JP2019131290A - bag - Google Patents

Abstract

To suppress a laminate which constitutes a bag from having damage such as a hole and a wrinkle.SOLUTION: A bag which has a storage part comprises: a laminate including a sealant film located on an inner surface of the bag and at least one plastic film positioned more on an outer surface side than the sealant film; and a seal part joining inner surfaces of the pair of laminates together. The seal part has an outer edge seal part positioned at an outer edge of the bag, and a steam release seal part positioned more on a center point side of the storage part than the outer edge seal part, and peeling off as the pressure in the storage part rises. The steam release seal part peels off when the pressure in the storage part is 130 kPa or lower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bag having a vapor vent seal portion that peels off when the internal pressure increases.

  Conventionally, many cooked or semi-cooked liquids, viscous bodies, or contents in which liquid and solid are mixed are filled and sealed in bags made of plastic laminates. In the bag, the non-seal part to which the laminated bodies are not joined constitutes an accommodation part in which the contents are accommodated. Moreover, the sealing part to which the laminated bodies are joined has sealed the accommodating part. The contents are, for example, cooked foods such as curry, stew, and soup. The contents are heated by a microwave oven or the like while being contained in a bag.

  By the way, if the contents accommodated in the sealed bag are heated using a microwave oven, the moisture contained in the contents evaporates with the heating, and the pressure in the accommodating portion increases. When the pressure in the bag storage portion increases, the bag may rupture and the contents may be scattered to contaminate the inside of the microwave oven. In consideration of such problems, for example, Patent Document 1 proposes to provide a mechanism for automatically communicating the housing portion with the outside when the pressure in the housing portion increases and releasing the vapor in the housing portion to the outside. ing. The mechanism includes a steam release seal that peels off as the pressure in the housing increases.

JP2015-120550A

  As a result of extensive research conducted by the present inventors, in the conventional bag, the pressure and temperature of the housing part when the steam release seal part peels off become excessively high, so that holes and wrinkles are formed in the laminate constituting the bag. It was found that damage such as

  An object of this invention is to provide the bag which can solve such a subject effectively.

  The present invention is a bag having a housing portion, and includes a laminate including a sealant film positioned on an inner surface of the bag and at least one plastic film positioned on an outer surface side of the sealant film, and a pair of the above A seal portion that joins the inner surfaces of the laminate, and the seal portion is located on the outer edge seal portion located on the outer edge of the bag, on the center point side of the housing portion relative to the outer edge seal portion, A steam vent seal portion that peels off due to an increase in the pressure of the housing portion, and the steam vent seal portion is a bag that peels off when the pressure of the housing portion is 130 kPa or less.

  The bag according to the present invention may be provided with a non-seal portion that is separated from the housing portion by the steam release seal portion and extends to reach an outer edge of the bag.

  In the bag according to the present invention, the tensile elongation (%) of the sealant film in the flow direction may be 800% or more, and the tensile elongation (%) of the sealant film in the vertical direction may be 1050% or more. .

  In the bag according to the present invention, the product of the tensile elongation (%) of the sealant film in the flow direction and the thickness (μm) of the sealant film is 45000 or more, and the tensile elongation (%) of the sealant film in the vertical direction. And the thickness (μm) of the sealant film may be 53,000 or more.

  In the bag according to the present invention, the sealant film may contain a propylene / ethylene block copolymer and an elastomer.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that damage, such as a hole and a wrinkle, arises in the laminated body which comprises a bag.

It is a front view which shows the bag in embodiment of this invention. It is sectional drawing which shows the case where the bag shown in FIG. 1 is seen along II-II line. It is sectional drawing which shows an example of the laminated constitution of the laminated body which comprises a bag. It is a front view which shows the bag of the state by which the upper part was sealed. It is a figure which shows an example of the method of measuring the pressure of a accommodating part. It is a front view which shows one modification of a bag. It is a front view which shows one modification of a bag. It is a figure which shows an example of the measuring method of seal strength. It is a figure which shows an example of the measuring method of seal strength. It is a figure which shows the change of the tensile stress with respect to the space | interval between a pair of grips which pulls a laminated | multilayer film in order to measure sealing strength. It is a figure which shows the evaluation result of Example A1-A14 and Comparative Example A1-A2. It is a figure which shows the other example of the method of measuring the pressure of a accommodating part. It is a figure which shows the other example of the method of measuring the pressure of a accommodating part. It is a figure which shows the other example of the method of measuring the pressure of a accommodating part. It is a figure which shows the other example of the method of measuring the pressure of a accommodating part. It is a front view which shows one modification of a bag. It is a front view which shows the bag in an Example. It is a figure which shows the evaluation result of Example B1-B3.

  An embodiment of the present invention will be described with reference to FIGS. Note that, in the drawings attached to the present specification, for convenience of illustration and understanding, the scale and vertical / horizontal dimension ratios are appropriately changed and exaggerated from those of the actual ones.

  In addition, as used in this specification, the shape and geometric conditions and the degree thereof are specified, for example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. are strictly Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  FIG. 1 is a front view showing a bag 10 according to the present embodiment. The bag 10 includes a storage portion 17 that stores the contents. In addition, in FIG. 1, the bag 10 of the state before the contents are accommodated is shown. The bag 10 by this Embodiment is comprised so that it can be conveniently used as a pouch for microwave ovens in which the contents are heated with a microwave oven.

  As shown in FIG. 1, the bag 10 according to the present embodiment includes a steam release mechanism 20 for escaping steam generated when the contents contained in the bag 10 are heated to the outside. The steam release mechanism 20 allows the inside and the outside of the bag 10 to communicate with each other when the pressure of the steam reaches a predetermined value or more to escape the steam, and suppresses the steam from being released from a place other than the steam release mechanism 20. ,It is configured. Hereinafter, the configuration of the bag 10 will be described.

In the present embodiment, the bag 10 is a gusseted bag configured to be able to stand on its own. The bag 10 includes an upper portion 11, a lower portion 12, and a pair of side portions 13, and has a substantially rectangular outline in a front view. It should be noted that names such as “upper”, “lower” and “side”, and terms such as “upper” and “lower” refer to a bag based on the state in which the bag 10 is self-supporting with the gusset portion down. It is only a relative representation of the position and direction of 10 and its components. The attitude | position at the time of transport of the bag 10 or use is not limited by the name and terminology in this specification.

  In the present embodiment, the width direction of the bag 10 is also referred to as a first direction D1. The pair of side portions 13 described above face each other in the first direction D1. A direction orthogonal to the first direction D1 is also referred to as a second direction D2. In the bag 10 of the present embodiment, a usage pattern is assumed in which, after the contents of the bag 10 are heated by a microwave oven, the bag 10 is opened by the consumer tearing the bag 10 along the first direction D1. Has been.

  As shown in FIG. 1, the bag 10 includes a surface film 14 that constitutes the front surface, a back film 15 that constitutes the back surface, and a lower film 16 that constitutes the lower portion 12. The lower film 16 is disposed between the front film 14 and the back film 15 in a state where the lower film 16 is folded at the folded portion 16f.

  In addition, the term “surface film”, “back film” and “lower film” described above is merely a partition of each film according to the positional relationship, and the method of providing a film when manufacturing the bag 10 It is not limited by the above terms. For example, the bag 10 may be manufactured using one film in which the front film 14, the back film 15, and the lower film 16 are continuously provided, or one sheet in which the front film 14 and the lower film 16 are continuously provided. It may be manufactured using a total of two films, a film and one back film 15, and a total of three films, one surface film 14, one back film 15, and one lower film 16. May be used.

  As for the surface film 14, the back film 15, and the lower film 16, inner surfaces are joined by the seal part. In the plan view of the bag 10 shown in FIG. 1 and the like, the seal portion is hatched.

  As shown in FIG. 1, the seal portion includes an outer edge seal portion extending along the outer edge of the bag 10 and a steam vent seal portion 20 a constituting the steam vent mechanism 20. The outer edge seal portion includes a lower seal portion 12 a extending in the lower portion 12 and a pair of side seal portions 13 a extending along the pair of side portions 13. In addition, in the bag 10 in a state before the contents are accommodated, as shown in FIG. 1, the upper portion 11 of the bag 10 is an opening 11b. After the contents are stored in the bag 10, the inner surface of the front film 14 and the inner surface of the back film 15 are joined at the upper portion 11, whereby an upper seal portion is formed and the bag 10 is sealed.

  The side seal portion 13a, the steam release seal portion 20a, and the upper seal portion are seal portions configured by joining the inner surface of the front film 14 and the inner surface of the back film 15. On the other hand, the lower seal portion 12a is formed by bonding the inner surface of the surface film 14 and the inner surface of the lower film 16, and by bonding the inner surface of the back film 15 and the inner surface of the lower film 16. Including a configured seal.

  As long as the opposing films can be bonded to each other and the bag 10 can be sealed, the method for forming the seal portion is not particularly limited. For example, the sealing portion may be formed by melting the inner surfaces of the film by heating or the like and welding the inner surfaces, that is, by heat sealing. Or you may form a seal | sticker part by adhere | attaching the inner surfaces of the opposing film using an adhesive agent etc.

Venting mechanism following describes the structure of venting mechanism 20. FIG. 2 is a cross-sectional view showing a case where the vapor venting mechanism 20 of the bag 10 shown in FIG. 1 is viewed along the line II-II.

