Gas barrier coating composition and gas barrier laminate

Abstract

The present invention pertains to a gas-barrier coating composition containing a metal oxide, a phosphoric acid compound, and an amine compound, and a gas-barrier coating film having not only excellent oxygen-barrier properties and moisture-barrier properties, but also excellent transparency; and a gas-barrier laminate including the coating film are provided.

Description

[Technical Field]

[0001] The present invention relates to a gas barrier coating composition containing as constituent components a metal oxide, a phosphate compound, and an amine compound, and more specifically to a coating composition capable of forming a coating film that has excellent oxygen barrier properties and moisture barrier properties as well as excellent transparency, and to a gas barrier laminate containing said coating film. [Background technology]

[0002] BACKGROUND ART Gas barrier laminates have been known which are formed by forming a film containing metal atoms and phosphorus atoms as constituent components on a plastic substrate. For example, Patent Document 1 listed below proposes a substantially continuous and substantially amorphous gas permeation preventive film made of a metal orthophosphate having a metal to phosphorus atomic ratio of about 2.3 to 0.5, 50 to 100% of the metal atoms being aluminum, 0 to 50% of the metal atoms being selected from tin, titanium, and zirconium, and 0 to about 20% of the metal atoms being selected from zinc, chromium, and magnesium.

[0003] However, such gas permeation preventive films have not yet been satisfactory in terms of oxygen barrier property and water vapor barrier property. Furthermore, although it has been shown that resins can be added to improve adhesion to the substrate to be coated, the effect of adding resins in improving the oxygen and water vapor barrier properties of the coating film has not been clarified. To solve these problems, Patent Document 2 listed below describes a composite structure having a substrate (X) and a layer (Y) laminated on the substrate (X), wherein the layer (Y) contains a reaction product (S), and the reaction product (S) is a reaction product obtained by reacting at least a metal oxide (A) with a phosphorus compound (B), and has a viscosity of 800 to 1400 cm -1 The fraction (n) at which the infrared absorption is maximum in the infrared absorption spectrum of the layer (Y) in the range 1 ) is 1080~1130cm -1 and the metal atom (M) constituting the metal oxide (A) is aluminum. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 57-42032 [Patent Document 2] Patent No. 4961054 Summary of the Invention [Problem to be solved by the invention]

[0005] The composite structure disclosed in Patent Document 2 satisfies both the oxygen barrier property and the water vapor barrier property, but since it is mainly made of aluminum, there are concerns about its stability against the acids and alkalis contained in the contents. In order to solve these problems, the present inventors proposed a gas barrier film using a specific zirconium compound (Patent Application No. 2019-152688), but discovered that by further incorporating a specific additive, a coating film with both superior oxygen barrier properties and water vapor barrier properties can be formed in a gas barrier coating composition using a metal oxide and a phosphate compound. Therefore, an object of the present invention is to provide a gas barrier coating composition containing a metal oxide and a phosphate compound, which is capable of forming a gas barrier coating film having superior oxygen barrier properties, water vapor barrier properties and transparency, and a gas barrier laminate comprising this gas barrier coating film (gas barrier layer). [Means for solving the problem]

[0006] According to the present invention, there is provided a gas barrier coating composition containing a metal oxide, a phosphoric acid compound, and an amine compound, wherein the metal oxide is zirconium oxide, and the amine compound is a polyamine compound. Things, A The present invention provides a gas barrier coating composition characterized by containing at least one amino acid compound. In the gas barrier coating composition of the present invention, 1. The amine compound is polyallylamine, polyethyleneimine N, G At least one of lysine and arginine; 2. The phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid; is preferred.

