JP2018167906A - bag - Google Patents

Abstract

To provide a bag having piercing resistance and heat resistance.SOLUTION: The laminate constituting a bag having a steam vent mechanism includes at least a first base material, a second base material and a sealant layer in this order. One of the first base material and the second base material contains polyethylene terephthalate and the other contains polybutylene terephthalate. Between the first base material and the second base material, one containing polyethylene terephthalate has a multilayer structure part containing 51 wt% or more of polybutylene terephthalate and having ten layers or more, and the IV value of polybutylene terephthalate is between 1.10 dl/g and 1.35 dl/g inclusive.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bag provided with a steam release mechanism.

  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 a problem, for example, Patent Documents 1 to 3 provide a steam venting mechanism that automatically communicates the housing portion with the outside when the pressure of the housing portion increases and releases the steam in the housing portion to the outside. is suggesting.

Japanese Patent Laid-Open No. 10-95472 JP 2003-182780 A JP 2008-308183 A

  The laminate for constituting the bag is required to have a characteristic that prevents the bag from being broken even when a sharp member with a sharp tip contacts the bag, so-called stab resistance. For this reason, the conventional laminated body is provided with the film containing nylon which has high puncture resistance property, for example, as disclosed in Patent Documents 1 and 2. On the other hand, nylon is easy to absorb moisture and has poor heat resistance. For example, as cited as a problem in Patent Document 3, when a bag made of a laminate including a nylon layer in the middle is heated in a microwave oven, a hole may be formed in the nylon layer. Patent Document 3 proposes that both the surface layer and the intermediate layer be composed of polyethylene terephthalate (hereinafter also referred to as PET) in order to solve such a problem. However, it is considered difficult to achieve sufficient puncture resistance depending on PET.

  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 vapor venting mechanism, wherein the laminate constituting the bag includes at least a first base material, a second base material, and a sealant layer in this order, and the first base material and the first base material Of the two substrates, one includes polyethylene terephthalate, the other includes polybutylene terephthalate, and the one of the first substrate and the second substrate includes 51% by mass or more of polybutylene terephthalate. And having a multilayer structure including 10 layers or more, or having a single-layer structure, and having a polybutylene terephthalate IV value of 1.10 dl / g or more and 1.35 dl / g or less. .

  In the bag according to the present invention, the puncture strength of the laminate is preferably 13N or more.

  The bag by this invention WHEREIN: The said laminated body is a transparent vapor deposition layer provided on the said 1st base material or the said 2nd base material between the said 1st base material and the said 2nd base material, and the said transparent And a transparent gas barrier coating film provided on the vapor deposition layer. In this case, the transparent vapor deposition layer may contain aluminum oxide, and a covalent bond between an aluminum atom and a carbon atom may be formed at an interface between the first base material or the second base material and the transparent vapor deposition layer. .

  The bag by this invention WHEREIN: The said laminated body may further contain the printing layer located between the said 1st base material and the said 2nd base material.

In the bag according to the present invention, the first base material includes polyethylene terephthalate,
The second base material may contain polybutylene terephthalate. Alternatively, the first base material may include polybutylene terephthalate, and the second base material may include polyethylene terephthalate.

  In the bag according to the present invention, the sealant layer may contain 90% by mass or more of polypropylene.

  In the bag according to the present invention, the laminate further includes a first adhesive layer that is located between the first base material and the second base material and includes a cured product of a polyol and an aliphatic isocyanate compound. May be.

  In the bag according to the present invention, the laminate may further include a second adhesive layer that is located between the second base material and the sealant layer and includes a cured product of a polyol and an aliphatic isocyanate compound. Good.

  According to the present invention, the bag can be provided with puncture resistance and heat resistance.

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 sectional drawing which shows an example of the laminated constitution of the 1st film of a laminated body. It is a figure which shows an example of the measuring method of piercing strength. It is a figure which shows the layer structure and evaluation result of Examples 1-4 and Comparative Examples 1 and 2. FIG. It is sectional drawing which shows one modification of the laminated constitution of a laminated body. It is sectional drawing which shows one modification of the laminated constitution of a laminated body.

  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 being filled with the content 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 causes 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 release the steam, and suppresses the generation of steam from a place other than the steam release mechanism 20. It is configured as such. 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 side portion 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.

  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 being filled with the contents, 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. As shown in FIGS. 1 and 2, a non-seal portion 20 b is formed between the steam release seal portion 20 a and the outer edge of the side portion 13. Thereby, 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.

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 the laminated body 30 constituting the front film 14 and the back film 15.

  As shown in FIG. 3, the laminate 30 includes at least a first film 40, a second film 50, and a third film 60 in this order. The first film 40 is located on the outer surface 30y side, and the third film 60 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.

The first film 40 includes at least a first base material 41. The first film 40 may further include a print layer 42 positioned between the first base material 41 and the second base material 51. For example, the first film 40 may further include a printing layer 42 provided on the first base material 41. The second film 50 includes at least a second base material 51. The third film 60 includes at least a sealant layer 61. The first film 40 and the second film 50 are joined by a first adhesive layer 45, and the second film 50 and the third film 60 are joined by a second adhesive layer 55. Therefore, the laminate 30 according to the present embodiment includes the first base material / printing layer / first adhesive layer / second base material / second adhesive layer / sealant layer in order from the outer surface side to the inner surface side. It can be said. Note that “/” represents a boundary between layers.

  Hereinafter, the first film 40, the first adhesive layer 45, the second film 50, the second adhesive layer 55, and the third film 60 will be described in detail.

(First film)
In the example shown in FIG. 3, the first film 40 includes a first base material 41 that forms the outer surface 30 y of the laminate 30, and a printed layer 42 that is provided on the inner surface 30 x side of the first base material 41. The printed layer 42 is a layer printed on the first base material 41 in order to show product information or impart aesthetics to the bag 10. The print layer 42 expresses characters, numbers, symbols, figures, patterns, and the like. As a material constituting the printing layer 42, an ink for gravure printing or an ink for flexographic printing can be used. As a specific example of the ink for gravure printing, FINAT manufactured by DIC Graphics Corporation can be given.

  The first base material 41 includes polybutylene terephthalate (hereinafter also referred to as PBT) as a main component. For example, the first base material 41 includes 51% by mass or more of PBT. Hereinafter, advantages of the first base material 41 including PBT will be described.

  PBT is excellent in dimensional stability, and therefore excellent in printability. For this reason, the printing layer 42 can be provided on the 1st base material 41 containing PBT similarly to the case of polyethylene terephthalate (henceforth PET).

