JP2018058356A - Laminate and bag composed of the laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel laminate that is a laminate of two films and has excellent impact resistance.SOLUTION: A laminate comprises a base material/an adhesive layer/a sealant layer, the base material/a printed layer/the adhesive layer/the sealant layer, the base material/a transparent gas barrier layer/the printed layer/the adhesive layer/the sealant layer, or the base material/the transparent gas barrier layer/the adhesive layer/the sealant layer. The base material has 51 mass% or more of polybutylene terephthalate and the laminate has an impact strength of 800 kJ/m or more.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a laminate and a bag composed of the laminate.

  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, or semi-cooked foods cooked by heating. Heating is performed, for example, by boiling the contents together with the bag.

  The laminated body constituting the bag is required to have various properties such as heat resistance that can withstand heat treatment and impact resistance that can withstand an impact when the bag is dropped. Considering these points, for example, Patent Document 1 proposes to use a laminate including a polybutylene terephthalate layer / deposition film / adhesive layer / sealant layer in order from the outer surface side to the inner surface side. Yes. Note that “/” represents a boundary between layers. The adhesive layer is a layer for laminating two films. For example, a PBT film that constitutes a polybutylene terephthalate (hereinafter also referred to as PBT) layer and is provided with a vapor deposition film, and a sealant film that constitutes a sealant layer are laminated by a dry laminating method via an adhesive layer. Yes.

JP 2014-15233 A

  As described above, the laminated body described in the cited document 1 has a two-layer structure including two films of a base material layer and a sealant layer. When the laminated body has a two-layer structure, there is a problem that the bag easily breaks when dropped.

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

The present invention is a laminate,
Substrate / adhesive layer / sealant layer,
Substrate / printing layer / adhesive layer / sealant layer,
A substrate / transparent gas barrier layer / printing layer / adhesive layer / sealant layer, or a substrate / transparent gas barrier layer / adhesive layer / sealant layer,
The base material contains 51% by mass or more of polybutylene terephthalate,
The laminated body has an impact strength of 800 kJ / m or more.

  In the laminate according to the present invention, the base material may contain 60% by mass or more of polybutylene terephthalate.

  In the laminate according to the present invention, the puncture strength of the laminate is preferably 11 N or more.

  In the laminate according to the present invention, the sealant layer may include 90% by mass or more of polypropylene. The sealant layer may include a propylene / ethylene block copolymer.

  In the laminate according to the present invention, the sealant layer may include polyethylene having a melting point of 100 ° C. or higher.

  In the laminate according to the present invention, the adhesive layer is a cured product of a polyol and an aliphatic isocyanate compound, and the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol is 3.5 or more. May be.

  In the laminate according to the present invention, the base material may have a multilayer structure including 10 layers or more. Alternatively, the substrate may have a single layer structure having an IV value of 1.10 dl / g or more and 1.35 dl / g or less.

  In the laminate according to the present invention, the sealant layer may include a thermoplastic elastomer.

The present invention is a bag,
A laminate comprising an outer surface and an inner surface;
A seal portion that joins the inner surfaces of the laminate, and
The laminate is composed of a base material / adhesive layer / sealant layer in order from the outer surface side to the inner surface side.
Substrate / printing layer / adhesive layer / sealant layer,
A substrate / transparent gas barrier layer / printing layer / adhesive layer / sealant layer, or a substrate / transparent gas barrier layer / adhesive layer / sealant layer,
The base material contains 51% by mass or more of polybutylene terephthalate,
It is a bag whose impact strength of the said laminated body is 800 kJ / m or more.

  ADVANTAGE OF THE INVENTION According to this invention, it is a laminated body by which two films were laminated | stacked, Comprising: The laminated body which has the outstanding impact resistance can be provided.

It is a front view which shows the bag in embodiment of this invention. It is an exploded view which shows the film which comprises the bag shown in FIG. 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 sectional drawing which shows the other example of the layer structure 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 front view which shows the bag in one modification of embodiment of this invention. It is a top view which shows the test piece for evaluating impact strength. It is sectional drawing of the test piece shown in FIG. It is a figure which shows an example of the measuring method of impact strength. It is a figure which shows an example of the measuring method of piercing strength. It is a figure which shows the evaluation result of Examples 1-5 and Comparative Examples 1-3.

  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. FIG. 2 is an exploded view showing a film constituting the bag shown in FIG. The bag 10 includes a storage portion 17 that stores the contents. In addition, in FIG. 1, the bag 10 of the state in which the contents are not accommodated is shown. Bag 10 by this embodiment is constituted so that retort processing can be performed. 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 FIGS. 1 and 2, the bag 10 includes a surface film 14 that constitutes the 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 front 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 has an outer edge seal portion that extends along the outer edge of the bag 10. 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 filled (a state in which the contents are not filled), 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 and the upper seal portion described later 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.

