TW201601975A - Food container and manufacturing method thereof - Google Patents

Abstract

The present invention prepares a resin-made inner container 2 that does not contain a metal layer and shapeable plate 80 that contains at least one metal layer. During stretching and shaping the shapeable plate 80 to form an outer container 3 and having the outer container and an outside surface of the inner container 2 overlapped to integrate the two containers 2, 3 in a releasable manner to form a food container, the manufacture of the food container is conducted under the condition that X ≥ Y, with X being an outside diameter of an opening of the inner container before the stretching and shaping operation and Y being an inside diameter of an opening of a die casting mold 82 that is used in the stretching and shaping operation of the outer container. The food container so obtained shows excellent gas barrier property as a container and helps prevent the generation of sparks during heating with a microwave oven, and the container does not easily reach a high temperature, has a high efficiency of heating food, and does not easily cause non-uniform heating of food.

Description

Food container and method of manufacturing same

The present invention relates to a food container for preventing the generation of sparks when a food such as a liquid or a solid is placed in a container, and a method for producing the same.

Since the container containing a metal layer is excellent in gas barrier property, it is widely used as a food container. However, when a foodstuff containing such a metal layer container is heated by a microwave oven, in the past, the foodstuff was converted into a glass container or The ceramic vessel is then heated in a microwave oven. The conversion of such foods is carried out because when a container containing a metal layer is used in a microwave oven, there is a problem that a metal layer exposed at the flange end of the container generates a spark, and the container may burn, and the contents may be Food quality has an impact.

When a container containing a metal layer is used in a microwave oven, in order to solve the above problem, Patent Document 1 proposes a container for a microwave oven, which is a container formed by coating both sides of a metal foil with a thermoplastic resin, and is characterized in that the outer package covers the convexity of the container. In the edge portion, a fireproof member having a loss coefficient (ε‧tan δ) of 0.001 or less, a softening point temperature of 100 ° C or more, and a height of 3.5 mm or more is provided at a central portion of the outer surface of the bottom portion of the container, The cross-sectional area of the spark-proof member is 1% or more with respect to the bottom area of the container, and is 20 mm ² or more. Patent Document 1 discloses that a flame-proof member having the above-described various features is provided, and the flange end portion of the container is covered by the outer package to prevent the end portion of the metal layer from being exposed, thereby preventing sparking when heated in a microwave oven.

[Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2006-131270

However, the container disclosed in Patent Document 1 does not have a metal layer exposed. However, since it is a container containing a metal layer, when the container is heated in a microwave oven, electromagnetic waves are shielded by the presence of a metal layer, and the food placed in the container is irradiated. The electromagnetic wave is only applied to the opening of the container (usually the opening of the upper end of the container), the heating efficiency of the food is low, the heating temperature of the food is liable to be uneven (the local heating temperature is uneven in the food), and the liquid is contained. Food may have a sudden boiling due to uneven heating.

Further, in the container described in Patent Document 1, since the metal layer in the container has a large thermal conductivity, the temperature (heat) of the food heated by the microwave oven is easily conducted to the outer surface of the container, causing the container to be heated to a high temperature, and the container is heated and taken out of the container. It is difficult to hold the problem directly by hand.

Further, in the container described in Patent Document 1, a part of the metal layer may be exposed by contact with other articles or an external collision, and a spark may be generated when the container in which such a metal layer is exposed is heated in a microwave oven.

The present invention has been made in view of such a technical background, and an object thereof is to provide a gas barrier which is excellent in barrier properties as a container, protects a food from oxygen and moisture, and prevents sparking when heated in a microwave oven, and A container for foods and a method for producing the same, in which the container is not easily heated to a high temperature, the heating efficiency of the food is high, and the food is not heated unevenly.

In order to achieve the aforementioned objects, the present invention provides the following means.

[1] A method for producing a food container, comprising: preparing a resin-made inner container containing no metal layer; and molding a sheet containing at least a metal layer; and performing the molding sheet a step of forming the outer container by stretch molding, and superposing the outer container on the outer surface of the inner container to separate the two containers separately; and opening the inner container before the stretch forming of the preparation When the outer diameter of the opening of the die-casting mold used for the stretch molding of the outer container is "Y", the relationship of X≧Y is established when the outer diameter is "X".

[2] The method for producing a food container according to the above item 1, wherein a relationship of 0 mm ≦ (X-Y) ≦ 10 mm is established.

[3] The method for producing a food container according to the above item 1, wherein a relational expression of 0.5 mm ≦ (X-Y) ≦ 4.0 mm is established.

[4] A food container comprising: a resin inner container having no metal layer; and a container having at least a metal layer; and the outer container is superposed on the outer surface of the inner container to separate the two containers When the two integrated containers are separated, the outer diameter of the opening of the inner container in the separated state is "E", and when the inner diameter of the opening of the outer container in the separated state is "F", E≧F

The relationship is established.

[5] The food container according to the above item 4, wherein a relationship of 0 mm ≦ (E-F) ≦ 10 mm is established.

[6] The food container according to the above item 4 or 5, wherein the fourth flange portion is extended from the peripheral edge of the opening portion of the upper end of the outer container toward the horizontal direction, and the outer peripheral edge of the fourth flange portion is oriented. a stepped portion is extended substantially upward, and a fifth flange portion is extended from the upper end of the step portion toward the horizontal direction; and a sixth flange portion is extended from the periphery of the opening portion of the upper end of the inner container toward the horizontal direction. The lower surface of the sixth flange portion abuts on the upper surface of the fourth flange portion of the outer container, and the front edge of the sixth flange portion abuts against the inner circumferential surface of the step portion of the outer container.

[7] The food container according to Item 6, wherein at least the outer peripheral edge portion of the upper surface of the fifth flange portion of the outer container does not have the constituent members of the inner container.

