Laminate, packaging bag, and package

Abstract

To provide a packaging bag and a package excellent in discharge property and handling ability during opening.SOLUTION: A laminate has a layered structure comprising a substrate layer, an intermediate layer, and a sealant layer in this order, wherein maximum opening heights H1 and H2 measured through a predetermined process satisfy the conditions of 4 mm≤H1 and 6 mm≤H2, and a loop stiffness value after heating at 128°C for 15 minutes is 80 mN or more and 220 mN or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a laminate, a packaging bag, and a package.

Background Art

[0002] Laminates are widely used mainly as packaging materials for foods, pharmaceuticals, etc. that include heat sterilization such as boiling treatment and retort treatment. As a laminate, a laminate including a biaxially stretched PET (polyethylene terephthalate) film excellent in heat resistance and toughness and a polyolefin film such as polyethylene or polypropylene as a sealant layer is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is required that the contents contained in the packaging material can be easily discharged. The conventional laminate has room for improvement in terms of dischargeability.

[0005] In addition, the packaging material is required to be excellent in handling properties at the time of opening.

[0006] One aspect of the present disclosure provides a packaging bag and a package that are excellent in dischargeability and handling properties at the time of opening. Another aspect of the present disclosure provides a laminate useful for manufacturing such a packaging bag and a package.

Means for Solving the Problems

[0007] In order to solve the above problems, the present disclosure provides the following laminate, packaging bag, and package. [1] A base material layer, An intermediate layer, A sealant layer, A laminate having a laminated structure including the following components in this order, wherein the maximum opening heights H1 and H2 measured through the following steps satisfy the following conditions, 4 mm ≤ H1 6 mm ≤ H2 wherein the maximum opening heights H1 and H2 are (1a) A step of preparing two test pieces each having a size of 90 mm in width and 140 mm in length from the laminate, (1b) A step of overlapping the two test pieces such that the sealant layers face each other and sealing three sides with a seal width of 5 mm to form a bag, (1c) A step of injecting 70 g of water from the upper end of the bag and then sealing the upper end with a seal width of 5 mm to obtain a test body, (1d) A step of heating the test body under the conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa, (1e) After the step (1d), cutting from one side portion to the other side portion of the bag at a first position 20 mm from the upper end of the bag, discharging the water, and then measuring the maximum opening height H1 at the first position with the bag placed on a horizontal table, (1f) After the step (1e), cutting from one side portion to the other side portion of the bag at a second position 50 mm from the first position, and measuring the maximum opening height H2 at the second position with the bag placed on a horizontal table, measured through the above steps, A laminate having a loop stiffness value of 80 mN or more and 220 mN or less after heating at 128°C for 15 minutes. [2] The laminate according to [1], wherein when heated at 128°C for 15 minutes, the MD heat shrinkage rate obtained by the following formula (1) is 1.0% or more and 3.0% or less, and the TD heat shrinkage rate obtained by the following formula (2) is 1.0% or more and 3.0% or less. MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100... (1) TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100... (2) [3] The laminate according to [1] or [2], wherein when heated at 128°C for 15 minutes, the sealant layer thermally expands in the MD direction and thermally contracts in the TD direction. [4] The base material layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD obtained by the following formula (1) is S1 MD and the thermal shrinkage rate of TD obtained by the following (2) is S1 TD When this is done, S1 MD and S1 TD The difference between them (S1 MD - S1 TD ) is more than 0% and 5% or less. The laminate according to any one of [1] to [3]. MD thermal shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100 …(1) TD thermal shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 …(2) [5] The intermediate layer has a second base material layer. The second base material layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD obtained by the following formula (1) is S2 MD and the thermal shrinkage rate of TD obtained by the following formula (2) is S2 TD When this is done, S2 MD and S2 TD The difference between them (S2 MD - S2 TD ) is more than 0% and 5% or less. The laminate according to any one of [1] to [4]. MD thermal shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100 …(1) TD thermal shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 …(2) [6] The laminate according to any one of [1] to [5], wherein the maximum opening heights H1 and H2 satisfy the following conditions. 4 mm ≤ H1 ≤ 7 mm 6 mm ≤ H2 ≤ 9 mm [7] The laminate according to any one of [1] to [6], wherein the base material layer, the intermediate layer, and the sealant layer contain a polypropylene-based resin, and the proportion of the total mass of the polypropylene-based resin in the laminate is 90% by mass or more. [8] A packaging bag formed using the laminate according to any one of [1] to [7]. [9] A packaging bag according to any one of [1] to [8], which is used for applications that are heat-treated at 120°C or higher.

[10] A packaging bag, contents accommodated in the packaging bag, and the packaging bag is formed using a laminate, the laminate has a laminated structure including a base material layer, an intermediate layer, and a sealant layer in this order, the maximum opening heights H1 and H2 measured through the following steps satisfy the following conditions, 4 mm ≤ H1 6 mm ≤ H2 the maximum opening heights H1 and H2 are (2a) Taking 20 mm from the upper end of the packaging bag as the first position and the center in the height direction of the packaging bag as the second position, cutting from one side portion to the other side portion of the packaging bag at the first position, discharging the contents, and then measuring the maximum opening height H1 at the first position with the packaging bag placed on a horizontal table; (2b) After the step (2a), cutting from one side portion to the other side portion of the packaging bag at the second position and measuring the maximum opening height H2 at the second position with the packaging bag placed on a horizontal table; measured through a package, wherein the loop stiffness value of the laminate after heating at 128°C for 15 minutes is 80 mN or more and 220 mN or less.

Advantages of the Invention

[0008] According to one aspect of the present disclosure, there are provided a packaging bag and a package that are excellent in dischargeability and excellent in handling properties during opening. According to another aspect of the present disclosure, there is provided a laminate useful for manufacturing such a packaging bag and a package.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments in the present disclosure will be described. The same components are denoted by the same reference numerals, and redundant descriptions are omitted. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[0011] <Laminate> Hereinafter, a laminate according to an embodiment will be described. FIG. 1 is a schematic cross-sectional view showing the laminate according to this embodiment. The laminate 1 has a laminated structure including a first base material layer 10, a first adhesive layer 20, an intermediate layer 30, a second adhesive layer 40, and a sealant layer 50 in this order. The maximum opening heights H1 and H2 measured through the following steps (1a) to (1f) satisfy the following conditions. By satisfying the following conditions for the maximum opening heights H1 and H2, the packaging bag obtained using the laminate 1 is difficult to close the opening when discharging the contents with the opening at the lower part in the vertical direction. Therefore, even if no unevenness or the like for promoting the discharge of the contents is provided on the surface of the sealant layer (innermost layer) of the laminate 1 by additional processing or the like, the packaging bag has excellent discharge properties. 4 mm ≤ H1 6 mm ≤ H2

[0012] (1a) Step of preparing two laminates having a size of 90 mm in width and 140 mm in length as test pieces (1b) Step of overlapping two test pieces so that the sealant layers face each other and sealing three sides with a seal width of 5 mm to form a bag (1c) Step of injecting 70 g of water from the upper end of the bag and then sealing the upper end with a seal width of 5 mm to obtain a test body (1d) A step of heating the test piece under the conditions of a temperature of 128 °C, a time of 15 minutes, and a pressure of 0.3 MPa (1e) After the step (1d), cut from one side part to the other side part of the bag at a first position 20 mm from the upper end of the bag. After discharging water, measure the maximum opening height H1 at the first position with the bag placed on a horizontal table. (1f) After the step (1e), cut from one side part to the other side part of the bag at a second position 50 mm from the first position. Measure the maximum opening height H2 at the second position with the bag placed on a horizontal table.

[0013] The maximum opening heights H1 and H2 are the maximum intervals between the inner edges of the sealant layers.

[0014] Since the maximum opening height H1 is even more excellent in discharge property, it is preferably 4.3 mm or more, more preferably 5.0 mm or more. The maximum opening height H1 may be 7.0 mm or less. The maximum opening height H1 may be 4 mm or more and 7.0 mm or less, 4.3 mm or more and 7.0 mm or less, or 5.0 mm or more and 7.0 mm or less.

[0015] Since the maximum opening height H2 allows air to easily enter the entire main body of the packaging bag and the separation property of the contents located at the four corners of the main body is even more excellent, it is preferably 6.3 mm or more, more preferably 7.0 mm or more. The maximum opening height H2 may be 9.0 mm or less. The maximum opening height H2 may be 6.0 mm or more and 9.0 mm or less, 6.3 mm or more and 9.0 mm or less, or 7.0 mm or more and 9.0 mm or less.