Easy opening means The front film 14 and the back film 15 may be provided with easy opening means 25 for tearing the front film 14 and the back film 15 to open the bag 10. For example, as shown in FIG. 1, the easy-opening means 25 may include a notch 26 that is formed in the side seal portion 13 a of the bag 10 and serves as a starting point of tearing. Further, a half-cut line formed by laser processing, a cutter, or the like may be provided as the easy-opening means 25 in a portion that becomes a path when the bag 10 is torn.

  Moreover, although not shown, the easy-opening means 25 may include notches and scars formed in the area where the seal portion is formed in the front film 14 and the back film 15. The scar group may include, for example, a plurality of through holes formed so as to penetrate the front film 14 and / or the back film 15. Alternatively, the scar group may include a plurality of holes formed on the outer surface of the front film 14 and / or the back film 15 so as not to penetrate the front film 14 and / or the back film 15.

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 a first film 40 and a second film 50 laminated on the first film 40 via an adhesive layer 60. The first film 40 is located on the outer surface 30y side, and the second film 50 is located on the inner surface 30x side opposite to the outer surface 30y. The inner surface 30x is a surface facing the accommodating portion 17 side in the bag 10 constituted by the laminate 30, and the outer surface 30y is a surface located on the opposite side of the inner surface 30x.

The first film 40 includes at least a base material 41. The first film 40 may further include a print layer 42 provided on the inner surface 30x side of the base material 41. The second film 50 includes a sealant layer 51. Therefore, it can be said that the laminated body 30 by this Embodiment is equipped with the base material / printing layer / adhesive layer / sealant layer in order from the outer surface side to the inner surface side. Note that “/” represents a boundary between layers.

  Hereinafter, each of the first film 40, the second film 50, and the adhesive layer 60 will be described in detail.

(First film)
The first film 40 includes at least a base material 41 constituting the outer surface 30y of the laminate 30. As shown in FIG. 3, the first film 40 may further include a printing layer 42 provided on the inner surface 30 x side of the base material 41.

〔Base material〕
The base material 41 includes polybutylene terephthalate (hereinafter also referred to as PBT) as a main component. For example, the base material 41 includes 51% by mass or more of PBT. Hereinafter, the advantage that the base material 41 includes 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 base material 41 containing PBT similarly to the case of polyethylene terephthalate (hereinafter also referred to as PET).

  Moreover, PBT is excellent in heat resistance. For this reason, it is possible to prevent the base material 41 from being deformed or the strength of the base material 41 from being lowered when the bag 10 is subjected to boil processing or retort processing. 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.

  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, even if it is a case where the base material 41 containing PBT is arrange | positioned on the outer surface 30y of the laminated body 30, it suppresses that the base material 41 absorbs a water | moisture content and the laminate strength of the laminated body 30 falls. Can do.

  Hereinafter, the configuration of the base material 41 including PBT will be described in detail. As the configuration of the base material 41 including PBT in the present embodiment, any of the following first configuration or second configuration may be adopted.

[First Configuration of Substrate]
The content of PBT in the 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, particularly preferably 75% by mass or more, and most preferably. 80% by 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 base material 41 may contain a polyester resin other than PBT. Thereby, for example, the film formability when the film-like substrate 41 is biaxially stretched and the mechanical properties of the substrate 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 base material 41 may contain, as an additive, a polyester-based and polyamide-based elastomer obtained by copolymerizing at least one of a flexible polyether component, a polycarbonate component, and a polyester component. 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 addition amount of the additive exceeds 20% by mass, the effect as the additive may be saturated, or the transparency of the base material 41 may be reduced.

  An example of a method for producing the film-like base material 41 according to the first configuration will be described. Here, a method for producing the film-like 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 base material 41 is produced by casting the resin in multiple layers, as shown in FIG. 4, the base material 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, a method of laminating thermoplastic resins sent from different flow paths using two or more extruders in multiple layers 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 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 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.
The thickness of the base material 41 is preferably 9 μm or more, and more preferably 12 μm or more. Moreover, the thickness of the base material 41 is preferably 25 μm or less, more preferably 20 μm or less. By setting the thickness of the base material 41 to 9 μm or more, the base material 41 has sufficient strength. Moreover, the base material 41 comes to show the moldability which was excellent by making the thickness of the base material 41 into 25 micrometers or less. For this reason, the process which processes the laminated body 30 containing the base material 41 and manufactures the bag 10 can be implemented efficiently.

