Laminate, packaging bag and packaging body

Abstract

A laminate having a laminated structure including, in this order, a base layer, an intermediate layer, and a sealant layer, wherein the maximum opening heights H1 and H2 measured through a specified process satisfy the following conditions, and the loop stiffness value after heating at 128°C for 15 minutes is 80 mN or more and 220 mN or less. 4mm≦H1 6mm≦H2

Description

[Technical field]

[0001] The present disclosure relates to a laminate, a packaging bag, and a packaging body. [Background technology]

[0002] Laminates are widely used as packaging materials for foods, medicines, etc., which are subjected to heat sterilization such as boiling, retort, etc. Known laminates include a biaxially oriented PET (polyethylene terephthalate) film having excellent heat resistance and toughness, and a polyolefin film such as polyethylene or polypropylene as a sealant layer (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-178357 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, packaging materials are required to allow the contents contained therein to be easily discharged, and there is room for improvement in terms of dischargeability of conventional laminates.

[0005] Furthermore, packaging materials are required to have excellent handleability when opened.

[0006] One aspect of the present disclosure provides a packaging bag and a package that are excellent in discharging property and handling property when opened. Another aspect of the present disclosure provides a laminate useful for producing such a packaging bag and a package. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure provides the following laminate, packaging bag, and packaging body. [1] A substrate layer; The middle class, A sealant layer; A laminate having a laminate structure comprising, in this order, The maximum opening heights H1 and H2 measured through the following process must meet the following conditions: 4mm≦H1 6mm≦H2 The above maximum opening heights H1 and H2 are (1a) preparing two of the above laminates as test pieces each having a width of 90 mm and a length of 140 mm; (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 into 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) heating the test specimen at a temperature of 128° C. for 15 minutes under a pressure of 0.3 MPa; (1e) after the step (1d), cutting the bag from one side to the other side at a first position 20 mm from the top end of the bag, draining the water, and then measuring the maximum opening height H1 at the first position while the bag is placed on a horizontal table; (1f) after the step (1e), cutting the bag from one side to the other side at a second position 50 mm from the first position, and measuring the maximum opening height H2 at the second position while the bag is placed on a horizontal table; It is 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 [1], wherein when heated at 128°C for 15 minutes, the laminate has an MD heat shrinkage calculated by the following formula (1) of 1.0% or more and 3.0% or less, and a TD heat shrinkage calculated by the following formula (2) of 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 MD and thermally shrinks in TD. [4] The above base layer is heated at 128°C for 15 minutes, and the MD heat shrinkage rate calculated by the following formula (1) is S1 MD The thermal shrinkage rate of TD calculated by (2) below is S1 TD Then, S1 MD and S1 TD Difference from (S1 MD -S1 TD ) is more than 0% and 5% 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) [5] The intermediate layer has a second base material layer, and the second base material layer is heated at 128°C for 15 minutes, and the MD heat shrinkage rate calculated by the following formula (1) is S2 MD The thermal shrinkage rate of TD calculated by the following formula (2) is S2 TD Then, S2 MD and S2 TD Difference from (S2 MD -S2 TD ) is more than 0% and 5% 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) [6] The laminate according to any one of [1] to [5], wherein the maximum opening heights H1 and H2 satisfy the following conditions: 4mm≦H1≦7mm 6mm≦H2≦9mm [7] The laminate according to any one of [1] to [6], wherein the base layer, the intermediate layer and the sealant layer contain a polypropylene-based resin, and the total mass ratio of the polypropylene-based resin in the laminate is 90 mass% or more. [8] A packaging bag formed using the laminate according to any one of [1] to [7]. [9] The packaging bag according to any one of [1] to [8], which is used for applications requiring heat treatment at 120°C or higher.

[10] A packaging bag; Contents contained in the packaging bag; and Equipped with The packaging bag is formed using a laminate, The laminate has a laminate structure including a base layer, an intermediate layer, and a sealant layer in this order; The maximum opening heights H1 and H2 measured through the following process must meet the following conditions: 4mm≦H1 6mm≦H2 The above maximum opening heights H1 and H2 are (2a) a step of defining a first position as 20 mm from the top end of the packaging bag, defining a second position as the center of the packaging bag in the height direction, cutting the packaging bag from one side to the other side at the first position, discharging the contents, and then measuring a maximum opening height H1 at the first position while the packaging bag is placed on a horizontal table; (2b) after the step (2a), cutting the packaging bag from one side to the other side at the second position and measuring the maximum opening height H2 at the second position while the packaging bag is placed on a horizontal table; It is measured through The package has a loop stiffness value of 80 mN or more and 220 mN or less after heating the laminate at 128°C for 15 minutes. Effect of the Invention

[0008] According to one aspect of the present disclosure, there is provided a packaging bag and a package having excellent discharging properties and excellent handling properties when opened. According to another aspect of the present disclosure, there is provided a laminate useful for producing such a packaging bag and a package. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic cross-sectional view showing a laminate according to one embodiment. [Diagram 2] FIG. 2 is a schematic front view of an example of a packaging body. [Diagram 3] FIG. 3 is an end view taken along the imaginary line II in FIG. [Figure 4] FIG. 4 is a schematic diagram showing a method for measuring the thermal shrinkage rate upon heating. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described. Note that the same components are given the same reference numerals and duplicated explanations will be omitted. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown in the drawings.

[0011] <Laminate> Hereinafter, a laminate according to an embodiment will be described. FIG. 1 is a schematic cross-sectional view showing a laminate according to this embodiment. The laminate 1 has a laminate structure including a first base 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. When the maximum opening heights H1 and H2 satisfy the following conditions, the opening of a packaging bag obtained using the laminate 1 is difficult to close when the opening is placed at the lower part in the vertical direction to discharge the contents. Therefore, the packaging bag has excellent dischargeability even without providing irregularities or the like for promoting discharge of the contents on the surface of the sealant layer (innermost layer) of the laminate 1 by additional processing or the like. 4mm≦H1 6mm≦H2

[0012] (1a) A process of preparing two laminates with a width of 90 mm and a length of 140 mm as test pieces. (1b) A process in which two test pieces are stacked with the sealant layers facing each other and three sides are sealed with a seal width of 5 mm to form a bag. (1c) A process in which 70 g of water is poured into the top of the bag, and then the top is sealed with a seal width of 5 mm to obtain a test specimen. (1d) A process of heating the test specimen under conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa. (1e) After the step (1d), a step of cutting the bag from one side to the other side at a first position 20 mm from the top end of the bag, draining the water, and then measuring the maximum opening height H1 at the first position while the bag is placed on a horizontal table. (1f) After the (1e) steps, a step of cutting the bag from one side to the other side at a second position 50 mm from the first position and measuring the maximum opening height H2 at the second position while the bag is placed on a horizontal table.