[0016] The maximum opening heights H1 and H2 can be changed, for example, by adjusting the thermal shrinkage rates of the first base material layer and the second base material layer.

[0017] When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of MD calculated by the following formula (1) is preferably 1.0% or more, more preferably 1.8% or more, because the resulting packaging bag can be sufficiently opened and has even better dischargeability. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of MD calculated by the following formula (1) is preferably 3.0% or less from the viewpoint of suppressing appearance defects and conveyance defects. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of MD calculated by the following formula (1) may be 1.0% or more and 3.0% or less, or 1.8% or more and 3.0% or less.

[0018] When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the following formula (2) is preferably 1.0% or more, more preferably 1.8% or more, because the resulting packaging bag can be sufficiently opened and has even better dischargeability. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the following formula (2) is preferably 3.0% or less from the viewpoint of suppressing appearance defects and conveyance defects caused by shrinkage during bag making. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the following formula (2) may be 1.0% or more and 3.0% or less, or 1.8% or more and 3.0% or less.

[0019] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100 …(1) TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 …(2)

[0020] MD is the machine direction of the base material layer and the sealant layer, and TD is the transverse direction perpendicular thereto. For example, the film can be used to measure the orientation angle using a retardation measuring device (trade name: KOBRA, manufactured by Oji Scientific Instruments Co., Ltd.), and MD and TD can be distinguished from the orientation angle. For example, when the film is a sequentially biaxially stretched polypropylene film, the direction in which the molecular chains are oriented is considered to be TD.

[0021] The loop stiffness value after heating the laminate 1 at 128°C for 15 minutes is preferably 80 mN or more, more preferably 90 mN or more, preferably 220 mN or less, more preferably 170 mN or less, still more preferably 150 mN or less, still more preferably 130 mN or less, and particularly preferably 105 mN or less. When the loop stiffness value is within this range, the handling property at the time of opening the packaging bag is excellent. When the loop stiffness value is 80 mN or more, when discharging the contents by pinching both side portions of the packaging bag with both hands and pushing them toward the central portion of the packaging bag, the packaging bag is less likely to be distorted (less likely to be twisted), so it is easy to open and easy to maintain the opened shape. Therefore, the packaging bag tends to be even more excellent in discharge property. When the loop stiffness value is 150 mN or less, it becomes easier to pinch both side portions of the packaging bag with both hands and push them toward the central portion of the packaging bag. Therefore, the packaging bag is stably easy to open and tends to be even more excellent in discharge property. Also, it becomes easy to open the packaging bag with a light force and easy to maintain the opened shape. The loop stiffness value after heating the laminate 1 at 128°C for 15 minutes may be 80 mN or more and 220 mN or less, 80 mN or more and 170 mN or less, 80 mN or more and 150 mN or less, 80 mN or more and 130 mN or less, 80 mN or more and 105 mN or less, 90 mN or more and 220 mN or less, 90 mN or more and 170 mN or less, 90 mN or more and 150 mN or less, 90 mN or more and 130 mN or less, or 90 mN or more and 105 mN or less. The loop stiffness value can be measured by the method of the examples described later.

[0022] The loop stiffness value is a physical property indicating the rigidity of the film. The loop stiffness value increases somewhat also due to thermal shrinkage after heating, but it can be adjusted by the film thickness of the laminate, the crystallinity of each layer, and the Young's modulus. The larger the film thickness, the more the loop stiffness value tends to increase. The higher the crystallinity, the more the loop stiffness value tends to increase. The higher the Young's modulus, the more the loop stiffness value tends to increase. Conversely, the smaller the film thickness, the more the loop stiffness value tends to decrease. The lower the crystallinity, the more the loop stiffness value tends to decrease. The lower the Young's modulus, the more the loop stiffness value tends to decrease.

[0023] The proportion of the total mass of the polypropylene-based resin in the laminate 1 is preferably 90% by mass or more based on the total amount of the laminate 1, since the laminate 1 becomes a (monomaterial) packaging material made of a single material and has excellent recyclability. The content of the polypropylene-based resin in the laminate 1 may be 92.5% by mass or more, and may be 95% by mass or more, based on the total amount of the laminate 1.

[0024] Hereinafter, each layer of the laminate 1 will be described in detail.

[0025] [First base material layer 10] The first base material layer 10 is a plastic member that functions as the outermost layer in the laminate 1. The thickness of the first base material layer 10 is not particularly limited. Depending on the application, the thickness can be 6 to 200 μm, but from the viewpoint of reducing material for environmental load reduction, and from the viewpoints of obtaining excellent heat resistance, impact resistance, and excellent gas barrier properties, it may be 9 to 50 μm, may be 12 to 38 μm, may be 18 to 30 μm, or may be 15 to 30 μm.

[0026] From the viewpoint of recyclability of the laminate 1 and the like, the first base material layer 10 is, for example, a polyolefin film. The first base material layer 10 may contain a polypropylene film and may be made of a polypropylene film. The polypropylene film may be an acid-modified polypropylene film obtained by graft-modifying polypropylene with an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, or the like. As the polypropylene, polypropylene-based resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α olefin copolymer can be used.

[0027] Various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, an adhesion promoter, and an antistatic agent may be added to the polypropylene film constituting the first base material layer 10.

[0028] The polypropylene film constituting the first base material layer 10 may be a stretched film or an unstretched film. Since the polypropylene film is further excellent in discharge property, it is preferably a stretched polypropylene film.

[0029] When the first base material layer is heated at 128°C for 15 minutes, the heat shrinkage rate of MD obtained by the above formula (1) is preferably 2.0% or more, more preferably 3.0% or more, and still more preferably 4.0% or more because the discharge property is further excellent. From the viewpoint of handling property when opening the packaging bag, the heat shrinkage rate of the above MD may be 5.0% or less.

[0030] When the first base material layer is heated at 128°C for 15 minutes, the heat shrinkage rate of TD obtained by the above formula (2) is preferably more than 0%, more preferably 1.0% or more, and still more preferably 2.0% or more because the discharge property is further excellent. From the viewpoint of handling property when opening the packaging bag, the heat shrinkage rate of the above TD may be 3.0% or less.

[0031] When the first base material layer is heated at 128°C for 15 minutes, the heat shrinkage rate of MD obtained by the above formula (1) is defined as S1 MD and the heat shrinkage rate of TD obtained by the above formula (2) is defined as S1 TD When this is done, S1 MD and S1 TD The difference between them (S1 MD -S1 TD ) is preferably more than 0%, more preferably 1% or more, and still more preferably 1.5% or more from the viewpoint that the opening height tends to be high and the discharge property is further excellent. From the viewpoint of suppressing the distortion of the packaging bag that causes poor packaging of the packaging bag, it is preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less. S1 MD and S1 TD The difference between them (S1 MD -S1 TD) may be more than 0% and 5% or less, more than 0% and 4% or less, more than 0% and 3% or less, 1% or more and 5% or less, 1% or more and 4% or less, 1% or more and 3% or less, 1.5% or more and 5% or less, 1.5% or more and 4% or less, or 1.5% or more and 3% or less.

[0032] The first base material layer is heated at 128°C for 15 minutes, and the heat shrinkage rate of MD obtained by the above formula (1) is S1 MD When the second base material layer is heated at 128°C for 15 minutes, the heat shrinkage rate of MD obtained by the above formula (1) is S2 MD When it is set as, S1 MD And S2 MD The difference between (S1 MD ―S2 MD ) is preferably more than 0% from the viewpoint that the opening height tends to be high and the discharge property is further excellent, more preferably 0.25% or more, still more preferably 0.5% or more, and from the viewpoint of suppressing the generation of cracks in the gas barrier layer due to the difference in shrinkage of the base material, it is preferably 2.5% or less, more preferably 2.0% or less, and still more preferably 1.0% or less.

[0033] The first base material layer is heated at 128°C for 15 minutes, and the heat shrinkage rate of TD obtained by the above formula (2) is S1 TD When the second base material layer is heated at 128°C for 15 minutes, the heat shrinkage rate of TD obtained by the above formula (2) is S2 TD When it is set as, S1 TD And S2 TD The difference between (S1 TD ―S2 TD ) is preferably more than 0% from the viewpoint that the opening height tends to be high and the discharge property is further excellent, more preferably 0.3% or more, still more preferably 0.4% or more, and from the viewpoint of suppressing the generation of cracks in the gas barrier layer due to the difference in shrinkage of the base material, it is preferably 2.0% or less, more preferably 1.5% or less, and still more preferably 1.0% or less.

