Containers and preforms thereof

Abstract

To provide a container having excellent recyclability.SOLUTION: A container has a support, a protective layer provided on at least one side of the support, and a barrier layer provided between the support and the protective layer. The support contains thermoplastic resin. The barrier layer contains a carboxylated resin, a polyvalent metal compound and a reaction product.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a container and a preform thereof. [Background technology]

[0002] In recent years, used plastic containers have been recycled with the aim of reducing the environmental load, such as reducing carbon dioxide emissions. Recycling must be done with the same type of material, so for example, when recycling used PET bottles, the collected PET bottles must be separated into the label, cap, and bottle body. In addition, when the bottle body has a multi-layer structure, for example, when it has a support and a coating layer provided on the surface of the support, it must be separated into the support and the coating layer.

[0003] Patent Document 1 discloses a plastic bottle having a polyvinyl alcohol coating as a barrier layer on the outer surface of a support, and a polyvinyl butyral coating as a protective layer on the polyvinyl alcohol coating. Since polyvinyl alcohol is water-soluble, the barrier layer between the support and the protective layer of the plastic bottle disclosed in Patent Document 1 can be dissolved during recycling, and as a result, the support, the barrier layer, and the protective layer can be separated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6037879 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in containers having a polyvinyl alcohol coating as a barrier layer, the support and the protective layer may not be completely separated when recycling the container, leaving room for improvement in terms of recyclability.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a container having excellent recyclability and a preform for said container. [Means for solving the problem]

[0007] The present invention provides a container comprising a support, a protective layer provided on at least one surface side of the support, and a barrier layer provided between the support and the protective layer, The support comprises a thermoplastic resin, The barrier layer is a container containing a carboxyl group-containing resin, a polyvalent metal compound, and a reaction product.

[0008] In the container according to the present invention, the carboxyl group-containing resin may be polyacrylic acid.

[0009] In the container according to the present invention, the polyvalent metal compound may be at least one selected from the group including chlorides, nitrates, sulfates, phosphates, phosphites, and hypophosphites.

[0010] In the container according to the present invention, the polyvalent metal of the polyvalent metal compound may be at least one selected from the group including magnesium, calcium, and zinc.

[0011] In the container according to the present invention, the barrier layer of the preform may have a thickness of 0.1 μm or more and 200 μm or less.

[0012] In the container according to the present invention, the thermoplastic resin may be at least one selected from the group including polyesters and polyolefins.

[0013] The present invention relates to a preform of the container. Effect of the Invention

[0014] According to the present invention, it is possible to provide a container having excellent recyclability and a preform for the container. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic half-sectional view showing one embodiment of a bottle, which is an example of a container of the present invention. [Diagram 2] FIG. 1 is a schematic half-sectional view showing one embodiment of a bottle, which is an example of a container of the present invention. [Diagram 3] FIG. 1 is a schematic half-sectional view showing one embodiment of a bottle, which is an example of a container of the present invention. [Figure 4] FIG. 1 is a schematic half-sectional view showing one embodiment of a cup, which is an example of a container of the present invention. [Diagram 5] FIG. 1 is a schematic half sectional view showing an embodiment of a preform, which is an example of a preform of the present invention. [Figure 6] FIG. 1 is a schematic half sectional view showing an embodiment of a preform, which is an example of a preform of the present invention. [Figure 7] FIG. 1 is a schematic half sectional view showing an embodiment of a preform, which is an example of a preform of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Container> The container of the present invention comprises a support, a protective layer provided on at least one surface side of the support, and a barrier layer provided between the support and the protective layer. In this specification, the term "container" refers to a molded body that contains an article. Examples of the container include molded bodies such as compression molded bodies, injection molded bodies, blow molded bodies, and thermoformed bodies. Specific examples of the container include bottles, vials, cups, trays, and packs.

[0017] Each of the components that the container of the present invention may have will be described below.

[0018] (Support) In the container of the present invention, the support is capable of maintaining the shape of the container and contains a thermoplastic resin. Examples of the thermoplastic resin contained in the support include polyolefins such as polyethylene and polypropylene, polyesters such as polycarbonate, polyvinyl chloride, and polyethylene terephthalate, polyamides such as nylon 6 and nylon 6,6, and mixtures thereof. From the viewpoint of moldability, the thermoplastic resin is preferably at least one selected from the group including polyesters and polyolefins. The thermoplastic resin is preferably a polyester from the viewpoints of gas barrier properties, strength, and adhesion to the barrier layer, whereas the thermoplastic resin is preferably a polyolefin from the viewpoint of flexibility of the container.

[0019] In this specification, the term "polyester" refers to a polymer that is polymerized through ester bonds. Such polyesters are usually obtained by polycondensation of a dicarboxylic acid compound and a diol compound. Examples of dicarboxylic acid compounds include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, pimelic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, adamantanedicarboxylic acid, norbornenedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodiumsulfoisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, 9,9'-bis(4-carboxyphenyl)fluorene acid, and ester derivatives thereof. Examples of the diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalenedimethanol, decahydronaphthalenediethanol, norbornanedimethanol, norbornanediethanol, tricyclodecanedimethanol, tricyclodecaneethanol, tetracyclododecanedimethanol, tetracyclododecanediethanol, decalindimethanol, decalindiethanol, and 5-methylol-5-ethyl -2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane, cyclohexanediol, bicyclohexyl-4,4'-diol, 2,2-bis(4-hydroxycyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamantanediol, paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane, pentaerythritol, and bis-β-hydroxyethyl terephthalate (BHET). The polyester is preferably polyethylene terephthalate or a modified polyethylene terephthalate obtained by polymerizing a raw material monomer of polyethylene terephthalate and a copolymerizable monomer.

[0020] From the viewpoint of recyclability, the content of one type of thermoplastic resin in the support is preferably 90% by mass or more, and more preferably 97% by mass or more.

[0021] The support may contain additives within the range that does not impair the characteristics of the present invention. Examples of additives include oxygen absorbers, plasticizers, ultraviolet stabilizers, antioxidants, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, friction reducers, slip agents, mold release agents, antioxidants, and ion exchange agents. These additives can be used alone or in combination of two or more.

[0022] The support may have a single layer structure or a multi-layer structure of two or more layers. When the support has a multi-layer structure, each layer may have the same composition or different compositions as long as the characteristics of the present invention are not impaired.

[0023] The cross-sectional thickness of the support is preferably 0.01 mm or more and 0.35 mm or less, and more preferably 0.05 mm or more and 0.25 mm or less. The cross-sectional thickness of the support can be measured, for example, at the body of the container. The cross-sectional thickness of the support means the point where the cross-sectional thickness is the thinnest.

[0024] The support is preferably subjected to a surface treatment. Examples of the surface treatment include corona treatment, low-temperature plasma treatment, and flame treatment. By performing such a surface treatment, the wettability of the support surface is improved, and the adhesion between the support and a layer in contact with the support can be improved.

[0025] (Barrier layer) In the container according to the present invention, the barrier layer contains a reaction product of a carboxyl group-containing resin and a polyvalent metal compound. Such a reaction product is a carboxyl group-containing resin crosslinked by a polyvalent metal (ion). By providing such a barrier layer, the polyester container according to the present invention can improve recyclability while maintaining barrier properties. The reason for this will be explained below.

[0026] In recycling used containers, the containers are first crushed into flakes, and then washed with liquids such as water and an alkaline solution. If a water-soluble or alkaline-soluble layer is present between the support and the protective layer, this layer dissolves in the washing process, and the protective layer can be peeled off from the support to separate the support. Therefore, such containers have excellent recyclability. Polyvinyl alcohol is generally a water-soluble resin, but in order to separate the support and the protective layer in the washing step of recycling, a layer consisting of only polyvinyl alcohol has insufficient solubility. The reaction product of a carboxyl group-containing resin and a polyvalent metal compound, i.e., a carboxyl group-containing resin crosslinked by a polyvalent metal (ion), has high solubility due to the presence of polyvalent metal ions. As a result, the container according to the present invention, which is provided with a barrier layer containing the reaction product of a carboxyl group-containing resin and a polyvalent metal compound, has excellent recyclability. In addition, the reaction product of the carboxyl group-containing resin crosslinked by the polyvalent metal ion has a high cohesive force and is therefore effective in blocking oxygen and water vapor, so that the barrier layer containing the reaction product of the carboxyl group-containing resin and the polyvalent metal compound has high gas barrier properties. As described above, by forming the barrier layer as a layer containing a reaction product of a carboxy group-containing resin and a polyvalent metal compound, it is possible to obtain a container that has gas barrier properties and excellent recyclability.