[8] The food container according to the above item 4 or 5, wherein the first flange portion is extended from the peripheral edge of the opening portion of the upper end of the inner container toward the outside in the horizontal direction, and the outer peripheral edge of the first flange portion is provided. a stepped portion is extended toward the lower portion, and a second flange portion is extended from the lower end of the step portion toward the horizontal direction; and a third flange portion is extended from the periphery of the opening portion of the upper end of the outer container toward the horizontal direction. The upper surface of the third flange portion is abutted against the lower surface of the first flange portion of the inner container, and the front edge of the third flange portion abuts against the inner peripheral surface of the step portion of the inner container.

[9] The food container according to Item 8, wherein at least the outer peripheral edge portion of the lower surface of the second flange portion of the inner container does not have the constituent members of the outer container.

[10] The food container according to any one of the preceding items, wherein the outer surface of the inner container is made of polypropylene or crystalline polyethylene terephthalate; Propylene, polyethylene, nylon, epoxy resin, epoxy melamine resin, acrylic resin, urethane resin, vinyl acetate resin or aluminum.

[11] The food container according to any one of the preceding items, wherein the two containers are used in an integrated state before heating in a microwave oven, and when the microwave oven is heated, the two containers are separated, and only the inner side is used. The container is heated by a microwave oven.

[12] A method of producing a double container filled with food, comprising: a step of loading food into an inner container of the food container in an integrated state according to any one of items 4 to 11; a step of sealing the opening of the inner container by joining the lid to the container; and a step of heat-sterilizing the sealed food container.

According to the inventions of [1] and [2], the outer container containing the metal layer is superposed on the outer surface of the inner container made of a resin containing no metal layer by stretch forming, and the two containers can be manufactured and separated. Food container. In this case, the outer diameter of the opening of the inner container before the stretch molding is prepared is "X", and the inner diameter of the opening of the die-casting mold for the stretch molding die used for the stretch molding of the outer container is set to In the case of "Y", since it is manufactured under the condition that the relationship of X≧Y is established, the inner container and the outer container can be manufactured with sufficient strength. And an integrated food container. Therefore, the obtained food container can completely prevent separation of the two containers during storage and when the food is filled. Further, after the food container is subjected to the heat treatment for sterilization, the heat shrinkage of the inner container and the outer container is poor during the subsequent cooling, so that the integration strength between the inner container and the outer container integrated with sufficient strength is lowered. Therefore, after the heat sterilization treatment, the inner container and the outer container can be easily separated by a human hand.

Then, in the state in which the food container having the food is placed, the outer container contains the metal layer, and the container is excellent in gas barrier properties, and the food can be protected from oxygen and moisture.

In addition, when the foodstuff in the food container in which the foodstuff has been filled is heated by a microwave oven (because it has been subjected to heat sterilization treatment), the inner container and the outer container can be easily separated by hand, and only the inner container in which the food is loaded can be used. It is placed in a microwave oven for heating. Since the inner container has no metal layer, it can prevent sparks when heated in a microwave oven, and it is difficult to achieve high temperature in the container, the heating efficiency of the food is high, and food heating unevenness is not easily generated. The effect of the situation.

According to the invention of [3], since the relationship is established in a relationship of 0.5 mm XY (XY) ≦ 4.0 mm, the integration strength between the inner container and the outer container can be further increased. The state of integration of the two containers is more stable.

[4] The invention of the invention (the container for foods) is characterized in that the food container obtained by the production method according to any one of the above [1] to [3] is provided, and the food container is not included in the composition. The outer surface of the inner container made of a resin of the metal layer is superposed on the outer container including the metal layer, and the two containers are integrated and separable, and when the two integrated containers are separated, the outer container is separated from the opening of the inner container in the separated state. The diameter is set to "E", and the opening of the container on the outer side of the separation state is When the inner diameter is set to "F", the relationship of E≧F is established. The inner container and the outer container of the food container having such a configuration are integrated with sufficient strength.

Then, in the state in which the food container of the present invention containing the food is stored, the outer container contains a metal layer, and the gas barrier property of the container is excellent, and the food can be protected from oxygen and moisture.

In addition, when the foodstuff in the food container in which the foodstuff has been filled is heated by a microwave oven (because it has been subjected to heat sterilization treatment), the inner container and the outer container can be easily separated by hand, and only the inner container in which the food is loaded can be used. It is placed in a microwave oven for heating. Since the inner container has no metal layer, it can prevent sparks when heated in a microwave oven, and it is difficult to achieve high temperature in the container, the heating efficiency of the food is high, and food heating unevenness is not easily generated. The effect of the situation.

According to the invention of [6], the integration strength between the inner container and the outer container can be further increased, and the state in which the two containers are integrated can be made more stable.

[7] The invention is characterized in that at least the outer peripheral edge portion of the upper surface of the fifth flange portion of the outer container does not have the constituent members of the inner container, that is, the fifth flange portion constituting the outer container is larger than the inner container Since the constituent member (the sixth flange portion or the like) protrudes outside, the separation operation between the inner container and the outer container can be smoothly performed.

According to the invention of [8], the integration strength between the inner container and the outer container can be further increased, and the state in which the two containers are integrated can be made more stable.

According to the invention of the present invention, at least the outer peripheral edge portion of the lower surface of the second flange portion of the inner container does not have the constituent members of the outer container, that is, the second flange portion constituting the inner container is smaller than the outer container. The component (the third flange portion, etc.) protrudes out, so that it can be smoothly The separation of the inner container and the outer container is performed.

According to the invention of [10], since the outer surface material of the inner container and the inner surface material of the outer container are respectively limited to a specific one, the inner container can maintain the shape even in a separated state, and the heat resistance is excellent, and can be sufficiently maintained even if heated in a microwave oven. The shape and the two containers are integrated in a sufficiently separable state.

