JPH09272180A - Packaging material corresponding to heating in microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid possibility of breakage even when the whole container is treated in a microwave oven by providing an outer layer consisting of a heat- resistant thermoplastic resin film, an inner layer consisting of a sealant film and an intermediate layer consisting of a release agent layer. SOLUTION: A packaging material of a plastic container for a frozen food or a chilled food put in a container corresponding to heating in a microwave oven is a laminated plastic film wherein an outer layer consists of a heat- resistant thermoplastic resin film and an inner layer consists of a sealant film and a release agent layer is provided as an intermediate layer. When the microwave oven is heated, a through-fine hole for a vent for steam, etc., is generated along the release agent provided on the seal face from the sealant film layer positioned in the neighborhood of the seal face caused by inner pressure generated in a container contg. food.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to frozen foods and chilled foods, which are sealed in a plastic packaging material and heated in a microwave oven, and only when the temperature rises and the internal pressure is applied, the gas is penetrated to remove gas such as water vapor. Frozen and chilled food products in plastic containers with a release agent applied to the sealing surface to create pores, as well as automatic packaging with a release agent pattern applied to create such a food container. It relates to a material roll for machine plastic packaging.

[0002]

2. Description of the Related Art Conventionally, frozen foods such as shumai, croquettes, menchikatsu, rice balls, yakisoba, Chinese buns and chilled foods such as hampen, sweet potatoes, prepared foods, etc., are stored in plastic trays and are also hermetically sealed plastic packaging materials. Are stored in a container (outer bag) and kept in a sealed state after freezing or refrigeration.

Therefore, when such frozen food products and chilled food products are cooked and heated in a microwave oven, it is convenient if the entire outer bag can be microwaved.
There is a possibility of rupture, and the rupture may cause surprises and scattering of contents, which is not preferable. The contents must be taken out of the outer bag and microwaved to prevent rupture. However, this is not a preferred method for foods that have a good texture by steaming, such as shomai, meat bun, and bean jam bun. PL
It is necessary to design a container so that a consumer can perform a desired heating cooking regardless of a heating method.

As a method of preventing rupture when the outer bag is put in a microwave oven, for example, a through hole for degassing fine water vapor or the like penetrating inside and outside the outer bag is provided in a seal portion of the outer bag (container). It is possible to keep it in a bag, but foreign matter enters into the bag through this hole and is unsanitary.In addition, in the case of chilled food, it may not be able to withstand long-term storage due to decay due to microbial contamination. It is difficult to adopt such a means.

[0005]

Under the background of the prior art described in the preceding paragraph, an object of the present invention is to keep frozen food or chilled food in a plastic sealed container in the container, that is, to put the container in a microwave oven. It is intended to provide a frozen food product or a chilled food product in a container that does not have a risk of bursting even when heated.

[0006]

Means for Solving the Problems As a result of earnest research to achieve the object described in the preceding paragraph, the present inventor has found that in frozen frozen foods or chilled foods in plastic containers, gas such as steam cannot be produced until internal pressure is applied. In order to generate the through-holes for removal, a laminated plastic film in which the outer layer is made of a heat-resistant thermoplastic resin film, the inner layer is made of a sealant film, and the intermediate layer is provided with a release agent layer is used. The present invention was completed based on this finding, finding that it is suitable as a packaging material compatible with microwave heating. With this configuration, the laminate strength of the part provided with the release agent layer is weakened, and at the same time, the heat seal strength of the release agent layer part is weakened when the sealing surface is sealed by the seal bar, and as a result, when the microwave oven is heated, the food is heated. Due to the internal pressure generated in the container, through pores for venting gas such as water vapor are generated from the sealant film layer located near the seal surface along the release agent provided on the seal surface.

