JP5136241B2 - Multilayer structure manufacturing method and container manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a multilayer structure and a method for manufacturing a container.

  Surfaces of solid substances such as silicone rubber, fluororubber, and polyethylene resin are often hydrophobic and water repellent, and are generally difficult to bond, print, and coat with other members. Examples of a method for modifying the surface characteristics of such a solid substance include an ultraviolet irradiation method and a corona discharge treatment. For example, Patent Document 1 discloses a technique for improving the wettability and adhesion of a coating by irradiating the surface of a hydrophobic plastic with ultraviolet rays using a high-pressure mercury lamp made of synthetic quartz.

Japanese Patent Laid-Open No. 5-68934

However, such a method has an insufficient surface modification effect and has environmental problems and economic problems such as large-scale and expensive equipment.

  An object of the present invention is to produce a multilayer structure that is free from environmental problems and economical problems and is excellent in adhesion to other members, printing characteristics, coating characteristics, and the like.

That is, this invention is a manufacturing method of the multilayered structure which includes the process of the following (1)-(3) in order.
(1) A flame treatment is performed by bringing a flame in which a mixed gas containing a metal alkoxide and / or an alkyl metal compound and a combustible gas into contact is brought into contact with at least one surface of the substrate layer, and a surface treatment layer precursor ( 1) forming step (2) washing the surface treatment layer precursor (1) with a polar solvent to form the surface treatment layer precursor (2) (3) the surface treatment layer precursor (2) ) Is dried to form a surface treatment layer

In another aspect, the present invention is a method of manufacturing a container by joining the container members to each other, and the following steps (1) to (3) are sequentially performed: It is a manufacturing method of the container containing.
(1) A step of applying a coating liquid containing the polymer component (A) and a liquid medium to at least the inner surface of the container member to form a film. (2) Container members having a film formed on at least the inner surface. (3) The step of dry heat-treating the primary container

  According to the present invention, there is no environmental problem or economic problem even on a highly hydrophobic substrate surface, and a multilayer structure excellent in adhesion to other members, printing characteristics, coating characteristics, etc. The body can be manufactured.

  In step (1) in the method for producing a multilayer structure of the present invention, at least one surface of the base material layer is contacted with a flame obtained by burning a mixed gas containing a metal alkoxide and / or an alkyl metal compound and a combustible gas. And performing a flame treatment to form the surface treatment layer precursor (1). The material which comprises the said base material layer is not specifically limited, A metal, resin, wood, ceramic, glass etc. are mentioned. As the resin, a thermoplastic resin or a thermosetting resin can be used, but a thermoplastic resin is preferable.

  The thermoplastic resin is not particularly limited, and examples thereof include olefin resins such as polyethylene, ethylene-α-olefin copolymer, polypropylene, and polyester resins. Two or more kinds of thermoplastic resins may be used. In addition, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, anti-blocking agents, waxes, petroleum resins, antistatic agents, inorganic fillers as fillers (for example, “Plastic and Rubber Additives Handbook” (See, for example, 1970)) and known additives may be used.

  The substrate layer used in the present invention may be a single layer or two or more layers. For example, it is preferable to use a multilayer base material layer in which an olefin resin layer and a gas barrier resin layer are laminated from the viewpoint of gas barrier properties of the resulting multilayer structure. Examples of the gas barrier resin include a polyvinyl alcohol polymer, an ethylene-vinyl alcohol copolymer, a polyamide resin, and an aliphatic polyketone.

When a multi-layer base material layer in which an olefin resin layer and a gas barrier resin layer are laminated is used as the base material layer, it is preferable to have an adhesive resin layer between both layers. Such a multilayer base material layer has a high interlayer strength between the olefin-based resin layer and the gas barrier resin layer, so that a base material layer having excellent gas barrier properties and strength can be obtained.
Examples of the adhesive resin include modified polyolefin, polyurethane resin, and polyester resin. As the modified polyolefin, a carboxylic acid-modified polyolefin, particularly maleic anhydride-modified polyolefin is preferably used.
When the multilayer structure of the present invention is used as a container member and the substrate layer is a multilayer substrate layer in which an olefin resin layer and a gas barrier resin layer are laminated, the gas barrier resin layer is close to the inside of the container. Thus, it is preferable to use it.

  A surface treatment layer precursor (1) is subjected to a flame treatment by bringing at least one surface of the base material layer into contact with a flame in which a mixed gas containing a metal alkoxide and / or an alkyl metal compound and a combustible gas is combusted. Form. By performing flame treatment on the base material layer in this way, organic impurities present on the surface of the base material layer disappear due to oxidation, water attached to the surface of the base material layer is also lost, and in the flammable gas The surface treatment layer precursor (1) which is a metal oxide layer is formed on the surface of the base material layer by the metal alkoxide and / or the alkyl metal compound.

  In the step (2) in the method for producing a multilayer structure of the present invention, the surface treatment layer precursor (1) formed in the step (1) is washed with a polar solvent, and the surface treatment layer precursor (2) is obtained. It is a process of forming. Here, the polar solvent is a hydrophilic solvent, and preferably a solvent that can be dissolved in water. Specific examples include alcohols (methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, etc.), ketones (acetone, diethyl ketone, etc.), dimethylformamide, dimethyl sulfoxide, and the like. Alcohol mixtures, ketones and water-ketone mixtures are preferred. Moreover, it does not specifically limit as a washing | cleaning method, The method etc. which are immersed in the said polar solvent are mentioned.

  Step (3) in the method for producing a multilayer structure of the present invention is a step of drying the surface treatment layer precursor (2) formed in step (2) to form a surface treatment layer. The drying treatment is a treatment for removing the polar solvent and moisture attached to the surface treatment layer precursor (2). Usually, it may be aged at a humidity of 50% RH or less and a temperature of 20 to 100 ° C. for 1 second to 24 hours.

Known metal alkoxides and alkyl metal compounds contained in the mixed gas can be used.
The metal in the metal alkoxide or the alkyl metal compound is, for example, Na, Ba, Cu, Al, Si, Ti, Ge, Zr, V, W, Y, etc., preferably Si, Ti, Al, or Zr. In view of improving the adhesion between the base material layer and the surface treatment layer or improving the adhesion between the surface treatment layer and the film described later, Si is more preferable. Examples of the hydrocarbon moiety in the metal alkoxide and the alkyl group in the alkyl metal compound include CH3, C2H5, C3H7, C4H9, C5H11, and C6H13.