[0007] The present invention also provides a gas barrier laminate comprising a substrate and a coating film made of the gas barrier coating composition. In the gas barrier laminate of the present invention, 1. The coating film has an infrared absorption spectrum of 1000 to 1050 cm -1 The infrared absorption has a maximum absorption peak in the range of 2. The coating film has a maximum peak in the range of 400 to 405 eV in terms of N binding energy measured by XPS. 3. Having an anchor coat layer between the substrate and the coating film; 4. The substrate is made of biaxially oriented polyester with a thickness of 12 μm, and the coating amount on the substrate is 1.0 g / m 2 When the coating film is formed and a 50 μm thick unstretched polypropylene film is placed on the coating film, the oxygen permeability is 25 cc / m 2 ·day·atm (40℃ 90%RH) or less, and the water vapor permeability is 5.5g / m 2 ·day (40℃ 90%RH) or less, is preferred. [Effects of the Invention]

[0008] In the gas barrier coating composition of the present invention, the use of an amine compound together with a metal oxide and a phosphate compound improves the dispersibility of the metal oxide particles, resulting in a smaller particle size. As a result, the metal oxide and the phosphate compound can form a uniform and dense crosslinked structure, making it possible to form a coating film that can exhibit excellent oxygen barrier properties and water vapor barrier properties. Furthermore, the amine compound is also incorporated into the crosslinked structure and functions as a binder between the metal oxide particles, resulting in the formation of a coating film with fewer defects. This, combined with the uniform and dense crosslinked structure described above, allows for the expression of even more excellent oxygen barrier properties and water vapor barrier properties. As a result, the gas barrier coating composition of the present invention can provide a gas barrier laminate that can be used in non-retort applications as well as in retort sterilization. Furthermore, by using zirconium oxide as the metal compound, it is possible to form a coating film that is stable against the acids and alkalis present in the contents, and furthermore, excellent oxygen barrier properties and water vapor barrier properties are exhibited. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a cross-sectional structure of an example of the gas barrier laminate of the present invention. [Figure 2] FIG. 2 is a diagram showing the cross-sectional structure of another example of the gas barrier laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Gas barrier coating composition) An important feature of the gas barrier coating composition of the present invention is that it contains a metal oxide, a phosphoric acid compound and an amine compound. As described above, it has been discovered in the present invention that by containing an amine compound together with a metal oxide and a phosphate compound, it is possible to obtain a coating film with oxygen barrier properties and water vapor barrier properties that are superior to those of a coating film formed from a coating composition consisting of a metal oxide and a phosphate compound.

[0011] [Metal oxides] The metal oxide used in the gas barrier coating composition of the present invention is preferably an oxide of a divalent or higher metal atom, and examples thereof include, but are not limited to, oxides of magnesium, calcium, iron, zinc, aluminum, silicon, titanium, zirconium, etc., and zirconium oxide is particularly preferred. Zirconium oxide contains Zr and O as component elements. Amorphous zirconium oxide contains zirconium hydroxide (Zr(OH)4) and / or zirconyl hydroxide (ZrO(OH)2) as the main component, while crystalline zirconium oxide contains hydrated zirconium oxide (ZrO2·xH2O) and / or zirconium oxide (ZrO2) as the main component. The term "main component" refers to a component that accounts for 50% or more of the zirconium oxide. The crystallinity of zirconium oxide and zirconium oxide gas barrier coatings can be evaluated by identifying the X-ray peaks specific to crystalline zirconium using a conventionally known X-ray structural diffractometer. In the present invention, either crystalline or amorphous zirconium oxide (zirconia) can be used as the zirconium oxide.

[0012] In the aforementioned Japanese Patent Application No. 2019-152688, a prior application by the present inventors, it was preferable to use amorphous zirconium oxide containing many hydroxyl groups that are used in the phosphorylation reaction as the zirconium oxide. However, by incorporating an amine compound, it is possible to form a uniform, dense, and defect-free coating film. Therefore, even when crystalline zirconium oxide is used, it is possible to achieve both oxygen barrier properties and moisture barrier properties equivalent to those achieved when amorphous zirconium is used. Furthermore, it is desirable that the zirconium oxide have an average primary particle size (D50) of 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less, which allows the formation of a uniform coating film with excellent transparency. The average particle size (D50) is the volume-average particle size measured by laser diffraction / scattering, and D50 is the 50% value in the volume-based particle size distribution. Using such fine particle-type zirconium oxide as a raw material allows the development of excellent transparency.

