JP2007191199A - Packaging bag for use in microwave oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging bag for use in a microwave oven which packaging bag retains its bursting strength in a given range to exert a sealing property that is durable against pressure or impact applied to the bag during transportation or storage and also an opening property that allows quick venting of steam in heat cooking with the microwave oven, and can hermetically package a solid, liquid, or viscous content article to enable sanitary and safe heat cooking. <P>SOLUTION: The packaging bag 1 for use in the microwave oven has a peripheral sealed portion which is made by heat sealing the peripheries of sealant faces counter to each other, and an overhanging sealed portion 9 which is formed to overhang the peripheral sealed portion. The overhanging sealed portion 9 includes an unsealed portion 19 and a steam venting opening 18 which exhausts steam produced by heating with the microwave oven. The bursting strength of the packaging bag 1, which is measured according to "container bursting strength test" stipulated in JIS Z 0238, is 30 to 60 kPa. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a packaging bag for a microwave oven that can automatically reduce the internal pressure by releasing steam to the outside of the bag without rupturing the bag in which the contents are packaged when heated in a microwave oven.
More specifically, by maintaining the burst strength of the microwave oven packaging bag within a predetermined range, it can withstand pressure and impact applied during transportation and storage, and steam when cooking in a microwave oven. It is related with the packaging bag for microwave ovens which can exhibit both the characteristic of opening property which can discharge | emit quickly.

In recent years, with the widespread development of microwave ovens, and in response to the demand for simplified cooking, cooked processed foods are packaged in plastic packaging bags, etc., sealed, and distributed in a preservative form. Yes.
However, when such foods are heated in a microwave oven, if the packaging bag remains sealed, the internal pressure in the bag increases due to the water vapor generated from the contents by heating, and eventually the contents are ruptured. It was often scattered in the range.
As a packaging container for preventing such a rupture of the packaging bag, the present applicant, prior to the filing of the present application, uses a composite film composed of a sealant layer on at least one surface, a lower member having the sealant surface as an upper surface, and a sealant. A packaging bag in which the wings are formed with the sides facing each other and the side and tip sides are sealed, and the upper member with the sealant surface as the bottom is overlapped, and the periphery is sealed and sealed as the main seal A point seal portion is provided in an area in the wing portion, and at least one easy-to-vaporize means is provided in the point seal portion, and the point seal portion has a circle centered on the center portion of the pouch. Configured so that when drawn, the radius of the circle that touches the bottom edge of the point seal part from the center of the pouch is shorter than the radius of the circle that touches the inner edge of the side seal part It discloses a microwave packaging bag for which (for example, see Patent Document 1).
Prior to the filing of the present application, the present applicant inserts the bottom surface of the quadrangle that constitutes the trunk part into the bottom and the rear surface by folding the bottom surface in an inverted V shape and inserting the front surface, the rear surface, and the peripheral edge of the bottom surface. The self-supporting packaging bag is formed in such a manner that the top part, the body part, and the bottom part are formed by heat-sealing, and the bottom part expands back and forth with the filled contents so that it can stand on its own. And providing an overhanging seal portion connected to the top seal portion or the trunk seal portion, and providing at least one evaporating means in the overhang seal portion, and the overhang seal portion is the center of the pouch. For microwave ovens configured so that the radius of the circle that touches the bottom edge of the point seal part from the center of the pouch is shorter than the radius of the circle that touches the inner edge of the side seal part when a circle centered on the part is drawn Packaging Discloses (for example, see Patent Document 2).
JP 2003-155071 A JP 2005-59872 A

However, in the conventional microwave packaging bag, the heat sealing strength at which the packaging bag opens when cooking with a microwave oven, that is, the “rupture strength of the packaging bag” tends to vary, and when cooking with a microwave oven, There is a problem in that the packaging bag is unnecessarily opened and the packaging bag swells more than necessary, and the bag is broken and the contents are scattered in the microwave oven.
In addition, if the bursting strength is made too small in order to provide an opening function that allows steam to be quickly discharged from the above-described easy-vaporizing means when cooking in a microwave oven, the weight of the contents cannot be withstood. It cannot withstand the pressure or impact applied when transporting or storing a sealed package that has been heat-sealed after the bag has been broken or filled with the contents, and the contents cannot be withheld during transportation or storage. There is a problem that it cannot withstand use as a packaging bag because it causes liquid leakage or bag breakage.

  Therefore, the object of the present invention is to maintain the burst strength of the microwave packaging bag within a predetermined range, so that it can withstand pressure and impact applied during transportation and storage, and cooking with a microwave oven. It is possible to exert both the characteristics of opening and the ability to expel steam quickly, and the contents of solids, liquids, and viscous bodies can be hermetically sealed and peeled off by pressure and impact applied during transportation and storage Even if heated in a microwave oven, the steam can be automatically discharged outside the bag to reduce the internal pressure, it can be cooked hygienically and safely, and the packaging bag for microwave ovens has excellent display effects at stores Is to provide.

  In order to solve the above-mentioned problems, the microwave oven packaging bag according to the present invention is a packaging bag for heating by a microwave oven, and uses a laminated film having at least one surface composed of a sealant layer, and sealant surfaces are bonded to each other. It is formed as a peripheral seal part by heat-sealing the peripheral part so as to face each other, and is formed as an overhanging seal part protruding from the peripheral seal part, and steam generated when heating in the unsealed part and the microwave oven in the overhanging seal part In a packaging bag provided with a steam outlet for discharging outside the bag, the bursting strength of the packaging bag measured in accordance with the “test for bursting strength of containers” in Japanese Industrial Standard JIS Z 0238 is 30 kPa or more and 60 kPa or less. It is the packaging bag for microwave ovens characterized by being in the range.