Examples of metal alkoxides include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, dimethoxydiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, vinyl Trimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, chlorotrimethoxysilane, triethoxyaluminum, isopropoxyzirconium, trimethoxytitanate, tetrapropoxytitanate, methylpropylacrylic triethoxysilane, glycidylpropyltriethoxysilane, aminopropyl Examples include triethoxysilane and benzyltrimethoxysilane.
Examples of the alkyl metal compound include tetramethyldisiloxane, tetraethyldisiloxane, hexamethyldisiloxane, octamethylcyclotetrasiloxane, and dimethylsiloxane.

  The metal alkoxide and alkyl metal compound contained in the mixed gas may contain only the metal alkoxide or only the alkyl metal compound, or may contain both the metal alkoxide and the alkyl metal compound. Moreover, the metal alkoxide and the alkyl metal compound to be used may be one type, or two or more types may be used in combination.

  The mixed gas further contains a combustible gas. As the combustible gas, known ones can be used. For example, methane gas, ethane gas, propane gas, butane gas and natural gas mixed with them, city gas, liquefied petroleum gas (LP gas), pentane, hexane, ethylene, Examples include hydrocarbon gases such as propylene, butene, pentene, acetylene, benzene, toluene, xylene, naphthalene, cyclopropane, cyclohexane, cyclopentene, and cyclohexene, and mixed gases of these hydrocarbon gases with oxygen and hydrogen. .

  When the mixed gas is burned, a gas containing oxygen such as air and a mixed gas are usually mixed and burned. The volume ratio when mixing the mixed gas and air is preferably 3 to 80 with respect to the mixed gas 1.

The amount of the metal alkoxide and / or alkyl metal compound contained in the mixed gas of the mixed gas and air depends on the adhesion between the base material layer and the surface treatment layer and the adhesion between the surface treatment layer and the film described later. From the viewpoint of the uniformity of the thickness of the surface treatment layer to be formed, the total is preferably a molar fraction of 10 ⁻¹ to 10 ⁻⁷ , preferably a molar fraction of 10 ⁻² to 10 ^−6. More preferably it is.

A gas burner is usually used for the flame treatment. The flame temperature and treatment time during the flame treatment vary depending on the type, shape, thickness, etc. of the base material layer, but are usually set appropriately so that the surface of the base material layer is 50 to 100 ° C.
The thickness of the surface treatment layer provided by the steps (1) to (3) in the method for producing a multilayer structure of the present invention is preferably 1000 nm or less, more preferably 5 to 500 nm, and particularly preferably 10 to 300 nm. It is desirable to set processing conditions.

  The temperature of the flame is usually 900 to 2000 ° C. The time for irradiating the flame is usually 0.1 to 5 seconds, preferably 0.1 to 1 second. In order to prevent deformation of the base material layer due to heat, it is necessary to keep the flame irradiation time to a minimum.

  The shape of the multilayer structure obtained by the method of the present invention is not particularly limited and is appropriately selected depending on the application and purpose. The multilayer structure may be a container member. The container member in this invention should just be a member which can form the container which has an opening part by joining each member. For example, the member which a container is obtained by joining a pair of members may be sufficient, and the member further divided finely may be sufficient. As the number of members increases, the number of joints increases and the process becomes complicated, and thus a pair of members is preferable.

  The method for producing the container member is not particularly limited. For example, after using the base material layer shaped in the shape of a container member in advance to form the above-mentioned surface treatment layer, using the film or sheet-like base material layer, forming the above-mentioned surface treatment layer, the container member shape The method of shaping is mentioned. Moreover, there is no restriction | limiting in particular about the shaping method, For example, it can manufacture by injection molding, press molding, etc.

In the step (1) in the method for producing a container by joining container members together, a coating liquid containing a polymer component (A) and a liquid medium is applied to at least the inner surface of the container member to form a film. It is a process to do.
The inner surface of the container member is a surface that becomes the inner side of the container when the container members are joined to each other, and a surface that comes into contact with the content when the content is injected into the container. .

  Since the container obtained by the method of the present invention is usually required to have a gas barrier property, the polymer component (A) includes polyvinyl alcohol (PVA), an ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride ( PVDC), polyacrylonitrile (PAN), polysaccharides such as cellulose, polyacrylic acid and esters thereof, and urethane resins, but can be easily dissolved in an aqueous liquid medium and easy to handle. From the viewpoint of gas barrier properties of the obtained container, the polymer component (A) is preferably a polymer component containing a hydroxyl group. Examples of the polymer component containing the hydroxyl group include PVA, EVOH, and cellulose.

  From the viewpoint of gas barrier properties of the container obtained by the method of the present invention, (i) a resin having a hydroxyl group and a second functional group capable of reacting with the hydroxyl group in one molecule, or (ii) a resin having a hydroxyl group It is preferably a mixture with a resin having a second functional group capable of reacting with a hydroxyl group. Hereinafter, the case of (i) and the case of (ii) may be collectively referred to as “resin component having a hydroxyl group and a second functional group”.

The second functional group capable of reacting with the hydroxyl group is preferably a functional group capable of forming a covalent bond or an ionic bond with the hydroxyl group. Specific examples include polar groups such as a carboxyl group, an amino group, a sulfonic acid group, a carboxylate group, and an ammonium group.

  Examples of the resin containing a hydroxyl group and a second functional group in one molecule include vinyl alcohol-acrylic acid copolymer, vinyl alcohol-methacrylic acid copolymer, vinyl alcohol-vinylamine copolymer, acrylic acid-vinylamine copolymer. And a methacrylic acid-vinylamine copolymer.

  Examples of the resin having a second functional group capable of reacting with a hydroxyl group include polyacrylic acid, polymethacrylic acid, polyvinylamine, acrylic acid-methacrylic acid copolymer, vinylamine- (meth) acrylic acid copolymer, and the like. Can be mentioned.