Moreover, PBT is excellent in heat resistance. For this reason, it is possible to prevent the first base material 41 from being deformed or the strength of the first base material 41 from being reduced when the bag 10 is subjected to a sterilization process such as a boil process or a retort process. The retort process is a process of heating the bag 10 in a pressurized state using steam or heated hot water after filling the bag 10 with the contents and sealing the bag 10. The temperature of retort processing is 120 degreeC or more, for example. The boil process is a process of filling the bag 10 with the contents and sealing the bag 10 and then bathing the bag 10 under atmospheric pressure. The temperature of boil processing is 90 degreeC or more and 100 degrees C or less, for example.
Moreover, when PBT has heat resistance, it can suppress that the 1st base material 41 extends by the pressure which arises in the accommodating part 17 when a consumer heats the bag 10. FIG. Thereby, the pressure generated in the housing part 17 can be effectively used as a force for peeling off the steam release seal part 20a of the steam release mechanism 20. For this reason, the vapor | steam in the accommodating part 17 can be escaped outside via the vapor removal mechanism 20 at the time of a heating.

  PBT has high strength. For this reason, the stab resistance can be given to the bag 10 similarly to the case where the laminated body which comprises the bag 10 contains nylon.

  PBT has a characteristic that it is less likely to absorb moisture than nylon. For this reason, it can suppress that the 1st base material 41 absorbs a water | moisture content and the laminate strength of the laminated body 30 falls.

  Hereinafter, the structure of the 1st base material 41 containing PBT is demonstrated in detail. In the present embodiment, as the configuration of the first base material 41 including PBT, any of the following first configuration or second configuration may be adopted.

[First Configuration of First Base Material]
The content of PBT in the first base material 41 according to the first configuration is preferably 51% by mass or more, more preferably 60% by mass or more, further 70% by mass or more, and particularly preferably 75% by mass or more. Preferably it is 80 mass% or more. By setting the content of PBT to 51% by mass or more, the first film 40 can have excellent impact strength and pinhole resistance.

  PBT used as a main constituent component is preferably 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, most preferably 100 mol% or more of terephthalic acid as a dicarboxylic acid component. Mol%. 1,4-butanediol as the glycol component is preferably 90 mol% or more, more preferably 95 mol% or more, still more preferably 97 mol% or more, and most preferably 1,4-butanediol during polymerization. It is not included except by-products generated by the ether bond of butanediol.

The first base material 41 may contain a polyester resin other than PBT. Thereby, for example, the film formability when the film-like first base material 41 is biaxially stretched and the dynamic characteristics of the first base material 41 can be adjusted.
Polyester resins other than PBT include polyester resins such as PET, polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polypropylene terephthalate (PPT), as well as isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and biphenyldicarboxylic acid. , Cyclohexanedicarboxylic acid, adipic acid, azelaic acid, PBT resin copolymerized with dicarboxylic acid such as sebacic acid, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, neopentyl glycol, 1,5 -Diols such as pentanediol, 1,6-hexanediol, diethylene glycol, cyclohexanediol, polyethylene glycol, polytetramethylene glycol, polycarbonate diol Min can be mentioned copolymerized PBT resin.

  The amount of the polyester resin other than PBT is preferably 49% by mass or less, and more preferably 40% by mass or less. If the addition amount of the polyester resin other than PBT exceeds 49% by mass, the mechanical properties as PBT may be impaired, and impact strength, pinhole resistance, and drawability may be insufficient.

  The 1st base material 41 may contain the polyester-type and polyamide-type elastomer which copolymerized at least any one of the flexible polyether component, the polycarbonate component, and the polyester component as an additive. Thereby, the pinhole resistance at the time of bending can be improved. The additive amount of the additive is, for example, 20% by mass. When the additive amount exceeds 20% by mass, the effect as the additive may be saturated, or the transparency of the first base material 41 may be reduced.

  An example of a method for producing the film-like first base material 41 according to the first configuration will be described. Here, a method for producing the film-like first base material 41 by a casting method will be described. More specifically, a method of casting a resin having the same composition in multiple layers during casting will be described.

Since PBT has a high crystallization speed, crystallization proceeds even during casting. At this time, when cast as a single layer without being multi-layered, there is no barrier that can suppress the growth of the crystal, so the crystal grows to a large size, and the resulting unstretched original fabric is obtained. The yield stress of becomes higher. For this reason, it becomes easy to fracture when the unstretched original fabric is biaxially stretched. Moreover, it is possible that the yield stress of the obtained biaxially stretched film becomes high and the moldability of the biaxially stretched film becomes insufficient.
On the other hand, if the same resin is multilayered at the time of casting, the stretching stress of the unstretched sheet can be reduced. For this reason, stable biaxial stretching is possible, and the yield stress of the obtained biaxially stretched film is reduced. Thereby, a flexible and high breaking strength film can be obtained.

  FIG. 4 is a cross-sectional view showing an example of the layer configuration of the first film. When the first substrate 41 is produced by casting the resin in multiple layers, as shown in FIG. 4, the first substrate 41 of the first film 40 is composed of a multilayer structure including a plurality of layers 41a. . Each of the plurality of layers 41a includes PBT as a main component. For example, each of the plurality of layers 41a preferably includes 51% by mass or more of PBT, and more preferably includes 60% by mass or more of PBT. In the plurality of layers 41a, the (n + 1) th layer 41a is directly stacked on the nth layer 41a. That is, no adhesive layer or adhesive layer is interposed between the plurality of layers 41a.

  The reason why the characteristics of the PBT film are improved by the multilayering is estimated as follows. When the resins are laminated, even if the resin composition is the same, a layer interface exists, and crystallization is accelerated by the interface. On the other hand, the growth of large crystals beyond the layer thickness is suppressed. For this reason, it is considered that the size of the crystal (spherulite) becomes small.

  As a specific method for reducing the size of spherulites by multilayering, a general multilayering apparatus (multilayer feedblock, static mixer, multilayer multimanifold, etc.) can be used. For example, for example, a method of laminating thermoplastic resins sent out from different flow paths using two or more extruders using a feed block, a static mixer, a multi-manifold die, or the like can be used. . In addition, when multilayering resin of the same composition, it is also possible to introduce the above multilayering apparatus into the melt line from the extruder to the die using only one extruder.

  The first substrate 41 is composed of a multilayer structure including at least 10 layers, preferably 60 layers or more, more preferably 250 layers or more, and still more preferably 1000 layers or more. By increasing the number of layers, the size of spherulites in the unstretched raw PBT can be reduced, and the subsequent biaxial stretching can be carried out stably. Moreover, the yield stress of PBT in the state of a biaxially stretched film can be made small. Preferably, the diameter of the spherulite in the unstretched raw PBT is 500 nm or less.

