drooping portion 36 that hangs down from the outer peripheral edge of the flange portion 35 circulates the entire circumference of the flange portion 35. A projecting portion 37 projects outward from the lower end of the hanging portion 36, and the projecting length of the projecting portion 37 is extremely small. By providing the hanging portion 36 and the overhanging portion 37, the rigidity of the tray 30 is increased, and a fingertip can be hung when the tray 30 is held.

  Three rising portions 39 are provided at intervals on the second intermediate surface 33B. The arrangement direction of the upright portions 39, 39, 39 is the same as the row direction of the four recesses 32A, 32B, 32B, 32A. The middle one of the three raised portions 39 is located at the center of the tray 1. The remaining two upright portions 39 are located in the vicinity of the stepped portion between the first intermediate surface 33A and the second intermediate surface 33B, respectively. The upper end surface of the upright portion 39 is a flat surface having the same height as the upper surface of the flange portion 35, and the lid body 60 can be supported by the top surface of the upright portion 39. The upright portion 39 is provided in a substantially conical shape so as to have a skirt in four directions.

  In the first intermediate surface 33A, a rib portion 39A is raised from a portion between the recesses 32A and 32A. Each rib portion 39A extends so as to connect the surrounding wall 34 and the upright portion 39 of the stepped portion. The width of the rib portion 39A is smaller than the interval between the recesses 32A and 32A in the first intermediate surface 33A, and there are flat first intermediate surfaces 33A on both sides of the rib portion 39A. By providing the rib portion 39 </ b> A, when frozen nigiri sushi is stored in the recess 32, the material is prevented from moving in the longitudinal direction of the recess 32. By providing the upright portion 39 and the rib portion 39A, the rigidity of the tray 30 is also improved.

  As shown in FIG. 4 (b), the tray 30 is composed of a laminated body 31 made up of a surface layer 31a and a back surface layer 31c made of synthetic resin, and a heat generating layer 31b interposed therebetween.

  The synthetic resin constituting the surface layer 31a and the back layer 31c is preferably made of PS (polystyrene) or PP (polypropylene), and in particular, a mixture of polypropylene (PP) and a filler made of an inorganic substance or the like (PPF) It is particularly preferable that

  The thicknesses of the front surface layer 31a and the back surface layer 31c are preferably 5 to 100 μm, more preferably 10 to 80 μm, and particularly preferably about 20 to 70 μm.

  As a heat generating material for the heat generating layer 31b, carbon black or the like is suitable, but is not limited thereto.

  In order to manufacture the laminate 31, for example, a carbon ink in which carbon black is dispersed in an organic solvent made of toluene, ethyl alcohol, isopropyl alcohol, methyl ethyl ketone, propylene glycol, monomethyl ether, or the like is prepared. The carbon ink is attached to the outer surface of the surface layer 31a by a technique such as spraying, brushing, dipping, and the like, and dried to form the heat generating layer 31b. In addition, it is preferable to degrease the outer surface of the surface layer 31a before forming the heat generating layer 31b. Subsequently, the laminated body 31 is formed by forming the back surface layer 31c in this heat-generating layer 31b. In addition, the tray 30 is formed by press-molding the laminated body 31 with a mold or the like.

  The thickness of the heat generating layer 31b is preferably about 10 to 100 μm, particularly about 10 to 80 μm, particularly about 30 to 60 μm.

  When the frozen food tray 30 is used as a frozen sushi tray, the height difference between the first intermediate surface 33A and the second intermediate surface 33B is preferably about 5 to 25 mm, particularly about 10 to 15 mm. The height difference between the recess 32A and the recess 32B is preferably about 5 to 25 mm, particularly about 10 to 15 mm.

  In order to construct a frozen sushi package using the tray 30 configured in this way, the frozen sushi 40 is accommodated in each recess 32 (32A, 32B), and the tray 30 and the frozen sushi 40 are made of synthetic resin. The package 50 is degassed and packaged. Next, the frozen food package 70 is configured by covering the top surface of the tray 30 with the lid 60 from above the synthetic resin package 50. The frozen food package 70 may be further shrunk. When shrink wrapping is not applied, the lid body 60 is fixed by winding a wrap or putting it in an outer box.

  The synthetic resin package 50 is preferably a thermoplastic synthetic resin bag such as nylon or polyethylene, but is not limited thereto as long as it has resistance to microwave irradiation.