According to the invention of [11], since the two containers are used in an integrated state before the microwave oven is heated, the outer container contains a metal layer before the microwave oven is heated, and the gas barrier property of the container is excellent, and the food can be protected. Avoid oxygen and moisture infiltration. In addition, when the microwave oven is heated, the two containers are separated, and since only the inner container containing no metal layer is used for heating in the microwave oven, when the microwave oven is heated, sparks are prevented from occurring, and the container is not easily heated, and the heating efficiency of the food is high. And it is not easy to produce uneven heating of food.

According to the invention of [12], since the food container sealed with the food is subjected to heat treatment for sterilization (for example, sterilization sterilization, boiling sterilization, etc.), the food container is cooled after heating at this time. Since the outer container has a metal layer, the heat shrinkage is small. On the other hand, since the inner container is a resin container containing no metal layer, the heat shrinkage is relatively large, and the heat shrinkage is poor. Further, the integration strength between the inner container and the outer container which are integrated with sufficient strength is reduced. Therefore, when the microwave oven is heated, the inner container and the outer container can be easily separated by a human hand.

In other words, when the food container of the present invention is used, the food container is filled with food in the inner container of the food container, and sealed through the opening until the heat sterilization process is completed, and the inner container and the outer container are sufficiently The strength is integrated, and the separation of the two containers can be completely prevented. In addition, after the food is heated and sterilized, when the microwave oven is heated, The inner container and the outer container can be easily separated by a human hand.

1‧‧‧Food containers

2‧‧‧ inside container

2a‧‧‧Bottom wall of the inner container

2b‧‧‧peripheral side wall of the inner container

3‧‧‧Outside container

3a‧‧‧Bottom wall of the outer container

3b‧‧‧Week side wall of the outer container

20‧‧‧ openings

21‧‧‧First flange

22‧‧‧Second flange

23‧‧‧Departure

26‧‧‧ sixth flange

30‧‧‧ openings

33‧‧‧ Third flange

34‧‧‧Fourth flange

35‧‧‧Five flange

36‧‧‧Departure

51‧‧‧First resin layer (inner layer)

52‧‧‧metal layer

53‧‧‧Second resin layer (outer layer)

80‧‧‧Forming sheet

81‧‧‧ bottom rib stamping

82‧‧‧ Die-casting mould

82a‧‧‧Anti-wrinkle surface

83‧‧‧ Punch

84‧‧‧Clip station

85‧‧‧Support (anti-wrinkle)

In the first drawing, a cross-sectional view showing a method of manufacturing the food container of the present invention is shown in the order of steps, and (A) shows a state in which the sheet for molding and the inner container are placed in a stretch molding apparatus, and (B) shows that the sheet is pulled. In the middle of the stretch forming, (C) shows the state in which the stretch forming is completed.

The second drawing (A) is a bottom view of the stretch molding die, and (B) is a bottom view of the inner container before the stretch forming which is prepared (the top view of the inner container in the state of the first figure (A) arrangement).

The third drawing shows a cross-sectional view of an example of a food container obtained by the production method of the present invention.

The fourth figure shows a cross-sectional view showing a state in which the food container of the third drawing is separated into an inner container and an outer container.

Fig. 5 is a cross-sectional view showing another example of the food container obtained by the production method of the present invention.

Fig. 6 is a cross-sectional view showing a state in which the food container of Fig. 5 is separated into an inner container and an outer container.

A method of manufacturing the food container of the present invention will be described with reference to the first drawing. In the first figure, 81 is a bottom rib stamper whose molding surface is shaped to fit the shape of the bottom surface of the outer container 3 on the third side. 82 series die casting mold. The 83 series punch is fixed to the punch table 84. The 85-type support portion (anti-wrinkle portion) is configured such that the molding sheet 80 is interposed between the die-casting mold 82 and the wrinkle-preventing surface 82a. And the bottom rib stamper 81, the die-casting mold 82 (female mold), the punch 83 (male mold), the punch table 84. The support portion (anti-wrinkle portion) 85 constitutes a stretch forming mold.

Then, as shown in the first diagram (A), the inner container 2 is provided on the punch 83. At this time, the bottom wall 2a of the inner container 2 faces upward, and the opening 20 faces downward, and is disposed outside the punch 83 from the upper side. The inner container 2 is manufactured by vacuum molding or injection molding. Next, a molding sheet 80 containing the metal layer 52 is attached to the support portion (anti-wrinkle portion) 85 and the inner container 2. Next, as shown in the first diagram (B), the die-casting mold 82 is moved downward by the surface of the support portion (anti-wrinkle portion) 85 and the wrinkle-preventing surface 82a of the die-casting mold 82 in a circular shape. The peripheral portion of the sheet 80 for molding is further moved downward by the die-casting mold 82. Next, as shown in the first figure (C), by moving the wrinkle-preventing surface 82a further downward to abut against the upper surface of the support portion (anti-wrinkle portion) 85, and also lowering the bottom rib stamper 81, The molding sheet 80 is stretch-molded, and the outer-side container 3 containing the metal layer is molded by the stretch forming, and the outer container 3 is superposed on the outer surface of the inner container 2, whereby the food for the third figure can be obtained. Container 1. In other words, it is possible to produce a food container 1 in which the outer container 3 including the metal layer is superposed on the outer surface of the inner container 2 made of a resin containing no metal layer, and the two containers 2 and 3 are integrated and separable.

In the manufacturing method of the present invention, the outer diameter of the opening portion 20 of the inner container 2 before the stretch molding which is prepared as described above is "X" (mm), and the die-casting mold for performing the stretch forming of the outer container 3 is used. When the inner diameter of the opening of 82 is "Y" (mm) (refer to the first figure (A) and the second figure), at X≧Y

Stretching is important in the form where the relationship is established. By performing stretch forming in a state in which such a relationship is established, the food container 1 in which the inner container 2 and the outer container 3 are integrated with sufficient strength can be manufactured.

