Laminate material for molded container

Abstract

To provide a laminate material for a molded container allowed to form a comparatively-large molded container with bulge processability in molding the molded container improved by performing bulge processing on a laminate material and positively prevent the occurrence of delamination in the laminate material forming the molded container due to the heat applied during retort treatment of a package having the molded container.SOLUTION: A laminate material 1 for an in-line molded container comprises a base material layer 2 consisting of a biaxial oriented nylon film, a barrier layer 3 consisting of a metal foil and a heat-seal layer 4, which layers are laminated in order. The base material layer 2, when heated under a constant heating condition, has a difference in absolute value between a percentage of shrinkage (%) in a flow direction (MD) and a percentage of shrinkage (%) in a width direction (TD) of equal to or smaller than 0.5. Adhesion-facilitation treatment is done over a surface of the base material layer 2 adjoining the barrier layer 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate for forming containers, which is used to produce formed containers used in packaging that contains contents such as food and is subjected to retort treatment.

[0002] In this specification, the term "inline-molded container" refers to a container that is formed in a series of steps in a so-called inline method of manufacturing a package, in which a container is formed by applying a bulging process to a container laminate, the container is filled with contents, and then a lid material is heat-sealed around the opening edge of the container to produce a package.

[0003] In this specification, the term "aluminum" includes aluminum alloys as well as pure aluminum. [Background technology]

[0004] A widely known package for packaging contents that need to be protected from gases, water vapor, light, etc., such as food, pharmaceuticals, and fine chemicals, is one that consists of a molded container formed using a laminated material with a barrier layer and containing the contents, and a lid material formed using a laminated material with a barrier layer and heat-sealed to the periphery of the opening of the molded container to close the opening of the molded container.

[0005] One known method for producing the above-mentioned package is a so-called in-line method, in which a laminate having a barrier layer is cold-drawn to form a plurality of in-line-molded containers in succession, the contents are sequentially filled into each in-line-molded container, the contents are sequentially heat-sealed to the peripheral opening edges of the in-line-molded containers to form a multiple package, and the multiple package is divided, all of which are carried out continuously on a single line. Another known method for producing the above-mentioned package is a method in which a laminate having a barrier layer is cold-drawn or bulged to form a molded container, the contents are filled into the molded container, and the contents are heat-sealed to the peripheral opening edges of the molded container to form a package, all of which are carried out on separate lines.

[0006] Patent Document 1 discloses a laminated material that is used to manufacture molded containers when producing packaging bodies by the two manufacturing methods described above, and that includes a biaxially oriented film made of a resin such as polyethylene terephthalate, nylon, or polypropylene, aluminum foil, an adhesive layer, and a film made of polypropylene laminated in that order. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 6-345123 Summary of the Invention [Problem to be solved by the invention]

[0008] However, as described in paragraph

[0027] of Patent Document 1 as "diameter 29 mm x 33 mm, depth 6 mm," the molded container manufactured from the laminated material disclosed in Patent Document 1 is quite small.

[0009] Recently, there has been a demand for larger molded containers used in packages manufactured by the above-mentioned manufacturing method. In particular, it is considered that packages manufactured by the inline method will contain contents such as food that require retort treatment, and there is a demand for larger inline molded containers. In order to achieve larger inline molded containers, it is necessary to improve the bulging processability when bulging the laminated material. Furthermore, it is necessary to prevent delamination from occurring in the laminated material that forms the molded container due to the heat applied during the retort treatment of the package.

[0010] In view of the above-mentioned circumstances, the present invention aims to provide a laminated material for molded containers that improves the bulging processability when applying bulging processing to the laminated material to form a molded container, making it possible to form relatively large molded containers, and that can reliably prevent delamination from occurring in the laminated material that forms the molded container due to the heat applied during retort processing of a packaging body containing the molded container. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention comprises the following aspects.