  The stretching temperature (hereinafter also referred to as MD stretching temperature) in the longitudinal stretching direction (hereinafter referred to as MD) when producing a biaxially stretched film by biaxially stretching the unstretched raw material of PBT is preferably 40 ° C. or higher. Yes, more preferably 45 ° C or higher. By setting the MD stretching temperature to 40 ° C. or higher, the film can be prevented from being broken. Moreover, MD extending | stretching temperature becomes like this. Preferably it is 100 degrees C or less, More preferably, it is 95 degrees C or less. The phenomenon that the orientation of the biaxially stretched film does not occur can be suppressed by setting the MD stretching temperature to 100 ° C. or lower.

  The draw ratio in MD (hereinafter also referred to as MD draw ratio) is preferably 2.5 times or more. Thereby, a biaxially stretched film can be oriented and a favorable mechanical characteristic and uniform thickness can be implement | achieved. MD stretch ratio is 5 times or less, for example.

  The stretching temperature (hereinafter also referred to as TD stretching temperature) in the transverse stretching direction (hereinafter also referred to as TD) is preferably 40 ° C. or higher. By setting the TD stretching temperature to 40 ° C. or higher, the film can be prevented from being broken. The TD stretching temperature is preferably 100 ° C. or lower. By setting the TD stretching temperature to 100 ° C. or lower, the phenomenon that the orientation of the biaxially stretched film does not occur can be suppressed.

  The draw ratio in TD (hereinafter also referred to as TD draw ratio) is preferably 2.5 times or more. Thereby, a biaxially stretched film can be oriented and a favorable mechanical characteristic and uniform thickness can be implement | achieved. MD stretch ratio is 5 times or less, for example.

  The TD relaxation rate is preferably 0.5% or more. Thereby, it can suppress that a fracture | rupture arises at the time of heat setting of the biaxially stretched film of PBT. The TD relaxation rate is preferably 10% or less. Thereby, sagging etc. arise in a biaxially stretched film of PBT, and it can control that thickness unevenness generate | occur | produces.

The thickness of the layer 41a of the first base material 41 shown in FIG. 4 is preferably 3 nm or more, more preferably 10 nm or more. The thickness of the layer 41a is preferably 200 nm or less, and more preferably 100 nm or less.
Further, the thickness of the first base material 41 is preferably 9 μm or more, and more preferably 12 μm or more. Further, the thickness of the first base material 41 is preferably 25 μm or less, and more preferably 20 μm or less. By setting the thickness of the first base material 41 to 9 μm or more, the first base material 41 has sufficient strength. Moreover, the 1st base material 41 comes to show the moldability which was excellent by making the thickness of the 1st base material 41 into 25 micrometers or less. For this reason, the process which processes the laminated body 30 containing the 1st base material 41 and manufactures the bag 10 can be implemented efficiently.

[Second Configuration of First Base Material]
The 1st base material 41 concerning the 2nd composition consists of a single layer film containing polyester which makes butylene terephthalate the main repeating unit. For example, the first base material 41 is mainly composed of 1,4-butanediol as a glycol component, or an ester-forming derivative thereof, and terephthalic acid as a dibasic acid component, or an ester-forming derivative thereof. Includes homo- or copolymer-type polyesters obtained by condensation. The content of PBT in the first base material 41 according to the second configuration is preferably 51% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and further preferably 80% by mass or more, Most preferably, it is 90 mass% or more. Moreover, it is preferable that the 1st base material 41 which concerns on a 2nd structure is comprised only with the polybutylene terephthalate and the additive.

  In order to impart mechanical strength to the first base material 41, the melting point of the PBT is 200 ° C. or more and 250 ° C. or less, and the IV value (intrinsic viscosity) is 1.10 dl / g or more and 1.35 dl / g or less. Are preferred. Furthermore, those having a melting point of 215 ° C. or more and 225 ° C. or less and an IV value of 1.15 dl / g or more and 1.30 dl / g or less are particularly preferable. These IV values may be satisfied by the entire material constituting the first base material 41. The IV value can be calculated based on JIS K 7367-5: 2000.

The 1st base material 41 concerning the 2nd composition may contain polyester resins other than PBT, such as PET, in the range of 30 mass% or less. When the 1st base material 41 contains PET in addition to PBT, PBT crystallization can be suppressed and the extending | stretching workability of a PBT film can be improved. As PET mix | blended with PBT of the 1st base material 41, polyester which uses ethylene terephthalate as the main repeating unit can be used. For example, a homotype mainly composed of ethylene glycol as a glycol component and terephthalic acid as a dibasic acid component can be preferably used. In order to impart good mechanical strength characteristics, among PET, those having a melting point of 240 ° C. or more and 265 ° C. or less and an IV value of 0.55 dl / g or more and 0.90 dl / g or less are preferable. Furthermore, those having a melting point of 245 ° C. or more and 260 ° C. or less and an IV value of 0.60 dl / g or more and 0.80 dl / g or less are particularly preferable.
By setting the blending amount of PET to 30% by mass or less, it is possible to suppress the unstretched raw fabric and the stretched film from becoming too rigid. Thereby, a stretched film becomes brittle and it can suppress that the pressure resistance strength, impact strength, puncture strength, etc. of a stretched film fall. Moreover, it is possible to suppress the occurrence of stretching failure when the unstretched raw fabric is stretched.

  The first base material 41 is made of a lubricant, an antiblocking agent, an inorganic extender, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant, a plasticizer, a colorant, a crystallization inhibitor, and a crystallization as necessary. Additives such as accelerators may be included. Further, the polyester resin pellet used as a raw material of the first base material 41 has a moisture content of 0.05% by weight or less, preferably 0.01% by weight before heating and melting in order to avoid a decrease in viscosity due to hydrolysis during heating and melting. It is preferable to use after sufficiently pre-drying so as to be not more than%.

  An example of a method for producing the film-like first base material 41 according to the second configuration will be described.

  In order to stably produce the film of the first base material 41 having the above-described configuration, it is important to suppress the crystal growth in the unstretched raw fabric state. Specifically, when forming the film by cooling the extruded PBT melt, the crystallization temperature region of the polymer is cooled at a certain rate or more, that is, the raw fabric cooling rate is an important factor. The raw fabric cooling rate is, for example, 200 ° C./second or more, preferably 250 ° C./second or more, particularly preferably 350 ° C./second or more. Since the unstretched original film formed at a high cooling rate maintains a low crystalline state, the stability of the bubbles during stretching is improved. Furthermore, since film formation at high speed is possible, film productivity is also improved. When the cooling rate is less than 200 ° C./sec, it is considered that the crystallinity of the obtained unstretched original fabric is increased and the stretchability is lowered. In extreme cases, the stretching bubble may burst and stretching may not continue.

