Substrates for vapor deposition film formation, vapor deposition substrates, laminates, and packaging containers

Abstract

To provide a substrate for forming a vapor-deposited film favorably usable for producing a mono-material packaging container, with high adhesion to a vapor-deposited film, and capable of effectively preventing delamination when made into a packaging container.SOLUTION: A substrate for forming a vapor-deposited film at least includes a first polyethylene resin layer with a vapor-deposited film formed on a surface thereof. A density of a polyethylene resin composing the first polyethylene resin layer is 0.943 g / cm3 or less. A drawing process is applied to the substrate for forming a vapor-deposited film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate for forming a vapor-deposited film, a vapor-deposited substrate, a laminate, and a packaging container.

[0002] Conventionally, resin films made from polyester resins such as polyethylene terephthalate (hereinafter also referred to as polyester films) have been used as a base material for laminates used in the manufacture of packaging containers because they have excellent mechanical properties, chemical stability, heat resistance, and transparency, as well as being inexpensive.

[0003] Such polyester films are typically laminated with a polyethylene film, which acts as a sealant layer, to form a laminate, which is then molded into a packaging container.

[0004] As described above, packaging containers made from laminates of different types of resin films, namely polyester film and polyethylene film, are difficult to separate into their respective layers. Therefore, packaging containers collected after use are not suitable for recycling and are not actively recycled.

[0005] Furthermore, with the aim of improving the recyclability of packaging containers, the use of stretched polyethylene film (stretched polyethylene film) as the base material instead of polyester film, and the production of packaging containers (monomaterial packaging containers) using laminates made of the same material are being considered. [Overview of the project] [Problems that the invention aims to solve]

[0006] In this instance, the inventors attempted to form a vapor-deposited film on the surface of a stretched polyethylene film in order to compensate for the reduced gas barrier properties, design aesthetics, and gloss that resulted from changing from a polyester film to a stretched polyethylene film. However, they discovered a new problem: the adhesion between the stretched polyethylene film and the vapor-deposited film was insufficient, and when packaging containers were manufactured using a stretched polyethylene film with a vapor-deposited film formed on it, there was a risk of delamination occurring between the stretched polyethylene film and the vapor-deposited film.

[0007] And, surprisingly, the inventors have found that by adjusting the density of the polyethylene resin in the layer forming the vapor-deposited film of a substrate made of polyethylene resin, the adhesion between the layer and the vapor-deposited film can be significantly improved, thereby solving the above-mentioned problem.

[0008] The present invention is based on the above findings, and the problem it aims to solve is to provide a substrate for forming a vapor-deposited film that can be suitably used in the manufacture of monomaterial packaging containers, has high adhesion to vapor-deposited films, and can effectively prevent delamination when used as a packaging container.

[0009] Furthermore, the problem that the present invention aims to solve is to provide a laminate, a laminate and a packaging container equipped with the above-described substrate for forming a vapor-deposited film. [Means for solving the problem]

[0010] The substrate for forming a vapor-deposited film of the present invention comprises at least a first polyethylene resin layer on which a vapor-deposited film is formed on its surface, The density of the polyethylene resin constituting the first polyethylene resin layer is 0.943 g / cm³. 3 The following: The substrate for forming the vapor-deposited film is characterized by having been subjected to a stretching treatment.

[0011] In one embodiment, the substrate for forming a vapor deposition film has a multilayer structure, and each layer constituting the substrate for forming a vapor deposition film having a multilayer structure is made of a polyolefin resin.

[0012] In one embodiment, the densities of the polyethylene resins constituting adjacent layers are different and have a density gradient.

[0013] In one embodiment, the density difference of the polyethylene resins between the adjacent layers is 0.05 g / cm 3 or less.

[0014] The vapor deposition substrate of the present invention includes at least a substrate and a vapor deposition film. The substrate is made of the above-described substrate for forming a vapor deposition film. The vapor deposition film is provided on the first polyethylene resin layer of the substrate for forming a vapor deposition film. The first sealant layer is characterized by being made of a polyethylene resin.

[0015] The laminate of the present invention includes at least a substrate, a vapor deposition film, and a first sealant layer. The substrate is made of the above-described substrate for forming a vapor deposition film. The vapor deposition film is characterized by being provided on the first polyethylene resin layer of the substrate for forming a vapor deposition film.

[0016] In one embodiment, on the surface of the substrate opposite to the surface provided with the first sealant layer, a second sealant layer is further provided, and the second sealant layer is made of a polyethylene resin.

[0017] In one embodiment, the laminate of the present invention further includes a barrier coat layer between the first sealant layer and the vapor deposition film.

[0018] In one embodiment, the laminate of the present invention is used for a packaging container.

[0019] In one embodiment, the content of the polyethylene resin in the entire laminate is 80% by mass or more.

[0020] The packaging container of the present invention is characterized by being made of the above-mentioned laminate.

[0021] In one embodiment, the packaging container is a laminated tube. [Effects of the Invention]

[0022] According to the present invention, a substrate can be provided that can be suitably used in the production of monomaterial packaging containers, significantly improve interlayer adhesion with vapor-deposited films, and achieve desirable gas barrier properties. Furthermore, according to the present invention, it is possible to provide a vapor-deposited substrate comprising the above-described substrate and a vapor-deposited film. Furthermore, according to the present invention, it is possible to provide a packaging container comprising a laminate comprising the above-mentioned substrate, a vapor-deposited film, and a sealant layer. [Brief explanation of the drawing]