  When the polymer component (A) is a mixture of a resin having a hydroxyl group and a resin having a second functional group capable of reacting with the hydroxyl group, the resin having a hydroxyl group is a polyvinyl alcohol polymer (A-1). And the resin having a second functional group capable of reacting with a hydroxyl group is preferably a polymer component (A-2) containing a carboxyl group.

  A polyvinyl alcohol-type polymer (A-1) is a polymer which has a vinyl alcohol unit as a main component. Examples of such “polyvinyl alcohol” include polymers obtained by hydrolyzing the acetate portion of vinyl acetate polymers, vinyl trifluoroacetate polymers, vinyl formate polymers, vinyl pivalate polymers, t- Examples include polymers obtained by hydrolyzing butyl vinyl ether polymers, trimethylsilyl vinyl ether polymers, etc. (For details on “polyvinyl alcohol”, see, for example, “Poval World”, “PVA World”, 1992, Kokai Co., Ltd. Molecular publication society; Nagano et al., “Poval”, 1981, see Kobunshi Shuppankai). The degree of “saponification” of the ester portion of the polymer is preferably 70 mol% or more, more preferably 85 mol% or more, and more preferably 98% mol or more of a so-called completely saponified product. The degree of polymerization of the vinyl alcohol polymer (A-1) used is more preferably 100 or more and 5000 or less, and 200 or more and 3000 or less.

  Further, as the polyvinyl alcohol polymer (A-1), so-called polyvinyl alcohol derivatives having a functional group other than a hydroxyl group can also be used. Examples of the functional group other than a hydroxyl group include an amino group, a thiol group, a carboxyl group, a sulfonic acid group, Examples include phosphate groups, carboxylate groups, sulfonate ion groups, phosphate ion groups, ammonium groups, phosphonium groups, silyl groups, siloxane groups, alkyl groups, allyl groups, fluoroalkyl groups, alkoxy groups, carbonyl groups, and halogen groups. it can. A part of hydroxyl groups in PVA may be replaced with one or more of these functional groups. The polyvinyl alcohol polymer (A-1) in the present invention may be a copolymer containing a vinyl alcohol unit and an α-olefin unit such as ethylene or propylene. When polyvinyl alcohol contains a vinyl alcohol unit and an α-olefin unit in one molecule, in the present invention, a resin having an α-olefin unit content of 20 mol% or less is referred to as PVA. Here, the α-olefin unit means a structural unit derived from an α-olefin.

  The polymer component (A-2) containing a carboxyl group is one selected from the group consisting of polyacrylic acid, polymethacrylic acid, a polyacrylic acid partial neutralized product, and a polymethacrylic acid partial neutralized product. The above polymer component is preferable. A copolymer of acrylic acid and methacrylic acid can also be used. The weight average molecular weight of the polymer component (A-2) containing the carboxyl group is preferably in the range of 2000 to 10000000, more preferably 100000 to 5000000.

The partially neutralized polyacrylic acid or the partially neutralized polymethacrylic acid can be usually obtained by adding an alkali to an aqueous solution of polyacrylic acid. By adjusting the amount ratio of polyacrylic acid or polymethacrylic acid and alkali, a desired degree of neutralization can be obtained. Further, a completely neutralized product of polyacrylic acid or a completely neutralized product of polymethacrylic acid can be converted into a partially neutralized product by ion exchange. Here, the neutralization degree of the polyacrylic acid partial neutralized product or the polymethacrylic acid partial neutralized product is defined by the following equation. The neutralized polyacrylic acid partial or polymethacrylic acid partially neutralized product preferably has a degree of neutralization of 0.1% to 20% from the viewpoint of gas barrier properties and transparency of the resulting container.
Degree of neutralization = (A / B) × 100
A: Number of moles of neutralized carboxyl group contained in 1 g of polyacrylic acid or polymethacrylic acid B: Number of moles of carboxyl group before neutralization contained in 1 g of polyacrylic acid or polymethacrylic acid

  When the polymer component (A) of the present invention is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the hydroxyl group contained in the polymer component (A) The molar ratio of the carboxyl group is preferably hydroxyl group: carboxyl group = 30: 70 to 95: 5, more preferably 70:30 to 95: 5. From the viewpoint of gas barrier properties of the resulting container, the total weight of hydroxyl groups and carboxyl groups contained in the polymer component (A) is preferably 30 to 60%, more preferably 35 to 55%. The total weight of the hydroxyl group and the carboxyl group is a value when the weight of the polymer component is 100%.

  When the polymer component (A) is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the molar ratio of the hydroxyl group to the carboxyl group contained in the polymer component is , NMR method, IR method and the like. For example, in the case of the IR method, a calibration curve is obtained using a sample having a known molar ratio of hydroxyl group to carboxyl group, and the molar ratio of the hydroxyl group to carboxyl group of the measurement sample can be calculated using this. When using a vinyl alcohol homopolymer and an acrylic acid homopolymer and / or methacrylic acid monopolymer, the number of moles of hydroxyl groups and carboxyl groups is determined in advance from the weight, and the molar ratio of hydroxyl groups to carboxyl groups is calculated. can do. Further, the total weight measurement of the hydroxyl group and carboxyl group contained in the polymer component can be determined by NMR method, IR method, etc. as in the molar ratio. For example, in the IR method, a calibration curve is obtained for a polyol polymer having a known number of polyol units and a polycarboxylic acid polymer having a known number of polycarboxylic acid units, and using these calibration curves, a hydroxyl group in a measurement sample is obtained. And the total weight of carboxyl groups can be calculated. Moreover, when using a vinyl alcohol single polymer and an acrylic acid single polymer and / or a methacrylic acid single polymer, the weight of a hydroxyl group and a carboxyl group can be calculated | required from the weight previously, and this total amount can be calculated | required.