[0013] [Phosphate compounds] Phosphoric acid compounds used in the present invention include orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, and their derivatives. Specific examples of polyphosphoric acid include pyrophosphoric acid, triphosphoric acid, and polyphosphoric acid condensed with four or more phosphoric acids. Examples of the above derivatives include salts, (partial) ester compounds, halides (e.g., chlorides), and dehydrates (e.g., diphosphorus pentoxide) of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid. Examples of phosphonic acid derivatives also include compounds in which the hydrogen atom directly bonded to the phosphorus atom of phosphonic acid (HP(═O)(OH)2) is substituted with an alkyl group that may have various functional groups (e.g., nitrilotris(methylenephosphonic acid), N,N,N′,N′-ethylenediaminetetrakis(methylenephosphonic acid)), as well as salts, (partial) ester compounds, halides, and dehydrates thereof. Furthermore, organic polymers containing phosphorus atoms, such as phosphorylated starch, can also be used. These phosphate compounds can be used alone or in combination of two or more. In the present invention, it is particularly preferable to use at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

[0014] [Amine compounds] As the amine compound used in the present invention, conventionally known amine compounds such as monoamines, polyamines, polyamine compounds, amino sugar compounds, and amino acid compounds can be used. Examples of monoamines include, but are not limited to, primary amines such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, valerylamine, isovalerylamine, cyclohexylamine, benzylamine, and allylamine; secondary amines such as dimethylamine, methylethylamine, diethylamine, methylpropylamine, methylisopropylamine, ethylpropylamine, methylbutylamine, ethylbutylamine, di-n-propylamine, and diallylamine; and tertiary amines such as trimethylamine, triethylamine, dimethylethylamine, diethylmethylamine, and diisopropylethylamine.

[0015] Examples of polyamines include, but are not limited to, ethylenediamine, 1,2-propanediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, bis(dimethylamino)methane, N,N-dimethylethylenediamine, N,N'-dimethylethylenediamine, N-ethylethylenediamine, N-methyl-1,3-propanediamine, 1,3-diaminopentane, N-isopropylethylenediamine, N-isopropyl-1,3-propanediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyltrimethylenediamine, N,N,N',N'-tetramethyl-1,2-propanediamine, N,N,2,2-tetramethyl-1,3-propanediamine, N,N,N',N'-tetramethyl Examples of the amines include diamines such as diethyl tetramethylenediamine, N,N-dimethyl-1,6-diaminohexane, N,N,N',N'-tetramethyl-2,2-dimethyl-1,3-propanediamine, and N,N,N',N'-tetramethylhexamethylenediamine; and polyamines having three or more amino groups in the molecule, such as diethylenetriamine, bis(3-aminopropyl)amine, N-(3-aminopropyl)-1,3-propanediamine, 3,3'-diamino-N-methyldipropylamine, spermidine, N,N,N',N',N''-pentamethyldiethylenetriamine, 3,3'-iminobis(N,N-dimethylpropylamine), bis(hexamethylene)triamine, triethylenetriamine, N,N'-bis(3-aminopropyl)ethylenediamine, and tetraethylenepentamine.

[0016] Examples of polyamine compounds include polyalkyleneimine, polydiallylamine, polyallylamine, polyvinylamine, polyethyleneimine, etc. The weight average molecular weight of the polyamine compound is preferably in the range of 1,600 to 25,000. Examples of amino sugar compounds include monosaccharides such as glucosamine, galactosamine, and mannosamine, and polysaccharides such as chitin and chitosan. Examples of amino acid compounds include α-amino acids such as glycine, alanine, serine, tryptophan, glutamine, and arginine, β-amino acids such as β-alanine, γ-amino acids such as γ-aminobutyric acid, and amino acid polymers. In the present invention, it is particularly preferable to use at least one of polyallylamine, polyethyleneimine, chitosan, glycine, and arginine.

[0017] [Preparation of Composition] The gas barrier coating composition of the present invention may be either an aqueous or solvent-based composition as long as it contains the above-mentioned metal oxide, phosphate compound and amine compound, but is preferably an aqueous composition. In the gas barrier coating composition, it is desirable to use a sol containing metal oxide fine particles as the dispersoid as the metal oxide. Furthermore, although not essential in the present invention using an amine compound, a sol containing metal oxide fine particles as a dispersoid can be dispersed in the presence of a deflocculating agent to produce a dispersion with excellent transparency and viscosity stability. Examples of such deflocculating agents include nitric acid, hydrochloric acid, perchloric acid, formic acid, acetic acid, citric acid, malic acid, and lactic acid, and among these, dispersions using acetic acid, hydrochloric acid, nitric acid, and citric acid are particularly preferred. The use of such a dispersion facilitates uniform dispersion of the metal oxide in the gas barrier coating composition or the gas barrier coating film formed from this coating composition. When nitric acid (concentration = 1 mol / L) is used as the deflocculating agent (concentration = 1 mol / L), it is preferably added in an amount of 0.01 to 30 g, particularly 2.68 to 5.36 g, per 21.9 g of sol containing zirconium oxide sol as a dispersoid.