[Second Configuration of Base Material]
The base material 41 according to the second configuration is made of a single layer film containing polyester having butylene terephthalate as a main repeating unit. For example, the 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, and condenses them. Homo- or copolymer-type polyester obtained. The content of PBT in the 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, further preferably 80% by mass or more, and most preferably. Is 90% by mass or more. Moreover, it is preferable that the 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 substrate 41, PBT having a melting point of 200 ° C. or more and 250 ° C. or less and an IV value (intrinsic viscosity) of 1.10 dl / g or more and 1.35 dl / g or less Is 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 whole material constituting the base material 41. The IV value can be calculated based on JIS K 7367-5: 2000.

The base material 41 which concerns on a 2nd structure may contain polyester resins other than PBT, such as PET, in 30 mass% or less. When the base material 41 contains PET in addition to PBT, PBT crystallization can be suppressed, and the stretchability of the PBT film can be improved. As PET mix | blended with PBT of the base material 41, the polyester which uses ethylene terephthalate as a 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 base material 41 is 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, a crystallization accelerator, if necessary. Etc. may be contained. Further, the polyester resin pellets used as the raw material of the substrate 41 has a moisture content of 0.05% by weight or less, preferably 0.01% by weight or less 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 that

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

  In order to stably produce the film of the base material 41 having the above-described configuration, it is important to suppress the crystal growth in the unstretched raw fabric. 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 base material 41 produced as described above is constituted by a single layer containing, for example, polyester having butylene terephthalate as a main repeating unit. 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.

(Print layer)
The printed layer 42 is a layer printed on the 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.

  The ink constituting the printing layer 42 includes a binder and a pigment. The binder includes, for example, polyurethane as in the adhesive layer 60 described later. Polyurethane is a cured product produced by a reaction between a polyol as a main agent and an isocyanate compound as a curing agent. Details of the polyol and the isocyanate compound will be described in the paragraph of the adhesive layer 60.

  The pigment of the printing layer 42 is a colored powder and exists in the binder with a predetermined distribution density. The color exhibited by the pigment is not particularly limited, and various pigments such as red, blue, green, white, and black can be used. For example, the average particle diameter of the pigment may be 0.1 μm or more and 1 μm or less, or 0.5 μm or more and 1 μm or less. White pigments generally have larger dimensions than other color pigments. For example, the average particle diameter of the white pigment is 0.5 μm or more and 1 μm or less. The average particle diameter of the pigment can be measured by a dynamic light scattering method.

  The printing layer 42 may be composed of a single layer or may include a plurality of layers. For example, the printing layer 42 may include a first layer that includes a pigment that exhibits a first color, and a second layer that includes a pigment that exhibits a second color different from the first color. . The thickness of one layer of the printing layer 42 is, for example, not less than 0.5 μm and not more than 3 μm.

[Gas barrier layer]
FIG. 5 is a cross-sectional view illustrating another example of the layer configuration of the stacked body 30. As shown in FIG. 5, the 1st film 40 of the laminated body 30 is located in the inner surface 30x side of the base material 41, and may further contain the transparent gas barrier layer 43 which has transparency. In this case, the printing layer 42 is located on the inner surface 30 x side of the transparent gas barrier layer 43. It can be said that the laminated body 30 in the example shown in FIG. 5 includes a base material / transparent gas barrier layer / printing layer / adhesive layer / sealant layer in order from the outer surface side to the inner surface side.

Hereinafter, the transparent gas barrier layer 43 will be described. The transparent gas barrier layer 43 is formed on the surface on the inner surface 30x side of the base material 41 and includes at least a transparent vapor deposition layer 43a made of an inorganic material having transparency. The transparent gas barrier layer 43 may further include a transparent gas barrier coating film 43b that is formed on the surface on the inner surface 30x side of the transparent vapor deposition layer 43a and has transparency. In this case, it can be said that the laminated body 30 is provided with a base material / transparent deposition layer / transparent gas barrier coating film / printing layer / adhesive layer / sealant layer in order from the outer surface side to the inner surface side.

  The transparent vapor deposition layer 43a functions as a layer having a gas barrier function that prevents permeation of oxygen gas, water vapor, and the like. Two or more transparent vapor deposition layers 43a may be provided. When it has two or more transparent vapor deposition layers 43a, each may have the same composition or different compositions. Examples of the method for forming the transparent vapor deposition layer 43a include physical vapor deposition (Physical Vapor Deposition, PVD) such as vacuum deposition, sputtering, and ion plating, or plasma chemical vapor deposition, 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 43a is formed of an inorganic material having transparency, such as aluminum oxide (aluminum oxide) and silicon oxide. As the transparent vapor deposition layer 43a, it is preferable to use an amorphous thin film of aluminum oxide. Specifically, the transparent vapor-deposited layer 43a is an amorphous thin film of aluminum oxide represented by the formula AlO _X (wherein X represents a number in the range of 0.5 to 1.5). . As the transparent vapor-deposited layer 43a, 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 AlO _X (where X represents a number in the range of 0.5 to 1.5), and in the depth direction from the thin film surface toward the inner surface. It is preferable that the value of X is increasing. 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 the state which Al was 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 conducting an elemental analysis of the transparent vapor-deposited layer 43a using an analysis method such as ion etching.