  The polymer component (A) in the present invention comprises a polyvinyl alcohol-based resin (A-1) and polyacrylic acid, polymethacrylic acid, a polyacrylic acid partial neutralized product, and a polymethacrylic acid partial neutralized product. When the polymer component (A-2) containing a carboxyl group selected from is used, the polyvinyl alcohol polymer 95 to 5% by weight and the polymer component (A-2) 5 to 95% by weight containing a carboxyl group It is preferable that it is a mixture. However, this ratio is a value when the weight of the polymer component (A) contained in the coating liquid is 100%. The proportions of the polyvinyl alcohol polymer (A-1) and the polymer component (A-2) containing a carboxyl group are (A-1) 50 to 95% and (A-2) 5 to 50%. More preferably, (A-1) is 70 to 90%, and (A-2) is more preferably 10 to 30%.

  The coating liquid in the present invention contains the polymer component (A) and a liquid medium. The liquid medium is not particularly limited, but is preferably a liquid medium capable of dissolving the polymer component (A) from the viewpoint of coatability. Further, it is necessary that the liquid medium hardly remains in the container finally obtained. Therefore, it is preferable that the liquid medium is easy to remove. As will be described later, when the coating liquid contains the clay mineral (B), it is preferable to use a liquid medium in which the clay mineral (B) swells and is easily cleaved.

  Examples of the liquid medium used in the present invention include water, alcohols (methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, etc.), dimethylformamide, dimethyl sulfoxide, acetone and the like. -Alcohol mixtures are preferably used.

  When the polymer component (A) is a polymer component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the coating solution is alkaline from the viewpoint of the water resistance of the resulting container. It is preferable that a metal ion (C) is included. Examples of the alkali metal ion (C) include sodium ion, lithium ion, and potassium ion. The weight of the alkali metal ion (C) contained in the coating liquid is preferably 0.2 to 5 parts by weight, more preferably 0.2 to 2 parts by weight with respect to 100 parts by weight of the polymer component (A). Part.

The alkali metal ion (C) is usually derived from an alkali metal ion donating compound. That is, when the polymer component (A) is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the coating liquid preferably contains an alkali metal ion donating compound. Examples of the alkali metal ion donating compound include sodium hydroxide, sodium hypophosphite, lithium hydroxide, potassium hydroxide and the like. When a partially neutralized polyacrylic acid obtained by adding sodium hydroxide to a polyacrylic acid aqueous solution is used as the polymer component (A), the partially neutralized polyacrylic acid is donated with alkali metal ions. Acts as a compound.
Examples of the alkali metal ion donating compound include clay mineral (B) having an alkali metal ion between layers. Two or more kinds of alkali metal ion donor compounds may be used in combination. From the viewpoint of gas barrier properties of the resulting container, the coating liquid preferably contains a clay mineral (B) having an alkali metal ion between layers.

  The clay mineral (B) is a compound having a layered structure in which unit crystal layers are usually stacked in a raw material state. Here, the layered structure refers to a structure in which surfaces in which atoms are strongly bonded by a covalent bond or the like and densely arranged are stacked substantially in parallel by a weak binding force such as van der Waals force. Examples of the clay mineral (B) include montmorillonite, beidellite, nontronite, saponite, soconite, stevensite, hectorite, tetrasilic mica, sodium teniolite, muscovite, phlogopite, and the like. In addition, those obtained by treating these clay minerals (B) with an organic substance such as ion exchange and improving dispersibility (see Asakura Shoten, “Encyclopedia of Clay”) can also be used as clay minerals containing alkali metal ions. As the organic substance for treating the clay mineral (B), quaternary ammonium salts such as dimethyl distearyl ammonium salt and trimethyl stearyl ammonium salt, phosphonium salts, imidazolium salts and the like can be used.

From the viewpoint of enhancing the gas barrier properties of the resulting container, the alkali metal ion is preferably a sodium ion, and a sodium ion-containing clay mineral is preferable as the sodium ion donating compound for donating the sodium ion. From the viewpoint of dispersibility in the coating liquid, it is particularly preferable to use a clay mineral (B) having a property of swelling and cleaving in a liquid medium. An example of such a clay mineral (B) is montmorillonite having sodium ions between layers.
The degree of the property that the clay mineral (B) swells and cleaves in the solvent can be evaluated by the following test. The swellability of the clay mineral (B) is preferably 5 or more, more preferably 20 or more in the following swellability test. On the other hand, the cleavage property of the clay mineral (B) is preferably 5 or more, and more preferably 20 or more in the following cleavage test.

(Swellability test)
Place 100 ml of liquid medium in a 100 ml graduated cylinder, and gradually add 2 g of clay mineral (B). After standing at 23 ° C. for 24 hours, the volume (ml) of the clay mineral dispersion layer is read from the scale of the interface between the clay mineral dispersion layer and the supernatant in the graduated cylinder. It shows that swelling property is so high that this numerical value (swelling value) is large.

[Cleavage test]
Gradually add 30 g of clay mineral (B) into 1,500 ml of liquid medium, and disperser (Asada Tekko Co., Ltd., Despa MH-L, blade diameter 52 mm, rotation speed 3,100 rpm, container capacity 3 L, between bottom and blades At a peripheral speed of 8.5 m / min and at 23 ° C. for 90 minutes, 100 ml of this dispersion is collected in a graduated cylinder. After standing for 60 minutes, the volume (ml) of the clay mineral dispersion layer is read from the scale of the interface between the clay mineral dispersion layer and the supernatant in the graduated cylinder. The larger this numerical value (cleavage value), the higher the cleavage property.

  The clay mineral (B) preferably has an aspect ratio of 30 to 3,000, more preferably 30 to 1,500, from the viewpoint of dispersibility in the coating liquid and gas barrier properties of the resulting container. The aspect ratio (Z) of the clay mineral (B) is defined by the formula: Z = L / a. In the formula, L is the average particle diameter of the clay mineral (B), a is the unit thickness of the clay mineral (B), that is, the thickness of the unit crystal layer of the clay mineral (B), Analytical method (see "Guide to Instrumental Analysis (a)" (1985, published by Kagaku Dojinsha, supervised by Jiro Shiokawa), page 69).

  The average particle diameter of the clay mineral (B) is a particle diameter (volume-based median diameter) obtained by a diffraction / scattering method in a liquid medium. That is, the particle size distribution that is most consistent with the diffraction / scattering pattern is calculated from the diffraction / scattering pattern obtained when light passes through the dispersion of the clay mineral (B) by the Mie scattering theory or the like. be able to. Specifically, for example, the measurement range of the particle size distribution is divided into appropriate sections, the representative particle diameter is determined for each section, and the particle size distribution, which is originally a continuous quantity, is converted into a discrete quantity and calculated. A method is mentioned.