[0023] [Figure 1] This is a schematic cross-sectional view showing one embodiment of the substrate 10 for forming a vapor-deposited film according to the present invention. [Figure 2] This is a schematic cross-sectional view showing one embodiment of the vapor deposition substrate 20 of the present invention. [Figure 3] This is a schematic structural diagram showing one embodiment of a vapor deposition apparatus. [Figure 4] This is a schematic cross-sectional view showing one embodiment of the laminate 30 of the present invention. [Figure 5] This is a schematic cross-sectional view showing one embodiment of the laminate 30 of the present invention. [Figure 6] This is a front view showing a laminate tube 40, which is one embodiment of the packaging container of the present invention. [Figure 7] This is a cross-sectional view aa in Figure 6. [Figure 8] This is a front view showing a packaging bag 50, which is one embodiment of the packaging container of the present invention. [Figure 9] This is a perspective view showing a stand-up pouch 60, which is one embodiment of the packaging container of the present invention. [Modes for carrying out the invention]

[0024] (Substrate for vapor deposited film formation) The substrate for forming a vapor-deposited film of the present invention comprises a polyethylene resin layer, similar to the first and second sealant layers made of polyethylene resin described later. Thus, by having the substrate and sealant layer composed of the same resin material, the laminate can be used as a highly recyclable material for monomaterial packaging containers and the like. The substrate may be single-layered or multi-layered, as long as it has a polyethylene resin layer. However, if a multi-layered substrate is used, it can be manufactured by co-extrusion, in which each polyolefin resin, such as polyethylene resin, is heated and melted in separate extruders, and then laminated in a molten state using methods such as co-extrusion multi-layer die method or feed block method, and finally formed into a film using methods such as inflation method or T-die method.

[0025] For example, in the case of a substrate having a multilayer structure formed by co-extrusion, the substrate may have second, third, fourth, etc. polyethylene resin layers (hereinafter referred to as "other polyethylene resin layers" depending on the case) in order from the first polyethylene resin layer on the side in contact with the vapor-deposited film. By providing other polyethylene resin layers, the performance of the laminate, such as heat resistance, strength, transparency, and stretchability, can be improved.

[0026] In this invention, the substrate is characterized by being subjected to a stretching treatment. This improves the strength and heat resistance of the substrate. It also improves printability. The stretching process may be uniaxial stretching or biaxial stretching.

[0027] The stretching ratio of the substrate in the longitudinal direction (MD direction) and transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 3 times or more and 10 times or less. By increasing the stretching ratio to 2 times or more, the strength and heat resistance of the substrate can be further improved. Furthermore, the printability of the substrate can be improved. From the viewpoint of the substrate's breaking limit, a stretching ratio of 15 times or less is preferable.

[0028] In the present invention, the substrate 10 for vapor deposition film formation has a density of 0.943 g / cm³ as the layer on which the vapor deposition film is formed on its surface. 3 It comprises at least a first polyethylene resin layer 11 composed of the following polyethylene resins.

[0029] The density of the first polyethylene resin layer is 0.943 g / cm³. 3 The following polyethylene resins may be biomass-derived polyethylene resins, or polyethylene resins recycled through mechanical or chemical recycling.

[0030] Density in the first polyethylene resin layer: 0.943 g / cm³ 3 The polyethylene resin content is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Density of the first polyethylene resin layer: 0.943 g / cm³ 3 By increasing the polyethylene resin content to 50% by mass or more, the adhesion to the vapor-deposited film can be further significantly improved.

[0031] Density in the first polyethylene resin layer: 0.943 g / cm³ 3 The melting point of the polyethylene resin is preferably 60°C to 135°C, and more preferably 65°C to 130°C. Setting the melting point above 60°C can further improve the printability, strength, and heat resistance of the substrate. Setting the melting point below 135°C can reduce the difference in the appropriate stretching temperature of each layer.

[0032] Density in the first polyethylene resin layer: 0.943 g / cm³ 3The MFR of the following polyethylene resin is preferably 0.1 g / 10 min or more and 5 g / 10 min or less, and more preferably 0.2 g / 10 min or more and 4 g / 10 min or less. By setting the MFR to 0.1 g / 10 min or more and 5 g / 10 min or less, the film-forming property of the inflation method is stabilized.

[0033] The first polyethylene resin layer has a density of 0.943 g / cm 3 It can contain resin materials other than the following polyethylene resins (other resin materials). From the viewpoint of adhesion to the vapor deposition film, it is preferable that the first polyethylene resin layer does not contain other resin materials. In addition, the first polyethylene resin layer can contain additives within a range that does not impair the characteristics of the present invention. For example, crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins can be mentioned.

[0034] The other polyethylene resin layers are composed of polyethylene resin. As the polyethylene resin, high-density polyethylene resin (HDPE), medium-density polyethylene resin (MDPE), low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), and ultra-low-density polyethylene resin (VLDPE) can be used. In addition, as the polyethylene resin, a copolymer of ethylene and other monomers can also be used. Furthermore, as the polyethylene resin, a polyethylene resin derived from biomass, or a mechanically recycled or chemically recycled polyethylene resin can also be used.

[0035] In a substrate having a multilayer structure, the densities of the polyethylene resins constituting adjacent layers may be the same or different. That is, a density gradient may be provided in the polyethylene resin layer constituting the substrate. In polyethylene resin layers with a density gradient, if the density difference between each layer is large, delamination may occur at the interface. Therefore, the density difference between each layer should be 0.05 g / cm³. 3 Preferably, it is 0.04 g / cm³. 3 The following is even more preferable:

[0036] (a) In one embodiment, the substrate having a multilayer structure has a five-layer structure comprising a first polyolefin resin layer, a second polyethylene resin layer made of medium-density polyethylene resin, a third polyethylene resin layer made of linear low-density polyethylene resin, a fourth polyethylene resin layer made of medium-density polyethylene resin, and a fifth polyolefin resin layer made of high-density polyethylene resin. (b) In one embodiment, the substrate having a multilayer structure has a seven-layer structure comprising: a first polyethylene resin layer; a second resin layer composed of a blend of high-density polyethylene resin and medium-density polyethylene resin; a third polyethylene resin layer composed of medium-density polyethylene resin; a fourth polyethylene resin layer composed of linear low-density polyethylene resin; a fifth polyethylene resin layer composed of medium-density polyethylene resin; a sixth resin layer composed of a blend of high-density polyethylene resin and medium-density polyethylene resin; and a seventh polyolefin resin layer composed of high-density polyethylene resin. (c) In one embodiment, the substrate having a multilayer structure has a three-layer structure comprising a first polyethylene resin layer, a second polyethylene resin layer composed of linear low-density polyethylene resin, and a third polyolefin resin layer composed of medium-density polyethylene resin. (d) In one embodiment, the substrate having a multilayer structure has a two-layer structure comprising a first polyethylene resin layer and a second polyolefin resin layer made of medium-density polyethylene resin. (e) In one embodiment, the substrate having a multilayer structure has a five-layer structure comprising: a first polyethylene resin layer containing an olefin-based elastomer resin; a second polyolefin resin layer made of a medium-density polyethylene resin; a third polyolefin resin layer made of a linear low-density polyethylene resin; a fourth polyolefin resin layer made of a medium-density polyethylene resin; and a fifth polyolefin resin layer made of an olefin-based elastomer resin and a medium-density polyethylene resin.

[0037] As one embodiment of the multilayer substrate produced by the co-extrusion method described above, for example, each resin can be heated and melted in an extruder, and five layers consisting of the first to fifth polyethylene resin layers can be laminated using the feed block method. Then, the layers can be formed into a tube shape using the inflation method, and the insides of the tubes can be pressed together with rubber rolls or the like to produce a 10-layer multilayer film. The multilayer film thus obtained will have a layer structure that is vertically symmetrical in the thickness direction of the cross-section. That is, for example, when five layers consisting of the first to fifth polyethylene resin layers are laminated using a co-extruder, the resulting laminated film will be a substrate with a 10-layer structure consisting of the first / second / third / fourth / fifth / fifth / fourth / third / second / first polyethylene resin layers in order from the surface. However, in reality, since the two adjacent fifth polyethylene resin layers in the center can be considered as one layer in the thickness cross-sectional direction, the substrate can effectively have a 9-layer multilayer structure consisting of the first / second / third / fourth / fifth / fourth / third / second / first polyethylene resin layers. The multilayer film obtained by this manufacturing method is sometimes called "block film." According to the above method, the number of defective products in manufacturing can be significantly reduced, ultimately improving production efficiency.

[0038] The substrate may have a printed layer on its surface, and the image formed on the printed layer is not particularly limited and may represent characters, patterns, symbols, or combinations thereof. The printing layer on the substrate can be formed using biomass-derived ink. This reduces the environmental impact. The method for forming the printed layer is not particularly limited and can be described as conventionally known printing methods such as gravure printing, offset printing, and flexographic printing.

[0039] Furthermore, the substrate may be surface-treated. This can improve adhesion with adjacent layers. The surface treatment method is not particularly limited and includes physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0040] The thickness of the substrate is preferably 1 μm to 60 μm, more preferably 9 μm to 60 μm, and even more preferably 12 μm to 50 μm, regardless of whether it is a single-layer or multi-layer structure. By making the substrate thickness 1 μm or more, the heat resistance and strength of the substrate can be improved. By making the substrate thickness 60 μm or less, the processability of the substrate can be improved.

[0041] (vapor deposition base material) As shown in Figure 2, the vapor deposition substrate 20 of the present invention comprises the vapor deposition film forming substrate 10 and a vapor deposition film 21, characterized in that the vapor deposition film 21 is provided on the first polyethylene resin layer 11.

[0042] The following describes each layer of the vapor deposition substrate. Note that the vapor deposition film-forming substrate 10 has been described above and will not be described here.

[0043] (Vaporized film) The vapor-deposited substrate comprises a vapor-deposited film on a first polyethylene resin layer. This improves the gas barrier properties of the vapor-deposited substrate, specifically its oxygen barrier properties and water vapor barrier properties.

[0044] The vapor-deposited film 21 may be composed of a metal or an inorganic oxide, but a vapor-deposited film composed of a metal (hereinafter referred to as a metal vapor-deposited film) is preferred because it can impart a glossy appearance to the container made using the vapor-deposited substrate of the present invention and improve its design. Examples of metals that make up a metal vapor-deposited film include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Examples of metal oxides include aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide.

[0045] Among the materials mentioned above, aluminum is particularly preferred because it has high gas barrier properties and can provide a good gloss.

[0046] It is preferable that the surface of the deposited film is subjected to the above-mentioned surface treatment. This improves adhesion with adjacent layers.

[0047] Furthermore, the thickness of the deposited film is preferably 1 nm to 150 nm, more preferably 5 nm to 60 nm, and even more preferably 10 nm to 40 nm. By making the thickness of the deposited film 1 nm or more, the gas barrier properties and glossiness of the deposited substrate can be further improved. Furthermore, by setting the thickness of the vapor-deposited film to 150 nm or less, it is possible to create a vapor-deposited substrate that can be suitably used for the production of monomaterial packaging containers. In addition, it is possible to prevent the occurrence of cracks in the vapor-deposited film 21.

[0048] Conventional known methods can be used to form the deposited film, such as physical vapor deposition (PVD) methods including vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD) methods including plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition. The following describes one embodiment of a method for forming a vapor-deposited film, but the method for forming a vapor-deposited film is not limited to this.

[0049] Specifically, a vapor-deposited film can be formed using (1) a vacuum deposition method in which a metal or metal oxide is used as a raw material, heated to vaporize it, and deposited onto a first polyethylene resin layer provided on a substrate; (2) an oxidation reaction deposition method in which a metal or metal oxide is used as a raw material, oxygen is introduced to oxidize it, and it is deposited onto a first polyethylene resin layer provided on a substrate; or (3) a plasma-assisted oxidation reaction deposition method in which the oxidation reaction is assisted by plasma. In the above, the heating method for the deposition material can be, for example, a resistance heating method, a high-frequency induction heating method, an electron beam heating method (EB), etc.