That is, according to the present invention, the internal pressure generated in the plastic container during heating in the microwave oven causes through holes for venting gas such as water vapor to be generated along the release agent applied to the sealing surface of the plastic container. Microwave oven-compatible plastic containers containing frozen foods or chilled foods, and packaging materials for making such container-containing products using an automatic packaging machine, that is, frozen foods or chilled foods with an automatic packaging machine. A roll material of a plastic packaging material for an automatic packaging machine for automatically packaging a plastic container for storing the food, wherein a gas such as steam is generated by the internal pressure generated in the container containing the food when heated in a microwave oven. The release agent is pattern-coated on one surface so that the through-holes for removal are formed along the release agent applied to the sealing surface of the plastic container. A laminated thermoplastic resin film packaging material which are.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

Products such as frozen foods and chilled foods in plastic containers are produced in the following manner using, for example, an automatic packaging machine. That is, molded foods (for example, shoe mai) to be packaged and subjected to a freezing or refrigeration treatment are stored in a tray, and the tray is sequentially moved in a certain direction on an automatic packaging line. At the same time, the winding of the plastic packaging material forming the plastic container (outer bag) is unwound so as to cover the upper part of the tray in the moving direction of the tray, and the left and right sides in the moving direction are wrapped around the tray and fitted. This is further moved on an automatic packaging line. First, the joined portion is passed between hot plates to perform back bonding (seal) by heat welding, and then the opening at the front end in the moving direction is sealed by a heat seal bar. To further seal the opening at the rear end in the movement direction (this is also the seal at the opening at the front end in the movement direction of the subsequent unit package),
Finally, the sealing material at the opening is cut transversely in the longitudinal direction of the packaging material to obtain an intermediate product of frozen food or chilled food in a container (outer bag) containing one tray at a time. This intermediate product is subjected to a freezing treatment or a chilled treatment and placed in a distribution as a frozen food or a chilled food product in a container (outer bag).

According to the present invention, the frozen food or chilled food in a plastic container thus produced,
When a container (outer bag) is heated in a microwave oven together with the container in order to eat the food later, a through-hole for venting gas such as water vapor is generated only when the temperature rises and the internal pressure is increased. Then, the release agent is applied in advance. The release agent can be appropriately applied to any of the seal surfaces described above, that is, the seal surfaces of the back-attached seal portion and the seal portions at the front and rear end openings.

The packaging material for a plastic container for frozen food or chilled food in a microwave heating container according to the present invention comprises an outer layer made of a heat-resistant thermoplastic resin film, an inner layer made of a sealant film, and an intermediate layer. Is a laminated plastic film provided with a release agent layer.

The heat-resistant thermoplastic resin film constituting the outer layer is not particularly limited as long as it has a melting point of 160 ° C. or higher and is generally used as a packaging material for packaging frozen foods and chilled foods. However, polyethylene terephthalate film, silica deposited polyethylene terephthalate film, alumina deposited polyethylene terephthalate film, biaxially oriented polypropylene film, biaxially oriented nylon film, etc. are preferably used in terms of heat resistance, strength physical properties, transparency, printability, and moisture resistance. can do. The thickness of the outer layer is about 9 to 50 μm, preferably about 12 to 30 μm.

Since the sealant film constituting the inner layer is disposed on the surface which comes into contact with food, it is naturally limited to a highly safe film, for example, general-purpose polyolefin film and special polyolefin film. You can Specifically, low density polyethylene (L
DPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), unstretched polypropylene (CP
P), linear low density polyethylene (L-LDPE), ultra low density polyethylene (VLDPE) ethylene / vinyl acetate copolymer (EVA), ethylene / acrylic acid copolymer (EAA), ethylene / methacrylic acid copolymer Coalescence (EMA
A), ethylene / ethyl acrylate copolymer (EE
A), ethylene / methyl methacrylate copolymer (EM
MA), ethylene-methyl acrylate copolymer (EM
A) and films such as ionomers (IO).

As shown in FIG. 4, the inner layer has a portion disposed near the seal surface coated with the release agent, when the frozen food or chilled food in a container is heated in a microwave oven for the first time by the internal pressure of steam or the like. It only needs to be strong enough to cut in the direction of the seal surface (causes cracks),
Further, the strength may be not larger than the strength of the thermoplastic resin film layer of the outer layer to be laminated. The thickness of the inner layer is not generally defined by the type of the sealant used, but is usually about 15 to 130 μm, preferably about 20 to 70 μm.

