Laminate and tube container body

Abstract

To provide a laminate from which a tube container body having high recyclability can be produced. [Solution] The laminate of the present invention comprises a surface resin layer, a substrate, a gas barrier layer, and a heat seal layer, wherein the surface resin layer, the substrate, and the heat seal layer are made of the same material, the substrate has a vapor-deposited film on at least one surface, the surface resin layer has heat sealability, and the same material is polyethylene.

Description

[Technical Field]

[0001] The present invention relates to a laminate and a tube container body including the laminate.

[0002] Tube containers, which include a tube container body and a cap, are known as packaging containers that are filled with semi-liquid paste-like materials such as toothpaste and facial cleansing cream and then squeezed out for use. The tube container body generally has a structure including a cylindrical body portion that is closed at one end and open at the other end, and a head portion that has a spout connected to the other open end of the body portion. After the body portion is filled with the contents, the tube container containing the contents is manufactured by closing the one end. As a laminate constituting the barrel of a tube container body, a laminate of a polyethylene film, a polyester film, a gas barrier layer, an aluminum foil, etc. is widely used (for example, Patent Documents 1 and 2, etc.).

[0003] In recent years, with the growing demand for a recycling-oriented society, there has been a demand for packaging containers with high recyclability. However, as mentioned above, the body portion of conventional tube containers is made up of a laminate with multiple layers of different materials, and since it is difficult to separate the layers of different materials, they are not currently recycled. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-282184 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-231372 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a laminate that can be used to produce a tube container body that has high recyclability. Another object of the present invention is to provide a tube container body including the laminate. [Means for solving the problem]

[0006] The laminate of the present invention comprises a surface resin layer, a substrate, a gas barrier layer, and a heat seal layer, The surface resin layer, the substrate, and the heat seal layer are made of the same material, The substrate has a vapor-deposited film on at least one surface thereof, the surface resin layer has heat sealing properties, The uniform material is characterized by being polyethylene.

[0007] In one embodiment, the laminate of the present invention comprises a melt-extruded polyethylene layer or an adhesive layer between at least one of the following: the surface resin layer and the substrate; the substrate and the gas barrier layer; and the gas barrier layer and the heat seal layer.

[0008] In one embodiment, the polyethylene constituting the surface resin layer and the heat seal layer is low-density polyethylene and / or linear low-density polyethylene.

[0009] In one embodiment, the vapor-deposited film is a vapor-deposited metal film.

[0010] In one embodiment, the gas barrier layer comprises a first polyethylene resin layer, a first adhesive layer, a layer containing a gas barrier resin, a second adhesive layer, and a second polyethylene resin layer.

[0011] In one embodiment, the thickness of the layer containing the gas barrier resin is 5 μm or more and 30 μm or less.

[0012] In one embodiment, the thickness of the surface resin layer and the heat seal layer is 50 μm or more and 150 μm or less.

[0013] In one embodiment, the thickness of the substrate is 10 μm or more and 50 μm or less.

[0014] In one embodiment, the thickness of the deposited film is 1 nm or more and 150 nm or less.

[0015] In one embodiment, the content of polyethylene in the entire laminate is 90% by mass or more.

[0016] In one embodiment, the laminate of the present invention is used in a tube container application.

[0017] The tube container of the present invention comprises a head portion and a body portion, The head portion has a shoulder portion connected to one end of the body portion and a spout portion connected to the shoulder portion, The body is characterized by being formed from the laminate.

[0018] In one embodiment, the head portion is made of a resin composition containing polyethylene.

[0019] In one embodiment, the tube container further includes a cap made of a resin composition containing polyethylene. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a laminate from which a tube container having high recyclability can be produced, and also to provide a tube container body having high recyclability and including the laminate. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional schematic view showing one embodiment of a laminate of the present invention. [Figure 2]1 is a perspective view showing one embodiment of a tube container comprising a tube container body including a laminate of the present invention and a cap. [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0022] (Laminate) As shown in FIG. 1, the laminate 10 of the present invention comprises a surface resin layer 11, a substrate 12, a gas barrier layer 13, and a heat seal layer 14, and is characterized in that the substrate 12 has a vapor-deposited film 15 on at least one surface thereof. The vapor-deposited film 15 can improve the design of a tube container produced using the laminate of the present invention, and is therefore preferably provided on the surface of the substrate on the side of the front resin layer. Since the surface resin layer 11, the substrate 12 and the heat seal layer 14 of the laminate 10 of the present invention are made of the same material, polyethylene, the laminate 10 of the present invention has high recyclability, and the tube container body comprising this laminate also has high recyclability.

[0023] In one embodiment, as shown in FIG. 1 , the laminate 10 of the present invention includes a melt-extruded polyethylene layer 16 or an adhesive layer 17 between the surface resin layer 11 and the substrate 12, between the substrate 12 and the gas barrier layer 13, and between the gas barrier layer 13 and the heat seal layer 14.

[0024] In one embodiment, the substrate 12 includes a barrier coat layer (not shown) below or above the deposited film 15.

[0025] The polyethylene content in the entire laminate of the present invention is preferably 90% by mass or more, more preferably 95% by mass or more, which can improve the recyclability of the laminate of the present invention and the tubular container comprising the laminate.

[0026] (surface resin layer and heat seal layer) The surface resin layer and the heat seal layer constituting the laminate of the present invention are made of polyethylene and both have heat sealability. The polyethylene that can be used is high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, or very low-density polyethylene. Among these, low-density polyethylene and / or linear low-density polyethylene are preferred from the viewpoint of heat-sealability.

[0027] In the present invention, the high density polyethylene has a density of 0.945 g / cm 3 The polyethylene having a density of 0.925 g / cm or more can be used. 3 More than 0.945g / cm 3 Low density polyethylene can be used, and low density polyethylene is polyethylene with a density of 0.900 g / cm 3 More than 0.925g / cm 3 Polyethylenes with a density of less than 0.900 g / cm can be used, and linear low-density polyethylenes with a density of less than 0.900 g / cm can be used. 3 More than 0.925g / cm 3 Polyethylene with a density of less than 0.900 g / cm can be used, and ultra-low density polyethylene has a density of 0.900 g / cm 3 Less than 100% polyethylene can be used.

[0028] In the present invention, polyethylene also includes copolymers of ethylene and other monomers. Examples of ethylene copolymers include copolymers of ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene. Furthermore, as long as the object of the present invention is not impaired, copolymers with vinyl acetate or acrylic esters may also be used.

[0029] The surface resin layer and the heat seal layer can contain biomass-derived polyethylene obtained by polymerizing a monomer containing biomass-derived ethylene. Such biomass-derived polyethylene is a carbon-neutral material, which can reduce the environmental impact of producing the laminate of the present invention. Since biomass-derived ethylene is used as the raw material monomer, the polymerized polyethylene is biomass-derived. Note that the raw material monomer for polyethylene does not have to contain 100% by mass of biomass-derived ethylene.

