Laminated body, packaging bag, and packaging body

Abstract

A laminate having a laminated structure comprising a base layer, an intermediate layer, and a sealant layer in this order, the maximum opening heights (H1, H2) measured by a predetermined step satisfying the following conditions: the ring stiffness value after heating at 128 DEG C for 15 minutes is 80-220 mN (inclusive). 4mm < = H1 and 6mm < = H2

Description

Technical Field

[0001] This disclosure relates to laminates, packaging bags, and packaging bodies. Background Technology

[0002] Laminates are widely used as packaging materials for food, pharmaceuticals, and other products that undergo heat sterilization processes such as boiling and cooking. Laminates with the following films are known: biaxially oriented PET (polyethylene terephthalate) film with excellent heat resistance and toughness, and polyolefin films such as polyethylene or polypropylene as sealing layers (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-178357 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, it is required that the contents contained in the packaging material be easily drainable. Existing laminates still have room for improvement in terms of drainability.

[0008] In addition, the packaging material must be easy to handle when opening.

[0009] One aspect of this disclosure provides packaging bags and packaging bodies with excellent discharge properties and excellent operability when opened. Other aspects of this disclosure provide laminates for manufacturing such packaging bags and packaging bodies.

[0010] Methods for solving problems

[0011] To address the aforementioned issues, this disclosure provides the following laminates, packaging bags, and packaging bodies.

[0012] [1] A laminated body having a laminated structure comprising the following layers in sequence:

[0013] Substrate layer

[0014] intermediate layer, and

[0015] Sealing layer,

[0016] The maximum opening heights H1 and H2, measured through the following processes, meet the following conditions:

[0017] 4mm≤H1

[0018] 6mm≤H2

[0019] The maximum opening heights H1 and H2 mentioned above were measured through the following processes:

[0020] (1a) The process of preparing two of the above-mentioned laminates with a width of 90 mm and a length of 140 mm as test pieces;

[0021] (1b) The process of overlapping the two test pieces with the sealing layers facing each other and sealing the three sides with a sealing width of 5 mm to form a bag;

[0022] (1c) The process of injecting 70g of water into the upper end of the bag and sealing the upper end with a sealing width of 5mm to obtain the test body;

[0023] (1d) The procedure of heating the above test specimen at a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa;

[0024] (1e) After the above-described (1d) process, at a first position 20 mm from the upper end of the bag, the bag is cut from one side to the other, the water is drained, and the maximum opening height H1 at the first position is measured while the bag is placed on a water platform; and

[0025] (1f) After the above-described (1e) process, at a second position 50 mm from the first position, the bag is cut from one side to the other, and the maximum opening height H2 at the second position is measured while the bag is placed on a horizontal platform.

[0026] The loop stiffness value of the above-mentioned laminate after heating at 128°C for 15 minutes is above 80mN and below 220mN.

[0027] [2] According to the laminate described in [1], when heated at 128°C for 15 minutes, the MD heat shrinkage rate calculated by the following formula (1) is more than 1.0% and less than 3.0%, and the TD heat shrinkage rate calculated by the following formula (2) is more than 1.0% and less than 3.0%.

[0028] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100… (1)

[0029] TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100… (2)

[0030] [3] According to the laminate described in [1] or [2], wherein when heated at 128°C for 15 minutes, the sealing layer thermally expands on the MD and thermally shrinks on the TD.

[0031] [4] The laminate according to any one of [1] to [3], wherein the substrate layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the following formula (1) is set as S1. MD And the thermal shrinkage rate of TD obtained by the following formula (2) is set as S1. TD At that time, S1 MD With S1 TD The difference (S1) MD -S1 TD () Greater than 0% and less than 5%.

[0032] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100… (1)

[0033] TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100… (2)

[0034] [5] The laminate according to any one of [1] to [4], wherein the intermediate layer has a second substrate layer, the second substrate layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the following formula (1) is set as S2. MD And the thermal shrinkage rate of TD obtained by the following formula (2) is set as S2. TD At that time, S2 MD With S2 TD The difference (S2) MD -S2 TD () Greater than 0% and less than 5%.

[0035] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100… (1)

[0036] TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100… (2)

[0037] [6] The laminate according to any one of [1] to [5], wherein the maximum opening heights H1 and H2 satisfy the following conditions:

[0038] 4mm≤H1≤7mm

[0039] 6mm≤H2≤9mm.

[0040] [7] The laminate according to any one of [1] to [6], wherein the substrate layer, the intermediate layer and the sealing layer comprise a polypropylene resin, and the total mass percentage of the polypropylene resin in the laminate is 90% by mass or more.

[0041] [8] A packaging bag formed using any one of [1] to [7].

[0042] [9] The packaging bag according to any one of [1] to [8] is used for heat treatment at 120°C or above.

[0043]

[10] A packaging body, comprising:

[0044] Packaging bags, and

[0045] The contents contained in the aforementioned packaging bag,

[0046] The aforementioned packaging bags are formed using laminated materials.

[0047] The aforementioned laminate has a stacked structure comprising a substrate layer, an intermediate layer, and a sealing layer in sequence.

[0048] The maximum opening heights H1 and H2, measured through the following processes, meet the following conditions:

[0049] 4mm≤H1

[0050] 6mm≤H2

[0051] The maximum opening heights H1 and H2 mentioned above were measured through the following processes:

[0052] (2a) A process of cutting the packaging bag from one side to the other at the first position, with 20 mm from the top of the packaging bag as the first position and the center of the packaging bag in the height direction as the second position, discharging the contents, and measuring the maximum opening height H1 at the first position while the packaging bag is placed on a horizontal platform; and

[0053] (2b) After the above-described (2a) process, the packaging bag is cut from one side to the other at the second position, and the maximum opening height H2 at the second position is measured while the packaging bag is placed on a horizontal platform.

[0054] The ring stiffness of the above-mentioned laminated body after heating at 128°C for 15 minutes is above 80mN and below 220mN.

[0055] The effects of the invention

[0056] According to one aspect of this disclosure, packaging bags and packaging bodies with excellent discharge properties and excellent operability when opened are provided. According to other aspects of this disclosure, laminates for manufacturing such packaging bags and packaging bodies are provided. Attached Figure Description

[0057] [ Figure 1 ] Figure 1This is a schematic cross-sectional view showing a laminated body according to one embodiment.

[0058] [ Figure 2 ] Figure 2 This is a schematic plan view of an example of a package.

[0059] [ Figure 3 ] Figure 3 yes Figure 2 The end view of the imaginary line II.

[0060] [ Figure 4 ] Figure 4 This is a schematic diagram illustrating the method for determining the thermal shrinkage rate during heating. Detailed Implementation

[0061] The embodiments of this disclosure will now be described. It should be noted that the same symbols are used to denote the same constituent elements, and repeated descriptions are omitted. Furthermore, the dimensional ratios in the drawings are not limited to those shown in the figures.

[0062] <Layered Body>

[0063] The following describes a laminate according to one embodiment. Figure 1 This is a schematic cross-sectional view showing the laminate according to this embodiment. The laminate 1 has a laminated structure comprising a first substrate layer 10, a first adhesive layer 20, an intermediate layer 30, a second adhesive layer 40, and a sealing layer 50 in sequence. The maximum opening heights H1 and H2, measured by the following steps (1a) to (1f), satisfy the following conditions. When the maximum opening heights H1 and H2 satisfy the following conditions, the opening of the packaging bag obtained using the laminate 1 is not easily closed when the contents are discharged with the opening located at the lower part in the vertical direction. Therefore, even without providing unevenness or other features to promote the discharge of contents on the surface of the sealing layer (innermost layer) of the laminate 1 by means of additional processing, the discharge performance of the packaging bag is excellent.

[0064] 4mm≤H1

[0065] 6mm≤H2

[0066] (1a) The procedure of preparing two laminates with a width of 90 mm and a length of 140 mm as test pieces.

[0067] (1b) The process of overlapping two test pieces with the sealing layers facing each other and sealing three sides with a sealing width of 5 mm to form a bag.

[0068] (1c) The procedure of injecting 70g of water into the top of the bag and then sealing the top with a sealing width of 5mm to obtain the test specimen.

[0069] (1d) Procedure of heating the test specimen at a temperature of 128°C for 15 minutes and a pressure of 0.3 MPa.