As the release agent, a polyamide / silicone release varnish "X218PE" (manufactured by Toyo Ink Co., Ltd.),
Acrylic / urethane-based “Shrink EX Medium” (manufactured by Toyo Ink Co., Ltd.) and “Rio Fresh” (manufactured by Toyo FCC Co., Ltd.) include calcium carbonate-containing shellac resin-based edible ink.

The release agent is used as a release agent by directly printing on a raw packaging material or by printing with a printing ink for content indication, imparting a sensation, etc., as described in the examples below, and then printing frozen food in a container or chilled food by electronic means. A pattern is formed on the entire surface of one side of the raw packaging material in such a pattern that through-pores for venting gas such as water vapor are generated only when heated in a microwave oven. Therefore, no matter where the sealed portion is in the original packaging material, the release agent can be located at both ends of the sealed portion.

[Rio Fresh] and peeling varnish "X"
218PE ”has a lamination strength of 1 to 30 g / 15
mm width and weak.

As a means for further increasing the effect of the release agent,
It is preferable to add 1 to 10% by weight, preferably 2 to 5% by weight of an inorganic substance such as calcium carbonate. Examples of the inorganic material include magnesium oxide, aluminum oxide, titanium oxide, magnesium carbonate, zinc carbonate, calcium sulfate, barium sulfate, sodium silicate, magnesium silicate, clay, diatomaceous earth, talc and kaolin.

When the release agent is applied to the thermoplastic resin film layer constituting the outer layer with or without the ink layer, the sealant film constituting the inner layer is subsequently laminated via the adhesive layer or by heat welding. By doing so, it is possible to obtain a packaging material that is compatible with microwave oven heating and that is made of a laminated plastic film. The lamination method is appropriately selected depending on the properties of the sealant resin, and a sealant film may be formed on the outer layer on the release agent application surface side by a so-called melt extrusion lamination method.

In producing the packaging material for microwave oven heating according to the present invention, regarding the seal strength, the relation between the seal strength of the portion to which the release agent is applied and the seal strength to which the release agent is not applied is that the seal strength is 1 for the non-application portion. As long as the seal strength of the part coated with the release agent is in the range of 0.3 to 0.7, the degassing function in the container can be sufficiently fulfilled.

In the production of a frozen food product or a chilled food product in a microwave-heatable container according to the present invention described above by an automatic packaging machine, a release material applied to a material roll of a plastic packaging material that constitutes the container. In short, the pattern may be such that such a product in a container is heated in a microwave oven as it is, the temperature rises and internal pressure is applied, and then through holes for venting gas such as water vapor are formed on the sealing surface. Therefore, there are no special restrictions.

Such patterns can be roughly classified into a linear type and other irregular types.

The straight type is, for example, as shown in FIG. 1, three straight lines (each having a width of 7
(mm, 15 mm, 25 mm) The release agent is applied in a thin strip pattern. For example, when applying in a strip pattern with a width of 20 mm, the seal width of the heat seal bar (the length of the rectangular seal portion in the longitudinal direction of the packaging material)
The same as or wider than is preferable. If it is narrow, it will be difficult to open unless it is opened at an obtuse angle rather than an angle of 45 °. The width of the release agent is 3 ~
It is 30 mm, preferably 6 to 20 mm. The thickness is 0.5 to 5 μm, preferably 1 to 3 μm. When the width of the release agent is less than 3 mm, when the microwave is applied, the water vapor concentrates there, so that the escape is worsened, and in the worst case, the vapor does not escape and bursts. On the other hand, if the width exceeds 30 mm, the sealing condition as a whole deteriorates, which may cause a problem of bag breakage due to insufficient seal strength during the distribution process.
With respect to the thickness of the release agent layer, if the thickness is less than 0.5 μm, the ink is impregnated with the gravure ink for printing, and the desired degassing effect is not obtained. Further, when it exceeds 5 μm, the coated part is swelled when the raw fabric is wound,
The film stretches and wrinkles, detracting from aesthetics.