[0018] Next, the phosphoric acid compound, the amine compound and the zirconium oxide are mixed in a solvent capable of dissolving the phosphoric acid compound and the amine compound. As such an aqueous medium, conventionally known aqueous media such as distilled water, ion-exchanged water, and pure water can be used. Similar to known aqueous compositions, organic solvents such as alcohols, polyhydric alcohols, and their derivatives can be contained. When such a cosolvent is used, it can be contained in an amount of 1 to 90 wt % relative to the resin components in the aqueous composition. By including a solvent in the above range, film-forming performance is improved. Preferred organic solvents are those having amphiphilic properties, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, methyl ethyl ketone, butyl cellosolve, propylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, and 3-methyl-3-methoxybutanol.

[0019] In the gas barrier coating composition of the present invention, the phosphate compound and amine compound can be added in an amount that does not impair the oxygen barrier property and water vapor barrier property. The phosphate compound is preferably blended so that the net intensity ratio P(P-kα) / M(M-kα) of the metal oxide and the phosphate compound, as measured by fluorescent X-rays, is in the range of 0.5 to 10. When zirconium oxide is used as the metal oxide, it is preferably blended so that the net intensity ratio P(P-kα) / Zr(Zr-kα), as measured by fluorescent X-rays, is in the range of 2.8 to 8.0, particularly 2.8 to 7.1. Furthermore, in the gas barrier coating composition, the amount of amine compound added varies depending on the type of amine compound used, but it is preferable to add it in an amount of 0.1 to 100 parts by mass, particularly 1.0 to 40 parts by mass, per 100 parts by mass of metal oxide. If the amount added is less than the above range, the effect obtained by adding the amine compound will not be as sufficient as when it is within the above range, and if the amount added is greater than the above range, not only will no further effect be obtained, but there is also a risk of defects in the barrier structure of the coating film compared to when it is within the above range. In addition to the above components, the gas barrier coating composition may also contain crosslinking agents, metal complexes, polymeric compounds, fillers, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, colorants, etc.

[0020] (Gas barrier coating) The gas barrier coating film formed from the gas barrier coating composition of the present invention comprises the metal oxide, phosphoric acid compound and amine compound described above, and specifically, a phosphate ester bond is formed, crosslinking the metal oxide and the phosphoric acid compound, and the amine compound reacts with the metal ion and phosphoric acid to form an ammonium salt compound, which is incorporated into the crosslinked structure, forming a composite structure. Therefore, the coating film made of the gas barrier coating composition of the present invention has a spectral response of 800 to 1400 cm by FT-IR measurement of the coating film alone. -1 In the infrared absorption spectrum in the range of 1000-1050 cm -1 The gas barrier coating film has a maximum infrared absorption peak in the range of 400 to 405 eV, and also has a maximum peak in the nitrogen (N) binding energy range (400 to 405 eV) when measured by X-ray photoelectron spectroscopy (XPS) of the gas barrier coating film alone.

[0021] Furthermore, a coating film made from the gas barrier coating composition of the present invention preferably has a net intensity ratio P(P-kα) / M(M-kα) of 0.5 to 10, or 2.8 to 8.0, particularly 2.8 to 7.1, when the metal oxide is zirconium oxide, as determined by fluorescent X-ray analysis. Having a net intensity ratio P(P-kα) / M(M-kα) within this range allows the phosphate compound to react efficiently with the hydroxyl groups of the metal oxide in the coating film, neither too much nor too little, to form a uniform and dense coating film, which can exhibit excellent oxygen and water vapor barrier properties. Specifically, if the net intensity ratio determined by fluorescent X-ray analysis is below this range and the amount of phosphate compound is insufficient, bonding between metal atomic particles will be insufficient, and the amount of hydroxyl groups present on the surfaces of the metal atomic particles will increase, potentially resulting in reduced oxygen and water vapor barrier properties. On the other hand, if the net intensity ratio measured by fluorescent X-ray measurement is greater than the above range and the amount of phosphate compound is excessive, the amount of hydroxyl groups derived from phosphate groups will increase, which may also result in a decrease in oxygen barrier property and water vapor barrier property.