(X-Y) is preferably set to a range of 0 mm or more and 10 mm or less, and (X-Y) is preferably set to a range of 0.5 mm or more and 4.0 mm or less.

The manufacturing method of the present invention is produced by stretch forming, and since the heating is not performed during the molding process, the material of the inner surface of the outer container 3 (the material of the surface on which the molding sheet 80 and the inner container 2 abut) can be The outer surface of the inner container 2 is made of the same material or different.

The food container 1 obtained by the production method of the present invention comprises: an inner container 2 made of a resin having no metal layer; and an outer container 3 having at least a metal layer 52; and the outer container 3 is overlapped on the outer surface of the inner container 2 The two containers 2, 3 are stacked and integrated and separable.

Then, since it is manufactured by the above-described manufacturing method, the food container 1 has the following relationship.

In other words, when the two integrated containers are not separated (the heat sterilization treatment step to be described later), the outer diameter of the opening 20 of the inner container 2 in the separated state is set to "E", and the separation is performed. When the inner diameter of the opening 30 of the outer container 3 is set to "F" (refer to the fourth drawing), E ≧ F is provided.

The relationship is established.

The third figure shows an embodiment of the food container 1 obtained by the production method of the present invention. The inner container 2 includes a bottom wall 2a, a peripheral side wall 2b that stands upward from the peripheral edge of the bottom wall 2a, and an opening 20 at an upper end of the peripheral side wall 2b. The outer container 3 includes a bottom wall 3a, a peripheral side wall 3b that stands upward from the peripheral edge of the bottom wall 3a, and an opening 30 at an upper end of the peripheral side wall 3b. In the present embodiment, the bottom wall 2a of the inner container 2 is circular in plan view. The circumferential side wall 2b of the inner container 2 has a substantially cylindrical shape. Further, in the present embodiment, the bottom wall 3a of the outer container 3 has a circular shape in plan view, and the peripheral side wall 3b of the outer container 3 has a substantially cylindrical shape.

The fourth flange portion 34 is extended from the periphery of the opening portion 30 at the upper end of the outer container 3 (the upper end of the peripheral side wall 3b) in the horizontal direction, and extends from the outer periphery of the fourth flange portion 34 toward the upper side. The step portion 36 is provided with a fifth flange portion 35 extending from the upper end of the step portion 36 in the horizontal direction (see the third drawing).

The sixth flange portion 26 is extended from the periphery of the opening portion 20 at the upper end of the inner container 2 (the upper end of the peripheral side wall 2b) in the horizontal direction (see the third drawing).

In the present embodiment, the inner container 2 is an inner container formed of a single resin layer (single layer), and the outer container 3 is formed with a first resin layer (inner layer) 51 on one surface of the metal layer 52, in the metal layer. The other three layers of the second resin layer (outer layer) 53 are stacked on the other side of the 52 to constitute an outer container (see the third drawing).

Then, the outer container 3 is superposed on the outer surface of the inner container 2, and the two containers 2 and 3 are integrated and separable. In other words, the inner surface of the bottom wall 3a of the outer container 3 is placed on the outer surface of the bottom wall 2a of the inner container 2, and the outer container 3 is placed on the outer surface of the outer side wall 2b of the inner container 2. The inner surface of the side wall 3b, the lower surface of the sixth flange portion 26 of the inner container 2 abuts on the upper surface of the fourth flange portion 34 of the outer container 3, and the front edge of the sixth flange portion 26 The inner peripheral surface of the stepped portion 36 disposed on the outer container 3 is abutted, and the outer container 3 is superposed on the outer surface of the inner container 2 in a substantially suitable state, and the two containers 2 and 3 are integrated and separable (refer to The third picture).

Further, the upper surface of the fifth flange portion 35 which is formed on the outer container 3 is not stacked. The constituent members of the aforementioned inner container 2 are stacked. In other words, the fifth flange portion 35 of the outer container 3 is formed so as to protrude from the outer member (the sixth flange portion 26 or the like), and the inner container 2 can be smoothly separated. The separation operation of the outer container 3 at the time. For example, when the fifth flange portion 35 protrudes from the outer outer side container 3 to deform the fifth flange portion 35, air enters between the inner container 2 and the outer container 3, thereby being integrated and separable. The inner container 2 and the outer container 3.

Then, since the food container 1 of the third embodiment is manufactured by the production method of the present invention, when the two integrated containers are separated (previously in the heat sterilization treatment step described later), the inner container in the separated state is placed. The outer diameter of the opening 20 of the second embodiment is "E", and when the inner diameter of the opening 30 of the outer container 3 in the separated state is "F" (see the fourth drawing), it constitutes E≧F.

The relationship is established.

The food container formed by the relationship is formed, and the inner container 2 and the outer container 3 are integrated with sufficient strength. Therefore, the obtained food container 1 can be completely prevented from being separated from the integrated containers 2 and 3 during storage and when the food is filled (excellent separation resistance). Further, after the food container is subjected to heat treatment for sterilization, the heat shrinkage of the inner container and the outer container during cooling is poor, and the integration of the inner container 2 and the outer container 3 integrated with sufficient strength is reduced. The strength, therefore, after the heat sterilization treatment, the inner container 2 and the outer container 3 can be easily separated by a human hand.

The food container 1 having the above configuration is in a state in which the inner container 2 and the outer container 3 are integrated in a state before storage and heating in the microwave oven. However, in this case, since the outer container 3 contains the metal layer 52, the food is The container 1 has excellent gas barrier properties and protects the food from oxygen and moisture.