[0013] The maximum opening height H1, H2 is the maximum spacing between the inner edges of the sealant layers.

[0014] The maximum opening height H1 is preferably 4.3 mm or more, and more preferably 5.0 mm or more, because this provides better dischargeability. 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] The maximum opening height H2 is preferably 6.3 mm or more, and more preferably 7.0 mm or more, because air can easily enter the entire main body of the packaging bag and the contents located at the four corners of the main body can be more easily separated. 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, 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 MD heat shrinkage rate calculated by the following formula (1) is preferably 1.0% or more, and more preferably 1.8% or more, because the resulting packaging bag opens sufficiently and has better discharging properties. When the laminate 1 is heated at 128°C for 15 minutes, the MD heat shrinkage rate calculated by the following formula (1) is preferably 3.0% or less, from the viewpoint of suppressing poor appearance and poor conveyance. When the laminate 1 is heated at 128°C for 15 minutes, the MD heat shrinkage rate 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 TD heat shrinkage rate calculated by the following formula (2) is preferably 1.0% or more, and more preferably 1.8% or more, because the resulting packaging bag opens sufficiently and has better discharging properties. When the laminate 1 is heated at 128°C for 15 minutes, the TD heat shrinkage rate calculated by the following formula (2) is preferably 3.0% or less, from the viewpoint of suppressing poor appearance and poor conveyance caused by shrinkage during bag making. When the laminate 1 is heated at 128°C for 15 minutes, the TD heat shrinkage rate 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 layer and the sealant layer, and TD is the transverse direction. The orientation angle of the film can be measured using, for example, a retardation measuring device (product 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, even more preferably 150 mN or less, even more preferably 130 mN or less, and particularly preferably 105 mN or less. When the loop stiffness value is within this range, the packaging bag has excellent handleability when opened. When the loop stiffness value is 80 mN or more, when the packaging bag is pinched by both hands at both sides and pushed toward the center of the packaging bag to discharge the contents, the packaging bag is less likely to twist (twist), making it easy to open and easy to maintain the opened shape. Therefore, the packaging bag tends to have better dischargeability. When the loop stiffness value is 150 mN or less, the packaging bag is easily pinched by both hands at both sides and pushed toward the center of the packaging bag. Therefore, the packaging bag tends to be easy to open stably and has better dischargeability. In addition, the packaging bag can be easily opened with a light force and can easily maintain the opened shape. The loop stiffness value of the laminate 1 after heating at 128°C for 15 minutes may be 80 mN to 220 mN, 80 mN to 170 mN, 80 mN to 150 mN, 80 mN to 130 mN, 80 mN to 105 mN, 90 mN to 220 mN, 90 mN to 170 mN, 90 mN to 150 mN, 90 mN to 130 mN, or 90 mN to 105 mN. The loop stiffness value can be measured by the method of the examples described later.

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

[0023] The total mass ratio of the polypropylene-based resin in the laminate 1 is preferably 90 mass% or more based on the total amount of the laminate 1, because the laminate 1 is a mono-material 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 mass% or more, or may be 95 mass% or more based on the total amount of the laminate 1.

[0024] Each layer of the laminate 1 will now be described in detail.

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

[0026] From the viewpoint of recycling suitability of the laminate 1, the first base layer 10 is, for example, a polyolefin film. The first base layer 10 may contain a polypropylene film or 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. In addition, as the polypropylene, a polypropylene-based resin such as a homopolypropylene resin (PP), a propylene-ethylene random copolymer, a propylene-ethylene block copolymer, or a propylene-α-olefin copolymer may be used.

[0027] The polypropylene film constituting the first base layer 10 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent.

[0028] The polypropylene film constituting the first base layer 10 may be a stretched film or a non-stretched film. Since the polypropylene film has better dischargeability, it is preferable that the polypropylene film is a stretched polypropylene film.

[0029] When the first base layer is heated at 128° C. for 15 minutes, the MD heat shrinkage 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, in order to provide better discharging properties. From the viewpoint of handling properties when opening the packaging bag, the MD heat shrinkage may be 5.0% or less.

[0030] When the first base layer is heated at 128° C. for 15 minutes, the TD heat shrinkage calculated by the above formula (2) is preferably more than 0%, more preferably 1.0% or more, and even more preferably 2.0% or more, in order to provide a better ejection property. From the viewpoint of handleability when opening the packaging bag, the TD heat shrinkage may be 3.0% or less.

[0031] The first base material layer is heated at 128°C for 15 minutes, and the MD heat shrinkage rate calculated by the above formula (1) is S1 MD The thermal shrinkage rate of TD calculated by the above formula (2) is S1 TD Then, S1 MD and S1 TD Difference from (S1 MD -S1 TD From the viewpoint of the tendency for the opening height to be high and for the dischargeability to be further improved, S1 is preferably more than 0%, more preferably 1% or more, and even more preferably 1.5% or more, and from the viewpoint of suppressing distortion of the packaging bag that causes packaging defects, S1 is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less. MD and S1 TD Difference from (S1 MD -S1 TD) may be greater than 0% and less than or equal to 5%, greater than 0% and less than or equal to 4%, greater than 0% and less than or equal to 3%, 1% or more and less than or equal to 5%, 1% or more and less than or equal to 4%, 1% or more and less than or equal to 3%, 1.5% or more and less than or equal to 5%, 1.5% or more and less than or equal to 4%, or 1.5% or more and less than or equal to 3%.