[0030] The monomers that are the raw materials for biomass-derived polyethylene may further contain ethylene and / or α-olefins derived from fossil fuels, or may further contain α-olefins derived from biomass.

[0031] The concentration of biomass-derived ethylene in the polyethylene contained in the surface resin layer and the heat seal layer (hereinafter sometimes referred to as "biomass ratio") is preferably 10% or more. "Biomass content" is a value measured by radiocarbon (C14) measurement to determine the amount of carbon derived from biomass. Carbon dioxide in the atmosphere contains a certain percentage of C14 (105.5 pMC), so it is known that the C14 content in plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the proportion of C14 in the total carbon atoms in polyethylene, the proportion of carbon derived from biomass can be calculated. In the present invention, the content of C14 in polyethylene is determined as P C14 The content of biomass-derived carbon in this case is P bio can be calculated as follows: P bio (%)=P C14 / 105.5×100

[0032] In the present invention, theoretically, if all ethylene derived from biomass is used as a raw material for polyethylene, the concentration of biomass-derived ethylene will be 100%, and the biomass content of the biomass-derived polyethylene will be 100%. Furthermore, the concentration of biomass-derived ethylene in fossil fuel-derived polyethylene produced only from fossil fuel-derived raw materials is 0%, meaning that the biomass content of fossil fuel-derived polyethylene is 0%.

[0033] Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. The plant raw material is not particularly limited, and conventionally known plants can be used. Examples of the plant raw material include corn, sugarcane, beet, and manioc.

[0034] In the present invention, biomass-derived fermented ethanol refers to ethanol produced by contacting a culture solution containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from its disruption, followed by purification. Ethanol can be purified from the culture solution by conventional methods such as distillation, membrane separation, and extraction. Examples of methods include adding benzene, cyclohexane, or the like and removing water by azeotropy or membrane separation.

[0035] A catalyst is usually used when obtaining ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited and any conventionally known catalyst can be used. From the viewpoint of the process, a fixed-bed flow reaction is advantageous because it allows easy separation of the catalyst and the product, and for example, γ-alumina is preferred.

[0036] Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. The heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, but is preferably 100°C or higher, more preferably 250°C or higher, and even more preferably 300°C or higher. There is no particular upper limit, but from the viewpoint of energy balance and equipment, it is preferably 500°C or lower, more preferably 400°C or lower.

[0037] The reaction pressure is not particularly limited, but a pressure equal to or higher than atmospheric pressure is preferred to facilitate subsequent gas-liquid separation. From an industrial perspective, a fixed-bed flow reaction is preferred because it facilitates catalyst separation, but a liquid-phase suspension bed or a fluidized bed may also be used.

[0038] In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in the ethanol supplied as a raw material. Generally, when performing a dehydration reaction, it is preferable to eliminate water in order to improve the efficiency of water removal. However, in the case of ethanol dehydration using a solid catalyst, it has been found that the absence of water tends to increase the amount of other olefins, particularly butene, produced. This is presumably because the presence of a small amount of water is insufficient to suppress ethylene dimerization after dehydration. The lower limit of the allowable water content is 0.1% or more, preferably 0.5% or more. There is no particular upper limit, but from the viewpoints of material balance and heat balance, it is preferably 50% by weight or less, more preferably 30% or less, and even more preferably 20% or less.

[0039] By carrying out the dehydration reaction of ethanol in this manner, a mixture of ethylene, water, and a small amount of unreacted ethanol is obtained, but since ethylene is in a gaseous state at room temperature and below about 5 MPa, water and ethanol can be removed from this mixture by gas-liquid separation to obtain ethylene. This method can be carried out by any known method.

[0040] The ethylene obtained by the gas-liquid separation is further distilled, and the distillation method, operation temperature, residence time, etc. are not particularly limited, except that the operation pressure at this time must be atmospheric pressure or higher.

[0041] When biomass-derived ethanol is used as the raw material, the resulting ethylene contains trace amounts of impurities introduced during the ethanol fermentation process, such as carbonyl compounds (e.g., ketones, aldehydes, and esters) and their decomposition products (carbon dioxide), as well as nitrogen-containing compounds (e.g., amines and amino acids) and their decomposition products (ammonia). Depending on the intended use of ethylene, these trace amounts of impurities may be problematic, so they may be removed by purification. The purification method is not particularly limited, and conventionally known methods can be used. Suitable purification procedures include, for example, adsorption purification. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferred, and the type of adsorbent is selected depending on the type and amount of impurities in the ethylene obtained by the dehydration reaction of biomass-derived ethanol.

[0042] A caustic water treatment may be used in combination as a method for purifying impurities in ethylene. When caustic water treatment is used, it is preferable to carry out the treatment before adsorption purification. In this case, it is necessary to carry out a water removal treatment after the caustic treatment and before adsorption purification.

[0043] The surface resin layer and heat seal layer may also contain polyethylene recycled by mechanical recycling. Here, mechanical recycling generally refers to a method in which recovered polyethylene film is crushed and washed with an alkali to remove dirt and foreign matter from the film surface, and then dried at high temperature and reduced pressure for a certain period of time to diffuse and decontaminate contaminants remaining inside the film, thereby removing dirt from the polyethylene film and returning it to polyethylene.

[0044] The surface resin layer and the heat seal layer may contain additives within the range that does not impair the properties of the present invention, such as crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0045] In one embodiment, the surface resin layer and the heat seal layer are made of a film made of polyethylene, and the film may be a stretched film or an unstretched film. From the viewpoint of heat sealability, an unstretched film is preferable.

[0046] The surface resin layer and the heat seal layer may be subjected to a surface treatment, which can improve adhesion to adjacent layers. The surface treatment method is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment, as well as chemical treatments such as oxidation treatment using chemicals. Furthermore, an anchor coating layer may be formed on the surface of the surface resin layer and the heat seal layer using a conventionally known anchor coating agent.

[0047] The thickness of the surface resin layer and the heat seal layer is preferably 30 μm or more and 150 μm or less, and more preferably 50 μm or more and 120 μm or less, and the thickness of the surface resin layer and the thickness of the heat seal layer may be the same or different. By making the thickness of the surface resin layer and the heat seal layer 30 μm or more, the heat sealability can be further improved. Furthermore, by setting the thickness of the surface resin layer and the heat seal layer to 150 μm or less, the processability of the laminate including the substrate can be improved.

[0048] In one embodiment, the surface resin layer and the heat seal layer can be produced by forming a resin composition containing at least polyethylene into a film using a T-die method, an inflation method, or the like. The surface resin layer and the substrate can be laminated via a melt-extruded polyethylene layer or an adhesive layer, which will be described later.

[0049] (base material) The substrate constituting the laminate of the present invention is made of polyethylene, and as the polyethylene, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and very low density polyethylene can be used. Among these, high density polyethylene and medium density polyethylene are preferred from the viewpoint of the strength and heat resistance of the substrate, and medium density polyethylene is more preferred from the viewpoint of the stretchability.