[0034] The first base material layer 10 may be subjected to various pretreatment such as corona treatment, plasma treatment, and frame treatment on its laminated surface, or may be provided with a coating layer such as an easy adhesion layer.

[0035] [First Adhesive Layer 20 and Second Adhesive Layer 40] The first adhesive layer 20 is a layered member that adheres the first base material layer 10 and the intermediate layer 30. The second adhesive layer 40 is a layered member that adheres the intermediate layer 30 and the sealant layer 50. As the material of the adhesive contained in the first adhesive layer 20 and the second adhesive layer 40, for example, polyester-isocyanate resin, urethane resin, polyether resin, etc. can be used. For using the packaging bag for retort use, a two-component curable urethane-based adhesive with retort resistance can be preferably used. From the viewpoint of environmental consideration, the adhesive may not contain 3-glycidoxypropyltrimethoxysilane (GPTMS). The first adhesive layer 20 and the second adhesive layer 40 may not contain chlorine. In this case, the first adhesive layer 20 and the second adhesive layer 40 can suppress the coloring of recycled resin etc. after recycling and the generation of odor by heat treatment. The first adhesive layer 20 and the second adhesive layer 40 may be formed of biomass material and may not contain a solvent from the viewpoint of environmental consideration.

[0036] The urethane-based adhesive contains a polyol and a polyisocyanate. When using the urethane-based adhesive, the first adhesive layer 20 and the second adhesive layer 40 may contain the polyurethane obtained by curing them, or may contain the uncured product of the urethane-based adhesive.

[0037] The polyol has two or more hydroxyl groups in one molecule. The polyisocyanate has two or more isocyanate groups in one molecule. The polyol and the polyisocyanate may react as a main agent and a curing agent respectively to produce polyurethane.

[0038] The polyol may contain at least one selected from the group consisting of polyester polyol and polyether polyol.

[0039] The polyisocyanate may be used alone or in combination of two or more. Examples of the polyisocyanate include aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, and aromatic polyisocyanate compounds.

[0040] The thickness of the first adhesive layer 20 is, for example, 0.5 μm or more and 10 μm or less. When the thickness of the first adhesive layer 20 is 0.5 μm or more, peeling between the first base material layer 10 and the intermediate layer 30 can be favorably suppressed. When the thickness of the first adhesive layer 20 is 10 μm or less, the laminate 1 can be easily made into a single material. The thickness of the first adhesive layer 20 may be 1 μm or more, 2 μm or more, 8 μm or less, 6 μm or less, or 5 μm or less.

[0041] The thickness of the second adhesive layer 40 is, for example, 0.5 μm or more and 10 μm or less. When the thickness of the second adhesive layer 40 is 0.5 μm or more, peeling between the intermediate layer 30 and the sealant layer 50 can be favorably suppressed. When the thickness of the second adhesive layer 40 is 10 μm or less, the laminate 1 can be easily made into a single material. The thickness of the first adhesive layer 20 may be 1 μm or more, 2 μm or more, 8 μm or less, 6 μm or less, or 5 μm or less.

[0042] [Intermediate layer 30] As shown in FIG. 1, the intermediate layer 30 has a second base material layer 31 and a gas barrier layer 32. The gas barrier layer 32 exhibits gas barrier properties against gases such as water vapor and oxygen. The gas barrier layer 32 has, in this order from the second base material layer 31 side, an anchor coat layer 32a, a vapor deposition layer 32b, and a barrier coat layer 32c.

[0043] The thickness of the intermediate layer may be the same as that of the first base material layer 10.

[0044] (Second base material layer 31) The thickness of the second base material layer 31 may be the same as that of the first base material layer 10. From the viewpoint of recyclability of the laminate 1 and the like, the second base material layer 31 is, for example, a polyolefin film. The second base material layer 31 may contain a polypropylene film and may be made of a polypropylene film. As the polypropylene film, the same one as the first base material layer 10 can be used. Various additives similar to those in the first base material layer 10 may be added to the polypropylene film. When the second base material layer 31 contains an anti-blocking agent, the addition of the anti-blocking agent may be suppressed in order to improve the smoothness of the surface on the side where the vapor deposition layer 32b is provided. The second base material layer 31 may be subjected to various pretreatment similar to those of the first base material layer 10 or may be provided with a coat layer.

[0045] When the second base material layer is heated at 128 °C for 15 minutes, the heat shrinkage rate of MD obtained by the above formula (1) is preferably 1.0% or more, more preferably 2.0% or more, and still more preferably 3.0% or more because the discharge property is further improved. The heat shrinkage rate of MD may be 5.0% or less from the viewpoint of the handling property when opening the packaging bag.

[0046] When the second base material layer is heated at 128 °C for 15 minutes, the heat shrinkage rate of TD obtained by the above formula (2) is preferably more than 0%, more preferably 1.0% or more, and still more preferably 2.0% or more because the discharge property is further improved. The heat shrinkage rate of TD may be 3.0% or less from the viewpoint of the handling property when opening the packaging bag.

[0047] The second base material layer is heated at 128 °C for 15 minutes, and the heat shrinkage rate of MD obtained by the above formula (1) is S2 MD and the heat shrinkage rate of TD obtained by the above formula (2) is S2 TD When it is set as, S2 MD and S2 TD When the difference between (S2 MD ―S2 TD) is preferably more than 0% from the viewpoint of being likely to have a high opening height and further excellent discharge property, more preferably 1% or more, still more preferably 1.5% or more, and preferably 5% or less, more preferably 4% or less, still more preferably 3% or less from the viewpoint of suppressing the distortion of the packaging bag that causes poor packaging of the packaging bag. S2 MD and S2 TD the difference from S2 MD - S2 TD ) may be more than 0% and 5% or less, more than 0% and 4% or less, more than 0% and 3% or less, 1% or more and 5% or less, 1% or more and 4% or less, 1% or more and 3% or less, 1.5% or more and 5% or less, 1.5% or more and 4% or less, or 1.5% or more and 3% or less.

[0048] (Anchor coat layer 32a) The anchor coat layer 32a functions as a layer that can improve the adhesion performance of the vapor deposition layer 32b on the second base material layer 31, and is provided directly above the second base material layer 31. For this reason, the anchor coat layer 32a is located between the second base material layer 31 and the vapor deposition layer 32b. By providing the anchor coat layer 32a, the smoothness of the surface on which the vapor deposition layer 32b is provided in the intermediate layer 30 can be improved. Note that by improving the smoothness, it becomes easier to form the vapor deposition layer 32b uniformly without defects, and it is easy to exhibit high barrier properties. The anchor coat layer 32a can be formed using, for example, an anchor coating agent.

[0049] As the anchor coating agent, a urethane resin is preferable. Examples of the urethane resin include polyester-based polyurethane resin, polyether-based polyurethane resin, and acrylic-based polyurethane resin. As the anchor coating agent, from the viewpoints of heat resistance and interlayer adhesion strength, polyester-based polyurethane resin and acrylic-based urethane resin are preferable. Particularly in a packaging material that undergoes a retort treatment, as the anchor coating agent, an acrylic-based polyurethane resin is more preferable.

[0050] The thickness of the anchor coat layer 32a is not particularly limited, but is preferably in the range of 0.01 to 5 μm, more preferably in the range of 0.03 to 3 μm, and particularly preferably in the range of 0.05 to 2 μm. When the thickness of the anchor coat layer 32a is equal to or greater than the above lower limit value, sufficient interlayer adhesion strength tends to be obtained. On the other hand, when it is equal to or less than the above upper limit value, the desired gas barrier property tends to be easily exhibited.

[0051] As a method for coating the anchor coat layer 32a on the second base material layer 31, known coating methods can be used without particular limitation, and examples include dipping methods (dipping methods), spraying, coaters, printing machines, methods using brushes, etc. In addition, as the types of coaters and printing machines used in these methods and their coating methods, there are gravure coaters such as direct gravure method, reverse gravure method, kiss reverse gravure method, offset gravure method, reverse roll coater, micro gravure coater, chamber doctor combined coater, air knife coater, dip coater, bar coater, comma coater, die coater, etc.

