Content-resistant laminate and method for producing the same

Abstract

To provide a laminate in which an adhesive layer is not corroded even if in contact with content for a long term, and delamination of a sealant layer and a gas barrier layer is not caused, and which can sufficiently prevent adhesion of the content, and to provide a method of producing the same.SOLUTION: Provided is a content resistance laminate with a base material layer, a gas barrier layer, an adhesive layer, and a sealant layer laminated in this order from a surface layer, in which the adhesive layer is melted and co-extruded such that acid-modified polyethylene is arranged on the gas barrier layer side and low-density polyethylene is arranged on the sealant layer side, the gas barrier layer and the sealant layer are sandwich-laminated, the sealant layer is made of a liquid repellent film including a liquid repellent layer, and the acid-modified polyethylene is made of maleic anhydride graft polymerization polyethylene.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate for packaging materials that exhibits excellent resistance to the contents against strong attacks on packaging materials such as hypochlorous acid water, hair coloring agents, fragrances, hypochlorites, herbicides, etc., and a method for producing the same.

Background Art

[0002] As packaging materials used for packaging foods, pharmaceuticals, etc., generally, in order to suppress the deterioration and spoilage of the contents and maintain their functions and properties, a laminate having gas barrier properties that blocks the entry of water vapor, oxygen, and other gases that alter the contents is used.

[0003] Such a laminate is composed of, for example, a base material layer, a gas barrier layer, a sealant layer, etc., and is produced by multilayer laminating a plastic film such as polyethylene, polypropylene, vinyl chloride, polyester, nylon, etc. and a metal foil such as aluminum foil or a metal vapor deposition film via an adhesive layer.

[0004] And as an adhesive for bonding these plastic films and metal foils or metal vapor deposition films, generally, a two-component urethane curable type adhesive for dry lamination is used. However, many of the contents packaged by the packaging material contain alkaline substances, fragrances, surfactants, high-boiling organic solvents, etc. When these contents are packaged, during long-term storage, the components of the contents penetrate into the laminate, particularly attacking the adhesive layer between the gas barrier layer and the sealant layer, resulting in a problem that the sealant layer peels off (delamination) from the gas barrier layer. The packaging material with resistance to the contents is required to have physical properties that prevent such delamination.

[0005] To address such situations, various improvements have been made to the adhesives used in lamination processes. There are those with alcohol resistance (see Patent Document 1), and laminates using maleic anhydride graft-polymerized polyethylene have been proposed as having excellent adhesion to a wide variety of transparent barrier films and aluminum foils and excellent resistance to the contents of the package.

[0006] However, maleic anhydride graft-polymerized polyethylene, which has excellent adhesion to transparent barrier films and aluminum foils, has the problem that heat treatment at a high temperature is required to develop adhesive strength, which causes wrinkles in the laminate. Furthermore, maleic anhydride graft copolymerized polyethylene has a large melt flow rate (hereinafter sometimes referred to as MFR), resulting in a large neck-in during extrusion processing, so there is a problem of poor extrusion processability. The price of the resin is also about four times higher than that of general extrusion resins, which is costly and not preferable.

[0007] In addition, as one aspect of the high functionality of packaging materials, a function to suppress the residue due to the adhesion of the contents to the inner surface of the packaging material is required. Films having high liquid repellency that can suppress the adhesion of the contents to the inner surface, resulting in waste because the contents cannot be used up completely, dirt due to the adhesion of the contents, and the laboriousness of the discharging operation of the contents have been proposed (see Patent Document 2).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention addresses the drawbacks of the above prior art, exhibits excellent resistance to contents, that is, while maintaining sufficient seal strength as a packaging material, active ingredients in the contents do not penetrate, and further, even when in long-term contact with contents containing organic compounds, the adhesive layer is not eroded, thus not causing delamination between the sealant layer and the gas barrier layer, and also can sufficiently suppress the adhesion of the contents. The object is to provide a laminate capable of forming a liquid-repellent layer on the sealant layer and a method for manufacturing the same.