[0027] The carboxyl group-containing resin and polyvalent metal compound used in the barrier layer will be described below.

[0028] The carboxyl group-containing resin may be an existing carboxyl group-containing resin. The carboxyl group-containing resin is a general term for resins that contain a carboxyl group in the polymer structure. Examples of the carboxyl group-containing resin include homopolymers of carboxyl group-containing unsaturated monomers, copolymers of carboxyl group-containing unsaturated monomers, copolymers of carboxyl group-containing unsaturated monomers and other polymerizable monomers, and polysaccharides containing a carboxyl group in the molecule (also called "acidic polysaccharides"). These carboxyl group-containing resins may be used alone or in combination of two or more. The carboxy group includes not only a free carboxy group but also an acid anhydride group (specifically, a dicarboxylic acid anhydride group). The acid anhydride group may be partially ring-opened to become a carboxy group. In the carboxy group-containing resin, a part of the carboxy group may be neutralized with an alkali.

[0029] The carboxyl group-containing unsaturated monomer is preferably an α,β-monoethylenically unsaturated carboxylic acid. Therefore, the carboxyl group-containing resin includes a homopolymer of an α,β-monoethylenically unsaturated carboxylic acid, a copolymer of two or more kinds of α,β-monoethylenically unsaturated carboxylic acids, and a copolymer of an α,β-monoethylenically unsaturated carboxylic acid and another polymerizable monomer. The other polymerizable monomer may be an ethylenically unsaturated monomer.

[0030] Examples of α,β-monoethylenically unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, etc., unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, etc., unsaturated dicarboxylic anhydrides such as maleic anhydride, itaconic anhydride, etc. These acids can be used alone or in combination of two or more. The α,β-monoethylenically unsaturated carboxylic acid is preferably selected from one or more of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and more preferably selected from one or more of acrylic acid, methacrylic acid, and maleic acid.

[0031] Examples of other polymerizable monomers copolymerizable with α,β-monoethylenically unsaturated carboxylic acids, particularly ethylenically unsaturated monomers, include ethylene; α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene; saturated carboxylic acid vinyl esters such as vinyl acetate; acrylic acid alkyl esters such as methyl acrylate and ethyl acrylate; methacrylic acid alkyl esters such as methyl methacrylate and ethyl methacrylate; chlorine-containing vinyl monomers such as vinyl chloride and vinylidene chloride; fluorine-containing vinyl monomers such as vinyl fluoride and vinylidene fluoride; unsaturated nitriles such as acrylonitrile and methacrylonitrile; aromatic vinyl monomers such as styrene and α-methylstyrene; itaconic acid alkyl esters, etc. These monomers can be used alone or in combination of two or more.

[0032] Examples of the carboxyl group-containing polysaccharides include acidic polysaccharides having a carboxyl group in the molecule, such as alginic acid, carboxymethylcellulose, and pectin. These acidic polysaccharides can be used alone or in combination of two or more. The acidic polysaccharides can be used in combination with a (co)polymer of an α,β-monoethylenically unsaturated carboxylic acid.

[0033] When the carboxyl group-containing resin used in the present invention is a copolymer of an α,β-monoethylenically unsaturated carboxylic acid and another ethylenically unsaturated monomer, the composition of the copolymer is such that the composition of the α,β-monoethylenically unsaturated carboxylic acid monomer is preferably 60 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more.

[0034] The carboxyl group-containing resin is preferably a homopolymer or copolymer obtained by polymerization of only α,β-monoethylenically unsaturated carboxylic acid. When the polycarboxylic acid polymer is a (co)polymer consisting of only α,β-monoethylenically unsaturated carboxylic acid, the carboxyl group-containing resin is preferably a homopolymer, copolymer, or mixture of two or more thereof obtained from a carboxylic acid selected from one or more of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and more preferably a homopolymer, copolymer, or mixture of two or more thereof obtained from a carboxylic acid selected from one or more of acrylic acid, methacrylic acid, and maleic acid.

[0035] The carboxyl group-containing resin is preferably one or more selected from polyacrylic acid, polymethacrylic acid, and maleic acid polymers. The carboxyl group-containing resin is preferably polyacrylic acid, which is relatively easy to obtain and has good recyclability and gas barrier properties.

[0036] The number average molecular weight of the carboxyl group-containing resin is preferably in the range of 2,000 to 10,000,000, more preferably in the range of 5,000 to 1,000,000, and even more preferably in the range of 10,000 to 500,000.

[0037] The polyvalent metal compound refers to a simple polyvalent metal atom having a metal ion with a valence of two or more, and a compound thereof.

[0038] Examples of polyvalent metals include beryllium, magnesium, calcium, barium, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, etc. These polyvalent metals can be used alone or in combination of two or more. The polyvalent metal is preferably at least one selected from the group including magnesium, calcium, and zinc. By selecting at least one of these polyvalent metals, the barrier layer can be made transparent, so that the bottle can be given various designs and can be made into a bottle with rich design. From the viewpoint of gas barrier properties, the polyvalent metal is particularly preferably magnesium.

[0039] Examples of polyvalent metal compounds include oxides, hydroxides, organic acid salts, inorganic acid salts of polyvalent metals, and other ammonium complexes of polyvalent metals, secondary to quaternary amine complexes of polyvalent metals, and organic acid salts and inorganic acid salts of these complexes. Examples of organic acid salts include acetates, oxalates, citrates, lactates, stearates, monoethylenically unsaturated carboxylates, etc. Examples of inorganic acid salts include chlorides, nitrates, carbonates, sulfates, phosphates, phosphites, hypophosphites, etc. Other examples include alkyl alkoxides of polyvalent metals. These compounds can be used alone or in combination of two or more. From the viewpoint of gas barrier properties, the polyvalent metal compound is preferably at least one selected from the group including chlorides, nitrates, sulfates, phosphates, phosphites, and hypophosphites, and more preferably a chloride, a nitrate, or a mixture thereof.

[0040] In the barrier layer, the amount of the polyvalent metal compound is preferably 0.05 to 5.00 chemical equivalents, more preferably 0.1 to 3.00 chemical equivalents, even more preferably 0.20 to 2.00 chemical equivalents, and still more preferably 0.30 to 1.50 chemical equivalents, relative to all carboxy groups in the carboxy group-containing resin. The term "all carboxy groups" is used to mean carboxy groups of the carboxy group-containing resin that were not involved in the reaction, and carboxy groups that become polyvalent metal salts of polycarboxylic acids in the reaction product obtained by reacting the carboxy group-containing resin with a polyvalent metal compound. The chemical equivalent can be determined, for example, as follows. An example will be described in which the carboxyl group-containing resin is acrylic acid and the polyvalent metal compound is magnesium chloride. The molecular weight of the monomer unit of polyacrylic acid is 72, and since one monomer molecule has one carboxyl group, when the mass of polyacrylic acid is 100g, the amount of carboxyl groups in 100g of polyacrylic acid is 1.39mol. At this time, 1 equivalent to 100g of polyacrylic acid is the amount of base that neutralizes 1.39mol. Therefore, when 0.2 equivalents of magnesium chloride are mixed with 100g of polyacrylic acid, it is sufficient to add magnesium chloride enough to neutralize 0.278mol of carboxyl groups. Since the valence of magnesium is divalent and the molecular weight of magnesium oxide is 95, 0.2 equivalents of magnesium chloride to 100g of polyacrylic acid is 13.2g (0.139mol).

[0041] The barrier layer may contain components other than the reaction products as long as the characteristics of the present invention are not impaired. Examples of such components include unreacted carboxyl group-containing resin, unreacted polyvalent metal compound, by-products produced by the reaction of the carboxyl group-containing resin with the polyvalent metal compound, and other resin components.

[0042] The barrier layer may contain additives within the range that does not impair the characteristics of the present invention. Examples of additives include oxygen absorbers, plasticizers, ultraviolet stabilizers, antioxidants, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducing agents, slip agents, mold release agents, antioxidants, and ion exchange agents. These additives can be used alone or in combination of two or more.

[0043] The barrier layer may be a single layer or a multi-layer consisting of two or more layers. When the barrier layer is a multi-layer, each layer may have the same composition or different compositions.

[0044] The thickness of the barrier layer is preferably 0.1 μm or more and 200 μm or less, and more preferably 1 μm or more and 50 μm or less. The thickness of the barrier layer can be measured, for example, at the body of the container. The thickness of the barrier layer means the part where the thickness is the thinnest. When the barrier layer has multiple layers, the thickness of the barrier layer is the sum of the thicknesses of all the layers.