  The transparent vapor deposition layer 43a 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-deposited layer 43a uses an X-ray photoelectron spectrometer (measuring conditions: X-ray source AlKα, X-ray output 120W) 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 43 a and the base material 41. For example, when the transparent vapor deposition layer 43a contains aluminum oxide, the covalent bond of an aluminum atom and a carbon atom shall be formed in the interface of the base material 41 and the transparent vapor deposition layer 43a. The covalent bond can be detected by measurement by X-ray photoelectron spectroscopy (hereinafter referred to as “XPS measurement” for short).

  Moreover, in the transparent vapor deposition layer 43a, all the bonds including the carbon atom observed when the ratio of the covalent bond between the aluminum atom and the carbon atom is measured when the interface between the transparent vapor deposition layer 43a and the substrate 41 is measured by XPS measurement. It is preferable that it is within the range of 0.3% or more and 30% or less. Thereby, the adhesiveness of the transparent vapor deposition layer 43a and the base material 41 is strengthened, transparency is excellent, and the thing of the performance with a good balance is obtained as a gas barrier property vapor deposition film.

  If the 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 43a is not sufficiently improved, and it becomes difficult to stably maintain the barrier property.

Further, the transparent vapor deposition layer 43a mainly composed of aluminum oxide has an AL (aluminum) / O (oxygen) ratio of transparent vapor deposition on the opposite side of the base material 41 from the interface between the base material 41 and the transparent vapor deposition layer 43a. It is preferably 1.0 or less in the range up to 3 nm toward the surface of the layer 43a.
When the AL / O ratio exceeds 1.0 within the range from the interface between the transparent vapor deposition layer 43a and the base material 41 toward the surface of the transparent vapor deposition layer 43a opposite to the base material 41, Adhesiveness with the transparent vapor deposition layer 43a becomes insufficient, the proportion of aluminum increases, and the transparency of the transparent vapor deposition layer 43a decreases.

  The thickness of the transparent vapor deposition layer 43a is, for example, 30 mm or more and 150 mm or less. If it is less than 30 mm, the gas barrier property may be insufficient even when the transparent gas barrier coating film 43b 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-deposited layer 43a exceeds 150 mm, the flexibility of the laminate 30 is lowered, and when the laminate 30 is used for the bag 10, a part of the transparent vapor-deposited layer 43a is not cracked. It is considered that pinholes are generated and gas barrier properties are lowered. The thickness of the transparent vapor deposition layer 43a is preferably 40 mm or more and 130 mm or less, more preferably 50 mm or more and 120 mm or less. In addition, the thickness of the transparent vapor deposition layer 43a 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 43a, it can carry out by the method of changing the deposition rate of the transparent vapor deposition layer 43a, the method of changing the vapor deposition rate, etc.

  In the case where the transparent vapor deposition layer 43a is formed on the inner surface 30x side of the base material 41, the surface of the base material 41 on the inner surface 30x side may be subjected to pretreatment such as corona discharge treatment, frame processing, and plasma processing in advance. Good. 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 43a and the base material 41, the surface of the base material 41 on which the transparent vapor deposition layer 43a is to be formed is pretreated. It is preferable. When the pretreatment is plasma treatment, plasma is supplied to the surface of the base material 41 in a reduced pressure environment of 0.1 Pa or more and 100 Pa or less by the pretreatment apparatus. 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 pretreatment, the plasma can be confined in the vicinity of the surface of the substrate 41. Thereby, the shape of the surface of the base material 41, a chemical bonding state, and a functional group can be changed, and the chemical properties of the surface of the base material 41 can be changed. This makes it possible to improve the adhesion between the base material 41 and the transparent vapor deposition layer 43a.

The transparent gas barrier coating film 43b 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 43b 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.

(Second film)
The second film 50 includes at least a sealant layer 51 that constitutes the inner surface 30 x of the laminate 30. As a material constituting the sealant layer 51, one or more resins selected from polyethylene such as low density polyethylene and linear low density polyethylene, and polypropylene can be used. The sealant layer 51 may be a single layer or a multilayer. The sealant layer 51 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, the sealant layer 51 has a heat resistance that can withstand the processing at these high temperatures.

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

  When considering from the viewpoint of retort processing, a material mainly composed of propylene can be used as a material constituting the sealant layer 51. 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 51 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 51 includes a propylene / ethylene block copolymer. For example, the second film 50 including the sealant layer 51 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 laminate 30 including the second film 50 can be increased, thereby suppressing the bag 10 from being broken by the impact at the time of dropping. can do. Moreover, the puncture resistance of the laminated body 30 can be improved.

