JP7110587B2 - Packaging bags for microwave heating and packaged foods - Google Patents

Description

TECHNICAL FIELD The present invention relates to a microwave oven heating packaging bag and a packaged food, and more particularly, a microwave oven heating packaging bag made of a heat-sealed laminated film, and an electronic packaging bag in which food is sealed and packaged in the packaging bag. It relates to packaged foods for microwave heating.

A laminated film consisting of three layers, a base layer made of a polyethylene terephthalate film, an intermediate layer made of a polyamide film, and a sealant layer made of a polyolefin film, is generally used for packaging bags for microwave heating. It is The packaging bag made of this laminated film has excellent resistance to piercing received from the corners of other packaging bags during transportation, impact transmitted to the packaging bag, and bending due to the impact by including the polyamide film. It is possible to obtain

Packaging bags containing polyamide-based films are excellent in puncture resistance, impact resistance, and bending resistance as described above, but are inferior in heat resistance. For this reason, if food that becomes hot when heated in a microwave oven (for example, food containing a lot of oil or sugar, such as curry or pasta sauce) is stored in the packaging bag, the packaging bag may be punctured or deformed. may occur. For example, if food, especially solid matter, adheres to the inner surface of a packaging bag and is heated in a microwave oven, the microwaves will concentrate on the adhered food, and the heated food will melt the polyamide film in that area. It may pierce the packaging bag. Therefore, in order to improve the heat resistance of packaging bags, Patent Document 1 proposes a laminated film in which a polyethylene terephthalate (PET) film is used as an intermediate layer instead of a polyamide film.

JP 2008-308183 A

Since the packaging bag described in Patent Document 1 does not contain a polyamide film, it has excellent heat resistance. However, no consideration is given to the influence of the ink used for printing the packaging bag and the adhesive used for laminating the film on the food in the packaging bag.

For example, the substrate layer is made of a silica-deposited PET film (the silica-deposited layer functions as a barrier layer that prevents permeation of vapor, oxygen, etc.), the intermediate layer is made of a PET film, and the sealant layer is made of unstretched polypropylene (CPP ) In a laminated film composed of a film, a case is assumed in which ink is placed on a silica deposited layer to form a printed layer, and an adhesive for dry lamination is applied to both sides of an intermediate layer to form an adhesive layer. In that case, if organic solvents (ethyl acetate, toluene, etc.) remain in the printed layer or adhesive layer, the residual organic solvent may be eluted from the packaging bag by retort heating or microwave heating of the packaged food. The residual organic solvent eluted from the packaging bag may impair the taste and smell of the food and reduce the functionality of the food.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a packaging bag for heating in a microwave oven and a packaged food, which are excellent in functionality and heat resistance.

In order to achieve the above object, a packaging bag for heating in a microwave oven of the first invention is a microwave oven made by heat-sealing a laminated film so that a storage space for storing contents is formed inside the packaging bag. A heating packaging bag,
Equipped with a steam release mechanism for releasing steam in the accommodation space during microwave heating,
The laminated film comprises, from the outside of the packaging bag to the inside of the packaging bag, a substrate layer made of a polyester film, a printed layer, an intermediate layer made of a polyester film having a barrier layer, and a sealant made of a heat-adhesive polypropylene film. It is characterized by having a laminated structure including a layer.

A packaging bag for microwave heating according to a second invention is characterized in that, in the first invention, the barrier layer is positioned outside the packaging bag in the intermediate layer.

A packaging bag for microwave heating according to a third invention is characterized in that, in the first invention, the barrier layer is positioned inside the packaging bag in the intermediate layer.

A packaging bag for microwave heating according to a fourth invention is the polypropylene film according to any one of the first to third inventions, wherein the polypropylene film has an elongation at break of an average value of 900% or more or a Young's modulus of an average value of 600 MPa or less. characterized by having

A packaging bag for microwave heating according to a fifth invention is characterized in that, in the fourth invention, the thickness of the polypropylene film is 40 μm or more and 80 μm or less.

A packaging bag for microwave heating according to a sixth aspect of the invention is characterized in that, in any one of the first to fifth aspects of the invention, the content is 400 g or less.