The variant type is, for example, as shown in FIG. In this pattern, if the left and right patterns (a) and (b) are shifted by a half pitch, even if the position of the heat seal bar is displaced, at least one of the applied parts (a) and (b) has a seal width. Since the release agent is applied across, it is possible to save the number of alignment steps.
By appropriately changing the shape of the pattern, it is possible to make escape of gas such as water vapor at the time of heating difficult by providing a bent portion in the through pore in a pattern in which S-shapes are connected. Difficult pattern of escape of gas such as water vapor, when put in a microwave oven, rather than simply heating, it is desired to perform some steaming treatment,
Suitable for frozen foods such as Chinese buns.

Examples of the container to which the strip-shaped release agent and the atypical pattern release agent are applied are shown in FIGS. 5 and 6, respectively.
In both cases, the release agent is applied across the width of the sealing surface.

The pattern of the release agent applied to the raw material of the plastic packaging material that constitutes the container is, in short, the frozen food or the chilled food contained in the container when the container is microwaved together Although a through-hole for venting gas such as water vapor is generated on the sealing surface so as to heat up, the pattern of such a release agent for a given case, including its size, will be described later. Those skilled in the art can easily find out by performing a simple pre-test with reference to the examples.

Needless to say, coloring the release agent facilitates management.

Further, in the present invention, the gas in the case of degassing water vapor or the like includes, in addition to water vapor, air remaining in the container during the production of the food product in the container and volatile components generated from the food product in the container.

In the above description, the container is assumed to be a bag-shaped product for frozen foods or chilled foods, which is produced by an automatic packaging machine using a thermoplastic resin film as a packaging material. Therefore, the container is made of such a thermoplastic resin film.

However, for example, as shown in FIG. 3, frozen food or chilled food is contained in the main body of a heat-meltable molded product container, which is covered with a heat-meltable film and heat-sealed. In the case of packaged products that have been subjected to microwave oven heating as well, the possibility of bursting is the same as for packaged products with automatic packaging machines as described above, and Similarly, the fear can be avoided by applying a release agent and sealing so that through pores for venting gas such as water vapor are generated only when internal pressure is applied to the sealing surface. Therefore, the container of the present invention also includes such a molded product container.

Further, in the case of a container prepared by accommodating frozen food or chilled food in a so-called standing pouch and heat-sealing the opening, there is a similar problem, and the same problem can be solved. Needless to say, the container referred to as a product includes a container using a standing pouch.

The seal of the laminated plastic container for frozen foods or chilled foods according to the present invention, which can be heated in a microwave oven, will be briefly described below. The thermoplastic laminated resin film packaging material of the present invention is folded in order to pay the food, and the sealant film layer is laminated inside, and the laminated portion is heated and sealed by heat welding. In this case, this portion may be welded by applying heat for the purpose of strengthening the fold of the folded portion. Therefore, in the case of a finished rectangular container, the seal is a three-sided seal or a four-sided seal.
After pasting the above packaging material at the peripheral edge of the container body so that the sealant film layer is on the inside, a frozen food obtained by sealing the peripheral edge by heat welding or a chilled food microwave oven compatible plastic container An example is as shown in FIG.

The thickness of the sheet forming the container is 25
0 to 800 μm.

When manufacturing the container of claim 7, as shown in FIG. 7, a sealant film (B2) having a large tensile strength, which is used as an outer layer and an inner layer, and a sealant film in the packaging material according to claim 1, which is used as an inner layer. Layer (B
The thickness relationship with 1) is B2 = 1 when the same material is used.
On the other hand, if B1 is 0.7 or less, the function of degassing the container can be sufficiently achieved. When the materials are different, it is necessary to adjust it in advance so that the gas venting function of the present invention can be exhibited in consideration of tensile strength and the like.

[0035]

The present invention will be described below in detail with reference to examples. Of course, the present invention is not limited to this.