[0052] The coating amount of the anchor coat layer 32a is preferably such that the mass per 1 m 2 after coating and drying the anchor coating agent is 0.01 to 5 g / m 2 and more preferably 0.03 to 3 g / m 2 After coating and drying the anchor coating agent, when the mass per 1 m 2 is equal to or greater than the above lower limit, film formation tends to be sufficient. On the other hand, when it is equal to or less than the above upper limit, it tends to dry sufficiently and it is difficult for the solvent to remain.

[0053] The method for drying the anchor coat layer 32a is not particularly limited, and examples thereof include a method of natural drying, a method of drying in an oven set at a predetermined temperature, and a method using a dryer attached to the coater, such as an arch dryer, a floating dryer, a drum dryer, an infrared dryer, etc. Further, the drying conditions can be appropriately selected according to the drying method. For example, in the method of drying in an oven, it is preferable to dry at a temperature of 60 to 100°C for about 1 second to 2 minutes.

[0054] As the anchor coat layer 32a, a polyvinyl alcohol-based resin can be used instead of the above polyurethane resin. The polyvinyl alcohol-based resin may be any resin having a vinyl alcohol unit formed by saponifying a vinyl ester unit, and examples thereof include polyvinyl alcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH).

[0055] Examples of PVA include resins obtained by polymerizing vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprylate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versatate alone and then saponifying them. The PVA may be a modified PVA that has been copolymerization-modified or post-modified. The modified PVA can be obtained, for example, by copolymerizing a vinyl ester and an unsaturated monomer copolymerizable with the vinyl ester and then saponifying the resulting copolymer. Examples of unsaturated monomers copolymerizable with vinyl esters include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadecene; hydroxy group-containing α-olefins such as 3-buten-1-ol, 4-pentin-1-ol, and 5-hexen-1-ol; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, and undecylenic acid; nitriles such as acrylonitrile and methacrylonitrile; amides such as diacetoneacrylamide, acrylamide, and methacrylamide; olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid; vinyl compounds such as alkyl vinyl ether, dimethylallyl vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinyl ethylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerin monoallyl ether, and 3,4-diacetoxy-1-butene; vinylidene chloride, 1,4-diacetoxy-2-butene, and vinylene carbonate.

[0056] The degree of polymerization of PVA is preferably from 300 to 3000. If the degree of polymerization is less than 300, the barrier property is likely to decrease, and if it exceeds 3000, the viscosity is too high and the coating applicability is likely to decrease. The saponification degree of PVA is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. Also, the saponification degree of PVA may be 100 mol% or less, or 99.9 mol% or less. The degree of polymerization and saponification degree of PVA can be measured in accordance with the method described in JIS K 6726 (1994).

[0057] EVOH is generally obtained by saponifying a copolymer of ethylene and a vinyl ester such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprylate, vinyl laurate, vinyl stearate, vinyl pivalate, vinyl versatate, etc.

[0058] The degree of polymerization of EVOH is preferably 300 to 3000. When the degree of polymerization is less than 300, the barrier property is likely to decrease, and when it exceeds 3000, the viscosity is too high and the coating suitability is likely to decrease. The saponification degree of the vinyl ester component of EVOH is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. Also, the saponification degree of EVOH may be 100 mol% or less, or 99.9 mol% or less. The saponification degree of EVOH is determined from the peak area of the hydrogen atoms contained in the vinyl ester structure and the peak area of the hydrogen atoms contained in the vinyl alcohol structure by performing nuclear magnetic resonance (1H-NMR) measurement.

[0059] The ethylene unit content of EVOH is 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and particularly preferably 25 mol% or more. Also, the ethylene unit content of EVOH is preferably 65 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. When the ethylene unit content is 10 mol% or more, the gas barrier property or dimensional stability under high humidity can be maintained well. On the other hand, when the ethylene unit content is 65 mol% or less, the gas barrier property can be enhanced. The ethylene unit content of EVOH can be determined by the NMR method.

[0060] When using a polyvinyl alcohol-based resin as the anchor coat layer 32a, examples of the formation method of the anchor coat layer 32a include coating using a polyvinyl alcohol-based resin solution, multilayer extrusion, etc.

[0061] (Vapor deposition layer 32b) The vapor deposition layer 32b is a layer (gas barrier layer) that exhibits gas barrier properties against water vapor and oxygen, and contains at least one of a metal and an inorganic oxide. The vapor deposition layer 32b is provided directly above the anchor coat layer 32a. The vapor deposition layer 32b may have a single-layer structure or a laminated structure. Therefore, the vapor deposition layer 32b contains at least one of a metal vapor deposition layer and an inorganic oxide layer. When the vapor deposition layer 32b includes a metal vapor deposition layer, examples of the metal contained in the metal vapor deposition layer include aluminum and stainless steel. When the vapor deposition layer 32b includes an inorganic oxide layer, examples of the inorganic oxide contained in the inorganic oxide layer include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoints of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. Further, from the viewpoint of excellent tensile stretchability during processing, the inorganic oxide layer is preferably a layer using silicon oxide. By using the inorganic oxide layer, a very thin layer within a range that does not affect the recyclability of the laminate 1 can provide high barrier properties.

[0062] When the vapor deposition layer 32b is an inorganic oxide layer using silicon oxide, it is desirable that the O / Si ratio of the inorganic oxide layer is 1.7 or more. When the O / Si ratio is 1.7 or more, the content ratio of metallic Si is suppressed and good transparency is easily obtained. Further, the O / Si ratio is preferably 2.0 or less. When the O / Si ratio is 2.0 or less, the crystallinity of SiO can be increased to prevent the inorganic oxide layer from becoming too hard, and good tensile resistance can be obtained. Thereby, generation of cracks in the inorganic oxide layer can be suppressed when the barrier coat layer 32c is laminated. Also, although the first base material layer 10 may shrink due to heat during boiling or retort processing even after being formed into a packaging bag, when the O / Si ratio is 2.0 or less, the inorganic oxide layer can easily follow the above shrinkage, and a decrease in barrier properties can be suppressed. From the viewpoint of more sufficiently obtaining these effects, the O / Si ratio of the inorganic oxide layer is preferably 1.75 or more and 1.9 or less, and more preferably 1.8 or more and 1.85 or less.

[0063] When the vapor deposition layer 32b is an inorganic oxide layer using silicon oxide, the O / Si ratio of the inorganic oxide layer can be determined by X-ray photoelectron spectroscopy (XPS). For example, the measurement apparatus can be an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., trade name: JPS-90MXV), the X-ray source can use non-monochromatized MgKα (1253.6 eV), and the measurement can be performed with an X-ray output of 100 W (10 kV - 10 mA). For quantitative analysis to obtain the O / Si ratio, relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p can be used.

[0064] The thickness of the vapor deposition layer 32b is, for example, 5 nm or more and 80 nm or less. When the thickness of the vapor deposition layer 32b is 5 nm or more, sufficient water vapor barrier properties can be obtained. Also, when the thickness of the vapor deposition layer 32b is 80 nm or less, the generation of cracks due to deformation caused by internal stress of the thin film can be suppressed, and a decrease in water vapor barrier properties can be suppressed. Note that when the thickness of the vapor deposition layer 32b exceeds 80 nm, the cost tends to increase due to an increase in the amount of material used and a longer film formation time, etc., so it is not preferable from an economic point of view. From the same viewpoint as above, the thickness of the vapor deposition layer 32b may be 20 nm or more and 40 nm or less.

[0065] The vapor deposition layer 32b can be formed, for example, by vacuum film formation. In vacuum film formation, physical vapor deposition methods or chemical vapor deposition methods can be used. Examples of physical vapor deposition methods include, but are not limited to, vacuum evaporation, sputtering, ion plating, etc. Examples of chemical vapor deposition methods include, but are not limited to, thermal CVD, plasma CVD, photo CVD, etc.

[0066] In the above-mentioned vacuum film formation, a resistance heating type vacuum evaporation method, an EB (Electron Beam) heating type vacuum evaporation method, an induction heating type vacuum evaporation method, a sputtering method, a reactive sputtering method, a dual magnetron sputtering method, a plasma chemical vapor deposition method (PECVD method), etc. are particularly preferably used. However, considering productivity, at present, the vacuum evaporation method is the most excellent. As the heating means of the vacuum evaporation method, it is preferable to use any one of an electron beam heating method, a resistance heating method, and an induction heating method.