The packaged food for microwave heating of the seventh invention is sealed and packaged in the packaging bag according to any one of the first to sixth inventions, with the food as the content contained in the accommodation space. It is characterized by

According to the present invention, since the intermediate layer has a barrier layer, even if the organic solvent remains in the printed layer or the like located outside the intermediate layer, the content can be removed from the packaging bag by heating with a microwave oven or the like. The barrier layer prevents the residual organic solvent from eluting into the food, so that the taste and smell of the food are not spoiled. In addition, since the base material layer and the intermediate layer are made of a polyester film, even if the packaging bag contains food that becomes hot when heated in a microwave oven, it is possible to prevent the packaging bag from being perforated or deformed. . Therefore, it is possible to realize a packaging bag for heating in a microwave oven and a packaged food having excellent functionality and heat resistance.

BRIEF DESCRIPTION OF THE DRAWINGS The external view which shows 1st Embodiment of the packaging bag for a microwave oven heating, and a packaged food. The external view which shows 2nd Embodiment of the packaging bag for a microwave oven heating, and a packaged food. The external view which shows 3rd Embodiment of the packaging bag for a microwave oven heating, and a packaged food. The external view which shows 4th Embodiment of the packaging bag for a microwave oven heating, and a packaged food. The external view which shows 5th Embodiment of the packaging bag for a microwave oven heating, and a packaged food. The external view which shows 6th Embodiment of the packaging bag for a microwave oven heating, and a packaged food. FIG. 7 is a cross-sectional view showing the layer structure of a laminated film that constitutes the packaging bag of FIGS. 1 to 6;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, packaging bags, packaged foods, etc. according to embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the same parts or corresponding parts among the respective embodiments, etc., and overlapping explanations will be omitted as appropriate.

1 to 6 schematically show external structures of packaging bags 101 to 106 and packaged foods 201 to 206 according to the first to sixth embodiments. 1 to 6, (A) is a plan view showing the stand-type packaging bags 101 to 106 in a folded state, and (B) is a packaged food in which the food F is sealed in the packaging bags 101 to 106. 2 is a front view showing 201-206; FIG.

The packaging bags 101 to 106 are composed of three sheets, a front sheet 1A, a back sheet 1B and a bottom sheet 1C, all of which are made of laminated films. Then, the laminated film is heat-sealed (thermally bonded) to form a bag so that a storage space 2 for storing the food F as a content is formed inside the packaging bag. A specific configuration of the laminated film (FIG. 7) will be described later.

The front sheet 1A and the back sheet 1B are heat-sealed at their right and left peripheries in a superimposed state, and the bottom sheet 1C folded in half is heat-sealed at their peripheries at the lower ends of the front sheet 1A and the back sheet 1B. ing. However, the upper edges of the front sheet 1A and the back sheet 1B are not sealed. That is, in the packaging bags 101 to 106, the body seal portion 4 is formed by heat sealing the front sheet 1A and the back sheet 1B, and the front sheet 1A, the back sheet 1B and the bottom sheet 1C are heat sealed. A housing space 2 is formed by the bottom seal portion 5 , and an opening 6 h is formed above the housing space 2 . In addition, V-shaped notches 4n are formed on the left and right peripheral edges above the trunk seal portion 4 to serve as starting points for unsealing. The shape of this notch 4n is not limited to the V-shape, and may be a linear shape, a U-shape, or the like.

The storage space 2 is filled with the food F from the opening 6h, and the front sheet 1A and the back sheet 1B are heat-sealed at the upper ends to form the top seal portion 6, as shown in (B) of FIGS. After forming and, if necessary, processing such as retort heating is performed, packaged foods 201 to 206 for heating in a microwave oven, in which the food F is contained in the containing space 2 and sealed and packaged, are obtained. When eating the food F, the packaged foods 201 to 206 are set in a microwave oven in a stand state and heated. Then, when the heating in the microwave oven is finished, the packaged foods 201 to 206 are opened by breaking the upper portions of the packaging bags 101 to 106 from the notch 4n, and the food F in the accommodation space 2 is transferred to the tableware. .