[0050] The following describes a method for forming deposited films of inorganic materials and inorganic oxides by physical vapor deposition. Figure 3 is a schematic diagram showing an example of a roll-up type vacuum deposition apparatus. As shown in Figure 3, in the vacuum chamber B of the roll-up type vacuum deposition apparatus A, the substrate X unwound from the unwinding roll C is guided to the cooled coating drum F via guide rolls D and E. In one embodiment, the apparatus A has a plasma processing device G positioned between the guide roll E and the cooled coating drum F. The plasma processing device G irradiates the surface of the first polyethylene resin layer on the substrate X with plasma gas, thereby plasma-treating the surface of the first polyethylene resin layer on the substrate X before the deposition film is formed. Next, a vapor deposition source I (e.g., metallic aluminum or aluminum oxide, etc.) heated and evaporated in the crucible H is deposited on the first polyethylene resin layer of the substrate guided onto the cooled coating drum F, forming a vapor-deposited film. This deposition of the vapor deposition source I may be carried out via masks J, J, and further, if necessary, while blowing oxygen gas or the like from an oxygen gas outlet K. Next, the substrate X on which the vapor-deposited film has been formed is fed through guide rolls L and M and wound onto a winding roll N, thereby completing the vapor-deposited film formation process using this apparatus. Furthermore, by repeating the above process, a multilayer vapor-deposited film made of different materials may be formed. The multilayer vapor-deposited film may be formed by using the above apparatus twice, or by using an apparatus that connects the above apparatus. The formation of such a vapor-deposited film is disclosed, for example, in Japanese Patent Publication No. 4569982.

[0051] (Laminated structure) As shown in Figure 4, the laminate 30 of the present invention comprises at least a substrate 10 for forming a vapor-deposited film, a vapor-deposited film 21, and a first sealant layer 31. In one embodiment, as shown in Figure 8, the laminate 30 includes a second sealant layer 32 on the side of the deposition film forming substrate 10 opposite to the first sealant layer 31. The laminate 30 may also have a barrier coat layer on the vapor-deposited film 21 (not shown).

[0052] The polyethylene content relative to the total amount of solids in the laminate is preferably 80% by mass or more, and more preferably 90% by mass or more. This makes it possible to create a laminate that can be suitably used in the manufacture of monomaterial packaging containers.

[0053] The following describes each layer of the laminate. Note that the substrate for vapor deposition film formation and the vapor deposition film have been described above, so they are omitted here.

[0054] (First and second sealant layers) The first and second polyolefin resin layers are composed of polyolefins, such as polyethylene resin, polypropylene resin, polymethylpentene, ethylene-propylene copolymer, and propylene-butene copolymer. Among these, polyethylene resin is preferred from the viewpoint of recyclability.

[0055] In one embodiment, the first and second polyolefin resin layers contain a compatibilizer, which effectively prevents the gas barrier resin and polyethylene resin from uniformly mixing and degrading their physical properties when a packaging container made using the laminate of the present invention is heated, melted, and recycled. It also effectively prevents a decrease in its transparency.

[0056] While conventionally known compatibilizers can be appropriately selected and used, unsaturated carboxylic acid-modified polyolefin resins are preferred from the viewpoint of recyclability, and among these, maleic anhydride-modified polyethylene resins are more preferred.

[0057] The content of the compatibilizer in the first and second polyolefin resin layers is preferably 5% by mass or more and 30% by mass or less. The above effect can be further improved by increasing the compatibilizer content in the first and second polyolefin resin layers to 5% by mass or more. By setting the compatibilizer content in the first and second polyolefin resin layers to 30% by mass or less, the strength and heat resistance of the substrate can be improved.

[0058] Within the limits that do not impair the properties of the present invention, the first and second polyethylene resin layers may contain resin materials other than polyolefin resin, such as (meth)acrylic resin, vinyl resin, cellulose resin, polyamide resin, polyester resin, and ionomer resin. Furthermore, from the standpoint of their recyclability, it is particularly preferable that the first and second polyolefin resin layers do not contain any resins other than polyethylene resin.

[0059] Furthermore, the first and second polyethylene resin layers may contain the above-mentioned additives, to the extent that they do not impair the properties of the present invention.

[0060] The thickness of the first and second polyolefin resin layers is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. By making the thickness of the polyolefin resin layer 5 μm or more, the strength and heat resistance of the laminate of the present invention can be improved. By making the thickness of the polyolefin resin layer 100 μm or less, the processability of the laminate of the present invention can be improved.

[0061] The first and second polyolefin resin layers may be identical or different in composition.

[0062] (Barrier coat layer) The vapor-deposited substrate of the present invention may further include a barrier coat layer on the vapor-deposited film (between the first sealant layer and the vapor-deposited film, or between the vapor-deposited film and the substrate). This improves the gas barrier properties of the vapor-deposited substrate.

[0063] In one embodiment, the barrier coat layer is composed of polyamide resins such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6 and polymethoxylylene adipamide (MXD6), polyester resins, polyurethane resins, and gas barrier resins such as (meth)acrylic resins.

[0064] The thickness of the barrier coat layer is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less. By making the barrier coating layer thickness 0.01 μm or more, the gas barrier properties can be further improved. By making the barrier coating layer thickness 10 μm or less, the processability of the vapor-deposited substrate can be improved. Furthermore, it can be used as a vapor-deposited substrate that is suitable for the manufacture of monomaterial packaging containers.

[0065] The barrier coating layer can be formed by dissolving or dispersing the above material in water or a suitable solvent, applying it, and drying it.

[0066] In another embodiment, the barrier coating layer is a gas barrier coating film containing at least one resin composition, such as a hydrolyzed metal alkoxide or a hydrolyzed condensate of a metal alkoxide, obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel catalyst, water, and an organic solvent. By providing such a barrier coating layer on the vapor-deposited film, the occurrence of cracks in the vapor-deposited film can be effectively prevented.