[0045] The barrier layer may be colored in red, blue, yellow, green, brown, brownish-brown, orange, black, white, or the like, and may be transparent or opaque. The colored barrier layer can absorb visible light entering the container from the outside, such as sunlight, and can suppress changes in taste and color of the contents of the container. In particular, when the contents are beer, a container with such a barrier layer is less likely to transmit visible light with a wavelength of 400 nm or more and 500 nm or less through the container, so that the problem of the bitter components in the beer being decomposed by sunlight to produce 3-methyl-2-butene-1-thiol, which is a sunlight odor component, can be suppressed. Since the barrier layer can effectively absorb visible light with a wavelength of 400 nm or more and 500 nm or less, it is preferably colored in brown or orange. For example, a coloring agent can be used to color the barrier layer.

[0046] (protective layer) In the container according to the present invention, the protective layer is for protecting the barrier layer. By providing the protective layer to the container, deterioration of the barrier function due to physical factors such as damage or peeling of the barrier layer, or chemical factors such as moisture absorption or dissolution, can be suppressed during the manufacture and use of the container.

[0047] In one embodiment, the protective layer contains a thermoplastic resin. Examples of the thermoplastic resin contained in the protective layer include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, acrylic resins, polyacetal, polyester, polyurethane, and polyvinyl acetal. These thermoplastic resins can be used alone or in combination of two or more.

[0048] In one embodiment, the thermoplastic resin contained in the protective layer is preferably polyvinyl acetal from the viewpoint of adhesion to the barrier layer. The polyvinyl acetal is particularly preferably polybutyl butyral. Polyvinyl butyral is a polymer having a structural unit having a vinyl butyral group in the molecule. Among them, a polymer having at least a structural unit having a vinyl butyral group and a structural unit having a hydroxyl group, which is represented by the following chemical formula (I), is preferable.

[0049] [ka] (In chemical formula (I), "l" is the mole % of the constituent units having a vinyl butyral group, and is expressed as the mole % of the total of the constituent units derived from butyralized vinyl alcohol. "m" represents the mole % of the constituent units derived from vinyl alcohol, and "n" represents the mole % of the constituent units derived from vinyl acetate. Both l and m are numbers greater than 0, and n may be 0.)

[0050] Polyvinyl butyral is obtained by acetalizing polyvinyl alcohol (also called "PVA") with butyraldehyde. When acetalizing PVA, it is difficult to completely acetalize the PVA, and some hydroxyl groups remain irreversibly. Therefore, polyvinyl butyral resin contains hydroxyl groups. In addition, PVA is usually produced by saponifying polyvinyl acetate, but since a small amount of acetyl group often remains during the saponification process of polyvinyl alcohol production, polyvinyl butyral generally has acetyl group and hydroxy group remaining partially and irreversibly. Therefore, polyvinyl butyral usually contains acetyl group, and a polymer having a structural unit having a vinyl butyral group, a structural unit having an acetyl group, and a structural unit having a hydroxy group is preferably used.

[0051] From the viewpoint of durability of the protective layer, the polyvinyl butyral preferably has a butyralization degree of 50 mol % or more and 90 mol % or less, more preferably 60 mol % or more and 85 mol % or less, and even more preferably 65 mol % or more and 75 mol % or less. Here, the degree of butyralization is a molar fraction obtained by dividing the amount of ethylene groups to which butyral groups are bonded by the total amount of ethylene groups in the main chain, and corresponds to the mole % (1) of the structural unit having a vinyl butyral group in chemical formula (I).

[0052] From the viewpoint of durability of the protective layer, the polyvinyl butyral preferably contains a structural unit having a hydroxyl group, i.e., a structural unit (m) derived from vinyl alcohol, of 10 mol % or more and 40 mol % or less, more preferably 14.9 mol % or more and 34 mol % or less, and even more preferably 24.5 mol % or more and 31 mol % or less.

[0053] In polyvinyl butyral, the content of structural units having an acetyl group, i.e., structural units (n) derived from vinyl acetate, is preferably 10 mol % or less, more preferably 0.1 mol % or more and 6 mol % or less, and even more preferably 0.5 mol % or more and 4 mol % or less.

[0054] Polyvinyl butyral may further contain structural units obtained by reacting vinyl alcohol with an aldehyde other than butyraldehyde to form acetalized units, the content of such structural units being preferably 10 mol % or less. In the chemical formula (I), the sum of l, m, and n is preferably 100 mol %.

[0055] The number average molecular weight of polyvinyl butyral is preferably 15,000 to 90,000, more preferably 20,000 to 70,000, and even more preferably 25,000 to 65,000, from the viewpoint of durability of the protective layer.

[0056] When the polyvinyl butyral is dissolved in 5% by mass aqueous ethanol to give a concentration of 10% by mass, the viscosity of the resulting aqueous solution is preferably 3 mPa·s or more and 300 mPa·s or less, more preferably 10 mPa·s or more and 280 mPa·s or less, and even more preferably 20 mPa·s or more and 260 mPa·s or less. The viscosity of the aqueous solution can be measured at a temperature of 20° C. using a falling ball viscometer in accordance with JIS Z 8803:2011.

[0057] The glass transition temperature (Tg) of polyvinyl butyral is preferably 50° C. or more and 100° C. or less, more preferably 60° C. or more and 80° C. or less, from the viewpoint of durability of the protective layer. The glass transition temperature (Tg) can be obtained by measuring the change in heat quantity by DSC (differential scanning calorimetry) (DSC method).

[0058] In another embodiment, the thermoplastic resin contained in the protective layer is preferably polyurethane from the viewpoint of heat resistance and water resistance. Polyurethane can be obtained by a known method, and the manufacturing method is not limited. Polyurethane is, for example, a reaction product generated by reacting an organic polyol with an organic polyisocyanate (urethanization reaction).

[0059] The organic polyol may be a compound having a functional group number in one molecule of preferably 2 to 6, more preferably 2 to 4, and a number average molecular weight of preferably 500 to 100,000, more preferably 1,000 to 30,000. More specifically, polyester polyol, polyether polyol, polyether ester polyol, polyester amide polyol, acrylic polyol, polycarbonate polyol, polyhydroxyl alkane, polyurethane polyol, castor oil, or a mixture thereof (hereinafter, these may be referred to as organic polyol (1)). Among these, the organic polyol is preferably polyurethane polyol. In the present specification, the number average molecular weight can be measured by gel permeation chromatography (GPC). In GPC measurement, the number average molecular weight of a polymer is generally measured in terms of standard polystyrene.

[0060] Examples of polyester polyols include polyester polyols obtained by reacting dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, and sebacic acid, or dialkyl esters thereof, or mixtures thereof, with glycols such as ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, and polytetramethylene ether glycol, or mixtures thereof. Examples of polyester polyols include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone).

[0061] Examples of polyether polyols include polyether polyols obtained by polymerizing an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran using a low molecular weight polyol such as water, ethylene glycol, propylene glycol, trimethylolpropane, or glycerin as an initiator.

[0062] Examples of polyether ester polyols include polyether ester polyols obtained by reacting a dibasic acid such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, or sebacic acid, or a dialkyl ester thereof, or a mixture thereof, with the above-mentioned polyether polyol.

[0063] Examples of polyesteramide polyols include polyesteramide polyols obtained by mixing an aliphatic diamine having an amino group, such as ethylenediamine, propylenediamine, or hexamethylenediamine, with the raw materials in the esterification reaction.

[0064] Examples of acrylic polyols include acrylic polyols obtained by copolymerizing hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, etc., which contain one or more hydroxyl groups in one molecule, or corresponding methacrylic acid derivatives thereof, with, for example, acrylic acid, methacrylic acid, or an ester thereof.

[0065] Examples of polycarbonate polyols include polycarbonate polyols obtained by reacting one or more glycols selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1,8-nonanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, and hydrogenated bisphenol A with dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, or the like.

[0066] The polyhydroxyalkane is butadiene, or butadiene and acrylamide, etc. Examples of the liquid rubber include those obtained by copolymerization.

[0067] The polyurethane polyol is a polyol having a urethane bond in one molecule, and examples thereof include polyurethane polyols obtained by reacting a polyol such as a polyether polyol, a polyester polyol, or a polyether ester polyol having a number average molecular weight of 200 to 20,000 with an organic polyisocyanate so that the ratio of isocyanate groups to hydroxyl groups (NCO / OH) is less than 1, preferably 0.9 or less. In the polyurethane polyol, the polyol used is preferably a polyester polyol having a number average molecular weight of 200 to 20,000. Such a polyurethane polyol may be referred to as a polyester polyurethane polyol.