The packaging bags 101 to 106 are provided with a steam release mechanism 3 for releasing the steam V in the accommodation space 2 during microwave heating, and have the same configuration except for the steam release mechanism 3 and related parts. The vapor venting mechanism 3 is positioned on the upper side of the packaging bags 101 to 106 and has a function of forming a vaporizing section that communicates with the housing space 2 by microwave heating. For example, in the steam release mechanism 3 of the packaging bags 101 to 103, the protruding seal portion 3a connected to the body seal portion 4 is provided so as to protrude inside the packaging bag to form the planned steaming region 3H. When the packaging bags 101 to 103 are heated in a microwave oven and inflated by the steam V, the projected seal portion 3a gradually retreats (peels off) from the inner side of the planned steaming region 3H. This is an area that serves as a discharge path for steam V in a state where the inside and outside of 103 are connected. In addition, in the steam release mechanism 3 of the packaging bags 104 to 106, the ventilation chamber 4c that does not store the contents (food F), the point seal portion 3b that surrounds the ventilation chamber 4c and isolates it from the storage space 2, and the point seal A hole portion 3h or a notch portion 3s formed in the front sheet 1A and the back sheet 1B inside the portion 3b is provided.

In the steam release mechanism 3 of the packaging bag 101, the front sheet 1A and the back sheet 1B are heat-sealed on opposite sides so that the protruding seal portion 3a is connected to the body seal portion 4 to form a U-shape. . In the steam release mechanism 3 of the packaging bag 102, the front sheet 1A and the back sheet 1B are heat-sealed on opposite sides so that the protruding seal portion 3a is connected to the body seal portion 4 to form a trapezoidal shape. In the steam release mechanism 3 of the packaging bag 103, the front sheet 1A and the back sheet 1B are heat-sealed on opposite sides so that the protruding seal portion 3a is connected to the body seal portion 4 to form a V-shape. In the packaging bags 101 to 103, the protruding seal portion 3a and the body seal portion 4 are heat-sealed at the same time, and the width of the protruding seal portion 3a is narrower than the width of the body seal portion 4. As shown in FIG.

In the steam release mechanism 3 of the packaging bags 101 to 103, the above-described intended steaming region 3H is formed outside the packaging bag by the protruding sealing portion 3a provided so as to protrude inside the packaging bag in the front sheet 1A and the back sheet 1B. It is Among them, in the steam venting mechanism 3 of the packaging bags 101 and 102, the planned steaming region 3H is formed by the unsealed portion 4a provided outside the packaging bag of the protruding seal portion 3a, and the steam venting of the packaging bag 103 is formed. In the mechanism 3, the front sheet 1A and the back sheet 1B are scooped out in a V-shape outside the packaging bag of the projecting seal portion 3a to form a planned steaming area 3H. That is, the packaging bags 101 to 103 are configured to open from the trunk seal portion 4 toward the side of the packaging bag in the planned steaming region 3H. As in the V-shaped vaporization planned region 3H of the packaging bag 103, the unsealed portions 4a of the packaging bags 101 and 102 are hollowed out in the front sheet 1A and the back sheet 1B, thereby reducing the thickness of the packaging bags 101 and 102. The planned vaporization region 3H may be shaped like a letter or a trapezoid.

In the packaging bag 101, the unsealed portion 4b is formed at the same height position as the unsealed portion 4a in the body seal portion 4 on the side where the steam release mechanism 3 is not provided. As a result, in the manufacturing process of the packaging bag 101, when cutting along the body seal portion 4 at the side end extending in the vertical direction (TD direction) between the packaging bags 101 adjacent in the MD direction, the cutting position is determined by the processing accuracy. Even in the case of deviation, the planned vaporization region 3H can be reliably formed. In addition, the unsealed portion 4b may not be formed in the packaging bag 101 (for example, similar to the packaging bag 102), and the unsealed portion 4b may be formed in the packaging bag 102 (for example, the packaging bag 101). as well).