[0032] The first base material layer is heated at 128°C for 15 minutes, and the MD heat shrinkage rate calculated by the above formula (1) is S1 MD When the second base layer is heated at 128 ° C for 15 minutes, the MD heat shrinkage rate calculated by the above formula (1) is S2 MD Then, S1 MD and S2 MD Difference from (S1 MD -S2 MD ) is preferably more than 0%, more preferably 0.25% or more, and even more preferably 0.5% or more, from the viewpoint of suppressing the occurrence of cracks in the gas barrier layer due to differences in base material shrinkage, and is preferably 2.5% or less, more preferably 2.0% or less, and even more preferably 1.0% or less.

[0033] The first base material layer is heated at 128°C for 15 minutes, and the thermal shrinkage rate in TD calculated by the above formula (2) is S1 TD When the second base layer is heated at 128 ° C for 15 minutes, the thermal shrinkage rate in TD calculated by the above formula (2) is S2 TD Then, S1 TD and S2 TD Difference from (S1 TD -S2 TD ) is preferably more than 0%, more preferably 0.3% or more, and even more preferably 0.4% or more, from the viewpoint of suppressing the occurrence of cracks in the gas barrier layer due to differences in base material shrinkage, and is preferably 2.0% or less, more preferably 1.5% or less, and even more preferably 1.0% or less.

[0034] The lamination surface of the first base material layer 10 may be subjected to various pretreatments such as corona treatment, plasma treatment, and flame treatment, 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 bonds the first base material layer 10 and the intermediate layer 30. The second adhesive layer 40 is a layered member that bonds the intermediate layer 30 and the sealant layer 50. For example, polyester-isocyanate resin, urethane resin, polyether resin, etc. can be used as the adhesive material contained in the first adhesive layer 20 and the second adhesive layer 40. To use the packaging bag for retort applications, a two-liquid curing urethane adhesive that is resistant to retort can be preferably used. From the viewpoint of environmental consideration, the adhesive does not need to contain 3-glycidyloxypropyltrimethoxysilane (GPTMS). The first adhesive layer 20 and the second adhesive layer 40 do not need to contain chlorine. In this case, the first adhesive layer 20 and the second adhesive layer 40 can suppress coloring of the recycled resin after recycling and the generation of odor due to heat treatment. From the viewpoint of environmental consideration, the first adhesive layer 20 and the second adhesive layer 40 may be formed of a biomass material and may not contain a solvent.

[0036] The urethane adhesive contains polyol and polyisocyanate. When a urethane adhesive is used, the first adhesive layer 20 and the second adhesive layer 40 may contain polyurethane obtained by curing the urethane adhesive, or may contain an uncured urethane 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 base resin and a curing agent, respectively, to produce polyurethane.

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

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

[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 effectively suppressed. When the thickness of the first adhesive layer 20 is 10 μm or less, the laminate 1 can be easily made into a mono-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 effectively suppressed. When the thickness of the second adhesive layer 40 is 10 μm or less, the laminate 1 can be easily made into a mono-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] [Middle layer 30] 1, the intermediate layer 30 has a second base 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, from the second base layer 31 side, an anchor coat layer 32a, a deposition layer 32b, and a barrier coat layer 32c, in this order.

[0043] The thickness of the intermediate layer may be similar to that of the first substrate layer 10 .

[0044] (Second base layer 31) The thickness of the second base layer 31 may be the same as that of the first base layer 10. The second base layer 31 is, for example, a polyolefin film from the viewpoint of recycling suitability of the laminate 1. The second base layer 31 may contain a polypropylene film or may be made of a polypropylene film. The polypropylene film may be the same as that of the first base layer 10. The polypropylene film may be added with various additives similar to those of the first base layer 10. When the second base layer 31 contains an antiblocking agent, the addition of the antiblocking agent may be suppressed in order to improve the smoothness of the surface on the side where the deposition layer 32b is provided. The second base layer 31 may be subjected to various pretreatments similar to those of the first base layer 10, or a coating layer may be provided.

[0045] When the second base layer is heated at 128° C. for 15 minutes, the MD heat shrinkage 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, in order to provide a better dischargeability. The MD heat shrinkage may be 5.0% or less in terms of handleability when opening the packaging bag.

[0046] When the second base layer is heated at 128° C. for 15 minutes, the TD heat shrinkage calculated by the above formula (2) is preferably more than 0%, more preferably 1.0% or more, and even more preferably 2.0% or more, in order to provide a better dischargeability. The TD heat shrinkage may be 3.0% or less in terms of handleability when opening a packaging bag.

[0047] The second base layer is heated at 128°C for 15 minutes, and the MD heat shrinkage rate calculated by the above formula (1) is S2 MD The thermal shrinkage rate of TD calculated by the above formula (2) is S2 TD Then, S2 MD and S2 TD Difference from (S2 MD -S2 TDFrom the viewpoint of the tendency for the opening height to be high and for the dischargeability to be further improved, S2 is preferably more than 0%, more preferably 1% or more, and even more preferably 1.5% or more, and from the viewpoint of suppressing distortion of the packaging bag that causes packaging defects, S2 is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less. MD and S2 TD Difference from (S2 MD -S2 TD ) may be greater than 0% and less than or equal to 5%, greater than 0% and less than or equal to 4%, greater than 0% and less than or equal to 3%, 1% or more and less than or equal to 5%, 1% or more and less than or equal to 4%, 1% or more and less than or equal to 3%, 1.5% or more and less than or equal to 5%, 1.5% or more and less than or equal to 4%, or 1.5% or more and less than or equal to 3%.

[0048] (Anchor coat layer 32a) The anchor coat layer 32a functions as a layer capable of improving the adhesion performance of the deposition layer 32b on the second base layer 31, and is provided directly on the second base layer 31. Therefore, the anchor coat layer 32a is located between the second base layer 31 and the deposition layer 32b. By providing the anchor coat layer 32a, the smoothness of the surface on which the deposition layer 32b is provided in the intermediate layer 30 can be improved. In addition, the improved smoothness makes it easier to form the deposition layer 32b uniformly without defects, and makes it easier to exhibit high barrier properties. The anchor coat layer 32a can be formed, for example, using an anchor coat agent.

[0049] The anchor coating agent is preferably a urethane resin. Examples of the urethane resin include polyester polyurethane resin, polyether polyurethane resin, and acrylic polyurethane resin. From the viewpoint of heat resistance and interlayer adhesive strength, the anchor coating agent is preferably a polyester polyurethane resin and an acrylic polyurethane resin. In particular, in packaging materials that undergo boiling or retorting treatment, the anchor coating agent is more preferably an acrylic polyurethane resin.