[0070] (1e) After step (1d), at the first position 20mm from the top of the bag, cut the bag from one side to the other, drain the water, and then measure the maximum opening height H1 at the first position while the bag is placed on a water platform.

[0071] (1f) After step (1e), at a second position 50 mm from the first position, cut the bag from one side to the other, and measure the maximum opening height H2 at the second position while the bag is placed on a horizontal platform.

[0072] The maximum opening heights H1 and H2 are the maximum spacing between the inner edges of the sealing layers.

[0073] From the perspective of superior discharge performance, the maximum opening height H1 is preferably 4.3 mm or more, more preferably 5.0 mm or more. The maximum opening height H1 can be 7.0 mm or less. The maximum opening height H1 can 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.

[0074] Considering the ease with which air can enter the entire main body of the packaging bag and the superior detachment of contents at the four corners of the main body, the maximum opening height H2 is preferably 6.3 mm or more, more preferably 7.0 mm or more. The maximum opening height H2 can be 9.0 mm or less. Specifically, the maximum opening height H2 can 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.

[0075] The maximum opening heights H1 and H2 can be changed, for example, by adjusting the thermal shrinkage rates of the first and second substrate layers.

[0076] From the perspective of obtaining a packaging bag with sufficient opening and better drainage, 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. From the viewpoint of suppressing poor appearance and poor transport, 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. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of MD calculated by the following formula (1) can be 1.0% or more and 3.0% or less, or 1.8% or more and 3.0% or less.

[0077] From the perspective of obtaining a packaging bag with sufficient opening and better drainage, 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. From the viewpoint of suppressing appearance defects and poor conveying 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) is preferably 3.0% or less. When the laminate 1 is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the following formula (2) can be 1.0% or more and 3.0% or less, or 1.8% or more and 3.0% or less.

[0078] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100… (1)

[0079] TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100… (2)

[0080] MD is the flow direction (machine direction: longitudinal) between the substrate layer and the sealing layer, and TD is its transverse direction (transverse direction: transverse). For membranes, for example, the orientation angle can be measured using a phase difference measuring device (trade name: KOBRA, manufactured by Oji Keiseki Kogyo Co., Ltd.), and MD and TD can be distinguished based on the orientation angle. For example, in the case of a successively biaxially stretched polypropylene membrane, the direction of molecular chain orientation can be considered as TD.

[0081] The ring stiffness value of the laminate 1 after heating 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, further preferably 150 mN or less, further preferably 130 mN or less, and particularly preferably 105 mN or less. When the ring stiffness value is within this range, the operability of opening the packaging bag is excellent. When the ring stiffness value is 80 mN or more, the packaging bag is not easily deformed (not easily twisted) when the contents are expelled by pinching the two sides of the packaging bag with both hands and pressing towards the center of the packaging bag, so it is easy to open and easy to maintain the shape of the opening. Therefore, the expulsion performance of the packaging bag tends to be better. When the ring stiffness value is 150 mN or less, it is easy to pinch the two sides of the packaging bag with both hands and press towards the center of the packaging bag. Therefore, the packaging bag is easy to open stably, and the expulsion performance tends to be better. In addition, it is easy to open the packaging bag with a lighter force and easy to maintain the shape of the opening. The ring stiffness value of laminate 1 after heating at 128°C for 15 minutes can be 80mN to 220mN, 80mN to 170mN, 80mN to 150mN, 80mN to 130mN, 80mN to 105mN, 90mN to 220mN, 90mN to 170mN, 90mN to 150mN, 90mN to 130mN, or 90mN to 105mN. The ring stiffness value can be determined by the method described in the embodiments below.

[0082] Ring stiffness is a physical property indicating the rigidity of a film. The ring stiffness increases somewhat due to thermal contraction after heating and can be adjusted based on the film thickness, crystallinity of each layer, and Young's modulus. A larger film thickness tends to result in a larger ring stiffness. Higher crystallinity also tends to result in a larger ring stiffness. A higher Young's modulus also tends to result in a larger ring stiffness. Conversely, a smaller film thickness tends to result in a smaller ring stiffness. Lower crystallinity also tends to result in a smaller ring stiffness. A lower Young's modulus also tends to result in a smaller ring stiffness.

[0083] Considering that laminate 1 is a packaging material composed of a single material and has excellent reusability, the total mass percentage of polypropylene resin in laminate 1 is preferably 90% or more, based on the total amount of laminate 1. Based on the total amount of laminate 1, the content of polypropylene resin in laminate 1 can be 92.5% or more, or 95% or more.

[0084] The following is a detailed description of each layer of the laminate 1.

[0085] [First substrate layer 10]

[0086] The first substrate layer 10 is a plastic component that functions as the outermost layer of the laminate 1. The thickness of the first substrate layer 10 is not particularly limited. Depending on the application, the thickness can be set to 6–200 μm. From the viewpoint of reducing the amount of material used to mitigate environmental impact, and from the viewpoint of obtaining excellent heat resistance, impact resistance, and excellent gas barrier properties, the thickness can be 9–50 μm, 12–38 μm, 18–30 μm, or 15–30 μm.

[0087] From the viewpoint of reusability of laminate 1, the first substrate layer 10 is, for example, a polyolefin film. The first substrate layer 10 may include a polypropylene film or may be composed of a polypropylene film. The polypropylene film may be an acid-modified polypropylene film obtained by grafting polypropylene with unsaturated carboxylic acids, anhydrides of unsaturated carboxylic acids, esters of unsaturated carboxylic acids, etc. Furthermore, as polypropylene, homopolymer polypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, and other polypropylene-based resins may be used.

[0088] Various additives such as flame retardants, slip agents, anti-blocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents can be added to the polypropylene film constituting the first substrate layer 10.

[0089] The polypropylene film constituting the first substrate layer 10 can be a stretched film or an unstretched film. From the perspective of superior discharge performance, the polypropylene film is preferably a stretched polypropylene film.

[0090] From the perspective of superior discharge performance, when the first substrate layer is heated at 128°C for 15 minutes, the heat shrinkage rate of the MD calculated by the above formula (1) is preferably 2.0% or more, more preferably 3.0% or more, and even more preferably 4.0% or more. From the viewpoint of operability when opening the packaging bag, the heat shrinkage rate of the above-mentioned MD can be 5.0% or less.

[0091] From the perspective of superior discharge performance, when the first substrate layer is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the above formula (2) is preferably greater than 0%, more preferably 1.0% or more, and even more preferably 2.0% or more. From the viewpoint of operability when opening the packaging bag, the heat shrinkage rate of the above-mentioned TD can be 3.0% or less.

[0092] The first substrate layer was heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the above formula (1) was set as S1. MD And the thermal shrinkage rate of TD obtained from the above equation (2) is set as S1. TD From the perspective that the opening height is more likely to be higher and the discharge performance is more favorable, S1 MD With S1 TD The difference (S1) MD-S1 TD S1 is preferably greater than 0%, more preferably more than 1%, and even more preferably more than 1.5%. From the viewpoint of suppressing packaging bag deformation that causes poor packaging bag binding, S1 MD With S1 TD The difference (S1) MD -S1 TD S1 is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less. MD With S1 TD The difference (S1) MD -S1 TD () can be greater than 0% and less than 5%, greater than 0% and less than 4%, greater than 0% and less than 3%, more than 1% and less than 5%, more than 1% and less than 4%, more than 1% and less than 3%, more than 1.5% and less than 5%, more than 1.5% and less than 4%, or more than 1.5% and less than 3%.

[0093] The first substrate layer was heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the above formula (1) was set as S1. MD And the thermal shrinkage rate of MD calculated by the above formula (1) when the second substrate layer is heated at 128°C for 15 minutes is set as S2. MD From the perspective that the opening height is more likely to be higher and the discharge performance is more favorable, S1 MD With S2 MD The difference (S1) MD -S2 MD S1 is preferably greater than 0%, more preferably 0.25% or more, and even more preferably 0.5% or more. From the viewpoint of suppressing cracking of the gas barrier layer caused by differential shrinkage of the substrate, S1 MD With S2 MD The difference (S1) MD -S2 MD The content is preferably 2.5% or less, more preferably 2.0% or less, and even more preferably 1.0% or less.