[0068] As the organic polyol, one having a carboxy group in its molecule (inside the molecule or at the molecular end) (hereinafter referred to as organic polyol (2)) can be used. The organic polyol (2) is preferably obtained by reacting the above organic polyol (1) with a polybasic acid or an anhydride thereof. The organic polyol (1) used in this case is one containing two or more hydroxyl groups at the molecular end and having a number average molecular weight of preferably 1,000 to 100,000, more preferably 3,000 to 15,000.

[0069] Examples of polybasic acids or their anhydrides include aromatic polybasic acids such as phthalic acid, trimellitic acid, pyromellitic acid, etc., and their anhydrides, and particularly preferred are their anhydrides, such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. Furthermore, ethylene glycol bisanhydrotrimellitate, glycerol trisanhydrotrimellitate, ethylene glycol bisanhydropyromellitate, glycerol trisanhydropyromellitate, which are derived from these anhydrides, abietic acid, which is a rosin component, C10H16 diene compounds, and derivatives obtained by addition reaction of maleic anhydride with the mixtures thereof, etc., can be used.

[0070] The synthesis of the organic polyol (2) is carried out by adding a polybasic acid or an anhydride thereof, preferably a polybasic acid anhydride, under heating after the synthesis of the organic polyol (1). During the synthesis of the organic polyol, it is possible to obtain an organic polyol containing a carboxyl group inside or at the molecular end in a single step from a polybasic carboxylic acid and a polyhydric alcohol.

[0071] The organic polyisocyanate has two or more isocyanate groups in one molecule. Examples of the organic polyisocyanate include aliphatic diisocyanates such as linear alkylene diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate, and branched alkylene diisocyanates such as 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate. Isocyanates; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, and 1,3-bis(isocyanatomethyl)cyclohexane; m-phenylene Aromatic diisocyanates such as 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, ω,ω'-diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, 4,4'-toluidine diisocyanate, dianisidine diisocyanate, 4,4'-diphenylether diisocyanate, etc. aromatic aliphatic diisocyanates such as 1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or mixtures thereof; organic triisocyanates such as triphenylmethane-4,4',4"-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, and polyisocyanate monomers such as organic tetraisocyanates such as 4,4'-diphenyldimethylmethane-2,2'-5,5'-tetraisocyanate. In addition to the above monomers, examples of organic polyisocyanates include dimers, trimers, biurets, and allophanates derived from the above polyisocyanate monomers; polyisocyanates having a 2,4,6-oxadiazinetrione ring obtained from carbon dioxide gas and the above polyisocyanate monomers; ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, and the like. Examples of the polyisocyanate monomer include adducts of low-molecular-weight polyols having a molecular weight of less than 200, such as ethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, and sorbitol, and the above-mentioned polyisocyanate monomers; and adducts of polyester polyols, polyether ester polyols, polyester amide polyols, polycaprolactone polyols, polyvalerolactone polyols, acrylic polyols, polycarbonate polyols, polyhydroxy alkanes, castor oil, polyurethane polyols, and the like having a molecular weight of 200 or more and 20,000 or less, and the above-mentioned polyisocyanate monomers. The organic polyisocyanates mentioned above may be used alone or as a mixture of two or more kinds. In one embodiment, the organic polyisocyanate is preferably an adduct as described above, more preferably an adduct of a monomeric polyisocyanate with a polyurethane polyol.

[0072] In the urethanization reaction, at least one selected from the group consisting of a silane coupling agent, a phosphorus oxyacid, and a derivative of a phosphorus oxyacid may be further used.

[0073] As the silane coupling agent, for example, those represented by the following chemical formula (II) or (III) can be used. R-Si≡(X) 3 (II) R-Si≡(R')(X) 2 (III) In formulas (II) and (III), R represents an organic group having a vinyl group, an epoxy group, an amino group, an imino group or a mercapto group, R' represents a lower alkyl group, and X represents a methoxy group, an ethoxy group or a chlorine atom. Examples of the silane coupling agent include chlorosilanes such as vinyltrichlorosilane, aminosilanes such as N-(dimethoxymethylsilylpropyl)ethylenediamine and N-(triethoxysilylpropyl)ethylenediamine, epoxysilanes such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane, vinylsilanes such as vinyltriethoxysilane, etc. The amount of the silane coupling agent added is preferably 0.1% by mass or more and 5% by mass or less based on the polyurethane obtained.

[0074] Among the phosphorus oxygen acids or derivatives thereof, the phosphorus oxygen acid may be any one having at least one free oxygen acid, and examples thereof include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid, and condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid. Examples of the derivatives of phosphorus oxygen acids include those obtained by partially esterifying the above phosphorus oxygen acids with alcohols while leaving at least one free oxygen acid. Examples of these alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerin, and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. One or more types of phosphorus oxygen acids or derivatives thereof may be used. The amount of phosphorus oxygen acid or derivatives thereof added is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, and even more preferably 0.1% by mass or more and 1% by mass or less, based on the polyurethane obtained.

[0075] In one embodiment, the polyurethane is a polyurethane polyol, preferably a reaction product of a polyurethane polyol having a carboxy group in the molecule and an organic polyisocyanate. The organic polyisocyanate is preferably an adduct of a polyisocyanate monomer and a polyurethane polyol. By making the polyurethane into such a reaction product, the heat resistance of the container can be further improved.

[0076] In one embodiment, the polyurethane may be a reaction product of a polyester polyol and two or more organic polyisocyanates, at least one of which may be a linear alkylene diisocyanate. The linear alkylene diisocyanate may be hexamethylene diisocyanate.

[0077] The protective layer may contain additives within the range that does not impair the characteristics of the present invention. Examples of additives include oxygen absorbers, plasticizers, ultraviolet stabilizers, antioxidants, coloring inhibitors, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducing agents, slip agents, mold release agents, antioxidants, ion exchange agents, and colorants. These additives can be used alone or in combination of two or more.

[0078] The protective layer may be a single layer or a multi-layer consisting of two or more layers. When the barrier layer is a multi-layer, each layer may have the same composition or different compositions.

[0079] The thickness of the protective layer is preferably 0.5 μm or more and 1000 μm or less, and more preferably 0.7 μm or more and 500 μm or less, which can further improve the deterioration resistance of the barrier layer. The thickness of the protective layer can be measured, for example, at the body of the container, and means the thinnest point. When the protective layer has multiple layers, the thickness of the protective layer is the sum of the thicknesses of all the layers.

[0080] The protective layer may be colored in red, blue, yellow, green, brown, reddish brown, orange, black, white, or the like, and may be transparent or opaque. By coloring the protective layer, it is possible to absorb light such as sunlight that enters the container from the outside, as in the case of coloring the barrier layer, and to suppress changes in taste and color of the contents of the container. Since it can effectively absorb visible light with a wavelength of 400 nm or more and 500 nm or less, the protective layer is preferably colored in reddish brown or orange, or the like. For example, a colorant can be used to color the protective layer.

[0081] (evaporated film) The container of the present invention may have a vapor-deposited film in order to further improve the gas barrier properties.

[0082] Examples of the vapor-deposited film include vapor-deposited films composed of metals such as aluminum, inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide, organic silicon compounds such as hexamethyldisiloxane, and hard carbon films such as DLC (Diamond Like Carbon) films. In addition, the hard carbon film made of DLC is also called i-carbon film or hydrogenated amorphous carbon film (aC:H), and is a hard carbon film. 3 It is an amorphous carbon film that is mainly composed of bonds.

[0083] The thickness of the deposited film is not particularly limited, and can be, for example, 1 nm or more and 150 nm or less. The thickness of the deposited film can be measured, for example, at the body of the container, and refers to the location where the thickness is the thinnest.

[0084] The deposition film can be formed by a conventional 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.

[0085] Hereinafter, an embodiment of the container structure according to the present invention will be described by taking a bottle and a cup as examples.

[0086] 1 to 3 are schematic half-sectional views showing one embodiment of a bottle, which is an example of a container of the present invention. As shown in Figs. 1 to 3, a bottle 10 has a mouth 11, a neck 12 provided below the mouth 11, a shoulder 13 provided below the neck 12, a body 14 provided below the shoulder 13, and a bottom 15 provided below the body 14.

[0087] The mouth portion 11 includes a threaded portion 16 to which a cap (not shown) is screwed, a cap 17 provided below the threaded portion 16, and a support ring 18 provided below the cap 17. The shape of the mouth portion 11 may be any conventional shape. In this specification, "upper" and "lower" refer to the upper and lower sides, respectively, of the bottle 10 or cup 30 when held upright (FIGS. 1 to 4).