  The steam release seal portion 20 a of the steam release mechanism 20 has a shape that is easily peeled off as the pressure in the housing portion 17 increases. For example, the steam release seal portion 20 a has a shape protruding from the side seal portion 13 a toward the inside of the bag 10. Thereby, when the pressure of the accommodating part 17 increases, the force added to the steam release seal part 20a can be made larger than the force applied to the side seal part 13a. Moreover, the width | variety of the steam release seal | sticker part 20a is smaller than the width | variety of the side part seal | sticker part 13a. Moreover, as shown in FIG.1 and FIG.2, the non-seal part 20b isolated from the accommodating part 17 by the steam release seal part 20a is formed between the steam release seal part 20a and the outer edge of the side part 13. Yes.

  When the contents of the bag 10 are heated, when the water contained in the contents evaporates and the pressure in the container 17 increases, the bag 10 expands around the center point C of the container 17. In this case, a force in a direction from the center point C toward the seal portion is applied to the seal portions such as the side seal portion 13a and the steam release seal portion 20a. The force applied to each position of the seal portion increases as the distance from the center point C decreases. The above-mentioned steam vent seal portion 20a protrudes from the side seal portion 13a toward the accommodating portion 17 side. Therefore, the force applied to the steam vent seal portion 20a is larger than the force applied to the side seal portion 13a. . Therefore, compared with the side seal part 13a, in the steam release seal part 20a, it is possible to easily cause communication between the housing part 17 and the outside due to peeling of the seal part.

  In the example shown in FIGS. 1 and 2, the non-seal portion 20 b of the steam release mechanism 20 extends so as to reach the side edge of the bag 10. Therefore, the part which overlaps with the non-seal part 20b among the side edges of the bag 10 is opened. In this case, the steam that has flowed into the non-seal portion 20b from the housing portion 17 through the peeling portion of the steam release seal portion 20a can smoothly escape to the outside of the bag 10 through the opening at the side edge of the bag 10. . In the following description, a bag of a type in which the non-seal portion 20b of the steam release mechanism 20 extends to the outer edge such as the side edge of the bag 10 as shown in FIGS. Also referred to as a type 1 bag.

  By the way, when the contents of the bag 10 are heated using a microwave oven or the like, a part of the contents may jump up and reach the inner surface of the laminate constituting the bag 10. When the contents attached to the inner surface of the laminate contain moisture, the contents attached to the inner surface of the laminate are further heated by the microwave oven. In this case, it is conceivable that the temperature of the laminated body in contact with the contents also rises, and holes are formed in the laminated body or wrinkles are formed in the laminated body.

  In consideration of such a problem, in the present embodiment, when the contents of the bag 10 are heated using a microwave oven or the like, the steam release seal portion is before the pressure of the storage portion 17 increases to 130 kPa. It is proposed to configure the steam release seal portion 20a so that 20a peels off. Thereby, before the temperature of the contents attached to the inner surface of the bag 10 becomes excessively high, the steam release seal part 20a is peeled off to release the steam in the storage part 17 to the outside, and the pressure of the storage part 17 and The temperature can be lowered. Thereby, it is possible to suppress the occurrence of damage such as holes and wrinkles in the laminated body of the bags 10. In the following description, the pressure of the housing portion 17 when the steam release seal portion 20a peels and the housing portion 17 communicates with the outside of the bag 10 is also referred to as a peeling pressure.

  Factors that determine the peeling pressure of the steam release seal portion 20a include the shape and size of the steam release seal portion 20a, the mechanical properties of a sealant film (described later) located on the inner surface of the laminate, and the like. In addition, when the vapor vent seal portion 20a is formed by heat seal processing, the peeling pressure of the vapor vent seal portion 20a may change depending on the heat seal processing conditions such as temperature. In the present embodiment, the peeling pressure of the steam release seal portion 20a is controlled to 130 kPa or less by appropriately adjusting these factors. The peeling pressure of the steam release seal part 20a is more preferably 120 kPa or less.

  If the peeling pressure of the vapor vent seal part 20a is too low, the vapor vent seal part 20a peels off before the contents are sufficiently heated and pressurized, and the pressure and temperature of the housing part 17 decrease. It is possible to end up. Considering this point, the peeling pressure of the steam release seal portion 20a is preferably 105 kPa or more, more preferably 110 kPa or more.

Next, the layer structure of the front film 14 and the back film 15 will be described. FIG. 3 is a cross-sectional view showing an example of the layer configuration of the laminate 30 that constitutes the front film 14 and the back film 15.

  As shown in FIG. 3, the laminate 30 includes at least a first plastic film 40, a first adhesive layer 45, a second plastic film 50, a second adhesive layer 55, and a sealant film 70 in this order. The first plastic film 40 is located on the outer surface 30y side, and the sealant film 70 is located on the inner surface 30x side opposite to the outer surface 30y. The inner surface 30x is a surface located on the accommodating portion 17 side.

  Hereinafter, each layer of the laminate 30 will be described in detail.

(First plastic film)
The first plastic film 40 is, for example, a stretched plastic film that is stretched in a predetermined direction. The first plastic film 40 functions as a base material layer for giving the laminate 30 a predetermined strength. The first plastic film 40 may be a uniaxially stretched film stretched in a predetermined direction, or may be a biaxially stretched film stretched in a predetermined two directions. The extending direction of the first plastic film 40 is not particularly limited. For example, the 1st plastic film 40 may be extended | stretched in the direction where the side part 13 is extended, and may be extended | stretched in the direction orthogonal to the direction where the side part 13 is extended. The draw ratio of the first plastic film 40 is, for example, 1.05 times or more.

  The first plastic film 40 includes, for example, polyester as a main component. For example, the first plastic film 40 includes 51% by mass or more of polyester. Examples of the polyester include polyethylene terephthalate (hereinafter also referred to as PET), polybutylene terephthalate (hereinafter also referred to as PBT), and the like. In addition, 51 mass% or more polyester in the 1st plastic film 40 may be comprised by one type of polyester, and may be comprised by two or more types of polyester.

  When the 1st plastic film 40 contains polyester as a main component, the thickness of the 1st plastic film 40 becomes like this. Preferably it is 9 micrometers or more, More preferably, it is 12 micrometers or more. Moreover, when the 1st plastic film 40 contains polyester as a main component, the thickness of the 1st plastic film 40 becomes like this. Preferably it is 25 micrometers or less, More preferably, it is 20 micrometers or less. By setting the thickness of the first plastic film 40 to 9 μm or more, the first plastic film 40 has sufficient strength. Moreover, the 1st plastic film 40 comes to show the outstanding moldability by making the thickness of the 1st plastic film 40 into 25 micrometers or less. For this reason, the process which processes the laminated body 30 and manufactures the bag 10 can be implemented efficiently.

  The first plastic film 40 may contain polyamide as a main component. For example, the first plastic film 40 includes 51% by mass or more of polyamide. Examples of polyamide systems include aliphatic polyamides or aromatic polyamides. Examples of the aliphatic polyamide include nylon-6, nylon-6,6, and nylon such as a copolymer of nylon 6 and nylon 6,6. Examples of the aromatic polyamide include polymetaxylene adipamide ( MXD6). When the first plastic film 40 includes polyamide as a main component, the puncture strength of the laminate 30 including the first plastic film 40 can be increased.

  When the 1st plastic film 40 contains a polyamide as a main component, the thickness of the 1st plastic film 40 becomes like this. Preferably it is 12 micrometers or more, More preferably, it is 15 micrometers or more. Moreover, when the 1st plastic film 40 contains a polyamide as a main component, the thickness of the 1st plastic film 40 becomes like this. Preferably it is 25 micrometers or less, More preferably, it is 20 micrometers or less.

  The 1st plastic film 40 may be comprised by the single layer, and may be comprised by the some layer. When the first plastic film 40 includes a plurality of layers, the first plastic film 40 is a co-extruded film produced by co-extrusion, for example. The first plastic film 40 produced by coextrusion is, for example, a first layer made of polyester such as PET, a second layer made of polyamide such as nylon, and a third layer made of polyester such as PET, which are sequentially laminated. including. When the mass of the second layer made of polyamide such as nylon is 51% or more of the mass of the entire first plastic film 40, the main component of the first plastic film 40 produced by co-extrusion is polyamide. I can say that.

(First adhesive layer)
The first adhesive layer 45 includes an adhesive for bonding the first plastic film 40 and the second plastic film 50 by a dry laminating method. The adhesive which comprises the 1st adhesive bond layer 45 is produced | generated from the adhesive composition produced by mixing the 1st composition containing a main ingredient and a solvent, and the 2nd composition containing a hardening | curing agent and a solvent. Specifically, an adhesive contains the hardened | cured material produced | generated by the reaction of the main ingredient and solvent in an adhesive composition.

  Examples of the adhesive include polyurethane. Polyurethane is a cured product produced by a reaction between a polyol as a main agent and an isocyanate compound as a curing agent. Examples of polyurethane include polyether polyurethane and polyester polyurethane. The polyether polyurethane is a cured product produced by a reaction between a polyether polyol as a main agent and an isocyanate compound as a curing agent. Polyester polyurethane is a cured product produced by a reaction between a polyester polyol as a main agent and an isocyanate compound as a curing agent.

  As isocyanate compounds, aromatic isocyanate compounds such as tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), etc. Aliphatic isocyanate compounds, or adducts or multimers of the above-mentioned various isocyanate compounds can be used.

  The thickness of the 1st adhesive bond layer 45 becomes like this. Preferably it is 2 micrometers or more, More preferably, it is 3 micrometers or more. Moreover, the thickness of the 1st adhesive bond layer 45 becomes like this. Preferably it is 6 micrometers or less, More preferably, it is 5 micrometers or less.