[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. If the thickness of the anchor coat layer 32a is equal to or greater than the lower limit, a more sufficient interlayer adhesive strength tends to be obtained, whereas if the thickness is equal to or less than the upper limit, the desired gas barrier properties tend to be easily exhibited.

[0051] The method for applying the anchor coat layer 32a onto the second base layer 31 can be any known application method without particular limitation, and examples of such methods include immersion (dipping), spraying, coater, printer, brush, etc. Examples of the types of coaters and printers used in these methods and the application methods thereof include gravure coaters such as direct gravure, reverse gravure, kiss reverse gravure, and offset gravure, reverse roll coaters, microgravure coaters, coaters combined with chamber doctor, air knife coaters, dip coaters, bar coaters, comma coaters, die coaters, etc.

[0052] The coating amount of the anchor coat layer 32a is 1 m 2 after the anchor coat agent is applied and dried. 2 Mass per unit is 0.01 to 5 g / m 2 is preferably 0.03 to 3 g / m 2 It is more preferable that the thickness of the anchor coating agent is 1m after it is applied and dried. 2 When the mass per unit area is equal to or greater than the lower limit, the film tends to be sufficiently formed, whereas when the mass per unit area is equal to or less than the upper limit, the film tends to be sufficiently dried and the solvent is less likely to remain.

[0053] The method for drying the anchor coat layer 32a is not particularly limited, but 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. Furthermore, the drying conditions can be appropriately selected depending on the drying method, and 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 resin can be used instead of the polyurethane resin. The polyvinyl alcohol resin may be any resin having a vinyl alcohol unit formed by saponifying a vinyl ester unit, such as polyvinyl alcohol (PVA) or ethylene-vinyl alcohol copolymer (EVOH).

[0055] Examples of PVA include resins obtained by homopolymerizing vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versatate, followed by saponification. PVA may be modified PVA that has been copolymerized or post-modified. Modified PVA can be obtained, for example, by copolymerizing a vinyl ester with an unsaturated monomer copolymerizable with the vinyl ester, followed by saponification. Examples of unsaturated monomers copolymerizable with vinyl ester 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 undecylenic acid; nitriles such as acrylonitrile and methacrylonitrile; diacetone acrylamide, acrylonitrile, methacrylonitrile, and methacrylonitrile; and the like. amides such as arylamide and methacrylamide; olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid; vinyl compounds such as alkyl vinyl ethers, dimethylallyl vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinyl ethylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxane, glycerin monoallyl ether, and 3,4-diacetoxy-1-butene; vinylidene chloride, 1,4-diacetoxy-2-butene, and vinylene carbonate.

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

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

[0058] The degree of polymerization of EVOH is preferably 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 suitability is likely 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. The degree of saponification of EVOH may be 100 mol % or less, or 99.9 mol % or less. The degree of saponification of EVOH is determined by nuclear magnetic resonance (1H-NMR) measurement, from the peak area of ​​hydrogen atoms contained in the vinyl ester structure and the peak area of ​​hydrogen atoms contained in the vinyl alcohol structure.

[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. 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 can be maintained well under high humidity. On the other hand, when the ethylene unit content is 65 mol% or less, the gas barrier property can be improved. The ethylene unit content of EVOH can be determined by NMR method.

[0060] When a polyvinyl alcohol resin is used as the anchor coat layer 32a, the anchor coat layer 32a can be formed by coating a polyvinyl alcohol resin solution, multi-layer extrusion, or the like.

[0061] (Vapor deposited layer 32b) The 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 deposition layer 32b is provided directly on the anchor coat layer 32a. The deposition layer 32b may have a single-layer structure or a laminated structure. Therefore, the deposition layer 32b contains at least one of a metal deposition layer and an inorganic oxide layer. When the deposition layer 32b includes a metal deposition layer, examples of the metal included in the metal deposition layer include aluminum and stainless steel. When the deposition layer 32b includes an inorganic oxide layer, examples of the inorganic oxide included 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. In addition, the inorganic oxide layer is preferably a layer using silicon oxide from the viewpoint of excellent tensile stretchability during processing. By using an inorganic oxide layer, high barrier properties can be obtained with a very thin layer within a range that does not affect the recyclability of the laminate 1.

[0062] When the deposition layer 32b is an inorganic oxide layer using silicon oxide, the O / Si ratio of the inorganic oxide layer is preferably 1.7 or more. When the O / Si ratio is 1.7 or more, the content ratio of metal Si is suppressed, and good transparency is easily obtained. In addition, the O / Si ratio is preferably 2.0 or less. When the O / Si ratio is 2.0 or less, the crystallinity of SiO is high, and the inorganic oxide layer can be prevented from becoming too hard, and good tensile resistance is obtained. This makes it possible to suppress the occurrence of cracks in the inorganic oxide layer when the barrier coat layer 32c is laminated. In addition, even after forming into a packaging bag, the first base layer 10 may shrink due to heat during boiling or retort treatment, but when the O / Si ratio is 2.0 or less, the inorganic oxide layer easily follows the above shrinkage, and the deterioration of the barrier property 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 to 1.9, and more preferably 1.8 to 1.85.

[0063] When the 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 can be performed using an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., product name: JPS-90MXV) as a measuring device, a non-monochromated MgKα (1253.6 eV) X-ray source, and an X-ray output of 100 W (10 kV-10 mA). For quantitative analysis to determine 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 deposition layer 32b is, for example, 5 nm or more and 80 nm or less. When the thickness of the deposition layer 32b is 5 nm or more, sufficient water vapor barrier properties can be obtained. When the thickness of the deposition layer 32b is 80 nm or less, the occurrence of cracks due to deformation caused by internal stress of the thin film can be suppressed, and the deterioration of the water vapor barrier properties can be suppressed. Note that, when the thickness of the deposition layer 32b exceeds 80 nm, costs tend to increase due to an increase in the amount of material used and a prolonged film formation time, and this is not preferable from an economical point of view. From the same viewpoint as above, the thickness of the deposition layer 32b may be 20 nm or more and 40 nm or less.