  In the microwave oven packaging bag of the present invention, in the above configuration, the peripheral seal portion and the overhang seal portion have a seal strength at normal temperature of 23 N / 15 mm or more, and the overhang seal portion A microwave oven packaging bag having a sealing strength at 100 ° C. in a range of 9.8 N / 15 mm or more and less than 23 N / 15 mm.

  Further, the microwave packaging bag of the present invention, in any one of the above configurations, the packaging bag is a lower member having the sealant surface as an upper surface, and the side portion and the tip side portion with the sealant surfaces facing each other. Is formed as a peripheral seal portion by sealing the peripheral portion thereof, and the overhang seal portion is formed in the wing portion, It is a packaging bag for microwave ovens provided with the above-mentioned unsealed part and the above-mentioned steaming opening in the above-mentioned overhanging seal part.

  The microwave packaging bag according to the present invention may further include the packaging bag according to any one of the above-described configurations, wherein the packaging bag is folded in a reverse V shape on the front surface and the bottom surface of the quadrangle constituting the body portion. Inserting and heat-sealing the front edge, the rear face, and the peripheral edge of the bottom face to form a peripheral seal part, forming the overhang seal part above the packaging bag, and in the overhang seal part It is a self-supporting packaging bag provided with the said non-seal part and said steaming opening, It is a packaging bag for microwave ovens characterized by the above-mentioned.

In the microwave oven packaging bag of the present invention, it is used for hermetically wrapping the contents of solid, liquid, and viscous materials, and transport by keeping the bursting strength of the microwave oven packaging bag within a predetermined range. In addition, it has a sealing property that can withstand the pressure and impact applied during storage, and there is little variation in the opening that can discharge steam when cooking with a microwave oven, so that steam can be discharged quickly and safely and hygienically. Can be cooked.
Further, the microwave oven packaging bag of the present invention has the advantages that it has self-supporting stability, can easily and safely transfer contents, has an excellent display effect at a store, and can be sealed with high productivity.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of the microwave packaging bag 1 of the present invention, and FIG. 2 is a plan view showing another embodiment of the microwave packaging bag 1 of the present invention. 3 is a cross-sectional view of a laminate 10 of a packaging material that forms the packaging bag 1 for a microwave oven of the present invention, and FIG. 4 is a cross-sectional view of another laminate 10 of the packaging material that forms the packaging bag. FIG. 5 is a diagram showing the shapes of the steam openings 17 and 18.

FIG. 1 is a perspective view showing an embodiment of a packaging bag 1 for a microwave oven according to the present invention.
As shown in FIG. 1, a packaging bag 1 for a microwave oven according to the present invention is inserted into a bottom part of a front face 2 and a rear face 3 that form a body part by folding a bottom face 4 in an inverted V shape. 2, the rear surface 3 and the bottom surface 4 are heat sealed to form a body seal portion 5 and a bottom seal portion 6, and after filling the contents, the top seal portion 7 is heat sealed and sealed. It is a self-supporting packaging bag in which the bottom surface 4 can expand and contract independently by the filled contents.
Further, the microwave packaging bag 1 according to the present invention is provided with an overhang seal portion 9 connected to the trunk seal portion 5, and an unsealed portion 19 surrounded by the overhang seal portion 9 is cut as shown in FIG. 17 or a packaging bag having a configuration that forms a notch 18 or the like.
As a result, the overhanging seal 9 is peeled and retracted by the heat and pressure of the steam generated by heating, and the steam is diffused from the notch 17 or the notch 18 so that the natural opening is performed.
Moreover, since the packaging bag 1 of the present invention can be heated in a microwave oven in a self-supporting state, it can also be used for fluid food.
Further, since the notch 17 or the notch 18 is inside the overhanging seal portion 9, the sealing performance can be completely maintained in the distribution stage.
Furthermore, in the present invention, the packaging bag 1 needs to have a burst strength in the range of 30 kPa to 60 kPa.
As a result, it has a sealing property that can withstand pressure and impact applied during transportation and storage, and there is little variation in the opening that can discharge steam when cooking with a microwave oven, so steam can be discharged quickly. It can be cooked safely and hygienically.
If the burst strength of the packaging bag 1 is less than 30 kPa, the package cannot withstand the weight of the contents, or the packaging bag is filled with the contents and then heat sealed and sealed for transport and storage. This is not preferable because it cannot withstand the pressure and impact applied during the operation, and the contents may leak during transportation or storage, resulting in a broken bag.
If the burst strength of the packaging bag 1 exceeds 60 kPa, it will not be opened quickly when cooking with a microwave oven, the packaging bag will swell more than necessary, the bag will break and the contents will scatter in the microwave oven. This is not preferable because it gives the consumer a fear of losing the bag depending on the heating conditions and contents.