(Second plastic film)
The second plastic film 50 is, for example, a plastic film that is stretched in a predetermined direction, like the first plastic film 40. Similar to the first plastic film 40, the second plastic film 50 also functions as a base material layer for giving the laminate 30 a predetermined strength. The extending direction of the second plastic film 50 is not particularly limited as in the case of the first plastic film 40.

  Similar to the first plastic film 40, the second plastic film 50 contains polyester or polyamide as a main component. In addition, in order to give the laminated body 30 heat resistance, it is preferable that at least one of the first plastic film 40 and the second plastic film 50 contains polyester as a main component. Therefore, when the first plastic film 40 includes polyamide as a main component, the second plastic film 50 includes polyester as a main component. When the 1st plastic film 40 contains polyester as a main component, the 2nd plastic film 50 may contain polyester as a main component, and may contain polyamide as a main component.

  When the second plastic film 50 contains polyester as a main component, for example, when it contains 51% by mass or more of polyester, examples of polyester include PET, PBT, etc., as in the case of the first plastic film 40. Can do. The thickness of the second plastic film 50 is preferably 9 μm or more, and more preferably 12 μm or more. Moreover, when the 2nd plastic film 50 contains polyester as a main component, the thickness of the 2nd plastic film 50 becomes like this. Preferably it is 25 micrometers or less, More preferably, it is 20 micrometers or less. When the second plastic film 50 contains polyester as a main component, the second plastic film 50 has the same thermal conductivity, melting point, and the like as those of the first plastic film 40 containing polyester as a main component.

  When the second plastic film 50 contains polyamide as a main component, for example, when it contains 51% by mass or more of polyamide, examples of polyamide are aliphatic polyamide or aromatic polyamide as in the case of the first plastic film 40. Can be mentioned. The thickness of the 2nd plastic film 50 becomes like this. Preferably it is 12 micrometers or more, More preferably, it is 15 micrometers or more. Moreover, when the 2nd plastic film 50 contains a polyamide as a main component, the thickness of the 2nd plastic film 50 becomes like this. Preferably it is 25 micrometers or less, More preferably, it is 20 micrometers or less.

(Second adhesive layer)
The second adhesive layer 55 includes an adhesive for bonding the second plastic film 50 and the sealant film 70 by a dry laminating method. As an example of the adhesive of the second adhesive layer 55, as in the case of the first adhesive layer 45, polyurethane or the like can be used. In addition to the configuration, materials, and characteristics described below, the configuration, material, and characteristics of the second adhesive layer 55 can be the same as those of the first adhesive layer 45.

  The thickness of the second adhesive layer 55 is preferably 2 μm or more, and more preferably 3 μm or more. The thickness of the second adhesive layer 55 is preferably 6 μm or less, more preferably 5 μm or less.

  By the way, as an isocyanate compound which comprises the hardening | curing agent of an adhesive agent, as mentioned above, an aromatic isocyanate compound and an aliphatic isocyanate compound exist. Among these, aromatic isocyanate compounds elute components that cannot be used in food applications under high-temperature environments such as heat sterilization. By the way, the second adhesive layer 55 is in contact with the sealant film 70. For this reason, when the 2nd adhesive bond layer 55 contains an aromatic isocyanate compound, the component eluted from the aromatic isocyanate compound adheres to the content accommodated in the accommodating part 17 which contact | connects the sealant film 70. FIG. There is.

  In consideration of such problems, preferably, a cured product produced by a reaction between a polyol as a main agent and an aliphatic isocyanate compound as a curing agent as an adhesive constituting the second adhesive layer 55. Is used. Thereby, it can prevent that the component which cannot be used for the food use resulting from the 2nd adhesive bond layer 55 adheres to the content.

(Sealant film)
Next, the sealant film 70 will be described. As a material constituting the sealant film 70, one or more resins selected from polyethylene such as low density polyethylene and linear low density polyethylene, and polypropylene can be used. The sealant film 70 may be a single layer or a multilayer. The sealant film 70 is preferably made of an unstretched film. “Unstretched” is a concept that includes not only a film that is not stretched at all, but also a film that is slightly stretched due to the tension applied during film formation.

  A sterilization process such as a boil process or a retort process is performed at a high temperature on the bag 10 formed of the laminate 30. Therefore, the sealant film 70 having heat resistance that can withstand the processing at these high temperatures is used.

  The melting point of the material constituting the sealant film 70 is preferably 150 ° C. or higher, and more preferably 160 ° C. or higher. By increasing the melting point of the sealant film 70, the bag 10 can be retorted at a high temperature, and therefore the time required for the retort processing can be shortened. The melting point of the material constituting the sealant film 70 is lower than the melting point of the resin constituting the plastic films 40 and 50.

  When considering from the viewpoint of retort processing, a material mainly composed of propylene can be used as a material constituting the sealant film 70. Here, the material having “propylene as a main component” means a material having a propylene content of 90% by mass or more. Specific examples of the material mainly composed of propylene include propylene / ethylene block copolymer, propylene / ethylene random copolymer, polypropylene such as homopolypropylene, or a mixture of polypropylene and polyethylene. Can do. Here, the “propylene / ethylene block copolymer” means a material having a structural formula represented by the following formula (I). The “propylene / ethylene random copolymer” means a material having a structural formula represented by the following formula (II). “Homopolypropylene” means a material having the structural formula shown in the following formula (III).

  When a material containing propylene as a main component and a mixture of polypropylene and polyethylene is used, the material may have a sea-island structure. Here, the “sea-island structure” means a structure in which polyethylene is discontinuously dispersed in a region where polypropylene is continuous.

When considered from the viewpoint of boil processing, examples of the material constituting the sealant film 70 include polyethylene, polypropylene, or a combination thereof. Examples of polyethylene include medium density polyethylene, linear low density polyethylene, and combinations thereof. For example, it is also possible to use the materials mentioned as the material constituting the sealant film 70 from the viewpoint of the above retort processing. The material constituting the sealant film 70 has a melting point of, for example, 100 ° C. or higher, more preferably 105 ° C. or higher, and still more preferably 110 ° C. or higher. When polyethylene is used as the material constituting the sealant film 70, a melting point of 100 ° C. or higher can be realized, for example, when the density of polyethylene is 0.920 g / cm ³ or higher. Specific examples of the sealant film 70 having a melting point of 100 ° C. or higher include TUX-HC manufactured by Mitsui Chemicals Tosero, L6101 manufactured by Toyobo, and LS700C manufactured by Idemitsu Unitech. Specific examples of the sealant film 70 having a melting point of 105 ° C. or higher include NB-1 manufactured by Tamapoli. Specific examples of the sealant film 70 having a melting point of 110 ° C. or higher include LS760C manufactured by Idemitsu Unitech, TUX-HZ manufactured by Mitsui Chemicals Tosero, and the like.

  Preferably, the sealant film 70 is a single layer film containing a propylene / ethylene block copolymer. For example, the sealant film 70 is a single-layer unstretched film whose main component is a propylene / ethylene block copolymer. By using the propylene / ethylene block copolymer, the impact resistance of the sealant film 70 can be increased, and thereby the bag 10 can be prevented from being broken due to the impact at the time of dropping. Moreover, the puncture resistance of the laminated body 30 can be improved.

  In addition, by using a propylene / ethylene block copolymer, the strength of the seal portion constituted by the sealant film 70 at a high temperature, for example, at 100 ° C. or higher (hereinafter also referred to as “hot seal strength”) is low. For example, it becomes extremely small as compared with the seal strength at room temperature. For example, the hot seal strength at 100 ° C. is ¼ or less of the seal strength at 25 ° C. (hereinafter also referred to as room temperature seal strength). Since the hot seal strength is low, when the bag 10 is heated using a microwave oven, the steam release seal portion 20a is easily peeled off, and the steam in the housing portion 17 is easily released to the outside of the bag 10. For this reason, it can suppress that the internal pressure of the accommodating part 17 becomes excessive, and it can suppress that the laminated body 30 is damaged by this by heating. The seal strength can be measured according to JIS Z1707 7.5. As a measuring instrument, for example, a tensile tester RTC-1310A with a constant temperature bath manufactured by Orientec Co., Ltd. can be used.

  The propylene / ethylene block copolymer includes, for example, a sea component made of polypropylene and an island component made of an ethylene / propylene copolymer rubber component. The sea component can contribute to enhancing the blocking resistance, heat resistance, rigidity, seal strength and the like of the propylene / ethylene block copolymer. In addition, the island component can contribute to enhancing the impact resistance of the propylene / ethylene block copolymer. Therefore, the mechanical properties of the sealant film 70 containing the propylene / ethylene block copolymer can be adjusted by adjusting the ratio of the sea component and the island component.

  In the propylene / ethylene block copolymer, the mass ratio of the sea component made of polypropylene is higher than the mass ratio of the island component made of the ethylene / propylene copolymer rubber component. For example, in the propylene / ethylene block copolymer, the mass ratio of the sea component made of polypropylene is at least 51% by mass, preferably 60% by mass or more, and more preferably 70% by mass or more.

  The single-layer sealant film 70 may further contain a second thermoplastic resin in addition to the first thermoplastic resin made of a propylene / ethylene block copolymer. Examples of the second thermoplastic resin include an α-olefin copolymer and polyethylene. The α-olefin copolymer is, for example, linear low density polyethylene. Examples of polyethylene include low density polyethylene, medium density polyethylene, and high density polyethylene. The second thermoplastic resin can contribute to improving the impact resistance of the sealant film 70.