  The lid 60 is preferably made of paper, but is not limited to this as long as it has resistance to microwave irradiation.

  As shown in FIGS. 7 and 8, the lid 60 includes a substantially square lid body 61, a first extension 62 extending outward from its four sides, and an outside of the first extension 62. The second extending portion 63 extends outward from the end. The lid body 60 can be bent along a boundary line 64 between the lid body 61 and the first extension portion 62, and the boundary between the first extension portion 62 and the second extension portion 63. It can be bent along the line 65. An aluminum foil 66 as a microwave shield is bonded to the back surface of the lid 60.

  If the aluminum foil 66 has a small thickness, the aluminum foil itself generates heat and excessively raises the temperature of the material. Therefore, the aluminum foil 66 is desirably 10 μm or more, particularly 12 μm or more. The aluminum foil 66 is desirably 100 μm or less, particularly 50 μm or less, especially 20 μm or less, for cost reduction. The aluminum foil preferably has a size that covers the entire open upper surface of the tray 30.

  As shown in FIG. 9, when the lid 60 is placed on the tray 30, the peripheral portion of the lid body 61 faces the flange portion 35 of the tray 30 via the synthetic resin package 50. In addition, the first extending portion 62 is folded downward from the boundary line 64 and the second extending portion 63 is folded inward from the boundary line 65.

  When this sushi 40 is nigiri sushi, it has a sharp ball 41 and a material 42 on the sharp ball 41. Wasabi is interposed between the ball 41 and the material 42 as necessary. Examples of the material 42 include fish and shellfish such as salmon, toro, squid, octopus, shellfish, shrimp and conger, cooked products thereof, egg roasting, and the like, but are not limited thereto.

  As shown in FIG. 9, the frozen sushi 40 has the whole or most of the shaving balls 41 disposed in the recess 32, and the entire material 42 is disposed above the level of the intermediate surfaces 33A and 33B. A very small part of the material 32 may exist in the recess 32. It is desirable that 90% or more, particularly 95% or more, of the sprout balls 31 is disposed in the recess 32 (that is, lower than the intermediate surfaces 33A and 33B).

  Usually, it is preferable that the size of the sushi balls of frozen sushi is about 10 to 50 g, particularly 15 to 40 g, particularly about 18 to 25 g. The material is preferably about 3 to 40 g, particularly about 5 to 30 g, especially about 6 to 20 g.

  Generally, as in the case of the tray 30 of the present embodiment, in the case where the recesses are provided in two rows of four in parallel with the long side direction, a total of eight, vertically and horizontally, the center side of the tray The four recesses located are less likely to receive microwaves than the four recesses located outside the tray.

  However, in the tray 30 according to the present embodiment, the position of the bottom surface 32c of the high bottom recess 32B is higher than the position of the bottom surface 32c of the low bottom recess 32A. There is a gap below the high bottom recess 32B. Therefore, the microwaves reach the elevation recess 32B through the gap, and heat the elevation bottom recess 32B. Thereby, it becomes possible to heat the frozen sushi 40 in the high bottom recess 32B to the same extent as the frozen sushi 40 in the low bottom recess 32A.

  In FIG. 9, frozen sushi 40 made of nigiri sushi is stored in both the low bottom recess 32A and the high bottom recess 32B. However, as shown in FIG. 10, the low bottom recess 32A has a large height. A roll 40A such as a thick roll or a California roll may be stored. As shown in FIG. 10, since the distance from the bottom surface 23c of the low bottom recess 32A to the upper end (flange portion 30) of the tray 30 is large, it is possible to sufficiently accommodate a tall roll 40A or the like.

  In the frozen food package 70 of the present embodiment, the frozen sushi 40 accommodated in the frozen food tray 30 and its recess 32 (32A, 32B) is deaerated and packaged with a synthetic resin package 50. is doing. This prevents the frozen sushi 40 from popping out of the recess 32 even if an impact is applied to the frozen food package 70 during transportation or the package 70 is turned over. In addition, the material is prevented from peeling off from the sharp balls. Furthermore, the frozen sushi 40 is prevented from coming into contact with the lid 60 and the aluminum foil 66. Further, since the aluminum foil 66 is disposed on the lower surface of the lid 60, the microwave irradiated from above the frozen food package 70 is shielded by the aluminum foil 66. As a result, heating of the material is suppressed, so that the material can be thawed at an appropriate temperature and the material can be cooled.