[0012] 1) A laminated material for producing a molded container used in a package to be subjected to retort treatment, in which a base layer, a barrier layer, and a heat seal layer are laminated in this order, A laminate for molding containers, wherein the base layer is made of a biaxially oriented nylon film in which, when heated under certain heating conditions, the absolute value of the difference between the shrinkage rate (%) in the machine direction (MD) and the shrinkage rate (%) in the transverse direction (TD) is 0.5 or less, and the surface of the base layer that comes into contact with the barrier layer is treated to facilitate adhesion. Here, the shrinkage rate (%) when heated is calculated using the following formula. Shrinkage rate (%) = {(sample length before heating - sample length after heating) / sample length before heating} x 100 2) The laminate for molded containers according to 1) above, wherein the base layer is made of a biaxially oriented nylon film having a thickness of 9 to 40 μm, and when heated under certain heating conditions, the shrinkage percentage (%) in the machine direction (MD) and the shrinkage percentage (%) in the transverse direction (TD) are both 1.5% or less, the barrier layer is made of a metal foil having a thickness of 60 to 140 μm, and the heat seal layer is made of an unstretched polypropylene film having a thickness of 40 to 200 μm.

[0013] 3) The laminate for molding containers according to 1) above, wherein an adhesive layer is provided between the base layer and the barrier layer, and the adhesive layer is made of a two-component curing urethane adhesive.

[0014] 4) The laminate for forming containers according to 1) above, wherein the wet laminate strength between the base layer and the barrier layer after retort treatment is 2.0 N / 15 mm or more.

[0015] 5) The molding container to be produced is an in-line molding container, and the depth of the in-line molding container is 10 to 20 mm, and the capacity is 50 to 400 cm 3 The laminate for forming containers according to the above 1), wherein:

[0016] 6) A package comprising a molded container comprising a container body having a bottom wall and a peripheral wall integrally formed rising from the periphery of the bottom wall and having an opening surrounded by the upper end of the peripheral wall, and an outward flange integrally formed at the upper end of the peripheral wall, contents placed in the container body, and a lid material heat-sealed to the flange of the molded container to close the opening of the container body, A package, wherein the formed container is formed by processing the laminate for formed containers according to any one of 1) to 5) above. [Effects of the Invention]

[0017] According to the laminate for molded containers described above in 1) to 5), the base layer is made of a biaxially oriented nylon film in which the absolute value of the difference between the shrinkage percentage (%) in the machine direction (MD) and the shrinkage percentage (%) in the transverse direction (TD) when heated under certain heating conditions is 0.5 or less. Therefore, when the laminate is bulged or drawn to form a molded container, a uniform force is applied to the metal foil forming the barrier layer, improving processability and enabling the molding of relatively large molded containers. In particular, during the inline manufacturing process of packaging, the bulging process applied to the laminate improves bulging processability when forming inline molded containers, enabling the molding of relatively large molded containers. Furthermore, it is possible to prevent delamination of the laminate for molded containers due to heat applied during retort processing of packages containing food or the like, or heat applied during heat sealing of lids after filling the containers with contents.

[0018] Furthermore, according to the laminate for molded containers described above in 1) to 5), the surface of the base material layer that comes into contact with the barrier layer is subjected to an easy-adhesion treatment, so that it is possible to effectively prevent delamination from occurring between the base material layer and the barrier layer of the laminate for molded containers due to heat applied during retort processing of the food packaged in the package or heat applied during heat sealing of the lid material after the contents have been filled into the molded container.

[0019] According to the laminate for formed containers described in 2) above, when the laminate is subjected to bulging or drawing to form a formed container, force is applied evenly to the metal foil forming the barrier layer, improving processability and making it possible to form relatively large formed containers. In particular, in the process of manufacturing packaging using the inline method described above, bulging the laminate improves bulging processability when forming inline formed containers, making it possible to form relatively large inline formed containers. Furthermore, it becomes possible to prevent delamination of the laminate for formed containers caused by heat applied during retort treatment of a package containing food or the like, or heat applied during heat sealing of a lid after filling the contents into the formed container.

[0020] The laminated materials for molded containers described in 3) and 4) above can reliably prevent delamination from occurring in the laminated materials for molded containers due to heat applied during the retort treatment of a package containing food or the like, or heat applied during heat sealing of the lid material after the contents have been filled into the molded container.

