JP2013005808A - Method for producing storage body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage body that can suppress generation of a drip even when wrapping an object to be frozen during magnetic field-applied freezing, and to provide a method for producing the storage body storing the object to be frozen.SOLUTION: The storage body is made of a material whose surface resistance is 1.3 × 10Ω/SQUARE or less, or which is obtained by compounding a prescribed polymer and potassium-ionomer and has 19% or more of the compounding ratio of the potassium-ionomer, and is used during magnetic field-applied freezing.

Description

  The present invention relates to a storage body and a method for producing a storage body that stores a frozen product. In particular, the present invention relates to a technique of freezing while applying an electric field or a magnetic field to an object to be frozen.

  When freezing a frozen object such as food or an organ, a technique for freezing while applying an electric field or a magnetic field to the frozen object (hereinafter referred to as “applied freezing”) is known (see, for example, Patent Documents 1 to 6). . According to applied refrigeration, it has been confirmed that a liquid (hereinafter referred to as “drip”) leached when cells are destroyed becomes difficult to be discharged when thawed. If the drip does not come out, the object to be frozen will not be damaged by cold thawing. Therefore, in the case of food, the flavor and texture are not impaired. In the case of an organ, it can be stored in a state suitable for transplantation.

WO2005 / 013730 Japanese Patent No. 397429 Japanese Patent No. 4041673 JP 2003-088347 A JP 2004-081133 A JP 2004-081134 A

  The problem with the above-described technique is that if the product is frozen after being vacuum-packed, a drip will be generated when it is thawed even though it is frozen by application. In the first place, when frozen food is distributed, it is often vacuum-packed with a transparent film or the like. Therefore, it is possible to choose between vacuum packaging and freezing, or freezing and vacuum packaging. However, if it is vacuum-packed after freezing, thawing may progress during that time. Also, it is not desirable in terms of hygiene.

Therefore, it is desirable to freeze after vacuum packaging. However, if it is frozen after being vacuum-packed, a drip will come out at the time of thawing in spite of the applied freezing.
In view of the above-described problems, the present invention provides a storage body that can suppress the occurrence of drip at the time of thawing even when the object to be frozen is frozen in a state of being stored in the storage body, and a freezing using the storage body. It aims at providing the method of producing the storage body which stored goods.

The invention described in claim 1 made to achieve the above object is a storage body having a storage space as a space for storing a storage object, the inner surface of the storage body forming a boundary of the storage space The surface resistance is set to 1.3 × 10 ¹⁰ Ω / □ or less.

  The invention according to claim 2 is a storage body having a storage space as a space for storing a storage object, wherein at least an inner surface of the storage body forming a boundary of the storage space has a predetermined polymer. A material in which a substance and a potassium ionomer are blended, wherein the blending ratio of the potassium ionomer is 19% or more.

The invention according to claim 3 is the storage body according to claim 1 or claim 2 in which a frozen product or an unfrozen frozen object is stored as the storage object.
According to these inventions (Inventions 1 to 3), it is possible to prevent the occurrence of drip at the time of thawing by applying freezing. The reason will be described in Examples.

  The production method of the storage body storing the frozen product according to any one of claims 4 to 9 uses the techniques of Patent Documents 1 to 6. That is, after storing an unfrozen frozen object in the storage body of the present invention, the frozen object is frozen to make a frozen product, thereby producing a storage body containing the frozen product. The effect is that drip can be prevented from occurring during thawing. Specifically, it is as follows.

  The method for producing a storage body according to claim 4 includes a first step, a second step, and a third step. In a 1st process, the storage body of Claim 1 or Claim 2 which accommodated the unfrozen frozen target object as a storage target object is mounted in an electroconductive mounting board. In a 2nd process, the frozen object accommodated in the storage body mounted in the mounting board is cooled in the state which applied the alternating voltage and the DC voltage to the mounting board simultaneously. In the third step, after the second step is completed, the object to be frozen stored in the storage body mounted on the mounting plate is frozen while only the AC voltage or the DC voltage is applied to the mounting plate.

  The method for producing a storage body according to claim 5 includes a first step and a second step. In a 1st process, an alternating electric field and / or a magnetic field are made to act on the storage body of Claim 1 or Claim 2 which stored the unfrozen frozen target object as a storage target object. In the second step, the object to be frozen stored in the storage body is frozen by applying cold air to the storage body to which an alternating electric field and / or magnetic field is applied.

  Specifically, in the second step, the wind direction and the air volume are adjusted so that the cold air is rectified into a parallel flow, and the rectified cold air is further sucked and re-rectified to be additionally blown at a uniform flow rate and flow rate. This is the step of supplying cold air rectification. In the first step, when an alternating electric field is applied, the electric field energy having a frequency of 50 kHz to 5 MHz can be continuously scanned, or the electric field energy whose frequency is changed stepwise can be scanned, while the magnetic field is applied. Sometimes, a step of applying a static magnetic field and / or a variable magnetic field by an electromagnetic coil disposed so as to surround, sandwich, or straddle a holder that holds an object to be frozen through a container. is there.