When the packaged foods 201 to 203 are heated in the microwave oven and steam V is generated from the foods F, the internal pressure of the containing space 2 increases. Since the protruding seal portion 3a of the steam release mechanism 3 protrudes into the pouch (inside the packaging bag), the protruding seal portion 3a is peeled off before the body seal portion 4 due to the internal pressure of the housing space 2. As a result, in the steam release mechanism 3 of the packaging bags 101, 102, the storage space 2 communicates with the unsealed portion 4a, and high-pressure steam V flows from the storage space 2 into the planned steaming region 3H. is exhausted to the outside of the Further, in the steam release mechanism 3 of the packaging bag 103 , the steam V in the accommodation space 2 is directly exhausted to the intended steaming area 3H located outside the packaging bag 103 . Since the steam venting mechanism 3 is arranged above the storage space 2, the food F is prevented from leaking from the planned steaming area 3H when the steam V is exhausted from the planned steaming area 3H.

In the steam release mechanism 3 of the packaging bags 101 to 103, as described above, the projecting seal portion 3a narrower than the body seal portion 4 is provided so as to form the planned steaming area 3H leading to the outside. It is possible to easily realize the steam release mechanism 3 that discharges the steam V by causing the housing space 2 to communicate with the outside of the packaging bag by increasing the internal pressure due to heating.

In the vapor release mechanism 3 of the packaging bags 104, 105, the front sheet 1A and the back sheet 1B are heat-sealed on opposite sides so that the point seal portion 3b is connected to the body seal portion 4 to form a P shape. there is In the steam release mechanism 3 of the packaging bag 106, the front sheet 1A and the back sheet 1B are heat-sealed on opposite sides so that the point seal portion 3b is separated from the body seal portion 4 to form a square shape. In the packaging bags 104 to 106, the point seal portions 3b and the body seal portions 4 are heat-sealed at the same time, and the width of the point seal portions 3b is narrower than the width of the body seal portion 4. As shown in FIG.

In the steam release mechanism 3 of the packaging bags 104 and 106, the hole 3h is provided in the front sheet 1A and the back sheet 1B inside the point seal portion 3b. A notch 3s is provided in the front sheet 1A and the back sheet 1B inside the sheet 3b. That is, the hole portion 3h and the notch portion 3s are formed to penetrate the packaging bags 104 to 106 at least in the ventilation chamber 4c configured to be surrounded by the point seal portion 3b.

When the packaged foods 204 to 206 are heated in the microwave oven and steam V is generated from the foods F, the internal pressure of the housing space 2 increases. Since the point seal portion 3b of the steam release mechanism 3 protrudes into the pouch (inside the packaging bag), the point seal portion 3b is peeled off before the body seal portion 4 due to the internal pressure of the storage space 2. As a result, the housing space 2 communicates with the ventilation chamber 4c, and the high-pressure steam V flows from the housing space 2 into the ventilation chamber 4c. The high-pressure steam V that has flowed into the ventilation chamber 4c is exhausted to the outside of the packaging bags 104-106 through the hole 3h or the notch 3s. Since the steam venting mechanism 3 is arranged above the housing space 2, the food F is prevented from leaking from the hole 3h when the steam V is exhausted from the hole 3h.

In the vapor release mechanism 3 of the packaging bags 104 to 106, as described above, the point seal portion 3b narrower than the body seal portion 4 is provided, and in the ventilation chamber 4c surrounded by the point seal portion 3b, Since the front sheet 1A and the back sheet 1B are provided with holes 3h or notches 3s, the internal pressure rise due to heating allows the storage space 2 to communicate with the outside of the packaging bag, thereby facilitating the steam venting mechanism 3 for exhausting the steam V. can be realized.

FIG. 7 shows laminated films 1a and 1b as specific examples of the three sheets 1A to 1C constituting the packaging bags 101 to 106 (FIGS. 1 to 6) in laminated cross section. The laminated film 1a shown in FIG. 7(A) and the laminated film 1b shown in FIG. 7(B) have the same configuration except that the arrangement of the barrier layer 14a and the resin layer 14b that constitute the intermediate layer 14 is different. ing. That is, the laminated film 1a includes, in order from the outside of the packaging bag to the inside of the packaging bag, the substrate layer 11, the printed layer 12, the adhesive layer 13, the intermediate layer 14 composed of the barrier layer 14a and the resin layer 14b, and the adhesive layer 13. and a sealant layer 15, and the laminated film 1b includes a base layer 11, a printed layer 12, an adhesive layer 13, and a resin layer in order from the outside of the packaging bag to the inside of the packaging bag. It has a laminated structure including an intermediate layer 14 composed of 14 b and a barrier layer 14 a, an adhesive layer 13 and a sealant layer 15 .