  In the above description, the frozen food is frozen sushi. However, by changing the size and number of the recesses 32, the frozen food can be applied to various confectionery such as frozen cake, frozen rice cake, and frozen curry rice.

  Moreover, the number and arrangement | positioning of a recess and a high bottom recess are not limited to this, What is necessary is just to select according to the magnitude | size of a tray. For example, three or five or more recesses 32 may be provided in one row. When five or more recesses 32 are provided in one row, the number of the recesses 32 arranged on the first intermediate surface 33A may be one or may be two or more. In the above embodiment, two rows of the recesses 32A, 32B, 32B, 32A are provided, but three or more rows may be provided.

  In the present invention, only one row may be provided.

  FIG. 11 is a perspective view of a frozen food tray 1 according to another embodiment, FIG. 12 (a) is a longitudinal sectional view illustrating a state in the middle of manufacturing a frozen food package using the tray 1, and FIG. FIG. 12B is an enlarged view of a portion B in FIG.

  This tray for frozen food (hereinafter sometimes simply referred to as a tray) 1 includes a main bottom surface 3, a recess 2 that is recessed from the main bottom surface 3, and a surrounding wall 4 that is erected from the peripheral edge of the main bottom surface 3. A flange portion 5 that constitutes the upper end portion of the surrounding wall 4, a hanging portion 6 that hangs down from the outer peripheral edge of the flange portion 5, and an overhang portion 7 that projects outward from the lower edge of the hanging portion 6 And ribs 8 provided at the corners of the main bottom surface 3 and the surrounding wall 4, and an upright portion 9 erected from the main bottom surface 3.

  The recess 2 has a substantially rectangular shape in plan view, and has a side wall 2a in the longitudinal direction, a side wall 2b in the lateral direction, and a bottom surface 2c. The recesses 2 are provided in two rows of four in parallel with the long side direction in parallel, for a total of eight, vertically and horizontally.

  The recess 2 is sized to accommodate a sushi ball of frozen sushi. In addition, both corners where the side walls 2a and 2b of the recess 2 intersect are smoothly curved.

  The main bottom surface 3 has a substantially square outer edge shape, but the four corner portions along the surrounding wall 4 are curved in an arc shape.

  The main bottom surface 3 between the side walls 2a, 2a in the longitudinal direction of the adjacent recesses 2, 2 is a strip-shaped portion 3a extending along the side walls 2a, 2a.

  The main bottom surface 3 between the side walls 2b, 2b in the short direction of the adjacent recesses 2, 2 extends along the side walls 2b, 2b.

  The surrounding wall 4 is provided so as to go around the entire periphery of the main bottom surface 3. The surrounding wall 4 has a wall 4a parallel to the side wall 2a in the longitudinal direction of the recess 2 and a wall 4b parallel to the side wall 2b in the short side direction. The rib 8 is provided at a crossing corner between the wall 4 b of the surrounding wall 4 and the main bottom surface 3.

  The flange portion 5 constitutes the upper end surface of the surrounding wall 4 and is provided over the entire circumference of the surrounding wall 4 so as to expand outward. The flange portion 5 is a flat surface.

  A drooping portion 6 that hangs down from the outer peripheral edge of the flange portion 5 circulates the entire circumference of the flange portion 5. An overhanging portion 7 projects outward from the lower end of the hanging portion 6, and the overhanging length of the overhanging portion 7 is extremely small. By providing the hanging portion 6 and the overhanging portion 7, the rigidity of the tray 1 can be increased, and a fingertip can be hung when the tray 1 is held.

  The upright portion 9 is located at the intersection of the belt-like portions 3a and 3b. The upper end surface of the upright portion 9 is a flat surface having the same height as the upper surface of the flange portion 5. The upright portion 9 is provided in a substantially conical shape so as to draw a skirt in four directions, that is, in the directions of the belt-like portions 3a, 3a, 3b, 3b.

  A rib portion 9A is raised from the belt-like portion 3b. The rib portion 9 </ b> A extends between the rising portions 9 and 9 so as to connect the rising portions 9 and 9. The rib portion 9 </ b> A also extends so as to connect the upright portion 9 and the wall 4 a of the surrounding wall 4. The width of the rib portion 9A is smaller than the width of the strip portion 3b, and the strip portion 3b exists on both sides of the rib portion 9A. Providing the rib portion 9A prevents the material from moving in the longitudinal direction of the recess 2. By providing the upright portion 9 and the rib portion 9A, the rigidity of the tray 1 is also improved.