The low-density polyethylene, density of 0.910 g / cm ³ or more and 0.925 g / cm ³ or less of polyethylene. Medium density polyethylene is polyethylene having a density of 0.926 g / cm ³ or more and 0.940 g / cm ³ or less. The high density polyethylene is polyethylene having a density of 0.941 g / cm ³ or more and 0.965 g / cm ³ or less. Low density polyethylene is obtained, for example, by polymerizing ethylene at a high pressure of 1000 atm or more and less than 2000 atm. The medium density polyethylene and the high density polyethylene are obtained, for example, by polymerizing ethylene at a medium pressure or low pressure of 1 atm or more and less than 1000 atm.

The medium density polyethylene and the high density polyethylene may partially contain a copolymer of ethylene and α-olefin. Even when ethylene is polymerized at medium or low pressure, medium density or low density polyethylene can be produced when a copolymer of ethylene and α-olefin is included. Such polyethylene is referred to as the above-mentioned linear low density polyethylene. Linear low density polyethylene is obtained by introducing a short chain branch by copolymerizing an α-olefin with a linear polymer obtained by polymerizing ethylene at medium or low pressure. Examples of the α-olefin include 1-butene (C ₄ ), 1-hexene (C ₆ ), 4-methylpentene (C ₆ ), 1-octene (C ₈ ) and the like. The density of the linear low density polyethylene is, for example, 0.915 g / cm ³ or more and 0.945 g / cm ³ or less.

  The α-olefin copolymer constituting the second thermoplastic resin of the propylene / ethylene block copolymer is not limited to the above-mentioned linear low density polyethylene. The α-olefin copolymer means a material having a structural formula represented by the following formula (IV).

R ₁ and R ₂ are both H (hydrogen atom) or an alkyl group such as CH ₃ or C ₂ H ₅ . J and k are both integers of 1 or more. J is larger than k. That is, in the α-olefin copolymer represented by the formula (IV), the left side structure including R ₁ is the base. R ₁ is, for example, H, and R ₂ is, for example, C ₂ H ₅ .

  In the sealant film 70, the mass ratio of the first thermoplastic resin made of the propylene / ethylene block copolymer is higher than the mass ratio of the second thermoplastic resin containing at least the α-olefin copolymer or polyethylene. For example, in the single-layer sealant film 70, the mass ratio of the first thermoplastic resin made of propylene / ethylene block copolymer is at least 51% by mass, preferably 60% by mass or more, and more preferably 70% by mass or more.

  As described above, the second thermoplastic resin can contribute to enhancing the impact resistance of the sealant film 70. Therefore, the mechanical properties of the sealant film 70 can be adjusted by adjusting the mass ratio of the second thermoplastic resin containing at least the α-olefin copolymer or polyethylene in the single-layer sealant film 70.

  The sealant film 70 may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the sealant film 70 can be further enhanced.

  The thermoplastic elastomer is, for example, a hydrogenated styrene thermoplastic elastomer. The hydrogenated styrene-based thermoplastic elastomer has a structure comprising a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one hydrogenated conjugated diene compound. . The thermoplastic elastomer may be an ethylene / α-olefin elastomer. The ethylene / α-olefin elastomer is a low crystalline or amorphous copolymer elastomer, and is a random copolymer of 50 to 90% by mass of ethylene as a main component and α-olefin as a copolymerization monomer. is there.

  The content of the propylene / ethylene block copolymer in the sealant film 70 is, for example, 80% by mass or more, and preferably 90% by mass or more.

  Examples of the method for producing a propylene / ethylene block copolymer include a method of polymerizing propylene, ethylene, and the like as raw materials using a catalyst. As the catalyst, Ziegler-Natta type or metallocene catalyst can be used.

  The thickness of the sealant film 70 is preferably 30 μm or more, more preferably 40 μm or more. Moreover, the thickness of the sealant film 70 is preferably 100 μm or less, and more preferably 80 μm or less.

Hereinafter, preferable mechanical properties of the single-layer sealant film 70 containing a propylene / ethylene block copolymer will be described.
The tensile elongation at 25 ° C. of the sealant film 70 in the flow direction (MD) is preferably 600% or more and 1300% or less. The product of the tensile elongation (%) of the sealant film 70 and the thickness (μm) of the sealant film 70 in the flow direction (MD) is preferably 35000 or more and 80000 or less. Further, the tensile elongation at 25 ° C. of the sealant film 70 in the vertical direction (TD) is preferably 700% or more and 1400% or less. The product of the tensile elongation (%) of the sealant film 70 in the vertical direction (TD) and the thickness (μm) of the sealant film 70 is preferably 40000 or more and 85000 or less.
The tensile modulus at 25 ° C. of the sealant film 70 in the flow direction (MD) is preferably 400 MPa or more and 1100 MPa or less. Moreover, the product of the tensile modulus (MPa) of the sealant film 70 and the thickness (μm) of the sealant film 70 in the flow direction (MD) is preferably 30000 or more and 55000 or less. Further, the tensile elastic modulus at 25 ° C. of the sealant film 70 in the vertical direction (TD) is preferably 250 MPa or more and 900 MPa or less. The product of the tensile elastic modulus (MPa) of the sealant film 70 and the thickness (μm) of the sealant film 70 in the vertical direction (TD) is preferably 20000 or more and 45000 or more.

  The tensile modulus and tensile elongation can be measured according to JIS K7127. As a measuring device, a tensile tester RTC-1310A with a constant temperature bath manufactured by Orientec Co., Ltd. can be used. In the bag 10 shown in FIG. 1, the direction in which the upper part 11 and the lower part 12 extend is the flow direction of the sealant film 70, and the direction in which the side part 13 extends is the vertical direction of the sealant film 70. Although not shown, the bag 10 may be configured such that the direction in which the upper part 11 and the lower part 12 extend is the vertical direction of the sealant film 70 and the direction in which the side part 13 extends is the flow direction of the sealant film 70. .

There are mainly two types of the single-layer sealant film 70 containing a propylene / ethylene block copolymer.
The first is a type having high tensile elongation and impact resistance, such as ZK500 described later. The first type sealant film 70 preferably further has a characteristic that the hot seal strength is low. Thereby, it can suppress that the internal pressure of the accommodating part 17 becomes excessive at the time of the heating of the bag 10, and it can suppress that the laminated body 30 arises a damage.
The second is a type having a high tensile elastic modulus, such as ZK207 described later. By using the second type sealant film 70, it is possible to improve the tearability when the bag 10 is opened by the consumer tearing the bag 10 along the first direction D1.

The product of the tensile elongation (%) of the first type sealant film 70 in the flow direction (MD) and the thickness (μm) of the sealant film 70 is preferably 45000 or more, more preferably 50000 or more, and 55000. Or more, or 60000 or more. The product of the tensile elongation (%) of the first type sealant film 70 in the vertical direction (TD) and the thickness (μm) of the sealant film 70 is preferably 53,000 or more, more preferably 60000 or more. . Since the sealant film 70 has a high tensile elongation, the bag 10 can be prevented from being broken due to an impact at the time of dropping or the like.
Further, the product of the tensile modulus (MPa) of the first type sealant film 70 and the thickness (μm) of the sealant film 70 in the flow direction (MD) is preferably 38000 or less, more preferably 35000 or less. . Further, the product of the tensile modulus (MPa) of the first type sealant film 70 and the thickness (μm) of the sealant film 70 in the vertical direction (TD) is preferably 30000 or less, more preferably 25000 or less. .

The product of the tensile elastic modulus (MPa) of the second type sealant film 70 and the thickness (μm) of the sealant film 70 in the flow direction (MD) is preferably 35000 or more, more preferably 38000 or more, Preferably it is 45000 or more. The product of the tensile modulus (MPa) of the second type sealant film 70 and the thickness (μm) of the sealant film 70 in the vertical direction (TD) is preferably 25000 or more, more preferably 30000 or more. More preferably, it is 35000 or more, and may be 38000 or more. When the sealant film 70 has a high tensile elastic modulus, the tearability when the bag 10 is opened can be improved.
The product of the tensile elongation (%) of the second type sealant film 70 and the thickness (μm) of the sealant film 70 in the flow direction (MD) is preferably 55000 or less, more preferably 50000 or less. . The product of the tensile elongation (%) of the second type sealant film 70 and the thickness (μm) of the sealant film 70 in the vertical direction (TD) is preferably 60000 or less, more preferably 55000 or less. .

(Other layers)
The laminate 30 may further include a layer not shown in FIG. In the following, examples of further layers are described.

  The laminate 30 may further include a printing layer. The printed layer is a layer provided on the laminated body 30 in order to show product information or give aesthetics to the bag 10, and is printed on the first plastic film 40, for example. The print layer expresses letters, numbers, symbols, figures, patterns, and the like. As a material constituting the printing layer, gravure printing ink or flexographic printing ink can be used. As a specific example of the ink for gravure printing, FINAT manufactured by DIC Graphics Corporation can be given.

  Moreover, the laminated body 30 may further include a transparent gas barrier layer. The transparent gas barrier layer is formed on the surface of the plastic films 40 and 50 and includes at least a transparent vapor deposition layer made of an inorganic material having transparency. The transparent gas barrier layer may further include a transparent gas barrier coating film formed on the surface of the transparent vapor deposition layer and having transparency.