  The sealant layer 51 may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the second film 50 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 layer 51 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 51 is preferably 30 μm or more, more preferably 40 μm or more. Further, the thickness of the sealant layer 51 is preferably 100 μm or less, and more preferably 80 μm or less.

(Adhesive layer)
The adhesive layer 60 includes an adhesive for bonding the first film 40 and the second film 50. The adhesive constituting the adhesive layer 60 is generated from an adhesive composition prepared by mixing a first composition containing a main agent and a solvent and a second composition containing a 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 an ether-based two-component reactive adhesive or an ester-based two-component reactive adhesive. 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. 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.

  As an isocyanate compound which reacts with polyols, such as polyether polyol and polyester polyol, and produces | generates hardened | cured material, an aromatic isocyanate compound and an aliphatic isocyanate compound exist. Of these, the aromatic isocyanate compound elutes components that cannot be used in food applications in a high temperature environment such as during heat sterilization (retort treatment). By the way, as shown in FIGS. 3 and 5, the adhesive layer 60 is in contact with the second film 50 constituting the inner surface 30 x of the laminate 30. For this reason, when the adhesive layer 60 contains an aromatic isocyanate compound, a component eluted from the aromatic isocyanate compound may adhere to the contents of the bag 10 constituted by the laminate 30.

  In consideration of such a problem, 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 as an adhesive constituting the adhesive layer 60. Thereby, it can prevent that the component which cannot be used for the food use resulting from the adhesive bond layer 60 adheres to the content. Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI).

  As shown in Examples described later, impact resistance can be increased by increasing the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxy group of the polyol. For example, the molar ratio of the curing agent (aliphatic isocyanate compound) to the hydroxy group of the main agent (polyol) is conventionally about 3. In the present embodiment, the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol is preferably 3.5 or more, more preferably 4 or more, and 4.5 or more. Is more preferable. More preferably, the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol is greater than 5.

  On the other hand, an aliphatic isocyanate compound is expensive, and increasing the amount of the aliphatic isocyanate compound is not preferable in terms of production cost. Further, as the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol increases, the temperature necessary for curing the adhesive composition increases or the time increases. Considering these points, the molar ratio of the aliphatic isocyanate group to the hydroxy group is preferably 7 or less, and more preferably 6 or less.

The adhesive layer 60 is obtained by applying the adhesive composition to the first film 40 or the second film 50, then drying the adhesive composition, and reacting the main agent and the solvent in the adhesive composition. The adhesive composition is formed by curing. In this embodiment, the adhesive composition after drying, the weight per unit area, for example, preferably to 2 g / ^{m 2} or more and a 5 g / ^{m 2} or less, 3 g / ^{m 2} or more and 4g / ^{m 2} More preferably, it is as follows. The thickness of the adhesive layer 60 is preferably 2 μm or more and 5 μm or less, and more preferably 3 μm or more and 4 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. Subsequently, the film-like base material 41 is produced by extruding a resin material by a melt extrusion method such as a cast method or a tubular method. Subsequently, an inorganic material such as aluminum oxide may be vapor-deposited on the film-like substrate 41 to form the transparent vapor-deposited layer 43a. Subsequently, a transparent gas barrier coating composition 43b may be formed by applying a transparent gas barrier composition on the transparent vapor deposition layer 43a. Thereafter, the printing layer 42 is formed on the substrate 41 or the transparent gas barrier coating film 43b. Thus, the 1st film 40 provided with the base material 41 and the printing layer 42, or the base material 41, the transparent gas barrier layer 43 containing the transparent vapor deposition layer 43a and the transparent gas barrier coating film 43b, and the printing layer 42. The 1st film 40 provided with these can be obtained.

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

  First, the 1st composition containing a main ingredient and a solvent and the 2nd composition containing a hardening | curing agent and a solvent are mixed, and an adhesive composition is produced. Subsequently, the adhesive composition is applied to the first film 40 or the second film 50. For example, it is applied on the printing layer 42 of the first film 40. Subsequently, the applied adhesive composition is dried to volatilize the solvent. Then, the 1st film 40 and the 2nd film 50 are laminated | stacked through the adhesive composition after drying. Then, a laminated body is heated over 24 hours or more, for example in the environment of 20 degreeC or more. Thereby, an adhesive composition is hardened and the adhesive agent containing the hardened | cured material of a polyol and an aliphatic isocyanate compound is obtained. Thus, the laminated body 30 provided with the 1st film 40 and the 2nd film 50 can be obtained.