  In the present invention, as a solvent for swelling and cleaving the clay mineral (B), when the clay mineral (B) is a hydrophilic swelling clay mineral, water, alcohols (methanol, ethanol, propanol, isopropanol, ethylene glycol) , Diethylene glycol, etc.), dimethylformamide, dimethyl sulfoxide, acetone and the like, among which water, alcohols, and water-alcohol mixtures are preferred.

  When the clay mineral (B) is an organically modified clay mineral, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as ethyl ether and tetrahydrofuran, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone Aliphatic hydrocarbons such as n-pentane, n-hexane and n-octane, halogenated hydrocarbons such as chlorobenzene, carbon tetrachloride, chloroform, dichloromethane, 1,2-dichloroethane and perchloroethylene, ethyl acetate, Methyl methacrylate, dioctyl phthalate, dimethylformamide, dimethyl sulfoxide, methyl cellosolve, silicone oil and the like can be used as the liquid medium.

  The amount of the clay mineral (B) contained in the coating liquid is not particularly limited, but from the viewpoint of gas barrier properties of the resulting container, the volume ratio of the polymer component (A) and the clay mineral (B) is: (A) / (B) = 50/50 to 99/1 is preferable, and 70/30 to 99/1 is more preferable.

  It is preferable to add a surfactant to the coating solution. A film formed by applying such a coating solution has excellent adhesion to the container member. The content of the surfactant is usually 0.001 to 5% by weight in 100% by weight of the coating liquid.

  As the surfactant, a known surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be used. In particular, an alkali metal salt of a carboxylic acid having an alkyl chain having 6 to 24 carbon atoms, an ether type nonionic surfactant such as a polydimethylsiloxane-polyoxyethylene copolymer (silicone nonionic surfactant) ) Or a fluorine-type nonionic surfactant (fluorine-based nonionic surfactant) such as a perfluoroalkylethylene oxide compound is preferable from the viewpoint of improving adhesion.

Further, known additives such as antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents and the like can be added to the coating liquid according to the purpose and application. These additives may be used alone or in combination of two or more.
Moreover, when a coating liquid contains a clay mineral (B), it is preferable to carry out a high pressure dispersion process and to disperse | distribute this clay mineral (B) uniformly.

  A crosslinking agent may be added to the coating solution. When the polymer component (A) is a polymer component containing a hydroxyl group, the crosslinking agent used is a titanium coupling agent, silane coupling agent, melamine coupling agent, epoxy coupling agent, isocyanate. Examples of such coupling agents include carbodiimide coupling agents, copper compounds, and zirconium compounds. Only one kind of these crosslinking agents may be used, or two or more kinds may be appropriately mixed and used.

When the crosslinking agent is added to the coating solution, it is usually adjusted by a method in which a crosslinking agent solution in which 10 to 90% by weight of the crosslinking agent is previously dissolved in a solvent such as alcohol is added to the coating solution.
In the case of using a chelate compound as the crosslinking agent, the coating solution is preferably acidic from the viewpoint of the stability of the coating solution after mixing the crosslinking agent.

In the step (1) of the container manufacturing method of the present invention, the coating liquid described above is applied to at least the inner surface of each container member, and a film is formed on the surface. Further, an anchor coat layer may be provided in advance on the surface treatment layer for the purpose of improving the adhesion between the surface treatment layer and the film.
In one preferable aspect, in the step (1), the coating liquid is applied to the inner surface of each container member and the joint surface with the other container member, and a film is formed on the inner surface and the joint surface. Examples of the method for applying the coating liquid to the container member include a dipping method and a spray coating method. When the member is flat, gravure method such as direct gravure method, reverse gravure method, roll coating method such as two roll beat coating method, bottom feed three reverse coating method, doctor knife method, die coating method, bar The coating liquid can also be applied by a method such as a coating method. The film thickness of the film formed by applying the coating liquid is usually determined to be 1 to 50 μm as the thickness of the dried film in the resulting container.

Step (2) in the container manufacturing method of the present invention is a step of obtaining a primary container by joining container members each having a film formed at least on the inner surface. A film containing the polymer component (A) and the liquid medium is formed on the inner surface of the container member obtained in the step (1) by applying a coating liquid containing the polymer component (A) and the liquid medium. ing. In the step (2) in the method for producing a container, a container member obtained by removing the liquid medium from the film containing the polymer component (A) and the liquid medium may be used, and the method for producing the container without removing the liquid medium. A container member in which a film containing the polymer component (A) obtained in step (1) and a liquid medium is formed may be used as it is. In the former case, it is necessary to heat and pressurize when joining the container members. In the latter case, when a container member having a film formed on the bonding surface is used, the members can be bonded to each other without applying pressure by removing the liquid medium from the film by heating. Therefore, it is preferable to use a container member in which a film containing a liquid medium is formed on the inner surface and the bonding surface. Examples of the method for removing the liquid medium include a method of drying at a temperature of usually 100 ° C. or lower, preferably about 30 to 80 ° C. The removal of the liquid medium is preferably performed in an atmosphere having a water vapor concentration of less than 50 g / m ³ .

Examples of a method for bonding container members include a method of heat-sealing bonding surfaces, that is, a method of bonding at least the vicinity of the bonding surfaces in a state where the bonding surfaces are overlapped or butted together. Further, a flange for joining may be provided in advance on the container member, and the flanges may be heat sealed. In this case, the flange becomes the joint surface. The conditions for normal heat sealing are that the temperature is equal to or higher than the melting point of the thermoplastic resin constituting the container member, the time is 1 second to 1 hour, and the pressure is 0.001 kg / cm ^{2 to} 100 kg / cm ² . As described above, when a container member in which a film containing a liquid medium is formed on the inner surface and the bonding surface is used, the bonding surface can be overlapped or butted together to heat and remove the liquid medium. Since it can join without pressing and it is excellent in production efficiency, it is preferable.