[0050] The substrate may contain biomass-derived polyethylene, and the concentration of biomass-derived ethylene in the polyethylene contained in the substrate (hereinafter sometimes referred to as "biomass ratio") is preferably 10% or more.

[0051] The substrate can also include recycled polyethylene through mechanical recycling.

[0052] The substrate may contain the above-mentioned additives to the extent that the properties of the present invention are not impaired.

[0053] In one embodiment, the substrate has a multi-layer structure. For example, the laminate may be configured to include a layer made of low-density polyethylene, a layer made of high-density polyethylene, and a layer made of low-density polyethylene.

[0054] In one embodiment, the substrate is made of a film made of polyethylene, and the film may be a stretched film or an unstretched film.

[0055] The substrate may be subjected to a surface treatment, which can improve adhesion to adjacent layers. The surface treatment method is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment, as well as chemical treatments such as oxidation treatment using chemicals. Alternatively, an anchor coating layer may be formed on the surface of the substrate using a conventionally known anchor coating agent.

[0056] The substrate may have a printed layer on its surface, and the image formed on the printed layer is not particularly limited, and may be a letter, a pattern, a symbol, or a combination thereof. From the viewpoint of environmental impact, it is preferable that the printing layer be formed on the substrate using ink derived from biomass. The method for forming the printed layer is not particularly limited, and examples thereof include conventionally known printing methods such as gravure printing, offset printing, flexographic printing, etc. Among these, flexographic printing is preferred from the viewpoint of environmental load.

[0057] The thickness of the substrate is preferably 10 μm or more and 50 μm or less, and more preferably 20 μm or more and 40 μm or less. By making the thickness of the substrate 10 μm or more, the strength and heat resistance can be further improved. Furthermore, by setting the thickness of the substrate to 50 μm or less, the processability of the laminate including the substrate can be improved.

[0058] In one embodiment, the substrate can be produced by forming a resin composition containing at least polyethylene into a film using a T-die method, an inflation method, or the like.

[0059] (evaporated film) The substrate has a vapor-deposited film on at least one surface, which can improve the gas barrier properties of the laminate, specifically the oxygen barrier properties and water vapor barrier properties. The vapor-deposited film is preferably provided on the surface of the substrate on the gas barrier layer side, as this can improve the design of the tubular container produced using the laminate of the present invention.

[0060] The vapor-deposited film 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 tube containers and the like produced using the laminate of the present invention and improve their design. Examples of metals that can be used to form the metal vapor deposition 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.

[0061] The surface of the deposited film is preferably subjected to the above-mentioned surface treatment, which can improve adhesion to adjacent layers.

[0062] The thickness of the vapor-deposited film is preferably 1 nm or more and 150 nm or less, and more preferably 5 nm or more and 60 nm or less. By making the thickness of the vapor-deposited film 1 nm or more, the oxygen barrier property and water vapor barrier property of the laminate can be further improved, and when it is a metal vapor-deposited film, a higher gloss can be imparted. By setting the thickness of the vapor-deposited film to 150 nm or less, it is possible to prevent cracks from occurring in the vapor-deposited film, and also to maintain the recyclability of the laminate.

[0063] The deposition film can be formed on the substrate using a conventionally known method, for example, physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

[0064] Also, for example, a composite film consisting of two or more layers of vapor-deposited films of different inorganic oxides can be formed and used by combining physical vapor deposition and chemical vapor deposition. The degree of vacuum in the deposition chamber is 10 -2 ~10 -8 After oxygen is introduced, the pressure is preferably about 10 -1 ~10 -6 A pressure of about mbar is preferred. The amount of oxygen introduced varies depending on the size of the deposition machine. An inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas for the oxygen introduced, provided that this does not cause any problems. The film transport speed can be about 10 to 800 m / min.

[0065] (barrier coat layer) In one embodiment, the substrate has a barrier coating layer below or above the vapor deposition layer, which can improve the oxygen barrier property and water vapor barrier property of the laminate. When the substrate has a vapor-deposited film, the barrier coat layer may be provided on or under the vapor-deposited film.

[0066] In one embodiment, the barrier coat layer contains a gas barrier resin such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, polyamides such as nylon 6, nylon 6,6, and polymetaxylylene adipamide (MXD6), polyester, polyurethane, and (meth)acrylic resin. Among these, polyvinyl alcohol is preferred from the viewpoint of oxygen barrier property and water vapor barrier property. Furthermore, when the vapor-deposited film is made of an inorganic oxide, the occurrence of cracks in the vapor-deposited film can be effectively prevented by including polyvinyl alcohol in the barrier coat layer.

[0067] The content of the gas barrier resin in the barrier coat layer is preferably 50% by mass or more and 95% by mass or less, and more preferably 75% by mass or more and 90% by mass or less. By making the content of the gas barrier resin in the barrier coat layer 50% by mass or more, the oxygen barrier property and water vapor barrier property of the substrate can be further improved.

[0068] The barrier coat layer may contain the above-mentioned additives to the extent that the properties of the present invention are not impaired.

[0069] 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 thickness of the barrier coat layer 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. Furthermore, by setting the thickness of the barrier coat layer to 10 μm or less, the recyclability of the laminate can be maintained.

[0070] The barrier coat layer can be formed by dissolving or dispersing the above-mentioned material in water or an appropriate solvent, applying the solution, and drying. Alternatively, the barrier coat layer can be formed by applying a commercially available barrier coating agent and drying it.

[0071] In another embodiment, the barrier coat layer is a gas barrier coating film containing at least one resin composition such as a hydrolyzate of a metal alkoxide or a hydrolyzed condensate of a metal alkoxide obtained by polycondensing 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, an organic solvent, etc. When the substrate has a vapor-deposited film made of an inorganic oxide, by providing a barrier coat layer of this type adjacent to the vapor-deposited film, it is possible to effectively prevent cracks from occurring in the vapor-deposited film.

[0072] In one embodiment, the metal alkoxide is represented by the following general formula: R1 n M(OR 2 ) m (wherein, R 1 , R 2 each represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.

[0073] As the metal atom M, for example, silicon, zirconium, titanium, aluminum, etc. can be used. Also, R 1 and R 2 Examples of the organic group represented by the formula (I) include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl group.

[0074] 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).

[0075] It is also preferable to use a silane coupling agent together with the metal alkoxide. As the silane coupling agent, known organoalkoxysilanes containing organic reactive groups can be used, but organoalkoxysilanes having epoxy groups are particularly preferred. Examples of organoalkoxysilanes having epoxy groups include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0076] Two or more of the above silane coupling agents may be used, and the silane coupling agent is preferably used in an amount of about 1 to 20 parts by mass per 100 parts by mass of the total amount of the alkoxides.