[0021] As described in 5) above, the molding container to be produced is an in-line molding container, and the depth of the in-line molding container is 10 to 20 mm, and the capacity is 50 to 400 cm 3 Even if the laminate for formed containers is relatively large as described above, the laminate for formed containers described in 1) to 4) above makes it possible to use the laminate for inline bulging forming of formed containers by bulging processing in inline manufacturing of packaging bodies. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is an enlarged cross-sectional view showing a laminate for forming containers according to the present invention. [Figure 2] 2 is a plan view showing a specific example of an in-line molded container molded using the laminate for molded containers of FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line XX in FIG. 2. [Figure 4] 1A and 1B show formed containers formed by bulging processing using laminated materials according to examples of the present invention and comparative examples, where (a) is a plan view and (b) is a cross-sectional view taken along line YY in (a). DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a laminate for formed containers according to the present invention is applied to the forming of in-line formed containers. However, the technical scope of the present invention is not limited to the embodiment shown in the drawings.

[0024] FIG. 1 shows a laminate for formed containers according to the present invention, and FIGS. 2 and 3 show in-line formed containers formed using the laminate of FIG. 1 in the process of manufacturing packaging products by an in-line method.

[0025] In Fig. 1, the laminate material for molded containers (1) is a composite material in which a base layer (2) made of a thermoplastic resin film, a barrier layer (3) made of a metal foil, and a heat-seal layer (4) are laminated in this order from one side. Adhesive layers (5) and (6) are interposed between the base layer (2) and the barrier layer (3) and between the barrier layer (3) and the heat-seal layer (4), respectively.

[0026] 2 and 3 show an in-line molded container formed using the laminated material (1) of FIG.

[0027] 2 and 3, the in-line molded container (10) comprises a container body (11) having a bottom wall (12) and a peripheral wall (13) formed integrally and rising from the periphery of the bottom wall (12) and having an opening (14) surrounded by the upper end of the peripheral wall (13), and an outward flange (15) formed integrally at the upper end of the peripheral wall (13). The bottom wall (12) and opening (14) of the container body (11) are approximately rectangular in shape when viewed from above, with rounded corners (16) and (17). A rounded corner (18) is also formed at the junction between the bottom wall (12) and peripheral wall (13) of the container body (11). The outer peripheral edge of the outward flange (15) is rectangular in shape when viewed from above. In this embodiment, in the process of manufacturing a package by the inline method, four inline-formed containers (10) are arranged two by two vertically and horizontally and connected together by flanges (15) to form a multiple-connected structure. The connecting portions between the flanges (15) of the inline-formed containers (10) are indicated by (C). For example, when the contents are foodstuffs, the depth of the container body (11) of each inline-formed container (10) is 10 to 20 mm, and the capacity is 50 to 400 cm. 3 It is preferable that:

[0028] The base material layer (2) of the laminate material (1) for inline molded containers forms the outermost surfaces of the bottom wall portion (12) and peripheral wall portion (13) of the container body (11) of each inline molded container (10) and the lowermost surface of the flange portion (15), and the heat seal layer (4) forms the innermost surfaces of the bottom wall portion (12) and peripheral wall portion (13) of the container body (11) of each inline molded container (10) and the uppermost surface of the flange portion (15).

[0029] The layers (2) to (6) of the laminated material for forming containers (1) will be described in detail below. [Base material layer (2)] The base material layer (2) improves bulging processability when the laminate for formed containers (1) is bulged to form an in-line formed container (10), and also suppresses delamination between the base material layer (2) and the barrier layer (3) due to heat applied when heat-sealing a lid material to the in-line formed container (10) or heat applied during retort processing of a package having the in-line formed container (10) and in which food or the like is packaged, and the thickness of the base material layer (2) is preferably 9 to 40 μm. If the thickness of the base material layer (2) is less than 9 μm, the barrier layer (3) may break during forming, while if it exceeds 40 μm, the residual stress during forming the container may become too high, causing delamination between the base material layer (2) and the barrier layer (3).