Step (3) in the container manufacturing method of the present invention is a step of subjecting the primary container obtained in step (2) to a dry heat treatment.
By performing the dry heat treatment, the adhesion between the film formed by applying the coating liquid and drying it and the surface treatment layer or between the films is improved. In particular, when the polymer component (A) is a polymer component having a hydroxyl group and a second functional group, when a dry heat treatment is performed, the hydroxyl group reacts with the second functional group, and the layer has excellent gas barrier properties. (Hereinafter referred to as a gas barrier layer). When the liquid medium is contained in the film, the liquid medium can be removed by dry heat treatment. The dry heat treatment conditions are a water vapor concentration of less than 50 g / m ³ and a temperature of 100 ° C. or higher, preferably a water vapor concentration of 0 to 40 g / m ³ and a temperature of 120 ° C. or higher and 200 ° C. or lower. The time for the dry heat treatment is usually 1 second to 1 hour.

  In the container manufacturing method of the present invention, when the polymer component (A) is a polymer component having a hydroxyl group and a second functional group, the container member having a film formed on the inner surface obtained in the step (1) The reaction between the hydroxyl group of the polymer component (A) contained in and the second functional group does not proceed. The same applies to the film formed on the joint surface of the container member. Therefore, even if a film is formed on the bonding surface of the container member, bonding can be performed in the step (2). Further, even if no film is formed on the joint surface of the container member, the reaction of the polymer component (A) contained in the film proceeds in the step (3), so that a strong gas barrier layer is also formed at the interface between the container members. A formed container is obtained. That is, since bonding is possible even if the bonding surface is covered with a film, it is not necessary to form the film with care not to cover the bonding surface with the film. Therefore, a container can be manufactured efficiently.

  In one aspect of the container manufacturing method of the present invention, step (2) and step (3) may be performed simultaneously. That is, the container members can be joined under the dry heat treatment conditions in the step (3). In particular, in the step (2), when using the container member from which the liquid medium is removed from the film containing the polymer component (A) obtained in the step (1) and the liquid medium, the container members are joined together under dry heat treatment conditions. By doing so, the production efficiency of a container can be improved.

  In the method for producing a multilayer structure of the present invention, after the step (3), as the step (4), a coating liquid containing the polymer component (A) and the liquid medium is applied on the surface treatment layer. And a step of forming a film. As the polymer component (A), those described above can be used, but a polymer component containing a hydroxyl group is preferred, and the liquid media and the coating method described above can be used. Furthermore, the coating solution may contain the above-mentioned clay mineral (B). Moreover, when using the obtained multilayer structure as a film or a sheet, you may perform the above-mentioned dry heat processing. Moreover, when this multilayer structure is a container member, the manufacturing method of this container member is not specifically limited. For example, after forming the above-mentioned surface treatment layer using a base material layer shaped in the shape of a container member in advance, a method of forming a film, using a film or sheet-like base material layer, After the formation, there is a method of forming a film and shaping the container member.

  When the method for producing a multilayer structure includes the step (4), and the multilayer structure is a container member, the step (1 ′) in the method for producing a container of the present invention includes a film formed on at least the inner surface. This is a step of joining the container members to obtain a primary container, and corresponds to the step (2) in the method for producing a container when the method for producing the multilayer structure does not include the step (4). A film containing the polymer component (A) and a liquid medium is formed on the inner surface of the container member. In step (1 ′) in the container manufacturing method, as in step (2) in the container manufacturing method, a container member in which the liquid medium is removed from the film containing the polymer component (A) and the liquid medium is used. Alternatively, the container member in which the film containing the polymer component (A) and the liquid medium is formed may be used as it is without removing the liquid medium.

  When the manufacturing method of the multilayer structure includes the step (4), and the multilayer structure is a container member, the step (2 ′) in the manufacturing method of the container of the present invention is a step of dry heat-treating the primary container. Yes, this method corresponds to step (3) in the method for manufacturing a container when the method for manufacturing the multilayer structure does not include the step (4). The effects and conditions of the dry heat treatment are the same as in step (3) in the above-described container manufacturing method.

Furthermore, in one aspect of the present invention, after the step (3) or the step (2 ′) in the method for producing a container, a step of wet heat treatment may be further included. The wet heat treatment is a treatment for holding in an atmosphere having a water vapor concentration of more than 290 g / m ³ at a temperature of 100 ° C. or higher or in water of 80 ° C. or higher. The time for the wet heat treatment is usually 1 second to 1 hour. If the water vapor concentration at 100 ° C. above the temperature of the treatment in an atmosphere of 290 g / m ³ greater, the temperature is preferably in the range of 120 to 200 [° C., the water vapor concentration is preferably in the range of 500~20000g / m ^3. By performing the wet heat treatment, the container can be further improved in gas barrier properties.
There is no restriction | limiting in particular in the thickness of the container obtained by this invention, Usually, it is the range of 0.5-10 mm.

  Since the container of the present invention is excellent in scratch resistance and gas barrier properties, it is optimal as a packaging and transportation container for various liquids. Furthermore, the container of the present invention is also suitable for food containers such as foods, seasonings and drinking water, non-food containers such as cosmetics and detergents, and medical containers such as infusions. Further, it can be suitably used as a tank for storing various organic solvents such as gasoline, and is particularly suitable as a fuel tank for automobiles.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Measurement methods for various physical properties are described below.

[Thickness measurement]
The thickness of 0.5 μm or more was measured using a commercially available digital thickness gauge (contact thickness gauge, trade name: ultra-high precision deci-micro head MH-15M, manufactured by Nippon Optical Co., Ltd.) The thickness of less than 0.5 μm was determined by cross-sectional observation with a transmission electron microscope (TEM).

(Particle size measurement)
Measurement was performed using a laser diffraction / scattering particle size distribution analyzer (LA910, manufactured by Horiba, Ltd.). The coating liquid (1) and the coating liquid (2) are diluted, and the average particle diameter of the inorganic layered compound in the diluted liquid is measured with a flow cell at an optical path length of 4 mm. The average particle size L of the compound was considered. In addition, without diluting the coating liquid (1) and the coating liquid (2), the average particle diameter of the inorganic layered compound in the coating liquid was measured with a paste cell at an optical path length of 50 μm. When the average particle size L obtained with the diluent almost coincided, the inorganic layered compound was determined to be sufficiently swollen and cleaved in the coating solution.