[0077] As the water-soluble polymer, polyvinyl alcohol and ethylene-vinyl alcohol copolymer are preferred, and from the viewpoints of oxygen barrier property, water vapor barrier property, water resistance and weather resistance, it is preferred to use these in combination.

[0078] The content of the water-soluble polymer in the gas barrier coating film is preferably 5 parts by mass or more and 500 parts by mass or less per 100 parts by mass of the metal alkoxide. By adjusting the content of the water-soluble polymer in the gas barrier coating film to 5 parts by mass or more per 100 parts by mass of the metal alkoxide, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. Also, by adjusting the content of the water-soluble polymer in the gas barrier coating film to 500 parts by mass or less per 100 parts by mass of the metal alkoxide, the film formability of the gas barrier coating film can be improved.

[0079] The thickness of the gas barrier coating film is preferably from 0.01 μm to 100 μm, and more preferably from 0.1 μm to 50 μm, which allows for improved oxygen barrier properties and water vapor barrier properties while maintaining recyclability. By making the thickness of the gas barrier coating film 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the laminate can be improved, and when the gas barrier coating film is provided adjacent to a vapor-deposited film made of an inorganic oxide, the occurrence of cracks in the vapor-deposited film can be prevented.

[0080] The gas barrier coating film can be formed by applying a composition containing the above-mentioned materials by a conventionally known means such as roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, or applicator coating, and then polycondensing the composition by a sol-gel method. The sol-gel catalyst is preferably an acid or an amine compound. As the amine compound, a tertiary amine that is substantially insoluble in water and soluble in an organic solvent is preferred, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, tripentylamine, etc. Among these, N,N-dimethylbenzylamine is preferred. The sol-gel catalyst is preferably used in an amount of 0.01 to 1.0 part by mass, more preferably 0.03 to 0.3 part by mass, per 100 parts by mass of the metal alkoxide. By using a sol-gel catalyst in an amount of 0.01 part by mass or more per 100 parts by mass of metal alkoxide, the catalytic effect can be improved. Furthermore, by using a sol-gel catalyst in an amount of 1.0 part by mass or less per 100 parts by mass of the metal alkoxide, the thickness of the gas barrier coating film formed can be made uniform.

[0081] The composition may further contain an acid, which is used as a catalyst in the sol-gel process, mainly for the hydrolysis of alkoxides, silane coupling agents, and the like. The acid may be a mineral acid such as sulfuric acid, hydrochloric acid, or nitric acid, or an organic acid such as acetic acid or tartaric acid. The amount of the acid used is preferably 0.001 mol or more and 0.05 mol or less based on the total molar amount of the alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent. By using an amount of acid that is 0.001 mole or more relative to the total mole amount of the alkoxide and the alkoxide portion (for example, silicate portion) of the silane coupling agent, the catalytic effect can be improved. Furthermore, by making the amount 0.05 moles or less relative to the total mole amount of the alkoxide and the alkoxide portion (for example, silicate portion) of the silane coupling agent, the thickness of the gas barrier coating film formed can be made uniform.

[0082] The composition preferably contains water in an amount of 0.1 mol or more and 100 mol or less, more preferably 0.8 mol or more and 2 mol or less, per mol of the total molar amount of the alkoxides. By adjusting the water content to 0.1 mole or more per mole of the total molar amount of alkoxides, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be improved. Furthermore, by adjusting the content of water to 100 moles or more per mole of the total molar amount of the alkoxides, the hydrolysis reaction can be carried out quickly.

[0083] The composition may also contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, or n-butanol.

[0084] An embodiment of the method for forming a gas barrier coating film will be described below. First, a composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent, etc. A polycondensation reaction gradually proceeds in the composition. The composition is then applied to a substrate by the above-mentioned conventional method and dried, which further promotes the polycondensation reaction of the alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Finally, the composition is heated at a temperature of 20 to 250°C, preferably 50 to 220°C, for 1 second to 10 minutes to form a gas barrier coating film.

[0085] The barrier coat layer may have a printed layer formed thereon, and the method for forming the printed layer is as described above.

[0086] (gas barrier layer) The gas barrier layer of the laminate of the present invention contains a gas barrier resin, which can improve the oxygen barrier property and water vapor barrier property of the laminate. The gas barrier layer may have a single layer structure or a multi-layer structure. When the gas barrier layer has a multi-layer structure, it is sufficient that at least one layer contains a gas barrier resin. In one embodiment, the multilayer gas barrier layer is composed of a first polyethylene resin layer 13A, a first adhesive layer 13B, a layer containing a gas barrier resin 13C, a second adhesive layer 13D, and a second polyethylene resin layer 13E, as shown in FIG. The adhesive layer will be described later.

[0087] Examples of gas barrier resins include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, polyamides such as nylon 6, nylon 6,6 and polymetaxylylene adipamide (MXD6), polyesters, polyurethanes, and (meth)acrylic resins.

[0088] The gas barrier layer preferably contains a compatibilizer. When a tubular container produced using the laminate of the present invention is heated and melted for recycling, the gas barrier resin contained in the gas barrier layer and the polyethylene contained in the substrate or the like are uniformly mixed together, which effectively prevents a decrease in the physical properties of the container. Furthermore, a decrease in the transparency of the container can be effectively prevented. The compatibilizer can be appropriately selected and used from conventionally known agents, but from the viewpoint of recyclability, unsaturated carboxylic acid-modified polyolefins are preferred, and among these, maleic anhydride-modified polyethylene is more preferred. When the gas barrier layer has a multi-layer structure, two or more layers may contain a compatibilizer.

[0089] The content of the compatibilizer in the entire gas barrier layer is preferably 5% by mass or more and 20% by mass or less. By setting the content of the compatibilizer in the entire gas barrier layer to 5% by mass or more, the above-mentioned deterioration in physical properties and transparency can be more effectively prevented. By setting the content of the compatibilizer in the entire gas barrier layer to 20% by mass or less, the formability of the gas barrier layer can be improved, and the laminate of the present invention can be recycled, preventing a decrease in the strength of films produced using the resulting resin.

[0090] As long as the properties of the present invention are not impaired, the gas barrier layer may contain a resin other than the gas barrier resin, and examples thereof include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, (meth)acrylic resins, cellulose resins, vinyl resins, etc. Among these, polyethylene is preferred from the viewpoints of adhesion to the substrate and the recyclability of the laminate.

[0091] The gas barrier layer may also contain the above-mentioned additives, provided that the properties of the present invention are not impaired.

[0092] In one embodiment, the gas barrier layer is made of a film, which may be a stretched film or an unstretched film. From the viewpoint of the strength of the laminate, a stretched film is preferable. The stretched film may be a uniaxially stretched film or a biaxially stretched film.

[0093] Furthermore, it is preferable that the surface of the gas barrier layer is subjected to the above-mentioned surface treatment, which can improve adhesion to adjacent layers.