In the present invention, the microwave packaging bag 1 according to the present invention is not limited to the standing pouch shown in FIG. 1, and includes, for example, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, and an envelope-attached seal type. To produce various types of packaging bags according to the present invention by heat-sealing with a heat-sealing type such as a gas-sealed seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a gusset type, etc. Can do.
The packaging bag 1 of various forms as described above uses a laminated body composed of at least the inner sealant layer 13 and folds the inner surface of the inner sealant layer 13 facing each other. A bag body can be formed by stacking two sheets and further heat-sealing the peripheral end portion to provide a seal portion.
In the case of the microwave packaging bag 1 according to the present invention, in the case of a flat packaging bag other than a self-supporting bag, an exterior packaging box is used, and the packaging bag is accommodated in the packaging bag so as to assist the packaging bag independence. It is possible to cook in a microwave oven.

In the microwave packaging bag 1 according to the present invention, the overhang seal portion 9 shown in FIG. 1 can be integrally sealed with the body seal portion 5 when forming the seal portion on the periphery, so that the productivity is high. It can be sealed.
On the other hand, when the projecting seal portion 9 is not connected to the body seal portion 5 and is formed independently, the pressure of the steam generated by heating of the microwave oven is increased. Or the top seal portion 7 and the independent seal portion formed independently of each other, it is difficult to efficiently apply pressure to the independent seal portion, and it is not preferable because automatic opening does not occur smoothly. . Furthermore, when the contents are filled or in the course of distribution, the contents enter between the independent seal portion and the body seal portion 5 or the top seal portion 7 to cause an appearance defect. Further, since the independent seal portion and the peripheral seal portion of the body seal portion 5 and the top seal portion 7 are sealed in two steps, the productivity of the seal processing is inferior, which is not preferable.

Next, in the microwave packaging bag 1 according to the present invention, as shown in FIG. 1, when the overhanging seal portion 9 is formed in a circle around the center of the packaging bag, the packaging bag 1 is formed. The radius r3 of the circle in contact with the lowermost end of the projecting seal portion 9 from the center of the center is shorter than the radius r1 of the circle in contact with the inner edge of the body seal portion 5 and the radius r2 of the circle in contact with the inner edge of the top seal portion 7. It is necessary to provide in position.
On the other hand, if the radius r3 is longer than the radius r1 or the radius r2, the internal pressure rises due to heating of the microwave oven, so that the internal pressure is applied to the body seal portion 5 and the top seal portion 7 which are the peripheral seal portions of the packaging bag. As a result, the body seal part 5 and the top seal part 7 are peeled and retracted, and the contents may leak due to the broken bag of the packaging bag.

Next, in the microwave packaging bag 1 according to the present invention, as shown in FIG. 1, the protruding seal portion 9 preferably has a protruding end 20 that protrudes from the bottom end of the seal portion.
In addition, if the protrusion 20 is formed, it is not limited to an overhang, and although not shown, a trapezoidal shape or a triangular shape may be used.
This is preferable because the internal pressure due to heating is likely to be concentrated on the tip, and the peeling and retreat of the seal portion proceeds reliably and smoothly starting from the tip 20.
On the other hand, when the shape of the overhanging seal portion 9 is circular or semicircular with no corners, the internal pressure generated by heating is dispersed, and more pressure is required to peel and retract the seal portion. For this reason, it is difficult to peel off smoothly, and a larger pressure is applied to portions other than the overhanging seal portion 9, which is not preferable.
The seal width of the overhanging seal portion 9 is preferably about 2 mm to 5 mm because the seal can be smoothly peeled off by internal pressure due to heating.
On the other hand, if the seal width of the overhanging seal portion 9 is less than 2 mm, the seal strength becomes unstable, which is not preferable. If it exceeds 5 mm, it is difficult to peel off the seal smoothly due to internal pressure due to heating.
Further, in the microwave packaging bag 1 of the present invention, the peripheral seal portion, that is, the seal width of the body seal portion 5, the bottom seal portion 6 and the top seal portion 7 is about 5 mm to 20 mm. It is preferable because it is not broken by pressure or impact applied during storage.

Further, in the microwave packaging bag 1 according to the present invention, by forming the unsealed portion 19 surrounded by the overhanging seal portion 9, the positions where the steam ports 17 and 18 formed in the unsealed portion 19 are formed. Even if the seal is displaced, the distance at which the seal peels and retreats is constant, and when the peeling reaches the unsealed portion 19, the opening (notch 17 and notch 18) formed in the unsealed portion 19 is opened wide at once. Therefore, when heating in a microwave oven, there is an advantage that reliable, stable and quick steam removal can be performed.
On the other hand, if the unsealed part 19 surrounded by the overhanging seal part 9 is not formed and only the solid seal is formed, the seal peeling and retreating may occur when the position where the steaming opening (the notch 17 and the notch 18) is shifted. The distance is changed, and as a result, it is not preferable because stable seal peeling is not always performed.
In addition, since this steaming opening (the notch 17 and the notch 18) is on the inner side surrounded by the overhanging seal part 9 and the trunk part seal part 5, it can maintain completely hermeticity at the distribution stage and is hygienic. .