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. Thereafter, the upper part 11 is heat-sealed to form the upper seal part 11a. In this way, as shown in FIG. 6, the bag 10 in which the contents 18 are accommodated and sealed can be obtained.

(Effect of this embodiment)
According to this Embodiment, when the laminated body 30 which comprises the surface film 14 and the back surface film 15 contains the base material 41 which has PBT as a main component, there can exist the following effect.
First, PBT is excellent in printability. For this reason, the printing layer 42 can be provided on the base material 41 containing PBT similarly to the case of polyethylene terephthalate (hereinafter also referred to as PET).
Moreover, PBT is excellent in heat resistance. For this reason, it is possible to prevent the base material 41 from being deformed or the strength of the base material 41 from being lowered when the bag 10 is subjected to boil processing or retort processing.
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. The puncture strength of the laminated body constituting the bag 10 is preferably 11N or more, more preferably 13N or more, and further preferably 15N or more. A method for measuring the piercing strength will be described in Example 1 described later.
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 base material 41 containing PBT is arrange | positioned on the outer surface 30y of the laminated body 30, it suppresses that the base material 41 absorbs a water | moisture content and the laminate strength of the laminated body 30 falls. Can do.

  In the present embodiment, the sealant layer 51 of the second film 50 includes a propylene / ethylene block copolymer. For this reason, the impact resistance of the laminated body 30 including the second film 50 and the second film 50 can be enhanced. Therefore, even when the bag 10 is configured using the laminate 30 having a two-layer structure, the bag 10 can be prevented from breaking due to an impact such as dropping.

  Moreover, in this Embodiment, the adhesive bond layer 60 for joining the 1st film 40 and the 2nd film 50 contains many hardening | curing agents compared with the past. For example, the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol in the adhesive layer 60 is 3.5 or more. For this reason, the impact resistance of the laminate 30 having a two-layer structure including the first film 40 and the second film 50 can be increased. Therefore, even when the bag 10 is configured using the laminate 30 having the two-layer structure, it is possible to suppress the bag 10 from being broken due to an impact such as dropping.

  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.

(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, as shown in FIG. 7, the bag 10 is a so-called four-sided seal formed by joining the inner surfaces of the surface film 14 and the back film 15 made of the laminate 30 at the upper part 11, the lower part 12, and the side part 13. It may be a bag.

Moreover, in the above-mentioned embodiment, the example in which the first film 40 of the laminated body 30 constituting the bag 10 has the printed layer 42 in addition to the base material 41 has been shown. However, the present invention is not limited to this, and the first film 40 may not have the printing layer 42. Therefore, the following arrangement is possible in order from the outer surface side to the inner surface side as the layer configuration of the laminate 30.
Base material / adhesive layer / sealant layer Base material / transparent gas barrier layer / adhesive layer / sealant layer

  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
(Production of laminate)
A film-like 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 base material 41 was 15 μm. Subsequently, the printing layer 42 was formed on the film-like substrate 41 by gravure printing. As an ink for forming the printing layer 42, white ink ceramic FB manufactured by Dainichi Seika Kogyo was used. Thus, the 1st film 40 which has the base material 41 and the printing layer 42 was produced. The thickness of the printing layer 42 was 1 μm.

  Next, the 1st composition containing a main ingredient and a solvent and the 2nd composition containing a hardening | curing agent and a solvent were mixed, and the adhesive composition was produced. RU-40 made by Rock Paint Co., Ltd. was used as the first composition containing the main agent and the solvent. RU-40 contains a polyester polyol. As a 2nd composition containing a hardening | curing agent and a solvent, Rock Paint Co., Ltd. H-4 was used. H-4 contains an aliphatic isocyanate compound. The weight ratio of the second composition to the first composition was 0.15. Moreover, the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxy group of the polyol in the adhesive composition was 4.5.

  Next, the adhesive composition was applied on the printing layer 42 of the first film 40. Subsequently, the adhesive composition applied on the first film 40 was dried to volatilize the solvent. Then, the 1st film 40 and the 2nd film 50 were laminated | stacked through the adhesive composition after drying. Subsequently, the laminate was heated in an environment of 40 ° C. for 96 hours. Thereby, the adhesive composition was cured to obtain an adhesive layer 60 containing a cured product of a polyol and an aliphatic isocyanate compound. The thickness of the adhesive layer 60 was 3 μm.

  Next, the second film 50 including the sealant layer 51 was prepared. As the sealant layer 51, an unstretched polypropylene film ZK93FM manufactured by Toray Film Processing Co., Ltd. was used. The thickness of the sealant layer 51 was 70 μm.