[0067] (Barrier coating layer 32c) The barrier coating layer 32c is a coating layer (gas barrier coating layer) having gas barrier properties and is provided on the vapor deposition layer 32b. The barrier coating layer 32c is, for example, a layer formed using a gas barrier coating layer forming composition (hereinafter also referred to as a coating agent) containing at least one selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, and their hydrolyzates.

[0068] From the viewpoint of more sufficiently maintaining the gas barrier properties after heat treatment such as retort treatment, the coating agent preferably contains at least a silane coupling agent or its hydrolyzate, and more preferably contains at least one selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, and their hydrolyzates, and a silane coupling agent or its hydrolyzate. Even more preferably, it contains a hydroxyl group-containing polymer compound or its hydrolyzate, a metal alkoxide or its hydrolyzate, and a silane coupling agent or its hydrolyzate. The coating agent can be prepared, for example, by mixing a solution obtained by dissolving a hydroxyl group-containing polymer compound, which is a water-soluble polymer, in an aqueous (water or water / alcohol mixture) solvent with a metal alkoxide and a silane coupling agent that have been directly or previously hydrolyzed.

[0069] The components contained in the coating agent for forming the barrier coat layer 32c will be described in detail. Examples of the hydroxyl group-containing polymer compound used in the coating agent include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, and the like. Among these, when polyvinyl alcohol (PVA) is used as the coating agent for the barrier coat layer 32c, it is preferable because of its particularly excellent gas barrier properties.

[0070] From the viewpoint of obtaining excellent gas barrier properties, the barrier coat layer 32c is preferably formed from a composition containing at least one selected from the group consisting of a metal alkoxide represented by the following general formula (I) and its hydrolyzate. M(OR 1 ) m (R 2 ) n-m …(I) In the above general formula (I), R 1 and R 2 are each independently a monovalent organic group having 1 to 8 carbon atoms, and are preferably an alkyl group such as a methyl group or an ethyl group. M represents an n-valent metal atom such as Si, Ti, Al, or Zr. m is an integer of 1 to n. When there are a plurality of R 1 or R 2 , R 1 each other or R 2 each other may be the same or different.

[0071] Specific examples of the metal alkoxide include tetraethoxysilane [Si(OC2H5)4], triisopropoxyaluminum [Al(OC3H7)3], and the like. Tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

[0072] Examples of the silane coupling agent include compounds represented by the following general formula (II). Si(OR 11 ) p (R 12 ) 3-p R 13…(II) In the general formula (II) above, R 11 represents an alkyl group such as a methyl group or an ethyl group, and R 12 represents a monovalent organic group such as an alkyl group, an aralkyl group, an aryl group, an alkenyl group, an alkyl group substituted with an acryloxy group, or an alkyl group substituted with a methacryloxy group. R 13 represents a monovalent organic functional group, and p represents an integer of 1 to 3. When there are a plurality of R 11 or R 12 , R 11 themselves or R 12 themselves may be the same or different. Examples of the monovalent organic functional group represented by R 13 include a glycidyloxy group, an epoxy group, a mercapto group, a hydroxyl group, an amino group, an alkyl group substituted with a halogen atom, or a monovalent organic functional group containing an isocyanate group.

[0073] Specific examples of the silane coupling agent include silane coupling agents such as vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropylmethyldimethoxysilane.

[0074] In addition, the silane coupling agent may be a polymer obtained by polymerizing the compound represented by the general formula (II). As the polymer, a trimer is preferable, and more preferably 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate. This is a polycondensate of 3-isocyanatealkylalkoxysilane. It is known that 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate has no chemical reactivity in the isocyanate part, but the reactivity is ensured by the polarity of the nurate part. Generally, it is added to adhesives and the like in the same manner as 3-isocyanatealkylalkoxylane and is known as an adhesion improver. Therefore, by adding 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate to a hydroxyl group-containing polymer compound, the water resistance of the gas barrier coating layer can be improved by hydrogen bonding. 3-Isocyanatealkylalkoxylane has high reactivity and low liquid stability, while 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate has a nurate part that is not water-soluble due to its polarity, but is easily dispersed in an aqueous solution and can keep the liquid viscosity stable. Also, the water resistance performance is equivalent to that of 3-isocyanatealkylalkoxylane and 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate.

[0075] 1,3,5-Tris(3-trialkoxysilylalkyl)isocyanurate may be produced by thermal condensation of 3-isocyanatopropylalkoxysilane, and the raw material 3-isocyanatopropylalkoxysilane may be included, but there is no particular problem. More preferably, it is 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate, and even more preferably 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate. Since this methoxy group has a high hydrolysis rate and those containing a propyl group can be obtained relatively inexpensively, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is practically advantageous.

[0076] In addition, in a range that does not impair the gas barrier property, an isocyanate compound or known additives such as a dispersant, a stabilizer, a viscosity modifier, and a colorant can be added to the coating agent as necessary.

[0077] The thickness of the barrier coating layer 32c is preferably 50 to 1000 nm, more preferably 100 to 500 nm. When the thickness of the barrier coating layer 32c is 50 nm or more, there is a tendency to obtain a more sufficient gas barrier property, and when it is 1000 nm or less, there is a tendency to maintain sufficient flexibility.

[0078] The coating liquid for forming the barrier coating layer 32c can be applied, for example, by a dipping method, a roll coating method, a gravure coating method, a reverse gravure coating method, an air knife coating method, a comma coating method, a die coating method, a screen printing method, a spray coating method, a gravure offset method, or the like. The coating film formed by applying this coating liquid can be dried, for example, by a hot air drying method, a hot roll drying method, a high-frequency irradiation method, an infrared irradiation method, a UV irradiation method, or a combination thereof.

[0079] The temperature when drying the above coating film can be, for example, 50 to 150°C, preferably 70 to 100°C. By setting the temperature during drying within the above range, the generation of cracks in the vapor deposition layer 32b and the barrier coating layer 32c can be further suppressed, and an excellent barrier property can be exhibited.

[0080] The barrier coating layer 32c may be formed using a coating agent containing a polyvinyl alcohol-based resin and a silane compound. An acid catalyst, an alkali catalyst, a photoinitiator, etc. may be added to the coating agent as necessary.

[0081] The polyvinyl alcohol-based resin is as described above. Examples of the silane compound include silane coupling agents, polysilazanes, siloxanes, etc. Specific examples include tetramethoxysilane, tetraethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, hexamethyldisilazane, etc.

[0082] [Sealant layer 50] The sealant layer 50 is a layer that imparts heat-sealing properties to the laminate 1. From the perspective of the recyclability of the laminate 1, etc., the sealant layer 50 is a polyolefin film like the first base material layer 10. In the present embodiment, the sealant layer 50 has a single-layer structure and is a resin layer mainly made of polypropylene, but is not limited thereto. The sealant layer 50 may contain a polypropylene film and may be composed of a polypropylene film.

[0083] The polypropylene film may be an acid-modified polypropylene film obtained by graft-modifying polypropylene using an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, etc. As the polypropylene, polypropylene-based resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, etc. can be used.

[0084] The polypropylene film constituting the sealant layer 50 is preferably an unstretched polypropylene film from the perspective of enhancing the heat-sealing properties.

[0085] Various additives such as flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, etc. may be added to the polypropylene film constituting the sealant layer 50.

[0086] The thickness of the sealant layer 50 is determined by factors such as the mass of the contents and the shape of the packaging bag, but it may generally be a thickness of 30 to 150 μm, and may be a thickness of 50 to 80 μm.

[0087] When the sealant layer 50 is heated at 128°C for 15 minutes, although the reason is not clear, by thermally expanding in the MD direction and thermally contracting in the TD direction, it is easy to obtain the opening height of the packaging bag. From the same perspective, when the sealant layer 50 is heated at 128°C for 15 minutes, the thermal shrinkage rate of MD obtained by the above formula (1) is preferably -1.0% or more, more preferably -0.5% or more, and preferably less than 0%.

[0088] When the sealant layer 50 is heated at 128°C for 15 minutes, the thermal shrinkage rate of TD obtained by the above formula (2) is preferably 0% or more and preferably 1.0% or less.