[0094] The first substrate layer was heated at 128°C for 15 minutes, and the thermal shrinkage rate of TD calculated by the above formula (2) was set as S1. TD And the thermal shrinkage rate of TD calculated by the above formula (2) when the second substrate layer is heated at 128°C for 15 minutes is set as S2. TD From the perspective that the opening height is more likely to be higher and the discharge performance is more favorable, S1 TD With S2 TD The difference (S1) TD -S2 TD S1 is preferably greater than 0%, more preferably 0.3% or more, and even more preferably 0.4% or more. From the viewpoint of suppressing cracking of the gas barrier layer caused by differential shrinkage of the substrate, S1TD With S2 TD The difference (S1) TD -S2 TD The content is preferably 2.0% or less, more preferably 1.5% or less, and even more preferably 1.0% or less.

[0095] Various pretreatments such as corona treatment, plasma treatment, and flame treatment can be applied to the laminated surface of the first substrate layer 10, or coatings such as easy-to-adhere layers can be applied.

[0096] [First adhesive layer 20 and second adhesive layer 40]

[0097] The first adhesive layer 20 is a layered component that bonds the first substrate layer 10 and the intermediate layer 30 together. The second adhesive layer 40 is a layered component that bonds the intermediate layer 30 and the sealing layer 50 together. Materials used as adhesives in the first adhesive layer 20 and the second adhesive layer 40 may include, for example, polyester-isocyanate resins, urethane resins, polyether resins, etc. For packaging bags intended for retort use, a two-component curing urethane adhesive with retort resistance is preferred. It should be noted that, from an environmental perspective, the adhesive may also be free of 3-glycidoxypropyltrimethoxysilane (GPTMS). The first adhesive layer 20 and the second adhesive layer 40 may also be free of chlorine. In this case, the first adhesive layer 20 and the second adhesive layer 40 can suppress discoloration of recycled resins and the odor generated by heat treatment. From an environmental perspective, the first adhesive layer 20 and the second adhesive layer 40 can also be formed from biomass materials and may not contain solvents.

[0098] The urethane-based adhesive contains polyols and polyisocyanates. When using urethane-based adhesives, the first adhesive layer 20 and the second adhesive layer 40 may contain polyurethane obtained by curing them, or they may contain uncured urethane-based adhesive.

[0099] Polyols contain two or more hydroxyl groups in one molecule. Polyisocyanates contain two or more isocyanate groups in one molecule. Polyols and polyisocyanates can react as the main agent and curing agent, respectively, to produce polyurethane.

[0100] The polyol may contain at least one selected from the group consisting of polyester polyols and polyether polyols.

[0101] Polyisocyanates can be used alone or in combination of two or more. Examples of polyisocyanates include aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, and aromatic polyisocyanate compounds.

[0102] 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 substrate layer 10 and the intermediate layer 30 can be effectively suppressed. When the thickness of the first adhesive layer 20 is 10 μm or less, the laminate 1 can be easily made from a single material. The thickness of the first adhesive layer 20 can be 1 μm or more, 2 μm or more, 8 μm or less, 6 μm or less, or 5 μm or less.

[0103] 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 sealing layer 50 can be effectively suppressed. When the thickness of the second adhesive layer 40 is 10 μm or less, the laminate 1 can be easily made from a single material. The thickness of the second adhesive layer 40 can be 1 μm or more, 2 μm or more, 8 μm or less, 6 μm or less, or 5 μm or less.

[0104] [Middle Layer 30]

[0105] like Figure 1 As shown, the intermediate layer 30 has a second substrate 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, sequentially from the second substrate layer 31 side, an anchoring coating 32a, a vapor-deposited layer 32b, and a barrier coating 32c.

[0106] The thickness of the intermediate layer can be the same as that of the first substrate layer 10.

[0107] (Second substrate layer 31)

[0108] The thickness of the second substrate layer 31 can be the same as that of the first substrate layer 10. From the viewpoint of reusability of the laminate 1, the second substrate layer 31 is, for example, a polyolefin film. The second substrate layer 31 can contain a polypropylene film or be composed of a polypropylene film. The polypropylene film can be made of the same material as the first substrate layer 10. Various additives, the same as those in the first substrate layer 10, can be added to the polypropylene film. When the second substrate layer 31 contains an anti-blocking agent, the addition of the anti-blocking agent can be suppressed in order to improve the smoothness of the surface on the side where the vapor-deposited layer 32b is to be formed. Various pretreatments, the same as those in the first substrate layer 10, can also be performed on the second substrate layer 31, or a coating can be formed.

[0109] From the perspective of superior discharge performance, when the second substrate layer is heated at 128°C for 15 minutes, the heat shrinkage rate of the MD calculated by the above formula (1) is preferably 1.0% or more, more preferably 2.0% or more, and even more preferably 3.0% or more. From the viewpoint of operability when opening the packaging bag, the heat shrinkage rate of the above-mentioned MD can be 5.0% or less.

[0110] From the perspective of superior discharge performance, when the second substrate layer is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the above formula (2) is preferably greater than 0%, more preferably 1.0% or more, and even more preferably 2.0% or more. From the viewpoint of operability when opening the packaging bag, the heat shrinkage rate of the above-mentioned TD can be 3.0% or less.

[0111] The second substrate layer was heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated from the above formula (1) was set as S2. MD And let the thermal shrinkage rate of TD obtained from the above equation (2) be S2. TD From the perspective that the opening height is more likely to be higher and the discharge performance is more favorable, S2 MD With S2 TD The difference (S2) MD -S2 TD S2 is preferably greater than 0%, more preferably more than 1%, and even more preferably more than 1.5%. From the viewpoint of suppressing packaging bag deformation that causes poor packaging bag binding, S2 MD With S2 TD The difference (S2) MD -S2 TD S2 is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less. MD With S2 TD The difference (S2) MD -S2 TD () can be greater than 0% and less than 5%, greater than 0% and less than 4%, greater than 0% and less than 3%, more than 1% and less than 5%, more than 1% and less than 4%, more than 1% and less than 3%, more than 1.5% and less than 5%, more than 1.5% and less than 4%, or more than 1.5% and less than 3%.

[0112] (Anchoring coating 32a)

[0113] Anchoring coating 32a functions as a layer that improves the adhesion of vapor-deposited layer 32b on the second substrate layer 31, and is disposed directly above the second substrate layer 31. Therefore, anchoring coating 32a is located between the second substrate layer 31 and the vapor-deposited layer 32b. By providing anchoring coating 32a, the smoothness of the surface of the vapor-deposited layer 32b to be disposed in the intermediate layer 30 can be improved. It should be noted that by improving smoothness, the vapor-deposited layer 32b can be easily and uniformly formed without defects, and it is easier to exhibit high barrier properties. Anchoring coating 32a can be formed, for example, using an anchoring coating agent.

[0114] As an anchoring coating agent, urethane resin is preferred. Examples of urethane resins include polyester polyurethane resins, polyether polyurethane resins, and acrylic polyurethane resins. From the viewpoint of heat resistance and interlayer adhesion strength, polyester polyurethane resins and acrylic polyurethane resins are preferred as anchoring coating agents. Especially in packaging materials subjected to boiling or retorting treatments, acrylic polyurethane resins are more preferred as anchoring coating agents.

[0115] The thickness of the anchoring coating 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 anchoring coating 32a is above the aforementioned lower limit, more sufficient interlayer bond strength tends to be obtained; on the other hand, when it is below the aforementioned upper limit, the desired air barrier properties tend to be more easily exhibited.

[0116] There are no particular limitations on the method for applying the anchoring coating 32a to the second substrate layer 31. Known coating methods can be used, such as dipping methods, methods using sprayers, coating machines, printing machines, brushes, etc. Furthermore, the types of coating machines and printing machines used in these methods, and their coating methods, can include: direct gravure coating, reverse gravure coating, kiss-type reverse gravure coating, offset gravure coating, reverse roller coating machines, micro-gravure coating machines, cavity-type doctor blade coating machines, air knife coating machines, dip coating machines, bar coating machines, comma coating machines, and die coating machines.