Next, in the microwave packaging bag 1 according to the present invention, it is necessary to form the notch 17 or the notch 18 in the unsealed portion 19 in the overhang seal portion 9 as a steaming opening.
By forming the steaming opening, the internal pressure rises due to the heating of the microwave oven, and then peels and retreats from the lowermost end of the overhanging seal portion 9 to reach the unsealed portion 19 and is formed in the unsealed portion 19. The vapor filled in the bag is diffused to the outside through the bag, the internal pressure of the bag can be reduced, and rupture can be avoided.
Next, the shape of the steaming opening formed in the unsealed portion 19 surrounded by the overhanging seal portion 9 is not particularly limited, and for example, as shown in FIG. 5, a cross-shaped, I-shaped, U-shaped or the like is cut. 18 or a cutout 17 such as a circle, a triangle, or a rectangle can be formed.
The number of the notches 17 or the notches 18 is not limited to one and may be plural.
Moreover, the notch 17 or the notch 18 which is a steaming opening may be provided so that it may penetrate through the two members which comprise the opposing trunk | drum, or may be provided only in one side.
The notch 17 or the notch 18 can be formed by laser processing or punching.
It should be noted that the inside of the overhanging seal portion 9 may be a pattern seal portion instead of being unsealed.
The seal shape of the pattern seal portion is not particularly limited, and examples thereof include a mesh shape, a lattice shape, a stripe shape, and a polka dot shape.

Further, in the microwave packaging bag 1 according to the present invention, the size of the hole of the notch 7 which is a steaming opening in the present invention is 12 mm ² (hole diameter: 4 mmφ) or more and 51 mm ² (hole diameter: 8 mmφ). ) If the internal pressure increases due to heating in the microwave oven, and the pressure inside the microwave oven bag body exceeds a predetermined level due to cooking, it is promptly released from the steaming openings 7 and 8 of the microwave packaging bag 1 It is preferable because the vapor can escape and the contents can be prevented from blowing out of the bag.
In contrast, the pore size of蒸通port 17, 12 mm ² (pore diameter: 4 mm diameter) is less than, is not preferred because if there is the contents are discharged from the outer bag, 51 mm ² (diameter holes : 8 mmφ) is not preferable because it is difficult for the steam to escape smoothly due to the internal pressure due to heating.

FIG. 2: is a top view which shows the Example of another aspect of the packaging bag 1 for microwave ovens of this invention.
As shown in FIG. 2, the microwave packaging bag 1 according to the present invention is provided with a wing portion 23 on one side of the bag, and a steam port for discharging steam is formed in the central region of the wing portion 23. As a means for achieving this, the overhanging seal portion 16 is provided, and further, the inside of the overhanging seal portion 16 is a packaging bag having a configuration in which a notch 17 and a notch 18 as shown in FIG. 5 are formed.
As a result, the overhanging seal portion 16 peels and retreats due to the heat and pressure of the steam generated by heating, and the steam is released from the notch 17 or the notch 18 so that the natural opening is performed. Moreover, since the packaging bag 1 of this invention can be placed horizontally and can be heated by a microwave oven, it can respond also to fluid food.
Further, since the notch 17 or the notch 18 is inside the overhanging seal portion 16, it is possible to completely maintain the sealing performance at the distribution stage.
Furthermore, in the present invention, the packaging bag 1 needs to have a burst strength in the range of 40 kPa to 60 kPa.
With this, it has a sealing property that can withstand the pressure and impact applied when transporting and storing, and there is little variation in the opening property that can discharge steam when cooking with a microwave oven, and steam can be discharged quickly, It can be cooked safely and hygienically.
If the rupture strength of the packaging bag 1 is less than 40 kPa, the package cannot withstand the weight of the contents, or the packaging bag is filled with the contents and then heat sealed and sealed for transport and storage. This is not preferable because it cannot withstand the pressure and impact applied during the operation, and the contents may leak during transportation or storage, resulting in a broken bag.
If the burst strength of the packaging bag 1 exceeds 60 kPa, it will not be opened quickly when cooking with a microwave oven, the packaging bag will swell more than necessary, the bag will break and the contents will scatter in the microwave oven. This is not preferable because it gives the consumer a fear of losing the bag depending on the heating conditions and contents.

The packaging bag 1 for a microwave oven of the present invention uses a plastic film having at least one side made of a sealant layer, and as shown in FIG. 2, forms a wing portion 23 in which the sealant layers of the upper member are opposed to each other, This is a packaging bag in which the sealant layer of the upper member and the sealant layer of the lower member are overlapped, and the periphery is sealed to form the periphery seal portion 24 and sealed.
The method for forming the packaging bag of the present invention in which the wing portion 23 is provided may be a method of folding the wing portion using the upper member as one piece in addition to the above-described three-piece method.
It should be noted that the inside of the overhanging seal portion 16 may be a pattern seal portion instead of being unsealed.
The seal shape of the pattern seal portion is not particularly limited, and examples thereof include a mesh shape, a lattice shape, a stripe shape, and a polka dot shape.
Furthermore, as a self-supporting assisting means, although not shown, a sleeve-like cardboard having a shape that exposes the steaming means formed on the packaging bag is used, and the self-supporting function of the packaging bag is stored in the sleeve-like cardboard. You can also help.

As shown in FIG. 2, the position where the overhanging seal portion 16 is formed is a radius r5 of a circle in contact with the lowermost end of the overhanging seal portion 16 from the center of the packaging bag when a circle centered on the center portion of the packaging bag is drawn. Is provided at a position shorter than the radius r4 of the circle in contact with the inner edge of the side seal portion.
When the radius r5 is longer than the radius r4, the peeling and retreating of the seal part due to the heat of steam generated by heating and the increase of the internal pressure becomes the peeling at the side seal part of the packaging bag, and the package bag breaks and the contents leak. There is a fear.