  The transparent vapor deposition layer functions as a layer having a gas barrier function that prevents permeation of oxygen gas and water vapor. Two or more transparent vapor deposition layers may be provided. When it has two or more transparent vapor deposition layers, each may have the same composition or different compositions. As a method for forming a transparent vapor deposition layer, for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, a plasma chemical vapor deposition method, a heat Examples include chemical vapor deposition and chemical vapor deposition (chemical vapor deposition, CVD) such as photochemical vapor deposition. Specifically, a vapor deposition layer can be formed on a film formation roller using a roller-type vapor deposition film forming apparatus. Examples of the inorganic material constituting the transparent vapor deposition layer include aluminum oxide (aluminum oxide) and silicon oxide. The thickness of the transparent vapor deposition layer is preferably 40 mm or more and 130 mm or less, more preferably 50 mm or more and 120 mm or less.

The transparent gas barrier coating film is a layer that functions as a layer that suppresses permeation of oxygen gas, water vapor, and the like. The transparent gas barrier coating film has a general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer greater than or equal to 0, m represents an integer greater than or equal to 1, n + m represents the valence of M), and the polyvinyl alcohol as described above. Obtained by a transparent gas barrier composition containing a polyoxyethylene resin and / or an ethylene / vinyl alcohol copolymer and further polycondensed by a sol-gel method in the presence of a sol-gel method catalyst, an acid, water, and an organic solvent. It is done.

Next, the layer structure of the lower film 16 will be described.

  As long as it has the inner surface which can be joined with the inner surface of the surface film 14 and the inner surface of the back surface film 15, the layer structure of the lower film 16 is arbitrary. For example, similar to the front film 14 and the back film 15, the above-described laminate 30 may be used as the lower film 16. Alternatively, a film having an inner surface constituted by a sealant layer and a configuration different from that of the laminate 30 may be used as the lower film 16.

Method for producing a laminate Next, an example of a method for producing a laminate 30.

  First, the first plastic film 40 and the second plastic film 50 described above are prepared. Subsequently, the first plastic film 40 and the second plastic film 50 are laminated via the first adhesive layer 45 by a dry laminating method. Thereafter, the laminate including the first plastic film 40 and the second plastic film 50 and the sealant film 70 are laminated via the second adhesive layer 55 by a dry laminating method. Thereby, the laminated body 30 provided with the 1st plastic film 40, the 2nd plastic film 50, and the sealant film 70 can be obtained.

  Alternatively, the second plastic film 50 and the sealant film 70 are first laminated by the dry laminating method through the second adhesive layer 55, and then the first plastic film 40, the second plastic film 50, and the sealant film 70 are included. The laminate 30 may be manufactured by laminating the laminate with the first adhesive layer 45 by a dry laminating method.

  In the dry laminating method, first, an adhesive composition is applied to one of two laminated films. Subsequently, the applied adhesive composition is dried to volatilize the solvent. Then, two films are laminated | stacked through the adhesive composition after drying. Subsequently, aging is performed for 24 hours or more in an environment of 20 ° C. or higher, for example, in a state where the two laminated films are wound up.

Method for producing a bag Next, a method for producing the bag 10 with the laminate 30 described above. First, the surface film 14 and the back film 15 which consist of the laminated body 30 are prepared. In addition, the lower film 16 in a folded state is inserted between the front film 14 and the back film 15. Subsequently, the inner surfaces of the films are heat-sealed to form seal portions such as the lower seal portion 12a, the side seal portion 13a, and the steam release seal portion 20a. Further, the films bonded to each other by heat sealing are cut into an appropriate shape to obtain a bag 10 shown in FIG. Subsequently, the contents 18 are filled into the bag 10 through the opening 11 b of the upper portion 11. The contents 18 are cooked foods containing moisture, such as curry, stew, and soup. The contents 18 may have a material containing a large amount of oil, such as meat and fish and seasonings for them. In addition to food, items that can be heated by hot water can be stored in the bag 10 as contents. Thereafter, the upper part 11 is heat-sealed to form an upper seal part. Thus, as shown in FIG. 4, the bag 10 in which the contents 18 are accommodated and sealed can be obtained. Thereafter, a sterilization process such as a boil process or a retort process is performed on the bag 10 containing the contents 18 as necessary.

  In FIG. 4, symbol H <b> 1 represents the distance in the second direction D <b> 2 from the upper seal portion 11 a to the center point C of the housing portion 17. Further, the symbol H2 represents the shortest distance from the steam release seal portion 20a to the center point C of the housing portion 17. In the type 1 bag as shown in FIG. 4, the ratio of the distance H1 to the distance H2 (= H1 / H2) is, for example, 1.05 or more and 4.0 or less, more preferably 1.1 or more and 4. 0 or less. By setting the distance H1 and the distance H2 in this way, it is possible to prevent the upper seal portion 11a from being peeled before the vapor vent seal portion 20a when the bag 10 is heated. The center point C of the accommodating portion 17 is defined as the midpoint of a line segment connecting the midpoint Y1 of the inner edge of the upper seal portion 11a and the midpoint Y2 of the inner edge of the lower seal portion 12a.

  When the seal part such as the steam release seal part 20a is formed by the heat seal process, the conditions of the heat seal process are set according to the material of the sealant film 70 so that the peeling pressure of the steam release seal part 20a is 130 kPa or less. The

Next, a method for measuring the peeling pressure of the steam release seal portion 20a will be described. First, as shown in FIG. 1, the method for measuring the peeling pressure of the steam release seal portion 20a when the bag 10 in the state where the upper seal portion 11a is not formed on the upper portion 11 is available is shown in FIG. The description will be given with reference. FIG. 5 is a longitudinal sectional view showing the bag 10 in which the sensor 81 for measuring the peeling pressure is provided in the housing portion 17.

  First, as shown in FIG. 1 described above, a bag 10 is prepared in a state where the upper seal portion 11a is not formed on the upper portion 11 and the upper portion 11 is an opening portion 11b. Subsequently, a data logger sensor 81 capable of measuring pressure is provided inside the bag 10. For example, the sensor 81 is attached to the inner surface of the bag 10. Further, a predetermined amount of water, for example, 100 ml of water is filled in the storage portion 17 of the bag 10. Thereafter, a seal portion is formed in the opening of the bag 10 to seal the bag 10. As the data logger, for example, PICAVACQ PT made by TMI-ORION can be used. PicoVACQ PT can also measure temperature in addition to pressure.

  Subsequently, the water in the bag 10 is heated using a microwave oven or the like while measuring the pressure of the housing portion 17 at predetermined time intervals using the sensor 81. As a microwave oven, the arbitrary things in the range whose output is 500W-1500W can be used. The time interval is, for example, not less than 0.1 seconds and not more than 10 seconds, for example, 1.0 seconds.

  When water evaporates and the pressure in the accommodating portion 17 increases, the steam release seal portion 20a begins to peel off. When the peeling of the steam release seal portion 20a proceeds to the outer edge of the bag 10 and the accommodating portion 17 communicates with the non-sealed portion 20b and the outside of the bag 10, the pressure of the accommodating portion 17 measured by the sensor 81 rapidly decreases. To do. The pressure of the storage part 17 measured immediately before the pressure starts to drop rapidly is recorded as the peeling pressure of the steam release seal part 20a. The temperature of the housing part 17 immediately before the pressure starts to drop rapidly is, for example, 80 ° C. or more and 120 ° C. or less.

  Next, a method for measuring the peeling pressure of the steam release seal portion 20a using the bag 10 in which the contents are accommodated and the upper portion 11 is sealed as shown in FIG. 4 will be described with reference to FIGS. 12A to 12D. Will be described with reference to FIG.

  First, the bag 10 with a part opened is prepared. Specifically, first, as shown in FIG. 4, a bag 10 is prepared in a state in which the contents are accommodated and the upper portion 11 is sealed. Subsequently, an opening for taking out the contents is provided in either the front film 14 or the back film 15. For example, as shown in FIG. 12A, an opening 14 c is provided in the surface film 14 by forming a cut through the surface film 14 in the surface film 14. The opening part 14c is located below the upper seal part 11a and above the steam release seal part 20a. Further, the opening 14c extends in the first direction D1 so as not to reach either the one side seal part 13a or the other side seal part 13a. Thereafter, the contents stored in the bag 10 are taken out through the opening 14c. Thereafter, the inside of the bag 10 may be washed to further remove the contents attached to the inner surface of the bag 10.

  Then, the film 14d which can be heat-welded to the inner surface 30x of the surface film 14 provided with the opening part 14c is prepared. The film 14d can be introduced into the accommodating portion 17 of the bag 10 through the opening 14c, and has a shape that can cover the opening 14c. As the film 14d, the same laminate as the surface film 14 can be used. Such a film 14d can be prepared by, for example, purchasing the bag 10 and cutting out the surface film 14 of the bag 10 when the bag 10 is commercially available with the contents contained therein.

  Subsequently, as shown in FIG. 12B, the film 14d is introduced into the accommodating portion 17 of the bag 10 through the opening 14c. At this time, the inner surface of the film 14 d is set to face the inner surface 30 x side of the surface film 14. The film 14d is located between the inner edge 11c of the upper seal part 11a of the bag 10 and the upper edge 20d of the steam release seal part 20a in the second direction D2. The film 14d is positioned between the inner edge 13d of one side seal portion 13a and the inner edge 13d of the other side seal portion 13a. The film 14d covers the entire area of the opening 14c. Thereafter, the inner surface of a portion of the film 14d located above the opening 14c is thermally welded to the inner surface 30x of the surface film 14. In FIG. 12B, the seal part 14e formed by heat welding is hatched.