The base material layer 11 is made of a polyester film, and specific examples thereof include polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, and the like. The thickness of the substrate layer 11 is preferably 9-20 μm, more preferably 12-15 μm. If the thickness of the base material layer 11 is 9 μm or more, better dimensional stability and heat resistance can be obtained, and if it is 20 μm or less, better bending resistance can be obtained. Further, even if the base material layer 11 is not made of a special film (co-extruded film, etc.), it can be made to have a single-layer structure made of only a polyester-based film, thereby making it possible to reduce costs.

The printing layer 12 is a printing method using an ink composition (gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexo printing, etc.), and a desired printing pattern (characters, figures, etc.) is formed on the back surface of the base material layer 11. , symbols, patterns, etc.) is formed to a desired thickness (for example, 1 to 5 μm). The ink composition is mainly composed of one or more of ordinary ink vehicles. Add one or more additives (plasticizer, stabilizer, antioxidant, light stabilizer, UV absorber, curing agent, cross-linking agent, lubricant, antistatic agent, filler, etc.) as necessary Further, coloring agents such as dyes and pigments are added, and the mixture is sufficiently kneaded using a solvent, a diluent, and the like.

The adhesive layer 13 is formed of, for example, an adhesive commonly used in dry lamination. Specific examples of adhesives include polyvinyl acetate adhesives, polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, and polyamide adhesives. , amino resin-based adhesives, epoxy-based adhesives, polyurethane-based adhesives, and the like. The thickness of the adhesive layer 13 is preferably 0.5-5 μm, more preferably 0.5-2.5 μm. When the thickness of the adhesive layer is 0.5 μm or more, it becomes easy to control the film thickness, and when it is 5 μm or less, it becomes easy to suppress the production cost while imparting sufficient adhesive strength.

The intermediate layer 14 is composed of a barrier layer 14a for preventing permeation of steam, oxygen, etc., and a resin layer 14b made of a polyester film. The packaging bags 101 to 106 are pouches suitable for filling food F as contents. For this reason, the barrier layer 14a has a water vapor barrier property to prevent permeation of water vapor and oxygen gas, etc., so that the food F can be preserved while preventing deterioration due to oxidation of the food F (e.g., effect of extending the expiration date). It has a barrier property to prevent permeation of gas. The barrier layer 14a is not particularly limited as long as it is a layer that satisfies the above functions. By forming the barrier layer 14a with a vapor deposition film, it is possible to impart excellent water vapor barrier properties and oxygen barrier properties to the laminated films 1a and 1b.

As a method for vapor-depositing an inorganic substance on the resin layer 14b, there is a vacuum vapor deposition method (PVD method) in which an inorganic substance evaporated under reduced pressure is vapor-deposited on the resin layer 14b. A plasma-enhanced chemical vapor deposition method (CVD method) for vapor-depositing an inorganic material on the resin layer 14b may be used. As the inorganic substance to be deposited, for example, metal oxides such as silicon oxide (silica), aluminum oxide (alumina), and magnesium oxide can be used. For example, as a transparent barrier material for the transparent barrier PET film, silica (chemical vapor deposition: CVD), alumina (physical vapor deposition: PVD), PVA (polyvinyl alcohol)-based barrier resin coating agents, etc. can be used.

The sealant layer 15 is made of a heat-adhesive polypropylene film, and is provided for sealing by laminating the two laminate films 1a and 1b on top of each other and heat-sealing the opposing peripheral edges. Therefore, when the bag is made, it will be located on the innermost side of the packaging bag.

A specific example of the sealant layer 15 is a CPP layer made of unstretched polypropylene (CPP) film. Since the CPP film has excellent heat resistance, when foods that become hot when heated in a microwave oven (for example, foods containing a lot of oil and sugar such as curry and pasta sauce) are stored in the packaging bags 101 to 106 You can deal with it though. Also, the thickness of the sealant layer 15 is preferably 40 to 80 μm. The sealant layer 15 whose thickness is set within this range has excellent impact resistance against drops that may occur during the distribution process of the packaged foods 201 to 206, and facilitates filling and refilling of the contents. It is also easy to handle. When the thickness of the sealant layer 15 is 40 μm or less, the possibility of rupture tends to increase, and when the thickness of the sealant layer 15 is 80 μm or more, the cost tends to increase.