[0030] The base layer (2) is limited to a biaxially oriented nylon film in which the absolute value of the difference between the shrinkage percentage (%) in the machine direction (MD) and the shrinkage percentage (%) in the transverse direction (TD) is 0.5 or less when heated under certain heating conditions, for example, at 160°C for 10 minutes. Here, the shrinkage percentage (%) upon heating is calculated using the following formula: Shrinkage rate (%) = {(sample length before heating - sample length after heating) / sample length before heating} x 100

[0031] The base layer (2) is preferably formed from a biaxially oriented nylon film that exhibits shrinkage (%) of 1.5% or less in both the machine direction (MD) and the transverse direction (TD) when heated under certain heating conditions, for example, at 160°C for 10 minutes.

[0032] Furthermore, the surface of the substrate layer (2) on the barrier layer (3) side should be subjected to an easy-adhesion treatment using an adhesive composition for forming an easy-adhesion layer, which contains a base material such as a polyamide resin, a polyester resin, a water-based polyurethane resin, or an acrylic resin, a crosslinking agent such as a water-soluble epoxy resin or a water-soluble oxazoline, and a coating agent (average particle size 0.001 to 1.0 μm) whose main components are fine particles such as colloidal silica.

[0033] [Barrier layer (3)] The barrier layer (3) is a layer that protects the contents of a package having an in-line forming container (10) formed from the laminate for forming containers (1) from gas, water vapor, light, etc. and is made of metal foil formed from metals such as aluminum, copper, iron (stainless steel), titanium, and nickel. However, aluminum foil is preferred in consideration of processability, barrier function, cost, etc., for ensuring the required depth of the in-line forming container (10). As the aluminum foil, a foil made of a soft aluminum material (O material) of 1000 series or 8000 series as specified in JIS H4160:1994 and having a thickness of 60 to 140 μm is preferred. If the thickness of the aluminum foil forming the barrier layer (3) is less than 60 μm, the strength and rigidity of the in-line forming container (10) may be insufficient, and if it exceeds 140 μm, formability may be impaired.

[0034] The aluminum foil forming the barrier layer (3) is preferably an aluminum foil made of an Al-Fe alloy containing 0.7 to 1.7% by mass of Fe, specifically, an A8021H-O material or an A8079H-O material as specified in JIS H4160:1994. The content of Si as an impurity in an Al-Fe alloy containing 0.7 to 1.7% by mass of Fe is preferably 0.1% by mass or less. When an aluminum foil made of an Al-Fe alloy containing 0.7 to 1.7% by mass of Fe is used as the barrier layer (3), the processability during bulging of the in-line forming container (10) is improved, the occurrence of wrinkles in the bottom wall portion (12) and the peripheral wall portion (13) of the container body (11) is suppressed, and sufficient flatness of the flange portion (15) is ensured. Furthermore, as shown in FIG. 2, even when a plurality of inline-molded containers (10) are connected in a row, the occurrence of wrinkles in the bottom wall portion (12) and the peripheral wall portion (13) of the container body (11) is suppressed, and sufficient flatness of the flange portion (15) is ensured.

[0035] It is preferable that at least the surface of the barrier layer (3) facing the base layer (2) be subjected to a surface treatment such as a chemical conversion treatment. By subjecting at least the surface of the barrier layer (3) facing the base layer (2), the adhesion between the barrier layer (3) and the adhesive layer (5) after the bulging process can be strengthened, ensuring sufficient formability and sufficiently preventing delamination between the base layer (2) and the barrier layer (3) when the resulting in-line formed container (10) is filled with contents and the lid is heat-sealed and the resulting package is subjected to a heat sterilization process. The surface of the barrier layer (3) facing the heat-seal layer (4) may also be subjected to a chemical conversion treatment. In this case, the adhesion between the barrier layer (3) and the adhesive layer (6) after the bulging process can be strengthened, achieving the same effect as described above.

[0036] The above-mentioned chemical conversion treatment is carried out by, for example, applying the following to the surface of the barrier layer (3) made of a metal foil that has been subjected to a degreasing treatment: 1) an aqueous solution consisting of a mixture of metal salts of phosphoric acid, chromic acid and fluoride; 2) an aqueous solution consisting of a mixture of metal and non-metal salts of phosphoric acid, chromic acid, and fluoride; and 3) An aqueous solution consisting of a mixture of acrylic resin and / or phenolic resin, phosphoric acid, chromic acid, and a metal fluoride salt. The coating is carried out by applying any one of the above and then drying.