  Next, as shown in FIG. 12C, a data logger sensor 81 capable of measuring pressure is introduced into the bag 10 through the opening 14c. For example, the sensor 81 is attached to the inner surface of the bag 10. In addition, a predetermined amount of water, for example, 100 ml of water, for example, is filled into the accommodating portion 17 of the bag 10 through the opening 14c. Thereafter, the inner surface of the film 14d is thermally welded to the inner surface 30x of the surface film 14 so as to seal the bag 10 from the outside. For example, a portion of the inner surface of the film 14d that has not yet been thermally welded to the inner surface 30x of the surface film 14 is heated and pressed. Thereby, as shown to FIG. 12D, the opening part 14c of the bag 10 can be sealed. After that, as described above, the peeling pressure is measured by heating the water in the bag 10 using a microwave oven or the like while measuring the pressure of the housing portion 17 at a predetermined time interval using the sensor 81. be able to.

Heating method of the contents Next, an example of a method for heating the contents 18 contained in the bag 10.

  First, the bag 10 is placed inside the microwave oven in a state where the bag 10 is self-supporting with the lower portion 12 facing down. Next, the contents are heated using a microwave oven. As a result, the temperature of the contents 18 increases, and accordingly, the water contained in the contents 18 evaporates and the pressure in the accommodating portion 17 increases.

  When the pressure in the housing part 17 increases, the surface film 14 and the back film 15 bulge outward by the force received from the housing part 17. Here, in the present embodiment, the steam release mechanism 20 is configured so that the peeling pressure of the steam release seal portion 20a is 130 kPa or less. For this reason, before the pressure of the accommodating part 17 increases to 130 kPa, the steam release seal part 20a peels off. Accordingly, it is possible to suppress the formation of a hole in the laminated body 30 of the bag 10 or the formation of wrinkles in the laminated body 30 during heating.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modification, the description thereof may be omitted.

(First variation of bag)
In the steam venting mechanism 20 of the above-described embodiment, an example in which the non-seal portion 20b separated from the housing portion 17 by the steam vent seal portion 20a spreads to reach the outer edge of the bag 10 has been shown. However, the present invention is not limited to this, and as shown in FIG. 6, the non-seal portion 20b may be surrounded by the steam release seal portion 20a and the side seal portion 13a. In this case, a through-hole 20c that penetrates at least one of the front film 14 or the back film 15 is formed in the non-seal portion 20b. In this case, the steam that has flowed into the non-seal portion 20b from the housing portion 17 through the peeled portion of the steam release seal portion 20a passes through the through hole 20c and escapes to the outside of the bag 10. In the following description, a bag of the type in which the non-seal portion 20b of the steam release mechanism 20 is surrounded by the steam release seal portion 20a and one side seal portion 13a as shown in FIG. Also referred to as a type 2 bag.

  In the bag 10 shown in FIG. 6, the non-seal part 20b is located in the accommodating part 17 side rather than the side part seal part 13a. For this reason, when the width of the non-seal portion 20b in the first direction D1 is the same, the distance H2 from the steam release seal portion 20a of the bag 10 of type 2 of this modification to the center point C is as shown in FIGS. The distance H2 from the steam release seal portion 20a of the type 1 bag 10 to the center point C is shorter than the distance H2. For this reason, when the contents of the bag 10 are heated using a microwave oven or the like, a force is easily applied to the vapor vent seal portion 20a, and the peeling pressure of the vapor vent seal portion 20a tends to be low. In the type 2 bag as shown in FIG. 6, the ratio of the distance H1 to the distance H2 (= H1 / H2) is, for example, not less than 1.05 and not more than 5.0.

  Also in this modification, the steam release mechanism 20 is configured such that the peeling pressure of the steam release seal portion 20a is 130 kPa or less. For this reason, before the pressure of the accommodating part 17 increases to 130 kPa, the steam release seal part 20a peels off. Accordingly, it is possible to suppress the formation of a hole in the laminated body 30 of the bag 10 or the formation of wrinkles in the laminated body 30 during heating.

(Second modification of bag)
In the steam venting mechanism 20 of the present embodiment and the first modification described above, the steam vent seal portion 20a is connected to one side seal portion 13a. However, the present invention is not limited to this, and as shown in FIG. 7, the steam release seal portion 20a may be separated from the side seal portion 13a. In this case, a through-hole 20c penetrating at least one of the front film 14 or the back film 15 is formed in the non-seal part 20b surrounded by the steam release seal part 20a. Similarly to the case of the first modification, the steam that has flowed into the non-seal portion 20b from the housing portion 17 through the peeled portion of the steam release seal portion 20a passes through the through hole 20c and escapes to the outside of the bag 10. In the following description, the type of bag in which the steam release seal portion 20a of the steam release mechanism 20 is spaced from the side seal portion 13a as shown in FIG. 7 is also referred to as a type 3 bag.

  In the bag 10 shown in FIG. 6, the non-seal part 20b is spaced apart from the side seal part 13a. For this reason, when the width of the non-seal portion 20b in the first direction D1 is the same, the distance H2 from the steam release seal portion 20a of the bag 10 of type 3 of this modification to the center point C is the type shown in FIG. It is shorter than the distance H2 from the steam release seal portion 20a of the second bag 10 to the center point C. For this reason, when the contents of the bag 10 are heated using a microwave oven or the like, a force is more likely to be applied to the steam release seal portion 20a, and the peeling pressure of the steam release seal portion 20a is likely to be lower. In the type 3 bag as shown in FIG. 7, the ratio of the distance H1 to the distance H2 (= H1 / H2) is, for example, not less than 1.05 and not more than 6.0.

  Also in this modification, the steam release mechanism 20 is configured such that the peeling pressure of the steam release seal portion 20a is 130 kPa or less. For this reason, before the pressure of the accommodating part 17 increases to 130 kPa, the steam release seal part 20a peels off. Accordingly, it is possible to suppress the formation of a hole in the laminated body 30 of the bag 10 or the formation of wrinkles in the laminated body 30 during heating.

  Note that when the distance H2 from the steam vent seal portion 20a to the center point C is shortened, a force is easily applied to the steam vent seal portion 20a other than when the contents of the bag 10 are heated using a microwave oven or the like. For example, when transporting the bag 10 in a state where a plurality of bags 10 are stacked, a force is easily applied to the steam release seal portion 20a, and unintentional release of the steam release seal portion 20a is likely to occur. In other words, the shorter the distance H2 from the steam release seal portion 20a to the center point C, the lower the load resistance of the bag 10. Therefore, in view of the load resistance of the bag 10, the type 2 bag 10 is preferable to the type 3 bag 10, and the type 1 bag 10 is more preferable.

(Third modification of bag)
In the above-described embodiment, an example in which the bag 10 is a gusset type pouch including the front film 14, the back film 15, and the lower film 16 has been described. However, the present invention is not limited to this, and as shown in FIG. 13, the bag 10 may be a so-called flat pouch provided with a front film 14 and a back film 15. In this case, the bag 10 is heated by the microwave oven in a state where the posture of the bag 10 is maintained such that the steam release seal portion 20a is positioned above the center point C of the housing portion 17 in the vertical direction. For example, when the bag 10 is sold in a state of being accommodated in a paper box (not shown), the bag 10 can be maintained in a predetermined posture using the box.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded. Here, the sealing strength of the laminated body 30 constituting the bag 10 and the peeling pressure of the vapor vent seal portion 20a of the bag 10 were evaluated.

(Example A1)
A stretched PET film having a thickness of 12 μm was prepared as the first plastic film 40. In addition, a stretched nylon film having a thickness of 15 μm was prepared as the second plastic film 50. Further, as the sealant film 70, an unstretched polypropylene film ZK500 manufactured by Toray Film Processing Co., Ltd. was prepared. ZK500 contains the above-mentioned propylene / ethylene block copolymer and elastomer. The thickness of the sealant film 70 was 60 μm.

  ZK500 has a higher tensile elongation than a general unstretched polypropylene film. Specifically, the tensile elongation of ZK500 in the flow direction (MD) is 1180% when the thickness is 50 μm and 1100% when the thickness is 60 μm. The tensile elongation of ZK500 in the vertical direction (TD) is 1240% when the thickness is 50 μm, and 1150% when the thickness is 60 μm. Therefore, the product of the tensile elongation (%) and the thickness (μm) of ZK500 in the flow direction is 59000 when the thickness is 50 μm and 66000 when the thickness is 60 μm. The product of the tensile elongation (%) and thickness (μm) of ZK500 in the vertical direction is 62000 when the thickness is 50 μm and 69000 when the thickness is 60 μm.

  ZK500 has a lower tensile elastic modulus than a general unstretched polypropylene film. Specifically, the tensile modulus of elasticity of ZK500 in the flow direction (MD) is 640 MPa when the thickness is 50 μm, and 550 MPa when the thickness is 60 μm. The tensile modulus of elasticity of ZK500 in the vertical direction (TD) is 480 MPa when the thickness is 50 μm, and 400 MPa when the thickness is 60 μm. Therefore, the product of the tensile modulus (MPa) and the thickness (μm) of ZK500 in the flow direction is 32000 when the thickness is 50 μm and 33000 when the thickness is 60 μm. The product of the tensile modulus (MPa) and thickness (μm) of ZK500 in the vertical direction is 24000 when the thickness is 50 μm and 35000 when the thickness is 60 μm.

  Then, the 1st plastic film 40, the 2nd plastic film 50, and the sealant film 70 were laminated | stacked by the dry lamination method, and the laminated body 30 was produced. As the first adhesive layer 45 and the second adhesive layer 55, a two-component polyurethane adhesive (main agent: RU-40, curing agent: H-4) manufactured by Rock Paint Co., Ltd. was used. In addition, RU-40 of the main ingredient is a polyester polyol. The thickness of the 1st adhesive bond layer 45 and the 2nd adhesive bond layer 55 was 3.5 micrometers.