[0094] When the gas barrier layer has a single layer structure, its thickness is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 20 μm or less. By making the thickness of the gas barrier layer 10 μm or more, the gas barrier properties of the laminate of the present invention can be improved. Furthermore, by setting the thickness of the gas barrier layer to 30 μm or less, the recyclability of the laminate of the present invention can be improved.

[0095] When the gas barrier layer has a multi-layer structure, the sum of the thicknesses of the layers containing the gas barrier resin is preferably 20 μm or more and 100 μm or less, and more preferably 30 μm or more and 80 μm or less. By making the sum of the thicknesses of the layers containing the gas barrier resin 20 μm or more, the gas barrier properties of the laminate of the present invention can be improved. Furthermore, by making the sum of the thicknesses of the layers containing the gas barrier resin 100 μm or less, the recyclability of the laminate of the present invention can be improved.

[0096] In one embodiment, the gas barrier layer can be produced by forming a gas barrier resin into a film using a T-die method, an inflation method, or the like. The lamination with the substrate or the like can be carried out via a melt-extruded polyethylene layer or an adhesive layer, which will be described later.

[0097] (melt-extruded polyethylene layer) In one embodiment, the laminate of the present invention may include a melt-extruded polyethylene layer between any layers, for example, between the surface resin layer and the substrate, between the substrate and the gas barrier layer, or between the gas barrier layer and the heat seal layer. The polyethylene contained in the melt-extruded polyethylene layer may be high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, or very low-density polyethylene. Among these, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene are preferred from the viewpoint of interlayer adhesion.

[0098] The melt-extruded polyethylene layer may contain biomass-derived polyethylene, and the concentration of biomass-derived ethylene in the polyethylene contained in the melt-extruded polyethylene layer (hereinafter sometimes referred to as "biomass content") is preferably 10% or more.

[0099] The melt-extruded polyethylene layer may also include polyethylene recycled by mechanical recycling.

[0100] The melt-extruded polyethylene layer may contain the above-mentioned additives to the extent that the properties of the present invention are not impaired.

[0101] The thickness of the melt-extruded polyethylene layer is preferably 5 μm or more and 30 μm or less, and more preferably 10 μm or more and 20 μm or less. By making the thickness of the melt-extruded polyethylene layer 5 μm or more, the adhesion between the layers can be further improved. Furthermore, by making the thickness of the melt-extruded polyethylene layer 30 μm or less, the production cost of the laminate of the present invention can be reduced and the productivity can be improved.

[0102] The melt-extruded polyethylene layer can be formed by melt-extruding a resin composition containing at least polyethylene onto a substrate or the like.

[0103] (adhesive layer) In one embodiment, the laminate of the present invention may have an adhesive layer between any layers, for example, between the surface resin layer and the substrate, between the substrate and the gas barrier layer, or between the gas barrier layer and the heat seal layer. The laminate of the present invention may also include an adhesive layer as a layer constituting the gas barrier layer.

[0104] The adhesive layer may be formed from a conventionally known adhesive, which may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be either a solvent-free adhesive or a solvent-based adhesive, but from the viewpoint of environmental load, a solvent-free adhesive is preferably used. Examples of solvent-free adhesives include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives, and among these, two-component curing urethane adhesives can be preferably used. Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

[0105] Furthermore, when the adhesive layer is provided adjacent to the aluminum vapor-deposited film, more specifically, when the substrate has an aluminum vapor-deposited film and the adhesive layer is provided between the aluminum vapor-deposited film and the gas barrier layer, the adhesive layer preferably consists of a cured product of a resin composition containing a polyester polyol and an isocyanate compound. When molding a laminate including a vapor-deposited film, a bending load is applied to the laminate by a molding machine or the like, which may cause cracks in the aluminum vapor-deposited film. By configuring the adhesive layer as described above, it is possible to prevent cracks from occurring in the aluminum vapor-deposited film, and even if cracks do occur, it is possible to suppress a decrease in the oxygen barrier property and water vapor barrier property (flexural load resistance).

[0106] The polyester polyol has two or more hydroxyl groups as functional groups in one molecule. The isocyanate compound has two or more isocyanate groups as functional groups in one molecule. The polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as the main skeleton.

[0107] As a specific example of a resin composition (adhesive) containing a polyester polyol and an isocyanate compound, the PASLIM series sold by DIC Corporation can be used.

[0108] The resin composition may further contain a phosphoric acid-modified compound, a plate-like inorganic compound, a coupling agent, cyclodextrin and / or a derivative thereof, and the like.

[0109] As polyester polyols having two or more hydroxyl groups in one molecule as functional groups, for example, the following [Example 1] to [Example 3] can be used. [Example 1] Polyester polyol obtained by polycondensation of ortho-oriented polycarboxylic acid or its anhydride with polyhydric alcohol [Example 2] Polyester polyol with a glycerol skeleton [Example 3] Polyester polyol with isocyanuric ring Each polyester polyol will be described below.

[0110] The polyester polyol according to the first example is a polycondensate obtained by polycondensing a polycarboxylic acid component containing at least one or more of orthophthalic acid and its anhydride, and a polyhydric alcohol component containing at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. In particular, polyester polyols in which the content of orthophthalic acid and its anhydride relative to the total polycarboxylic acid components is 70 to 100 mass % are preferred.

[0111] The polyester polyol according to the first example essentially contains orthophthalic acid and its anhydride as polycarboxylic acid components, but other polycarboxylic acid components may be copolymerized within a range that does not impair the effects of this embodiment. Specific examples include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids, and ester-forming derivatives of these dicarboxylic acids; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred. Two or more of the above other polycarboxylic acids may be used.

[0112] As a polyester polyol according to a second example, a polyester polyol having a glycerol skeleton represented by general formula (1) can be mentioned. [ka] In general formula (1), R1, R2, and R3 are each independently H (hydrogen atom) or a group represented by the following general formula (2). [ka]

[0113] In formula (2), n represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of 1,2-phenylene groups, 1,2-naphthylene groups, 2,3-naphthylene groups, 2,3-anthraquinonediyl groups, and 2,3-anthracenediyl groups, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms. However, at least one of R1, R2, and R3 represents a group represented by general formula (2).

[0114] In general formula (1), at least one of R1, R2, and R3 must be a group represented by general formula (2). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (2).

[0115] In addition, the compound may be a mixture of two or more of the following compounds: a compound in which any one of R1, R2, and R3 is a group represented by general formula (2); a compound in which any two of R1, R2, and R3 are groups represented by general formula (2); and a compound in which all of R1, R2, and R3 are groups represented by general formula (2).

[0116] X represents an optionally substituted arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group. When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. The substituent includes a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0117] In general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, or a dimethylbutylene group. Of these, a propylene group or an ethylene group is preferred, and an ethylene group is most preferred.

[0118] The polyester resin compound having a glycerol skeleton represented by general formula (1) can be synthesized by reacting glycerol, an aromatic polycarboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

[0119] Examples of aromatic polycarboxylic acids or anhydrides in which a carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracenecarboxylic acid or anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring, such as a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, or a naphthyl group.