  The unstretched original fabric containing PBT as a main component is preferably transported to a space where biaxial stretching is performed while maintaining the atmospheric temperature at 25 ° C. or lower, preferably 20 ° C. or lower. Thereby, even if it is a case where residence time becomes long, the crystallinity of the unstretched original fabric immediately after film-forming can be maintained.

  The biaxial stretching method for obtaining a stretched film by stretching an unstretched raw fabric is not particularly limited. For example, the longitudinal direction and the lateral direction may be simultaneously stretched by the tubular method or the tenter method, or the longitudinal direction and the lateral direction may be sequentially stretched. Among these, the tubular method can obtain a stretched film having a good balance of physical properties in the circumferential direction, and is particularly preferably employed.

  In the tubular method, the unstretched raw material guided to the stretching space is inserted between a pair of low-speed nip rolls, and then heated by a stretching heater while air is pressed into the unstretched raw fabric. After stretching, air is blown onto the stretched film by a cooling shoulder air ring. The stretching ratio is preferably 2.7 times or more and 4.5 times or less for MD and TD, respectively, in consideration of stretching stability, strength physical properties of the stretched film, transparency, and thickness uniformity. By setting the draw ratio to 2.7 times or more, it is possible to sufficiently ensure the tensile elastic modulus and impact strength of the stretched film. In addition, by setting the draw ratio to 4.5 times or less, it is possible to suppress the occurrence of excessive molecular chain distortion due to stretching, and to suppress the occurrence of breakage and puncture during the stretching process, so that the stretched film can be stabilized. Can be produced.

  The stretching temperature is preferably 40 ° C. or higher and 80 ° C. or lower, and particularly preferably 45 ° C. or higher and 65 ° C. or lower. Since the unstretched original fabric produced at the above-described high cooling rate has low crystallinity, the unstretched original fabric can be stably stretched even when the stretching temperature is relatively low. Further, by setting the stretching temperature to 80 ° C. or less, it is possible to suppress stretching bubble shaking and obtain a stretched film with good thickness accuracy. In addition, by setting the stretching temperature to 40 ° C. or higher, it is possible to suppress the occurrence of excessive stretch-oriented crystallization due to low-temperature stretching, thereby preventing whitening of the film.

  The 1st base material 41 produced as mentioned above is comprised by the single layer containing polyester which makes butylene terephthalate the main repeating unit, for example. According to the above-described production method, since the unstretched raw film is formed at a high cooling rate, even when the unstretched raw fabric is constituted by a single layer, a low crystalline state can be maintained, For this reason, an unstretched original fabric can be extended | stretched stably.

(First adhesive layer)
The first adhesive layer 45 includes a first adhesive for bonding the first film 40 and the second film 50. Examples of the first adhesive include ether-based two-component reactive adhesives and ester-based two-component reactive adhesives.

  Examples of the ether-based two-component reactive adhesive include polyether 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. 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.

  Examples of the ester-based two-component reactive adhesive include polyester polyurethane and polyester. 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. Examples of the isocyanate compound are the same as in the case of the ether-based two-component reactive adhesive described above.

(Second film)
The second film 50 includes at least a second base material 51. The 2nd base material 51 contains PET as a main component. For example, the 2nd base material 51 contains 51 mass% or more of PET. The 2nd base material 51 can have heat resistance because the 2nd base material 51 contains PET. For example, compared with the case where the 2nd base material 51 contains nylon, melting | fusing point of the 2nd base material 51 becomes high, and the hygroscopic property of the 2nd base material 51 becomes low. Thereby, when heating the bag 10 with a microwave oven, it can suppress that a hole opens in the 2nd base material 51 resulting from the overheated water. Moreover, the heat resistance of PET is higher than the heat resistance of PBT. For this reason, according to this Embodiment, compared with the case where the 2nd base material 51 consists of PBT, the heat resistance of the laminated body 30 can be improved. Thereby, for example, when the bag 10 is heated with a microwave oven and the temperature of the contents becomes high, it is possible to prevent the laminated body 30 from being damaged and the performance of the laminated body 30 from being deteriorated.

  The thickness of the second substrate 51 is preferably 9 μm or more, and more preferably 12 μm or more. The thickness of the second substrate 51 is preferably 25 μm or less, more preferably 20 μm or less. By setting the thickness of the second base material 51 to 9 μm or more, the second base material 51 has sufficient strength. Moreover, the 2nd base material 51 comes to show the outstanding moldability by the thickness of the 2nd base material 51 being 25 micrometers or less. For this reason, the process which processes the laminated body 30 and manufactures the bag 10 can be implemented efficiently.

(Second adhesive layer)
The second adhesive layer 55 includes a second adhesive for bonding the second film 50 and the third film 60. Examples of the second adhesive include ether-based two-component reaction type adhesives. Examples of the ether-based two-component reaction type adhesive include polyurethane as in the case of the first adhesive. Polyurethane is a cured product produced by a reaction between a polyol as a main agent and an isocyanate compound as a curing agent. In addition, although polyether polyol and polyester polyol can be used as polyol, it is preferable to use polyester polyol.

  As described above, aromatic isocyanate compounds and aliphatic isocyanate compounds exist as isocyanate compounds. 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 2nd adhesive bond layer 55 is in contact with the 3rd film 60, as shown in FIG. For this reason, when the 2nd adhesive bond layer 55 contains an aromatic isocyanate compound, the component eluted from the aromatic isocyanate compound may adhere to the content of the bag 10 comprised by the laminated body 30. FIG.

  In consideration of such problems, as a second adhesive constituting the second adhesive layer 55, a cured product generated by a reaction between a polyol as a main agent and an aliphatic isocyanate compound as a curing agent is used. Suggest to use. 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.

  In the case where the second film 50 does not have a barrier property such as a gas barrier property, and the first adhesive layer 45 includes an aromatic isocyanate compound, it was eluted from the aromatic isocyanate compound. It is also conceivable that components adhere to the contents. In this case, as in the case of the second adhesive layer 55, the polyol as the main agent and the aliphatic isocyanate compound as the curing agent react as the first adhesive constituting the first adhesive layer 45. It is preferable to use a cured product produced by the above.

(Third film)
The third film 60 includes at least a sealant layer 61 that constitutes the inner surface 30 x of the laminate 30. As a material constituting the sealant layer 61, one or two or more resins selected from polyethylene such as low density polyethylene and linear low density polyethylene, and polypropylene can be used. The sealant layer 61 may be a single layer or a multilayer. The sealant layer 61 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.

  As described above, the bag 10 composed of the laminate 30 is subjected to sterilization treatment such as boil treatment and retort treatment at a high temperature. Therefore, as the sealant layer 61, a layer having heat resistance that can withstand processing at these high temperatures is used.