[0067] In one embodiment, the metal alkoxide is represented by the following general formula. R 1 n M(OR 2 ) m (However, in the formula, R 1 , R 2 (Each represents an organic group with 1 to 8 carbon atoms, M represents a metal atom, n represents a non-negative integer, m represents a non-negative integer, and n+m represents the valence of M.)

[0068] Examples of metal atoms M that can be used include silicon, zirconium, titanium, and aluminum. Also, R 1 and R 2 Examples of organic groups represented by include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, and i-butyl groups.

[0069] Examples of metal alkoxides that satisfy the above general formula include tetramethoxysilane (Si(OCH3)4), tetraethoxysilane (mass%) Si(OC2H5)4), tetrapropoxysilane (Si(OC3H7)4), and tetrabutoxysilane (Si(OC4H9)4).

[0070] Furthermore, it is preferable to use a silane coupling agent together with the above-mentioned metal alkoxide. As the silane coupling agent, known organoalkoxysilanes containing organic reactive groups can be used.

[0071] As water-soluble polymers, polyvinyl alcohol and ethylene-vinyl alcohol copolymers are preferred, and from the viewpoint of oxygen barrier properties, water vapor barrier properties, water resistance and weather resistance, it is preferable to use these in combination.

[0072] The thickness of the gas barrier coating film is preferably 0.01 μm to 10 μm, and more preferably 0.1 μm to 5 μm. This allows for further improvement of the gas barrier properties. By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier and water vapor barrier properties of the barrier laminate can be improved. Furthermore, the occurrence of cracks in the vapor-deposited film can be prevented. By setting the thickness of the gas barrier coating film to 10 μm or less, a vapor deposition substrate suitable for use in the production of monomaterial packaging containers can be obtained.

[0073] A gas barrier coating film can be formed by applying a composition containing the above-mentioned materials using conventionally known methods such as roll coating (including gravure roll coaters), spray coating, spin coating, dipping, brushing, barcode application, or applicator application, and then polycondensing the composition by a sol-gel method. Acid or amine compounds are preferred as catalysts for the sol-gel process.

[0074] The above composition may further contain an acid. The acid is used as a catalyst for the sol-gel process, mainly as a catalyst for the hydrolysis of alkoxides and silane coupling agents. As acids, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, as well as organic acids such as acetic acid and tartaric acid, are used.

[0075] Furthermore, the above composition may contain an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butanol.

[0076] The following describes one embodiment of a method for forming a gas barrier coating film. First, a composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually proceeds within this composition. Next, the composition is applied to the vapor-deposited film and dried using the conventionally known method described above. This drying further promotes the polycondensation reaction between the alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains one), forming a composite polymer layer. Finally, heating allows for the formation of a gas barrier coating film.

[0077] (packaging container) The packaging container of the present invention is characterized by being made of the above-described laminate.

[0078] Specific examples of the packaging container of the present invention include laminate tubes, packaging bags, and lid materials.

[0079] (Laminated tube) In one embodiment, the packaging container of the present invention is a laminated tube. The laminate tube 40 of the present invention will be described below with reference to the drawings. Figure 6 is a simplified diagram showing the structure of the laminate tube 40, and Figure 7 is a cross-sectional view of aa in Figure 6. As shown in Figure 6, the laminate tube 40 comprises a laminate tube body 41 having a head portion 42 and a body portion 43, and the body portion 43 is characterized in that it is made of the laminate 30 described above.

[0080] (head) The head portion 42 includes a shoulder portion 44 connected to one end of the torso portion 43, and an extraction port portion 45 connected to the shoulder portion 44. In one embodiment, the spout portion 45 is provided with threads 47 for screwing on the cap 46.

[0081] In one embodiment, the head portion 42 is made of polyethylene resin, which improves the recyclability of the laminate tube. As the polyethylene resin, high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, and ultra-low-density polyethylene resin can be used. Among these, high-density polyethylene resin is preferred from the standpoint of shape retention. Furthermore, as the polyethylene resin, polyethylene resin derived from biomass or polyethylene resin recycled through mechanical or chemical recycling can be used. The head 42 may contain the above-mentioned additives, to the extent that it does not impair the specification of the present invention.

[0082] The manufacturing method for the head 42 is not particularly limited and can be manufactured by conventionally known methods. For example, the head 42 can be manufactured by compression molding or injection molding and then joined to the body.

[0083] When manufacturing a laminate tube 40 using a compression molding method, the body portion 43 is attached to a male mold having a protrusion at the top, the male and female molds are placed opposite each other, and molten polyethylene resin or other material is supplied into the male and female molds and compressed to form the head portion 42, which is then joined to one opening of the body portion 43, thereby manufacturing a laminate tube 40 consisting of the head portion 42 and the body portion 43. Furthermore, when manufacturing the laminate tube 40 using injection molding, the body portion 43 is attached to a male mold having a protrusion at the top, the male and female molds are placed opposite each other, molten polyethylene resin or other material is supplied from the gate, and the head portion 42 is formed by injection molding and joined to one opening of the body portion 43, thereby manufacturing a laminate tube consisting of the head portion 42 and the body portion 43.

[0084] (torso) In the laminate tube body 41 of the present invention, the torso portion 43 is connected to the shoulder portion 44 of the head portion 42. The body portion 43 can be obtained by rolling the laminated body 30 into a cylindrical shape, overlapping the first sealant layer 31 and the second sealant layer 32, and forming a welded portion 48 by heat sealing the overlapped portion. Furthermore, the body portion 43 includes a bottom seal portion 49 formed by heat-sealing the opening of the rolled laminate 30.

[0085] Heat sealing can be performed using conventionally known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, ultrasonic sealing, and flame sealing.