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

[0066] In the vacuum film formation, resistance heating vacuum deposition, EB (Electron Beam) heating vacuum deposition, induction heating vacuum deposition, sputtering, reactive sputtering, dual magnetron sputtering, plasma enhanced chemical vapor deposition (PECVD), etc. are particularly preferably used. However, in terms of productivity, the vacuum deposition is currently the most superior. As a heating means for the vacuum deposition, it is preferable to use any of the electron beam heating method, resistance heating method, and induction heating method.

[0067] (Barrier coat layer 32c) The barrier coat layer 32c is a coating layer having gas barrier properties (gas barrier coating layer) and is provided on the deposition layer 32b. The barrier coat layer 32c is a layer formed using a composition for forming a gas barrier coating layer (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 hydrolysates thereof, for example.

[0068] From the viewpoint of more fully maintaining the gas barrier property after hot water treatment such as retort treatment, the coating agent preferably contains at least a silane coupling agent or a hydrolyzate thereof, 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 a hydrolyzate thereof, and further preferably contains a hydroxyl group-containing polymer compound or a hydrolyzate thereof, a metal alkoxide or a hydrolyzate thereof, and a silane coupling agent or a hydrolyzate thereof. The coating agent can be prepared, for example, by mixing a metal alkoxide and a silane coupling agent directly or after being previously hydrolyzed, into a solution in which a hydroxyl group-containing polymer compound, which is a water-soluble polymer, is dissolved in an aqueous (water or water / alcohol mixture) solvent.

[0069] Each component contained in the coating agent for forming the barrier coat layer 32c will be described in detail. Examples of hydroxyl-containing polymer compounds used in the coating agent include polyvinyl alcohol, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, etc. Among these, polyvinyl alcohol (PVA) is preferably used in the coating agent for the barrier coat layer 32c because it has 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 metal alkoxides represented by the following general formula (I) and hydrolysates thereof. 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 from 1 to n. 1 or R 2 If there are multiple, R 1 Friends or R 2 They may be the same or different.

[0071] Specifically, the metal alkoxide is tetraethoxysilane [Si(OC 2 H 5 ) 4 ], triisopropoxyaluminum [Al(OC 3 H 7 ) 3 Tetraethoxysilane and triisopropoxyaluminum are preferred because they are relatively stable in an aqueous solvent after hydrolysis.

[0072] The silane coupling agent includes a compound represented by the following general formula (II). Si(OR 11 ) p (R 12 ) 3-p R 13 …(II) In the above general formula (II), 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, and R 13 represents a monovalent organic functional group, and p represents an integer of 1 to 3. 11 or R 12 If there are multiple, R 11 R 12 R may be the same or different. 13 Examples of the monovalent organic functional group represented by the formula (I) include a monovalent organic functional group containing a glycidyloxy group, an epoxy group, a mercapto group, a hydroxyl group, an amino group, an alkyl group substituted with a halogen atom, or an isocyanate group.

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

[0074] The silane coupling agent may also be a polymer formed by polymerizing the compound represented by the general formula (II). The polymer is preferably a trimer, more preferably 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate. This is a condensation polymer of 3-isocyanate alkylalkoxysilane. It is known that the isocyanate moiety of this 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate is chemically non-reactive, but the reactivity is ensured by the polarity of the nurate moiety. In general, it is added to adhesives, etc., in the same manner as 3-isocyanate alkylalkoxysilane, 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-isocyanate alkyl alkoxysilanes are highly reactive and have low liquid stability, whereas 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurates are not water-soluble due to the polarity of the nurate moiety, but are easily dispersed in aqueous solutions and can maintain a stable liquid viscosity. In addition, the water resistance of 3-isocyanate alkyl alkoxysilanes is equivalent to that of 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurates.

[0075] 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate may be produced by thermal condensation of 3-isocyanatepropylalkoxysilane, and may contain the raw material 3-isocyanatepropylalkoxysilane, but this does not cause any problem. More preferably, 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate is used, and more preferably, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is used. This methoxy group has a fast hydrolysis rate, and those containing a propyl group are relatively inexpensive and therefore 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is advantageous in practical use.

[0076] Furthermore, known additives such as an isocyanate compound, a dispersant, a stabilizer, a viscosity adjuster, and a colorant can be added to the coating agent as needed, provided that the gas barrier properties are not impaired.

[0077] The thickness of the barrier coat layer 32c is preferably 50 to 1000 nm, and more preferably 100 to 500 nm. If the thickness of the barrier coat layer 32c is 50 nm or more, there is a tendency that more sufficient gas barrier properties can be obtained, and if it is 1000 nm or less, there is a tendency that sufficient flexibility can be maintained.

[0078] The coating liquid for forming the barrier coat layer 32c can be applied by, for example, 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, etc. The coating film obtained by applying this coating liquid can be dried by, for example, 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 for drying the coating film may be, for example, 50 to 150° C., and is preferably 70 to 100° C. By keeping the drying temperature within the above range, the occurrence of cracks in the deposition layer 32b and the barrier coat layer 32c can be further suppressed, and excellent barrier properties can be exhibited.

[0080] The barrier coat layer 32c may be formed using a coating agent containing a polyvinyl alcohol resin and a silane compound. The coating agent may contain an acid catalyst, an alkali catalyst, a photopolymerization initiator, etc., as necessary.

[0081] The polyvinyl alcohol resin is as described above. Examples of the silane compound include a silane coupling agent, polysilazane, and siloxane, and more specifically, examples of the silane compound include tetramethoxysilane, tetraethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, and hexamethyldisilazane.

[0082] [Sealant layer 50] The sealant layer 50 is a layer that imparts heat sealing properties to the laminate 1. From the viewpoint of recycling suitability of the laminate 1, the sealant layer 50 is a polyolefin film similar to the first base layer 10. In this 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 include a polypropylene film or may be made of a polypropylene film.

[0083] 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, etc. As the polypropylene, a polypropylene-based resin such as a homopolypropylene resin (PP), a propylene-ethylene random copolymer, a propylene-ethylene block copolymer, or a propylene-α-olefin copolymer can be used.

[0084] The polypropylene film constituting the sealant layer 50 is preferably a non-oriented polypropylene film from the viewpoint of improving the sealing performance by heat sealing.

[0085] The polypropylene film constituting the sealant layer 50 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent.

[0086] The thickness of the sealant layer 50 is determined depending on the weight of the contents, the shape of the packaging bag, etc., but may be generally 30 to 150 μm, or may be 50 to 80 μm.