  The melting point of the material constituting the sealant layer 61 is preferably 150 ° C. or higher, and more preferably 160 ° C. or higher. By increasing the melting point of the sealant layer 61, the bag 10 can be retorted at a high temperature, and the time required for the retort process can be shortened. The melting point of the material constituting the sealant layer 61 is lower than the melting point of the resin constituting the first base member 41 and the melting point of the resin constituting the second base member 51.

  When considering from the viewpoint of retort processing, a material mainly composed of propylene can be used as the material constituting the sealant layer 61. 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 by 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 layer 61 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 layer from the viewpoint of the above retort processing. The material constituting the sealant layer 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 layer, 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 for forming a sealant layer 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. As a specific example of the sealant film for constituting a sealant layer having a melting point of 105 ° C. or higher, NB-1 manufactured by Tamapoli can be cited. Specific examples of the sealant film for forming a sealant layer 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 layer 61 includes a propylene / ethylene block copolymer. For example, the third film 60 including the sealant layer 61 is an unstretched film containing a propylene / ethylene block copolymer as a main component. By using the propylene / ethylene block copolymer, the impact resistance of the third film 60 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.

  The sealant layer 61 may further contain a thermoplastic elastomer. By using the thermoplastic elastomer, the impact resistance and puncture resistance of the third film 60 can be further improved.

  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 layer 61 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 layer 61 is preferably 30 μm or more, more preferably 40 μm or more. Moreover, the thickness of the sealant layer 61 is preferably 100 μm or less, and more preferably 80 μm or less.

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 Manufacturing First Film Next, an example of a method for manufacturing the first film 40 will be described.

  First, a resin material containing PBT as a main component is prepared. Then, the film-form 1st base material 41 is produced by extruding resin material by melt extrusion methods, such as a cast method and a tubular method. Subsequently, the print layer 42 is formed on the first base material 41. Thus, the 1st film 40 provided with the 1st base material 41 and the printing layer 42 can be obtained.

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

  First, the first film 40 and the second film 50 described above are prepared. Subsequently, the first film 40 and the second film 50 are laminated via the first adhesive layer 45 by a dry laminating method. Thereafter, the laminate including the first film 40 and the second film 50 and the third film 60 are laminated via the second adhesive layer 55 by a dry laminating method. Thereby, the laminated body 30 provided with the 1st film 40, the 2nd film 50, and the 3rd film 60 can be obtained.

  Alternatively, first, the second film 50 and the third film 60 are laminated via the second adhesive layer 55, and then the first film 40 and the laminate including the second film 50 and the third film 60 are first laminated. The laminated body 30 may be manufactured by laminating via one adhesive layer 45.

Manufacturing method of bag The front film 14 and the back film 15 which consist of the above-mentioned 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 and the side seal portion 13a. 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. 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, the bag 10 in which the contents 18 are accommodated and sealed can be obtained.

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 this Embodiment, the laminated body 30 which comprises the surface film 14 and the back film 15 contains the 1st base material 41 which has PBT as a main component. For this reason, the rigidity of the first base material 41 is high, and as a result, when the front film 14 and the back film 15 receive force, the first base material 41 in the front film 14 and the back film 15 extends. Can be suppressed. Thereby, the force generated due to the pressure generated in the housing portion 17 can be mainly used as a force for peeling off the steam release seal portion 20a, not a force for extending the front film 14 and the back film 15. it can. For this reason, the force added to the steam release seal | sticker part 20a can be enlarged. Thus, the steam release seal portion 20a is easily peeled off during heating, and the steam in the housing portion 17 can be released to the outside via the steam release mechanism 20.

In addition, the laminated body 30 which comprises the surface film 14 and the back surface film 15 of the bag 10 contains the 1st base material 41 which has PBT as a main component, and there can exist the following effect.
First, PBT is excellent in printability. For this reason, the printing layer 42 can be provided on the 1st base material 41 containing PBT similarly to the case of polyethylene terephthalate (henceforth PET).
Moreover, PBT is excellent in heat resistance. For this reason, when performing the boil process and the retort process to the bag 10, it can suppress that the 1st base material 41 deform | transforms or the intensity | strength of the 1st base material 41 falls.
PBT has high strength. For this reason, the puncture strength of the laminated body 30 and the bag 10 can be increased similarly to the case where the laminated body constituting the bag 10 includes nylon. The puncture strength of the laminate 30 is preferably 13N or more, more preferably 15N or more, and further preferably 17N or more. A method for measuring the piercing strength will be described in Example 1 to be described later. Further, PBT has a characteristic that it is less likely to absorb moisture than nylon. For this reason, even if it is a case where the 1st substrate 41 containing PBT is arranged on the outer surface 30y of layered product 30, the first substrate 41 will absorb moisture and the laminate strength of layered product 30 will fall. Can be suppressed.

  Moreover, the laminated body 30 which comprises the surface film 14 and the back surface film 15 of the bag 10 contains the 2nd base material 51 which has PET as a main component, compared with the case where the 2nd base material 51 consists of PBT, The heat resistance of the laminate 30 can be increased. Thereby, for example, when the bag 10 is heated in a microwave oven and the temperature of the contents is increased, the surface film 14 and the back film 15 are prevented from being damaged and the performance of the surface film 14 and the back film 15 is reduced. can do.

  Moreover, according to this Embodiment, the sealant layer 61 of the laminated body 30 which comprises the surface film 14 and the back film 15 of the bag 10 contains a propylene and ethylene block copolymer. For this reason, the impact resistance and puncture resistance of the bag 10 can be enhanced.

  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 modified example, the description thereof may be omitted.

(Modification of layer structure)
In the present embodiment described above, the first base material 41 includes 51% by mass or more of PBT, and the second base material 51 includes 51% by mass or more of PET, whereby the stab resistance and heat resistance of the stacked body 30. The example which raises is shown. However, the present invention is not limited to this, and the first substrate 41 includes 51% by mass or more of PET, and the second substrate 51 includes 51% by mass or more of PBT. You may increase the nature. As the PBT of the second base material 51, the PBT according to the first configuration described in the first base material 41 or the PBT according to the second configuration can be used.

  The fact that the second base material 51 contains 51% by mass or more of PBT and the first base material 41 contains 51% by mass or more of PET contributes to the improvement of the dimensional stability and printability of the laminate 30.

  Moreover, both the 1st base material 41 and the 2nd base material 51 may contain 51 mass% or more of PBT. Also as PBT in this case, PBT which concerns on the 1st structure demonstrated with the above-mentioned 1st base material 41, or PBT which concerns on a 2nd structure can be used.