  The method for producing a storage body according to claim 6 includes a first step and a second step. In the first step, the ambient temperature of the storage body is set to −100 ° C. while applying a unidirectional magnetic field to the storage body according to claim 1 or 2, which stores an unfrozen frozen object as the storage object. Cool to ~ -30 and freeze quickly. In the second step, the object to be frozen stored in the storage body is cooled by applying cold air of 1 to 5 m / sec to the storage body, and sound waves in an audible frequency band are superimposed on the cold air.

  The magnetic field in one direction fluctuates and fluctuates in a predetermined range in the positive and negative directions with respect to the reference and at a frequency of 50 or 60 Hz with respect to an arbitrary fixed value in the range of 1 to 20000 Gs. is there.

  The method for producing a storage body according to claim 7 includes a first step and a second step. In the first step, as a storage object, a frozen object stored in the storage body is held by a holder via the storage body according to claim 1 or 2 in which an unfrozen frozen object is stored. To do. In the second step, the object to be frozen stored in the storage body is frozen by applying an alternating electric field and a magnetic field to the storage body and applying cold air to the storage body.

Specifically, the alternating electric field applied in the second step is an alternating electric field whose frequency is continuously changed in the frequency range of 50 Hz to 5 MHz. Further, the magnetic field to be applied in the second step is so as to straddle the holder holding the object to be frozen, sandwich the holder holding the object to be frozen, or surround the holder holding the object to be frozen, It is a static magnetic field and / or a fluctuating magnetic field generated by a dielectric coil provided so as not to disturb cold air.

  The method for producing a storage body according to claim 8 includes a first step and a second step. In the first step, as a storage object, a frozen object stored in the storage body is held by a holder via the storage body according to claim 1 or 2 in which an unfrozen frozen object is stored. To do. In the second step, the object to be frozen stored in the storage body is frozen while a static magnetic field and a variable magnetic field are applied to the storage body.

  The static magnetic field is 1 to 10000 Gs. Further, the variable magnetic field is generated by a plurality of electromagnetic coil structures that generate a variable magnetic field of 0.1 to 1000 Gs by energizing alternating current. And the electromagnetic coil structure is parallel to the holding tool for holding the object to be frozen or to surround the holding tool for holding the object to be frozen, and the plurality of electromagnetic coil structures are parallel to the holding tool. They are arranged so as to be orthogonal or crossed.

  The method for producing a storage body according to claim 9 includes first to seventh steps. In the first step, an unfrozen object to be frozen is aged in a dielectric CAS aging in an atmosphere of a temperature of 2 to 15 ° C. and a relative humidity of 98 to 100% under the action of a static magnetic field and a variable magnetic field or an alternating electric field. Apply processing. In the second step, a frozen object subjected to dielectric CAS ripening treatment is dipped and added to dielectric CAS magnetic water obtained by applying a static magnetic field and a variable magnetic field or further an alternating electric field to flowing water having a flow velocity of 2 m / s or more.

  In the third step, the frozen object processed in the second step is drained. In the fourth step, the object to be frozen processed in the third step is subjected to a dielectric CAS drying process in which the object to be frozen is dried in a reduced pressure atmosphere at a temperature of 2 to 15 ° C. under the action of a static magnetic field and a variable magnetic field. In the fifth step, the object to be frozen subjected to the fourth step is stored in the storage body according to claim 1 or claim 2.

  In the sixth step, the object to be frozen stored in the storage body is cooled to a temperature of −60 ° C. to 0 ° C. while applying a static magnetic field and a varying magnetic field or an alternating electric field to the storage body. In the seventh step, a dielectric CAS freezing process is performed in which the object to be frozen stored in the storage body subjected to the sixth step is quickly frozen at the temperature cooled in the sixth step.

  That is, Claims 4 to 9 freeze the unfrozen object to be frozen stored in the storage body described in Claim 1 or Claim 2 by using the techniques described in Patent Documents 1 to 6. Is. Conventionally, there has been a problem that when the object to be frozen is frozen by the techniques described in these documents in a state in which the object to be frozen is stored in a storage body, a drip is generated at the time of thawing. However, by using the storage body of the present invention, it is possible to avoid the occurrence of drip during freezing even if the frozen object is frozen by these techniques in a state where the frozen object is stored in the storage body. Can do.

  Similarly to claims 4 to 9, other inventions described in claims of Patent Documents 1 to 6 or other conventional techniques related to applied refrigeration may be used. For example, proton (registered trademark) freezing (see, for example, “Utility Model No. 3126049” and “JP2007 / 000845”) may be used.