[0022] (Gas barrier laminate) The gas barrier laminate of the present invention is a laminate comprising a substrate and a gas barrier layer comprising the gas barrier coating film described above formed on at least one surface thereof, and preferably, as shown in Figure 1, a gas barrier layer 3 is formed on substrate 1 via an anchor coat layer 2 described below. The anchor coat layer 2 is a coating film that has excellent adhesion to plastic substrate 1, and by forming the gas barrier layer on this coating film, the interlayer adhesion between the gas barrier layer and the plastic substrate is significantly improved, and peeling of the gas barrier layer from the substrate can be effectively prevented even when subjected to retort sterilization. In the gas barrier laminate of the present invention, it is preferable to form a moisture-resistant resin layer 4 made of a thermoplastic resin such as an unstretched polypropylene resin film on the gas barrier layer 3, as shown in FIG.

[0023] The gas barrier laminate of the present invention has a gas barrier layer itself that has sufficient gas barrier properties, particularly oxygen barrier properties and water vapor barrier properties, and is made of a 12 μm thick biaxially oriented polyester substrate film, a coating amount of 1.0 g / m 2 In the case of a gas barrier coating film coated with a 50 μm thick unstretched polypropylene film, the oxygen permeability (based on JIS K-7126) is 25 cc / m 2 ·day·atm (40℃ 90%RH) or less, and the water vapor permeability is 5.5g / m 2 It has excellent oxygen barrier properties and retort resistance, with a storage temperature of 40°C / 90%RH or less. Furthermore, the gas barrier laminate having the above structure has excellent transparency, with a total light transmittance of 85% or more and a haze of 30% or less.

[0024] [Base material] The substrate for the gas barrier laminate may be a conventionally known substrate made of a resin such as a thermoplastic resin or a thermosetting resin, or a fiber such as paper or nonwoven fabric, but preferred examples include any packaging material in the form of a film, sheet, bottle, cup, tray, can, or the like, produced from a thermoformable thermoplastic resin by means of extrusion molding, injection molding, blow molding, stretch blow molding, press molding, or the like.

[0025] Examples of thermoplastic resins that can be used for the substrate include olefin copolymers such as low-, medium-, or high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ionomer, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate, and polyethylene naphthalate; polyamides such as nylon 6, nylon 6,6, nylon 6,10, and metaxylylene adipamide; styrene copolymers such as polystyrene, styrene-butadiene block copolymer, styrene-acrylonitrile copolymer, and styrene-butadiene-acrylonitrile copolymer (ABS resin); vinyl chloride copolymers such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymer; acrylic copolymers such as polymethyl methacrylate and methyl methacrylate-ethyl acrylate copolymer; and polycarbonate. In the present invention, a sheet made of polyethylene terephthalate, polybutylene terephthalate or polypropylene can be particularly suitably used.

[0026] These thermoplastic resins may be used alone or in the form of a blend of two or more kinds, or different resins may be present in the form of a laminate. The plastic substrate may have a single layer structure or a laminate structure of two or more layers formed by, for example, simultaneous melt extrusion or other lamination. If desired, one or more additives such as pigments, antioxidants, antistatic agents, UV absorbers, and lubricants may be added to the melt-moldable thermoplastic resin in a total amount of 0.001 to 5.0 parts per 100 parts by mass of the resin. Furthermore, for example, in order to reinforce this container, one or more of the following fiber reinforcing materials may be blended in a total amount of 2 to 150 parts by mass per 100 parts by mass of the thermoplastic resin: glass fiber, aromatic polyamide fiber, carbon fiber, pulp, cotton linter, etc.; powder reinforcing materials: carbon black, white carbon, etc.; or flake-like reinforcing materials: glass flakes, aluminum flakes, etc.; and for the purpose of further increasing the weight, one or more of heavy or soft calcium carbonate, mica, talc, kaolin, gypsum, clay, barium sulfate, alumina powder, silica powder, magnesium carbonate, etc. may be blended in a total amount of 5 to 100 parts by mass per 100 parts by mass of the thermoplastic resin according to a formulation known per se. Furthermore, for the purpose of improving gas barrier properties, scaly inorganic fine powders such as water-swellable mica, clay, etc. may be blended in a total amount of 5 to 100 parts by mass per 100 parts by mass of the thermoplastic resin according to a known formulation. Similarly, for the purpose of improving the gas barrier properties, there is no problem in providing a thin film layer of an inorganic material such as silicon oxide or aluminum oxide on a plastic substrate by physical or chemical vapor deposition.