[0117] As the coating amount of anchoring coating 32a, it is calculated as the amount of anchoring coating applied and dried per 1m. 2 The preferred mass is 0.01–5 g / m³. 2 More preferably, it is 0.03–3 g / m 2 After applying and drying the anchoring agent, every 1m 2 When the quality is above the lower limit mentioned above, film formation tends to become sufficient; on the other hand, when it is below the upper limit mentioned above, it tends to dry sufficiently easily and solvent residue is not easily left behind.

[0118] There are no particular limitations on the method for drying the anchoring coating 32a, and examples include: natural drying, drying in an oven set to a specified temperature, and using a dryer attached to the coating machine—such as an arched dryer, a floating dryer, a drum dryer, an infrared dryer, etc. Furthermore, the drying conditions can be appropriately selected depending on the drying method; for example, in the oven drying method, drying at a temperature of 60–100°C for approximately 1 second to 2 minutes is preferred.

[0119] As the anchoring coating 32a, a polyvinyl alcohol-based resin can be used instead of the polyurethane resin described above. As the polyvinyl alcohol-based resin, any resin containing ethylene alcohol units formed by saponification of ethylene ester units is acceptable; examples include polyvinyl alcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH).

[0120] Examples of PVAs include resins obtained by homopolymerizing vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl decanoate, vinyl laurate, vinyl stearate, vinyl neopentanoate, and vinyl tert-carbonate, followed by saponification. PVAs can be copolymerized or post-modified PVAs. Modified PVAs are obtained, for example, by copolymerizing vinyl esters with unsaturated monomers that can copolymerize with vinyl esters, followed by saponification. Examples of unsaturated monomers that can copolymerize with vinyl esters include: olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadecene; hydroxyl-containing α-olefins such as 3-buten-1-ol, 4-pentyn-1-ol, and 5-hexen-1-ol; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, and undecenoic acid; nitriles such as acrylonitrile and methacrylonitrile; and diacetone acrylamide and acrylamide. Amides such as methacrylamide; olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methyl allyl sulfonic acid; vinyl compounds such as alkyl vinyl ethers, dimethyl allyl vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerol monoallyl ether, and 3,4-diacetoxy-1-butene; vinylidene chloride, 1,4-diacetoxy-2-butene, and vinylene carbonate.

[0121] The degree of polymerization of PVA is preferably between 300 and 3000. When the degree of polymerization is less than 300, the barrier properties tend to decrease, and when it exceeds 3000, the viscosity becomes too high, and the coating adaptability tends to decrease. The degree of saponification of PVA is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. In addition, the degree of saponification of PVA can be less than 100 mol% or less, or less than 99.9 mol%. The degree of polymerization and degree of saponification of PVA can be determined according to the method described in JIS K 6726 (1994).

[0122] EVOH is generally obtained by saponifying copolymers of ethylene with vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl decanoate, vinyl laurate, vinyl stearate, vinyl neopentanoate, vinyl tert-carbonate, etc.

[0123] The degree of polymerization of EVOH is preferably between 300 and 3000. When the degree of polymerization is less than 300, the barrier properties tend to decrease; conversely, when it exceeds 3000, the viscosity becomes too high, and the coating adaptability tends to decrease. The degree of saponification 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. Furthermore, the degree of saponification of EVOH can be less than 100 mol% or less, or less than 99.9 mol%. The degree of saponification of EVOH can be determined by nuclear magnetic resonance (1H-NMR) measurement, based on the peak areas of hydrogen atoms in the vinyl ester structure and the peak areas of hydrogen atoms in the vinyl alcohol structure.

[0124] The ethylene unit content of EVOH is 10 mol% or more, more preferably 15 mol% or more, further preferably 20 mol% or more, and particularly preferably 25 mol% or more. Furthermore, the ethylene unit content of EVOH is preferably 65 mol% or less, more preferably 55 mol% or less, and further preferably 50 mol% or less. When the ethylene unit content is 10 mol% or more, good gas barrier properties or dimensional stability under high humidity can be maintained. On the other hand, when the ethylene unit content is 65 mol% or less, gas barrier properties can be improved. The ethylene unit content of EVOH can be determined by NMR.

[0125] When using polyvinyl alcohol-based resin as anchoring coating 32a, methods for forming anchoring coating 32a include coating with polyvinyl alcohol-based resin solution, multilayer extrusion, etc.

[0126] (Evaporated layer 32b)

[0127] The vapor-deposited layer 32b is a layer (barrier layer) exhibiting barrier properties against water vapor and oxygen, and comprises at least one of a metal and an inorganic oxide. The vapor-deposited layer 32b is disposed directly above the anchoring coating 32a. The vapor-deposited layer 32b can be a single layer or a multilayer structure. Therefore, the vapor-deposited layer 32b comprises at least one of a metal vapor-deposited layer and an inorganic oxide layer. When the vapor-deposited layer 32b comprises a metal vapor-deposited layer, examples of metals included in the metal vapor-deposited layer include aluminum and stainless steel. When the vapor-deposited layer 32b comprises an inorganic oxide layer, examples of inorganic oxides included in the inorganic oxide layer include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoint of transparency and barrier properties, the inorganic oxide can be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. Furthermore, from the viewpoint of excellent tensile elongation during processing, the inorganic oxide layer is preferably a layer using silicon oxide. By using an inorganic oxide layer, high barrier properties can be achieved with a very thin layer that does not affect the reusability of the laminate 1.

[0128] When the vapor-deposited layer 32b is an inorganic oxide layer using silicon oxide, the O / Si ratio of this inorganic oxide layer is preferably 1.7 or higher. When the O / Si ratio is 1.7 or higher, the content of metallic Si is suppressed, and good transparency is easily obtained. In addition, the O / Si ratio is preferably 2.0 or lower. When the O / Si ratio is 2.0 or lower, it is possible to prevent the crystallinity of SiO from becoming too high and the inorganic oxide layer from becoming too hard, and good tensile strength can be obtained. As a result, cracks can be suppressed in the inorganic oxide layer when the barrier coating 32c is laminated. In addition, after being formed into a packaging bag, the first substrate layer 10 may sometimes shrink due to the heat during boiling or steaming treatment, but with an O / Si ratio of 2.0 or lower, the inorganic oxide layer easily follows the above shrinkage, and the reduction of barrier properties can be suppressed. From the viewpoint of obtaining these effects more fully, the O / Si ratio of the inorganic oxide layer is preferably 1.75 or higher and 1.9 or lower, more preferably 1.8 or higher and 1.85 or lower.

[0129] When the vapor-deposited layer 32b is an inorganic oxide layer using silicon dioxide, the O / Si ratio of this inorganic oxide layer can be determined by X-ray photoelectron spectroscopy (XPS). For example, the measuring device is an X-ray photoelectron spectroscopy analyzer (manufactured by Nippon Electron Ltd., trade name: JPS-90MXV), using a non-monochromatic MgKα (1253.6 eV) X-ray source, and the measurement is performed with an X-ray output power of 100 W (10 kV-10 mA). In the quantitative analysis used to determine the O / Si ratio, relative sensitivity factors of 2.28 for O 1s and 0.9 for Si 2p can be used respectively.

[0130] The thickness of the vapor-deposited layer 32b is, for example, 5 nm to 80 nm. When the thickness of the vapor-deposited layer 32b is 5 nm or more, sufficient water vapor barrier properties can be obtained. Furthermore, when the thickness of the vapor-deposited layer 32b is 80 nm or less, cracking caused by deformation due to internal stress of the film can be suppressed, and the reduction in water vapor barrier properties can be prevented. It should be noted that when the thickness of the vapor-deposited layer 32b exceeds 80 nm, the cost tends to increase due to the increased material usage and prolonged film formation time, therefore it is not preferred from an economic point of view. From the same perspective, the thickness of the vapor-deposited layer 32b can be 20 nm to 40 nm.

[0131] The vapor-deposited layer 32b can be formed, for example, by vacuum deposition. In vacuum deposition, physical vapor deposition (PVD) or chemical vapor deposition (CVD) methods can be used. Examples of PVD methods include vacuum evaporation, sputtering, and ion plating, but are not limited to these. Examples of CVD methods include thermal CVD, plasma CVD, and photochemical CVD, but are not limited to these.