[0037] [Heat seal layer (4)] The heat seal layer (4) is made of a polyolefin resin, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), homopolypropylene (hPP), ethylene-propylene random copolymer (rPP), or ethylene-propylene block copolymer (bPP). These resins may be used alone or in combination. These resins may be used in single-layer or multi-layer configurations. Among these, a three-layer unstretched polypropylene film consisting of a bPP film sandwiched between rPP films is preferred.

[0038] The thickness of the heat seal layer (4) is preferably 40 to 200 μm. If the thickness of the heat seal layer (4) is less than 40 μm, the internal pressure strength may be insufficient, while if it is more than 200 μm, the cost will be high and the aluminum ratio will be low, which may reduce recyclability after use. The internal pressure strength is measured by inserting a needle into a package filled with contents or water and sealed, fixing it so that there is no air leakage, connecting a pressure gauge and compressor to the needle, operating the compressor, and sending air at a flow rate of 1±0.2 L per minute, and reading the maximum pressure when the package bursts.

[0039] [Adhesive layer (5)(6)] The adhesive layer (5) between the substrate layer (2) and the barrier layer (3) is formed of, for example, an ester-based two-component curing urethane adhesive, an acid-modified polypropylene adhesive, or the like.

[0040] The adhesive layer (6) between the barrier layer (3) and the heat seal layer (4) is formed of, for example, an ester-based two-component curing urethane adhesive, an acid-modified polypropylene adhesive, or the like.

[0041] The above-described embodiment is an application of the laminated material for molded containers according to the present invention to the molding of inline molded containers by bulging processing in an inline method of manufacturing packaging bodies, but the present invention is not limited to this and can also be applied to the molding of molded containers by ordinary individual bulging processing or drawing processing.

[0042] Next, examples of the present invention and comparative examples will be described. [Example 1] As the thermoplastic resin film forming the base layer (2), a biaxially oriented nylon film having a thickness of 25 μm and a shrinkage rate (%) of 0.8% in the machine direction (MD) and 1.3% in the transverse direction (TD) when heated at 160°C for 10 minutes, with the absolute value of the difference between the two being 0.5, was prepared. As the metal foil forming the barrier layer (3), an 80 μm thick aluminum foil made of A8021H-O material specified in JIS H4160:1994 was prepared. As the heat-sealable resin forming the heat-seal layer (4), an 80 μm thick unstretched polypropylene film was prepared.

[0043] A chemical conversion treatment solution (pH = 1) consisting of polyacrylic acid, a trivalent chromium compound, phosphoric acid, pure water, and isopropyl alcohol was prepared. Furthermore, 70 parts by weight of Mitsui Chemicals' "Takelac W-6010" water-based urethane resin, 30 parts by weight of Nagase Chemtec's "Denacol EX-521" water-based epoxy resin, and 5 parts by weight of Nissan Chemical Industries' "Snowtex ST-C" colloidal silica (average particle size 10-20 nm) as an antiblocking agent were mixed and diluted with ion-exchanged water to prepare an adhesive composition for forming an easy-adhesion layer with a nonvolatile content of 2% by weight.

[0044] The adhesive for forming the easy-adhesion layer was applied to the surface of the biaxially oriented nylon film forming the base layer (2) to be adhered to the barrier layer (3) using a gravure coater to a thickness of 0.2 μm, and then dried to form an easy-adhesion layer. The chemical conversion treatment solution was applied to both sides of the aluminum foil forming the barrier layer (3), and then dried at 180° C. to form a chromium coating amount of 10 mg / m 2 The film was subjected to a chemical conversion treatment so that the film was as follows:

[0045] Next, 3.5 g / m of an ester-based two-component curing urethane adhesive was applied to one side of the aluminum foil that would become the barrier layer (3). 2 The adhesive is used to bond a biaxially oriented nylon film that will become the base layer (2), and an ester-based two-component curing urethane adhesive is applied at 3.5 g / m to the other side of the aluminum foil that will become the barrier layer (3). 2 The adhesive was used to bond an unstretched polypropylene film that would become the heat seal layer (4), thus producing a laminate material (1) for molded containers.