  As shown in FIG. 12 (b), the tray 1 includes a synthetic resin main body 1a and a heat generation layer 1b formed on the outer surface of the main body 1a. Examples of the synthetic resin constituting the tray body 1a include polypropylene, but are not limited thereto. The thickness of the tray body 1a is preferably 100 to 1500 μm, more preferably 300 to 800 μm, and particularly preferably about 500 to 800 μm.

  In this embodiment, the heat generating layer 1b includes the entire outer surface of the tray 1, that is, the outer surface of the bottom surface 2c of the recess 2 and the outer surfaces of the side walls 2a and 2b, the lower surface of the main bottom surface 3, the outer surface of the surrounding wall 4 and the lower surface of the flange portion 5. The portion 6 is formed on the surface facing the surrounding wall 4, the lower surface of the overhang 7, the lower surface (back surface) of the rib 8, and the lower surface (back surface) of the raised portion 9.

  However, the heat generating layer 1b may not be provided partially. For example, the heat generating layer 1 b may not be provided on the flange portion 5, the hanging portion 6, and the overhang portion 7. The thickness of the heat generating layer 1b may be uniform as a whole or may be partially thick. For example, the heat generating layer 1b on the bottom surface or side surface of the recess 2 may be thicker than other portions.

  The heat generating layer 1b is formed by adhering a paint in which the resin for forming the coating film is dissolved and the powder of the heat generating element is dispersed to the outer surface of the tray main body 1a by a technique such as spraying, brushing, dipping, etc. That is suitable. As the heating element, ferrite, carbon black, or the like is used, and carbon black is preferable. The thickness of the heat generating layer 1b is preferably about 10 to 100 μm, particularly about 10 to 80 μm, especially about 30 to 60 μm. In addition, it is preferable to degrease the outer surface of the tray main body 1a prior to coating film formation.

  In the recess 2 of the tray 1 configured in this manner, the frozen sushi 40 is accommodated in the same manner as in the above embodiment, and then the tray 30 and the frozen sushi 40 are deaerated and packaged by the synthetic resin package 50. Is done. Next, the upper surface of the tray 30 and the frozen sushi 40 is covered with a lid 60 from above the synthetic resin package 50, whereby the frozen food package 70 is configured.

  Even in the frozen food package according to the present embodiment, the frozen food tray 1 and the frozen food 10 accommodated in the recess 2 are deaerated and packaged by the synthetic resin package 50. This prevents the frozen food 10 from jumping out of the recess 32 even if an impact is applied to the frozen food package during transportation or the package is turned over. In addition, the material is prevented from peeling off from the sharp balls. Further, the frozen food 10 is prevented from coming into contact with the lid 60 and the aluminum foil 66. Further, since the aluminum foil 66 is disposed on the lower surface of the lid 60, the microwave irradiated from above the frozen food package 70 is shielded by the aluminum foil 66. As a result, heating of the material is suppressed, so that the material can be thawed at an appropriate temperature and the material can be cooled.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

  In the embodiment, in the frozen food package 70 described above, the first intermediate surface 33A and the second intermediate surface 33B having different height positions are used. In Comparative Example 1, the frozen food package 70 in which the height position of the first intermediate surface 33A is matched with the height position of the second intermediate surface 33B is used. The frozen food package 70 will be described below.

  In the laminated body 31 constituting the tray 30, the front surface layer 31a is a 65 μm thick PPF, the back surface layer 31b is a 25 μm thick PPF, and the heat generating layer 31b is a 40 μm thick carbon black layer. The carbon black content in the composite material layer is about 34% by weight.

The dimensions of each part of the tray 1 are as follows.
Tray side length: 210mm
Depth of recess 32A, 32B: 20mm
Size of recess 32A, 32B, upper part: 62 × 32mm
Bottom: 57x27mm
Difference in height between the height position of the first intermediate surface 33A and the height position of the second intermediate surface 33B
: Same height (Comparative Example 1)
: 5 mm (Example 1)
: 10 mm (Example 2)
: 15 mm (Example 3)
Height from the first intermediate surface 33A to the upper end (flange portion 35) of the surrounding wall 34: 22 mm

  Frozen sushi (stuff: tuna) is accommodated in a total of eight recesses 32 of this tray 1, and most of the sharp balls 41 are arranged in the recesses 32 as shown in FIG. 33A and higher than the second intermediate surface 33B. Shari ball 41 is 22 g, and material 42 is an average of 10 g.