[0086] (cap) The laminated tube 40 may be equipped with a cap 46. The cap is detachably attached to the dispensing opening at the top of the dispenser and serves to close the dispensing opening. The cap is made of thermoplastic resin. Examples of thermoplastic resins include polyethylene and polyolefin resins such as polypropylene, polyester, cellulose resin, and vinyl resin, but polyethylene resin is particularly preferred from the standpoint of recyclability. Furthermore, the cap 46 may also contain the above-mentioned additives, to the extent that it does not impair the properties of the present invention.

[0087] As shown in Figure 6, the cap may be a screw-type cap with a groove on the inner surface of the cap 46 so as to screw onto the threads 47 of the dispensing port 45, or it may be a cap-type cap that is fitted by pressing it into the dispensing port 47.

[0088] In one embodiment, the packaging container of the present invention is a packaging bag. Examples of packaging bags include various types such as standing pouch type, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope seal type, gusset seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.

[0089] In one embodiment, the packaging container of the present invention is a packaging bag 50 formed by bonding two laminated materials together, as shown in Figure 8 (the shaded area is a heat-sealed portion).

[0090] A packaging bag 50 in the form shown in Figure 8 can be manufactured by preparing two laminates 30, overlapping these laminates 30 so that the first sealant layers 31 face each other, and heat-sealing three sides.

[0091] In one embodiment, the packaging container of the present invention is a standing pouch type packaging bag 60 (hereinafter simply referred to as a standing pouch 60), as shown in Figure 9, and the standing pouch 60 comprises a body portion 61 and a bottom portion 62. The body 61 of the standing pouch 60 is made of a laminate 30. Furthermore, the bottom portion 62 may also be made of the laminated body 30. By adopting such a configuration, the gas barrier properties of the standing pouch 60 can be further improved.

[0092] The body portion 61 can be formed by manufacturing a bag such that the first sealant layer 31 provided by the base material and laminate 30 becomes the innermost layer. In another embodiment, two laminates 30 are prepared first, and they are stacked on top of each other with the first sealant layer 31 facing each other. Then, two V-shaped folded laminates 30 are inserted from both ends of the stacked laminates 30, with the first sealant layer 31 facing outwards, and the body 61 of the standing pouch 60 can be formed by heat sealing. This manufacturing method allows for the creation of a stand pouch 60 having a body with side gussets. Furthermore, the bottom portion 62 can be formed by inserting the laminate 30 between the formed body portions 61 and heat sealing it. More specifically, the laminate 30 can be formed by folding it in a V-shape so that the first sealant layer 31 faces outwards, inserting it between the formed body portions 61, and heat sealing it.

[0093] Furthermore, the packaging container may be equipped with an easy-opening mechanism 71, as shown in Figure 8. Examples of the easy-opening means 71 include a notch portion 72 that serves as the starting point for tearing, as shown in Figure 8, and a half-cut line 73 formed by laser processing or a cutter as a path for tearing.

[0094] Furthermore, the packaging container may be equipped with a steam venting mechanism 80, as shown in Figure 9. The steam venting mechanism 80 is configured to connect the inside and outside of the packaging container and release steam when the steam pressure inside the packaging container exceeds a predetermined value, while also preventing steam from escaping at locations other than the steam venting mechanism 80. The steam venting mechanism 80 includes a steam venting seal portion 80a that protrudes from the side seal portion toward the inside of the packaging container, and an unsealed portion 80b that is isolated from the contents storage portion by the steam venting seal portion 80a. The unsealed portion 80b is in communication with the outside of the packaging. When the packaging container, which is filled with contents and has its opening heat-sealed, is heated in a microwave oven or the like, the internal pressure increases, causing the steam seal portion 80a to detach. The steam escapes through the detached portion of the steam seal 80a and the unsealed portion 70b to the outside of the packaging container. [Examples]

[0095] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The materials used in the following examples are as follows: • Polyethylene resin A: Manufactured by Prime Polymer, SP0523A, m-C6-LLDPE, density 0.908 g / cm³ 3 Melting point 104℃, MFR 2.0g / 10min. Polyethylene resin B: Dow Chemical, ELITE5538G, MDPE, density 0.941g / cm³. 3 Melting point 129℃, MFR 1.3g / 10min, polyethylene resin C: manufactured by Prime Polymer, SP2520, m-C6-LLDPE, density 0.925g / cm³ 3 Melting point 122℃, MFR 1.9g / 10min • Polyethylene resin D: Dow Chemical, ELITE5100G, HDPE, density 0.920 g / cm³ 3 Melting point 122℃, MFR 0.85g / 10min, polyethylene resin E: Dow Chemical, Affinity PL1880G, m-C8-LLDPE, density 0.902g / cm³ 3 Melting point 99℃, MFR 1.0g / 10min • Polyethylene resin a: Manufactured by Prime Polymer, HZ3300, density 0.950 g / cm³ 3 HDPE, melting point 132℃, MFR 1.1g / 10min • Polyethylene resin b: Dow Chemical, ELITE5960G, HDPE, density 0.962 g / cm³ 3 Melting point 134℃, MFR 0.85g / 10min

[0096] Example 1-1 Polyethylene resin A and polyethylene resin B were co-extruded in two layers by an inflation method, and then stretched five times in the longitudinal (MD) direction to produce a substrate 10 for vapor deposition film formation, comprising a first polyethylene resin layer 11 composed of polyethylene resin A and a second polyethylene resin layer 12 composed of polyethylene resin B. In the substrate 10 for vapor deposition film formation, the thickness of the first polyethylene resin layer 11 was 2 μm, and the thickness of the second polyethylene resin layer 12 was 23 μm.

[0097] A 30 nm thick aluminum vapor-deposited film was formed on the first polyethylene resin layer 11 of the vapor-deposited film-forming substrate 10 prepared as described above, by PVD (Physical Vapor Deposition) method, thereby creating a vapor-deposited substrate. The optical density (OD value) of the formed vapor-deposited film was measured to be 3.0.