  As for the position of the wing part provided in the microwave packaging bag of the present invention, a / b shown in FIG. 2 is preferably 2/5 or less. If it is larger than this, the overhanging seal part 16 provided in the wing part 23 has a peeling and retreating force. Does not work well and automatic opening is not achieved.

  Further, as shown in FIG. 2, the distance d between the lower end portion of the easy-evaporating means (illustrated as an example of cutting) provided in the overhang seal portion 16 and the lower end portion of the overhang seal portion 16 is preferably in the range of 3 to 10 mm. Is 2-8 mm. If the distance is less than 2 mm, the strength against vibration, dropping, etc. is weakened, and there is a possibility that the bag will be broken during the distribution of the product. If the distance is greater than 10 mm, it is difficult for steam to escape and bag breakage from other seals may occur.

The microwave packaging bag 1 of the present invention preferably has a seal strength of the peripheral seal portions 5, 6, 7, and 24 and the overhang seal portions 9 and 16 of 23 N / 15 mm or more at room temperature. The seal strength at 100 ° C. of the portions 9 and 16 is preferably in the range of 9.8 N / 15 mm or more and less than 23 N / 15 mm.
A seal strength of 23 N / 15 mm or more at normal temperature is preferable because it can be used without being peeled off due to pressure or impact applied during transportation or storage. The seal strength is 9.8 N / 15 mm at a temperature of 100 ° C. or more. As mentioned above, by setting it as the range of less than 23N / 15mm, retort processing is possible and it can be made to open automatically safely with the vapor | steam which generate | occur | produces also in the case of a high output microwave heating.

Next, FIG. 3 is a cross-sectional view of a laminate 10 of packaging materials that forms the microwave packaging bag 1 of the present invention.
As shown in FIG. 3, the laminate 10 forming the microwave packaging bag of the present invention is one in which a base material layer 11 and a sealant layer 13 are sequentially laminated via an adhesive layer 12.
Note that the adhesive layer 13 is not an essential layer, but is a layer provided as necessary.
In addition, as shown in FIG. 3, an intermediate layer 14 and a printing layer 15 may be provided between the base material layer 11 and the sealant layer 13 as necessary.

Next, the constituent material of the laminated body 10 which forms the packaging bag 1 for microwave ovens of this invention is demonstrated.
First, the base material layer 11 is not particularly limited as long as it has heat resistance and is generally used as a packaging material for food that is heated or cooked in a microwave oven.
For example, stretched polyethylene terephthalate film, silica-deposited stretched polyethylene terephthalate film, alumina-deposited stretched polyethylene terephthalate film, stretched nylon film, silica-deposited stretched nylon film, alumina-deposited stretched nylon film, stretched polypropylene film, polyvinyl alcohol-coated stretched polypropylene film, nylon 6 / Metaxylylenediamine nylon 6 co-extrusion co-stretched film or polypropylene / ethylene-vinyl alcohol copolymer co-extrusion co-stretched film or the like, or a composite film obtained by laminating two or more of these films may be used.
These substrate layers may be single layers or multilayers (laminates), have a melting point and heat resistance of 150 ° C. or higher, and have a thickness of about 10 μm to 50 μm, preferably about 10 μm to 30 μm.

The resin constituting the sealant layer 13 in the present invention is not particularly limited as long as it is a heat-adhesive resin layer and is generally used as a food packaging material heated or cooked in a microwave oven.
For example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid A resin such as a copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, or an ionomer can be used.
The sealant layer may be formed by extrusion lamination of these resins, or laminated in advance by a heat resistant substrate layer and dry lamination or extrusion lamination as a film formed by T-die method or inflation method. May be.
The thickness of the sealant layer is preferably about 20 μm to 100 μm, and more preferably 40 μm to 70 μm. The state of seal retraction is not particularly defined, but cohesive failure is preferred.
Further, the seal strength between the overhang seal portion 9 and the peripheral seal portion, that is, the trunk seal portion 5, the bottom seal portion 6 and the top seal portion 7 may be different, but in the present invention, there is no necessity. Even with the same strength, the automatic opening is achieved by the shape described above.
Furthermore, the sealant layer 13 has a sufficient sealing strength especially at low temperatures (0 ° C.) and normal temperatures (25 ° C.), and has a low sealing strength when heated in a microwave oven (100 ° C. or higher), and can be peeled off quickly. It is preferable to use a heat-adhesive resin layer comprising a resin composition containing a propylene-ethylene block copolymer resin as a main component.
The blending ratio of each composition of the mixed resin is as follows. The propylene-ethylene block copolymer (A) as the first component, the propylene-ethylene block copolymer (B) as the second component, and the third component An ethylene-butene-1 copolymer containing 15% by weight or more of butene-1 is an essential component, and the propylene-ethylene block copolymer (A) as the first component is a propylene homopolymer or ethylene. 65 to 85% by weight of propylene block (I) made of propylene-ethylene copolymer having a content of 2% by weight or less, and 15 to 35% by weight of ethylene-propylene copolymer block (II) having an ethylene content of 20 to 95% by weight The propylene-ethylene block copolymer (B) as the second component is a propylene homopolymer or ethylene content. 85 to 95% by weight of propylene block (III) comprising propylene-ethylene copolymer of 2% by weight or less, and 5 to 15% by weight of ethylene-propylene copolymer block (IV) having ethylene content of 20 to 95% by weight It is appropriate to use within a range.