[0089] As the lamination method of the sealant layer 50, a dry lamination method in which the film-like sealant layer made of the above-mentioned polypropylene is laminated with an adhesive such as a one-component curing type or two-component curing type urethane-based adhesive, a non-solvent lamination method in which the film-like sealant layer is laminated using a solvent-free adhesive, an extrusion lamination method in which the above-mentioned polypropylene is heated and melted, extruded in a curtain shape, and laminated, etc. can all be laminated by known methods.

[0090] Among the above lamination methods, the dry lamination method is particularly preferred because of its high resistance to retort treatment, especially high-temperature hot water treatment at 120°C or higher. On the other hand, if it is used for applications where the packaging bag is treated at a temperature of 85°C or lower, the lamination method is not particularly limited.

[0091] The laminate according to one embodiment has been described above, but the laminate of the present disclosure is not limited to the above embodiment. For example, the laminate may further include a printing layer.

[0092] [Printing layer] The printing layer can be provided, for example, on at least one surface of the first base material layer 10. The printing layer is provided at a position visible from the outside of the laminate 1 for the purpose of displaying information about the contents, identifying the contents, improving concealment, or improving the design of the packaging bag. The printing method and the printing ink are not particularly limited, and are appropriately selected from known printing methods and printing inks in consideration of printability on the film, design properties such as color tone, adhesion, and safety as a food container. As the printing method, for example, a gravure printing method, an offset printing method, a gravure offset printing method, a flexographic printing method, an inkjet printing method, or the like can be used. Among them, the gravure printing method can be preferably used from the viewpoints of productivity and high definition of the pattern.

[0093] In order to enhance the adhesion of the printing layer, various pretreatment such as corona treatment, plasma treatment, and frame treatment may be performed on the surface of the layer on which the printing layer is provided, or a coating layer such as an easy-adhesion layer may be provided.

[0094] Further, the laminate of the present disclosure may not include the anchor coat layer 32a. The laminate of the present disclosure may not include the barrier coat layer 32c. The lamination order of the second base material layer 31, the anchor coat layer 32a, the vapor deposition layer 32b, and the barrier coat layer 32c may be interchanged. Further, the laminate of the present disclosure may not include at least one of the first adhesive layer 20 and the second adhesive layer 40.

[0095] <Package> Hereinafter, a package according to an embodiment will be described. FIG. 2 is a schematic plan view of an example of the package according to the present embodiment. The package 200 includes a packaging bag 100 and contents (not shown) accommodated in the packaging bag.

[0096] The packaging bag 100 is formed, for example, by overlapping two laminates 1 so that the sealant layers face each other and heat-sealing the four sides.

[0097] The packaging bag 100 is a rectangular bag having a main body portion 101 for containing the contents and a seal portion 102 located at an end of the main body portion 101. The shape of the main body portion 101 is not particularly limited, and for example, it exhibits a rectangular shape when viewed from a predetermined direction. At least a part of the outer surface of the main body portion 101 may be printed. In the main body portion 101, for example, in addition to the contents, a specific gas such as nitrogen may be contained. The seal portion 102 is a portion where a part and another part of the sealant layer 50 provided in the laminate 1 are bonded together. In the seal portion 102, a part and another part of the sealant layer 50 provided in the laminate 1 are in close contact with each other. The seal portion 102 is formed, for example, by heating and compressing (i.e., heat-sealing) a part and another part of the sealant layer 50 provided in the laminate 1, but is not limited thereto. For example, the seal portion 102 may be formed by cold sealing or the like.

[0098] The package 200 satisfies the following conditions for the maximum opening heights H1 and H2 measured through the following steps. By satisfying the following conditions for the maximum opening heights H1 and H2, when the package 200 discharges the contents with the opening portion at the lower part in the vertical direction, it becomes difficult for the opening portion to close, and the discharge property is excellent. 4 mm ≤ H1 6 mm ≤ H2

[0099] (2a) A step of setting 20 mm from the upper end of the packaging bag as the first position, setting the center in the height direction of the packaging bag as the second position, cutting from one side portion to the other side portion of the packaging bag at the first position, discharging the contents, and then measuring the maximum opening height H1 at the first position in a state where the packaging bag is placed on a horizontal table (2b) After the step (2a), a step of cutting from one side portion to the other side portion of the packaging bag at the second position and measuring the maximum opening height H2 at the second position in a state where the packaging bag is placed on a horizontal table

[0100] The first position is indicated by the virtual line I-I where the distance L1 from the upper end is 20 mm in FIG. 2. The second position is indicated by the virtual line II-II where the distances from the upper end and the lower end are the same at 70 mm in FIG. 2. FIG. 3 is an end view at the virtual line I-I. The maximum opening height H1 is the maximum distance between the inner edges of the sealant layers as shown in FIG. 3. The same applies to the maximum opening height H2. The numerical ranges of the maximum opening heights H1 and H2 may be the same as those of the maximum opening heights H1 and H2 of the laminate 1.

[0101] The seal width S of the packaging bag 100 may be, for example, 2 to 10 mm. The width W1 of the packaging bag 100 may be, for example, 80 to 150 mm. The height W2 of the packaging bag 100 may be, for example, 120 to 200 mm.

[0102] The package 200 may be subjected to a heat treatment at 80°C or higher, 120°C or higher, or 135°C or lower. Examples of the heat treatment include retort treatment and boiling treatment.

[0103] Retort treatment is generally a method of sterilizing microorganisms such as mold, yeast, and bacteria by heating and pressurizing in order to preserve foods, pharmaceuticals, etc. Usually, a packaging bag containing foods, etc. is heated and pressurized under the conditions of 105 to 140°C, 0.15 to 0.30 MPa for 10 to 120 minutes. Retort apparatuses include a steam type that uses heating steam and a hot water type that uses pressurized heated water, and they are appropriately selected according to the sterilization conditions of the foods, etc. that are the contents. Boiling treatment is a method of sterilizing by moist heat in order to preserve foods, pharmaceuticals, etc. Usually, although it depends on the contents, a packaging bag containing foods, etc. is subjected to a moist heat sterilization treatment under the conditions of 60 to 100°C at atmospheric pressure for 10 to 120 minutes. Boiling treatment is usually performed at 100°C or lower using a hot water tank. As methods, there are a batch type in which it is immersed in a hot water tank at a constant temperature, treated for a certain time, and then taken out, and a continuous type in which it is passed through the hot water tank in a tunnel type for treatment.

[0104] Examples of the contents include foods and pharmaceuticals. Since the packaging bag 100 has excellent dischargeability, the contents may generally include water, which is difficult to discharge. The water content may be, for example, 60% by mass or more, preferably 70% by mass or more, more preferably 75% by mass or more, based on the total amount of the contents. Examples of the contents containing water include cooked foods such as soups and pasta sauces, and pet foods.

[0105] As described above, the package according to one embodiment has been described. However, the package of the present disclosure is not limited to the above embodiment. For example, the packaging bag may be a standing pouch-shaped packaging bag, a two-sided bag, a three-sided bag, a clasp bag, or a gusset bag. The packaging bag may not include a resealing portion and a notch. The packaging bag may include a knot. The notch may be V-shaped, U-shaped, I-shaped, or the like. Further, a group of scars may be formed instead of the notch.

Examples

[0106] Hereinafter, examples of the present disclosure will be specifically described. However, the present disclosure is not limited to the following examples.

[0107] <Preparation of Materials> The following materials were prepared as the first base material layer, the second base material layer, the sealant layer, and the adhesive. [First Base Material Layer] ·OPP1A: Biaxially oriented polypropylene film (thickness 20 μm) ·OPP1B: Biaxially oriented polypropylene film (thickness 20 μm) ·OPP1C: Biaxially oriented polypropylene film (thickness 20 μm) ·PET: Polyethylene terephthalate film (thickness 12 μm) [Second Base Material Layer] ·OPP2A: Biaxially oriented polypropylene film (thickness 20 μm) ·OPP2B: Biaxially oriented polypropylene film (thickness 20 μm) (Sealant Layer) ·CPP-A: Unoriented polypropylene film (thickness 60 μm) · CPP-B: Unstretched polypropylene film (thickness 80 μm) · CPP-C: Unstretched polypropylene film (thickness 60 μm) · CPP-D: Unstretched polypropylene film (thickness 40 μm) · CPP-E: Unstretched polypropylene film (thickness 70 μm or 80 μm) (Adhesive) · Manufactured by Mitsui Chemicals, Inc., product name: Main agent A525 / Hardening agent A52

[0108] [Preparation of anchor coating agent] Acrylic polyol and tolylene diisocyanate were mixed so that the number of NCO groups of tolylene diisocyanate was equal to the number of OH groups of acrylic polyol, and diluted with ethyl acetate so that the total solid content (total amount of acrylic polyol and tolylene diisocyanate) was 5% by mass. To the diluted mixture, β-(3,4-epoxycyclohexyl)trimethoxysilane was further added in an amount of 5 parts by mass with respect to 100 parts by mass of the total amount of acrylic polyol and tolylene diisocyanate, and these were mixed to prepare an anchor coating agent.