Laminated films 1a and 1b (FIG. 7) are made of a polyester film having a base layer 11 made of a polyester film, a printed layer 12, and a barrier layer 14a from the outside of the packaging bag to the inside of the packaging bag, as described above. and a sealant layer 15 made of a heat-adhesive polypropylene film. None of the layers contain a polyamide-based film, and the printed layer 12 and the adhesive layer 13 adjacent thereto are arranged outside the packaging bag relative to the barrier layer 14a.

Since the intermediate layer 14 has the barrier layer 14a, even if the organic solvent of the ink or the adhesive remains in the printing layer 12 or the adhesive layer 13 located outside the packaging bag from the intermediate layer 14, heat sterilization ( The barrier layer 14a prevents residual organic solvents from eluting from the packaging bags 101 to 106 to the food F due to retort heating), heat cooking (microwave heating), long-term storage, etc., so that the taste and smell of the food F are not spoiled. can be made In other words, the barrier layer 14a can prevent the taste and smell of the food F from deteriorating due to the elution of the residual organic solvent while maintaining the original function of the barrier layer 14a to prevent deterioration of the food F due to oxidation or the like. becomes. In addition, since the packaging bags 101 to 106 do not contain a polyamide-based film, and the base layer 11 and the intermediate layer 14 are made of a polyester-based film, the food F heated to a high temperature by microwave heating is accommodated in the packaging bags 101 to 106. Even in the case where the packaging bags 101 to 106 are formed, the high heat resistance can prevent the packaging bags 101 to 106 from being perforated or deformed. Therefore, it is possible to realize the packaging bags 104 to 106 for microwave heating and the packaged foods 204 to 206 which are excellent in functionality (suppression of influence on contents) and heat resistance.

In the laminated film 1a (FIG. 7A), since the barrier layer 14a is positioned on the outer side of the packaging bag (printed layer 12 side) in the intermediate layer 14, the barrier layer is not damaged or deteriorated due to rubbing or the like during lamination. . In addition, since the barrier layer 14a is arranged at a position far from the hot food F and close to the printed layer 12 and the adhesive layer 13 adjacent thereto, the residual organic solvent from the printed layer 12 and the like to the food F movement can be stopped at an early stage.

In the laminated film 1b (FIG. 7(B)), the barrier layer 14a is located inside the packaging bag (on the sealant layer 15 side) of the intermediate layer 14, so that the barrier layer 14a and the sealant layer 15 are not adhered to each other by the adhesive layer 13. It is stronger, and the lamination strength between the intermediate layer 14 and the sealant layer 15 of the laminated film 1b can be increased. Therefore, it is effective in improving impact resistance.

The polypropylene film forming the sealant layer 15 preferably has an elongation at break of 900% or more on average or a Young's modulus of 600 MPa or less on average. By forming the sealant layer 15 from a polypropylene film having such physical properties, it is possible to obtain high impact resistance without using a polyamide film, and to prevent bag breakage due to dropping. Moreover, since the number of laminates does not increase, it is effective in reducing the weight, thickness, and cost of the packaging bag.

Moreover, the polypropylene film constituting the sealant layer 15 preferably has a breaking elongation of 900% or more and a Young's modulus of 600 MPa or less in any direction on the film surface. By configuring the sealant layer 15 with a polypropylene film having such physical properties, it is possible to suppress damage to the packaging bags 101 to 106 regardless of the direction of impact. Therefore, high impact resistance can be stably obtained without using a polyamide film, and bag breakage due to various drops can be prevented. Moreover, since the number of laminates does not increase, it is effective in reducing the weight, thickness, and cost of the packaging bag.

Although the packaging bags 101 to 106 are standing pouches, the configurations of the vapor release mechanism 3 and laminated films 1a and 1b described above are not limited to this type, and can be applied to other types of packaging bags. For example, a flat pouch type packaging bag (for example, a three-sided seal type packaging bag) can obtain the same effect by using the steam release mechanism 3 and the laminated films 1a and 1b.