Next, lamination | stacking with the base material layer 11 and the sealant layer 13 will not be specifically limited if it is methods, such as a coextrusion laminating method and a dry laminating method.
The adhesive layer 12 is an adhesive by lamination or an adhesive resin layer.
In the above, as the laminating adhesive, for example, one-part or two-part curable or non-cured vinyl type, (meth) acrylic type, polyamide type, polyester type, polyether type, polyurethane type, epoxy type, etc. It is possible to use adhesives for laminating such as rubber type, other solvent type, aqueous type, or emulsion type.
As a coating method of the adhesive for laminating, for example, direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fountain method, transfer roll coating method, and other methods can be used. .
As the coating ^{amount, 0.1g / m 2 ~10g / m} 2 ( dry state) position are ^{preferred, 1g / m 2 ~5g / m} 2 ( dry state) position is more preferred.
In the above, a resin layer made of a thermoplastic resin layer is used as the adhesive resin layer, and can be used for bonding the respective layers.

Specifically, the material of the adhesive resin layer includes a low density polyethylene resin, a medium density polyethylene resin, a high density polyethylene resin, a linear low density polyethylene resin, and ethylene / α-olefin polymerized using a metallocene catalyst. Copolymer resin, ethylene / polypropylene copolymer resin, ethylene / vinyl acetate copolymer resin, ethylene / acrylic acid copolymer resin, ethylene / ethyl acrylate copolymer resin, ethylene / methacrylic acid copolymer resin, Graft polymerization of unsaturated carboxylic acid, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, ester monomer to ethylene / methyl methacrylate copolymer resin, ethylene / maleic acid copolymer resin, ionomer resin, polyolefin resin, Or graft copolymerized resin, maleic anhydride to polyolefin resin It can be used sexual resin or the like.
These materials can be used alone or in combination.
The thickness of the resin layer is preferably about 10 to 30 μm.

Furthermore, in this invention, you may provide the intermediate | middle layer 14 between the base material layer 11 and the sealant layer 13, and the intermediate | middle layer 14 is the function as the packaging bag 1 only by the base material layer 11 and the sealant layer 13 normally. It is provided when it is not possible to sufficiently fulfill the above.
The above functions include gas barrier properties, mechanical toughness, bending resistance, puncture resistance, impact resistance, wear resistance, cold resistance, heat resistance, chemical resistance, etc., which are required as a packaging bag 1 These functions are achieved by providing the intermediate layer 14 as an intermediate layer 14.

Examples of the base material used as the intermediate layer 14 include polyolefins such as polyethylene terephthalate, polyamide, polyethylene, and polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer. A film such as a saponified product, a film obtained by coating polyvinylidene chloride on these films, a film obtained by depositing an inorganic substance such as silicon oxide or aluminum oxide, or a film such as polyvinylidene chloride can be used.
One or more of these substrates can be used in combination.
It should be noted that the thickness of the base material only needs to satisfy the function required for the package, and can be appropriately selected as necessary.
In addition, when performing said lamination | stacking, if necessary, it can laminate | stack by performing pretreatments, such as a corona treatment, an ozone treatment, a flame | frame treatment, etc., for example.

  The above-mentioned surface pretreatment is carried out as a method for improving the adhesion and the like when laminating each resin film or sheet and each layer. As a method for improving the above adhesion, for example, A primer coat agent layer, an undercoat agent layer, an anchor coat agent layer, and the like can be arbitrarily formed in advance on the surface of various resin films or sheets to form a surface treatment layer.

Furthermore, in this invention, it is preferable to form the notch 22 in the edge of the trunk | drum seal | sticker part 5 of the packaging bag 1 for microwave ovens.
In this case, it is preferable to use a stretched film having a tearing directionality that is easy to tear laterally through the notch 22.

  In the above, as a heat sealing method, for example, a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal, or the like can be used.

Although not shown in the drawings, the microwave packaging bag 1 of the present invention can be formed as a holding means by forming a wide seal portion on the lower body seal portion 5 below the overhang seal portion.
Thus, when the packaging bag is taken out after being heated in the microwave oven, the consumer is not burned by the steam released from the steaming ports 17 and 18 in the overhanging seal portion 9, and the wide seal portion has the contents. Since it does not become hot compared with the surface part of the bag film in contact with the bag, it can be taken out safely and reliably.
In addition, as a seal width of the wide seal portion, about 10 mm to 20 mm is preferable because it can be taken out safely and reliably when the consumer takes out the packaging bag after heating with a microwave oven.

  Although not shown, the packaging bag 1 can be filled with liquid contents in addition to the solid contents. For example, solid foods such as frozen sushi, curry, soup, soy sauce, A variety of fluid foods such as sauces, soups, spices, cooking liquors, fruit juices, and water, and food and drinks can be filled and packaged. Can be cooked for a certain period of time, only the steam generated by heating can be quickly discharged, the internal pressure can be reduced automatically, and it can withstand the pressure and impact applied during transportation and storage. In addition to having a sealing property, there is little variation in the opening that can discharge steam when cooking in a microwave oven, and it has excellent independence and can be safely removed from the microwave oven without being burned by holding means. , Easily and safely easily transferred the contents, excellent display effect in the shop, in which excellent productivity can be sealed processing.