[0132] In the aforementioned vacuum film deposition methods, resistance heating vacuum evaporation, EB (Electron Beam) heating vacuum evaporation, induction heating vacuum evaporation, sputtering, reactive sputtering, dual magnetron sputtering, and plasma chemical vapor deposition (PECVD) are particularly preferred. However, considering productivity, vacuum evaporation is currently the optimal method. As the heating method for vacuum evaporation, any one of electron beam heating, resistance heating, or induction heating is preferred.

[0133] (Barrier coating 32c)

[0134] The barrier coating 32c is a gas barrier film layer (gas barrier coating layer) disposed on the vapor-deposited layer 32b. The barrier coating 32c is, for example, a layer formed using a gas barrier coating forming composition (hereinafter also referred to as a coating agent) containing at least one of the group consisting of a hydroxyl-containing polymer, a metal alkoxide, a silane coupling agent and their hydrolysis products.

[0135] From the viewpoint of more adequately maintaining the gas barrier properties after hot water treatment such as boiling, the coating agent preferably contains at least a silane coupling agent or its hydrolysis product, more preferably at least one selected from the group consisting of a hydroxyl-containing polymer, a metal alkoxide and its hydrolysis product, and a silane coupling agent or its hydrolysis product, and even more preferably contains a hydroxyl-containing polymer or its hydrolysis product, a metal alkoxide or its hydrolysis product, and a silane coupling agent or its hydrolysis product. The coating agent can be prepared, for example, by directly mixing a metal alkoxide and a silane coupling agent in a solution obtained by dissolving a water-soluble hydroxyl-containing polymer in an aqueous solvent (water or a water / alcohol mixture), or by mixing a product previously treated by hydrolyzing the metal alkoxide and the silane coupling agent.

[0136] The components contained in the coating agent used to form the barrier coating 32c are described in detail. Examples of hydroxyl-containing polymers used in the coating agent include polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. Among these, polyvinyl alcohol (PVA) is preferred because it exhibits particularly excellent gas barrier properties when used as the coating agent for the barrier coating 32c.

[0137] From the viewpoint of obtaining excellent gas barrier properties, the barrier coating 32c is preferably formed of a composition comprising at least one of the metal alkoxides and their hydrolysis products represented by the following general formula (I).

[0138] M(OR 1 ) m (R 2 ) n-m …(I)

[0139] In the above general formula (I), R 1 and R 2 Each is an independent monovalent organic group with 1 to 8 carbon atoms, preferably an alkyl group such as methyl or ethyl. M represents an n-valent metal atom such as Si, Ti, Al, or Zr. m is an integer from 1 to n. It should be noted that when multiple R groups are present... 1 Or R 2 In the case of R 1 Each other or R 2 They can be the same or different.

[0140] Specifically, examples of metal alkoxides include tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3]. Tetraethoxysilane and triisopropoxyaluminum are relatively stable in aqueous solvents after hydrolysis, and are therefore preferred.

[0141] Compounds represented by the following general formula (II) can be listed as silane coupling agents.

[0142] Si(OR 11 ) p (R 12 ) 3-p R 13 …(II)

[0143] In the above general formula (II), R 11 R represents alkyl groups such as methyl and ethyl. 12 R represents a monovalent organic group such as alkyl, aralkyl, aryl, alkenyl, alkyl substituted with acryloyloxy, or alkyl substituted with methacryloyloxy. 13 Let R represent a monovalent organic functional group, and p represent an integer from 1 to 3. It should be noted that when multiple R exist... 11 Or R 12 In the case of R 11 Each other or R 12 They can be the same or different. As a product of R... 13 The monovalent organic functional groups can be listed as glycidoxy, epoxy, mercapto, hydroxyl, amino, alkyl groups substituted with halogen atoms, or monovalent organic functional groups containing isocyanate groups.

[0144] Specifically, examples of silane coupling agents include vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropylmethyldimethoxysilane.

[0145] Alternatively, the silane coupling agent can also be a polymer formed by polymerizing a compound represented by the above general formula (II). As a polymer, a trimer is preferred, and more preferably 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate. This is a condensation polymer of 3-isocyanate-based alkylalkoxysilanes. It is known that this 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate is not chemically reactive in the isocyanate portion, but its reactivity is ensured by the polarity of the ureate portion. It is generally known as an adhesive enhancer, similar to 3-isocyanate-based alkylalkoxysilanes, when added to adhesives and the like. Therefore, by adding 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate to a hydroxyl-containing polymer, the water resistance of the gas-barrier coating can be improved through hydrogen bonding. 3-Isocyanate-based alkylalkoxysilanes are highly reactive and have low liquid stability. In contrast, 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate, due to the polarity of the ureate ester, is not water-soluble but is easily dispersed in aqueous solutions and can stably maintain liquid viscosity. Furthermore, 3-isocyanate-based alkylalkoxysilanes and 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate have equivalent water resistance.

[0146] 1,3,5-Tris(3-trialkoxysilylpropyl)isocyanurate can be produced by the thermal condensation of 3-isocyanopropylalkoxysilane, which may contain the starting material 3-isocyanopropylalkoxysilane, but this is not a particular problem. Further preferred is 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate, more preferably 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate. 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is practically advantageous due to the rapid hydrolysis of the methoxy group and the relatively inexpensive availability of propyl-containing compounds.

[0147] In addition, within the range that does not impair the air barrier properties, isocyanate compounds, or known additives such as dispersants, stabilizers, viscosity modifiers, and colorants may be added to the coating agent as needed.

[0148] The thickness of the barrier coating 32c is preferably 50 to 1000 nm, more preferably 100 to 500 nm. When the thickness of the barrier coating 32c is 50 nm or more, it tends to achieve more adequate gas barrier properties, while when it is 1000 nm or less, it tends to maintain adequate flexibility.

[0149] The coating liquid used to form the barrier coating 32c can be applied by methods such as dip coating, roller coating, gravure coating, reverse gravure coating, air knife coating, comma coating, mold coating, screen printing, spraying, and gravure offset coating. The coating film formed by applying this coating liquid can be dried by methods such as hot air drying, hot roller drying, high-frequency irradiation, infrared irradiation, UV irradiation, or combinations thereof.

[0150] The drying temperature of the coating can be set to, for example, 50–150°C, preferably 70–100°C. By setting the drying temperature within the above range, cracking in the vapor-deposited layer 32b and the barrier coating 32c can be further suppressed, resulting in excellent barrier properties.

[0151] The barrier coating 32c can be formed using a coating agent containing polyvinyl alcohol-based resins and silane compounds. Acid catalysts, base catalysts, photopolymerization initiators, etc., can be added to the coating agent as needed.

[0152] Polyvinyl alcohol-based resins are as described above. Additionally, examples of silane compounds include silane coupling agents, polysilazanes, and siloxanes; specifically, examples include tetramethoxysilane, tetraethoxysilane, epoxypropoxypropyltrimethoxysilane, acryloyloxypropyltrimethoxysilane, and hexamethyldisilazane.

[0153] [Sealing layer 50]

[0154] The sealing layer 50 is a layer in the laminate 1 that imparts a sealing property through heat sealing. From the viewpoint of reusability of the laminate 1, the sealing layer 50, like the first substrate layer 10, is a polyolefin film. In this embodiment, the sealing layer 50 is a resin layer having a single-layer structure and primarily composed of polypropylene, but it is not limited thereto. The sealing layer 50 may comprise a polypropylene film or may be composed of a polypropylene film.

[0155] Polypropylene films can be acid-modified polypropylene films obtained by grafting polypropylene with unsaturated carboxylic acids, anhydrides of unsaturated carboxylic acids, esters of unsaturated carboxylic acids, etc. Alternatively, homopolymer polypropylene resins (PP), propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-α-olefin copolymers, and other polypropylene-based resins can be used as polypropylene.

[0156] From the viewpoint of improving heat-sealing performance, the polypropylene film constituting the sealing layer 50 is preferably an unstretched polypropylene film.

[0157] Various additives such as flame retardants, slip agents, anti-blocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents can be added to the polypropylene film that constitutes the sealing layer 50.

[0158] The thickness of the sealing layer 50 is determined by the quality of the contents, the shape of the packaging bag, etc., and can be approximately 30 to 150 μm thick, or 50 to 80 μm thick.