Table 1 summarizes examples of combinations of materials constituting the first base material 41 and the second base material 51. In Table 1, the notation “PBT” means that 51 mass% or more of PBT is contained in the resin constituting the film of the first base material 41 or the second base material 51. In Table 1, the expression “PET” means that 51% by mass or more of PET is contained in the resin constituting the film of the first base material 41 or the second base material 51.

  Further, in the above-described embodiment, the example in which the printing layer 42 is provided on the inner surface 30x side of the first base material 41 is shown, but the present invention is not limited to this, and the outer surface 30y side of the first base material 41 is provided. The printing layer 42 may be provided on the surface. Further, the print layer 42 may not be provided on the first base material 41.

  Moreover, the transparent vapor deposition layer 36 which consists of an inorganic material which has transparency in the position between the 1st base material 41 and the 2nd base material 51 is provided in the 1st base material 41 or / and the 2nd base material 51. It may be. The transparent vapor deposition layer 36 may be provided on the surface on the inner surface 30x side of the first base material 41 as shown in FIG. 7, and the surface on the outer surface 30y side of the second base material 51 as shown in FIG. May be provided. A transparent gas barrier coating film 37 having transparency may be provided on the transparent vapor deposition layer 36.

  The transparent vapor deposition layer 36 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 36 may be provided. When it has two or more transparent vapor deposition layers 36, each may have the same composition or different compositions. As a method for forming the transparent vapor deposition layer 36, 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, or a plasma chemical vapor deposition method, The chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) etc., such as a thermal chemical vapor deposition method and a photochemical vapor deposition method, can be mentioned. Specifically, a vapor deposition layer can be formed on a film formation roller using a roller-type vapor deposition film forming apparatus.

  The transparent vapor deposition layer 36 is formed of an inorganic material having transparency, such as aluminum oxide (aluminum oxide) and silicon oxide. As the transparent vapor deposition layer 36, it is preferable to use an amorphous thin film of aluminum oxide. Specifically, the transparent vapor deposition layer 36 is an amorphous thin film of aluminum oxide represented by the formula AlOX (wherein X represents a number in the range of 0.5 to 1.5). As the transparent vapor-deposited layer 36, an amorphous thin film of aluminum oxide in which the value of X decreases in the depth direction from the film surface toward the inner surface can be used. The amorphous thin film of aluminum oxide is represented by the formula AlOX (wherein X represents a number in the range of 0.5 to 1.5), and proceeds in the depth direction from the thin film surface toward the inner surface. It is preferable that the value of X increases. In addition, as a value of X in the above formula, a value of X = 0.5 or more can be basically used. However, when X is less than 1.0, coloring is intense and transparent. Since it is inferior in property, it is preferable to use the thing of X = 1.0 or more. Moreover, since the thing of X = 1.5 is a thing in which Al and oxygen were completely oxidized, the thing to X = 1.5 can be used as an upper limit. In addition, when the value of X in said formula is 0, it is a perfect inorganic simple substance (pure substance), and is not transparent.

  Note that the rate of decrease in the value of X is determined by using a surface analyzer such as an X-ray photoelectron spectrometer (XPS) or a secondary ion mass spectrometer (SIMS) in the depth direction. This can be confirmed by performing an elemental analysis of the transparent vapor deposition layer 36 using a method of analyzing by ion etching or the like.

  The transparent vapor deposition layer 36 may be a layer made of a mixture of inorganic compounds containing a covalent bond between an aluminum atom and a carbon atom. In this case, the transparent vapor deposition layer 36 uses an X-ray photoelectron spectrometer (measuring conditions: X-ray source AlKα, X-ray output 120 W) and shares aluminum atoms and carbon atoms at the peak measured by ion etching in the depth direction. It may have a gas barrier property that indicates the presence of a bond and has transparency and prevents permeation of oxygen, water vapor, and the like.

  A covalent bond between a metal atom and a carbon atom may be formed at the interface between the transparent vapor deposition layer 36 and the first base material 41 or the second base material 51. For example, when the transparent vapor deposition layer 36 contains aluminum oxide, a covalent bond between an aluminum atom and a carbon atom is formed at the interface between the first base material 41 or the second base material 51 and the transparent vapor deposition layer 36. can do. The covalent bond can be detected by measurement by X-ray photoelectron spectroscopy (hereinafter referred to as “XPS measurement” for short).

  Further, in the transparent vapor deposition layer 36, the existence ratio of the covalent bond between the aluminum atom and the carbon atom is observed when the interface between the transparent vapor deposition layer 36 and the first base material 41 or the second base material 51 is measured by XPS measurement. It is preferable that it is within the range of 0.3% or more and 30% or less of all the bonds containing carbon atoms. Thereby, the adhesiveness of the transparent vapor deposition layer 36 and the 1st base material 41 or the 2nd base material 51 is strengthened, transparency is excellent, and the thing of the performance with the balance as a gas barrier property vapor deposition film is obtained.

  If the abundance ratio of the covalent bond between the aluminum atom and the carbon atom is less than 0.3%, the adhesion of the transparent vapor-deposited layer 36 is not sufficiently improved, and it is difficult to stably maintain the barrier property.

Further, the AL (aluminum) / O (oxygen) ratio of the transparent vapor-deposited layer 36 mainly composed of aluminum oxide is such that the first substrate 41 or the second substrate 51 and the transparent vapor-deposited layer 36 are In the range up to 3 nm toward the surface of the transparent vapor deposition layer 36 on the side opposite to the base 41 or the second base 51, it is preferably 1.0 or less.
In the range from the interface between the transparent vapor deposition layer 36 and the first base material 41 or the second base material 51 toward the surface of the transparent vapor deposition layer 36 on the side opposite to the first base material 41 or the second base material 51, AL When the ratio of / O exceeds 1.0, the adhesion between the first base material 41 or the second base material 51 and the transparent vapor deposition layer 36 becomes insufficient, and the ratio of aluminum increases, so that the transparent vapor deposition layer 36 The transparency of the is reduced.

  The thickness of the transparent vapor deposition layer 36 is, for example, 30 mm or more and 150 mm. If it is less than 30 mm, the gas barrier property may be insufficient even when the transparent gas barrier coating film 37 is used in combination. On the other hand, if it exceeds 150 mm, the gas barrier performance of the laminate 30 may not be maintained. The reason for this is not clear, but if the thickness of the transparent vapor deposition layer 36 exceeds 150 mm, the flexibility of the laminate 30 is reduced, and when the laminate 30 is used in the bag 10, a part of the transparent vapor deposition layer 36 is not cracked. It is considered that pinholes are generated and gas barrier properties are lowered. The thickness of the transparent vapor deposition layer 36 is preferably 40 mm or more and 130 mm or less, more preferably 50 mm or more and 120 mm or less. The thickness of the transparent vapor-deposited layer 36 can be measured by a fundamental parameter method using, for example, a fluorescent X-ray analyzer (trade name: RIX2000 type, manufactured by Rigaku Corporation). Moreover, as a means to change the thickness of the transparent vapor deposition layer 36, it can carry out by the method of changing the deposition rate of the transparent vapor deposition layer 36, the method of changing the vapor deposition rate, etc.