[0088] The neck 12 is located between the support ring 18 and the shoulder 13, and has a generally cylindrical shape with a generally uniform diameter. The shoulder 13 is located between the neck 12 and the body 14, and has a shape whose diameter gradually increases from the neck 12 side toward the body 14 side.

[0089] The body 14 has a cylindrical shape with a generally uniform diameter as a whole. However, this is not limited thereto, and the body 14 may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Alternatively, the body 14 may have a cylindrical shape with a non-uniform horizontal cross section from top to bottom. Furthermore, the body 14 has a generally flat surface without any irregularities, but this is not limited thereto. For example, the body 14 may have irregularities such as panels or grooves.

[0090] The bottom 15 has a recess 19 located in the center and a grounding portion 20 provided around the recess 19. The shape of the bottom 15 is not particularly limited, and may be any conventionally known bottom shape (for example, a petaloid bottom shape or a rounded bottom shape).

[0091] 1 to 3, the bottle 10 includes a support 21 and a protective layer 23 provided on one surface of the support 21. In addition, the bottle 10 includes a barrier layer 22 between the support 21 and the protective layer 23, as shown in FIGS.

[0092] In one embodiment, as shown in Fig. 1, the mouth 11 of the bottle 10 is formed by a support 21, and the neck 12, the shoulder 13, the body 14, and the bottom 15 are formed by the support 21, a barrier layer 22, and a protective layer 23. As shown in Fig. 1, in the neck 12, the shoulder 13, the body 14, and the bottom 15, the barrier layer 22 is provided on the entire outer area of ​​the support 21 so as to surround the support 21. As shown in Fig. 1, the protective layer 23 is provided on the entire outer area of ​​the barrier layer 22 so as to surround the barrier layer 22.

[0093] In one embodiment, as shown in Fig. 2, the mouth 11 and neck 12 of the bottle 10 are formed by a support 21, and the shoulder 13, body 14 and bottom 15 are formed by the support 21, a barrier layer 22 and a protective layer 23. As shown in Fig. 2, in the shoulder 13, body 14 and bottom 15, the barrier layer 22 is provided on the entire outer area of ​​the support 21 so as to surround the support 21. As shown in Fig. 2, the protective layer 23 is provided on the entire outer area of ​​the barrier layer 22 so as to surround the barrier layer 22.

[0094] In one embodiment, bottle 10 may not have barrier layer 22 and protective layer 23 in a range of 1 mm to 10 mm downward from the lower end of support ring 18. When filling bottle 10 with contents, the portion below the lower end of support ring 18 (neck portion 12, etc.) is grasped and transported, and if barrier layer 22 and protective layer 23 are provided in this portion, there is a risk of poor grasping. A bottle that does not have barrier layer 22 and protective layer 23 provided in a range of 1 mm to 10 mm downward from the lower end of support ring 18 can prevent such poor grasping. This range is preferably 2 mm to 5 mm. It should be noted that this range is the distance from the lower end of the support ring 18 in a direction perpendicular to a plane when the bottle 10 is standing on the plane.

[0095] In one embodiment, the barrier layer 22 and the protective layer 23 may be provided on the entirety or a portion of one or more regions selected from the neck portion 12 , the shoulder portion 13 , the body portion 14 and the bottom portion 15 . In one embodiment, the bottle 10 is preferably provided with a barrier layer 22 and a protective layer 23 over the entire exterior area of ​​the body 14. More preferably, the bottle 10 is provided with a barrier layer 22 and a protective layer 23 over the entire exterior area of ​​the shoulder 13 and body 14.

[0096] 3, when the bottom end of the mouth portion 11 is defined as "0L" and the ground portion 20 is defined as "1L", the bottle 10 has the barrier layer 22 and the protective layer 23 provided over the entire outer area of ​​at least 0.4 L to 0.6 L. With this configuration, when the barrier layer 22 is a barrier layer, the gas barrier property can be efficiently improved. The bottle 10 is preferably provided with a barrier layer 22 and a protective layer 23 over the entire outer area of ​​at least 0.1 L to 0.8 L, and more preferably provided with a barrier layer 22 and a protective layer 23 over the entire outer area of ​​at least 0.05 L to 0.95 L.

[0097] A barrier layer 22 and a protective layer 23 may be provided on the inside of the bottle 10 (not shown). The bottle 10 may be provided with a vapor-deposited film on at least one selected from the group consisting of the inside and the outside of the bottle 10 (not shown).

[0098] 4 is a schematic half-sectional view showing a cup, which is one embodiment of the container of the present invention. As shown in FIG. 4, the cup 30 has a mouth 31, a body 32 provided below the mouth 31, and a bottom 33 provided below the body 32.

[0099] The mouth portion 31 has a flange shape, but the shape of the mouth portion 31 is not particularly limited and may be any conventionally known shape.

[0100] The body 32 has a cylindrical shape with a generally uniform diameter overall, but is not limited thereto, and may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Alternatively, the body 32 may have a cylindrical shape with a non-uniform horizontal cross section from top to bottom. In addition, the body 32 in FIG. 4 has a generally flat surface without any irregularities, but is not limited thereto. For example, the body 32 may have irregularities such as panels or grooves.

[0101] The bottom 33 has a recess 34 located in the center and a grounding portion 35 provided around the recess 34. The shape of the bottom 33 is not particularly limited, and may have any conventionally known bottom shape (for example, a rounded bottom shape).

[0102] As shown in Fig. 4, the cup 30 has a mouth 31 formed of a support 36, and a body 32 and a bottom 33 formed of the support 36, a barrier layer 37, and a protective layer 38. As shown in Fig. 4, in the body 32 and the bottom 33, the barrier layer 37 is provided on the entire outer area of ​​the support 36 so as to surround the support 36. In one embodiment, the barrier layer 37 and the protective layer 38 may be provided on the entirety or a portion of one or more regions selected from the mouth portion 31 , the body portion 32 and the bottom portion 33 .

[0103] A barrier layer 37 and a protective layer 38 may be provided on the inside of the cup 30 (not shown). The cup 30 may include a deposited film (not shown) on at least one selected from the group including the inside and outside of the cup.

[0104] When an item is placed in the cup 30, the cup 30 is sealed using a lid material having gas barrier properties (not shown), thereby making the cup have gas barrier properties.

[0105] In one embodiment, the container of the present invention may be a blow molded product of a preform. As the preform, the preform of the present invention described below may be used. When the container of the present invention is a bottle, a preform may be used as the preform.

[0106] When the bottle is a blow molded product of a preform, the volume increase rate of the bottle relative to the preform is preferably 2 or more and 45 or less, more preferably 5 or more and 40 or less, and further preferably 8 or more and 35 or less. The volume increase rate of the bottle relative to the preform means the volume increase rate of the blow molded part. For example, the volume of the preform other than the mouth part is V1 The volume of the bottle after blow molding other than the mouth is V 2 The volume increase rate when V 2 / V 1 " means.

[0107] In the bottle, the oxygen permeability is preferably 0.100 cc / day·bottle·0.21 atm or less, more preferably 0.070 cc / day·bottle·0.21 atm or less, even more preferably 0.050 cc / day·bottle·0.21 atm or less, and even more preferably 0.040 cc / day·bottle·0.21 atm or less. In this specification, oxygen permeability is a value measured in accordance with JIS K 7126-2:2006 using an oxygen permeability measuring device (e.g., product name: OX-TRAN 2 / 20 manufactured by MOCON) under conditions of 23°C and humidity of 40% RH, and is the value measured over the entire bottle with the mouth sealed with a jig and divided by the surface area of ​​the entire bottle excluding the mouth.

[0108] The cross-sectional thickness of the container of the present invention is preferably 0.1 mm or more and 0.4 mm or less, and more preferably 0.15 mm or more and 0.3 mm or less. The cross-sectional thickness of the container can be measured, for example, at a body portion of the container having at least the support, the barrier layer, and the protective layer. The cross-sectional thickness of the container means the point where the cross-sectional thickness is the thinnest.

[0109] The container of the present invention has a volume / mass of preferably 5 mL / g or more and 50 mL / g or less, and more preferably 8 mL / g or more and 45 mL / g or less. By setting the volume / mass of the container to 5 mL / g or more, the weight of the container can be reduced. Furthermore, by setting the volume / mass of the container to 50 mL / g or less, the strength of the container can be improved.