(Evaluation of seal strength)
Subsequently, the inner surfaces 30x of the two laminates 30 were partially heat-sealed at 210 ° C. Then, the sealing strength between the laminated bodies 30 was measured based on JIS17077.5 in 23 degreeC atmosphere. As a measuring device, a tensile tester RTC-1310A with a constant temperature bath manufactured by Orientec Co., Ltd. was used. Specifically, first, two heat-sealed laminates 30 were cut out to produce a rectangular test piece 90 having a width (short side) of 15 mm. In the test piece 90, as shown in FIG. 8, the two laminated bodies 30 are peeled over 15 mm from one end in the long side direction. Thereafter, as shown in FIG. 9, the already peeled portions of the two laminates 30 were each gripped by the gripping tool 91 and the gripping tool 92 of the measuring instrument. In addition, each of the grips 91 and 92 is pulled at a speed of 300 mm / min in directions opposite to each other in the direction orthogonal to the surface direction of the portion where the two laminated bodies 30 are still joined, The value (see FIG. 10) was measured. FIG. 10 is a diagram showing changes in tensile stress with respect to the spacing S. FIG.
For the five test pieces 90, the maximum value of the tensile stress was measured, and the average value was taken as the seal strength of the laminate 30. The distance S between the grips 91 and 92 when starting the tension was 20 mm, and the distance S between the grips 91 and 92 when finishing the tension was 40 mm. The environment during the measurement was a temperature of 23 ° C. and a relative humidity of 50%. As a result, the seal strength at 15 mm width (hereinafter also referred to as room temperature seal strength) was 65N.

  In addition, you may measure sealing strength using the test piece 90 obtained by cutting out the part containing the one side part seal part 13a among the surface film 14 and the back surface film 15 of the bag 10. FIG.

(Evaluation of peeling pressure)
Then, the bag 10 provided with the type 1 steam release mechanism 20 shown in FIG.1 and FIG.4 using the laminated body 30 was produced. In the produced bag 10, the upper part 11 is not formed with an upper seal part 11a, and the upper part 11 is an opening part 11b. The height S1 of the bag 10 was 145 mm, and the width S2 was 140 mm. Further, the height S3 of the folded lower film 16, that is, the height from the lower end portion of the bag 10 to the folded portion 16f was 40 mm. In the following description, the bag 10 having a height S1 of 145 mm, a width S2 of 140 mm, and a height S3 of 40 mm is also referred to as an S-size bag 10. Subsequently, 100 ml of water was filled into the bag 10, and a data logger sensor 81 was placed inside the bag 10, and the upper portion 11 of the bag 10 was heat sealed to form an upper seal portion 11 a. The distance H1 in the second direction D2 from the upper seal portion 11a to the center point C of the housing portion 17 was 67 mm. Moreover, the shortest distance H2 from the steam release seal part 20a to the center point C of the accommodating part 17 was 60 mm. In this case, the ratio of the distance H1 to the distance H2 (= H1 / H2) is 1.12.

  Then, the water in the bag 10 was heated using the microwave oven of output 500W, measuring the pressure of the accommodating part 17 every second using the sensor 81. FIG. As a microwave oven with an output of 500 W, NE-MS261 manufactured by Panasonic was used. When the pressure of the storage part 17 increases and the peeling of the steam release seal part 20a reaches the outer edge of the bag 10, the steam in the storage part 17 begins to be discharged to the outside of the bag 10, and the pressure of the storage part 17 rapidly decreases. . The peeling pressure, which is the pressure in the housing portion 17 immediately before the pressure starts to drop rapidly, was 116.1 kPa. In addition, the temperature (hereinafter also referred to as the reached temperature) reached by the accommodating portion 17 immediately before the pressure began to drop rapidly was 102 ° C. Further, the time from the start of heating to the time when the pressure began to drop rapidly (hereinafter also referred to as the required time) was 145 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A2)
Type 1 bag 10 was produced using the same laminate 30 as in Example A1. The height S1 of the bag 10 was 145 mm, the width S2 was 150 mm, and the height S3 of the folded lower film 16 was 43 mm. In the following description, the bag 10 having a height S1 of 145 mm, a width S2 of 150 mm, and a height S3 of 43 mm is also referred to as an M size bag 10. Subsequently, as in Example A1, 100 ml of water was filled into the bag 10, and the upper part 11 was heat-sealed to form an upper seal part. The temperature of the heat seal process was 210 ° C. as in Example A1. In this case, the normal temperature sealing temperature is 65 N as in the case of Example A1. The distance H1 in the second direction D2 from the upper seal portion 11a to the center point C of the housing portion 17 was 68 mm. Further, the shortest distance H2 from the steam release seal portion 20a to the center point C of the accommodating portion 17 was 65 mm. In this case, the ratio of the distance H1 to the distance H2 (= H1 / H2) is 1.04.

  Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 113.5 kPa, the ultimate temperature was 100 ° C., and the required time was 131 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A3)
The seal strength between the laminates 30 was measured using a test piece 90 prepared by heat-sealing the same laminate 30 as in Example A1 at 200 ° C. As a result, the normal temperature seal strength was 55N.

  Further, an S size type 1 bag 10 was produced in the same manner as in Example A1 except that the temperature of the heat sealing treatment was 200 ° C. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 110 kPa, the reached temperature was 102 ° C., and the required time was 160 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A4)
An M size type 1 bag 10 was produced in the same manner as in Example A2, except that the temperature of the heat sealing treatment was set to 200 ° C. as in Example A3. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 110.5 kPa, the ultimate temperature was 102 ° C., and the required time was 163 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30. Note that the normal temperature sealing temperature in this example is 55 N, as in Example A3.

(Example A5)
The same laminate 30 as in Example A3 was heat-sealed at 200 ° C. to produce an S-sized type 1 bag 10 similar to that in Example A3. Subsequently, the water in the bag 10 was heated using a microwave oven with an output of 1600 W while measuring the pressure in the container 17 using the sensor 81. A NE-1801 manufactured by Panasonic was used as the microwave oven with an output of 1600 W. The peeling pressure was 117 kPa, the reached temperature was 98.9 ° C., and the required time was 52 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A6)
The same laminate 30 as in Example A4 was heat-sealed at 200 ° C. to produce an M size type 1 bag 10 similar to that in Example A4. Subsequently, while measuring the pressure in the container 17 using the sensor 81, the water in the bag 10 was heated using a microwave oven with an output of 1600 W, as in Example A5. The peeling pressure was 117.9 kPa, the ultimate temperature was 99.7, and the required time was 54 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A7)
A stretched PET film having a thickness of 12 μm was prepared as the first plastic film 40. In addition, a stretched PET film having a thickness of 12 μm was prepared as the second plastic film 50. Further, as the sealant film 70, an unstretched polypropylene film ZK500 manufactured by Toray Film Processing Co., Ltd. was prepared. The thickness of the sealant film 70 was 60 μm.

  Subsequently, using the test piece 90 produced by partially heat-sealing the inner surfaces 30x of the two laminates 30 at 200 ° C., the seal between the laminates 30 is performed in the same manner as in Example A1. The strength was measured. As a result, the normal temperature seal strength was 55N.

  In addition, an S size type 1 bag 10 was produced in the same manner as in Example A1. The temperature of the heat seal process was 200 ° C. Thereafter, as in Example A5, the water in the bag 10 was heated using a microwave oven with an output of 1600 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 114.8 kPa, the reached temperature was 102 ° C., and the required time was 63 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Comparative Example A1)
A stretched PET film having a thickness of 12 μm was prepared as the first plastic film 40. In addition, a stretched PET film having a thickness of 12 μm was prepared as the second plastic film 50. Further, as the sealant film 70, an unstretched polypropylene film ZK207 manufactured by Toray Film Processing Co., Ltd. was prepared. The thickness of the sealant film 70 was 70 μm.

  ZK207 has a lower tensile elongation than ZK500. Specifically, the tensile elongation of ZK207 in the flow direction (MD) is 790% when the thickness is 50 μm and 730% when the thickness is 60 μm. The tensile elongation of ZK207 in the vertical direction (TD) is 1020% when the thickness is 50 μm, and 870% when the thickness is 60 μm. Therefore, the product of the tensile elongation (%) and thickness (μm) of ZK207 in the flow direction is 39500 when the thickness is 50 μm and 43800 when the thickness is 60 μm. The product of the tensile elongation (%) and the thickness (μm) of ZK207 in the vertical direction is 51000 when the thickness is 50 μm and 52200 when the thickness is 60 μm.

  Further, ZK207 has a higher tensile elastic modulus than ZK500. Specifically, the tensile modulus of elasticity of ZK207 in the flow direction (MD) is 780 MPa when the thickness is 50 μm and 680 MPa when the thickness is 60 μm. Further, the tensile modulus of elasticity of ZK207 in the vertical direction (TD) is 630 MPa when the thickness is 50 μm and 560 MPa when the thickness is 60 μm. Therefore, the product of the tensile modulus (MPa) and the thickness (μm) of ZK207 in the flow direction is 39000 when the thickness is 50 μm and 40800 when the thickness is 60 μm. The product of the tensile modulus (MPa) and thickness (μm) of ZK207 in the vertical direction is 31500 when the thickness is 50 μm and 33600 when the thickness is 60 μm.