Example 1 In the production of packaging material for frozen foods, a polyethylene terephthalate film (PET film 16 μm thick, 940 m thick)
6-color printing with a gravure printing machine, and then with the same gravure printing machine as a release agent Toyo Ink Co., Ltd.
Using stripping varnish "X218PE", as shown in Fig. 1, strip-shaped patterns having widths of 7 mm, 15 mm and 25 mm, respectively, are applied at predetermined intervals in the longitudinal direction of the roll material by printing, and then applied on a dry laminating machine. , Urethane-based adhesive "ADCOAT AD-545S" (Toyo Morton
Co., Ltd.), milk white linear low density polyethylene film (milk white L-LDPE film, 40 μm thick, width 900 m)
m) was pasted together to prepare a roll material of a laminated plastic packaging material for an automatic wrapping machine compatible with microwave heating.

Example 2 In the production of packaging material for frozen foods, biaxially oriented polypropylene (OPP film 20 μm thickness, 900 mm width) was printed in 6 colors by a gravure printing machine, and then as a release agent, Toyo Ink Co., Ltd. ) Manufactured by using a peeling varnish "X218PE", the viscosity thereof is set to Zurcup No. 3 16 seconds, and the gravure plate is 75 lines / inch, and the plate depth is 30 μm. As shown in FIG. 1, widths are 7 mm, 15 mm and 25 mm, respectively. A pattern is printed and applied at a predetermined interval in the longitudinal direction of the material roll, and polypropylene resin "LS-712" (Japan Polyolefin Co., Ltd.) is used in a single extrusion laminating machine.
Melt-extruded film (20 μm thick, 940 mm)
Width) was pasted to form a roll material of a laminated plastic packaging material compatible with microwave heating.

Example 3 In the production of packaging material for frozen foods, PET film (16
(μm thickness, 940 mm width) 6 in a gravure printing machine
Color printing is performed, and then Toyo Ink Co., Ltd. is used as a release agent.
Using a stripping varnish “X218PE”, a strip-shaped pattern with a width of 7 mm shown in FIG. 1 is applied by printing in the longitudinal direction of the roll material, and then the urethane adhesive “Adcoat AD” is used in the first dry laminating machine of the tandem dry laminating machine. −
900 "(manufactured by Tokyo Morton Co., Ltd.), milky white L-LDP
The E film (40 μm thickness, 940 mm width) is laminated and the pattern of FIG. 2 is gravure-printed in the second dry laminating machine; 175 lines, depth 36 μ, as a release agent, a shrack system manufactured by Toyo FCC Co., Ltd. Edible ink: "Rio Fresh" Carbonated calcium chloride was printed to create a roll material of a laminated plastic packaging material for microwave heating.

Example 4 A roll having a 7 mm width of the release agent coating shown in FIG. 1 slitted into a width of 300 mm was prepared from the original roll prepared in Example 1, and a high speed fully automatic pillow packaging machine (S-5000J) was used. (Omori Machinery Co., Ltd.) seal temperature 230 ℃, line speed: 120 shots / minute, seal width 8.5m
In "m, 225 g containing 15 shrimps" was packed in a tray having a bag size of 135 x 240 mm. Thereafter, it was frozen at -30 ° C. The obtained frozen food "Ebi-shumai" pack was directly applied to Matsushita Electric Industrial Co., Ltd. microwave oven (model: NE-2) 600W for 4 minutes and 30 seconds, resulting in 3 minutes and 30 seconds. The whole pouch swells, and after 4 minutes and 15 seconds, water vapor escapes under pressure from the water vapor release structure of the pattern of FIG. 1 of the seal part,
After 4 minutes and 30 seconds, it was ready to eat.

Example 5 The roll material prepared in Example 2 was prepared by slitting a 15 mm-wide release agent-coated packaging material shown in FIG. 1 into a slit having a width of 300 mm to prepare a roll, and using an impulse sealing machine (Fuji Impulse Co., Ltd.). Made by:
FA-600-10) was used to put one commercial frozen food "Nikumanju" in a bag size of 150 x 150 mm with a dial 5 and a seal width of 10 mm. Then, it was left in a freezer at -20 ° C for one day. A pack of the obtained frozen food "Nikumanju" was applied to a microwave oven (model: NE-2) 600W manufactured by Matsushita Electric Industrial Co., Ltd. as it was for 1 minute 40 seconds at a high setting, and 1 minute 05 seconds later. The entire pouch swelled, and after 1 minute and 26 seconds, water vapor escaped under pressure from the water vapor vent structure of the seal portion having a pattern of weak sealing strength shown in FIG. 1 and became ready for eating 1 minute and 40 seconds later. As a result of measuring the seal strength, the portion not coated with the release agent had a width of about 700 g / 15 mm, while the portion coated with the release agent had a width of about 300 g / 15 mm.