Means for Solving the Problems

[0010] In order to achieve the above object, the invention according to claim 1 is a laminate with excellent resistance to contents, laminated in the order of a base material layer, a gas barrier layer, an adhesive layer, and a sealant layer from the surface layer, wherein the adhesive layer is melt co-extruded such that acid-modified polyethylene is disposed on the gas barrier layer side and low-density polyethylene is disposed on the sealant layer side, and the gas barrier layer and the sealant layer are sandwich laminated, the sealant layer containing a silylated polyolefin is composed of a liquid-repellent film provided with a liquid-repellent layer, and the acid-modified polyethylene is composed of maleic anhydride graft-polymerized polyethylene, and it is a laminate with excellent resistance to contents.

[0011] As described above, as an adhesive layer between the gas barrier layer and the sealant layer affected by the contents, without using an adhesive for dry lamination, by using maleic anhydride graft-polymerized polyethylene as the main component, resistance to contents is provided, and by extrusion with low-density polyethylene having a low MFR, neck-in is reduced and productivity can be improved.

[0012] Further, the invention according to claim 2 is the laminate with excellent resistance to contents according to claim 1, characterized in that the melt co-extruded layer of the maleic anhydride graft-polymerized polyethylene and the low-density polyethylene has a layer thickness ratio of 25:75 to 75:25.

[0013] The invention described in claim 3 is characterized in that the maleic anhydride graft ratio of the maleic anhydride grafted polyethylene is 0.1 Wt% or more and 1.0 Wt% or less, and the density is 0.88 g / cm 3 More than 0.90g / cm 3 MFR is 8.5 or less g / 10 min Over 12.0 g / 10 min 3. The contents-resistant laminate according to claim 1 or 2, characterized in that:

[0014] In the invention described in claim 4, the low density polyethylene has a density of 0.910 g / cm 3 More than 0.930g / cm 3 The following consists of the following, MFR 6.0 g / 10 min Over 8.5 g / 10 min 4. The contents-resistant laminate according to claim 1, wherein the following is satisfied:

[0015] The invention described in claim 5 is as follows: liquid-repellent layer The contents-resistant laminate according to any one of claims 1 to 4, characterized in that it comprises (A) a polyolefin resin, (B) a silylated polyolefin, and (C) a compatibilizer having a portion compatible with the (A) polyolefin resin and a portion compatible with the (B) silylated polyolefin, and the polyolefin portion of the (B) silylated polyolefin is incompatible with the (A) polyolefin resin.

[0016] The invention described in claim 6 is the contents-resistant laminate described in claim 5, wherein the (C) compatibilizer includes at least one selected from the group consisting of a block copolymer of propylene and ethylene, and a block copolymer of ethylene and an ethylene-butylene copolymer.

[0017] The invention described in claim 7 is also characterized in that the content of the silylated polyolefin (B) is 7. The contents-resistant laminate according to claim 5 or 6, wherein the mass ratio of the content of the (C) compatibilizer (mass of the (C) compatibilizer / mass of the (B) silylated polyolefin) is 0.05-20.

[0018] Further, the invention according to claim 8 is the above-mentioned the liquid-repellent layer is , comprising (A) a polyolefin resin and (B) a silylated polyolefin, wherein the polyolefin moiety of the (B) silylated polyolefin is compatible with the (A) polyolefin resin a resin composition , and is the content-resistant physical property laminate according to any one of claims 1 to 4.

[0019] Further, the invention according to claim 9 is the content-resistant physical property laminate according to any one of claims 5 to 8, further comprising (D) silicone on the liquid-repellent film.

[0020] Further, the invention according to claim 10 is the content-resistant physical property laminate according to claim 9, further comprising one or more resin layers provided thereon. liquid-repellent layer

[0021] Further, the invention according to claim 11 is the content-resistant physical property laminate according to claim 10, wherein the melting point T2 (°C) of the resin contained in the (A) polyolefin resin in the liquid-repellent film satisfies the relationship T1 < T2. the melting point T1 (°C) and the resin layer

[0022] The melting point T1 (°C) of the (A) polyolefin resin in the liquid-repellent layer and the melting point T2 (°C) of the resin contained in the resin layer in contact with the liquid-repellent layer among the one or more resin layers may satisfy the relationship T1 < T2. By satisfying the above relationship, from the viewpoint of crystallinity, the migration of the (B) silylated polyolefin in the liquid-repellent layer to the one or more resin layers can be suppressed, and the liquid-repellent property can be further improved.