  As the synthetic resin package 50, a nylon bag having a thickness of 85 μm was used. The tray 30 containing the frozen sushi 40 was deaerated and packaged using this nylon bag.

  In the lid 60, the lid body 61 was made of paper having a thickness of 0.6 mm, and the aluminum foil 66 was made 15 μm in thickness.

[Examples and Comparative Examples]
Each frozen food package 70 (freezing temperature: −20 ° C.) of Comparative Example 1 and Examples 1 to 3 stored in the frozen state is put into a microwave oven “NE-S22F” (microwave output: 600 W) manufactured by National Corporation. It was heated for 2 minutes and 20 seconds, and then allowed to thaw for 5 minutes. Ten tests were conducted, and the temperature (° C.) of each ball and material was measured. The results are shown in Tables 1-4.

  In addition, the frozen sushi arranged in each recess was named as shown in FIG. 13 (a). Further, as shown in FIG. 13 (b), the temperature measurement position of the sharp ball is the center of the sharp ball, and the temperature measurement position of the material is the center of the upper surface of the material.

As is clear from the comparison between Comparative Example 1 and Examples 1 to 3, by making the four recesses on the central side into high-bottom recesses, the frozen sushi in the four recesses on the central side and the outside In the frozen sushi in the four recesses, the temperature difference between the crisp balls and the temperature difference between the material became smaller.

  In particular, in the frozen sushi of Examples 2 and 3, the temperature difference of the shari balls and the temperature difference of the material were improved within a range of 5 to 10 ° C. This is because, by providing a high bottom recess, a space is created between the bottom of the high and low recess and the bottom of the microwave when the package is accommodated in the microwave. This is considered to be because the microwave was sufficiently irradiated to the high bottom recess on the side.

  From the above, it has been found that the height difference between the four elevation recesses on the central side and the four lower recesses on the outer side is preferably 10 mm or more. In order to avoid bulkiness, the height difference is more preferably 10 mm.

It is a perspective view of the tray 30 for frozen food which concerns on embodiment. It is a top view of the tray 30 for frozen foods of FIG. It is sectional drawing which follows the III-III line of FIG. (A) is sectional drawing which follows the IVa-IVa line | wire of FIG. 2, (b) is an expanded sectional view of the B section of (a). It is sectional drawing which follows the VV line of FIG. It is sectional drawing which follows the VI-VI line of FIG. FIG. 3 is a perspective view of the frozen food tray 30 and the lid 60 of FIG. 1. It is a reverse view of the cover body 60 of FIG. It is sectional drawing of the frozen food package 70 which concerns on embodiment. It is sectional drawing of the frozen food package 70 which concerns on embodiment. It is a perspective view of the tray 1 for frozen food which concerns on another embodiment. (A) is a longitudinal cross-sectional view explaining the state in the middle of manufacture of the frozen food package using the tray 1 of FIG. 11, (b) is an enlarged view of B part of (a). (A) is drawing explaining the arrangement | positioning of frozen sushi in an Example, (b) is drawing explaining the temperature measurement position of frozen sushi.

Explanation of symbols

30 Tray for frozen food 31 Laminate 31a Surface layer 31b Heat generation layer 31c Back layer 32 Recess 32A Low bottom recess 32B High bottom recess 32s Main recess 32f Sub recess 33A First intermediate surface 33B Second intermediate surface 34 Enclosing wall 35 Flange part 36 Hanging part 37 Overhang part 38 Rib 39 Standing part 40 Frozen food 50 Synthetic resin packaging body 60 Lid body 66 Aluminum foil

Claims (24)