Example 6 The release agent-coated packaging material of FIG. 1: 7 mm prepared in Example 3 was slit into a width of 300 mm to prepare a roll, and a high speed fully automatic pillow packaging machine (manufactured by Omori Machinery Co., Ltd.) was used. Use seal temperature 210 ℃, line speed: 120 shots / minute,
Packing was performed in a tray having a bag size of 135 × 240 mm with a seal width of 8.5 mm and “225 g of 15 shrimp chow mei”. Thereafter, it was frozen at -30 ° C. A pack of the obtained frozen food "Ebi-shumai" is directly used in a microwave oven manufactured by Matsushita Electric Industrial Co., Ltd. (model: NE-2) 600.
As a result of applying a strong setting at W for 4 minutes and 30 seconds, the whole pouch swelled after 3 minutes and 30 seconds, and after 4 minutes and 05 seconds, water vapor was generated while pressure was applied from the water vapor vent structure of the seal portion shown in FIG. It came off and became ready to eat 4 minutes and 30 seconds later.

Incidentally, in the sixth embodiment, the seal temperature is 21.
Packaging was performed under exactly the same conditions except that 0 ° C was changed to 180 ° C. Thereafter, it was frozen at -30 ° C. The frozen food "Ebi-shumai" pack obtained is directly used by Matsushita Electric Industrial Co., Ltd.
As a result of applying a strong setting with a microwave oven (model: NE-2) made of 600W for 5 minutes and 00 seconds, the whole pouch swelled after 3 minutes and 30 seconds and bursted from the back seal portion after 4 minutes and 20 seconds and failed. The sealing temperature is a normal suitable temperature (200 to 24
If the temperature is lower than 0 ° C), water vapor will not escape from other portions where the seal strength is weak.

Example 7 7 mm width in FIG. 1 prepared in Example 3 and 6.5 m in FIG.
The width of 300m for the packaging material obtained by the m-width release agent coating pattern
Prepare a roll slit in m and use a high-speed fully automatic pillow packaging machine (Omori Machinery Co., Ltd.) to seal at a temperature of 26
At 0 ° C., line speed: 120 shots / minute, and a seal width of 8.5 mm, the "shumai" tray was packaged. Thereafter, it was frozen at -30 ° C. The obtained frozen food "Shumai" pack is used as it is, Matsushita Electric Industrial Co., Ltd.
As a result of applying a strong setting with a microwave oven (model: NE-2) 600W for 4 minutes and 30 seconds, the whole pouch swelled after 3 minutes and 30 seconds, and 9 out of 10 bags, around 3 minutes and 50 seconds. Water vapor escapes from the water vapor removal structure of the seal part, and the remaining one bag is a quarter of the width 7 mm in Fig. 1 where the seal strength is weak.
After 0 seconds, water vapor was released, and after 4 minutes and 30 seconds, the food was ready to eat. When the seal temperature was set high, the effect of releasing water vapor from the seal portion in FIG. 1 was observed.