[Aspect ratio calculation]
Using an X-ray diffractometer (XD-5A, manufactured by Shimadzu Corporation), the inorganic layered compound itself was subjected to diffraction measurement by a powder method. Thus, the unit thickness a of the inorganic layered compound is obtained,
Using the particle diameter L obtained by the above method, the aspect ratio Z was calculated by the equation Z = L / a. In addition, about what dried coating liquid (1) and coating liquid (2), the X-ray-diffraction measurement was performed, and it confirmed that the surface interval of the inorganic layered compound was spreading.

[Dry heat treatment]
The multilayer structure of 210 mm × 300 mm was subjected to a dry heat treatment for 60 minutes in an oven at 150 ° C. and 2% RH.

[Drying treatment]
A multilayer structure of 210 mm × 300 mm was allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH.

Cross cut test The surface of the multi-layer structure is cut with a grid cut of 1 mm square 100 mm so as to penetrate the film with a cutter knife, and cellophane tape (made by Nichiban Co., Ltd., 24 mm width) is applied to this, Subsequently, it peeled off to the orthogonal | vertical direction and evaluated by the peeling number per 100 grids.
○ ・ ・ ・ No peeling × ・ ・ ・ Partial peeling or whole surface peeling

Fuel immersion test The multilayer structure was immersed in CE10 (toluene / isooctane / ethanol = 45/45/10 wt%) as a simulated fuel at 65 ° C. for 200 hours. Thereafter, peeling of the coating film was visually confirmed and evaluated.
○ No peeling, × Partial peeling or whole surface peeling

[Preparation of coating solution]
Preparation of Coating Liquid (1) A dispersion kettle (trade name: Despa MH-L, manufactured by Asada Tekko Co., Ltd.), 1300 g of ion-exchanged water (specific electric conductivity 0.7 μs / cm or less) and polyvinyl alcohol (AQ2117) ;(stock)
130 g of Kuraray, degree of saponification; 99.6%, degree of polymerization 1,700) were mixed and heated to 95 ° C. under low speed stirring (1500 rpm, peripheral speed 4.1 m / min). The mixed system is 30 at the same temperature.
After stirring for minutes to dissolve the polyvinyl alcohol, it was cooled to 60 ° C. to obtain an aqueous polyvinyl alcohol solution. While stirring the polyvinyl alcohol aqueous solution (60 ° C.) under the same conditions as described above, an alcohol aqueous solution obtained by mixing 122 g of 1-butanol, 122 g of isopropyl alcohol and 520 g of ion-exchanged water was added dropwise over 5 minutes. After completion of the dropping, switching to high-speed stirring (3,000 rpm, peripheral speed = 8.2 m / min), 65 g of high-purity montmorillonite (trade name: Kunipia G; manufactured by Kunimine Industry Co., Ltd.) was gradually added to the stirring system, After completion of the addition, stirring was continued at 60 ° C. for 60 minutes. Thereafter, 243 g of isopropanol was further added to 15
Then, the mixture is cooled to room temperature, and a nonionic surfactant (polydimethylsiloxane-polyoxyethylene copolymer, trade name: SH3746, manufactured by Toray Dow Corning Co., Ltd.) 1% by weight (based on the weight of the containing liquid) was added to obtain an inorganic layered compound dispersion (1). 0.1% by weight of nonionic surfactant (polydimethylsiloxane-polyoxyethylene copolymer, trade name: SH3746, manufactured by Toray Dow Corning Co., Ltd.) with respect to this inorganic layered compound dispersion (1) ( (Based on the weight of the dispersion) under low speed stirring (1500 rpm, peripheral speed 4.1 m / min), and then adjusted with an ion exchange resin so that the pH of the system is 3, clay mineral dispersion (1) was prepared. Furthermore, this clay mineral dispersion (1) was treated under the condition of 1100 kgf / cm ² using a high-pressure dispersion device (trade name: Super High-Pressure Homogenizer M110-E / H, manufactured by Microfluidics Corporation), and the coating liquid (1) Got. The cleaved montmorillonite average particle diameter in the coating liquid (1) was 560 nm, the a value obtained from powder X-ray diffraction was 1.2156 nm, and the aspect ratio was 460.

Preparation of coating liquid (2) A clay mineral dispersion (2) was prepared in the same manner as the clay mineral dispersion (1) except that 82 g of high-purity montmorillonite was used.
Furthermore, another dispersion kettle (trade name: Despa MH-L, manufactured by Asada Tekko Co., Ltd.), 1067 g of ion-exchanged water (specific electric conductivity 0.7 μs / cm or less) and polyacrylic acid (Wako Pure Chemical Industries, Ltd.) (Made by Co., Ltd., average molecular weight 100,0000) was mixed with 33 g, and a resin component solution was prepared at room temperature under low speed stirring (1500 rpm, peripheral speed 4.1 m / min).
2519 g of the clay mineral dispersion (2) and 1100 g of the resin component solution are gradually mixed under low speed stirring (1500 rpm, peripheral speed 4.1 m / min) to form a mixed solution, and the mixed solution is further mixed using a high pressure dispersing device. By processing on the conditions of 1100 kgf / cm < ² >, the liquid mixture (2 ') was obtained. The pH of the mixed solution (2 ′) was 6. Thereafter, the mixed solution (2 ′) was adjusted with an ion exchange resin so that the pH was 8 to obtain a coating solution (2). When the total volume of polyvinyl alcohol, polyacrylic acid and the inorganic layered compound in the coating liquid (2) was 100%, the proportion of the inorganic layered compound was 20 vol%.