[0159] While the reasoning for heating the sealing layer 50 at 128°C for 15 minutes is unclear, the opening height of the packaging bag can be easily obtained by thermal expansion on the MD and thermal contraction on the TD. From the same point of view, when the sealing layer 50 is heated at 128°C for 15 minutes, the thermal shrinkage rate of the MD calculated by the above formula (1) is preferably -1.0% or more, more preferably -0.5% or more, and preferably less than 0%.

[0160] When the sealing layer 50 is heated at 128°C for 15 minutes, the heat shrinkage rate of TD calculated by the above formula (2) is preferably 0% or more and preferably 1.0% or less.

[0161] As a lamination method for the sealing layer 50, it can be laminated by any of the following known methods: dry lamination method in which the film-like sealing layer composed of the above-mentioned polypropylene is bonded using an adhesive such as a one-component curing or two-component curing urethane adhesive; solventless lamination method in which the film-like sealing layer is bonded using a solventless adhesive; extrusion lamination method in which the above-mentioned polypropylene is heated and melted, extruded in a curtain shape, and bonded, etc.

[0162] Of the lamination methods described above, dry lamination is preferred due to its high tolerance to cooking treatments, especially hot water treatments at temperatures above 120°C. On the other hand, if the application involves processing packaging bags at temperatures below 85°C, there are no particular restrictions on the lamination method.

[0163] The above description illustrates a laminate according to one embodiment, but the laminate disclosed herein is not limited to the above embodiment. For example, the laminate may also include a printed layer.

[0164] [Printed layer]

[0165] The printed layer may be disposed on at least one surface of the first substrate layer 10. The printed layer is disposed in a position visible from the outside of the laminate 1 in order to display information related to the contents, identify the contents, improve concealment, or enhance the design of the packaging bag. There are no particular limitations on the printing method and printing ink; considerations such as the printability of the film, design aspects like color tone, adhesion, and safety as a food container can be taken into account when appropriately selecting from known printing methods and printing inks. For example, gravure printing, offset printing, gravure-offset printing, flexographic printing, and inkjet printing can be used. From the viewpoint of productivity and high pattern precision, gravure printing is preferred.

[0166] To improve the adhesion of the printed layer, various pretreatments such as corona treatment, plasma treatment, and flame treatment can be applied to the surface of the layer on which the printed layer is applied, or an easy-to-adhere coating can be applied.

[0167] Furthermore, the laminate of this disclosure may not include the anchoring coating 32a. The laminate of this disclosure may also not include the barrier coating 32c. The stacking order of the second substrate layer 31, the anchoring coating 32a, the vapor-deposited layer 32b, and the barrier coating 32c may also be interchanged. Additionally, the laminate of this disclosure may not include at least one of the first adhesive layer 20 and the second adhesive layer 40.

[0168] <Packaging>

[0169] The following describes a packaging body according to one embodiment. Figure 2 This is a schematic plan view of an example of a packaging body according to this embodiment. The packaging body 200 includes a packaging bag 100 and contents (not shown) contained within the packaging bag.

[0170] The packaging bag 100 is formed, for example, by merging two laminates 1 together with the sealing layers facing each other and heat-sealing the four sides.

[0171] The packaging bag 100 is a four-sided bag having a main body 101 for containing contents and a sealing portion 102 located at the end of the main body 101. The shape of the main body 101 is not particularly limited; for example, it may be rectangular when viewed from a predetermined direction. At least a portion of the outer surface of the main body 101 may be printed. The main body 101 may contain, for example, specific gases such as nitrogen in addition to the contents. The sealing portion 102 is a part of the sealing layer 50 of the laminate 1 that is adhered to other parts. In the sealing portion 102, the part of the sealing layer 50 of the laminate 1 is tightly sealed to the other parts. The sealing portion 102 is formed, for example, by heating and compressing (i.e., heat sealing) the part of the sealing layer 50 of the laminate 1 to the other parts, but is not limited to this method. For example, the sealing portion 102 may also be formed by cold sealing or the like.

[0172] The maximum opening heights H1 and H2 of the packaging body 200, measured through the following processes, meet the following conditions. By ensuring that the maximum opening heights H1 and H2 meet the following conditions, when the opening is positioned vertically downwards to discharge the contents, the opening of the packaging body 200 is not easily closed, resulting in excellent discharge performance.

[0173] 4mm≤H1

[0174] 6mm≤H2

[0175] (2a) The process of taking 20mm from the top of the packaging bag as the first position and the center of the packaging bag in the height direction as the second position, cutting the packaging bag from one side to the other at the first position, discharging the contents, and measuring the maximum opening height H1 at the first position while the packaging bag is placed on a horizontal platform.

[0176] (2b) After step (2a), the process of cutting the packaging bag from one side to the other at position 2, and measuring the maximum opening height H2 at position 2 while the packaging bag is placed on a horizontal platform.

[0177] exist Figure 2 In the diagram, the first position is represented by an imaginary line II, 20 mm from the top edge (L1). Figure 2 In the middle, the second position is represented by an imaginary line II-II, which is 70mm away from both the top and bottom ends. Figure 3 This is the end view of imaginary line II. (Example) Figure 3 As shown, the maximum opening height H1 is the maximum spacing between the inner edges of the sealing layers. The same applies to the maximum opening height H2. The numerical ranges of the maximum opening heights H1 and H2 can be the same as those of the maximum opening heights H1 and H2 of laminate 1.

[0178] The sealing width S of the packaging bag 100 can be, for example, 2 to 10 mm. The width W1 of the packaging bag 100 can be, for example, 80 to 150 mm. The height W2 of the packaging bag 100 can be, for example, 120 to 200 mm.

[0179] The packaging body 200 can be subjected to heat treatment at temperatures above 80°C, above 120°C, or below 135°C. Examples of heat treatments include steaming and boiling.

[0180] Cooking is a method of sterilization used to preserve food and pharmaceuticals by heating and pressurizing microorganisms such as molds, yeasts, and bacteria. Typically, packaging bags containing food are heated and pressurized at 105–140°C, 0.15–0.30 MPa, for 10–120 minutes. Cooking apparatus includes steam-type (using heated steam) and hot water-type (using pressurized heated water), depending on the sterilization requirements of the food or other contents. Boiling is a method of moist heat sterilization used to preserve food and pharmaceuticals. Typically, depending on the contents, packaging bags containing food are moist heat sterilized at 60–100°C, atmospheric pressure, for 10–120 minutes. Boiling typically uses a hot water bath at temperatures below 100°C. Methods include batch processing (immersing in a hot water bath at a specific temperature for a certain time and then removing the product) and continuous processing (processing through a channel in a hot water bath).

[0181] Examples of contents that can be included include food and pharmaceuticals. Because the packaging bag 100 has excellent drainage properties, the contents can also contain water that is normally difficult to drain. Based on the total amount of contents, the water content can be, for example, 60% by mass or more, preferably 70% by mass or more, and more preferably 75% by mass or more. Examples of water-containing contents that can be included include cooked foods such as soups and pasta sauces, and pet food.

[0182] The above description describes a packaging body according to one embodiment, but the packaging body disclosed herein is not limited to the above embodiment. For example, the packaging bag may be a stand-up pouch, a two-side bag, a three-side bag, a gusseted bag, or a corner-supported bag. The packaging bag may also lack a resealable portion and a slit. The packaging bag may also have a slit. The slit may be V-shaped, U-shaped, or I-shaped, etc. Alternatively, a scar group may be formed instead of a slit.

[0183] Example

[0184] The embodiments of this disclosure are described in detail below. However, this disclosure is not limited to the following embodiments.

[0185] <Preparation of Materials>

[0186] The following materials were prepared as the first substrate layer, the second substrate layer, the sealing layer, and the adhesive.