[0024] Further, Claim 12 the invention described in is the content-resistant physical property laminate having an anticorrosive coating layer made of a zirconium compound between the gas barrier layer and the adhesive layer composed of maleic anhydride graft-polymerized polyethylene and low-density polyethylene in the above laminate. any one of Claims 1 to 11

Advantages of the Invention

[0026] According to the present invention, it is possible to provide a laminate capable of forming a liquid-repellent layer on a sealant layer, which exhibits excellent resistance to the contents, prevents penetration of active ingredients in the contents, etc., and further, even when in long-term contact with the contents containing an organic compound, the adhesive layer is not eroded, thus not causing delamination between the sealant layer and the gas barrier layer, and can sufficiently suppress adhesion of the contents, and a method for manufacturing the same.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0028] An embodiment of the present invention will be described with reference to FIGS. 1 to 4.

[0029] Figs. 1 and 2 are schematic cross-sectional views of the content-resistant laminate according to this embodiment. The content-resistant laminate according to this embodiment is configured by laminating a base material layer 10, a printing layer 11, an adhesive layer 12, a gas barrier layer 13, an adhesive layer 14, and a sealant layer 15 in this order, as in the content-resistant laminate 1 shown in Fig. 1. The sealant layer 15 is made of a liquid-repellent film provided with a liquid-repellent layer 15a. Also, the content-resistant laminate according to this embodiment may be a liquid-repellent film having a structure composed of a liquid-repellent layer 15a and a resin layer 15b, as in the content-resistant laminate 2 shown in Fig. 2, where the base material layer 10, the printing layer 11, the adhesive layer 12, the gas barrier layer 13, the adhesive layer 14, and the sealant layer 15 are laminated in this order. When the sealant layer 15 includes the resin layer 15b, the liquid-repellent layer 15a of the sealant layer 15 is arranged to be in contact with the content.

[0030] <Base material layer> The base material layer 10 is a layer that functions as a support for the laminated film. As the material, a film mainly made of plastic is used, and it is appropriately selected according to the usage conditions such as the type of content when used as a package and the presence or absence of heat treatment after filling. As an example of the material of the base material layer 10, polyethylene, polypropylene, polyethylene terephthalate, nylon, etc. are used, but it is not particularly limited. It may be a single layer made of one of the above materials, or a layer in which a plurality of the above materials are combined by laminating these single layers. In this embodiment, the base material layer 10 is a polyethylene terephthalate film.

[0031] A printing layer 11 is usually formed on the packaging material, but it is preferably formed between the base material layer 10 and the gas barrier layer 13 so that it can be seen from the outside. It is possible to enhance the image of the product and display and print necessary information about the content as needed.

[0032] There are no particular restrictions on the printing method and printing ink, but they can be appropriately selected considering the printability on plastic films, design properties such as color tone, adhesion, and safety as a food container from known printing methods and printing inks. For example, gravure printing method, offset printing method, gravure offset printing method, flexographic printing method, etc. can be used. Among them, the gravure printing method can be preferably used in terms of the print finish and productivity.

[0033] The printing layer 11 and the gas barrier layer 13 can be laminated via the adhesive 12. As the lamination method using the adhesive 12, a known dry lamination method can be used. As the adhesive 12 used for these, a two-component curable urethane adhesive is used.

[0034] <Gas barrier layer> Also, for the purpose of improving the storage stability of the contents, a gas barrier layer 13 can be provided in the packaging material. Thereby, the leakage of the odor of the contents to the outside and the intrusion of oxygen and water vapor gas from the outside can be suppressed, and the deterioration of the contents can be prevented.