In addition, when the foodstuff in the foodstuff container containing the foodstuff is heated by a microwave oven (because it has been subjected to heat sterilization treatment), the inner container 2 and the outer container 3 can be easily separated by hand, and only the inside of the food can be loaded. The container 2 is placed in a microwave oven for heating (refer to the fourth drawing). At this time, since the inner container 2 does not contain a metal layer, when the microwave oven is heated, sparks are prevented from occurring, and the container 2 is not easily heated to a high temperature. The heating efficiency is high, and the effect of uneven heating of the food is less likely to occur.

Fig. 5 shows another embodiment of the food container 1 obtained by the production method of the present invention. The inner container 2 includes a bottom wall 2a and a peripheral side wall 2b that stands upward from the peripheral edge of the bottom wall 2a, and an opening 20 is provided at an upper end of the peripheral side wall 2b. The outer container 3 includes a bottom wall 3a and a peripheral side wall 3b that stands upward from the peripheral edge of the bottom wall 3a, and an opening 30 is provided at an upper end of the peripheral side wall 3b. In the present embodiment, the bottom wall 2a of the inner container 2 has a circular shape in plan view, and the peripheral side wall 2b of the inner container 2 has a substantially cylindrical shape. Further, in the present embodiment, the bottom wall 3a of the outer container 3 has a circular shape in plan view, and the peripheral side wall 3b of the outer container 3 has a substantially cylindrical shape.

The first flange portion 21 is extended from the periphery of the opening portion 20 at the upper end of the inner container 2 (the upper end of the peripheral side wall 2b) in the horizontal direction, and a step is extended from the outer peripheral edge of the first flange portion 21 toward the lower portion. The portion 23 is provided with a second flange portion 22 extending from the lower end of the step portion 23 in the horizontal direction (see FIG. 5).

The third flange portion 33 is extended from the periphery of the opening portion 30 at the upper end of the outer container 3 (the upper end of the peripheral side wall 3b) in the horizontal direction (see FIG. 5).

In the present embodiment, the inner container 2 is an inner container formed of a single resin layer (single layer), and the outer container 3 is formed by stacking a first resin layer on one surface of the metal layer 52 (inside) In the side layer 51, three layers of the second resin layer (outer layer) 53 are stacked on the other surface of the metal layer 52 to constitute an outer container (see FIG. 5).

Then, the outer container 3 is superposed on the outer surface of the inner container 2, and the two containers 2 and 3 are detachably integrated. In other words, the inner surface of the bottom wall 3a of the outer container 3 is placed on the outer surface of the bottom wall 2a of the inner container 2, and the outer container 3 is placed on the outer surface of the outer side wall 2b of the inner container 2. The inner surface of the peripheral side wall 3b, the upper surface of the third flange portion 33 of the outer container 3 abuts on the lower surface of the first flange portion 21 of the inner container 2, and the front edge of the third flange portion 33 The inner peripheral surface of the stepped portion 23 disposed on the inner container 2 is abutted, and the outer container 3 is superposed on the outer surface of the inner container 2 in a substantially suitable state, and the two containers 2 and 3 are detachably integrated (refer to Fifth picture).

Further, constituent members of the outer container 3 are not stacked on the lower surface of the second flange portion 22 of the inner container 2. In other words, the second flange portion 22 of the inner container 2 is formed so as to protrude from the outer member 3 (the third flange portion 33 or the like). With this configuration, the inner container 2 can be smoothly separated. The separation operation of the outer container 3 at the time. For example, when the second flange portion 22 protruding from the outer inner container 2 is held to deform the second flange portion 22, air enters between the inner container 2 and the outer container 3, thereby being integrated and separable. The inner container 2 and the outer container 3.

Then, since the food container 1 of the fifth embodiment is manufactured by the production method of the present invention, when the two integrated containers are separated (previously in the heat sterilization treatment step described later), the inner container in the separated state is placed. The outer diameter of the opening portion 20 of the second portion is "E", and when the inner diameter of the opening portion 30 of the outer container 3 in the separated state is "F" (see the sixth drawing), the E ≧ F is formed.

The relationship is established.

The food container formed by the relationship is formed, and the inner container 2 and the outer container 3 are integrated with sufficient strength. Therefore, the obtained food container 1 can be completely prevented from being separated from the integrated containers 2 and 3 during storage and when the food is filled (excellent separation resistance). Further, after the food container is subjected to heat treatment for sterilization, the heat shrinkage of the inner container 2 and the outer container 3 at the time of subsequent cooling is reduced, thereby reducing the inner container 2 and the outer container 3 which are integrated with sufficient strength. The strength of the integration is such that, after the heat sterilization treatment, the inner container 2 and the outer container 3 can be easily separated by a human hand.

The food container 1 having the above configuration is in a state in which the inner container 2 and the outer container 3 are integrated in a state before storage and heating in the microwave oven. However, in this case, since the outer container 3 contains the metal layer 52, the food is The container 1 has excellent gas barrier properties and protects the food from oxygen and moisture.

In addition, when the foodstuff in the foodstuff container in which the foodstuff is loaded is heated by a microwave oven (because it has been subjected to heat sterilization treatment), the inner container 2 and the outer container 3 can be easily separated by hand (refer to Fig. 6), and only the device can be loaded. The inner container 2 of the food is placed in a microwave oven for heating. At this time, since the inner container 2 does not contain a metal layer, when the microwave oven is heated, sparks are prevented from occurring, and the container 2 is not easily heated to a high temperature, and the food is heated. It has high efficiency and is not easy to produce the effect of uneven heating of food.

In the present invention, the thickness of the inner container 2 is preferably set to 0.5 mm to 1.0 mm. The inner container 2 is not particularly limited as long as it is a resin container containing no metal layer, and may be composed of a single layer (single resin layer) or a plurality of layers (a stack of several resin layers). Among them, the inner container made of polypropylene and the inner container made of polyethylene terephthalate have good heat resistance, and therefore are suitable.