[0087] When the sealant layer 50 is heated at 128°C for 15 minutes, it thermally expands in the MD and thermally shrinks in the TD, which makes it easy to obtain the opening height of the packaging bag, although the reason is not clear. From the same viewpoint, when the sealant layer 50 is heated at 128°C for 15 minutes, the heat shrinkage rate in MD calculated 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 TD heat shrinkage calculated by the above formula (2) is preferably 0% or more and 1.0% or less.

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

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

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

[0092] [Print layer] The printing layer can be provided, for example, on at least one surface of the first base 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 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 such as color tone, adhesion, safety as a food container, and the like. Examples of printing methods that can be used include gravure printing, offset printing, gravure offset printing, flexographic printing, and inkjet printing. Among them, gravure printing can be preferably used from the viewpoints of productivity and high definition of the image.

[0093] In order to improve the adhesion of the printed layer, the surface of the layer on which the printed layer is to be formed may be subjected to various pretreatments such as corona treatment, plasma treatment, and frame treatment, or a coating layer such as an easy-adhesion layer may be provided.

[0094] 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 stacking order of the second base layer 31, the anchor coat layer 32a, the deposition layer 32b, and the barrier coat layer 32c may be reversed. 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> A packaging body according to one embodiment will be described below. Fig. 2 is a schematic plan view of an example of the packaging body according to this embodiment. The packaging body 200 includes a packaging bag 100 and contents (not shown) contained in the packaging bag.

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

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

[0098] The maximum opening heights H1 and H2 of the packaging body 200, which are measured through the following process, satisfy the following conditions. When the maximum opening heights H1 and H2 satisfy the following conditions, the opening of the packaging body 200 is difficult to close when the opening is placed vertically downward and the contents are discharged, resulting in excellent dischargeability. 4mm≦H1 6mm≦H2

[0099] (2a) A process in which a first position is 20 mm from the top end of a packaging bag, a second position is the center of the packaging bag in the height direction, the packaging bag is cut from one side to the other side at the first position, the contents are discharged, and then the packaging bag is placed on a horizontal table and the maximum opening height H1 at the first position is measured. (2b) After the step (2a), a step of cutting the packaging bag from one side to the other side at a second position and measuring the maximum opening height H2 at the second position while the packaging bag is placed on a horizontal table.

[0100] The first position is shown in Fig. 2 by the imaginary line II, which is 20 mm away from the top end at a distance L1. The second position is shown in Fig. 2 by the imaginary line II-II, which is the same distance from both the top end and the bottom end at 70 mm. Fig. 3 is an end view at the imaginary line II. The maximum opening height H1 is the maximum distance between the inner edges of the sealant layers as shown in Fig. 3. The same is true for 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 one that has been subjected to a heat treatment at 80° C. or more, 120° C. or more, or 135° C. or less. Examples of the heat treatment include a retort treatment and a boiling treatment.

[0103] Retort processing is a method of sterilizing microorganisms such as mold, yeast, and bacteria by heating and pressurizing them to preserve foods, medicines, etc. In general, a packaging bag containing food, etc. is heated and pressurized at 105 to 140°C, 0.15 to 0.30 MPa, and 10 to 120 minutes. There are two types of retort devices: a steam type that uses heated steam and a hot water type that uses pressurized heated water, and they are used appropriately depending on the sterilization conditions of the contents, such as food. Boiling processing is a method of moist heat sterilization to preserve foods, medicines, etc. Usually, depending on the contents, a packaging bag containing food, etc. is moist heat sterilized at 60 to 100°C, atmospheric pressure, and 10 to 120 minutes. Boiling processing is usually performed using a hot water bath at 100°C or less. There are two types of methods: a batch type in which the bag is immersed in a hot water bath at a constant temperature and treated for a certain period of time, and then removed, and a continuous type in which the bag is passed through a hot water bath in a tunnel-like manner.

[0104] Examples of the contents include food and medicine. The contents may contain water, which is generally difficult to drain, because the packaging bag 100 has excellent drainage properties. The water content may be, for example, 60% by mass or more, preferably 70% by mass or more, and more preferably 75% by mass or more, based on the total amount of the contents. Examples of contents containing water include cooked foods such as soup and pasta sauce, and pet food.

[0105] Although the packaging body according to one embodiment has been described above, the packaging body 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 palm-shaped bag, or a gusset bag. The packaging bag may not have a resealable portion and a notch. The packaging bag may have a knot. The notch may be V-shaped, U-shaped, I-shaped, or the like. Also, a group of scars may be formed instead of the notch. EXAMPLES

[0106] Examples of the present disclosure will be specifically described below, however, the present disclosure is not limited to the following examples.

[0107] <Material preparation> The following materials were prepared as the first base material layer, the second base material layer, the sealant layer, and the adhesive. [First base 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 layer] OPP2A: Biaxially oriented polypropylene film (thickness 20 μm) OPP2B: Biaxially oriented polypropylene film (thickness 20 μm) (Sealant layer) ·CPP-A: Non-oriented polypropylene film (thickness 60μm) ·CPP-B: Non-oriented polypropylene film (thickness 80μm) ·CPP-C: Non-oriented polypropylene film (thickness 60μm) ·CPP-D: Non-oriented polypropylene film (thickness 40μm) ·CPP-E: Non-oriented polypropylene film (thickness 70μm or 80μm) (glue) -Manufactured by Mitsui Chemicals, Inc., Product name: Base 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 in tolylene diisocyanate was equal to the number of OH groups in the acrylic polyol, and diluted with ethyl acetate so that the total solid content (total amount of acrylic polyol and tolylene diisocyanate) was 5 mass%. β-(3,4 epoxycyclohexyl)trimethoxysilane was further added to the diluted mixture so that the amount was 5 mass parts per 100 mass parts of the total amount of acrylic polyol and tolylene diisocyanate, and these were mixed to prepare an anchor coating agent.