[0120] Examples of polyhydric alcohol components include alkylene diols having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.

[0121] The polyester polyol according to the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3). [ka] In the general formula (3), R1, R2, and R3 each independently represent "-(CH2)n1-OH (wherein n1 represents an integer of 2 to 4)" or a structure of the general formula (4). [ka]

[0122] In general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms. However, at least one of R1, R2, and R3 is a group represented by general formula (4).

[0123] In the general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. Among these, n1 is preferably 2 or 3, and most preferably 2.

[0124] In the general formula (4), n2 represents an integer of 2 to 4, and n3 represents an integer of 1 to 5. X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have a substituent.

[0125] When X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. The substituent includes a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group. The substituent for X is preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimido group, a carbamoyl group, an N-ethylcarbamoyl group, or a phenyl group, and most preferably a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimido group, or a phenyl group.

[0126] In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, or a dimethylbutylene group. Of these, a propylene group or an ethylene group is preferred, and an ethylene group is most preferred.

[0127] In general formula (3), at least one of R1, R2, and R3 is a group represented by general formula (4). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (4).

[0128] In addition, the compound may be a mixture of two or more of the following compounds: a compound in which any one of R1, R2, and R3 is a group represented by general formula (4); a compound in which any two of R1, R2, and R3 are groups represented by general formula (4); and a compound in which all of R1, R2, and R3 are groups represented by general formula (4).

[0129] The polyester polyol having an isocyanuric ring represented by general formula (3) can be synthesized by reacting a triol having an isocyanuric ring, an aromatic polycarboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and a polyhydric alcohol component as essential components.

[0130] Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

[0131] Examples of aromatic polycarboxylic acids or anhydrides in which a carboxylic acid is substituted at the ortho position include orthophthalic acid or anhydride, naphthalene 2,3-dicarboxylic acid or anhydride, naphthalene 1,2-dicarboxylic acid or anhydride, anthraquinone 2,3-dicarboxylic acid or anhydride, and 2,3-anthracene carboxylic acid or anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring.

[0132] Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0133] The polyhydric alcohol component may be an alkylene diol having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, or dimethylbutanediol. Among these, polyester polyol compounds having an isocyanuric ring, which use 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid as the triol compound having an isocyanuric ring, orthophthalic anhydride as the aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted at the ortho position, and ethylene glycol as the polyhydric alcohol, are particularly preferred because of their excellent oxygen barrier properties and adhesiveness.

[0134] The isocyanuric ring is highly polar and trifunctional, and can increase the polarity of the entire system and the crosslink density. From these perspectives, it is preferable that the adhesive resin contains 5% by mass or more of the isocyanuric ring based on the total solid content of the adhesive resin.

[0135] The isocyanate compound has two or more isocyanate groups in the molecule. The isocyanate compound may be either aromatic or aliphatic, and may be either a low molecular weight compound or a high molecular weight compound. Furthermore, the isocyanate compound may be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known, conventional appropriate method. Among these, from the viewpoints of adhesiveness and retort resistance, polyisocyanate compounds having three or more isocyanate groups are preferred, and from the viewpoints of oxygen barrier property and water vapor barrier property, aromatic compounds are preferred.

[0136] Specific examples of the isocyanate compound include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, metaxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds, as well as adducts, biurets, and allophanates obtained by reacting these isocyanate compounds with low-molecular-weight active hydrogen compounds or alkylene oxide adducts thereof, or high-molecular-weight active hydrogen compounds. Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine. Examples of high molecular weight active hydrogen compounds include polymeric active hydrogen compounds of various polyester resins, polyether polyols, and polyamides.

[0137] In one embodiment, the resin composition contains a phosphoric acid-modified compound, and for example, a compound represented by the following general formula (5) or (6) can be used. [ka] In general formula (5), R1, R2, and R3 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms which has a (meth)acryloyloxy group, at least one of which is a hydrogen atom, and n is an integer of 1 to 4. [ka] In the formula, R4 and R5 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, a phenyl group which may have a substituent, and an alkyl group having 1 to 4 carbon atoms and having a (meth)acryloyloxy group, n is an integer of 1 to 4, x is an integer of 0 to 30, and y is an integer of 0 to 30, except when both x and y are 0.

[0138] More specific examples include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate, and one or more of these can be used.

[0139] The content of the phosphoric acid-modified compound in the resin composition is preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less. By adjusting the content of the phosphoric acid-modified compound to 0.005% by mass or more, the oxygen barrier property and water vapor barrier property of the laminate of the present invention can be improved. Furthermore, by setting the content of the phosphoric acid-modified compound to 10% by mass or less, the adhesiveness of the adhesive layer can be improved.

[0140] The resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound may contain a plate-like inorganic compound, which can improve the adhesiveness of the adhesive layer and the flex load resistance of the laminate of the present invention. Examples of the plate-like inorganic compounds include kaolinite-serpentine group clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talc group (pyrophyllite, talc, keroli, etc.).

[0141] Examples of coupling agents include silane-based coupling agents, titanium-based coupling agents, and aluminum-based coupling agents represented by the following general formula (7). These coupling agents may be used alone or in combination of two or more. [ka]

[0142] Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β( N-beta(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-beta(aminoethyl)γ-aminopropyltrimethoxysilane, N-beta(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene).

[0143] Examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(didodecyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctainol titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, diisostearoyl ethylene titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, and dicumyl phenyl oxyacetate titanate.

[0144] Specific examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetoacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkyl acetoacetate aluminum oxide trimer.

[0145] The resin composition may contain cyclodextrin and / or a derivative thereof, which can improve the adhesiveness of the adhesive layer and further improve the flex load resistance of the laminate of the present invention. Specifically, for example, cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, hydroxyalkylated cyclodextrin, and the like, in which the hydrogen atoms of the hydroxyl groups of the glucose units of cyclodextrin are substituted with other functional groups, can be used. Branched cyclic dextrins can also be used. Furthermore, the cyclodextrin skeleton in cyclodextrin and cyclodextrin derivatives may be any of α-cyclodextrin consisting of six glucose units, β-cyclodextrin consisting of seven glucose units, and γ-cyclodextrin consisting of eight glucose units. These compounds may be used alone or in combination of two or more. These cyclodextrins and / or their derivatives may hereinafter be collectively referred to as dextrin compounds.

[0146] From the viewpoint of compatibility and dispersibility in the resin composition, it is preferable to use a cyclodextrin derivative as the cyclodextrin compound.

[0147] Examples of alkylated cyclodextrins include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0148] Examples of acetylated cyclodextrins include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0149] Examples of hydroxyalkylated cyclodextrins include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.