[0110] The container of the present invention may have a full capacity of, for example, 100 mL or more and 2000 mL or less. The full capacity of the container is preferably 280 mL or more and 750 mL or less. Furthermore, the container of the present invention may be a large one having a full capacity of, for example, 10 L or more and 60 L or less.

[0111] In the container of the present invention, the transmittance of visible light having a wavelength of 400 nm or more and 500 nm or less is preferably 20% or less. This makes it possible to suppress changes in the taste and color of the contents. In particular, when the contents is beer, the problem of odor caused by sunlight can be suppressed. The transmittance is more preferably 15% or less, even more preferably 5% or less, and even more preferably 1% or less. Such a transmittance can be adjusted by appropriately coloring at least one layer selected from the group including the protective layer and the barrier layer. The transmittance of visible light having a wavelength of 400 nm or more and 500 nm or less can be obtained by measuring the light transmittance of visible light wavelengths at 0.5 nm intervals using a spectrophotometer. As the spectrophotometer, an ultraviolet-visible spectrophotometer manufactured by Shimadzu Corporation can be used. The transmittance of the container is measured, for example, in the body of the container having at least the support, the barrier layer, and the protective layer.

[0112] The container of the present invention may be printed on its surface. The image formed by printing is not particularly limited, and examples thereof include patterns and letters. From the viewpoint of not being affected by the color tone of the container, the printing is preferably applied to the outer surface of the container. Printing can be carried out by a known method, such as an inkjet method, a gravure printing method, an offset printing method, a flexographic printing method, a thermal transfer method, a silk screen method, a pad method, a hot stamp method, or a cold stamp method. Furthermore, a printed container can be obtained by blow molding a preform on which a print has been applied.

[0113] <Container manufacturing method> The method for producing a container of the present invention will be described below with reference to a bottle as an example.

[0114] In one embodiment, the bottle 10 shown in FIG. 1 can be manufactured by the following procedure. First, a support 21 having a mouth portion 11, a neck portion 12, a shoulder portion 13, a body portion 14, and a bottom portion 15 is prepared by a conventionally known method. Next, a coating liquid for the barrier layer containing the material for forming the barrier layer 22 and a solvent is prepared. Next, the coating liquid for the barrier layer is applied to the neck portion 12, the shoulder portion 13, the body portion 14 and the bottom portion 15 of the support 21 to form a coating film. The coated film is then dried to remove the solvent, thereby forming the barrier layer 22. Next, a coating liquid for the protective layer containing polyurethane and a solvent is prepared. Next, the protective layer coating liquid is applied to the surface of the barrier layer 22 to form a coating film. Next, the coating film is dried to remove the solvent, thereby forming the protective layer 23, and the bottle 10 shown in FIG. 1 can be produced. The bottle 10 shown in Figs. 2 and 3 can be manufactured by appropriately selecting the locations to which the barrier layer coating fluid and the protective layer coating fluid are applied.

[0115] In one embodiment, the bottle 10 shown in Figures 1 to 3 can be produced by blow molding a preform 40 shown in Figures 5 to 7, which will be described later. The blow molding can be carried out by a conventionally known method.

[0116] The solvent used in the coating liquid for the barrier layer is one that can dissolve or emulsify and disperse the material that constitutes the barrier layer. Examples of the solvent include water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, and n-pentyl alcohol; and polar organic solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more. The solvent is preferably water, methyl alcohol, or a mixture thereof, since the material constituting the barrier layer can be uniformly dissolved in the solvent.

[0117] In the coating solution for the barrier layer, the total concentration of the materials constituting the barrier layer is preferably 3% by mass or more and 15% by mass or less, and more preferably 5% by mass or more and 12% by mass or less, which allows the formation of a barrier layer with a uniform thickness.

[0118] The coating liquid for the barrier layer can be applied by a conventionally known method, for example, a method of applying the coating liquid by a brush, a method of immersing a container in the coating liquid for the barrier layer, a method of spraying the coating liquid for the barrier layer on the surface of a container, etc.

[0119] The drying temperature of the coating film formed from the coating liquid for the barrier layer is a temperature at which the solvent can be removed, and is preferably 20° C. or higher and 80° C. or lower, more preferably 40° C. or higher and 70° C. or lower, and even more preferably 50° C. or higher and 70° C. or lower.

[0120] The solvent used in the protective layer coating liquid is not particularly limited as long as it can dissolve and emulsify and disperse the protective layer forming material, and examples of the solvent that can be used include water, acetone, ethyl methyl ketone, methyl isobutyl ketone, ethyl acetate, methanol, ethanol, isopropanol, etc. When polyol, polyisocyanate, and polyurethane are used as the protective layer forming material, the solvent is preferably acetone, ethyl methyl ketone, methyl isobutyl ketone, ethyl acetate, etc.

[0121] The coating liquid for the protective layer can be applied by a conventionally known method, such as a method of applying the coating liquid by a brush, a method of immersing a container in the coating liquid for the protective layer, or a method of spraying the coating liquid for the protective layer on the surface of a container.

[0122] The drying temperature of the coating film formed from the protective layer coating liquid is a temperature at which the solvent can be removed, and is preferably 20°C or higher and 80°C or lower, more preferably 40°C or higher and 70°C or lower, and even more preferably 50°C or higher and 70°C or lower.

[0123] The method for manufacturing a container of the present invention may include a step of printing images such as patterns and letters on the surface of the container. Printing can be performed by a known method. Examples of printing methods include inkjet printing, gravure printing, offset printing, flexographic printing, thermal transfer printing, silk screen printing, pad printing, hot stamping, and cold stamping. For example, when printing is performed by the inkjet method, a UV-curable ink is applied to the container, and then irradiated with UV light to harden the ink. Printing may also be performed using a thermal transfer sheet.

[0124] <Preform> As described above, the container of the present invention can be produced by forming a barrier layer and a protective layer on the surface of a support obtained by various methods such as compression molding, injection molding, blow molding, and thermoforming. In particular, when the support is obtained by blow molding, a barrier layer and a protective layer can be formed on the surface of the support of a preform before blow molding, and the preform can be blow molded to produce a container. In this specification, the preform is a molded body before blow molding the container of the present invention, and is used to produce the container of the present invention. The shape of the preform can be appropriately selected depending on the shape of the container after blow molding. The preform of the present invention comprises a support, a protective layer provided on at least one side of the support, and a barrier layer provided between the support and the protective layer.

[0125] Each of the components of the preform of the present invention will be described below.

[0126] (Support) In the preform of the present invention, the material constituting the support may be the same as the material constituting the support of the container of the present invention. By using such a material for the support, the container of the present invention can be obtained, and a preform with excellent blow moldability can be obtained.

[0127] The support may have a single layer structure or a multi-layer structure having two or more layers. When the support has a multi-layer structure, each layer may have the same composition or different compositions.

[0128] The cross-sectional thickness of the support is preferably 1.3 mm or more and 4.3 mm or less, and more preferably 1.9 mm or more and 2.9 mm or less. The cross-sectional thickness of the support can be measured, for example, at the body portion of the preform, and refers to the location where the cross-sectional thickness is the thinnest.

[0129] The support of the preform is preferably subjected to a surface treatment. Examples of the surface treatment include corona treatment, low-temperature plasma treatment, and flame treatment. By performing such a surface treatment, the wettability of the support surface is improved, and the adhesion between the support and the layer in contact with the support can be improved.

[0130] (Barrier layer) In the preform of the present invention, the material constituting the barrier layer can be the same as the material constituting the barrier layer in the container of the present invention. By using such a material for the barrier layer, the container of the present invention can be obtained, and a preform with excellent blow moldability can be obtained.

[0131] The barrier layer is preferably a layer having light-shielding properties, glossiness, color, gas barrier properties, etc., depending on the application of the container produced from the preform. The barrier layer is particularly preferably a barrier layer having gas barrier properties.

[0132] The barrier layer may be a single layer or a multi-layer consisting of two or more layers. When the barrier layer is a multi-layer, each layer may have the same composition or different compositions.

[0133] The thickness of the barrier layer is preferably 2 μm or more and 1000 μm or less, and more preferably 20 μm or more and 500 μm or less. The thickness of the barrier layer can be measured, for example, at the body of the preform. The thickness of the barrier layer means the part where the thickness is the thinnest. When the barrier layer has multiple layers, the thickness of the barrier layer is the sum of the thicknesses of all the layers.

[0134] The barrier layer or protective layer may be colored in a color such as red, blue, yellow, green, brown, reddish brown, orange, black, or white, and may be transparent or opaque. By forming such a barrier layer, a container having a colored barrier layer can be manufactured. The barrier layer can be colored, for example, by using a coloring agent.