[0109] [Preparation of coating solution for barrier coat layer] The following liquids A, B and C were mixed in a mass ratio of 65 / 25 / 10, respectively, to prepare a coating liquid for a barrier coat layer. Liquid A: Tetraethoxysilane (Si(OC 2 H 5 ) 4 72.1 g of 0.1N hydrochloric acid was added to 17.9 g of SiO 2 (equivalent) hydrolysis solution. Liquid B: 5% by mass solution of polyvinyl alcohol in water / methanol (mass ratio of water:methanol is 95:5). Liquid C: A hydrolysis solution in which 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate was diluted with a mixture of water and isopropyl alcohol (water:isopropyl alcohol mass ratio 1:1) to a solid content of 5 mass%.

[0110] <Manufacture of gas barrier film (intermediate layer)> (Examples 1 to 5, Comparative Examples 1, 2, 5, and 6) The material shown in Table 1 was used for the second base layer. The above-mentioned composition for forming an anchor coat layer was applied to the corona-treated surface of the second base layer by gravure roll coating, and then dried and cured at 60°C. The coating amount was 0.1 g / m 2 An anchor coat layer made of a polyester-based polyurethane resin was formed.

[0111] Next, a transparent inorganic oxide layer (silica deposition layer) made of silicon oxide with a thickness of 30 nm was formed by a vacuum deposition apparatus using an electron beam heating method. The deposition material type was adjusted to form a deposition layer with an O / Si ratio of 1.8 for the silica deposition layer. The O / Si ratio was measured with an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., product name: JPS-90MXV) using a non-monochromated MgKα (1253.6 eV) X-ray source at an X-ray output of 100 W (10 kV-10 mA). Quantitative analysis to determine the O / Si ratio was performed using relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p, respectively.

[0112] Next, the above-mentioned coating liquid for the barrier coat layer was applied onto the inorganic oxide layer by gravure roll coating, and then heated and dried in an oven under 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. This resulted in a gas barrier film having a laminated structure of the second substrate layer / anchor coat layer / vapor deposition layer / overcoat layer.

[0113] <Production of Laminate> Laminates of the respective Examples and Comparative Examples were produced based on the combination of each layer shown in Table 1. The method for producing the laminates is as follows.

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

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

[0116] <Loop stiffness value> The laminates of each of the examples and comparative examples were heated at a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa to perform retort treatment. The loop stiffness value of the laminate after heating was measured. For the measurement, a loop stiffness tester manufactured by Toyo Seiki Seisakusho Co., Ltd. was used. A test film having a TD of 15 mm and an MD of 200 mm was prepared from the laminate after heating. A loop having a loop size of 85 mm x 15 mm was formed by fixing both ends of the test film with a chuck. This loop was compressed with an indenter under 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 indenter at that time was measured. The maximum value of the load measured in this test was adopted as the loop stiffness value. The compression distance refers to the distance when the indenter 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 process. The maximum opening height H1 was determined by taking the average of the values ​​measured for three laminates. Similarly, the maximum opening height H2 was determined by taking the average of the values ​​measured for three laminates. The results are shown in Table 2.

[0118] (1a) A process of preparing two laminates with a width of 90 mm and a length of 140 mm as test pieces. (1b) A process in which two test pieces are stacked with the sealant layers facing each other, and three sides are sealed with a seal width of 5 mm to form a bag. (1c) A process in which 70 g of water is poured into the top of the bag, and then the top is sealed with a seal width of 5 mm to obtain a test specimen. (1d) A process of heating the test specimen under conditions of a temperature of 128°C, a time of 15 minutes, and a pressure of 0.3 MPa. (1e) After the step (1d), a step of cutting the bag from one side to the other side at a first position 20 mm from the top end of the bag, draining the water, and then measuring the maximum opening height H1 at the first position while the bag is placed on a horizontal table. (1f) After the (1e) steps, a step of cutting the bag from one side to the other at a second position 50 mm from the first position and measuring the maximum opening height H2 at the second position while the bag is placed on a horizontal table.

[0119] In step (1b), an impulse sealer was used. In step (1c), water was poured into the bag, and the upper end was sealed in this state while the upper part of the bag was folded to remove the air inside the bag. In step (1d), the test specimen was heated while the main surface was placed horizontally. Heating was performed using a shower method in which water was sprayed onto the test specimen. In step (1e), after the water was drained, the inside of the bag was lightly wiped with a Kimwipe to remove moisture. In addition, before measuring the maximum opening height H1, the bag was placed on a horizontal table and the main surface of the bag was pressed with the palm of the hand from the bottom to the top with a force of 2 to 3 kg. In step (1f), before measuring the maximum opening height H2, the bag was placed on a horizontal table and the main surface of the bag was pressed with the palm of the hand from the bottom to the top with a force of 2 to 3 kg.

[0120] <Measurement of shrinkage rate of the first base layer, the second base 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 of each of the Examples and Comparative Examples were measured according to the following procedure. The results are shown in Table 1.

[0121] (1) As shown in FIG. 4, a layer or laminate to be measured was cut into a size of 200 mm×200 mm to prepare a measurement sample 500. (2) As shown in FIG. 4, two straight lines L1 and L2, each having a length of 120 mm or more and parallel to the TD of the measurement sample 500, were drawn with an interval of 100 mm therebetween. (3) As shown in FIG. 4, two straight lines L3 and L4, each having a length of 120 mm or more and parallel to the MD of the measurement sample 500, were drawn with an interval of 100 mm therebetween. (4) As shown in Figure 4, seven graduations N1 to N7 were written at 20 mm intervals on the line L1. Graduations were written similarly on the lines L2 to L4. At this time, the graduations of the lines L1 and L2 were positioned so that when each of the graduations N1 to N7 on the line L1 was connected to each of the graduations N1 to N7 on the line L2, the lines were parallel to MD. In addition, the graduations of the lines L3 and L4 were positioned so that when each of the graduations N1 to N7 on the line L3 was connected to each of the graduations N1 to N7 on the line L4, the lines were parallel to TD. (5) The measurement sample was heated at 128°C for 15 minutes under 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 N1 (intersection of L1 and N1) of the straight line L1 and the scale N1 (intersection of L2 and N1) of the straight line L2 was measured as the MD length before and after heating, and the MD heat shrinkage was calculated by the following formula (1). Similarly, the MD heat shrinkage was calculated at each position of the scales N1 to N7, and the average value of these was determined as the MD heat shrinkage of the measurement sample 500. MD heat 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 (intersection of L3 and N1) and the scale N1 of the straight line L4 (intersection of L4 and N1) was measured as the TD length before and after heating, and the TD heat shrinkage was calculated by the following formula (2). Similarly, the TD heat shrinkage was calculated at each position of the scales N1 to N7, and the average value of these was determined as the TD heat shrinkage of the measurement sample 500. TD heat shrinkage rate (%) = (TD length before heating - TD length after heating) / TD length before heating × 100 ... (2)

[0122] <Emission performance> Two laminates measuring 90 mm wide and 140 mm long 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. Wet pet food (approximately 50 g) was filled into the packaging bag from the top end. The top end of the packaging bag was sealed with an impulse sealer (seal width 5 mm). This resulted in a package comprising a packaging bag and contents (wet pet food).