The thickness of the outer container 3 should be relatively thin in consideration of the cost surface, but it is determined by the rigidity required for the food container after the food is filled. The thickness of the outer container 3 is preferably set to 0.05 mm to 0.5 mm. The outer container 3 may be composed of only a single layer composed of the metal layer 52, or may be composed of at least a plurality of layers (stacks) of the metal layer 52. The outer side container 3 is configured as the above-described stacked body. For example, the first resin layer 51 may be stacked on one side of the metal layer 52, and the outer side container 3 may be formed by three layers of the second resin layer 53 stacked on the other side of the metal layer 52 ( Refer to the third and fifth figures). When the outer container 3 is required to have high rigidity, for example, CPP (30 μm) / AL (120 μm) / CPP (200 μm), CPP (50 μm) / AL (100 μm), etc. (stacking structure and thickness of each layer) can be exemplified, and it is not necessary. In the case of high rigidity, for example, CPP (30 μm) / AL (40 μm) / Ny (25 μm), PET (25 μm) / AL (60 μm) / PE (30 μm), and the like (stacking configuration and thickness of each layer) can be exemplified.

The metal constituting the metal layer 52 is not particularly limited. For example, in addition to a single metal such as aluminum, iron, copper, silver or ruthenium, an alloy of such a metal, a magnesium alloy, a titanium alloy or the like can be exemplified. Among them, the metal layer 52 is preferably formed of an aluminum layer from the viewpoint of cost. Aluminum is not particularly limited, and a pure aluminum alloy or an 8000 alloy may be used.

Table 1 shows a suitable example of the combination of the material of the inner container 2 and the material of the outer container 3. Further, in the case of the configuration of the outer container, the material described on the left side is a material formed on the inner surface (the surface in contact with the inner container).

In addition, the following abbreviations described in the present specification including Tables 1 and 2 respectively indicate the following materials (layers).

"PP": Polypropylene

"C-PET": crystalline polyethylene terephthalate

"CPP": unstretched polypropylene (film)

"AL": aluminum (foil)

"Fe": iron

"PE": Polyethylene

"Ny": Nylon

"Resin coating": a resin layer formed by coating a resin, and examples of the resin thereof include epoxy resin, epoxy melamine resin, acrylic resin, polyurethane resin, vinyl acetate resin, vinyl chloride-vinyl acetate. Copolymer resin and the like. A resin coating layer is formed by dissolving such a resin in a solvent by coating.

Further, the present invention is an auxiliary structure for further improving the separation resistance between the inner container 2 and the outer container 3. For example, the bottom wall 2a of the inner container 2 and the bottom wall 3a of the outer container 3 may be adhered by an adhesive.

The shape of the food container 1 of the present invention is not particularly limited to the shape of the above-described embodiment, and is not particularly limited as long as it can accommodate the shape of the food. In addition, the shape (top view shape) of the food container 1 as viewed from the plane is not particularly limited, and examples thereof include a perfect circular shape, an elliptical shape, a quadrangular shape (square shape, a rhombic shape, a rectangular shape, etc.), and a regular pentagonal shape. And other regular polygons.

Further, the food container 1 of the present invention is not particularly limited to those manufactured by the above-described production method, and the above-described production method is merely an example.

The food container 1 of the present invention is supplied to a consumer as a final product (product) by the following charging step, sealing step, heat sterilization treatment step, and the like. In other words, after the food (liquid, solid, etc.) is placed in the inner container 2 of the food container 1 in an integrated state, the flange portion (the first flange portion 21, the sixth convex portion) of the inner container 2 The edge portion 26 or the like seals the peripheral edge portion of the lid body to seal the opening portion 20 of the inner container 2. Thereafter, the food container in a sealed state is subjected to heat sterilization treatment. The heating temperature is generally set at 80 ° C ~ 130 ° C. In addition, heat sterilization The time is generally from 10 minutes to 1.5 hours. In addition, the cover body is not particularly limited, and examples thereof include a stacked film formed of a stack of PET/AL/PET/sealant or PET/AL/PET/heat seal paint.

The container for food after the heat sterilization treatment (the food has been placed in the inner container) is heated and then cooled, and the food container is thermally contracted. However, since the outer container has a metal layer, the heat shrinkage is small. On the other hand, since the inner container is a resin container that does not contain a metal layer, the heat shrinkage is relatively large, and the heat shrinkage is poor, and the integration strength of the inner container and the outer container integrated with sufficient strength is reduced. Therefore, when the microwave oven is heated, the inner container 2 and the outer container 3 can be easily separated by a human hand.

In other words, when the food container 1 obtained by the production method of the present invention is used, after the food container is manufactured, the food is filled in the inner container of the food container and the opening is sealed until the heat sterilization process is completed (required) Before the completion of the heat sterilization treatment without separation, it is possible to completely prevent the inner container 2 and the outer container 3 from being separated from each other with sufficient strength, and after the food is heat-sterilized, it can be used when heating the microwave oven. The inner container 2 and the outer container 3 are easily separated by a human hand.

In addition, as described above, heat shrinkage occurs in the food container by the above-described heat sterilization treatment and subsequent cooling, but the shrinkage ratio of the inner container (resin-made container containing no metal layer) is at this time. 0.5% to 3% (0.8% to 1.8% of the PP system). Therefore, the outer diameter of the opening of the inner container (separated state) after heat sterilization and cooling is set to "M", and the inner container (separated state) When the outer diameter of the opening before the heat sterilization treatment is "E", (EM) / E = 0.005 - 0.03

The relationship is established, and the inner cavity before the heat sterilization treatment is obtained from the relationship using the following formula The outer diameter of the opening of the device (separated state) E E=(M/0.995)~(M/0.97)

Therefore, when the outer diameter M of the opening of the inner container (separated state) after the heat sterilization treatment and cooling is measured, the outer diameter E of the opening of the inner container (separated state) before the heat sterilization treatment can be calculated.