[0035] The gas barrier layer 13 is a layer formed by vapor deposition of a metal foil such as aluminum foil or a metal oxide. Examples of the metal oxide include silicon oxide, aluminum oxide, etc., and aluminum oxide is preferable. The method for forming the metal oxide vapor deposition layer is not particularly limited and, for example, vacuum vapor deposition method, sputtering method, etc. can be mentioned. In this embodiment, the gas barrier layer 13 is an aluminum foil.

[0036] <Adhesive layer> The adhesive layer 14 is a layer composed of maleic anhydride grafted polyethylene 14a and low density polyethylene 14b. The maleic anhydride grafted polyethylene 14a is polyethylene obtained by graft-modifying polyethylene with maleic anhydride. The adhesive layer 14 is melt co-extruded such that the maleic anhydride grafted polyethylene 14a is disposed on the gas barrier layer side and the low density polyethylene 14b is disposed on the sealant layer side, and the gas barrier layer 13 and the sealant layer 15 are sandwich laminated. By using no dry laminating adhesive in the adhesive layer 14 and using maleic anhydride grafted polyethylene 14a as the main component, the adhesive layer is not eroded, and thus delamination between the sealant layer 15 and the gas barrier layer 13 can be suppressed. Further, low density polyethylene 14b is added to the adhesive layer 14 because, on the processing surface, if it is a melt extrusion laminate of a single layer of maleic anhydride grafted polyethylene 14a, neck-in is large and productivity is extremely poor because the MFR is high, but by extruding with low density polyethylene 14b having a low MFR, neck-in can be reduced and productivity can be improved. And, the layer thickness ratio of the melt co-extruded layer of maleic anhydride grafted polyethylene 14a and low density polyethylene 14b is preferably between 25:75 and 75:25.

[0037] The maleic anhydride grafting ratio of the maleic anhydride grafted polyethylene 14a is set to 0.1 to 1% by weight. If the maleic anhydride grafting ratio is less than 0.1% by weight, sufficient adhesive strength with the gas barrier film 13 cannot be obtained, and the possibility of delamination occurring becomes high. On the other hand, if the maleic anhydride grafting ratio exceeds 1% by weight, the film strength of the formed adhesive layer decreases, and there arises a problem that sufficient adhesive strength cannot be obtained. The density is 0.88 g / cm 3 or more and 0.90 g / cm 3 or less, and preferably the MFR is 8.5 or more and 12.0 or less. The low density polyethylene 14b consists of a density of 0.910 g / cm 3 or more and 0.930 g / cm 3 or less, and preferably the MFR is 6.0 or more and 8.5 or less.

[0038] In the DSC measurement of maleic anhydride grafted polyethylene 14a, by adding a component that melts at 90°C to 100°C as the main component and a component that continuously exhibits a melting point peak from around 50°C to the low temperature side by 20°C or more, the adhesive strength is developed from a low temperature without wrinkles. Fig. 5 shows the DSC measurement results of maleic anhydride grafted polyethylene.

[0039] <Liquid-repellent film> The sealant layer 15 of the content-resistant laminate 1 according to an embodiment of the present invention is composed of a liquid-repellent film. The liquid-repellent film includes a liquid-repellent layer 15a having liquid-repellent properties. The liquid-repellent film may be a layer capable of exhibiting heat sealability by heating. Here, liquid-repellency is a concept that includes both water-repellency and oil-repellency characteristics. Specifically, it is the property of repelling liquid, semi-solid, or gel-like aqueous or oily materials. Further, heat sealability, for example, refers to the property that heat sealing is possible under the conditions of 100 to 200°C, 0.1 to 0.3 MPa, and 1 to 3 seconds. The heat sealing conditions can be easily changed according to the conditions required for heat sealing the liquid-repellent film. The liquid-repellent layer 15a can be formed using a liquid-repellent layer-forming resin composition containing the following components. Hereinafter, the liquid-repellent layer-forming resin composition will be described.