In the frozen food tray with a recess for containing frozen food,
The tray for frozen food includes a surface layer made of synthetic resin, a back surface layer made of synthetic resin, and a heat generating layer that is interposed between the surface layer and the back surface layer and generates heat by absorbing microwaves. A featured tray for frozen food.   2. The frozen food tray according to claim 1, wherein the front surface layer and the back surface layer are made of polypropylene or polystyrene.   3. The tray for frozen food according to claim 1, wherein the heat generating layer contains at least one of carbon black and ferrite. In a frozen food tray having a plurality of recesses for containing frozen foods, and at least a heating layer provided in the recesses to absorb microwaves and generate heat,
The tray for frozen food, wherein the at least one recess is a high bottom recess whose bottom surface position is higher than the bottom surface position of the other recesses.   5. The tray for frozen food according to claim 4, wherein each recess has a longitudinal side wall, a lateral side wall, and a bottom surface. In claim 5, a plurality of recesses are arranged in parallel, and a plurality of recesses are arranged in parallel with each other between the longitudinal side walls.
In at least one recess row, at least one recess in the row direction of the recess row is the high bottom recess.   The frozen food tray according to claim 6, wherein in all the rows, the high bottom recess is arranged in the middle of the row direction.   8. The frozen food tray according to claim 7, wherein in the adjacent rows, the respective high bottom recesses are arranged adjacent to each other.   9. The recess row according to claim 8, wherein two recess rows are provided, and each recess row is provided with four recesses, and two recesses on the center side of each recess row are the high bottom surfaces. A tray for frozen food, characterized by a recess.   The tray according to any one of claims 6 to 9, wherein the tray includes an intermediate surface disposed in the middle of the vertical direction, a plurality of the recesses recessed from the intermediate surface, and a surrounding wall rising from a peripheral edge of the intermediate surface. A tray for frozen food, characterized by comprising: In Claim 10, it has the 1st intermediate surface and the 2nd intermediate surface higher than this 1st intermediate surface as said intermediate surface,
A tray for frozen food, wherein the high bottom recess is disposed on the second intermediate surface.   The tray for frozen food according to claim 11, wherein a rib portion is provided between the lateral side walls of adjacent recesses on the first intermediate surface.   The tray for frozen food according to claim 12, wherein a height of the rib portion is lower than the surrounding wall.   The tray according to any one of claims 10 to 13, further comprising an upright portion that rises upward from a portion between the recesses, and an upper end of the upright portion and an upper end of the surrounding wall are the same. A tray for frozen food, characterized by its height.   15. The tray for frozen food according to claim 14, wherein a flat surface is provided at each of an upper end of the surrounding wall and an upper end of the upright portion. In claim 4 or 5, the plurality of recesses are arranged in a row,
A tray for frozen food, wherein at least one recess in the longitudinal direction of the row is a high bottom recess.   The frozen food tray according to any one of claims 4 to 16, wherein the frozen food tray is interposed between a surface layer made of a synthetic resin, a back layer made of a synthetic resin, and the surface layer and the back layer. A tray for frozen food, comprising a heat generating layer that absorbs heat and generates heat.   18. The recess according to claim 1, wherein the recess communicates with the main recess in which the frozen food is accommodated, and at least of the finger and the frozen food take-out means when the frozen food is taken out. A tray for frozen food, comprising a sub-recess for inserting one side. A frozen food tray according to any one of claims 1 to 18,
Frozen food contained in the recess of the frozen food tray;
A synthetic resin packaging body for degassing and packaging the tray for frozen food containing the frozen food;
A lid placed over the synthetic resin packaging body on the top surface side of the frozen food tray;
A frozen food package comprising a microwave shield provided on the lid.   20. The frozen food package according to claim 19, wherein the package is further encapsulated by shrink wrapping. In a frozen food package having a frozen food tray, a frozen food stored in the frozen food tray, and a lid that covers an upper surface of the frozen food tray containing the frozen food,
The frozen food tray has a recess for containing frozen food, and at least a heating layer provided in the recess to absorb microwaves and generate heat,
The frozen food is contained in the recess;
The frozen food tray containing the frozen food is degassed and wrapped by a synthetic resin package;
The lid is put on the synthetic resin packaging body on the upper surface side of the frozen food tray,
A frozen food package, wherein a microwave shield is provided on the lid.   The frozen food package according to any one of claims 19 to 21, wherein the lid is made of paper and the microwave shield is attached thereto.   23. The frozen food package according to claim 19, wherein the microwave shield is an aluminum foil.   24. The frozen food package according to any one of claims 19 to 23, wherein the microwave shield has a size covering an upper surface of the frozen food tray.

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