[0187] [First substrate layer]

[0188] • OPP1A: Biaxially stretched polypropylene film (20μm thickness)

[0189] • OPP1B: Biaxially stretched polypropylene film (20μm thickness)

[0190] • OPP1C: Biaxially stretched polypropylene film (20μm thickness)

[0191] • PET: Polyethylene terephthalate film (12μm thick)

[0192] [Second substrate layer]

[0193] • OPP2A: Biaxially stretched polypropylene film (20μm thickness)

[0194] • OPP2B: Biaxially stretched polypropylene film (20μm thickness)

[0195] (Sealing layer)

[0196] • CPP-A: Unstretched polypropylene film (60μm thickness)

[0197] • CPP-B: Unstretched polypropylene film (80μm thickness)

[0198] • CPP-C: Unstretched polypropylene film (60μm thickness)

[0199] • CPP-D: Unstretched polypropylene film (40μm thickness)

[0200] • CPP-E: Unstretched polypropylene film (70μm or 80μm thickness)

[0201] (Adhesive)

[0202] • Manufactured by Mitsui Chemicals Co., Ltd., trade name: Main agent A525 / Curing agent A52

[0203] [Preparation of Anchoring Coating Agent]

[0204] Acrylic polyol and toluene diisocyanate were mixed in such a manner that the number of NCO groups in toluene diisocyanate was equal to the number of OH groups in acrylic polyol, and diluted with ethyl acetate so that the total solids content (total amount of acrylic polyol and toluene diisocyanate) was 5% by mass. In the diluted mixture, β-(3,4-epoxycyclohexyl)trimethoxysilane was further added in such a manner that it was 5 parts by mass relative to 100 parts by mass of the total amount of acrylic polyol and toluene diisocyanate, and the mixture was then combined to prepare the anchoring coating agent.

[0205] [Preparation of coating liquid for barrier coating]

[0206] A coating liquid for barrier coating was prepared by mixing liquids A, B and C in a mass ratio of 65 / 25 / 10, respectively.

[0207] Solution A: Add 72.1g of 0.1N hydrochloric acid to 17.9g of tetraethoxysilane (Si(OC2H5)4) and 10g of methanol, stir for 30 minutes to hydrolyze it, and obtain a hydrolysate solution with a solid content of 5% by mass (converted to SiO2).

[0208] Solution B: 5% by mass polyvinyl alcohol in water / methanol solution (water:methanol mass ratio is 95:5).

[0209] Solution C: A hydrolyzed solution obtained by diluting 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate to a solid content of 5% by mass using a mixture of water and isopropanol (water:isopropanol mass ratio of 1:1).

[0210] <Manufacturing of the Gas Barrier Film (Intermediate Layer)>

[0211] (Examples 1-5, Comparative Examples 1, 2, 5, 6)

[0212] The materials shown in Table 1 were used as the second substrate layer. The above-mentioned anchoring coating composition was applied to the corona-treated surface of the second substrate layer using a gravure roller coating method, and then dried and cured at 60°C to form a coating with a coating amount of 0.1 g / m². 2 An anchoring coating composed of polyester-based polyurethane resin.

[0213] Next, a transparent inorganic oxide layer (silicon oxide vapor deposition layer) consisting of silicon oxide with a thickness of 30 nm was formed using a vacuum evaporation apparatus based on electron beam heating. As the silicon oxide vapor deposition layer, the type of evaporation material was adjusted to form an O / Si ratio of 1.8. The O / Si ratio was measured using an X-ray photoelectron spectroscopy analyzer (manufactured by Nippon Electron Ltd., trade name: JPS-90MXV), with a non-monochromatic MgKα (1253.6 eV) X-ray source and an X-ray output power of 100 W (10 kV-10 mA). In the quantitative analysis used to determine the O / Si ratio, relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p were used.

[0214] Next, the above-mentioned barrier coating liquid was applied to the inorganic oxide layer using a gravure roller coating method. The coating was then dried in an oven under a tension of 20 N / m and a drying temperature of 120°C, forming an outer coating with a thickness of 0.3 μm. Thus, a gas barrier film with a laminated structure of a second substrate layer / anchoring coating / evaporated layer / outer coating was obtained.

[0215] <Fabrication of Layered Structures>

[0216] Based on the combinations of layers shown in Table 1, laminates of various embodiments and comparative examples were manufactured. The method for manufacturing the laminates is described below.

[0217] (Examples 1-5, Comparative Examples 1, 2, 5, 6)

[0218] A first substrate layer is laminated onto the surface of the outer coating side of the gas barrier film using a dry lamination method via an adhesive. A sealing layer is similarly laminated onto the other surface of the second substrate layer of the gas barrier film. This creates a laminate with a structure consisting of a first substrate layer / adhesive layer / outer coating / evaporated layer / anchoring coating / second substrate layer / adhesive layer / sealing layer.

[0219] (Compare Examples 3 and 4)

[0220] An AL foil (thickness: 10 μm, MD heat shrinkage rate: 0%, TD heat shrinkage rate: 0%) was prepared. A first substrate layer was laminated onto one surface of the AL foil using an adhesive via dry lamination. A sealing layer was similarly laminated onto the surface of the AL foil opposite to the surface with the first substrate layer. Thus, a laminate with a structure of first substrate layer / adhesive layer / AL foil layer / adhesive layer / sealing layer was manufactured.

[0221] <Ring stiffness value>

[0222] The laminates of each embodiment and comparative example were subjected to a cooking treatment by heating them at a temperature of 128°C for 15 minutes and a pressure of 0.3 MPa. The ring stiffness value was measured for the heated laminates. A ring stiffness tester manufactured by Toyo Seiki Co., Ltd. was used for the measurement. A test film with a TD of 15 mm and an MD of 200 mm was prepared from the heated laminate. A ring with a size of 85 mm × 15 mm was formed by fixing both ends of the test film with a chuck. The ring was compressed using an indenter at a compression speed of 3.3 mm / min, a compression time of 3 seconds, and a compression distance of 20 mm, and the load on the indenter was measured. The maximum load measured in this test was used as the ring stiffness value. It should be noted that the compression distance represents the distance when the indenter is closest to the chuck. The results are shown in Table 2.

[0223] <Determination of maximum opening heights H1 and H2>

[0224] The maximum opening heights H1 and H2 were measured using the following procedures. The maximum opening height H1 was calculated as the average of the values ​​measured for three laminates. Similarly, the maximum opening height H2 was calculated as the average of the values ​​measured for three laminates. The results are shown in Table 2.

[0225] (1a) The procedure of preparing two laminates with a width of 90 mm and a length of 140 mm as test pieces.

[0226] (1b) The process of overlapping two test pieces with the sealing layers facing each other and sealing three sides with a sealing width of 5 mm to form a bag.

[0227] (1c) The procedure of injecting 70g of water into the top of the bag and then sealing the top with a sealing width of 5mm to obtain the test specimen.

[0228] (1d) Procedure of heating the test specimen at a temperature of 128°C for 15 minutes and a pressure of 0.3 MPa.

[0229] (1e) After step (1d), at the first position 20mm from the top of the bag, cut the bag from one side to the other, drain the water, and then measure the maximum opening height H1 at the first position while the bag is placed on a water platform.

[0230] (1f) After step (1e), at a second position 50 mm from the first position, cut the bag from one side to the other, and measure the maximum opening height H2 at the second position while the bag is placed on a horizontal platform.

[0231] In step (1b), a pulse sealing machine was used. In step (1c), after water was injected into the bag, the air inside the bag was removed while the upper part of the bag was folded, and the upper end was sealed in this state. In step (1d), the test body was heated with the main surface horizontal. Heating was performed by spraying water onto the test body. In step (1e), after draining the water, the inside of the bag was gently wiped with Kimwipes to remove moisture. In addition, before measuring the maximum opening height H1, with the bag placed on a horizontal platform, the main surface of the bag was pressed from the bottom to the top with the palm of the hand with a force of 2 to 3 kg. In step (1f), before measuring the maximum opening height H2, with the bag placed on a horizontal platform, the main surface of the bag was pressed from the bottom to the top with the palm of the hand with a force of 2 to 3 kg.

[0232] <Determination of shrinkage rate of the first substrate layer, second substrate layer, sealing layer, and laminate>

[0233] The thermal shrinkage rates of the first substrate layer, second substrate layer, sealing layer, and laminate of each embodiment and comparative example were measured according to the following steps. The results are shown in Table 1.

[0234] (1) such as Figure 4 As shown, a 200mm × 200mm section is cut from the layer or laminate that is to be measured, and this section is used as the measurement sample 500.

[0235] (2) such as Figure 4 As shown, two straight lines L1 and L2 with a length of more than 120 mm are drawn parallel to the TD of the measured sample 500, with an interval of 100 mm.

[0236] (3) such as Figure 4 As shown, two straight lines L3 and L4, with a length of more than 120 mm, parallel to the MD of the measured sample 500, are drawn with a 100 mm interval.