[0040] <Liquid-repellent layer-forming resin composition> The liquid-repellent layer-forming resin composition according to an embodiment of the present invention contains (A) a polyolefin resin, (B) a silylated polyolefin, and (C) a compatibilizer having a site compatible with the (A) polyolefin resin and a site compatible with the (B) silylated polyolefin, and has a resin composition in which the polyolefin moiety of the (B) silylated polyolefin is incompatible with the (A) polyolefin resin, and may further contain (D) silicone.

[0041] ((A) Polyolefin resin) (A) The polyolefin resin only needs to have heat sealability. For example, linear low-density polyethylene (LLDPE), polyethylene, polypropylene (PP), epoxy resin (EP), ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and their metal crosslinked products, etc. may be mentioned. Among them, considering the retort sterilization suitability in food packaging, etc., PP and heat-resistant LLDPE are preferred. As these thermoplastic resins, one kind may be used alone, or two or more kinds may be used in combination.

[0042] ((B) Silylated polyolefin) The silylated polyolefin is a component that imparts liquid repellency to the liquid repellent film. The silylated polyolefin has a silicone moiety in the polyolefin unit.

[0043] Examples of the silylated polyolefin include products manufactured by Toray Dow Corning Co., Ltd. as a PE-Si graft copolymer, Exfore by Mitsui Chemicals Fine Co., Ltd. as a PE-Si block copolymer, and products manufactured by Toray Dow Corning Co., Ltd. as a PP-Si graft copolymer, etc.

[0044] The silylated polyolefin may be one in which its polyolefin moiety is compatible with the (A) polypropylene resin, or may be incompatible (non-compatible). However, when using a silylated polyolefin in which the polyolefin moiety is incompatible with the (A) polypropylene resin, it is preferably used in combination with the following (C) compatibilizer.

[0045] ((C) Compatibilizer) (C) The compatibilizer is preferably used when a silylated polyolefin in which the polyolefin moiety is incompatible with (A) the polypropylene resin is used as (B) the silylated polyolefin. The compatibilizer is a component having a site compatible with (A) the polypropylene resin and a site compatible with the above (B) silylated polyolefin. By using (C) the compatibilizer, the compatibility between (B) the silylated polyolefin in which the polyolefin moiety is incompatible with (A) the polypropylene resin and (A) the polypropylene resin can be improved.

[0046] As (C) the compatibilizer, for example, a block copolymer of ethylene and propylene, or a block copolymer of ethylene and an ethylene-butylene copolymer can be used.

[0047] ((D) Silicone) Silicone is a component that further improves the liquid repellency of the liquid repellent film. Examples of silicone include silicone oil, silicone resin, silicone oligomer, silicone powder, etc. Among these, silicone oil is preferred because better liquid repellency is easily obtained.

[0048] When the resin composition for forming the liquid repellent layer contains (C) the compatibilizer component, the mass ratio of the content of (C) the compatibilizer component to the content of (B) the silylated polyolefin component ((mass of (C) the compatibilizer component) / (mass of (B) the silylated polyolefin component)) is preferably 0.05 to 20. When the ratio of this content is within the above range, good compatibility is exhibited, and good liquid repellency can be obtained in the liquid repellent layer.

[0049] <Liquid repellent layer 15a and resin layer 15b> The sealant layer 15 of the content-resistant laminate 2 according to an embodiment of the present invention may be a liquid-repellent film having a structure composed of a liquid-repellent layer 15a and a resin layer 15b. The liquid-repellent layer 15a is a layer that can be formed using a liquid-repellent layer-forming resin composition. The resin layer 15b is a layer provided between the liquid-repellent layer 15a and the adhesive layer 14 in order to improve heat sealability, heat resistance, impact resistance, and the like.

[0050] Since the thermoplastic resin used for the resin layer 15b is likely to improve heat sealability, heat resistance, and impact resistance, it preferably contains a polyolefin resin. As the polyolefin resin, the same one as the (A) polypropylene resin used for the liquid-repellent layer 15a can be used.

[0051] When the resin layer 15b is in contact with the liquid-repellent layer 15a, the melting point T1 (°C) of the (A) polypropylene resin in the liquid-repellent layer 15a and the melting point T2 (°C) of the thermoplastic resin in the resin layer 15b preferably satisfy the relationship T1 < T2. By satisfying the above relationship, from the viewpoint of crystallinity, migration of the (B) silylated polyolefin in the liquid-repellent layer 15a to the resin layer 15b can be suppressed, and the liquid repellency tends to be further improved.