[0109] [Preparation of coating liquid for barrier coating layer] The following Liquid A, Liquid B and Liquid C were mixed at a mass ratio of 65 / 25 / 10 respectively to prepare a coating liquid for barrier coating layer. Liquid A: A hydrolysis solution with a solid content of 5% by mass (in terms of SiO2) obtained by adding 72.1 g of 0.1N hydrochloric acid to 17.9 g of tetraethoxysilane (Si(OC2H5)4) and 10 g of methanol and stirring for 30 minutes for hydrolysis. Liquid B: A 5% by mass water / methanol solution of polyvinyl alcohol (mass ratio of water:methanol is 95:5). Liquid C: A hydrolysis solution obtained by diluting 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate with a mixture of water / isopropyl alcohol (mass ratio of water:isopropyl alcohol is 1:1) to a solid content of 5% by mass.

[0110] <Manufacture of Gas Barrier Film (Intermediate Layer)> (Examples 1 to 5, Comparative Examples 1, 2, 5, 6) The materials shown in Table 1 were used as the second base material layer. The above composition for forming the anchor coat layer was applied by a gravure roll coating method on the corona-treated surface of the second base material layer, dried and cured at 60 °C, and the coating amount was 0.1 g / m 2 An anchor coat layer made of a polyester-based polyurethane resin with a coating amount of 0.1 g / m was formed.

[0111] Next, a transparent inorganic oxide layer (silica vapor deposition layer) made of silicon oxide with a thickness of 30 nm was formed by a vacuum vapor deposition apparatus using an electron beam heating method. As the silica vapor deposition layer, a vapor deposition layer with an O / Si ratio of 1.8 was formed by adjusting the vapor deposition material type. The O / Si ratio was measured with an X-ray photoelectron spectroscopy analyzer (manufactured by JEOL Ltd., trade name: JPS-90MXV), using a non-monochromatized MgKα (1253.6 eV) X-ray source and an X-ray output of 100 W (10 kV - 10 mA). For the quantitative analysis to obtain the O / Si ratio, relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p were used respectively.

[0112] Next, the above coating liquid for the barrier coat layer was applied on the inorganic oxide layer by a gravure roll coating method, and heat-dried in an oven under the conditions of a tension of 20 N / m and a drying temperature of 120 °C to form an overcoat layer with a thickness of 0.3 μm. Thus, a gas barrier film having a laminated structure of a second base material layer / anchor coat layer / vapor deposition layer / overcoat layer was obtained.

[0113] <Manufacture of Laminated Body> Based on the combinations of each layer shown in Table 1, laminated bodies of each example and comparative example were manufactured. The manufacturing method of the laminated body is as follows.

[0114] (Examples 1 to 5, Comparative Examples 1, 2, 5, 6) A first base material layer was laminated on the surface of the overcoat layer side of the gas barrier film by a dry lamination method via an adhesive. A sealant layer was similarly laminated on the other surface of the second base material layer of the gas barrier film. Thereby, a laminate having a laminated structure of a first base material layer / adhesive layer / overcoat layer / vapor deposition layer / anchor coat layer / second base material layer / adhesive layer / sealant layer was produced.

[0115] (Comparative Examples 3 and 4) AL foil (thickness: 10 μm, MD heat shrinkage rate: 0%, TD heat shrinkage rate: 0%) was prepared. A first base material layer was laminated on one surface of the AL foil by a dry lamination method via an adhesive. A sealant layer was similarly laminated on the surface of the AL foil opposite to the surface on which the first base material layer was laminated. Thereby, a laminate having a laminated structure of a first base material layer / adhesive layer / AL foil layer / adhesive layer / sealant layer was produced.

[0116] <Loop stefness value> The laminates of each example and comparative example were retort-treated by heating under the conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa. The loop stefness value of the heated laminate was measured. For the measurement, a loop stefness tester manufactured by Toyo Seiki Seisaku-sho, Ltd. was used. A test film with a TD of 15 mm and an MD of 200 mm was prepared from the heated laminate. A loop with a loop size of 85 mm × 15 mm was formed by fixing both ends of the test film with chucks. This loop was compressed by a pressure head under the conditions of a compression speed of 3.3 mm / min, a compression time of 3 seconds, and a compression distance of 20 mm, and the load of the pressure head at that time was measured. As the loop stefness value, the maximum value of the load measured in this test was adopted. The compression distance represents the distance when the pressure head and the chuck are closest to each other. The results are shown in Table 2.

[0117] <Measurement of maximum opening heights H1 and H2> The maximum opening heights H1 and H2 were measured through the following steps. For the maximum opening height H1, the average value of the measured values for three laminates was adopted. Similarly, for the maximum opening height H2, the average value of the measured values for three laminates was adopted. The results are shown in Table 2.

[0118] (1a) Step of preparing two laminates with a size of 90 mm in width and 140 mm in length as test pieces (1b) Step of overlapping two test pieces so that the sealant layers face each other and sealing three sides with a seal width of 5 mm to form a bag (1c) Step of injecting 70 g of water from the upper end of the bag and then sealing the upper end with a seal width of 5 mm to obtain a test specimen (1d) Step of heating the test specimen under the conditions of a temperature of 128 °C, a time of 15 minutes, and a pressure of 0.3 MPa (1e) After the step (1d), at the first position 20 mm from the upper end of the bag, cut from one side part of the bag to the other side part, drain the water, and then measure the maximum opening height H1 at the first position with the bag placed on a horizontal table (1f) After the step (1e), at the second position 50 mm from the first position, cut from one side part of the bag to the other side part, and measure the maximum opening height H2 at the second position with the bag placed on a horizontal table

[0119] In step (1b), an impulse sealer was used. In step (1c), after injecting water into the bag, while folding the upper part of the bag, the air inside the bag was removed and the upper end was sealed in that state. In step (1d), the test specimen was heated with the main surface arranged horizontally. The heating was performed by a shower method of spraying water on the test specimen. In step (1e), after draining the water, the inside of the bag was gently wiped with a Kimwipe to remove moisture. Also, before measuring the maximum opening height H1, with the bag placed on a horizontal table, the main surface was pressed with the palm from the lower end to the upper end of the bag with a force of 2 - 3 Kg. In step (1f), before measuring the maximum opening height H2, with the bag placed on a horizontal table, the main surface was pressed with the palm from the lower end to the upper end of the bag with a force of 2 - 3 Kg.

[0120] <Measurement of the shrinkage rates of the first base material layer, the second base material layer, the sealant layer, and the laminate> The thermal shrinkage rates of the first base material layer, the second base material layer, the sealant layer, and the laminate in each example and comparative example were measured according to the following procedure. The results are shown in Table 1.