The microwave packaging bag of the present invention will be described more specifically with reference to examples.
As the packaging bag 1, a 12 μm thick silica-deposited polyethylene terephthalate film, a 15 μm stretched nylon film, and a 70 μm unstretched polypropylene film are dry-laminated and layered from the outside, a stretched polyethylene terephthalate film (12 μm) / silica deposition A laminated film 10 of layer / adhesive layer / stretched nylon film (15 μm) / adhesive layer / unstretched polypropylene film (70 μm) was produced.
Using the laminated film 10 obtained above, the body part is formed by heat-sealing the side edge portions of the two wall films of the front surface 2 and the rear surface 3 with the body seal part 5, and the body seal part 5 And the overhanging seal portion 9 is integrally formed. Further, after one steaming port 18 is provided in the unsealed portion 19 surrounded by the overhanging seal portion 9, the film on the bottom surface 4 is folded inside. Formed in a gusset form, the bottom seal portion 6 was heat-sealed with a boat bottom-shaped seal pattern to produce a microwave oven packaging bag 1 according to the present invention as shown in FIG. (External dimensions, height: 145 mm x width: 155 mm, vertical dimension of overhang seal part: 15 mm x horizontal dimension: 35 mm, notch diameter: 5 mm, seal width of overhang seal part: 3 mm, seal width of peripheral seal part: 10 mm (Dimension from top seal part 7 to overhang seal part 9: 48 mm)
The unstretched polypropylene film surfaces of the laminated film 10 were heat-sealed three times at a sealing temperature of 220 ° C., a heating time of 0.4 seconds, and a pressure of 0.2 MPa.
Using the packaging bag 1 obtained above, the contents were filled, the top seal portion 7 was sealed and sealed, and then retorted at 121 ° C. for 30 minutes.
After that. The retort-treated package obtained above was placed in a self-supporting state and heated in a 700 W household microwave oven.
As a result, the microwave packaging bag 1 according to the present invention has a bursting strength that can withstand pressure and impact applied during transportation and storage, and quickly discharges steam when cooking in a microwave oven. It was an excellent packaging bag for microwave ovens having an openability.

Next, the burst strength of the microwave packaging bag 1 obtained as described above is the microwave oven package sealed by heat sealing according to the “Burst burst strength test” in Japanese Industrial Standard JIS Z 0238. It was measured by injecting air into the bag 1 and determining the pressure at which the container bursts.
In addition, the measurement sample of the burst strength test of the container is filled with 200 g of water as the contents using the packaging bag 1 obtained above, and the top seal portion 7 is heat sealed and sealed. The retort sterilized product was used (retort sterilization conditions, temperature, 121 ° C., heating time, 30 minutes).
As a result, as shown in Table 1, the burst strength of the container of Example 1 was an average of 60 kPa.

As the bag, 12 μm thick silica-deposited polyethylene terephthalate film, 15 μm stretched nylon film, 70 μm unstretched polypropylene film are dry laminated, and from the outside, the layer structure, stretched polyethylene terephthalate film (12 μm) / silica deposited layer / A laminated film 10 of adhesive layer / stretched nylon film (15 μm) / adhesive layer / unstretched polypropylene film (70 μm) was produced.
Using the laminated film 10 obtained above, the body part is formed by heat-sealing the side edge portions of the two wall films of the front surface 2 and the rear surface 3 with the body seal part 5, and the body seal part 5 And the overhanging seal portion 9 is integrally formed. Further, after one steaming port 8 is provided in the unsealed portion 19 surrounded by the overhanging seal portion 9, the film on the bottom surface 4 is folded inside. Formed in a gusset form, the bottom seal portion 6 was heat-sealed with a boat bottom-shaped seal pattern to produce a microwave oven packaging bag 1 according to the present invention as shown in FIG. (External dimensions, height: 145 mm x width: 155 mm, vertical dimension of overhang seal part: 15 mm x horizontal dimension: 35 mm, notch diameter: 5 mm, seal width of overhang seal part: 3 mm, seal width of peripheral seal part: 10 mm (Dimension from top seal part 7 to overhanging seal part 9: 53 mm)
The unstretched polypropylene film surfaces of the laminated film 10 were heat-sealed three times at a sealing temperature of 220 ° C., a heating time of 0.4 seconds, and a pressure of 0.2 MPa.
Here, the burst strength of the microwave packaging bag 1 obtained above is the microwave oven package sealed by heat sealing in accordance with the “Burst burst strength test” in Japanese Industrial Standard JIS Z 0238. It was measured by injecting air into the bag 1 and determining the pressure at which the container bursts.
As a result, as shown in Table 1, the burst strength of the container of Example 2 was an average of 30 kPa.
Using the packaging bag 1 obtained above, the contents were filled, the top seal portion 7 was sealed and sealed, and then retorted at 121 ° C. for 30 minutes.
Thereafter, the retort-treated package obtained above was put in a self-supporting state and heated in a 700 W household microwave oven.
As a result, the microwave packaging bag 1 according to the present invention has a bursting strength that can withstand pressure and impact applied during transportation and storage, and quickly discharges steam when cooking in a microwave oven. It was an excellent packaging bag for microwave ovens having an openability.

  In addition, the measurement sample of the packaging bag 1 for the microwave oven used was filled with 200 g of water, heat sealed at the filling port, sealed, and then subjected to retort sterilization treatment (retort sterilization conditions, temperature). , 121 ° C., heating time, 30 minutes).