Regarding the contents of Japanese Patent Application Laid-Open No. 2003-088347, a procedure amendment (dissatisfaction 2007-27178: submitted on November 5, 2007) was also referred to. Similarly, regarding the contents of Japanese Patent Application Laid-Open No. 2007-060915, a procedure amendment (Japanese Patent Application No. 2002-248571: filed on October 19, 2007) was also referred to.

The figure showing the storage bag 100 and the frozen object 200. FIG. 1 is a block diagram of a surface voltage measuring device 1. FIG. The table which shows the characteristic and freezing effect of each film. The graph showing the relationship between a measurement voltage and a KI addition rate. The graph showing the relationship between measurement voltage and surface resistance.

Hereinafter, it demonstrates with drawing.
[Bag structure]
FIG. 1 is a diagram showing a storage bag 100 to which the present invention is applied and an unfrozen frozen object 200 stored in the storage bag 100. FIG. 1A shows the storage bag 100. FIG. 1B shows a state in which the frozen object 200 is stored in the storage bag 100. FIG. 1C shows a state where the storage opening of the storage bag 100 storing the object 200 to be frozen is sealed and the object 200 to be frozen is vacuum-packed. In the present embodiment, the storage bag 100 storing the unfrozen frozen object 200 is made in this way.

In order to prevent a drip from being generated during thawing even when the object to be frozen is stored while the object to be frozen is stored in the storage bag 100, the storage bag that forms the boundary of the space in which the object to be frozen is stored is formed. The surface resistance of the inner surface of 100 may be set to 1.3 × 10 ¹⁰ Ω / □ or less. The unit Ω / □ of the surface resistance used here is also expressed as “Ω / sq” and represents the electric resistance per unit area. This unit is based on the JIS standard.

Hereinafter, if the surface resistance of the inner surface of the storage bag 100 is set to 1.3 × 10 ¹⁰ Ω / □ or less, drip can be prevented by giving a plurality of examples of the composition of the sheet constituting the storage bag 100, It demonstrates with an experimental result (Example 1- Example 6).
[Example 1]
[Bag composition and manufacturing method]
In Example 1, the storage bag 100 is made of a potassium-ionomer (KI) blend film.

The potassium ionomer (KI) blend film is obtained by blending LLDPE (Linear Low Density Polyethylene) with KI (potassium ionomer). Since the present inventors have examined the presence or absence of drip generation by changing the addition rate of KI by experiment, in the following, the case where the addition rate of KI is 20% is particularly [1-A]. 30% is expressed as [1-I], 40% is expressed as [1-U], and 100% is expressed as [1-e].

KI used was Entira (registered trademark) manufactured by Mitsui DuPont Polychemical Co., Ltd. The main property is that when it is added to a predetermined polymer substance such as polyolefin (LLDPE in this embodiment), it has an effect of lowering electric resistance.
[Surface voltage measurement experiment]
FIG. 2 shows a block diagram of the surface voltage measuring apparatus 1. The surface voltage measuring device 1 includes a freezer 10, an insulating support 20, a tray 30, a DC power supply 40, and a voltmeter 50. The freezer 10, the DC power source 40, and the voltmeter 50 are grounded. Since the tray 30 is metallic, it is electrically conductive and is placed on the insulating support 20. Further, the DC power supply 40 is connected to the tray 30 by a conducting wire so that a voltage can be applied to the tray 30.

  In the experimental method, first, the above-described film is placed on the insulating support portion 20 in the form of a single film instead of a bag. While applying 2000 V to the tray 30 by the DC power source 40, the voltage on the ground surface on the surface (measurement surface) opposite to the surface (tray surface) in contact with the tray 30 of the film placed on the tray 30 is measured. Measure with a voltmeter 50. In addition, since it is necessary to experiment with the door of the freezer 10 opened, the inside of the freezer 10 is experimented at room temperature.

The result is shown in the measurement value column in the right column of FIG. As shown in FIG. 3, [1-A]: 420V, [1-I]: 730V, [1-U]: 900V, [1-E]: 1800V.
FIG. 4 is a graph showing the measurement results. The vertical axis represents the measurement voltage (V), and the horizontal axis represents the addition rate (%) of KI. It can be seen from the graph that both have a strong positive correlation and that the experimental value can be approximated by a straight line.
[Surface resistance measurement experiment]
The result of having measured surface resistance (ohm / square) about the film mentioned above is shown. The value of this surface resistance was measured by a usual method using a commercially available apparatus. Specifically, "HIRE" manufactured by Mitsubishi Electric Corporation
STA UP ”was measured under the conditions of 500 V, 10 seconds, 23 ° C., and 50% humidity.

This result is shown in the surface resistance column in the right column of FIG. As shown in FIG. 3, [1-A]: 2 × 10 ¹⁰ Ω / □, [1-I]: 4 × 10 ⁹ Ω / □, [1-C]: 3 × 10 ⁹ Ω / □, [1 -D]: 1 × 10 ⁸ Ω / □.