[0150] The adhesive layer may contain additives such as pigments such as titanium oxide, zinc oxide and carbon black, dyes such as disperse dyes, acid dyes and cationic dyes, antioxidants, lubricants, colorants, stabilizers, wetting agents, thickeners, coagulants, gelling agents, anti-settling agents, softeners, hardeners, plasticizers, leveling agents, ultraviolet absorbers and flame retardants, as long as the additives do not impair the properties of the present invention.

[0151] The thickness of the adhesive layer is not particularly limited, and can be, for example, 1 μm or more and 5 μm or less.

[0152] (Tube container body) The tube container body of the present invention is characterized by comprising the above-described laminate. The tube container body of the present invention will be described below with reference to the drawings. Fig. 2 is a diagram showing a simplified configuration of a tube container 20, and Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. As shown in Fig. 2, the tube container body 21 is characterized by comprising a head 22 and a body 23, with the body 23 being formed from the laminate.

[0153] (head) The head portion 22 has a shoulder portion 24 connected to one end of the body portion 23 and a dispensing opening portion 25 connected to the shoulder portion 24. In one embodiment, the spout portion 25 is provided with a thread 27 for threading the cap 26 thereon.

[0154] In one embodiment, the head portion is made of a resin composition containing polyethylene, which can improve the recyclability of the tube container. The polyethylene can be high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, or very low-density polyethylene. Among these, high density polyethylene is preferred from the viewpoint of shape retention.

[0155] The resin composition may contain polyethylene derived from biomass or polyethylene recycled by chemical recycling.

[0156] The resin composition may contain the above-mentioned additives within the scope of the present invention.

[0157] The method for producing the head portion is not particularly limited, and the head portion can be produced by a conventionally known method. For example, the head portion can be produced by a compression molding method or an injection molding method, and can be joined to the body portion.

[0158] When a tube container is manufactured using the compression molding method, a body portion is attached to a male mold having a convex portion on the top, and then the male and female molds are placed opposite each other. A molten resin composition is supplied into the male and female molds, and the head portion is formed by compression molding and joined to one opening of the body portion, thereby manufacturing a tube container consisting of a head portion and a body portion. Furthermore, when a tube container is manufactured using an injection molding method, the body is attached to a male mold having a convex portion on the top, the male mold and the female mold are then placed opposite each other, a molten resin composition is supplied from a gate, and the head is formed by injection molding and joined to one opening of the body, thereby manufacturing a tube container consisting of a head and a body.

[0159] (torso) In the tube container body 21 of the present invention, the body 23 is connected to the shoulder 24 of the head 22 . The body portion 23 is formed by rolling the laminate into a cylindrical shape, overlapping the surface resin layer and the heat seal layer, and heat sealing the overlapped portion to provide a welded portion 28. The body 23 also includes a bottom seal 29 formed by heat sealing the opening of the rolled laminate.

[0160] Heat sealing can be performed by a conventionally known method such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, or flame sealing.

[0161] (Tube container) The tube container of the present invention comprises the tube container body and a cap. In one embodiment, the tube container 20 also includes a cap 26 that fits over the head 22 .

[0162] (cap) The cap is removably attached to the extraction port of the head and serves to close the extraction port. The cap is made of a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins, but polyethylene is particularly preferred from the viewpoint of recyclability. As polyethylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene can be used. Among these, high-density polyethylene is preferred from the viewpoints of shape retention and ease of opening. Biomass-derived polyethylene and mechanically recycled polyethylene can also be used. The resin composition may also contain the above-mentioned additives within the range that does not impair the characteristics of the present invention.

[0163] The cap may be a screw type having a groove on the inner surface of the cap so as to screw onto the thread 27 of the extraction port 25, as shown in Figure 2, or it may be a stopper type that fits onto the extraction port 27 by tapping it. [Example]

[0164] 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.

[0165] Example 1 (Preparation of laminate) Linear low-density polyethylene 1 (ExxonMobil, Exceed 2018HA, density 0.918 g / cm 3) and high-density polyethylene (ExxonMobil, HTA108, density 0.961 g / cm 3 ) and linear low-density polyethylene 2 (Dow Chemical, Dowlex 2098G, density 0.926 g / cm 3 ) were co-extruded by an inflation method to obtain a substrate film. The substrate film obtained as described above had a three-layer structure with a total thickness of 40 μm, comprising a 10 μm-thick layer composed of linear low-density polyethylene 1, a 20 μm-thick layer composed of high-density polyethylene, and a 10 μm-thick layer composed of linear low-density polyethylene 2 (linear low-density polyethylene layer / high-density polyethylene layer / linear low-density polyethylene layer). A 20 nm thick aluminum vapor deposition film was formed by PVD on the surface of the layer made of linear low density polyethylene 1 of the substrate film to obtain a substrate.

[0166] A urethane adhesive (RU004 / H1, manufactured by Rock Paint) was applied to the vapor-deposited surface of the substrate and dried to form a 3 μm thick adhesive layer, and a 100 μm thick unstretched linear low-density polyethylene film (manufactured by Tamapoly Co., Ltd., product name: UB-3) was laminated on top of this adhesive layer as a surface resin layer.

[0167] Linear low-density polyethylene (Dow Chemical, Dowlex 2045G, density 0.920 g / cm 3 ), adhesive resin (Mitsui Chemicals, Admer NF557), ethylene-vinyl alcohol copolymer (Kuraray, Eval H171B, density 1.17 g / cm3, ethylene content 38 mol%), adhesive resin (Mitsui Chemicals, Admer NF557), linear low-density polyethylene (Dow Chemical, Dowlex 2045G, density 0.920 g / cm 3) were co-extruded by an inflation method to form a five-layer gas barrier layer. The gas barrier layer obtained as described above had a five-layer structure with a total thickness of 60 μm, including a 17.5 μm-thick layer composed of linear low-density polyethylene, a 5 μm-thick layer composed of adhesive resin, a 15 μm-thick layer composed of ethylene-vinyl alcohol copolymer, a 5 μm-thick layer composed of adhesive resin, and a 17.5 μm-thick layer composed of linear low-density polyethylene (linear low-density polyethylene layer / adhesive resin layer / ethylene-vinyl alcohol copolymer layer / adhesive resin layer / linear low-density polyethylene layer).

[0168] On the non-evaporated film of the substrate, low-density polyethylene (Novatec LC600A, manufactured by Nippon Polyethylene, density 0.918 g / cm 3 ) was melt-extruded to form a melt-extruded polyethylene layer having a thickness of 20 μm, and one layer of linear low-density polyethylene provided in the gas barrier layer was laminated via this melt-extruded polyethylene layer.

[0169] On the other layer of linear low-density polyethylene provided in the gas barrier layer, low-density polyethylene (Novatec LC600A, manufactured by Nippon Polyethylene, density 0.918 g / cm 3 ) was melt-extruded to form a melt-extruded polyethylene layer having a thickness of 20 μm, and a 100 μm thick unstretched linear low-density polyethylene film (manufactured by Tamapoly Co., Ltd., trade name: UB-3) was laminated as a heat seal layer through this melt-extruded polyethylene layer to produce a laminate of the present invention. The polyethylene content in this laminate was 92%.