The packaging bag, packaged food, and the like according to the present invention will now be described in more detail with reference to Examples 1 to 4 and Comparative Examples 1 to 5. The schematic laminated structure of the laminated films 1a and 1b of Examples 1 to 4 and Comparative Examples 1 to 5 is arranged from the outside of the packaging bag to the inside of the packaging bag, with the base layer/printed layer (printed)/adhesive layer (DL)/intermediate layer. /adhesive layer (DL)/sealant layer format. However, the position of (coat) represents the position of the deposited film with respect to the PET film.
Example 1: PET12/print/DL/(coated) transparent VMPET12/DL/CPP60 (CPP film A)
Example 2: PET12/print/DL/(coated) transparent VMPET12/DL/CPP40 (CPP film A)
Example 3: PET12/printing/DL/clear VMPET12 (coated)/DL/CPP60 (CPP film A)
Example 4: PET12/print/DL/(coated) transparent VMPET12/DL/CPP60 (CPP film B)
Comparative Example 1: Transparent VMPET12 (coating)/printing/DL/ONY15/DL/CPP60 (CPP film B)
Comparative Example 2: Transparent VMPET12 (coating)/printing/DL/PET12/DL/CPP60 (CPP film B)
Comparative Example 3: PET/ON co-extruded film 15/print/DL/PET12/DL/CPP60 (CPP film B)
Comparative Example 4: Transparent VMPET12 (coating)/printing/DL/ONY15/DL/CPP60 (CPP film C)
Comparative Example 5: PET12/printing/DL/(coating) transparent VMPET12/DL/CPP35 (CPP film A)

The details of each layer in the general laminated structure are shown below.
PET12: polyethylene terephthalate (PET) film, thickness 12 μm
ONY15: biaxially oriented nylon, thickness 15 μm
Transparent VMPET12: Transparent vapor-deposited PET film, thickness 12 μm (water vapor barrier: 0.5 g/m ² ·day, oxygen barrier: 0.5 cc/m ² ·atm · day)
PET/ON coextruded film 15: biaxially oriented nylon laminated with PET, total thickness 15 μm
CPP60: Unstretched polypropylene (CPP) film, thickness 60 μm
CPP40: Unstretched polypropylene (CPP) film, thickness 40 μm
CPP35: Unstretched polypropylene (CPP) film, thickness 35 μm
Printing... Printing ink: general ink (urethane ink)
DL... Adhesive: general adhesive for dry lamination (ester type), manufactured by Rock Paint Co., Ltd. Main agent R-004/Hardener H-1

Table 1 shows the physical properties of the CPP films A, B, and C in the MD direction (Machine Direction: film flow direction) and TD direction (Transverse Direction: film width direction), together with their average values. The elongation at break (%) is the result of measurement using the JIS K7127 method, and the Young's modulus (MPa) is the result of measurement using the JIS K7127 method. As shown in FIG. 1 and the like, the MD direction coincides with the easy-to-tear linear direction of the sheets 1A and 1B (the breaking direction from the notch 4n).

Table 2 shows the evaluation results of functionality, heat resistance (suitability for microwave ovens) and impact resistance of Examples 1 to 4 and Comparative Examples 1 to 5.

Sensory evaluation (sensory test of taste and smell): 5 stand-type packaging bags (standing pouches shown in FIG. 1) with a height of 150 mm, a width of 160 mm, and a gusset height of 45 mm, porridge ( 100 g of white porridge) was added, retorted at 120° C. for 30 minutes, allowed to stand for 24 hours, and then heated in a microwave oven at 500 W until steamed. Five panelists compared the difference in taste and smell between the porridge and the blank, and sensory evaluation was given as if there was a difference in at least one of the porridges. In the sensory column of Table 2, the case where 4 or more persons judged no abnormality was indicated by ◯, and the case where 3 or less persons judged no abnormality was indicated by x.