FIG. 5 shows the measurement results in a graph in which the vertical axis represents measurement voltage (V) and the horizontal axis represents surface resistance (Ω / □). In addition, the value of surface resistance is displayed by the logarithm. From this graph, it can be seen that there is a strong negative correlation between the measured voltage (V) and the surface resistance (Ω / □), and the experimental value can be approximated by a straight line.
[Freezing-thawing experiment]
The procedure of the freeze-thaw experiment will be described. First, the above-described film is made into a bag 100 as shown in FIG. Then, as shown in FIG. 1 (b), a living dolom (anchovy fry) is placed in the bag 100 as a frozen object 200. Dorome was chosen because it is known to be particularly difficult to preserve frozen. And as shown in FIG.1 (c), the bag containing a dolome is deaerated packaging seal, ie, vacuum-packed, with a vacuum packaging machine.

  Then, the dolome that has been deaerated and package-sealed is frozen at −20 ° C. for two and a half hours using the refrigeration apparatus described in WO2005 / 013730. The refrigeration apparatus will be briefly described. The refrigeration apparatus has substantially the same configuration as the surface voltage measurement apparatus 1. However, a voltmeter is not required, and a fan for circulating the air inside the apparatus and an AC power supply configured to apply an AC voltage to the tray are provided.

  And DC voltage -2000V and alternating voltage 60Hz * 1750V are applied to a tray. Then, it transfers to a normal freezer and freezes at -20 degreeC over 1 month. And it is made to thaw naturally at room temperature, and the freezing effect is measured by the presence or absence of drip.

The result is shown in the freezing effect of FIG. ○ indicates no drip, and Δ indicates a slight drip. From FIG. 3, it can be said that if the surface resistance is 4 × 10 ⁹ Ω / □ or less, the refrigeration effect is marked with ○. Furthermore, in order to reduce the surface resistance to 4 × 10 ⁹ Ω / □ or less, the addition rate of KI is 30%.
It can be said that the above is sufficient.

That is, according to this experiment, when at least the storage bag 100 is made of a potassium-ionomer (KI) blend film, the addition rate of KI is adjusted so that the surface resistance is 4 × 10 ⁹ Ω / □ or less. It can be said that a drip can be prevented by adjusting.

Further, even if the storage bag 100 is not composed of a potassium-ionomer (KI) blend film, it is possible to prevent drip and the storage bag 100 even if the surface resistance is not less than 4 × 10 ⁹ Ω / □. Example 2 to Example 6 will explain that drip can be prevented by setting the surface resistance of the inner surface to 1.3 × 10 ¹⁰ Ω / □ or less.
[Examples 2 to 6]
From here, Example 2-Example 6 are described. However, the storage bag 100 used in Example 2 to Example 4 has a composition different from that of Example 1 and the bag structure is the same, and therefore description of the structure of the bag is omitted. On the other hand, Example 5 and Example 6 form the storage box instead of the storage bag 100 (detailed later). Moreover, there is no result of the surface voltage measurement experiment in any of the examples.
[Bag composition and manufacturing method]
[Example 2]
In Example 2, the storage bag 100 is composed of a multilayer film composed of a KI blend film and a biaxially stretched nylon laminated film.

  That is, the container of Example 2 has a three-layer structure in which LLDPE + (KI) is the first layer, LLDPE is the second layer, and biaxially stretched Ny (Nylon: nylon) is the third layer. The total thickness of the first layer and the second layer is set to 50 μm, and the thickness of the third layer is set to 15 μm.

  The manufacturing method of this multilayer film is as follows. First, LLDPE + (KI) / LLDPE is made by coextrusion. Then, the coextruded LLDPE + (KI) / LLDPE and biaxially stretched Ny are dry laminated to complete. In addition, in the experiment described later, since the addition rate of KI is 0% and the addition rate of KI is 20%, KI in LLDPE + (K-I) is used below. A case where the addition rate is 0% is referred to as [2-A], and a case where the addition rate of KI is 20% is referred to as [2-A].

In Example 2, when the storage bag 100 is made by heat sealing, the first layer is made to be the inner surface of the bag. The other embodiments are the same for those having a plurality of layers.
[Example 3]
The storage bag 100 of Example 3 is made of a single layer film of CPP (unstretched polypropylene). Since this CPP single layer film is a well-known one, description of the manufacturing method and the like will be omitted. In the experiment described below, a 20 μm thickness and a 40 μm thickness are used. In the following, a 20 μm thick [3-a] and a 40 μm thick [ 3-i].
[Example 4]
In the storage bag 100 of Example 4, the first layer is composed of Al vapor deposition, and the second layer is composed of a CPP film. Since this multilayer film is also well known, details thereof are not specifically described. In the experiment described later, a thickness of 20 μm including Al vapor deposition and a thickness of 40 μm including Al vapor deposition are used. Therefore, in the following, the thickness including Al vapor deposition is 20 μm. Is referred to as [4-A], and a thickness of 40 μm is referred to as [4-I].
[Example 5]
The fifth embodiment uses a storage box instead of a bag as a storage body. The composition of the entire storage box is as follows: the first layer is Al vapor deposition, the second layer is a PP (polypropylene) film, the third layer is a PP laminated layer (polypropylene laminate layer), and the fourth layer is PP + (K-I). Consists of multilayer film. The total thickness of the first layer and the second layer is 20 μm, the thickness of the third layer is 20 μm, and the thickness of the fourth layer is 500 μm.