[0170] Example 2 Linear low-density polyethylene (Dow Chemical, Dowlex 2045G, density 0.920 g / cm 3 ) and a compatibilizer (Dow Chemical, maleic anhydride modified polyethylene, Retain 3000, density 0.870 g / cm 3) were blended in a ratio of linear low-density polyethylene:compatibilizer=93% by mass:7% by mass to prepare a blend resin.

[0171] The blend resin prepared above, an adhesive resin (Mitsui Chemicals, Admer NF557), an ethylene-vinyl alcohol copolymer (Kuraray, EVAL H171B, density 1.17 g / cm3, ethylene content 38 mol%), an adhesive resin (Mitsui Chemicals, Admer NF557), and the blend resin were co-extruded into a five-layer film by inflation method to obtain a gas barrier layer. The gas barrier layer obtained as described above had a five-layer structure with a total thickness of 60 μm, including a 17.5 μm thick layer composed of the blend resin, a 5 μm thick layer composed of the adhesive resin, a 15 μm thick layer composed of the ethylene-vinyl alcohol copolymer, a 5 μm thick layer composed of the adhesive resin, and a 17.5 μm thick layer composed of the blend resin (blend resin layer / adhesive resin layer / ethylene-vinyl alcohol copolymer layer / adhesive resin layer / blend resin layer).

[0172] A laminate of the present invention was produced in the same manner as in Example 1, except that the gas barrier layer was changed to one produced as described above. The polyethylene content in this laminate was 91%.

[0173] Comparative Example 1 A laminate was produced in the same manner as in Example 1, except that the base film was a 12 μm-thick biaxially oriented polyethylene terephthalate (Ester Film E5100, manufactured by Toyobo Co., Ltd.) The polyethylene content in this laminate was 87%.

[0174] (Production of tube containers) The laminate obtained as described above was cut into a 120 mm wide slit using a bobbin cutter, and the two widthwise ends were overlapped so that the overlap width was approximately 1.5 mm. The overlapped ends were then heat-sealed to obtain a cylindrical raw roll. The obtained raw roll was cut into a length of 122 mm to produce a cylindrical body portion that would become the body of a tube container.

[0175] The cylindrical body was attached to a mandrel for forming a tube container, and a head consisting of a truncated cone-shaped shoulder and a cylindrical extraction port connected to it was attached to one end of the cylindrical body using high-density polyethylene (Novatec HJ360, manufactured by Nippon Polyethylene, density 0.951 g / cm 3 ) was injection molded to produce a tube container as shown in Figure 3. The spout at the top of the obtained tube container body had an outer diameter of 13 mm and a height of 1.5 mm, and a thread was provided on the side of the spout. The outer diameter of the shoulder was 38 mm.

[0176] Next, the high density polyethylene was injected into a cap-forming mold and molded to prepare a cap, thereby obtaining the tube container of the present invention.

[0177] <<Recyclability evaluation>> The recyclability of the laminates for packaging materials obtained in the above Examples and Comparative Examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. (Evaluation criteria) Good: The content of the same polyolefin in the laminate for packaging material was 90% by mass or more. Bad: The content of the same polyolefin in the laminate for packaging material was less than 90% by mass.

[0178] <<Shoulder adhesive strength>> Test pieces were obtained by cutting a strip 15 mm wide from the joining point between the body and shoulder toward the bottom. The test piece was pulled at a test speed of 300 mm / min using a tensile tester (Orientec Co., Ltd., RTC-1310A) to measure the peel strength when the body was peeled from the shoulder. The measurement results are summarized in Table 1.

[0179] <<Side seam strength>> The specimens were cut into 15 mm strips perpendicular to the side seam (overlapping area) of the body, and the strength at break was measured by pulling them at a test speed of 300 mm / min using a tensile tester. The measurement results are summarized in Table 1.

[0180] <<Leakage evaluation>> A cap was screwed onto the extraction opening of the tube container body, and then 120 g of commercially available toothpaste was poured into the opening of the cylindrical body, which was then heat-sealed. The tightening torque when closing the cap was set to 4.7 kg·cm. The container was left at room temperature for two weeks, and visually inspected every day to ensure there was no leakage of the contents. The evaluation criteria for leakage were as follows: (Evaluation criteria) 〇: No leakage of contents was observed even after 2 weeks. ×: Leakage of contents was observed within 2 weeks

[0181] [Table 1] [Explanation of symbols]

[0182] 10: laminate, 11: surface resin layer, 12: substrate, 13: gas barrier layer, 13A: first polyethylene resin layer, 13B: first adhesive layer, 13C: layer containing gas barrier resin, 13D: second adhesive layer, 13E: second polyethylene resin layer, 14: heat seal layer, 15: vapor deposition film, 20: tube container, 21: tube container body, 22: head, 23: body, 24: shoulder, 25: extraction spout, 26: cap, 27: thread, 28: welded portion, 29: bottom seal portion

Claims

1. a surface resin layer, a substrate, a gas barrier layer, and a heat seal layer in this order; the surface resin layer, the base material, and the heat seal layer are made of the same material, the surface resin layer has heat-sealability, the same material is polyethylene; the surface resin layer and the base material are laminated via an adhesive layer, the gas barrier layer comprises a first polyethylene resin layer, a first adhesive layer, a layer containing a gas barrier resin, a second adhesive layer, and a second polyethylene resin layer; A laminate, characterized in that the polyethylene content in the entire laminate is 90 mass % or more.

2. 2. The laminate according to claim 1, further comprising a melt-extruded polyethylene layer or an adhesive layer at least one of between the surface resin layer and the substrate, between the substrate and the gas barrier layer, and between the gas barrier layer and the heat seal layer.

3. 3. The laminate according to claim 1, wherein the polyethylene constituting the surface resin layer and the heat seal layer is low-density polyethylene and / or linear low-density polyethylene.

4. The laminate according to any one of claims 1 to 3, wherein the layer containing the gas barrier resin has a thickness of 20 µm or more and 100 µm or less.

5. The laminate according to any one of claims 1 to 4, wherein the surface resin layer and the heat seal layer have a thickness of 30 µm or more and 150 µm or less.

6. The laminate according to any one of claims 1 to 5, wherein the substrate has a thickness of 10 µm or more and 50 µm or less.

7. The laminate according to any one of claims 1 to 6, which is used for a tube container.

8. It has a head and a body, The head portion has a shoulder portion connected to one end of the body portion and a sampling port portion connected to the shoulder portion, A tube container, characterized in that the body portion is formed from the laminate according to any one of claims 1 to 7.

9. The tube container according to claim 8, wherein the head portion is made of a resin composition containing polyethylene.

10. The tube container according to claim 8 or 9, further comprising a cap made of a resin composition containing polyethylene.

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