[0027] The substrate may be a final film, sheet, or molded article such as a container, or the like, or the coating may be provided in advance on a preform for molding into a container. Examples of such preforms include cylindrical parisons with or without bottoms for biaxially stretched blow molding, pipes for plastic can molding, sheets for vacuum forming, pressure forming, and plug-assist molding, or films for heat-sealed lids and bags.

[0028] [Anchor coat layer] As the anchor coat layer formed on the surface of the substrate as required, a conventionally known anchor coat layer made of a polyurethane resin composed of a polyol and an isocyanate compound, which is used in gas barrier laminates, can be used, but the anchor coat layer proposed by the present inventors and made of a polyurethane resin and a silane coupling agent is preferred.

[0029] <Polyurethane resin> The polyurethane resin constituting the anchor coat layer can be any known polyurethane resin that has been conventionally used for anchor coat layers, but in the present invention, it is desirable to use one having a glass transition temperature (Tg) of 80° C. or higher, particularly in the range of 80 to 120° C. If the glass transition temperature is lower than the above range, the heat resistance of the anchor coat layer will be inferior compared to when the glass transition temperature is within the above range, and if a difference in shrinkage rate due to heating occurs between the anchor coat layer and the gas barrier layer, cracks may occur in the gas barrier layer, resulting in a decrease in barrier properties.

[0030] Examples of the polyol component that is the main component of the polyurethane resin include glycol, polyester polyol, polyether polyol, acrylic polyol, and urethane-modified versions of these, with glycol being particularly preferred. The glass transition temperature of the polyester polyol is preferably −50° C. to 100° C., more preferably −20° C. to 80° C. The number average molecular weight of these polyester polyols is preferably 500,000 to 100,000, more preferably 500,000 to 80,000. Examples of glycols include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, and 1,6-hexanediol. Examples of polycarboxylic acids include aromatic polycarboxylic acids such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid, and aliphatic polycarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and cyclohexanedicarboxylic acid.

[0031] As the isocyanate component which is a curing agent for polyurethane resins, aromatic diisocyanates, alicyclic diisocyanates, aliphatic diisocyanates, etc. can be used. Examples of aromatic diisocyanates include tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or a mixture thereof) (TDI), phenylene diisocyanate (m-, p-phenylene diisocyanate or a mixture thereof), 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (NDI), diphenylmethane diisocyanate (4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof) (MDI), 4,4'-toluidine diisocyanate (TODI), and 4,4'-diphenyl ether diisocyanate. Examples of aromatic aliphatic diisocyanates include xylene diisocyanate (1,3- or 1,4-xylene diisocyanate or a mixture thereof) (XDI), tetramethyl xylene diisocyanate (1,3- or 1,4-tetramethyl xylene diisocyanate or a mixture thereof) (TMXDI), and ω,ω'-diisocyanato-1,4-diethylbenzene.

[0032] Examples of alicyclic diisocyanates include 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), methylene bis(cyclohexyl isocyanate) (4,4'-, 2,4'-, or 2,2'-methylene bis(cyclohexyl isocyanate)) (hydrogenated MDI), methyl cyclohexane diisocyanate (methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate), bis(isocyanatomethyl)cyclohexane (1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof) (hydrogenated XDI), and the like.

[0033] Examples of aliphatic diisocyanates include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caffeate.