[0046] [Comparative Example 1] A laminate material (1) for a molded container was produced in the same manner as in Example 1 above, except that a biaxially oriented nylon film having a thickness of 25 μm and a shrinkage rate (%) of 1.9% in the machine direction (MD) and 0.5% in the transverse direction (TD) when heated at 160°C for 10 minutes was used as the thermoplastic resin film forming the base layer (2). The absolute value of the difference between the shrinkage rates was 1.4.

[0047] Comparative Example 2 A laminated material (1) for a molded container was produced in the same manner as in Example 1 above, except that a biaxially oriented nylon film having a thickness of 25 μm and a shrinkage rate (%) of 1.9% in the machine direction (MD) and 0.5% in the transverse direction (TD) when heated at 160°C for 10 minutes, with the absolute value of the difference between the shrinkage rates being 1.4, was used as the thermoplastic resin film forming the base layer (2), and that no easy-adhesion treatment was applied to the adhesive surface of the biaxially oriented nylon film forming the base layer (2) to the barrier layer (3).

[0048] Comparative Example 3 A laminated material (1) for a molded container was produced in the same manner as in Example 1 above, except that a biaxially oriented nylon film having a thickness of 25 μm, which had a shrinkage rate (%) of 0.9% in the machine direction (MD) and a shrinkage rate (%) of 1.0% in the transverse direction (TD) when heated at 160°C for 10 minutes, with the absolute value of the difference between the two being 0.1, was used as the thermoplastic resin film forming the base layer (2), and that no easy-adhesion treatment was applied to the adhesive surface of the biaxially oriented nylon film forming the base layer (2) to the barrier layer (3).

[0049] [Evaluation test] Dry Laminate Strength The laminated materials (1) for molding containers of Example 1 and Comparative Examples 1-3 were cut into strips with a width of 15 mm, and a T-peel test was carried out in a dry atmosphere according to the method specified in JIS-K-6854-3 (T-peel) 6.4b, and the dry laminate strength between the base layer (2) and the barrier layer (3) was measured at a peel rate of 100 mm / min.

[0050] Wet Laminate Strength The laminated materials (1) for molded containers of Example 1 and Comparative Examples 1-3 were cut into strips with a width of 15 mm and subjected to retort treatment. Thereafter, a T-peel test was carried out in a humid atmosphere according to the method specified in JIS-K-6854-3 (T-peel) 6.4b, and the wet laminate strength between the base layer (2) and the barrier layer (3) was measured at a peel rate of 100 mm / min.

[0051] Stretchability The container laminates (1) of Example 1 and Comparative Examples 1-3 were subjected to bulging processing to form containers (100) as shown in Fig. 4. The container (100) comprises a bottom wall (120) and a peripheral wall (130) formed integrally and rising from the periphery of the bottom wall (120), a container body (110) having an opening (140) surrounded by the upper end of the peripheral wall (130), and an outward flange (150) provided at the upper end of the peripheral wall (130) and having an outer peripheral edge with a rectangular shape when viewed from above. The bottom wall (120) of the container body (110) has a rectangular shape measuring 110 mm x 60 mm in plan view, with the corners rounded (160) with a radius of curvature of 15 mm, the opening (140) has a rectangular shape measuring 130 mm x 80 mm in plan view, with the corners rounded (170) with a radius of curvature of 25 mm, and the flange (150) has a rectangular shape measuring 150 mm x 100 mm in plan view. The longitudinal directions of the bottom wall (120), opening (140), and flange (150) are all oriented in the same direction. The depth of the container body (110) is 18 mm, and a curve (180) with a radius of curvature of 10 mm is formed between the bottom wall (120) and the peripheral wall (130) of the container body (110), and a curve (190) with a radius of curvature of 1 mm is formed between the peripheral wall (130) and the flange (150) of the container body (110). Furthermore, the internal volume of the container is 150 cm 3 is.

[0052] Then, whether or not breakage occurred in the laminated material (1) during the bulging process of the container was observed, and the bulging processability was evaluated.

[0053] Heat resistance during heat sealing The molded container was placed in an oven and heated and pressurized at 200°C and a pressure of 0.1 MPa for 30 seconds, which were the same heating conditions as those used when heat-sealing the lid material to the flange portion (150) of the container, and the occurrence of delamination between the base layer (2) and the barrier layer (3) was examined.