The manufacturing method of this multilayer film is as follows. That is, using PP + (KI) as a base material, an Al-deposited PP film is sandwich-laminated so that the Al-deposited surface is on the outside via a PP laminate layer. In addition, in the experiment described later, those with Al deposition and those without Al deposition are used. Therefore, in the following, those with Al deposition are [5-a], and those without Al deposition are [5-i]. Call it. Then, the produced film is compressed and formed into a container shaped like a lunch box without the lid.
[Example 6]
The sixth embodiment also uses a storage box instead of a bag as a storage body. The composition of the entire storage box is composed of a multilayer film in which the first layer is a PP film, the second layer is Al deposited, the third layer is a PP laminated layer, and the fourth layer is PP + (K-I). The total thickness of the first layer and the second layer is 20 μm, the thickness of the third layer is 20 μm, and the thickness of the fourth layer is 500 μm.

The manufacturing method of this multilayer film is as follows. That is, the PP film deposited with Al is sandwich-laminated using PP + (KI) as a base material, with the Al vapor deposition surface facing inside through the PP laminate layer. In addition, in the experiment described later, those having Al vapor deposition and those having no Al vapor deposition are used. Therefore, in the following, those having Al vapor deposition are [6-a], and those having no Al vapor deposition are [6-i]. Call it. Then, the produced film is compressed and formed into a container shaped like a lunch box without the lid.
[Surface resistance measurement experiment]
The experimental method is almost the same as that described in Example 1. However, with respect to those having a plurality of layers, the surface opposite to the first layer was placed in contact with the tray 30, and the voltage of the surface of the first layer was measured. As shown in FIG. 3, the results are as follows: [2-A]: 320V, [2-I]: 500V, [3-A]: 430V, [3-I]: 330V, [4-A]: 520V, [4 -I]: 330V, [5-A]: 1930V, [5-I]: 420V, [6-A]: 600V, [6-I]: 420V.
[Freezing-thawing experiment]
The experimental method is the same as that described in Example 1 in Examples 2 to 4. On the other hand, in Example 5 and Example 6, after putting the object to be frozen in the storage box, the lid is made of an OPP (biaxially stretched polypropylene) film on which aluminum is vapor-deposited with the aluminum vapor-deposited surface inside. The results are as shown in FIG. In addition, (circle) shows that there is no drip, (triangle | delta) has some drip, and x has drip. Indicates that the texture and flavor were particularly close before thawing in addition to the absence of drip. [2-A]: ×, [2-I]: ○, [3-A]: Δ, [3-I]: ×, [4-A]: ○, [4-I]: ×, [5 -A]: ◎, [5-I]: Δ to ○, [6-A]: ○, [6-I]: Δ to ○.

What can be said from the results of Examples 2 to 6 is that there is a close relationship between the results of the surface voltage measurement experiment and the refrigeration effect. Specifically, if the measured voltage value is 500 V or more, the refrigeration effect is marked with ◯. Furthermore, if it is 1930V, ◎ is attached.
[Discussion]
The results of Examples 2 to 6 are applied to Example 1. In other words, if the result of the surface voltage measurement experiment is 500 V or more, good results are obtained in Examples 2 to 6. Therefore, according to these experimental results, the graphs of FIGS. 4 and 5 are used. The numerical limitations relating to the surface resistance and KI addition rate described in Example 1 can be expanded.

  In the graph shown in FIG. 4, the addition rate of KI corresponding to the measurement voltage 500V is 19%. Therefore, in the case of a single layer film of LLDPE + (KI), it can be said that the refrigeration effect peculiar to the present invention can be obtained if the addition rate of KI is 19% or more. Since LLDPE is an insulator, it hardly contributes to electrical conduction. Therefore, even if mixed with polyolefins other than LLDPE, if KI is blended at least 19%, the same result as in this example should be obtained.

In the graph shown in FIG. 5, the value of the surface resistance corresponding to the measurement voltage 500V is 1.3 × 10 ¹⁰ Ω / □. Therefore, in order to obtain the freezing effect peculiar to the present invention, a film having a surface resistance of 1.3 × 10 ¹⁰ Ω / □ or less may be used.

  Of course, from the results of [Example 2] and [Example 4], it can be said that there is a negative correlation between the film thickness and the surface voltage. Therefore, it is expected that the smaller the resistance value (volume resistance) in the film thickness direction, the higher the surface voltage and the better the refrigeration effect.