[0052] <Anticorrosion coating layer> FIG. 3 and FIG. 4 are schematic cross-sectional views of the content-resistant laminates 3 and 4 according to an embodiment of the present invention, in which an anticorrosion coating layer 16 made of a zirconium compound is provided between the gas barrier layer 13 and the adhesive layer 14. When the gas barrier layer is an aluminum foil, corrosion of aluminum can be prevented by applying the anticorrosion coating.

Examples

[0053] Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

[0054] [Example 1] <Production of liquid-repellent film> (A) component is linear low-density polyethylene (LLDPE, trade name "Evolue", manufactured by Prime Polymer Co., Ltd.), and (B) component is silylated polyethylene (graft copolymer of PE-Si, manufactured by Toray Dow Corning Co., Ltd.). The two components were mixed to prepare a resin composition for forming a liquid-repellent layer. Here, the content of each component was adjusted such that, based on the total amount of (A) component and (B) component, the (B) component was 5% by mass and the balance was the (A) component. Using a three-layer co-extrusion machine, the resin composition for forming a liquid-repellent layer was extruded and formed into a film to obtain a liquid-repellent film composed of a liquid-repellent layer with a thickness of 80 μm.

[0055] <Fabrication of laminate> A 12-μm polyethylene terephthalate substrate (manufactured by Futamura Chemical Co., Ltd.: FE2001) and a 7-μm aluminum substrate (manufactured by Toyo Aluminum Co., Ltd.: 1N30) were dry-laminated using an ester main-chain main agent (manufactured by Mitsui Chemicals, Inc.: A525) and a curing agent (manufactured by Mitsui Chemicals, Inc.: A52) as adhesives. Then, an anticorrosion coating agent containing a zirconium compound (manufactured by Nippon Paint Surf Chemicals Co., Ltd.: Surfcoat EC1000A / B) was applied to the aluminum surface to form an anticorrosion coating layer. And as an adhesive layer, maleic anhydride graft-polymerized polyethylene (M605, manufactured by Mitsubishi Chemical Corporation: melting point peak: 98 °C, density: 0.88 g / cm 3 , MFR 10 g / 10 min) and LC600A (manufactured by Nippon Polyethylene Co., Ltd.: melting point: 106 °C, density: 0.918 g / cm 3, with a melt flow rate (MFR) of 7.0 g / 10 min, was melt co-extruded (layer ratio of M605 to LC600A = 10 μm / 10 μm) and sandwich laminated with the above liquid-repellent film. The T-die width during melt extrusion was 360 mm (air gap: 120 mm). When measuring the resin width after extrusion, it was 253 mm for the extrusion of M605 alone, while it became 303 mm by co-extruding with low-density polyethylene, and the neck-in could be improved by about 20%. On the other hand, in the co-extrusion with resins having an MFR of 13 g / 10 min or more or less than 8.5 g / 10 min, the difference in melt viscosity was large, and the film thickness at the center became thick during film formation, resulting in a significant decrease in smoothness, so it was not suitable. After the extrusion process, heat was applied to the laminated film so that it was held by a heater roll at 140 °C for 15 seconds to produce a laminate.

[0056] [Example 2] As the resin composition for forming the liquid-repellent layer, component (B) was changed to silylated polyethylene (a triblock copolymer of PE-Si-PE, trade name "Exfora", manufactured by Mitsui Chemicals Fine Co., Ltd.), and further silicone oil (dimethyl silicone, manufactured by Toray Dow Corning Co., Ltd.) as component (D) was added. The resin composition for forming the liquid-repellent layer, the liquid-repellent film, and the laminate were produced in the same manner as in Example 1 except that the content of each component was adjusted. The content of each component was adjusted such that, based on the total amount of component (A), component (B), and component (D), component (B) was 5% by mass, component (D) was 5% by mass, and the balance was component (A).