  Subsequently, using the test piece 90 produced by partially heat-sealing the inner surfaces 30x of the two laminates 30 at 210 ° C., the seal between the laminates 30 is performed in the same manner as in Example A1. The strength was measured. As a result, the normal temperature seal strength was 65N.

  In addition, an S size type 1 bag 10 was produced in the same manner as in Example A1. The temperature of the heat sealing process was 210 ° C. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 130.7 kPa, the ultimate temperature was 101 ° C., and the required time was 147 seconds. Further, in the heated bag 10, holes and wrinkles were formed in the laminate 30.

(Comparative Example A2)
Using the same laminate 30 as in Comparative Example A1, an M size type 1 bag 10 was produced. The temperature of the heat sealing process was 210 ° C. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 132.5 kPa, the ultimate temperature was 102 ° C., and the required time was 125 seconds. Further, in the heated bag 10, holes and wrinkles were formed in the laminate 30.

(Example A8)
The seal strength between the laminates 30 was measured using a test piece 90 produced by heat-sealing the same laminate 30 as in Comparative Example A1 at 200 ° C. As a result, the normal temperature seal strength was 55N.

  Further, an S size type 1 bag 10 was produced in the same manner as in Comparative Example A1 except that the temperature of the heat seal treatment was 200 ° C. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 124.9 kPa, the reached temperature was 101 ° C., and the required time was 144 seconds. Moreover, in the bag 10 after heating, although the wrinkle was formed in the laminated body 30, the hole was not formed.

(Example A9)
An M size type 1 bag 10 was produced in the same manner as in Comparative Example A2, except that the temperature of the heat sealing treatment was set to 200 ° C. as in Example A8. Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 125.5 kPa, the reached temperature was 102 ° C., and the required time was 141 seconds. Moreover, in the bag 10 after heating, although the wrinkle was formed in the laminated body 30, the hole was not formed. Note that the normal temperature sealing temperature in this example is 55 N as in Example A8.

(Example A10)
The same layered product 30 as in Example A9 was heat-sealed at 200 ° C., thereby producing an M-size type 1 bag 10 similar to that in Example A9. Subsequently, while measuring the pressure in the container 17 using the sensor 81, the water in the bag 10 was heated using a microwave oven with an output of 1600 W, as in Example A5. The peeling pressure was 124.8 kPa, the reached temperature was 99 ° C., and the required time was 45 seconds. Moreover, in the bag 10 after heating, although the wrinkle was formed in the laminated body 30, the hole was not formed.

(Example A11)
Using the same laminate 30 as in Example A1, an S size type 2 bag 10 was produced. Subsequently, as in Example A1, 100 ml of water was filled into the bag 10, and the upper part 11 was heat-sealed to form an upper seal part. The temperature of the heat seal process was 210 ° C. as in Example A1. In this case, the normal temperature sealing temperature is 65 N as in the case of Example A1.

  Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 110.8 kPa, the ultimate temperature was 101 ° C., and the required time was 142 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A12)
Using the same laminate 30 as in Comparative Example A1, an S size type 2 bag 10 was produced. Subsequently, as in Comparative Example A1, 100 ml of water was filled into the bag 10 and the upper part 11 was heat-sealed to form an upper seal part. The temperature of the heat sealing treatment was 210 ° C. as in Comparative Example A1. In this case, the normal temperature sealing temperature is 65 N as in the case of Comparative Example A1.

  Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 124.2 kPa, the reached temperature was 99 ° C., and the required time was 145 seconds. Moreover, in the bag 10 after heating, although the wrinkle was formed in the laminated body 30, the hole was not formed.

(Example A13)
Using the same laminate 30 as in Example A1, an S size type 3 bag 10 was produced. Subsequently, as in Example A1, 100 ml of water was filled into the bag 10, and the upper part 11 was heat-sealed to form an upper seal part. The temperature of the heat seal process was 210 ° C. as in Example A1. In this case, the normal temperature sealing temperature is 65 N as in the case of Example A1.

  Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 108.9 kPa, the ultimate temperature was 101 ° C., and the required time was 130 seconds. Moreover, in the bag 10 after heating, no holes and wrinkles were formed in the laminate 30.

(Example A14)
Using the same laminate 30 as in Comparative Example A1, an S size type 3 bag 10 was produced. Subsequently, as in Comparative Example A1, 100 ml of water was filled into the bag 10 and the upper part 11 was heat-sealed to form an upper seal part. The temperature of the heat sealing treatment was 210 ° C. as in Comparative Example A1. In this case, the normal temperature sealing temperature is 65 N as in the case of Comparative Example A1.

  Thereafter, as in Example A1, the water in the bag 10 was heated using a microwave oven with an output of 500 W while measuring the pressure in the container 17 using the sensor 81. The peeling pressure was 122.1 kPa, the reached temperature was 102 ° C., and the required time was 131 seconds. Moreover, in the bag 10 after heating, although the wrinkle was formed in the laminated body 30, the hole was not formed.

  The evaluation result in an Example and a comparative example is shown in FIG. As can be seen from the comparison between Examples A1 to A7, A11, and A13 and Comparative Examples A1 to A5, as the sealant film 70, the bag 10 was heated by using an unstretched polypropylene film ZK500 manufactured by Toray Film Processing Co., Ltd. The peeling pressure at that time could be 120 kPa or less. Thereby, it was possible to suppress the formation of a hole in the laminated body 30 of the bag 10 or the formation of wrinkles in the laminated body 30 during heating.

  In addition, as can be seen from the comparison between Example A8 and Comparative Example A1 or the comparison between Example A9 and Comparative Example A2, when the unstretched polypropylene film ZK207 manufactured by Toray Film Processing Co., Ltd. is used as the sealant film 70 Even so, by reducing the temperature of the heat sealing treatment, the peeling pressure when the bag 10 was heated could be 130 kPa or less. Thereby, it could suppress that the laminated body 30 of the bag 10 had a hole in the case of a heating.

  Further, as can be seen from the comparison between Example A12 and Comparative Example A1, the bag type is shown in FIG. 6 even when the unstretched polypropylene film ZK207 manufactured by Toray Film Processing Co., Ltd. is used as the sealant film 70. By adopting the type 2 shown, the peeling pressure when the bag 10 was heated could be 130 kPa or less. Thereby, it could suppress that the laminated body 30 of the bag 10 had a hole in the case of a heating.

  Further, as can be seen from the comparison between Example A14 and Comparative Example A1, the bag type is shown in FIG. 7 even when the unstretched polypropylene film ZK207 manufactured by Toray Film Processing Co., Ltd. is used as the sealant film 70. By adopting the type 3 shown, the peeling pressure when the bag 10 was heated could be 130 kPa or less. Thereby, it could suppress that the laminated body 30 of the bag 10 had a hole in the case of a heating.

(Examples B1 to B3)
As shown in FIG. 14, a plurality of S-size type 1 bags 10 having different positions of the inner edge 11c of the upper seal portion 11a in the second direction D2 were produced. As the laminated body 30, the same laminated body 30 as that in Example A1 was used. The temperature of the heat seal process was 210 ° C. as in Example A1.

By changing the position of the inner edge 11c of the upper seal part 11a, the distance H1 in the second direction D2 from the upper seal part 11a to the center point C of the storage part 17, and the center point of the storage part 17 from the steam release seal part 20a The shortest distance H2 to C changes. The distances H1 and H2 in Examples B1 to B3 were as follows.
Example B1: H1 = 67 mm, H2 = 60 mm
Example B2: H1 = 62 mm, H2 = 63 mm
Example B3: H1 = 57 mm, H2 = 65 mm

  Subsequently, as in the case of Example A1, while measuring the pressure in the container 17 using the sensor 81, the water in the bag 10 was heated using a microwave oven with an output of 500 W, and the peeling pressure was measured. . The results are shown in FIG. As shown in FIG. 15, there was a tendency that the peeling pressure increased as H1 / H2 decreased.

DESCRIPTION OF SYMBOLS 10 Bag 11 Upper part 11a Upper seal part 12 Lower part 12a Lower seal part 13 Side part 13a Side part seal part 14 Surface film 15 Back surface film 16 Lower film 17 Storage part 18 Contents 20 Vapor release mechanism 20a Vapor release seal part 25 Easy opening Means 26 Notch 30 Laminate 40 First Plastic Film 45 First Adhesive Layer 50 Second Plastic Film 55 Second Adhesive Layer 70 Sealant Film 81 Sensor

Claims (5)

A bag having a receiving portion,
A laminate including a sealant film located on the inner surface of the bag and at least one plastic film located on the outer surface side of the sealant film;
A seal portion that joins the inner surfaces of the pair of laminates,
The seal part is an outer edge seal part located on the outer edge of the bag, a steam release seal part located closer to the center point of the housing part than the outer edge seal part, and peeled off due to an increase in the pressure of the housing part, Have
The vapor vent seal part is a bag that peels off when the pressure of the housing part is 130 kPa or less.   The bag according to claim 1, further comprising a non-seal portion that is separated from the housing portion by the steam release seal portion and extends to reach an outer edge of the bag. The tensile elongation (%) of the sealant film in the flow direction is 800% or more,
The bag according to claim 1 or 2, wherein the tensile elongation (%) of the sealant film in the vertical direction is 1050% or more. The product of the tensile elongation (%) of the sealant film in the flow direction and the thickness (μm) of the sealant film is 45000 or more,
The bag according to any one of claims 1 to 3, wherein a product of a tensile elongation (%) of the sealant film in a vertical direction and a thickness (µm) of the sealant film is 53000 or more.   The bag according to claim 3 or 4, wherein the sealant film includes a propylene / ethylene block copolymer and an elastomer.