[0054] Heat resistance during retort processing The molded container was subjected to a retort treatment at 120°C for 3 minutes, and the occurrence of delamination between the base layer (2) and the barrier layer (3) was examined.

[0055] The results of the above evaluation tests are summarized in Table 1.

[0056] [Table 1]

[0057] In Table 1, a circle in the column for bulging workability indicates that no fracture occurred in the laminate (1) during bulging. The occurrence of fracture was determined visually. In the column for heat resistance during heat sealing, a circle indicates that no delamination occurred between the base layer (2) and the barrier layer (3) after heating, and a triangle indicates that delamination occurred in the portion indicated by A in Figure 4. In the column for heat resistance during retort treatment, a circle indicates that no delamination occurred between the base layer (2) and the barrier layer (3) after heating, a triangle indicates that delamination occurred in the portion indicated by A in Figure 4, and an × indicates that delamination occurred in the portion indicated by A in Figure 4 and in the flange portion, which is the non-molded portion.

[0058] As is clear from Table 1, the laminate for forming containers of Example 1 and Comparative Examples 1-3 have comparable bulging processability. However, the laminate for forming containers (1) of Example 1, in which the absolute value of the difference between the shrinkage rate (%) in the machine direction (MD) and the shrinkage rate (%) in the transverse direction (TD) when heated at 160°C for 10 minutes is 0.5 or less and the surface of the base layer that comes into contact with the barrier layer is subjected to an easy-adhesion treatment, is superior to Comparative Examples 1-3 in both laminate strength in a dry atmosphere and in a humid atmosphere after heat treatment, and heat resistance when subjected to heat treatment corresponding to the heat-sealing conditions and when subjected to retort treatment. [Industrial Applicability]

[0059] The laminate for formed containers according to the present invention is preferably used for producing relatively large formed containers that are manufactured by bulging or drawing and that constitute packages for accommodating contents that are to be subjected to retort treatment. [Explanation of symbols]

[0060] (1): Laminated material for forming containers, (2): Base material layer, (3): Barrier layer, (4): Heat seal layer, (10): In-line forming container

Claims

1. A laminated material for producing a molded container used in a packaging body that is subjected to retort treatment, comprising a base material layer, a barrier layer, and a heat seal layer laminated in that order, a laminate for a molding container, the base layer comprising a biaxially oriented nylon film in which, when heated under certain heating conditions, the absolute value of the difference between the shrinkage rate (%) in the machine direction (MD) and the shrinkage rate (%) in the width direction (TD) is 0.5 or less, and the surface of the base layer that comes into contact with the barrier layer is subjected to an easy-adhesion treatment.

2. 2. The laminate for molded containers according to claim 1, wherein the base layer is made of a biaxially oriented nylon film having a thickness of 9 to 40 μm, and when heated under certain heating conditions, the shrinkage percentages (%) in both the machine direction (MD) and the transverse direction (TD) are 1.5% or less, the barrier layer is made of a metal foil having a thickness of 60 to 140 μm, and the heat seal layer is made of an unstretched polypropylene film having a thickness of 40 to 200 μm.

3. 2. The laminate for forming containers according to claim 1, further comprising an adhesive layer provided between said base layer and said barrier layer, said adhesive layer being made of a two-component curing urethane adhesive.

4. 2. The laminate for forming containers according to claim 1, wherein the wet laminate strength between the base layer and the barrier layer after retort treatment is 2.0 N / 15 mm or more.

5. The molding container to be produced is an in-line molding container, and the depth of the in-line molding container is 10 to 20 mm and the capacity is 50 to 400 cm ３ 2. The laminate for forming containers according to claim 1, wherein

6. A package comprising a molded container comprising a container body having a bottom wall and a peripheral wall integrally formed rising from the periphery of the bottom wall and having an opening surrounded by the upper end of the peripheral wall, and an outward flange integrally formed at the upper end of the peripheral wall, contents placed in the container body, and a lid material heat-sealed to the flange of the molded container to close the opening of the container body, A packaging body, wherein the formed container is formed by processing the laminate for formed containers according to any one of claims 1 to 5.

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