[0123] The package was heated at a temperature of 128°C for 15 minutes at a pressure of 0.3 MPa. Heating was performed using a shower method in which water was sprayed onto the package. After heating, the package was cut from one side to the other at a first position 20 mm from the top end of the package to form an opening. The maximum opening height of the opening was measured. The package was held for 30 seconds with the opening facing downward in the vertical direction to discharge the contents. After 15 seconds, both sides of the package were pinched with both hands and pushed toward the inside of the package. The amount of contents discharged in 30 seconds was measured. The discharge rate was calculated based on the following formula. Discharge rate (%) = amount of discharged contents (g) / amount of filled contents (g) x 100

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

[0125] <Handling when opening packaging bag> Two laminates measuring 90 mm wide and 140 mm long 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. Wet pet food (approximately 50 g) was filled into the packaging bag from the top end. The top end of the packaging bag was sealed with an impulse sealer (seal width 5 mm). This resulted in a package comprising a packaging bag and contents (wet pet food). The package was heated at a temperature of 128°C for 15 minutes at a pressure of 0.3 MPa. Heating was performed using a shower method in which water was sprayed onto the package. After heating, the package was cut from one side to the other at a first position 20 mm from the top end of the heated package to form an opening. The sealed portions at both ends of the package were grasped, and the amount of force applied when the sealed portions were pressed in a direction to bring them closer together and the ease of maintaining the opening shape were evaluated according to the following criteria A to D to evaluate the handleability when the package was opened. The evaluation was performed according to the following criteria. The results are shown in Table 2. (standard) A: The opening opens with little force and is easy to keep open. B: The opening is easy to open and easy to keep open C: The packaging bag is hard and difficult to open, but the opening is easy to maintain D: The opening is twisted (twisted) making it difficult to open and maintain the opening.

[0126] [Table 1]

[0127] [Table 2] [Explanation of symbols]

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

Claims

1. A base layer; The middle class, A sealant layer; A laminate having a laminate structure comprising, in this order, The maximum opening heights H1 and H2 measured through the following steps satisfy the following conditions: 4mm≦H1 6mm≦H2 The maximum opening heights H1 and H2 are (1a) preparing two test pieces of the laminate having a width of 90 mm and a length of 140 mm; (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 into 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) heating the test specimen at a temperature of 128° C. for 15 minutes under a pressure of 0.3 MPa; (1e) after the step (1d), cutting the bag from one side to the other side at a first position 20 mm from the upper end of the bag, draining the water, and measuring the maximum opening height H1 at the first position while the bag is placed on a horizontal table; (1f) after the step (1e), cutting the bag from one side to the other side at a second position 50 mm from the first position, and measuring a maximum opening height H2 at the second position while the bag is placed on a horizontal table; It is measured through The loop stiffness value after heating at 128° C. for 15 minutes is 80 mN or more and 220 mN or less, A laminate having an MD heat shrinkage percentage calculated by the following formula (1) of 1.0% or more and 3.0% or less, and a TD heat shrinkage percentage calculated by the following formula (2) of 1.0% or more and 3.0% or less, when heated at 128°C for 15 minutes. 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)

2. 10. The laminate of claim 1, wherein the sealant layer thermally expands in the MD and thermally shrinks in the TD when heated at 128°C for 15 minutes.

3. The base material layer is heated at 128° C. for 15 minutes, and the MD heat shrinkage rate calculated by the following formula (1) is S1 ＭＤ The thermal shrinkage rate in the TD calculated by the following formula (2) is S1 ＴＤ When this is done, S1 ＭＤ and S1 ＴＤ Difference from (S1 ＭＤ - S1 ＴＤ 2. The laminate according to claim 1, wherein the ratio of the thickness of the laminate to the thickness of the slab is greater than 0% and less than or equal to 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)

4. The intermediate layer has a second substrate layer, The second base material layer is heated at 128° C. for 15 minutes, and the MD heat shrinkage rate calculated by the following formula (1) is S2 ＭＤ The thermal shrinkage rate of TD calculated by the following formula (2) is S2 ＴＤ When this is done, S2 ＭＤ and S2 ＴＤ Difference with (S2 ＭＤ - S2 ＴＤ 2. The laminate according to claim 1, wherein the ratio of the thickness of the laminate to the thickness of the slab is greater than 0% and less than or equal to 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 laminate according to claim 1 , wherein the maximum opening heights H1 and H2 satisfy the following condition: 4mm≦H1≦7mm 6mm≦H2≦9mm

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

7. A packaging bag formed using the laminate according to any one of claims 1 to 6.

8. The packaging bag according to claim 7, which is used for applications in which a heat treatment at 120°C or more is performed.

9. Packaging bags, Contents contained in the packaging bag; Equipped with The packaging bag is formed using a laminate, The laminate has a laminate structure including a base 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: 4mm≦H1 6mm≦H2 The maximum opening heights H1 and H2 are (2a) a step of setting a position 20 mm from the top end of the packaging bag as a first position, setting the center of the packaging bag in the height direction as a second position, cutting the packaging bag from one side to the other side at the first position, discharging the contents, and then measuring a maximum opening height H1 at the first position while the packaging bag is placed on a horizontal table; (2b) after the step (2a), cutting the packaging bag from one side to the other side at the second position and measuring the maximum opening height H2 at the second position while the packaging bag is placed on a horizontal table; It is measured through 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, When the laminate is heated at 128°C for 15 minutes, the package has an MD heat shrinkage rate calculated by the following formula (1) of 1.0% or more and 3.0% or less, and a TD heat shrinkage rate calculated by the following formula (2) of 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)

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