Example 8 Packaging material for retort standing pouch; PET 12 μm
In the production of 6-color printing / AD (adhesive) / PET 12 μm Siox vapor deposition (silica vapor deposition PET) / AD / ONy 15 μm release agent (Fig. 1, width 7 mm) / CPP 60 μm (unstretched polypropylene) for retort, first gravure printing machine With a biaxially stretched nylon film (ONy film 15 μm thick), a stripper with a width of 15 mm (“Rio Fresh” calcium carbonate 3 manufactured by Toyo FCC Co., Ltd.)
"MOS-TR" of SiOx vapor deposition for retort of Oike Industry Co., Ltd.
(Silica vapor deposition PET) is prepared and PE is made by gravure printing.
6-color printing on T film 12 μm, and urethane adhesive “ADCOAT AD-8” by dry laminating machine
11 "(manufactured by Toyo Morton Co., Ltd.), the above-mentioned components are pasted together, and a bag making machine" S
BM-600-TA type "(manufactured by Seibu Machine Co., Ltd.) was used to obtain a retort standing pouch having a width of 120 mm, a height of 160 mm, and a bottom height of 34 mm.

As a result of measuring the seal strength of each part with a Tensilon type tensile tester, 5 to 6 were found in places other than the release agent application.
The width was in the range of Kg / 15 mm width, and the stripping agent application part around the width of 7 mm was a weak state of about 3 Kg / 15 mm width.

The standing pouch thus obtained was charged with the raw material of porridge and sterilized by retort at 125 ° C. for 30 minutes and left in the room for one day. Okayu Standing Pouch,
Microwave oven (model: RO-7700) manufactured by Mitsubishi Electric Corporation 9
Strong setting at 90W, 4 minutes 30 seconds, 3 minutes 40 minutes
After 2 seconds, the entire pouch swelled, and after 4 minutes, the steam was released from the water vapor release structure of the seal portion under pressure, and after 4 minutes and 15 seconds, the pouch was ready for eating.

Example 10 Lid for retort container PET 6-color printing / AD / PETSi
ox deposition product / AD / ONy release agent (Fig. 1, width 15mm)
/ When laminating a CPP (unstretched polypropylene) structure for retort, first a biaxially stretched nylon film (ONy film 15 μm thick) with a width of 15 mm in a gravure printing machine.
Release agent (Toyo FCC "Rio Fresh" 3% calcium carbonate slack resin edible ink) is printed, and Oike Kogyo Co., Ltd.'s SiOx vapor deposition "M"
"OS-TR" is prepared, 6 colors are printed on the PET film by gravure printing, and the urethane adhesive "Adcoat AD-900" (manufactured by Toyo Morton Co., Ltd.) is used by a dry laminating machine. I made a lid for the component.
The container is CPP 80 μm / PVDC (polyvinylidene chloride) “Saran UB” from the inside (Asahi Kasei Co., Ltd.)
A 250 ml container shown in FIG. 3 was made by the plug-assisted pressure forming method using a sheet processed to have a structure of 15 μm / CPP 30 μm / PP (polypropylene) resin 400 μm. Pour rice, water and air into the obtained container, seal the above lid material with a prototype sealing machine under the condition of 230 ° C / 1 second / cm ² , and carry out retort sterilization treatment at 118 ° C for 30 minutes to prepare white rice. made.

After standing at room temperature for 24 hours, Matsushita Electric Industrial Co., Ltd.
Manufactured by microwave oven (model: NE-2) at 600W for 4 minutes 00 seconds with strong setting, the pouch swells after 3 minutes, and after 3 minutes 30 seconds, steam from the part coated with the 15 mm wide stripping agent After 3 minutes and 45 seconds, he was ready to eat.

Example 11 Lid material for a general container ONy 15 μm / 6-color printing / release agent (FIG. 1, width 15 mm) / CPP 30 μm for general bonding, first ONy (biaxially stretched nylon) with a gravure printing machine. 6-color printing on a film of 15 μm with a gravure printing machine, and a stripping agent with a width of 15 mm (Toyo Ink Co.
Release varnish "X218PE") is printed and the urethane adhesive "Adcoat AD" is applied by a dry laminating machine.
-900 "(manufactured by Toyo Morton Co., Ltd.) was used to make a lid material for the above-mentioned components.

The container is made of PP sheet and has a thickness of 0.27 mm, and is formed by a pressure molding method with a width of 150 mm and a length of 230 mm.
A tray with a depth of 45 mm was made. 320 g of fried rice was put into the obtained container, and the lid material was placed at 240 ° C./1 second / c.
Seal with a prototype sealing machine under the condition of m ² and -3
Frozen food was prepared by quenching to 0 ° C.