[0098] Examples 1-2 to 1-4 and Comparative Examples 1-1 to 1-2 Except for changing the polyethylene resin A used to form the first polyethylene resin layer 11 to the polyethylene resin shown in Table 1, a vapor deposition film forming substrate 10 and a vapor deposition substrate were prepared in the same manner as in Example 1-1.

[0099] <<Laminate Strength Evaluation>> Polyethylene resin C was extruded as a single layer by the inflation method to obtain an unstretched polyethylene resin film with a thickness of 100 μm. This unstretched polyethylene resin film was used as the first sealant layer 31 and laminated onto the vapor-deposited film 21 of the vapor-deposited substrate obtained in Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-2 via a two-component curing urethane adhesive (manufactured by Rock Paint Co., Ltd., RU-004 / H-1) to produce a laminate 30.

[0100] The laminate 30 prepared as described above was cut into strips 15 mm wide to serve as test specimens. The peel force between the vapor-deposited film 21 and the first polyethylene resin layer 11 in this test specimen was measured using a tensile tester (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.) in accordance with JIS K 6854-2. The measurement results are shown in Table 1. The peeling speed was set to 50 mm / min, and the peeling angle to 180°.

[0101] Example 2-1 Polyethylene resin A, polyethylene resin B, and polyethylene resin A were co-extruded into a three-layer film by inflation, and then stretched five times in the longitudinal (MD) direction to produce a substrate 10 for vapor deposition film formation, comprising a first polyethylene resin layer 11 made of polyethylene resin A, a second polyethylene resin layer 12 made of polyethylene resin B, and a third polyethylene resin layer 13 made of polyethylene resin A. In the substrate 10 for vapor deposition film formation, the thickness of the first polyethylene resin layer 11 was 2 μm, the thickness of the second polyethylene resin layer 12 was 21 μm, and the thickness of the third polyethylene resin 13 was 2 μm.

[0102] A 30 nm thick aluminum vapor-deposited film was formed on the first polyethylene resin layer 11 of the vapor-deposited film-forming substrate 10 prepared as described above, by PVD (Physical Vapor Deposition) method, thereby creating a vapor-deposited substrate. The optical density (OD value) of the formed vapor-deposited film was measured to be 3.0.

[0103] Examples 2-2 to 2-4 and Comparative Examples 2-1 to 2-2 A vapor deposition film-forming substrate 10 and a vapor deposition substrate were prepared in the same manner as in Example 2-1, except that the polyethylene resin A used to form the first polyethylene resin layer 11 and the third polyethylene resin layer 13 was changed to the polyethylene resin shown in Table 2.

[0104] <<Laminate Strength Evaluation>> Polyethylene resin C was extruded as a single layer by the inflation method to obtain an unstretched polyethylene resin film with a thickness of 100 μm. This unstretched polyethylene resin film was used as the first sealant layer 31 and laminated onto the vapor-deposited film 21 of the vapor-deposited substrate obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-2 via a two-component curing urethane adhesive (manufactured by Rock Paint Co., Ltd., RU-004 / H-1) to produce a laminate 30.

[0105] The laminate 30 prepared as described above was cut into strips 15 mm wide to serve as test specimens. The peel force between the vapor-deposited film 21 and the first polyethylene resin layer 11 in this test specimen was measured using a tensile tester (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.) in accordance with JIS K 6854-2. The measurement results are shown in Table 2. The peeling speed was set to 50 mm / min, and the peeling angle to 180°.

[0106] Example 3-1 Polyethylene resin A was extruded into a single layer by the inflation method, and then stretched five times in the longitudinal (MD) direction to produce a substrate 10 for vapor deposition film formation consisting of a first polyethylene resin layer 11 made of polyethylene resin A. In the substrate 10 for vapor deposition film formation, the thickness of the first polyethylene resin layer 11 was 25 μm.

[0107] A 30 nm thick aluminum vapor-deposited film was formed on the first polyethylene resin layer 11 of the vapor-deposited film-forming substrate 10 prepared as described above, by PVD (Physical Vapor Deposition) method, thereby creating a vapor-deposited substrate.

[0108] Examples 3-2 to 3-4 and Comparative Examples 3-1 to 3-2 Except for changing the polyethylene resin A used to form the first polyethylene resin layer 11 to the polyethylene resin shown in Table 3, a vapor deposition film forming substrate 10 and a vapor deposition substrate were prepared in the same manner as in Example 3-1.

[0109] <<Laminate Strength Evaluation>> Polyethylene resin C was extruded as a single layer by the inflation method to obtain an unstretched polyethylene resin film with a thickness of 100 μm. This unstretched polyethylene resin film was used as the first sealant layer 31 and laminated onto the vapor-deposited film 21 of the vapor-deposited substrate obtained in Examples 3-1 to 3-4 and Comparative Examples 3-1 to 3-2 via a two-component curing urethane adhesive (manufactured by Rock Paint Co., Ltd., RU-004 / H-1) to produce a laminate 30.

[0110] The laminate 30 prepared as described above was cut into strips 15 mm wide to serve as test specimens. The peel force between the vapor-deposited film 21 and the first polyethylene resin layer 11 in this test specimen was measured using a tensile tester (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.) in accordance with JIS K 6854-2. The measurement results are shown in Table 3. The peeling speed was set to 50 mm / min, and the peeling angle to 180°.