[0135] (protective layer) In the preform of the present invention, the material constituting the protective layer can be the same as the material constituting the protective layer in the container of the present invention. By using such a material for the protective layer, the container of the present invention can be obtained, and a preform with excellent blow moldability can be obtained.

[0136] The protective layer may be a single layer or a multi-layer consisting of two or more layers. When the protective layer is a multi-layer, each layer may have the same composition or different compositions.

[0137] The thickness of the protective layer is preferably 0.5 μm or more and 1000 μm or less, and more preferably 0.7 μm or more and 500 μm or less. The thickness of the protective layer can be measured, for example, at the body of the preform. The thickness of the protective layer means the part where the thickness is the thinnest. When the protective layer has multiple layers, the thickness of the protective layer is the sum of the thicknesses of all the layers.

[0138] The protective layer may be colored in a color such as red, blue, yellow, green, brown, reddish brown, orange, black, or white, and may be transparent or opaque. By forming such a protective layer, a container having a colored protective layer can be manufactured. For example, a coloring agent can be used to color the protective layer.

[0139] Hereinafter, one embodiment of the structure of the preform according to the present invention will be described by taking a preform as an example.

[0140] 5 to 7 are schematic half-sectional views showing one embodiment of a preform according to the present invention. As shown in Figs. 5 to 7, the preform 40 includes a mouth portion 41, a body portion 42 connected to the mouth portion 41, and a bottom portion 43 connected to the body portion 42. Of these, the mouth portion 41 corresponds to the mouth portion 11 of the bottle 10 described below, and has substantially the same shape as the mouth portion 11. The body portion 42 corresponds to the neck portion 12, shoulder portion 13, and body portion 14 of the bottle 10, and has a substantially cylindrical shape. The bottom portion 43 corresponds to the bottom portion 15 of the bottle 10, and has a substantially hemispherical shape.

[0141] Mouth 41 is provided with a threaded portion 44 corresponding to threaded portion 16 of bottle 10 (described below) to which a cap (not shown) is screwed, a cap 45 provided below threaded portion 44 and corresponding to cap 17 of bottle 10, and a support ring 46 provided below cap 45 and corresponding to support ring 18 of bottle 10. Mouth 41 may have a conventionally known shape.

[0142] 5 to 7, the preform 40 includes a support 47 and a protective layer 49 provided on one surface of the support 47. In addition, the preform 40 includes a barrier layer 48 between the support 47 and the protective layer 49, as shown in FIGS.

[0143] In one embodiment, as shown in Fig. 5, the preform 40 has a mouth portion 41 formed of a support 47, and a body portion 42 and a bottom portion 43 formed of the support 47, a barrier layer 48, and a protective layer 49. As shown in Fig. 5, the barrier layer 48 is provided on the entire outer area of ​​the support 47 so as to surround the support 47. As shown in Fig. 5, the protective layer 49 is provided on the entire outer area of ​​the barrier layer 48 so as to surround the barrier layer 48.

[0144] In one embodiment, as shown in Fig. 6, the mouth portion 41 and a part of the body portion 42 of the preform 40 are formed by the support 47, and the remaining portion of the body portion 42 and the bottom portion 43 are formed by the support 47, a barrier layer 48, and a protective layer 49. As shown in Fig. 6, the barrier layer 48 is provided on the entire outer area of ​​the support 47 so as to surround the support 47. As shown in Fig. 6, the protective layer 49 is provided on the entire outer area of ​​the barrier layer 48 so as to surround the barrier layer 48. In the above, "a part of the body 42" refers to the part corresponding to the neck 12 of the bottle 10 shown in FIG. 2, and "the remaining part of the body 42" refers to the parts corresponding to the shoulder 13, the body 14, and the bottom 15 of the bottle 10 shown in FIG. 2.

[0145] In one embodiment, the preform 40 may not have the barrier layer 48 and the protective layer 49 in a range of 1 mm to 10 mm below the lower end of the support ring 46. This makes it possible to manufacture a bottle that is less likely to be gripped when being transported when filling the bottle with contents. The range is preferably 2 mm to 5 mm.

[0146] In one embodiment, the barrier layer 48 and the protective layer 49 may be provided over the entire or partial area in the vertical direction of at least one portion selected from the group including the body portion 42 and the bottom portion 43 . 7, when the lower end of the mouth portion 41 is defined as "0L" and the lower end of the bottom portion 43 is defined as "1L", the preform 40 has a barrier layer 48 and a protective layer 49 provided over the entire outer area of ​​at least 0.4L to 0.6L. By configuring the preform in this way, when the barrier layer 48 is a barrier layer, a container with efficiently improved gas barrier properties can be obtained. The preform 40 is preferably provided with a barrier layer 48 and a protective layer 49 over the entire outer area of ​​at least 0.2L to 0.7L, and more preferably provided with a barrier layer 48 and a protective layer 49 over the entire outer area of ​​at least 0.1L to 0.9L.

[0147] A barrier layer 48 and a protective layer 49 may be provided on the inside of the preform 40 (not shown).

[0148] The cross-sectional thickness of the preform is preferably 1.4 mm or more and 4.5 mm or less, and more preferably 2 mm or more and 3 mm or less. The cross-sectional thickness of the preform can be measured, for example, at a body portion of the preform having at least the support, the barrier layer, and the protective layer. The cross-sectional thickness of the preform means the point where the cross-sectional thickness is the thinnest.

[0149] In the preform of the present invention, the transmittance of visible light having a wavelength of 400 nm or more and 500 nm or less is preferably 20% or less. This makes it possible to produce a container in which changes in taste and color of the contents of the container are suppressed. The transmittance is more preferably 15% or less, even more preferably 5% or less, and even more preferably 1% or less. Such a transmittance can be adjusted by appropriately coloring at least one layer selected from the group including the protective layer and the barrier layer. The transmittance of visible light having a wavelength of 400 nm or more and 500 nm or less can be obtained by measuring the light transmittance of visible light wavelengths at 0.5 nm intervals using a spectrophotometer. As the spectrophotometer, an ultraviolet-visible spectrophotometer manufactured by Shimadzu Corporation can be used. The transmittance of the preform is measured, for example, in the body portion of the preform having at least the support, the barrier layer, and the protective layer.

[0150] The surface of the preform of the present invention may be printed. The image formed by printing is not particularly limited, and examples thereof include patterns and letters. From the viewpoint of not being affected by the color tone of the preform, the printing is preferably performed on the outer surface of the preform. Printing can be carried out by a known method, such as an inkjet method, a gravure printing method, an offset printing method, a flexographic printing method, a thermal transfer method, a silk screen method, a pad method, a hot stamp method, and a cold stamp method.

[0151] <Method of manufacturing preform> The method for producing a preform according to the present invention will be described below with reference to an example of a preform.

[0152] In one embodiment, the preform 40 depicted in FIG. 5 can be manufactured by the following procedure. First, the material constituting the support is injection molded using a conventionally known device to produce support 47 having mouth portion 41, body portion 42, and bottom portion 43. Next, a coating liquid for the barrier layer containing the material for forming the barrier layer 48 and a solvent is prepared. Next, the coating liquid for the barrier layer is applied to the body portion 42 and the bottom portion 43 of the support 47 to form a coating film. The coated film is then dried to remove the solvent, thereby forming a barrier layer 48. Next, a coating liquid for the protective layer containing polyurethane and a solvent is prepared. Next, the protective layer coating liquid is applied to the surface of the barrier layer 48 to form a coating film. Next, the coating film is dried to remove the solvent, thereby forming a protective layer 49, and the preform 40 shown in FIG. 5 can be manufactured. The preform 40 shown in Figs. 6 and 7 can be manufactured by appropriately selecting the locations to which the barrier layer coating fluid and the protective layer coating fluid are applied.

[0153] The coating fluid for the barrier layer and the coating fluid for the protective layer in the method for producing a preform can be the same as the coating fluid for the barrier layer and the coating fluid for the protective layer in the method for producing a container.

[0154] The coating liquid for the barrier layer and the coating liquid for the protective layer can be applied by a conventionally known method, such as a method of applying the coating liquid with a brush, a method of immersing a preformed body in the coating liquid for the barrier layer, or a method of spraying the coating liquid for the barrier layer on the surface of the preformed body.