  When forming the transparent vapor deposition layer 36 on the 1st base material 41 or the 2nd base material 51, pre-processes, such as a corona discharge process, a flame process, a plasma process, are previously carried out on the surface of the 1st base material 41 or the 2nd base material 51. You may give it. In particular, when a covalent bond between a metal atom and a carbon atom is formed at the interface between the transparent vapor deposition layer 36 and the first base material 41 or the second base material 51, the first group on which the transparent vapor deposition layer 36 is to be formed. Pretreatment is preferably performed on the surface of the material 41 or the second base material 51. When the pretreatment is plasma treatment, plasma is supplied to the surface of the first base material 41 or the second base material 51 by a pretreatment device in a reduced pressure environment of 0.1 Pa or more and 100 Pa or less. Plasma uses an inert gas such as argon alone or a mixed gas of oxygen, nitrogen, carbon dioxide and one or more of them as a plasma source gas, and the plasma source gas is excited by a potential difference due to a high-frequency voltage or the like. By doing so, it can be generated.

  By the pretreatment, the plasma can be confined in the vicinity of the surface of the first base material 41 or the second base material 51. Thereby, the shape of the surface of the 1st substrate 41 or the 2nd substrate 51, a chemical bond state, and a functional group are changed, and the chemical property of the surface of the 1st substrate 41 or the 2nd substrate 51 is changed. Can be changed. This makes it possible to improve the adhesion between the first base material 41 or the second base material 51 and the transparent vapor deposition layer 36.

The transparent gas barrier coating film 37 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 37 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, and M represents a metal atom). , N represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents a valence of M), and a polyvinyl alcohol as described above A transparent gas barrier composition containing a benzene-based 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, acid, water, and an organic solvent. can get.

As the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , at least one kind of a partial hydrolyzate of alkoxide and a condensate of hydrolysis of alkoxide can be used. Moreover, as a partial hydrolyzate of said alkoxide, all the alkoxy groups do not need to be hydrolyzed, The thing by which 1 or more was hydrolyzed, and its mixture may be sufficient. As a condensate of hydrolysis of alkoxide, a dimer or more of partially hydrolyzed alkoxide, specifically, a 2 to 6 mer is used.

In the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , as the metal atom represented by M, silicon, zirconium, titanium, aluminum, and the like can be used. Examples of preferable metals include silicon and titanium. In the present invention, alkoxides may be used alone or in combination of two or more different metal atom alkoxides in the same solution.

In the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ¹ include, for example, a methyl group, an ethyl group, an n-propyl group, i Examples thereof include alkyl groups such as -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group and others. In the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ² include, for example, a methyl group, an ethyl group, an n-propyl group, i -Propyl group, n-butyl group, sec-butyl group, and the like. These alkyl groups in the same molecule may be the same or different.

  When preparing said transparent gas barrier composition, you may add a silane coupling agent etc., for example. As said silane coupling agent, known organic reactive group containing organoalkoxysilane can be used. In particular, an organoalkoxysilane having an epoxy group is preferably used. Specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be used. The above silane coupling agents may be used alone or in combination of two or more.

(Bag variant)
In the above-described embodiment, an example in which the bag 10 is a gusset type bag has been shown, but the specific configuration of the bag 10 is not particularly limited. For example, the bag 10 may be a so-called pillow bag produced by forming a back-sealed seal portion so that a single laminate is formed into a cylindrical shape. The bag 10 may be a four-side sealed bag or a three-side sealed bag.

  Further, in the above-described embodiment, an example in which the steam release mechanism 20 is configured by the steam release seal portion 20a having a shape protruding from the side seal portion 13a toward the inside of the bag 10 has been described. However, the specific configuration of the steam release mechanism 20 is not particularly limited as long as the steam in the housing portion 17 can be appropriately discharged to the outside. For example, when the bag 10 is a pillow bag, the steam release mechanism 20 may be configured by a part of the back-sealed seal portion as in the case of Patent Document 1 described above.

  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.

Example 1
A film-like first base material 41 including a plurality of layers 41a described in the first configuration and manufactured by a casting method was prepared. The content of PBT in each layer 41a was 80%, the number of layers 41a was 1024, and the thickness of the first base material 41 was 15 μm. Subsequently, the print layer 42 was formed on the film-like first base material 41 using a finart manufactured by DIC Graphics Corporation.

  Moreover, the film-like 2nd film 50 containing the 2nd base material 51 was prepared. As the 2nd base material 51, what contains 100 mass% PET was used. The thickness of the second substrate 51 was 12 μm.

  A film-like third film 60 including the sealant layer 61 was prepared. As the sealant layer 61, an unstretched polypropylene film ZK207 manufactured by Toray Film Processing Co., Ltd. was used. The thickness of the sealant layer 61 was 60 μm.

  Next, the first film 40 and the second film 50 were laminated by the dry laminating method through the first adhesive layer 45. As the first adhesive layer 45, a two-component polyurethane adhesive (main agent: RU-40, curing agent: H-4) manufactured by Rock Paint Co., Ltd. was used. RU-40 contains a polyester polyol. H-4 contains an aliphatic isocyanate compound. The thickness of the first adhesive layer 45 was 3 μm.

  Next, the laminated body of the 1st film 40 and the 2nd film 50, and the 3rd film 60 were laminated | stacked by the dry lamination method, and the laminated body 30 was obtained. As the second adhesive layer 55, similarly to the first adhesive layer 45, a two-component polyurethane adhesive (main agent: RU-40, curing agent: H-4) manufactured by Rock Paint Co., Ltd. was used. The thickness of the second adhesive layer 55 was 3 μm.

  Subsequently, the piercing strength of the laminate 30 was measured in accordance with JIS Z1707 7.4. As a measuring device, Tensilon universal material testing machine RTC-1310 manufactured by A & D was used. Specifically, as shown in FIG. 5, a semicircular needle 70 having a diameter of 1.0 mm and a tip shape radius of 0.5 mm from the outer surface 30y side with respect to the test piece of the laminated body 30 in a fixed state. Was stabbed at a speed of 50 mm / min (50 mm per minute), and the maximum value of the stress until the needle 70 penetrated the laminate 30 was measured. About five or more test pieces, the maximum value of stress was measured, and the average value was defined as the piercing strength of the laminate 30. The environment during the measurement was a temperature of 23 ° C. and a relative humidity of 50%. As a result, the piercing strength was 17N.