[0111] Example 4-1 Polyethylene resins A, B, and E are co-extruded by the inflation method to form a three-layered tube consisting of a layer made of polyethylene resin A (outer layer), a layer made of polyethylene resin B (intermediate layer), and a layer made of polyethylene resin E (inner layer). Next, the inner layers, each made of polyethylene resin E, were pressed together using a rubber roll to obtain a five-layer film comprising a first polyethylene resin layer 11 made of polyethylene resin A, a second polyethylene resin layer 12 made of polyethylene resin B, a third polyethylene resin layer 13 made of polyethylene resin E, a fourth polyethylene resin layer 14 made of polyethylene resin B, and a fifth polyethylene resin layer 15 made of polyethylene resin A. This film was stretched five times in the longitudinal (MD) direction to produce a substrate 10 for vapor deposition film formation. In the substrate 10 for vapor deposition film formation, the thickness of the first polyethylene resin layer 11 was 2 μm, the thickness of the second polyethylene resin layer 12 was 9.3 μm, the thickness of the third polyethylene resin 13 was 2.4 μm, the thickness of the fourth polyethylene resin layer 14 was 9.3 μm, and the thickness of the fifth polyethylene resin 15 was 2 μm.

[0112] A 30 nm thick aluminum vapor-deposited film was formed on the first polyethylene resin layer 11 of the vapor-deposited film-forming substrate 10 prepared as described above, by PVD (Physical Vapor Deposition) method, thereby creating a vapor-deposited substrate. The optical density (OD value) of the formed vapor-deposited film was measured to be 3.0.

[0113] Examples 4-2 to 4-4 and Comparative Examples 4-1 to 4-2 A vapor deposition film-forming substrate 10 and a vapor deposition substrate were prepared in the same manner as in Example 4-1, except that polyethylene resin A used to form the first polyethylene resin layer 11 and the fifth polyethylene resin layer 15 was changed to the polyethylene resin shown in Table 4.

[0114] <<Laminate Strength Evaluation>> Polyethylene resin C was extruded as a single layer by the inflation method to obtain an unstretched polyethylene resin film with a thickness of 100 μm. This unstretched polyethylene resin film was used as the first sealant layer 31 and laminated onto the vapor-deposited film 21 of the vapor-deposited substrate obtained in Examples 4-1 to 4-4 and Comparative Examples 4-1 to 4-2 via a two-component curing urethane adhesive (RU-004 / H-1, manufactured by Rock Paint Co., Ltd.) to produce a laminate 30.

[0115] The laminate 30 prepared as described above was cut into strips 15 mm wide to serve as test specimens. The peel force between the vapor-deposited film 21 and the first polyethylene resin layer 11 in this test specimen was measured using a tensile tester (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.) in accordance with JIS K 6854-2. The measurement results are shown in Table 4. The peeling speed was set to 50 mm / min, and the peeling angle to 180°.

[0116] [Table 1]

[0117] [Table 2]

[0118] [Table 3]

[0119] [Table 4] [Explanation of Symbols]

[0120] 10: Substrate for vapor deposition film formation, 11: First polyethylene resin layer, 12: Second polyethylene resin layer, 13: Third polyethylene resin layer, 14: Fourth polyethylene resin layer, 15: Fifth polyethylene resin layer, 20: Vapor deposition substrate, 21: Vapor deposition film, 30: Laminate, 31: First sealant layer, 32: Second sealant layer, 40: Laminate tube, 41: Laminate tube body, 42: Head, 43: Body, 44: Shoulder, 45: Outlet, 46: Cap, 47: Thread, 48: Welded part, 49: Bottom seal part, 50: Packaging bag, 60: Standing pouch, 61: Body, 62: Bottom, 71: Easy opening means, 72: Notch, 73: Half-cut line, 80: Steam venting mechanism, 80a: Steam venting seal part, 80b: Unsealed part

Claims

1. A laminate comprising at least a substrate, a vapor-deposited film, and a first sealant layer, A second sealant layer is further provided on the surface of the substrate opposite to the surface on which the first sealant layer is provided. The substrate is made of a substrate for forming a vapor-deposited film, The aforementioned substrate for forming a vapor-deposited film has a multilayer structure, Each layer constituting the substrate for forming the vapor-deposited film is made of polyethylene resin. The density of the polyethylene resin constituting each of the aforementioned layers is different. Of the aforementioned layers, the density of the polyethylene resin constituting the first polyethylene resin layer that constitutes the surface of the vapor-deposited film-forming substrate is 0.943 g / cm³ or less. The substrate for forming the vapor-deposited film has been subjected to a stretching treatment. The vapor-deposited film is provided on the first polyethylene resin layer of the substrate for forming the vapor-deposited film. A laminate characterized in that the first sealant layer and the second sealant layer are made of polyethylene resin.

2. The laminate according to claim 1, further comprising a barrier coat layer between the first sealant layer and the vapor-deposited film.

3. A laminate according to claim 1 or 2, used in a packaging container.

4. The laminate according to any one of claims 1 to 3, wherein the polyethylene resin content in the entire laminate is 80% by mass or more.

5. A packaging container comprising a laminate according to any one of claims 1 to 4.

6. The packaging container according to claim 5, which is a laminated tube.

7. A packaging container for laminate tubes made of a laminate, The laminate comprises at least a substrate, a vapor-deposited film, and a first sealant layer. The substrate is made of a substrate for forming a vapor-deposited film, The aforementioned substrate for forming a vapor-deposited film has a multilayer structure, Each layer constituting the substrate for forming the vapor-deposited film is made of polyethylene resin. The density of the polyethylene resin constituting each of the aforementioned layers is different. Of the aforementioned layers, the density of the polyethylene resin constituting the first polyethylene resin layer that constitutes the surface of the vapor-deposited film-forming substrate is 0.943 g / cm³ or less. The substrate for forming the vapor-deposited film has been subjected to a stretching treatment. The vapor-deposited film is provided on the first polyethylene resin layer of the substrate for forming the vapor-deposited film. A packaging container for laminate tubes, characterized in that the first sealant layer is made of polyethylene resin.

8. The packaging container for a laminate tube according to claim 7, further comprising a barrier coat layer between the first sealant layer and the vapor-deposited film.

9. The packaging container for laminate tubes according to claim 7 or 8, wherein the polyethylene resin content in the entire laminate is 80% by mass or more.

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