  However, what can be considered from the results of Example 5 and Example 6 is that surface resistance is more dominant than refrigeration effect rather than volume resistance. That is, the volume resistance does not affect the value whether the Al deposition surface is inside or outside. On the other hand, the value of the surface resistance varies greatly depending on whether the Al deposition surface is internal or external.

The experimental result of the refrigeration effect is that there is no Al vapor deposition <Al vapor deposition (inside) <Al vapor deposition (external), so a strong relationship between the refrigeration effect and the surface resistance is estimated.
[Other experimental results]
Similar results were obtained with mackerel, squid and tuna. Therefore, it can be said that the effect obtained by the present invention can be applied not only to Dorome but also to various fresh foods.
[Examples 7 and 8]
An additional experiment was conducted using a box as the container.
[Box composition and manufacturing method]
[Example 7]
A film having a thickness of 0.5 mm blended with PP (polypropylene) + (K-I) is formed by pressure forming to make a container like a lunch box without the lid. In the experiment described later, KI addition rates of 20%, 30%, 40%, and 100% are prepared (4 types in total). Then, an OPP (biaxially stretched polypropylene) film deposited with aluminum is used as a lid.
[Example 8]
PP: 80% + (KI): Blended at 20% and aluminum vapor-deposited CPP film are made into a laminated film by the PP extrusion lamination method. At this time, the aluminum deposition surface should be on the outside. Then, this laminated film is formed into a lunch box shape with the lid removed by pressure forming so that the aluminum vapor deposition surface is inside. And the OPP film vapor-deposited with aluminum is used as a lid.
[Freezing-thawing experiment]
As frozen objects, nigiri (squid, Thai, tuna, sweet shrimp), sashimi (tuna, flounder), and boiled vegetables were used. We chose fresh seafood. Then, any one of the objects to be frozen was put into the containers described in Example 7 and Example 8, and the aluminum vapor deposition surface was placed inside. And it frozen under the same conditions as Examples 1-6. Then, it thawed naturally at room temperature.

As a result, the refrigeration effect was good in both cases of Example 7 and Example 8. In other words, almost no drip was seen, and the flavor and texture were almost the same as before freezing.
[Disadvantages caused by high voltage application]
From the results of Examples 1 to 8, it is estimated that a freezing effect can be obtained if a voltage is applied to the food. If so, it is expected that the refrigeration effect as described above can be obtained if a high voltage is applied even if the food is wrapped. However, various disadvantages occur when a high voltage is applied. It has been confirmed that this does not depend on the electrical properties of the film.

For example, when 3500 V is applied, a phenomenon that the odor of the food disappears after thawing occurs. Since the peculiar odor which a foodstuff has is considered to be a part of taste, the objective of preventing it from becoming tasteless by cold thawing cannot be achieved.

When the applied voltage is further increased to 5000V and 10000V, the cells are destroyed, and the food does not retain its original shape, which is out of the question.
[Others]
As described in Patent Document 1 (WO2005 / 013730), the voltage to be applied may be changed for each food.

Biaxially stretched Ny / PE / (PE / PE + KI coextruded film), a three-layer sheet made by sandwich lamination, may be used.
Glycerol may be added to the layer constituting the inner surface of the container. This is because glycerin has a hydroxyl group and thus has an effect of reducing surface resistance.

  Further, the blending ratio of KI in the layer in contact with the food is desirably 50% or less. This is because the food safety guarantee range is exceeded. Although it is not dangerous, it will exceed the FDA conformance and PL registration scope. More preferably, it is 30% or less. This is because film formation becomes difficult if the KI compounding ratio is too high.

When using LLDPE in which higher α-olefins (C ₅ , C ₆ , C ₈ or more) are copolymerized with polyethylene blended with KI, especially LLDPE having a narrow molecular weight distribution during single-stage polymerization using a metallocene catalyst, A KI formulation with little reduction in seal strength is obtained. The narrow molecular weight distribution means that, for example, the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) determined by GPC is 3.5 or less.

Particularly recommended is LLDPE having a density of 0.925 g / cm ³ or less using a higher α-olefin comonomer using a metallocene catalyst. This is because film strength and good heat sealability can be obtained. The MLD of LLDPE has a preferable range for each machine for forming a film. However, since it does not affect the effect of the applied refrigeration for the intended use, it is only necessary to select an MFR resin that is suitable for molding equipment and is compatible with KI.

  LDPE (high pressure method / low density polyethylene) may also be used. A copolymer resin using a comonomer such as vinyl acetate, acrylic acid, or methacrylic acid may be used with a peroxide as a polymerization initiator.

  The outermost layer of the composite film may be anything as long as it can protect the contents and can be vacuum packaged. The barrier interlayer film used in the prior art may or may not be used.