  Then, the bag 10 was produced using the laminated body 30, and the vapor permeability of the bag 10 was evaluated. Specifically, first, the bag 10 shown in FIG. The length S1 of the bag 10 was 145 mm, and the length S2 was 140 mm. Thereafter, 100 g of water was filled into the bag 10 and the upper part 11 was heat-sealed to form an upper seal part. Subsequently, the contents are heated for 1 minute using a microwave oven with an output of 1600 W, whether or not a hole is opened in the laminated body 30, and whether or not the steam vent seal portion 20a of the steam vent mechanism 20 is appropriately peeled off. I confirmed it. As a result, no hole was formed in the laminate 30. Moreover, the steam release seal part 20a peeled off, and the steam in the storage part 17 was able to escape to the outside. That is, the evaluation results of both heat resistance and steamability were good.

(Example 2)
As the first base material 41 of the first film 40, the PBT containing 100% by mass described in the second configuration is included, the melting point of the PBT is 224 ° C., the IV value is 1.26 dl / g, and the tubular A laminate 30 was produced in the same manner as in Example 1 except that the single-layer film produced by the method was used. The first substrate 41 was a single layer film composed only of PBT and additives, and the thickness of the first substrate 41 was 15 μm.

  Subsequently, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 17N. Further, in the same manner as in Example 1, the heat resistance and vapor permeability of the bag 10 produced using the laminate 30 were evaluated. As a result, both evaluation results of heat resistance and steamability were good.

(Example 3)
Example 1 except that PBT constituting the first base material 41 of Example 1 was used as the second base material 51 and PET constituting the second base material 51 of Example 1 was used as the first base material 41 The laminated body 30 was produced like the case of 1. FIG.

  Subsequently, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 17N. Further, in the same manner as in Example 1, the heat resistance and vapor permeability of the bag 10 produced using the laminate 30 were evaluated. As a result, both evaluation results of heat resistance and steamability were good.

Example 4
Example except that PBT constituting the first base material 41 of Example 2 was used as the second base material 51 and PET constituting the second base material 51 of Example 2 was used as the first base material 41 The laminated body 30 was produced like the case of 1. FIG.

  Subsequently, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 17N. Further, in the same manner as in Example 1, the heat resistance and vapor permeability of the bag 10 produced using the laminate 30 were evaluated. As a result, both evaluation results of heat resistance and steamability were good.

(Comparative Example 1)
The laminated body 30 was produced like the case of Example 1 except having used the base material containing 100 mass% PET as the 1st base material 41 of the 1st film 40. FIG. The thickness of the first base material 41 was 12 μm.

  Subsequently, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 12N. Further, in the same manner as in Example 1, the heat resistance and vapor permeability of the bag 10 produced using the laminate 30 were evaluated. As a result, both evaluation results of heat resistance and steamability were good.

(Comparative Example 2)
The laminated body 30 was produced like the case of the comparative example 1 except having used the 15-micrometer-thick nylon film (Konjin Holdings Co., Ltd. Bonile W) as the 2nd base material 51 of the 2nd film 50. .

  Subsequently, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 17N. Further, in the same manner as in Example 1, the heat resistance and vapor permeability of the bag 10 produced using the laminate 30 were evaluated. As a result, holes were formed in the laminate 30. Moreover, the steam vent seal part of the steam vent mechanism could not be peeled off. That is, both evaluation results of heat resistance and steamability were bad.

  The layer structure and evaluation result of the laminated body of Examples 1-4 and Comparative Examples 1 and 2 are collectively shown in FIG. In FIG. 6, in the “layer configuration” column, the components of the laminate excluding the adhesive layer are described from the top in order from the outer surface side layer. As can be seen from the comparison between Examples 1 to 4 and Comparative Example 1, when the first base material 41 or the second base material 51 contains PBT, both the first base material 41 and the second base material 51 are made of PET. Compared to the case of inclusion, a high piercing strength could be realized. Moreover, as can be seen from the comparison between Examples 1 to 4 and Comparative Example 2, the second substrate 51 contains nylon by using a material other than nylon, specifically PBT or PET, as the second substrate 51. Compared to the case, it was possible to achieve better heat resistance and steamability.

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 Steam release mechanism 20a Steam release seal part 20b Non-seal part 30 Laminate 40 First film 41 First substrate 41a Layer 42 Print layer 45 First adhesive layer 50 Second film 51 Second substrate 55 Second adhesive layer 60 Third film 61 Sealant layer 70 Needle

Claims (10)

A bag having a steam release mechanism,
The laminate constituting the bag includes at least a first base material, a second base material, and a sealant layer in this order,
Of the first base material and the second base material, one includes polyethylene terephthalate, and the other includes 51% by mass or more of polybutylene terephthalate,
Of the first base material and the second base material, the base material containing polybutylene terephthalate has a multilayer structure part including 10 layers or more, or has a single-layer structure, and is polybutylene terephthalate. The IV value of the bag is 1.10 dl / g or more and 1.35 dl / g or less.   The bag according to claim 1, wherein the puncture strength of the laminate is 13N or more.   The laminate includes a transparent vapor deposition layer provided on the first base material or the second base material between the first base material and the second base material, and a transparent material provided on the transparent vapor deposition layer. The bag according to claim 1, further comprising a gas barrier coating film. The transparent vapor deposition layer includes aluminum oxide,
The bag according to claim 3, wherein a covalent bond of an aluminum atom and a carbon atom is formed at an interface between the first base material or the second base material and the transparent vapor deposition layer.   The said laminated body is a bag as described in any one of Claims 1 thru | or 4 further including the printing layer located between the said 1st base material and the said 2nd base material. The first substrate comprises polyethylene terephthalate;
The bag according to any one of claims 1 to 5, wherein the second base material contains polybutylene terephthalate. The first substrate comprises polybutylene terephthalate;
The bag according to any one of claims 1 to 5, wherein the second base material includes polyethylene terephthalate.   The bag according to any one of claims 1 to 7, wherein the sealant layer contains 90% by mass or more of polypropylene.   The laminate according to claim 1, further comprising a first adhesive layer located between the first base material and the second base material and including a cured product of a polyol and an aliphatic isocyanate compound. The bag according to any one of the above.   The said laminated body is located between the said 2nd base material and the said sealant layer, The 2nd adhesive bond layer containing the hardened | cured material of a polyol and an aliphatic isocyanate compound is further provided in any one of Claim 1 thru | or 9. The bag according to one item.