After being left at room temperature for 24 hours, a microwave oven (model: NE-2) manufactured by Matsushita Electric Industrial Co., Ltd. (model: NE-2) was set to 600 W for 4 minutes and 00 seconds with a high setting, and as a result, the whole tray swelled after 3 minutes and 35 minutes. After a few seconds, water vapor escaped from the part coated with the release agent having a width of 15 mm, and after about 3 minutes and 55 seconds, it was ready for eating.

[0052]

According to the present invention, a frozen food or a chilled food in a container is maintained in a sealed state during distribution, and when the whole container is placed in a microwave oven to eat the food, the gas is appropriately vented. Moderate pressure resistance is maintained,
Therefore, it is possible to appropriately heat the food according to the food, that is, to easily prepare a food having an appropriate moisture adjustment function and cooking and heating function.

[Brief description of drawings]

FIG. 1 shows an example of a coating pattern of a release agent (Examples 1, 2, 3).

FIG. 2 shows an example of a release agent coating pattern (Example 3).

FIG. 3 shows an example of a release agent coating pattern and a frozen food or chilled microwaveable container (Example 9).

FIG. 4 is a conceptual diagram showing a state in which water vapor escapes from the inner layer of the container.

FIG. 5 shows an example of a microwave oven-compatible container according to the present invention.

FIG. 6 shows an example of a microwave oven-compatible container according to the present invention.

FIG. 7 shows an example of a microwave oven-compatible container according to the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location B65D 81/34 B65D 81/34 V (72) Inventor Takeshi Fukumoto 6 Minatomachi, Kawasaki-ku, Kanagawa Prefecture No. 1 in Ace Package Co., Ltd. (72) Inventor Shoji Igata 6-1 Minatomachi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Ace Package Co., Ltd.

Claims (7)

[Claims] 1. A packaging material for microwave oven heating, wherein an outer layer is made of a heat-resistant thermoplastic resin film, an inner layer is made of a sealant film, and a laminated plastic film having an intermediate layer provided with a release agent layer. 2. The thermoplastic resin film constituting the outer layer is a polyethylene terephthalate film, a silica vapor deposited polyethylene terephthalate film, an alumina vapor deposited polyethylene terephthalate film, a biaxially oriented polypropylene film or a biaxially oriented nylon film. Packaging material for microwave heating. 3. The stripping agent layer in the intermediate layer is a strip or pattern having a width of 3 to 30 mm and a thickness of 0.5 to 5 μm in the longitudinal direction of the stripping agent on the inner surface of the outer layer with or without an ink layer. The packaging material for microwave oven heating according to claim 1, wherein the packaging material is provided in the shape of a sheet. 4. The sealant film constituting the inner layer is disposed on the surface that comes into contact with food, and is a low density polyethylene film, a medium density polyethylene film, a high density polyethylene film, a linear low density polyethylene film, an ultra low density polyethylene film, Unstretched polypropylene film, ethylene / acrylic acid copolymer film, ethylene / methacrylic acid copolymer film, ethylene / methyl acrylate copolymer film, ethylene / ethyl acrylate copolymer film, ethylene / methyl methacrylate copolymer film or The packaging material for microwave oven heating according to claim 1, which is an ionomer film. 5. The packaging material for microwave oven heating according to claim 1, wherein the sealant film forming the inner layer is laminated on the outer layer surface provided with the release agent layer via an adhesive or by heat welding. 6. The packaging material according to claim 1 is folded to contain a food, and the packaging material is laminated so that the sealant film layer is inside, or is laminated with the peripheral edge of the container body so that the sealant film layer is inside. A microwave-heatable plastic container containing frozen food or chilled food, which is obtained by sealing the periphery by heat welding. 7. A sealant film layer having a tensile strength higher than that of the sealant film layer is attached to the sealant film layer of the packaging material according to claim 1 to store food, and the peripheral edge is sealed by heat welding. Microwave oven compatible plastic container containing frozen food or chilled food.