  Further, it is considered that the same effect as in Examples 1 and 2 can be obtained even if the resin itself is a film made of a conductive resin. For example, silicon resin or conductive ink. However, it can be said that none of them is suitable for use in contact with food, at least at the time of filing. This is because no safety evaluation or safety approval has been made for substances that come into contact with food. If this is confirmed, it may be used.

Moreover, it is thought that the same effect as each Example will be acquired if the electrical property described in the claim is satisfy | filled, such as adding electroconductivity imparting agents other than KI. For example, the film which added electroconductive carbon to polyethylene and / or ethylene vinyl acetate copolymer resin is mentioned. However, when carbon is added, the film becomes black and the transparency is lowered, so that the contents cannot be visually recognized and is not suitable for food distribution. Furthermore, there is currently no conductive carbon that meets safety standards and can be used for food contact applications.

DESCRIPTION OF SYMBOLS 1 ... Surface voltage measuring apparatus, 10 ... Freezer, 20 ... Insulating support part, 30 ... Tray, 40 ... DC power supply, 50 ... Voltmeter, 100 ... Storage bag, 200 ... Frozen object

The present invention relates to a method of producing container housing the refrigeration products. In particular, the present invention relates to a technique of freezing while applying an electric field or a magnetic field to an object to be frozen.

Therefore, it is desirable to freeze after vacuum packaging. However, when frozen from the vacuum packaging, in spite of the application of freezing, there is a case in which drip will come out at the time of thawing.
In view of the above-described problems, an object of the present invention is to provide a technique capable of suppressing the occurrence of drip at the time of thawing even when a product to be frozen is frozen in a state of being stored in a storage body.

This invention made | formed in order to achieve this objective is a method of producing the storage body which accommodated frozen goods, Comprising: The following 1st process and 2nd process are provided. In the first step, an unfrozen frozen object is stored as a storage object in a storage space as a space for storing the storage object, and a storage body in which the frozen object is deaerated and packaged in the storage space is electrically conductive. Placed on the mounting plate.

  As a storage body, the surface resistance of the inner surface which contacts the frozen object of the said storage body which forms the boundary of storage space is 1.3 * 10. ^Ten A container having a resistance of Ω / □ or less can be employed.
  And in a 2nd process, the frozen object accommodated in the storage body mounted in the mounting board is cooled in the state which applied the alternating voltage and the DC voltage to the mounting board simultaneously. In this invention, the storage body which accommodated the frozen goods formed by freezing the object to be frozen is produced through the first step and the second step. According to this invention, it is possible to prevent the occurrence of drip at the time of thawing by applying freezing.

  The container may be formed of a multilayer film having an inner surface constituting layer constituting the inner surface and a biaxially stretched polyamide layer different from the inner surface constituting layer. As the multilayer film, the first layer is composed of an inner surface constituting layer, the second layer following the first layer is composed of a linear low density polyethylene (LLDPE) layer or a branched low density polyethylene (LDPE) layer, A multilayer film in which the third layer following the layer is a biaxially stretched polyamide layer can be employed.

  In addition, the storage body can employ a configuration in which the inner surface constituting layer is made of a material in which a predetermined polymer substance and potassium ionomer are blended. As a material in which potassium ionomer is blended, for example, a material in which the blending ratio of potassium ionomer is 19% or more can be adopted.

  In the third aspect of the present invention, after the second step, the third object for freezing the object to be frozen stored in the storage body mounted on the mounting plate in a state where only the AC voltage or the DC voltage is applied to the mounting plate. A process can be provided. That is, it is possible to produce a storage body that stores a frozen product obtained by freezing an object to be frozen, through the first to third steps.

Claims (9)