Further, similarly, the heat shrinkage is caused in the food container by the heat sterilization treatment and the subsequent cooling, but the shrinkage ratio of the outer container (having the metal layer) is 0.1% to 1% at this time. Therefore, when the inner diameter of the opening of the outer container (separated state) after the heat sterilization treatment and cooling is "K", and the inner diameter of the opening before the heat sterilization treatment of the outer container (separated state) is "F", (FK)/F=0.001~0.01

The relational expression is established, and the inner diameter of the opening of the outer container (separated state) before the heat sterilization treatment is obtained from the relational expression F F = (K / 0.999) - (K / 0.99)

Therefore, when the inner diameter K of the opening of the outer container (separated state) after the heat sterilization treatment and the cooling is measured, the inner diameter F of the opening of the outer container (separated state) before the heat sterilization treatment can be calculated.

When the outer diameter M of the opening of the inner container (separated state) after the heat sterilization treatment and cooling is measured, the outer diameter E of the opening of the inner container (separated state) before the heat sterilization treatment can be calculated, and the heating can be measured. When the inner diameter K of the opening of the outer container (separated state) after the sterilization treatment and the cooling is performed, the inner diameter F of the opening of the outer container (separated state) before the heat sterilization treatment can be calculated, so that the food can be cooled and sterilized. Use container to judge heat sterilization In the pre-treatment state, whether the food container has the constituent elements (the value of E, the value of F, and the value of (E-F)) of the invention of the above [4] or [5].

In the present invention, when the above-mentioned "X", "E", "F", "M", and "K" are obtained, the shape (the plan view shape) of the food container 1 is a perfect circular shape. Next, X, E, F, M, and K in a state in which the container is in a perfect circular shape are respectively indicated. In addition, the planar viewing shape (planar shape) of the food container 1 is the same in the case of an elliptical shape, a quadrangular shape (square shape, a rhombic shape, a rectangular shape, etc.), a regular pentagonal shape, and other regular polygonal shapes. That is, the above-mentioned "X", "E", "F", "M", and "K" do not mean values measured by the shape of the skew viewed from the normal plane.

In addition, when the planar viewing shape (planar shape) of the food container 1 is an elliptical shape, a quadrangular shape (square shape, a rhombic shape, a rectangular shape, etc.), a regular pentagonal shape, or other regular polygonal shape, the above-mentioned "X" "Y", "E", "F", or "M" and "K" all indicate the longest inner diameter. That is, for example, in the case where the plan view shape is a square shape, the "inner diameter" indicates the inner diameter on the diagonal of the square shape.

Example

Next, specific embodiments of the present invention will be described, but the present invention is not particularly limited to the embodiments.

<Example 1>

The food container 1 shown in Fig. 3 is produced by carrying out the production method (see Fig. 1) of the present invention described in the above paragraph. The molding sheet 80 was composed of an unstretched polypropylene film layer (inner layer) (30 μm) / aluminum layer (120 μm) / unstretched polypropylene film layer (outer layer) (200 μm) The outer container sheet is composed of a three-layer stack, and the inner container 2 is formed by using an inner container having a thickness of 0.5 mm formed of polypropylene, and the outer container 3 is formed by stretch-molding the molding sheet 80. At the same time, by superposing the outer container 3 on the outer surface of the inner container 2, the outer container having a thickness of 0.5 mm is overlapped with the outer container 3 having a thickness of 350 μm, thereby manufacturing the two containers 2 and 3 integrally. Separable food container 1. In addition, the opening diameter (inner diameter) of the die-casting mold 82 of the stretch molding die used for the stretch forming of the outer container is 63.4 mm in the opening of the inner container which is prepared by the above-mentioned preparation. The Y system is 63.4 mm, so the value of (XY) is 0.0 mm.

<Example 2>

The food container 1 shown in Fig. 3 was produced in the same manner as in the first embodiment except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (XY) was set to 0.5 mm. .

<Example 3>

The food container 1 shown in the third figure was produced in the same manner as in the first embodiment except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (XY) was set to 1.0 mm. .

<Example 4>

The food container 1 shown in Fig. 3 was produced in the same manner as in the first embodiment except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (XY) was set to 2.0 mm. .

<Example 5>

In addition to changing the opening of the inner container before the stretch forming of the aforementioned preparation The food container 1 shown in Fig. 3 was produced in the same manner as in Example 1 except that the value of (X-Y) was set to 3.0 mm.

<Example 6>

The food container 1 shown in the third embodiment was produced in the same manner as in the first embodiment except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (XY) was set to 4.0 mm. .

<Example 7>

The food container 1 shown in Fig. 3 was produced in the same manner as in the first embodiment except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (XY) was set to 5.0 mm. .

<Comparative Example 1>

A food container was produced in the same manner as in Example 1 except that the outer diameter X of the opening of the inner container before the stretch molding was performed, and the value of (X-Y) was changed to "-1.0 mm".

Each of the food containers obtained as described above is evaluated in accordance with the following "formability evaluation method", "adhesion evaluation method", and "pre-separation evaluation method before heat sterilization treatment". In addition, the obtained food containers were heat-treated at a temperature corresponding to the heat sterilization treatment, and evaluated according to the following "Ease of Ease Susceptibility Evaluation Method after Heat-sterilization Treatment". These results are shown in Table 2.

<Formability Evaluation Method>

The inner container and the outer container of the food container obtained were evaluated as "○" without breaking or wrinkles, and the container was evaluated as "○". Although the container was shallow, there was no breakage or wrinkles, but when the depth of the container was deep, occasionally, the fracture or wrinkle was evaluated. For "△", it was found that the person who was broken or creased was evaluated as "X".

<Adhesion evaluation method>

When the inner container and the outer container are sufficiently integrated, the evaluation is "○", and the inner container and the outer container are integrated, and the user can evaluate it as "△". The insufficient strength of the inner container and the outer container is evaluated as "x".