[Comparative Example 1]
In Example 1, the packaging bag for microwave ovens of the comparative example 1 is manufactured with the same manufacturing method using the same packaging material as Example except that the dimension from the top seal part 7 to the overhanging seal part 9 is 40 mm. Was made.
As a result, the microwave packaging bag 1 according to Comparative Example 1 has a bursting strength that can withstand pressure and impact applied during transportation and storage, but steam is quickly generated when cooking with a microwave oven. It is not discharged, the packaging bag swells more than necessary, breaks the bag, gives the consumer the fear that the contents will scatter in the microwave oven, and breaks the bag at the peripheral seal other than the overhang seal In some cases, it was not preferable.
In addition, as shown in Table 1, the burst strength of the container of Comparative Example 1 was an average of 65 kPa.

[Comparative Example 2]
In Example 1, the packaging bag for microwave ovens of the comparative example 2 of the comparative example 2 is manufactured with the same manufacturing method using the packaging material similar to an Example, except that the dimension from the top seal part 7 to the overhanging seal part 9 is 63 mm. Was made.
As a result, the microwave packaging bag 1 according to Comparative Example 2 was not preferable because it could not withstand the pressure and impact applied during transportation and storage, and could break the bag during the distribution process.
In addition, as shown in Table 1, the burst strength of the container of Comparative Example 2 was 27 kPa on average.

(Measurement result)

As a result, the packaging bag 1 of Examples 1 and 2 has a bursting strength that can withstand pressure and impact applied during transportation and storage, and can quickly discharge steam when cooking with a microwave oven. It was confirmed that the packaging bag had openness.
In contrast, the packaging bag of Comparative Example 1 has burst strength that can withstand the pressure and impact applied during transportation and storage, but steam is not quickly discharged when cooking in a microwave oven. , The packaging bag swells more than necessary, breaks the bag and gives the consumer the fear that the contents will scatter in the microwave oven, and may break the bag at the peripheral seal other than the overhang seal It was not preferable.
Further, the packaging bag of Comparative Example 2 was not preferable because it could not withstand the pressure and impact applied during transportation and storage, and the bag might break during the distribution process.

  The microwave oven packaging bag of the present invention is used for filling and packaging foods and beverages and cooking for a predetermined time in a microwave oven. For example, contents containing liquid other than solid contents are used. For example, in addition to solid foods such as frozen cucumbers, various fluid foods such as curry, soup, soy sauce, sauce, soup stock, spices, liquor for cooking, fruit juices, water, etc. There is no particular limitation as it can be filled and packaged and cooked in a microwave oven.

It is a top view which shows the Example of the packaging bag 1 for microwave ovens of this invention. It is a top view which shows the Example of another aspect of the packaging bag 1 for microwave ovens of this invention. It is sectional drawing of the laminated body 10 of the packaging material which forms the packaging bag 1 for microwave ovens of this invention. It is sectional drawing of the laminated body 10 of another aspect of the packaging material which forms the packaging bag for microwave ovens of this invention. It is a figure which shows the shape of the steaming openings 17 and 18 formed in the packaging bag for microwave ovens of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Packaging bag for microwave ovens 2 Front surface 3 Rear surface 4 Bottom surface 5 Body seal part 6 Bottom seal part 7 Top seal part 9, 16 Overhang seal part 10 Laminate 11 Base material layer 12 Adhesive layer 13 Sealant layer 14 Intermediate Layer 15 Printing layer 17 Steaming port (notch)
18 Steaming mouth (cutting)
19 Unsealed portion 20 Protruding end portion 22 Notch 23 Wing portion 24 Peripheral seal portion

Claims (4)

It is a packaging bag for heating by a microwave oven, and is formed as a peripheral seal part by heat-sealing the peripheral part with the sealant surfaces facing each other, using a laminated film having at least one side made of a sealant layer. In a packaging bag that is formed as an overhang seal portion that protrudes from the seal portion, and has a steaming port that discharges steam generated when heated in the unsealed portion and the microwave in the overhang seal portion to the outside of the bag,
A packaging bag for a microwave oven, wherein the rupture strength of the packaging bag measured according to "Containment burst strength test" in Japanese Industrial Standard JIS Z 0238 is in the range of 30 kPa to 60 kPa.   The seal strength of the peripheral seal portion and the overhang seal portion is 23 N / 15 mm or more at room temperature, and the seal strength of the overhang seal portion at 100 ° C. is 9.8 N / 15 mm or more, 23 N / 2. The microwave oven packaging bag according to claim 1, wherein the packaging bag is in a range of less than 15 mm.   The packaging bag forms a lower member having the sealant surface as an upper surface, and a wing portion in which the sealant surfaces face each other and the side portion and the tip side are sealed, and the upper member having the sealant surface as a lower surface is overlapped. In addition, the peripheral portion is sealed to form a peripheral seal portion, and the overhanging seal portion is formed in the wing portion, and the unsealed portion and the steaming port are provided in the overhanging seal portion. The packaging bag for microwave ovens in any one of Claims 1-2 characterized by these. The packaging bag is inserted into the bottom part of the front surface and the rear surface made of a quadrangle that constitutes the body part by folding the bottom surface in an inverted V shape, and heat-sealing the front surface, the rear surface, and the periphery of the bottom surface, respectively. A peripheral seal portion is formed, the overhang seal portion is formed above the packaging bag, and the self-supporting packaging bag includes the unsealed portion and the steaming opening in the overhang seal portion. The packaging bag for microwave ovens in any one of Claims 1-2 characterized by the above-mentioned.

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