[0155] The method for producing a preform of the present invention may include a step of printing images such as patterns and characters on the surface of the preform. Printing can be performed by a known method. Examples of printing methods include inkjet printing, gravure printing, offset printing, flexographic printing, thermal transfer printing, silk screen printing, pad printing, hot stamping, and cold stamping. For example, when printing is performed by the inkjet method, printing can be performed by applying a UV-curable ink to the preform, irradiating it with UV light, and curing it. Also, printing may be performed using a thermal transfer sheet. EXAMPLES

[0156] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0157] [Example 1] Pellets of polyethylene terephthalate (PET) were prepared. The PET was melted and injected into an injection molding machine to produce a preform support having a mouth, a body, and a bottom. The mouth of the support has a screw portion, a cap, and a support ring in this order from above the mouth.

[0158] Separately, 6.8 g of polyacrylic acid (manufactured by Nippon Shokubai Co., Ltd., product name: AS-58, number average molecular weight: 106,000) and 3.2 g of magnesium chloride were dissolved in 190 g of methyl alcohol to prepare a coating liquid for the barrier layer. This coating liquid for the barrier layer was applied to the body and bottom of the support to form a coating film. This coating film was dried at 50°C for 10 minutes to obtain a preform having a barrier layer. The amount of magnesium chloride was 0.71 chemical equivalents relative to all the carboxy groups of the polyacrylic acid.

[0159] Next, 42.1 parts by mass of the base material of a urethane-based coating material (product name: EL-540) manufactured by Toyo-Morton Co., Ltd., 7.9 parts by mass of a curing agent, and 50 parts by mass of ethyl acetate were mixed to prepare a coating liquid for a protective layer. This coating liquid for a protective layer was applied to the surface of the barrier layer to form a coating film, and the coating film was dried at 50° C. for 10 minutes. This formation and drying of the coating film was repeated three times in total to form a protective layer, and a preform as shown in FIG. 5 was obtained. The cross-sectional thickness of the body of the preform was 3 mm, the barrier layer was 200 μm, the protective layer was 100 μm, and the weight of the preform was 20 g.

[0160] The preform was then heated to 110°C and biaxially stretched and blow molded in a blow mold to obtain a bottle having a mouth, neck, shoulder, body, and bottom and a capacity of 500 mL as shown in Fig. 1. The barrier layer and protective layer were formed on the outer surfaces of the neck, shoulder, body, and bottom of the bottle. The cross-sectional thickness of the bottle body was 0.2 mm, the barrier layer was 20 µm, and the protective layer was 10 µm.

[0161] [Example 2] A preform was obtained in the same manner as in Example 1, except that a coating solution for a barrier layer was prepared by dissolving 13.7 g of polyacrylic acid and 3.2 g of magnesium chloride in 183.2 g of methyl alcohol. The amount of magnesium chloride was 0.35 chemical equivalents relative to the total carboxyl groups of polyacrylic acid. Next, in the same manner as in Example 1, a bottle was obtained from the preform of this example.

[0162] [Example 3] A preform was obtained in the same manner as in Example 1, except that a coating liquid for a barrier layer was prepared by dissolving 13.7 g of polyacrylic acid and 1.6 g of magnesium chloride in 184.7 g of methyl alcohol. The amount of magnesium chloride was 0.177 chemical equivalents relative to the total carboxyl groups of polyacrylic acid. Next, in the same manner as in Example 1, a bottle was obtained from the preform of this example.

[0163] [Example 4] A preform was obtained in the same manner as in Example 1, except that a coating liquid for a barrier layer was prepared by dissolving 8.3 g of polyacrylic acid and 7.7 g of magnesium chloride in 184 g of methyl alcohol. The amount of magnesium chloride was 1.63 chemical equivalents relative to the total carboxyl groups of polyacrylic acid. Next, in the same manner as in Example 1, a bottle was obtained from the preform of this example.

[0164] [Example 5] A preform was obtained in the same manner as in Example 1, except that a coating liquid for a barrier layer was prepared by dissolving 6.8 g of polyacrylic acid and 4.9 g of magnesium nitrate (molecular weight: 148) in 190 g of methyl alcohol. The amount of magnesium nitrate was 0.70 chemical equivalents relative to the total carboxyl groups of polyacrylic acid. Next, in the same manner as in Example 1, a bottle was obtained from the preform of this example.

[0165] [Example 6] Polypropylene (PP) pellets were prepared. The PP was melted and injected into an injection molding machine to produce a cup support having a mouth, a body, and a bottom.

[0166] The outer surfaces of the body and bottom of the support were then subjected to a corona treatment.

[0167] Next, a barrier layer was formed on the corona-treated surface of the support using the same coating liquid for a barrier layer as in Example 1, and a protective layer was formed on the surface of the barrier layer using the same coating liquid for a protective layer as in Example 1, to produce a cup as shown in Figure 4.

[0168] [Comparative Example 1] A preform was obtained in the same manner as in Example 1, except that the barrier layer and the protective layer were not formed on the support.

[0169] Next, in the same manner as in Example 1, a bottle was obtained from the preform of this comparative example. The cross-sectional thickness of the bottle body was 0.2 mm.

[0170] [Comparative Example 2] A preform was obtained in the same manner as in Example 1, except that a coating solution for a barrier layer was prepared by dissolving only PVA in water, and a coating film was formed and dried using this coating solution for a barrier layer, a total of seven times, to form a barrier layer. The cross-sectional thickness of the body of the preform was 3 mm, the barrier layer was 200 μm, the protective layer was 100 μm, and the weight of the preform was 20 g.

[0171] Next, in the same manner as in Example 1, a bottle was obtained from the preform of this comparative example. The cross-sectional thickness of the bottle body was 0.2 mm, the barrier layer was 20 μm, and the protective layer was 10 μm.

[0172] <<Recyclability evaluation>> The bottles and cups obtained in the above Examples and Comparative Examples were crushed into flakes, and the flakes were then placed in a 1.5% by mass aqueous sodium hydroxide solution at 90°C and stirred for 15 minutes. The flakes were then filtered off, and the alkaline aqueous solution on the flake surfaces was washed away with distilled water at 20°C. The recyclability of the bottles and cups was evaluated based on the following criteria. The evaluation results are shown in Table 1. The recyclability evaluation was performed by mixing a small amount of red colorant into the protective layer coating liquid to color the protective layer. (Evaluation Criteria) A: The flakes became colorless and transparent. B: The colored protective layer remained on the flakes.

[0173] <<Gas barrier property evaluation>> The oxygen permeability of the bottles obtained in the above examples and comparative examples was measured to evaluate the gas barrier properties of the bottles. The oxygen permeability was measured in accordance with JIS K 7126-2:2006 using an oxygen gas permeability measuring device (manufactured by MOCON, product name: OX-TRAN2 / 20) under conditions of 23°C and 40% RH. The oxygen permeability value was measured for the entire bottle with the mouth closed with a jig, and was divided by the surface area of ​​the entire bottle excluding the mouth. The measurement results are shown in Table 1.

[0174] [Table 1]

[0175] As is clear from Table 1, the container of the present invention has excellent recyclability. Furthermore, the container of the present invention has gas barrier properties equivalent to those of a container having a barrier layer made only of PVA. [Explanation of symbols]

[0176] 10: Bottle 11: Mouth 12: Neck 13:Shoulder 14: Torso 15: Bottom 16: Screw part 17: Turnip 18: Support ring 19: Recess 20: Grounding part 21:Support 22: Barrier layer 23:Protective layer 30: Cup 31: Mouth 32: Torso 33: Bottom 34: Recess 35: Grounding part 36:Support 37: Barrier layer 38:Protective layer 40: Preform 41: Mouth 42: Torso 43: Bottom 44: Screw part 45: Turnip 46: Support ring 47:Support 48: Barrier layer 49:Protective layer

Claims

1. A container comprising a support, a protective layer provided on at least one surface side of the support, and a barrier layer provided between the support and the protective layer, The support comprises a thermoplastic resin, the barrier layer is a single layer, the barrier layer comprises a reaction product of a carboxyl group-containing resin and a polyvalent metal compound, The container, wherein the polyvalent metal compound is at least one selected from the group consisting of chlorides, nitrates, sulfates, phosphates, phosphites, and hypophosphites.

2. 2. The container according to claim 1, wherein the carboxy-containing resin is polyacrylic acid.

3. 3. The container according to claim 1, wherein the polyvalent metal of the polyvalent metal compound is at least one selected from the group consisting of magnesium, calcium and zinc.

4. The container according to any one of claims 1 to 3, wherein the barrier layer has a thickness of 0.1 µm or more and 200 µm or less.

5. The container according to any one of claims 1 to 4, wherein the thermoplastic resin is at least one selected from the group consisting of polyesters and polyolefins.

6. A container preform according to any one of claims 1 to 5.

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