<Anti-separation evaluation method before heat sterilization treatment>

It can be evaluated as "X" by a person who can easily be separated by a person, and "△" if it is not a person who can't be separated by a small amount of force. If the person's hand is not separated, it is evaluated as "○".

<Evaluation method for separation ease after heat sterilization treatment>

The obtained food container was taken out in a thermostatic chamber at 100 ° C for 10 minutes, taken out, and naturally cooled in a room at 25 ° C. After 24 hours, the separation property of the food container was manually evaluated. Those who can easily be separated by hand without difficulty can be evaluated as "○", those who are separated by hand can be evaluated as "△", and those who are difficult to separate by hand are evaluated as "X".

As is apparent from Table 2, the food containers of Examples 1 to 7 of the present invention are excellent in moldability, are free from breakage, and the like, and are excellent in gas barrier properties. Further, the food containers of the first to seventh embodiments of the present invention can be completely prevented from being separated before the heat sterilization treatment is required, and the inner container and the outer container can be easily separated by hand after the heat sterilization treatment.

On the other hand, the food container of the comparative example 1 can be easily separated at the stage before the heat sterilization treatment, and the inner container and the outer container may be separated during storage or when the food is loaded.

[Industrial Availability]

The food container of the present invention is not particularly limited, and can be used, for example, as a food container for a food such as a liquid food such as soup or porridge or a solid food such as fish meat or vegetable food. When the foodstuff in the foodstuff container of the present invention in which the food is placed is heated in a microwave oven, the inner container and the outer container are separated, and only the inner container filled with the food is placed in a microwave oven for heating.

The present application claims the priority of Japanese Patent Application No. 2014-143411, the entire disclosure of which is incorporated herein.

The terms and descriptions used herein are for describing embodiments of the invention, and the invention is not limited thereto. The present invention is within the scope of the patent application, and the design is allowed to be changed without departing from the spirit thereof.

2‧‧‧ inside container

3‧‧‧Outside container

80‧‧‧Forming sheet

81‧‧‧ bottom rib stamping

82‧‧‧ Die-casting mould

82a‧‧‧Anti-wrinkle surface

83‧‧‧ Punch

84‧‧‧Clip station

85‧‧‧Support (anti-wrinkle)

Claims (12)

A method for producing a food container, comprising: preparing a resin-made inner container containing no metal layer; and molding a sheet containing at least a metal layer; and stretching the formed sheet by molding And the outer container is molded while the outer container is superposed on the outer surface of the inner container, so that the two containers are detachably integrated; and the outer diameter of the opening of the inner container before the stretch forming is prepared. When the inner diameter of the opening of the die-casting mold of the stretch molding die used for the stretch forming of the outer container is "Y", the relationship of X≧Y is established. The method for producing a food container according to claim 1, wherein a relationship of 0 mm ≦ (X-Y) ≦ 10 mm is established. The method for producing a food container according to claim 1, wherein a relationship of 0.5 mm X (X-Y) ≦ 4.0 mm is established. A food container comprising: a resin inner container having no metal layer; and a container having at least a metal layer; the outer container is superposed on the outer surface of the inner container, and the two containers are detachably integrated When separating the two integrated containers, the opening of the inner container in the separated state When the outer diameter is "E" and the inner diameter of the opening of the container outside the separation state is "F", the relational expression of E ≧ F is established. For example, the food container of claim 4, wherein the relationship of 0 mm ≦ (E-F) ≦ 10 mm is established. The food container according to the fourth or fifth aspect of the invention, characterized in that the fourth flange portion is extended from the periphery of the opening of the upper end of the outer container toward the horizontal direction, and the fourth flange portion is provided. a stepped portion extending toward the upper side of the outer peripheral edge, and a fifth flange portion extending from the upper end of the stepped portion toward the horizontal direction; and a sixth convex portion extending from the periphery of the opening portion of the upper end of the inner container toward the horizontal direction a lower portion of the sixth flange portion abutting against an upper surface of the fourth flange portion of the outer container, wherein the front edge of the sixth flange portion abuts against the inner circumferential surface of the step portion of the outer container . The food container according to claim 6, wherein at least the outer peripheral edge portion of the upper surface of the fifth flange portion of the outer container does not have the constituent members of the inner container. The food container according to the fourth or fifth aspect of the invention, characterized in that the first flange portion is extended from the periphery of the opening portion of the upper end of the inner container toward the horizontal direction, and the first flange portion is provided. a slit portion extending toward the lower side of the outer peripheral edge, and a second flange portion extending from the lower end of the step portion toward the horizontal direction; and a third protrusion extending from the periphery of the opening portion of the upper end of the outer container toward the horizontal direction The upper surface of the third flange portion is abutted against the lower surface of the first flange portion of the inner container, and the front edge of the third flange portion abuts against the inner container The inner peripheral surface of the step. The food container according to claim 8, wherein at least the outer peripheral edge portion of the lower surface of the second flange portion of the inner container does not have the constituent members of the outer container. The food container according to the fourth or fifth aspect of the invention, wherein the outer surface of the inner container is made of polypropylene or crystalline polyethylene terephthalate; and the inner surface of the outer container is made of polypropylene. , polyethylene, nylon, epoxy resin, epoxy melamine resin, acrylic resin, urethane resin, vinyl acetate resin or aluminum. The food container according to claim 4 or 5, wherein the two containers are used in an integrated state before heating in a microwave oven, and when the microwave oven is heated, the two containers are separated, and only the inner container is used. It is heated by a microwave oven. A method for producing a double container filled with food, comprising: a step of loading food into an inner container of a food container in an integrated state in the fourth or fifth aspect of the patent application; a step of bonding the lid to seal the opening of the inner container; and a step of heat-sterilizing the sealed food container.