[Evaluation of impact resistance]
Subsequently, the two laminates 30 were stacked and heated at 190 ° C. for 1 second, and the inner surfaces 30x of the laminate 30 were heat-sealed. Next, the heat-sealed two laminated bodies 30 were cut out with a width of 15 mm, and the test piece 90 was produced. FIG. 8 is a plan view showing the test piece 90, and FIG. 9 is a cross-sectional view of the test piece 90 of FIG. The test piece 90 has a width W3 of 15 mm and a length W4 of 50 mm, a seal portion 91 is formed over a length W5 of 10 mm from one end, and a length of 40 mm from the other end. The seal portion is not formed. Subsequently, as shown in FIG. 14, the unsealed portion of one laminate 30 and the unsealed portion of the other laminate 30 are opposite to each other in a direction perpendicular to the surface direction of the seal portion 91. In other words, the end portion of the unsealed portion of one laminated body 30 and the end portion of the unsealed portion of the other laminated body 30 are respectively connected to the jig 92. , 93. At this time, the distance T between the jigs 92 and 93 in the direction orthogonal to the surface direction of the seal portion 91 was 40 mm. Subsequently, the impact when the one laminated body 30 and the other laminated body 30 are separated by hitting one jig 92 with the hammer 94 from the surface of the one laminated body 30 on the first film 40 side. The strength was measured. Evaluation was performed using a digital impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd. As a hammer for applying an impact to the test piece 90, a 2J hammer was used. As a result, the impact strength was 1056 kJ / m.

  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. 11, a semicircular needle 100 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 stress until the needle 100 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 15N.

(Evaluation of drop strength)
Subsequently, the two laminates 30 are stacked and heated at 190 ° C. for 1 second to heat-seal the inner surfaces 30x of the laminate 30 and are filled with 200 g of water as the contents 18, as shown in FIG. A four-side sealed bag 10 was produced. The height S1 of the bag 10 was 180 mm, and the width S2 was 130 mm.

  After storing the bag 10 containing water overnight in an environment of 3 ° C., the bag 10 holding the front film 14 and the back film 15 so as to be horizontal is dropped from a height of 120 cm, It was inspected whether the bag 10 was broken. The bag 10 was repeatedly dropped 5 times, but no broken bag was seen.

(Example 2)
A laminate 30 was produced in the same manner as in Example 1 except that the weight ratio of the second composition to the first composition was 0.2 when producing the adhesive composition. The molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxy group of the polyol in the adhesive composition was 6.

  Further, in the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 1137 kJ / m. Further, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 15N. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. The bag 10 was repeatedly dropped 5 times, but no broken bag was seen.

(Example 3)
A laminate 30 was produced in the same manner as in Example 1 except that the base material 41 having a PBT content of 70% in each layer 41a was used. Further, in the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 912 kJ / m. Further, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 13N. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. The bag 10 was repeatedly dropped 5 times, but no broken bag was seen.

(Comparative Example 1)
A laminate 30 was produced in the same manner as in Example 1 except that the weight ratio of the second composition to the first composition was 0.1 when producing the adhesive composition. The molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol in the adhesive composition was 3.

  Further, in the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 758 kJ / m. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. As a result, the bag 10 was broken by the fourth drop.

Example 4
The laminated body 30 provided with the base material 41 / adhesive layer 60 / sealant layer 51 in order from the outer surface side to the inner surface side was produced. As the base material 41, as in the case of Example 1, a film-like base material 41 including a plurality of layers 41a and manufactured by a casting method was used. As in the case of Example 1, the adhesive composition for constituting the adhesive layer 60 was constituted by the first composition containing RU-40 and the second composition containing H-4. Was used. The weight ratio of the second composition to the first composition was 0.10 as in the case of Comparative Example 1. The molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol in the adhesive composition was 3. As the sealant layer 51, an unstretched polypropylene film ZK500 manufactured by Toray Film Processing Co., Ltd. was used. ZK500 contains the above-mentioned propylene / ethylene block copolymer and elastomer. The thickness of the sealant layer 51 was 70 μm.
It can be said that the laminated body 30 of Example 4 is obtained by deleting the printing layer 42 from the laminated body 30 of Comparative Example 1 and replacing the sealant layer 51 with ZK500.

  In the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 946 kJ / m. Further, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 15N. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. The bag 10 was repeatedly dropped 5 times, but no broken bag was seen.

(Example 5)
A laminate 30 was produced in the same manner as in Example 4 except that a film-like substrate 41 containing PBT and produced by a tubular method was used as the substrate 41. The base material 41 was a single layer film composed only of PBT and an additive, and the thickness of the base material 41 was 15 μm.

  In the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 838 kJ / m. Further, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 15N. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. The bag 10 was repeatedly dropped 5 times, but no broken bag was seen.

(Comparative Example 2)
A laminate 30 was produced in the same manner as in Example 5 except that an unstretched polypropylene film ZK93FM manufactured by Toray Film Processing Co., Ltd. was used as the sealant layer 51. The thickness of the sealant layer 51 was 70 μm.