[Example 1]
A high-density polyethylene sheet (Hi-Zex 1300J; manufactured by Prime Polymer Co., Ltd., 5 cm square, 2 mm thick sheet) is used as a base material layer, and tetramethoxysiloxane as a metal alkoxide on one surface of the base material layer is a hydrocarbon gas. As a propane gas, it was burned and irradiated, and the base material layer was scanned at a speed of 10 m / min to perform a flame treatment to form a surface treatment layer precursor (1). The wetting index on the side where the surface treatment layer precursor (1) was laminated was 64 dyn / cm <. Thereafter, the base material layer on which the surface treatment layer precursor (1) was formed was immersed in isopropyl alcohol for 5 seconds to form the surface treatment layer precursor (2). Thereafter, the base material layer on which the surface treatment layer precursor (2) was formed was further dried to obtain a multilayer structure (1 ′) in which the surface treatment layer was formed on the base material layer. The thickness of the surface treatment layer was 0.1 μm, and the wetting index on the side on which the surface treatment layer was formed was 64 dyn / cm <.
Further, an anchor coating agent (EL510-1 / CAT-RT87 = 5/1 (weight ratio), solid content concentration of 4 wt% is applied on the surface treatment layer of the multilayer structure (1 ′) by a bar coater (# 8). : Toyo Morton Co., Ltd.) was applied and dried at a temperature of 40 ° C. for 1 hour to form an anchor coat layer. The anchor coat layer had a dry thickness of 0.1 μm. A coating liquid (1) was further applied onto the anchor coat layer with a bar coater (# 8) and dried at a temperature of 80 ° C. for 1 hour to provide a film to obtain a multilayer structure (1). . The obtained multilayer structure (1) was subjected to a dry heat treatment, and then further subjected to a drying treatment. Thereafter, the multilayer structure (1) was evaluated. The results are shown in Table 2.

[Example 2]
A multilayer structure (as in Example 1) except that the base material layer on which the surface treatment layer precursor (1) was formed was immersed in acetone for 5 seconds to form the surface treatment layer precursor (2). 2) was obtained. The obtained multilayer structure (2) was subjected to a dry heat treatment and then further subjected to a drying treatment. Thereafter, the multilayer structure (2) was evaluated. The results are shown in Table 2.

[Example 3]
A multilayer structure (3) was obtained in the same manner as in Example 1 except that the coating liquid (2) was used instead of the coating liquid (1). The obtained multilayer structure (3) was subjected to a dry heat treatment, and then further subjected to a dry treatment. Thereafter, the multilayer structure (3) was evaluated. The results are shown in Table 2.

[Example 4]
A multilayer structure (4) was obtained in the same manner as in Example 1 except that a film was provided directly on the surface treatment layer without forming an anchor coat layer. The obtained multilayer structure (4) was subjected to a dry heat treatment, and then further subjected to a drying treatment. Thereafter, the multilayer structure (4) was evaluated. The results are shown in Table 2.

[Comparative Example 1]
A multilayer structure (5) was obtained in the same manner as in Example 1 except that the surface treatment layer precursor (2) was not formed and an anchor coat layer was formed on the surface treatment layer precursor (1). The obtained multilayer structure (5) was subjected to a dry heat treatment, and then further subjected to a drying treatment. Thereafter, the multilayer structure (5) was evaluated. The results are shown in Table 2.

[Comparative Example 2]
A multilayer structure (6) was obtained in the same manner as in Example 1 except that the flame treatment was not performed. The obtained multilayer structure (6) was subjected to a dry heat treatment, and then further subjected to a dry treatment. Thereafter, the multilayer structure (6) was evaluated. The results are shown in Table 2.

[Comparative Example 3]
After forming the surface treatment layer precursor (2), a multilayer structure (7) was obtained in the same manner as in Example 1 except that an anchor coat layer was provided. The obtained multilayer structure (7) was subjected to a dry heat treatment, and then further subjected to a dry treatment. Thereafter, the multilayer structure (7) was evaluated. The results are shown in Table 2.

Table 1

Table 2

Claims (14)

The manufacturing method of the multilayer structure which contains the process of the following (1)-(3) in order.
(1) A flame treatment is performed by bringing a flame in which a mixed gas containing a metal alkoxide and / or an alkyl metal compound and a combustible gas into contact is brought into contact with at least one surface of the substrate layer, and a surface treatment layer precursor ( 1) forming step (2) washing the surface treatment layer precursor (1) with a polar solvent to form the surface treatment layer precursor (2) (3) the surface treatment layer precursor (2) ) Is dried to form a surface treatment layer   The method for producing a multilayer structure according to claim 1, wherein the metal alkoxide and / or the alkyl metal compound contains Si, Ti, Al, or Zr.   The method for producing a multilayer structure according to claim 1 or 2, wherein the base material layer is made of a thermoplastic resin.   The manufacturing method of the multilayer structure in any one of Claims 1-3 whose multilayer structure is a container member. It is the method of joining the container members manufactured by the manufacturing method of Claim 4, and manufacturing a container, Comprising: The manufacturing method of the container which contains the process of the following (1)-(3) in order.
(1) A step of applying a coating liquid containing the polymer component (A) and a liquid medium to at least the inner surface of the container member to form a film. (2) Container members having a film formed on at least the inner surface. (3) The step of dry heat-treating the primary container   The method for producing a container according to claim 5, wherein the polymer component (A) is a polymer component containing a hydroxyl group.   The method for producing a container according to claim 5 or 6, wherein the coating liquid further contains a clay mineral (B). The manufacturing method of the multilayer structure in any one of Claims 1-3 which has the following processes (4) after a process (3).
(4) A step of applying a coating liquid containing the polymer component (A) and a liquid medium on the surface treatment layer to form a film.   The method for producing a multilayer structure according to claim 8, wherein the polymer component (A) is a polymer component containing a hydroxyl group.   The method for producing a multilayer structure according to claim 8 or 9, wherein the coating liquid further contains a clay mineral (B).   The manufacturing method of the multilayer structure in any one of Claims 8-10 whose multilayer structure is a container member. It is the method of joining the container members manufactured by the manufacturing method of Claim 11, and manufacturing a container, Comprising: The manufacturing method of the container which includes the process of the following (1)-(2) in order.
(1) A step of obtaining a primary container by joining container members each having a film formed on at least an inner surface (2) A step of dry heat-treating the primary container   The manufacturing method of the multilayer structure in any one of Claims 8-10 whose multilayer structure is a sheet | seat or a film.   The manufacturing method of a sheet | seat or a film which dry-heat-processes the sheet | seat or film manufactured by the manufacturing method of Claim 13.