[0057] [Example 3] A laminate was produced in the same manner as in Example 1, except that the resin composition for forming the liquid-repellent layer prepared in the same manner as in Example 1 and linear low-density polyethylene (LLDPE, trade name "Evolue", manufactured by Prime Polymer Co., Ltd.) the same as component (A) were co-extruded into a film using a three-layer co-extrusion machine to obtain a liquid-repellent film composed of a liquid-repellent layer with a thickness of 15 μm and another resin layer with a thickness of 85 μm.

[0058] [Example 4] A laminate was produced in the same manner as in Example 1, except that the thermoplastic resin MZ434 (manufactured by Tamapoly Co., Ltd.; film thickness: 80 μm) was used as the sealant layer.

[0059] [Comparative Example 1] A liquid-repellent layer-forming resin composition, a liquid-repellent film, and a laminate were produced in the same manner as in Example 1, except that an adhesive for dry lamination was used as the adhesive layer between the gas barrier layer and the sealant layer (liquid-repellent film).

[0060] [Evaluation of resistance to contents] The laminate was cut into a size of 100 mm in length × 100 mm in width, folded in half into two pieces to a size of 100 mm in length × 50 mm in width with the sealant layer (liquid-repellent film) on the inside, and one side at the longitudinal end and one side at the transverse end (the side opposite to the folded side) were sealed to produce a three-sided pouch. As the content, a fragrance (strawberry, pH 3.0 to 3.5) was filled, and then the upper part of the pouch was heat-sealed. After storage for 2 weeks, 1 month, 2 months, and 3 months under the conditions of 50°C and humidity-free, the sample was cut into a width of 15 mm, and the adhesive strength between the gas barrier layer (aluminum layer) and the sealant layer (liquid-repellent film) was measured at a tensile speed of 300 m / min using an RTF-1250 manufactured by Koei & Day Co., Ltd. (in accordance with JIS K7127). The results of the adhesive strength are shown in Table 1.

[0061] [Table 1]

[0062] [Liquid-repellent evaluation] A three-sided pouch was produced in the same manner as above. After filling the content, the upper part of the pouch was heat-sealed. A triangular portion with dimensions of 2.5 cm in length × 2.5 cm in width was cut at the corner of the sealed pouch to form a spout. Holding the pouch upside down with the spout and the corner on the diagonal, it was held for 30 seconds to discharge the content, and the discharged amount (g) was weighed. From the weighed discharged amount, the remaining liquid amount (%) was determined by the following formula. Remaining liquid amount (%) = {[(100 - discharged amount) / 100] × 100} ◎: Average remaining liquid amount is less than 2.0% 〇: Average residual liquid volume is 2.0% or more and less than 2.5% △: Average residual liquid volume is 2.5% or more and less than 3.5% ×: Average residual liquid volume is 3.5% or more Also, in the liquid repellency evaluation, the content was dripped onto the film, the film was tilted at 90 degrees, and the appearance evaluation of repellency was visually performed. Repellency (poor) 1: Does not move 2: Linear residue remains 3: Dot-like residue remains 4: Flows without residue (good) The results of the residual liquid volume and the appearance evaluation are shown in Table 2.

[0063]

Table 2

[0064] From the results of Table 1, it was found that by forming by melt coextrusion of maleic anhydride grafted polyethylene and low density polyethylene without using a dry lamination adhesive in the adhesive layer, the adhesive layer is not eroded over time and the adhesive strength is maintained. Therefore, delamination between the sealant layer and the gas barrier layer can be suppressed. Also, by coextruding with a resin having a low MFR, the processability and cost of maleic anhydride grafted polyethylene could be improved.

[0065] On the other hand, from the results of Table 2, by using a liquid repellent film for the sealant layer, the residual rate of the content was low and liquid repellency was also recognized visually.

[0066] From the above, according to the present invention, a laminate capable of forming a liquid repellent layer on a sealant layer that exhibits excellent resistance to contents, does not allow penetration of active ingredients in the contents, and further does not erode the adhesive layer even when in contact with a content containing an organic compound for a long time, and thus does not cause delamination between the sealant layer and the gas barrier layer, and can sufficiently suppress adhesion of the content, and a method for manufacturing the same can be provided.