[0034] The polyisocyanate component may be a polyfunctional polyisocyanate compound such as isocyanurate, biuret, or allophanate derived from the above polyisocyanate monomer, or a polyfunctional polyisocyanate compound having a terminal isocyanate group obtained by reaction with a trifunctional or higher polyol compound such as trimethylolpropane or glycerin. The polyisocyanate component preferably has a glass transition temperature (Tg) of 50° C. or higher and a number average molecular weight (Mn) of 400 or higher, and more preferably has a glass transition temperature (Tg) of 60° C. or higher and a number average molecular weight (Mn) of 500 or higher. In the present invention, it is preferable to use xylene diisocyanate among the above isocyanate components.

[0035] <Silane coupling agent> As the silane coupling agent used in the anchor coat layer, an epoxy silane coupling agent can be suitably used. Examples of such epoxy silane coupling agents that can be used include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropyltrimethoxysilane. Other silane coupling agents include tetramethoxysilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-isocyanatepropyltriethoxysilane, and can be used as needed. Furthermore, for the purpose of improving hot water resistance adhesion, the silane coupling agent used may be hydrolyzed as necessary to promote a condensation reaction of the silane coupling agent.

[0036] [Anchor coat layer forming composition] In the present invention, the anchor coat layer-forming composition preferably contains the above-mentioned polyurethane resin and silane coupling agent. The anchor coat layer-forming composition may be either water-based or solvent-based, but is preferably an aqueous composition, and therefore the polyurethane resin used is preferably a water-soluble or water-dispersible polyurethane. In the anchor coat layer-forming composition, the epoxy silane compound is preferably contained in an amount of 1 to 60 parts by mass per 100 parts by mass (solid content) of the polyurethane resin. If the epoxy silane compound is less than the above range, the crack resistance when dried cannot be satisfied compared to when it is within the above range. On the other hand, if the epoxy silane compound is more than the above range, it is difficult to further improve adhesion, and there is a risk that hot water resistance may be impaired.

[0037] The aqueous medium may contain the same conventionally known aqueous medium as that used in the gas barrier layer-forming composition, as well as organic solvents such as alcohols, polyhydric alcohols, and derivatives thereof. In addition to the above components, the anchor coat layer-forming composition may also contain known curing-accelerating catalysts, fillers, softeners, antioxidants, stabilizers, adhesion promoters, leveling agents, antifoaming agents, plasticizers, inorganic fillers, tackifying resins, fibers, colorants such as pigments, usable time extenders, etc.

[0038] (Method of manufacturing gas barrier laminate) In the method for producing the gas barrier laminate of the present invention, the gas barrier coating composition of the present invention can be applied directly to at least one surface of the above-mentioned substrate, but it is preferable to apply the above-mentioned anchor coat layer-forming composition prior to applying the gas barrier coating composition. The coating amount of the anchor coat layer-forming composition is determined by the content of the polyurethane resin and silane coupling agent in the composition, and cannot be generally defined, but is generally in the range of 0.05 to 1.00 g / m2 in terms of the solid weight of the coating film. 2 , especially 0.10 to 0.50 g / m 2 If the anchor coat coating weight is less than the above range, the anchor coat layer may not be able to be fixed to the substrate as well as when it is within the above range, while if the anchor coat coating weight is more than the above range, it becomes less economical. The anchor coat layer-forming composition applied to the substrate is dried at a temperature of 80 to 140°C for 1 to 60 seconds to remove the solvent from the composition, depending on the composition and coating amount used. This allows the anchor coat layer to be formed economically without affecting the substrate, even if it is made of a plastic with a low melting point, such as polypropylene.

[0039] Next, a gas barrier coating composition is applied onto the dry anchor coat layer-forming composition from which the solvent has been removed. The coating amount of the gas barrier coating composition is determined by the contents of the metal oxide, phosphoric acid compound, and amine compound in the composition and cannot be generally defined, but is generally 0.05 to 2.0 g / m2 in terms of the solid weight of the coating film. 2 , especially 0.3 to 1.5 g / m 2 It is preferable to coat the film so that the coating amount falls within the above range. If the coating amount is less than the above range, sufficient barrier properties cannot be obtained. On the other hand, if the coating amount is more than the above range, it is only inferior in economic efficiency and does not offer any particular advantage. The gas barrier coating composition is then heated at a temperature of 80°C to 220°C, particularly 140°C to 220°C, for 1 second to 10 minutes, depending on the composition and coating amount of the metal oxide, phosphate compound, and amine compound in the composition used, to form a gas barrier layer. This reduces the difference in shrinkage due to heating between the gas barrier layer and the anchor coat layer, making it possible to improve the crack resistance of the gas barrier layer, and also significantly improves the interlayer adhesion between the gas barrier layer and the anchor coat layer, preventing peeling of the gas barrier layer from the substrate even when subjected to retort sterilization.