Heat resistance evaluation (whether it can withstand microwave heating until steaming): Five stand-type packaging bags (standing pouches shown in FIG. 1) with a height of 150 mm, a width of 160 mm, and a gusset height of 45 mm, food ( Contents) As F, 100 g of Doteni (manufactured by Ichibiki Co., Ltd.) was added, subjected to retort treatment at 120° C. for 30 minutes, left for 24 hours, and then heated in a microwave oven at 500 W until steamed. The presence or absence of abnormality (perforation or deformation) was confirmed for at least one piece. In the column of heat resistance in Table 2, ◯ indicates no abnormality, Δ indicates slight abnormality such as deformation, and x indicates obvious abnormality such as perforation.

Impact resistance evaluation: Five stand-type packaging bags (standing pouches shown in Fig. 1) having a height of 180 mm, a width of 170 mm, and a gusset height of 50 mm were filled with 400 ml of water as food (contents) F, and the temperature was 120°C and 30°C. After 24 hours of retort treatment, 10 sets of vertical drop and horizontal drop from a height of 1.0 m were performed. Impact resistance was evaluated by the number of times until at least one bag broke. In the column of impact resistance in Table 2, ◯ indicates 10 times with no abnormality, Δ indicates 5 to 9 times without abnormality, and × indicates 1 to 4 times without abnormality.

From the difference in the sensory evaluation results between Example 4 and Comparative Example 2, it can be seen that at least the elution of the residual organic solvent in the printed layer 12 is suppressed by the barrier layer 14 a in the intermediate layer 14 . Regarding the heat resistance evaluation results, the difference between Comparative Examples 1 and 2 and the difference between Comparative Examples 2 and 3 indicate that the use of the PET film instead of the polyamide film has the effect of improving the heat resistance. I understand. As for the evaluation results of impact resistance, the difference between Example 1 and Example 4 shows the effect of improving impact resistance by forming the sealant layer 15 with CPP films having different physical properties.

1a, 1b laminated film 1A front sheet (laminated film)
1B back sheet (laminated film)
1C bottom sheet (laminated film)
2 Housing space 3 Steam release mechanism 3a Protruding seal portion 3b Point seal portion 3H Planned steaming area 3h Hole portion 3s Notch portion 4 Body seal portion 4a, 4b Unsealed portion 4c Ventilation chamber 4n Notch 5 Bottom seal portion 6 Top seal portion 6h Opening 11 Base layer 12 Printed layer 13 Adhesive layer 14 Intermediate layer 14a Barrier layer 14b Resin layer 15 Sealant layer 101-106 Packaging bag 201-206 Packaged food F Food (contents)
V steam

Claims (7)

A microwave oven heating packaging bag made by heat-sealing a laminated film so that a storage space for storing contents is formed inside the packaging bag,
Equipped with a steam release mechanism for releasing steam in the accommodation space during microwave heating,
The laminated film comprises, from the outside of the packaging bag to the inside of the packaging bag, a substrate layer made of a polyester film, a printed layer, an intermediate layer made of a polyester film having a barrier layer, and a sealant made of a heat-adhesive polypropylene film. having a laminated structure including a layer and
A packaging bag, wherein the polypropylene film has an average elongation at break of 900% or more. A microwave oven heating packaging bag made by heat-sealing a laminated film so that a storage space for storing contents is formed inside the packaging bag,
Equipped with a steam release mechanism for releasing steam in the accommodation space during microwave heating,
The laminated film comprises, from the outside of the packaging bag to the inside of the packaging bag, a substrate layer made of a polyester film, a printed layer, an intermediate layer made of a polyester film having a barrier layer, and a sealant made of a heat-adhesive polypropylene film. having a laminated structure including a layer and
A packaging bag, wherein the polypropylene film has a breaking elongation of 900% or more and a Young's modulus of 600 MPa or less in any direction on the film surface. 3. The packaging bag according to claim 1, wherein the barrier layer is positioned outside the packaging bag in the intermediate layer. 3. The packaging bag according to claim 1, wherein the barrier layer is positioned inside the packaging bag in the intermediate layer. The packaging bag according to any one of claims 1 to 4, wherein the polypropylene film has a thickness of 40 µm or more and 80 µm or less. The packaging bag according to any one of claims 1 to 5, wherein the content is 400g or less. A packaged food for microwave heating, wherein the packaging bag according to any one of claims 1 to 6 is sealed and packaged in a state in which the food as the content is accommodated in the accommodation space. A packaged food product characterized by:

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