A storage body having a storage space as a space for storing a storage object,
A storage body, wherein a surface resistance of an inner surface of the storage body forming a boundary of the storage space is set to 1.3 × 10 ¹⁰ Ω / □ or less. A storage body having a storage space as a space for storing a storage object,
At least the inner surface of the storage body forming the boundary of the storage space is made of a material in which a predetermined polymer substance and potassium ionomer are blended, and the blending ratio of potassium ionomer is 19% or more. A storage body characterized by.   The storage body according to claim 1 or 2, wherein a frozen product or an unfrozen frozen object is stored as the storage object. A first step of mounting the storage body according to claim 1 or 2 on which an unfrozen frozen target object is stored as the storage target object on a conductive mounting plate;
A second step of cooling the object to be frozen stored in the storage body mounted on the mounting plate in a state where the alternating voltage and the direct current voltage are simultaneously applied to the mounting plate;
After the second step, the third step of freezing the object to be frozen stored in the storage body placed on the mounting plate, with only the AC voltage or DC voltage applied to the mounting plate,
And producing a storage body containing a frozen product obtained by freezing the object to be frozen by the steps from the first to the third step. A first step of applying an alternating electric field and / or a magnetic field to the storage body according to claim 1 or 2, wherein an unfrozen frozen object is stored as the storage object,
A second step of freezing the object to be frozen stored in the storage body by applying cold air to the storage body on which the alternating electric field and / or magnetic field is applied;
With
The second step is capable of adjusting the wind direction and the amount of air to make the cold air rectified into a parallel flow, and further sucking and re-rectifying the rectified cold air and additionally blowing air at a uniform flow rate and flow rate. In the process of supplying cold air rectification,
In the first step, when an alternating electric field is applied, electric field energy having a frequency of 50 kHz to 5 MHz can be continuously scanned, or electric field energy having a frequency changed stepwise can be scanned. Applying a static magnetic field and / or a variable magnetic field by an electromagnetic coil disposed so as to surround, sandwich, or straddle a holder that holds the object to be frozen through the storage body And
According to the first and second steps, a storage body containing a frozen product obtained by freezing the object to be frozen is produced. The ambient temperature of the storage body is set to -100 ° C to -30 while a unidirectional magnetic field is applied to the storage body according to claim 1 or 2 which stores an unfrozen frozen object as the storage object. The first step of rapid freezing and cooling to
A second step of cooling the object to be frozen stored in the storage body by applying cold air of 1 to 5 m / sec to the storage body, and superimposing sound waves in an audible frequency band on the cold air;
With
The magnetic field in one direction fluctuates and fluctuates in a predetermined range in the positive and negative directions with a frequency of 50 or 60 Hz with respect to an arbitrary fixed value in the range of 1 to 20000 Gs. Yes,
A storage body production method for producing a storage body storing a frozen product obtained by freezing the object to be frozen by the first step and the second step using the magnetic field. The 1st process of holding the frozen object stored in the storage object with the holder via the storage object according to claim 1 or 2 which stored the unfrozen frozen object as the storage object. When,
A second step of freezing the object to be frozen stored in the storage body by applying an alternating electric field and a magnetic field to the storage body and applying cold air to the storage body;
With
The alternating electric field applied in the second step is an alternating electric field whose frequency is continuously changed in a frequency range of 50 Hz to 5 MHz,
The magnetic field applied in the second step surrounds the holder that holds the object to be frozen, spans the holder that holds the object to be frozen, sandwiches the holder that holds the object to be frozen, or surrounds the holder that holds the object to be frozen. And a static magnetic field and / or a variable magnetic field generated by a dielectric coil provided so as not to disturb the cold air,
A storage body production method for producing a storage body storing a frozen product obtained by freezing the object to be frozen by the first process and the second process using the alternating electric field and magnetic field. The 1st process of holding the frozen object stored in the storage object with the holder via the storage object according to claim 1 or 2 which stored the unfrozen frozen object as the storage object. When,
A second step of freezing the object to be frozen stored in the storage body while applying a static magnetic field and a variable magnetic field to the storage body;
With
The static magnetic field is 1 to 10000 Gs,
The fluctuating magnetic field is generated by a plurality of electromagnetic coil structures that generate a fluctuating magnetic field of 0.1 to 1000 Gs by energizing alternating current,
The electromagnetic coil structure spans a holder that holds the object to be frozen or surrounds the holder that holds the object to be frozen, and a plurality of the electromagnetic coil structures extend along the holder. Are arranged so that they are parallel, orthogonal, or crossed,
Producing a storage body containing a frozen product obtained by freezing the object to be frozen by the first step and the second step using the magnetic field generated by the static magnetic field and the electromagnetic coil structure. A method for producing a storage body. First, dielectric CAS aging treatment is performed in which an unfrozen object to be frozen is aged in an atmosphere having a temperature of 2 to 15 ° C. and a relative humidity of 98 to 100% under the action of a static magnetic field and a variable magnetic field or an alternating electric field. Process,
Flow velocity: a second step of immersing the hydrated object subjected to the dielectric CAS aging treatment in a dielectric CAS magnetic water obtained by applying a static magnetic field and a variable magnetic field or further an alternating electric field to flowing water of 2 m / s or more;
A third step of draining the frozen object treated in the second step;
A fourth step of performing a dielectric CAS drying process in which the object to be frozen processed in the third step is dried in a reduced pressure atmosphere at a temperature of 2 to 15 ° C. under the action of a static magnetic field and a variable magnetic field or an alternating electric field;
A fifth step of storing the frozen object subjected to the fourth step in the storage body according to claim 1 or 2,
A sixth step of cooling the object to be frozen stored in the storage body to a temperature of −60 ° C. to 0 ° C. while applying a static magnetic field and a variable magnetic field or further an alternating electric field to the storage body;
A seventh step of performing a dielectric CAS freezing process in which the frozen object stored in the container subjected to the sixth step is quickly frozen at the temperature cooled in the sixth step;
And a storage body containing a frozen product obtained by freezing the object to be frozen is produced through the steps from the first step to the seventh step.