[0121] (1) As shown in FIG. 4, the layer or laminate to be measured was cut out into a 200 mm × 200 mm size to obtain a measurement sample 500. (2) As shown in FIG. 4, two straight lines L1 and L2 with a length of 120 mm or more parallel to the TD of the measurement sample 500 were drawn with an interval of 100 mm. (3) As shown in FIG. 4, two straight lines L3 and L4 with a length of 120 mm or more parallel to the MD of the measurement sample 500 were drawn with an interval of 100 mm. (4) As shown in FIG. 4, scale marks N1 to N7 were written at seven locations on the straight line L1 at intervals of 20 mm. Scale marks were also written on the straight lines L2 to L4 in the same manner. At this time, when the scale marks N1 to N7 on the straight line L1 and the scale marks N1 to N7 on the straight line L2 were connected by a straight line, the positions of the scale marks on the straight lines L1 and L2 were adjusted so that the straight line was parallel to the MD. Also, when the scale marks N1 to N7 on the straight line L3 and the scale marks N1 to N7 on the straight line L4 were connected by a straight line, the positions of the scale marks on the straight lines L3 and L4 were adjusted so that the straight line was parallel to the TD. (5) The measurement sample was heated under the conditions of 128°C, 15 minutes, and 0.3 MPa. After heating, the measurement sample was left at room temperature (25°C) for 30 minutes. (6) The linear distance between the scale mark N1 (the intersection of L1 and N1) on the straight line L1 and the scale mark N1 (the intersection of L2 and N1) on the straight line L2 was measured before and after heating as the MD length, and the MD thermal shrinkage rate was obtained by the following formula (1). Similarly, the MD thermal shrinkage rates at the positions of each of the scale marks N1 to N7 were obtained, and their average value was taken as the MD thermal shrinkage rate of the measurement sample 500. MD thermal shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100 …(1) (7) The linear distance between the scale N1 of the straight line L3 (the intersection point of L3 and N1) and the scale N1 of the straight line L4 (the intersection point of L4 and N1) was measured before and after heating, and the TD shrinkage rate was obtained by the following formula (2). Similarly, the TD shrinkage rates at the respective positions of the scales N1 to N7 were obtained, and their average value was taken as the TD shrinkage rate of the measurement sample 500. TD shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 …(2)

[0122] <Exhaustibility> Two laminates with a size of 90 mm in width and 140 mm in length were prepared as test pieces. The two test pieces were overlapped so that the sealant layers faced each other. Three sides of the test piece were sealed with an impulse sealer (seal width 5 mm) to obtain a packaging bag. A wet pet hood (about 50 g) was filled from the upper end of the packaging bag. The upper end of the packaging bag was sealed with an impulse sealer (seal width 5 mm). Thereby, a package comprising a packaging bag and the contents (wet pet hood) was obtained.

[0123] The package was heated under the conditions of a temperature of 128 °C, a time of 15 minutes, and a pressure of 0.3 MPa. The heating was performed by a shower method in which water was sprayed on the package. A cut was made from one side portion to the other side portion of the bag at the first position 20 mm from the upper end of the packaging bag after heating to form an opening. The maximum opening height of the opening was measured. The contents were discharged by maintaining the packaging bag for 30 seconds with the opening at the lower part in the vertical direction. After 15 seconds, both side portions of the packaging bag were pinched with both hands and pushed toward the inside of the packaging bag. The amount of the contents discharged in 30 seconds was measured. The discharge rate was calculated based on the following formula. Discharge rate (%) = amount of discharged contents (g) / filling amount of contents (g) × 100

[0124] The maximum opening height of the opening and the discharge rate were evaluated according to the following criteria. The results are shown in Table 2. (Criteria) A: The maximum opening height is over 25 mm and the discharge rate is over 90%. B: The maximum opening height is 20 mm or more and less than 25 mm and the discharge rate is over 90%. C: Other than evaluations of A and B

[0125] <Handling property when opening the packaging bag> Two laminates sized 90 mm in width and 140 mm in length were prepared as test pieces. The two test pieces were overlapped so that the sealant layers faced each other. Three sides of the test pieces were sealed with an impulse sealer (seal width: 5 mm) to obtain a packaging bag. The upper end of the packaging bag was filled with a wet pet food pouch (about 50 g). The upper end of the packaging bag was sealed with an impulse sealer (seal width: 5 mm). Thereby, a package comprising the packaging bag and the contents (wet pet food pouch) was obtained. The package was heated under the conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa. The heating was performed by a shower method in which water was sprayed onto the package. A cut was made from one side portion to the other side portion of the bag at a first position 20 mm from the upper end of the packaging bag after heating to form an opening. The handling property when opening the packaging bag was evaluated by evaluating the ease of force adjustment and the ease of maintaining the opening shape when grasping the seal portions at both ends of the package and pushing the seal portions closer to each other according to the following criteria A to D. The evaluation was performed according to the following criteria. The results are shown in Table 2. (Criteria) A: The opening opens with a light force and is easy to maintain. B: The opening is easy to open and is easy to maintain. C: The packaging bag is hard and the opening is difficult to open, but the opening is easy to maintain. D: The opening is distorted and difficult to open, and difficult to maintain.

[0126]

Table 1

[0127]

Table 2

Explanation of reference numerals

[0128] 1... laminate, 30... intermediate layer, 50... sealant layer, 100... packaging bag, 200... package.

Claims

1. a base material layer, an intermediate layer, a sealant layer, a laminate having a laminated structure including these in this order, wherein the maximum opening heights H1 and H2 measured through the following steps satisfy the following conditions, 4 mm ≤ H1 6 mm ≤ H2 the maximum opening heights H1 and H2 are (1a) preparing two pieces of the laminate having a size of 90 mm in width and 140 mm in length as test pieces, (1b) overlapping the two test pieces so that the sealant layers face each other and sealing three sides with a seal width of 5 mm to form a bag, (1c) injecting 70 g of water from the upper end of the bag and then sealing the upper end with a seal width of 5 mm to obtain a test body, (1d) heating the test body under the conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa, (1e) after the step (1d), cutting from one side portion to the other side portion of the bag at a first position 20 mm from the upper end of the bag, discharging the water, and then measuring the maximum opening height H1 at the first position with the bag placed on a horizontal table, (1f) after the step (1e), cutting from one side portion to the other side portion of the bag at a second position 50 mm from the first position and measuring the maximum opening height H2 at the second position with the bag placed on a horizontal table, measured through, a laminate having a loop stiffness value of 80 mN or more and 220 mN or less after heating at 128°C for 15 minutes.

2. The laminate according to claim 1, wherein when heated at 128°C for 15 minutes, the MD heat shrinkage rate obtained by the following formula (1) is 1.0% or more and 3.0% or less, and the TD heat shrinkage rate obtained by the following formula (2) is 1.0% or more and 3.0% or less. MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100... (1) TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100... (2)

3. The laminate according to claim 1, wherein when heated at 128°C for 15 minutes, the sealant layer thermally expands in the MD direction and thermally contracts in the TD direction.

4. Heat the base material layer at 128°C for 15 minutes, and let the heat shrinkage rate of MD, which is obtained by the following formula (1), be S1 ＭＤ and let the heat shrinkage rate of TD, which is obtained by the following formula (2), be S1 ＴＤ When this is done, if the difference (S1 ＭＤ −S1 ＴＤ ) between S1 ＭＤ and S1 ＴＤ is more than 0% and 5% or less, the laminate according to claim 1 MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100... (1) TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100... (2)

5. the intermediate layer has a second base material layer, The second base material layer is heated at 128°C for 15 minutes, and the heat shrinkage rate of MD obtained by the following formula (1) is defined as S2 ＭＤ and the heat shrinkage rate of TD obtained by the following formula (2) is defined as S2 ＴＤ When this is done, the difference (S2 ＭＤ -S2 ＴＤ ) between S2 ＭＤ and S2 ＴＤ is more than 0% and 5% or less. The laminate according to claim 1 MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100 …(1) TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 …(2)

6. The laminate according to claim 1, wherein the maximum opening heights H1 and H2 satisfy the following conditions. 4 mm ≤ H1 ≤ 7 mm 6 mm ≤ H2 ≤ 9 mm

7. The laminate according to claim 1, wherein the base material layer, the intermediate layer, and the sealant layer contain a polypropylene-based resin, and the proportion of the total mass of the polypropylene-based resin in the laminate is 90% by mass or more.

8. A packaging bag formed using the laminate according to any one of claims 1 to 7.

9. The packaging bag according to claim 8, which is used for applications that are heat-treated at 120°C or higher.

10. A packaging bag, and the contents contained in the packaging bag, and is provided with, wherein the packaging bag is formed using a laminate, the laminate has a laminated structure including a base material layer, an intermediate layer, and a sealant layer in this order, the maximum opening heights H1 and H2 measured through the following steps satisfy the following conditions, 4 mm ≤ H1 6 mm ≤ H2 the maximum opening heights H1 and H2 are, (2a) A step of setting 20 mm from the upper end of the packaging bag as the first position, the center in the height direction of the packaging bag as the second position, cutting from one side portion to the other side portion of the packaging bag at the first position, discharging the contents, and then measuring the maximum opening height H1 at the first position with the packaging bag placed on a horizontal table; and (2b) after the step (2a), cutting from one side portion to the other side portion of the packaging bag at the second position, and measuring the maximum opening height H2 at the second position with the packaging bag placed on a horizontal table; and are measured through, a packaging body, wherein the loop stiffness value after heating the laminate at 128°C for 15 minutes is 80 mN or more and 220 mN or less.

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