[0237] (4) such as Figure 4As shown, markings N1 to N7 are drawn at 7 points with 20mm intervals on line L1. The same markings are drawn on lines L2 to L4. When each of the markings N1 to N7 on line L1 is connected to each of the markings N1 to N7 on line L2 with a straight line, the positions of the markings on lines L1 and L2 are aligned with this straight line being parallel to MD. Similarly, when each of the markings N1 to N7 on line L3 is connected to each of the markings N1 to N7 on line L4 with a straight line, the positions of the markings on lines L3 and L4 are aligned with this straight line being parallel to TD.

[0238] (5) The sample was heated at 128℃ for 15 minutes and 0.3MPa. After heating, the sample was placed at room temperature (25℃) for 30 minutes.

[0239] (6) Before and after heating, measure the straight-line distance between the scale N1 (intersection of L1 and N1) of straight line L1 and the scale N1 (intersection of L2 and N1) of straight line L2 as the MD length, and calculate the MD heat shrinkage rate using the following formula (1). Similarly, calculate the MD heat shrinkage rate at each position of scale N1 to N7, and take their average value as the MD heat shrinkage rate of the measured sample 500.

[0240] MD heat shrinkage rate (%) = (MD length before heating - MD length after heating) / MD length before heating × 100… (1)

[0241] (7) Before and after heating, measure the straight-line distance between the scale N1 (intersection of L3 and N1) of straight line L3 and the scale N1 (intersection of L4 and N1) of straight line L4 as the TD length, and calculate the TD heat shrinkage rate using the following formula (2). Similarly, calculate the TD heat shrinkage rate at each position of scale N1 to N7, and take their average value as the TD heat shrinkage rate of the measured sample 500.

[0242] TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100… (2)

[0243] <Excretion>

[0244] Prepare two laminated sheets, each 90mm wide and 140mm long, as test pieces. Overlap the two test pieces with the sealing layers facing each other. Seal three sides of the test pieces using a pulse sealing machine (5mm sealing width) to obtain a packaging bag. Fill the top of the packaging bag with approximately 50g of wet pet food. Seal the top of the packaging bag using a pulse sealing machine (5mm sealing width). This yields a package containing the packaging bag and the contents (wet pet food).

[0245] The packaging was heated at 128°C for 15 minutes and at a pressure of 0.3 MPa. Heating was performed by spraying water onto the packaging. An opening was created by cutting the bag from one side to the other at a position 20 mm from the top of the heated bag. The maximum opening height was measured. With the opening vertically downward, the bag was held for 30 seconds to expel the contents. After 15 seconds, both sides of the bag were pinched and pressed inwards. The amount of contents expelled within 30 seconds was measured. The discharge rate was calculated using the following formula.

[0246] Discharge rate (%) = Amount of contents discharged (g) / Amount of contents filled (g) × 100

[0247] The maximum opening height and discharge rate of the opening were evaluated according to the following criteria. The results are shown in Table 2.

[0248] (Benchmark)

[0249] A: Maximum opening height exceeds 25mm and discharge rate exceeds 90%.

[0250] B: Maximum opening height is 20mm or more but less than 25mm and discharge rate exceeds 90%.

[0251] C: Besides A and B evaluations

[0252] <Operability when opening packaging bags>

[0253] Prepare two laminated sheets, each 90mm wide and 140mm long, as test pieces. Overlap the two test pieces with the sealing layers facing each other. Seal three sides of the test pieces using a pulse sealing machine (5mm sealing width) to obtain a packaging bag. Fill the top of the packaging bag with approximately 50g of wet pet food. Seal the top of the packaging bag using a pulse sealing machine (5mm sealing width). This yields a package containing the packaging bag and the contents (wet pet food).

[0254] The packaging was heated at 128°C for 15 minutes and 0.3 MPa. Heating was performed by spraying water onto the packaging. At the first position, 20 mm from the top of the heated packaging, an opening was formed by cutting from one side of the bag to the other. The operability of opening the packaging was evaluated according to the following criteria (A-D): the ease of applying and reducing force when pressing the sealing parts at both ends of the packaging towards each other, and the ease of maintaining the opening shape. The evaluation was conducted according to the following criteria. The results are shown in Table 2.

[0255] (Benchmark)

[0256] A: Use light force to open the opening; it's easier to keep it open.

[0257] B: The opening is easy to open and easy to maintain.

[0258] C: The packaging bag is sturdy, making it difficult to open the opening, but it is easy to keep the opening closed.

[0259] D: The opening is deformed (torsional) and difficult to open or maintain.

[0260]

[0261]

[0262] Explanation of symbols

[0263] 1…Laminated body, 30…Intermediate layer, 50…Sealing layer, 100…Packaging bag, 200…Packaging body.

Claims

1. A laminated body having a stacked structure comprising the following layers in sequence: Substrate layer intermediate layer, and Sealing layer, The maximum opening heights H1 and H2, measured through the following processes, meet the following conditions: 4mm≤H1 6mm≤H2 The maximum opening heights H1 and H2 are determined through the following process: (1a) The process of preparing two sheets of the laminate with a width of 90 mm and a length of 140 mm as test pieces; (1b) The process of overlapping the two test pieces with the sealing layers facing each other and sealing the three sides with a sealing width of 5 mm to form a bag; (1c) The process of injecting 70g of water into the upper end of the bag and sealing the upper end with a sealing width of 5mm to obtain the test body; (1d) The procedure of heating the test specimen at a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa; (1e) After step (1d), at a first position 20 mm from the upper end of the bag, the bag is cut from one side to the other to drain the water, and the maximum opening height H1 at the first position is measured while the bag is placed on a water platform; and (1f) After step (1e), at a second position 50 mm from the first position, the bag is cut from one side to the other, and the maximum opening height H2 at the second position is measured while the bag is placed on a horizontal platform. The ring stiffness of the laminate after heating at 128°C for 15 minutes is above 80mN and below 220mN.

2. The laminated body according to claim 1, wherein, When heated at 128℃ for 15 minutes, the MD heat shrinkage rate calculated by formula (1) is more than 1.0% and less than 3.0%, and the TD heat shrinkage rate calculated by formula (2) is more than 1.0% and less than 3.0%. 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 laminated body according to claim 1, wherein, When heated at 128°C for 15 minutes, the sealing layer thermally expands on MD and thermally shrinks on TD.

4. The laminated body according to claim 1, wherein, The substrate layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the following formula (1) is set as S1. MD And the thermal shrinkage rate of TD obtained by the following equation (2) is set as S1. TD At that time, S1 MD With S1 TD The difference (S1) MD -S1 TD () Greater than 0% and less than 5% 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 laminated body according to claim 1, wherein, The intermediate layer has a second substrate layer. The second substrate layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate of MD calculated by the following formula (1) is set as S2. MD And the thermal shrinkage rate of TD obtained by the following equation (2) is set as S2. TD At that time, S2 MD With S2 TD The difference (S2) MD -S2 TD () Greater than 0% and less than 5% 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: 4mm≤H1≤7mm 6mm≤H2≤9mm.

7. The laminated body according to claim 1, wherein, The substrate layer, the intermediate layer, and the sealing layer comprise polypropylene resin. The total mass percentage of polypropylene resin in this laminate is over 90% by mass.

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

9. The packaging bag according to claim 8, for use in carrying out heat treatment at 120°C or higher.

10. A packaging body, comprising: Packaging bags, and The contents contained within the packaging bag, The packaging bag is formed using a laminated structure. The laminate has a stacked structure comprising a substrate layer, an intermediate layer, and a sealing layer in sequence. The maximum opening heights H1 and H2, measured through the following processes, meet the following conditions: 4mm≤H1 6mm≤H2 The maximum opening heights H1 and H2 are determined through the following process: (2a) A process of cutting the packaging bag from one side to the other at the first position, with 20mm from the top of the packaging bag as the first position and the center of the packaging bag in the height direction as the second position, discharging the contents, and measuring the maximum opening height H1 at the first position while the packaging bag is placed on a horizontal platform; and (2b) After step (2a), the packaging bag is cut from one side to the other at the second position, and the maximum opening height H2 at the second position is measured while the packaging bag is placed on a horizontal platform. The ring stiffness of the laminate after heating at 128°C for 15 minutes is above 80mN and below 220mN.

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