Explanation of symbols

[0067] 1 to 4... Weather-resistant property laminate 10... Substrate 11... Printing layer 12... Adhesive layer 13... Gas barrier layer 14... Adhesive layer 14a... Maleic anhydride grafted polyethylene 14b... Low density polyethylene 15... Sealant layer (liquid-repellent film) 15a... Liquid-repellent layer 15b... Resin layer 16... Anticorrosion coating layer

Claims

1. A content-resistant laminate in which a base material layer, a gas barrier layer, an adhesive layer, and a sealant layer are laminated in this order from the surface layer, wherein the adhesive layer is melt coextruded such that acid-modified polyethylene is disposed on the gas barrier layer side and low-density polyethylene is disposed on the sealant layer side, and the gas barrier layer and the sealant layer are sandwich laminated, wherein the sealant layer is composed of a liquid-repellent film including a liquid-repellent layer containing silylated polyolefin, wherein the acid-modified polyethylene is composed of maleic anhydride graft polymerized polyethylene, and the content-resistant laminate is characterized by this.

2. The content-resistant laminate according to Claim 1, wherein the melt coextruded layer of maleic anhydride graft polymerized polyethylene and low-density polyethylene has a layer thickness ratio of 25:75 to 75:

25.

3. The maleic anhydride grafting ratio of the maleic anhydride grafted polyethylene is 0.1 Wt% or more and 1.0 Wt% or less, and the density is 0.88 g / cm ３ or more and 0.90 g / cm ３ or less, and the melt flow rate (hereinafter sometimes referred to as MFR) is 8.5 g / 10 min or more and 12.0 g / 10 min or less. The content-resistant physical property laminate according to claim 1 or 2, characterized in that.

4. The low-density polyethylene has a density of 0.910 g / cm ３ or more and 0.930 g / cm ３ or less, and the melt flow rate (MFR) is 6.0 g / 10 min or more and 8.5 g / 10 min or less. The content-resistant physical property laminate according to any one of claims 1 to 3, characterized in that.

5. The liquid-repellent layer contains (A) a polyolefin resin, (B) a silylated polyolefin, and (C) a compatibilizer having a site compatible with the (A) polyolefin resin and a site compatible with the (B) silylated polyolefin, and the polyolefin site of the (B) silylated polyolefin is incompatible with the (A) polyolefin resin. The content-resistant laminate according to any one of Claims 1 to 4, characterized by this resin composition.

6. The content-resistant laminate according to Claim 5, wherein the (C) compatibilizer contains at least one selected from the group consisting of a block copolymer of propylene and ethylene and a block copolymer of ethylene and an ethylene-butylene copolymer.

7. The content-resistant laminate according to Claim 5 or 6, wherein the mass ratio of the content of the (C) compatibilizer to the content of the (B) silylated polyolefin ((mass of (C) compatibilizer / mass of (B) silylated polyolefin)) is 0.05 to 20.

8. The liquid-repellent layer contains (A) a polyolefin resin and (B) a silylated polyolefin, and the polyolefin site of the (B) silylated polyolefin is compatible with the (A) polyolefin resin. The content-resistant laminate according to any one of Claims 1 to 4, characterized by this resin composition.

9. The content-resistant laminate according to any one of Claims 5 to 8, wherein the liquid-repellent layer further contains (D) silicone.

10. The anti-content property laminate according to claim 9, further comprising one or more resin layers provided on the liquid-repellent layer.

11. The anti-content property laminate according to claim 10, wherein the melting point T1 (°C) of the (A) polyolefin resin in the liquid-repellent layer and the melting point T2 (°C) of the resin contained in the resin layer satisfy the relationship of T1 < T2.

12. The anti-content property laminate according to any one of claims 1 to 11, wherein in the laminate, an anticorrosion coating layer made of a zirconium compound is provided between the gas barrier layer and the adhesive layer composed of the maleic anhydride graft polymerized polyethylene and the low density polyethylene.

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