  In the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 502 kJ / m. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. As a result, the bag 10 was broken by the fourth drop.

(Comparative Example 3)
A laminate 30 was produced in the same manner as in Comparative Example 2 except that Toyobo PET film E5100 (thickness 12 μm) was used as the base material 41. Further, in the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 537 kJ / m. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. As a result, the bag 10 was broken by the fourth drop.

  In the same manner as in Example 1, the inner surfaces 30x of the two laminates 30 were heat sealed to produce a test piece 90, and the impact strength was measured. As a result, the impact strength was 502 kJ / m. Further, the drop strength of the bag 10 configured using the laminate 30 was evaluated in the same manner as in Example 1. As a result, the bag 10 was broken by the fourth drop. Further, the puncture strength of the laminate 30 was measured in the same manner as in Example 1. As a result, the piercing strength was 10N.

  The layer structure and evaluation result of the laminated body 30 of Examples 1-5 and Comparative Examples 1-3 are collectively shown in FIG. As can be seen from the comparison between Examples 1 to 5 and Comparative Examples 1 to 3, by forming the bag 10 using the laminated body 30 having an impact strength of 800 kJ / m or more, it is not broken even when dropped five times. It was possible to give the bag 10 the drop strength.

  As can be seen from the comparison between Examples 4 and 5 and Comparative Examples 1 and 2, in order to increase the impact strength of the laminate 30, the sealant layer 61 contains a propylene / ethylene block copolymer or contains an elastomer. Can be said to be preferable. Further, as can be seen from the comparison between Examples 1 and 2 and Comparative Example 1, in increasing the impact strength of the laminate 30, in the adhesive composition, the isocyanate group of the aliphatic isocyanate compound relative to the hydroxyl group of the polyol in the adhesive composition. It can be said that a high molar ratio is preferable.

  As shown in Comparative Example 3, when the substrate 41 was made of a PET film, the puncture strength of the laminate 30 was 10 N or less. On the other hand, as shown in Examples 1 to 5, when the base material 41 is made of a film containing PBT as a main component, the puncture strength of the laminate 30 can be made 11N or more, more specifically 13N or more. We were able to.

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 25 Easy-opening means 26 Notch 30 Laminate 40 First Film 41 Base material 41a Layer 42 Print layer 43 Transparent gas barrier layer 43a Transparent vapor deposition layer 43b Transparent gas barrier coating film 50 Second film 51 Sealant layer 60 Adhesive layer

Claims (11)

A laminate,
Substrate / adhesive layer / sealant layer,
Substrate / printing layer / adhesive layer / sealant layer,
A substrate / transparent gas barrier layer / printing layer / adhesive layer / sealant layer, or a substrate / transparent gas barrier layer / adhesive layer / sealant layer,
The base material contains 51% by mass or more of polybutylene terephthalate,
A laminate having an impact strength of 800 kJ / m or more.   The laminate according to claim 1, wherein the base material contains 60% by mass or more of polybutylene terephthalate.   The laminated body of Claim 1 or 2 whose puncture intensity | strength of the said laminated body is 11 N or more.   The laminate according to any one of claims 1 to 3, wherein the sealant layer contains 90% by mass or more of polypropylene.   The laminate according to claim 4, wherein the sealant layer includes a propylene / ethylene block copolymer.   The laminate according to any one of claims 1 to 3, wherein the sealant layer includes polyethylene having a melting point of 100 ° C or higher.   The adhesive layer is a cured product of a polyol and an aliphatic isocyanate compound, and the molar ratio of the isocyanate group of the aliphatic isocyanate compound to the hydroxyl group of the polyol is 3.5 or more. The laminated body as described in any one.   The laminate according to any one of claims 1 to 7, wherein the base material has a multilayer structure portion including 10 layers or more.   The said base material is a laminated body as described in any one of Claims 1 thru | or 7 which consists of a single layer structure which has IV value of 1.10 dl / g or more and 1.35 dl / g or less.   The laminate according to any one of claims 1 to 9, wherein the sealant layer includes a thermoplastic elastomer. A bag,
A laminate comprising an outer surface and an inner surface;
A seal portion that joins the inner surfaces of the laminate, and
The laminate is composed of a base material / adhesive layer / sealant layer in order from the outer surface side to the inner surface side.
Substrate / printing layer / adhesive layer / sealant layer,
A substrate / transparent gas barrier layer / printing layer / adhesive layer / sealant layer, or a substrate / transparent gas barrier layer / adhesive layer / sealant layer,
The base material contains 51% by mass or more of polybutylene terephthalate,
The bag whose impact strength of the said laminated body is 800 kJ / m or more.