[0040] The application of the anchor coat layer forming composition and the gas barrier coating composition and the drying or heat treatment can be carried out by a conventionally known method. The application method is not limited to these, but for example, spray coating, immersion, or application with a bar coater, roll coater, gravure coater, or the like is possible. The drying or heating treatment can be carried out by oven drying (heating), infrared heating, high frequency heating, or the like. [Example]

[0041] The present invention will be further explained by the following examples, but the present invention is not limited to these examples. Various measurement and evaluation methods in the examples and comparative examples are as follows.

[0042] Example 1 Zirconium oxide sol (Zirconia sol ZSL-10T, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., amorphous zirconium oxide, solid content (ZrO2 equivalent) = 10%) was used as the metal oxide, and a water / methanol solvent was used to prepare a solution with a solid content of 3.3% and a water / methanol ratio of 65 / 35. Next, 5.36 g of nitric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 1 mol / L) as a deflocculating agent was added to 21.9 g of the above zirconium oxide sol (solid content (ZrO2 equivalent) = 10%), 7.5 phr of polyallylamine (manufactured by Nittobo Medical Co., Ltd., PAA-25, concentration = 10%, weight average molecular weight MW = 25,000) as an amine compound was added to the solid content (ZrO2 equivalent) of the above zirconium oxide sol, and 85% phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 85%) as a phosphate compound was added to the solid content (ZrO2 equivalent) of the above zirconium oxide sol so that the non-volatile content of the phosphoric acid was 136 phr, and the mixture was stirred for a predetermined time to obtain a gas barrier coating composition.

[0043] (Method for producing a gas barrier laminate sample) The gas barrier laminate samples were prepared using the prepared gas barrier coating composition as follows: The gas barrier coating composition was applied in an amount of 1.0 g / m2 using a bar coater onto a substrate of 12 μm thick biaxially stretched polyester film (Lumirror P60, manufactured by Toray Advanced Film Co., Ltd.). 2 The coating was then heated and dried in a box oven at 220°C for 10 minutes to obtain a sample of a gas barrier laminate.

[0044] (Method for preparing laminate samples for evaluating gas barrier properties) The laminate sample for evaluating gas barrier properties was coated with a gas barrier coating composition on the surface of the gas barrier laminate at a coating amount of 4.0 g / m 2 A urethane adhesive (Takenate A-315 / Takenate A-50, manufactured by Mitsui Chemicals, Inc.) was applied using a bar coater, dried using a dryer, and then a 50 μm thick unstretched polypropylene film (Toray Processing Film Co., Ltd., Torayfan ZK401) was laminated to produce the gas barrier laminate shown in Example 1.

[0045] Example 2 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 7.5 phr of polyallylamine (PAA-01, manufactured by Nittobo Medical Co., Ltd., concentration = 10%, weight average molecular weight MW = 1,600) was blended as the amine compound in the gas barrier coating composition.

[0046] Example 3 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 110 phr of non-volatile phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was blended as the phosphate compound in the gas barrier coating composition. Example 4

[0047] In Example 1, a gas barrier laminate and a gas barrier laminate film were obtained in the same manner as in Example 1, except that 120 phr of non-volatile phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was blended as the phosphate compound in the gas barrier coating composition.

[0048] Example 5 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 123 phr of non-volatile phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was blended as the phosphate compound in the gas barrier coating composition.

[0049] Example 6 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 140 phr of non-volatile phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was blended as the phosphate compound in the gas barrier coating composition.

[0050] Example 7 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 15 phr of polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd., weight average molecular weight MW=10,000) prepared as a 10% aqueous solution was blended as the amine compound of the gas barrier coating composition.

[0051] Example 8 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 15 phr of glycine (manufactured by Wako Pure Chemical Industries, Ltd.) prepared as a 10% aqueous solution was added as the amine compound in the gas barrier coating composition.

[0052] Example 9 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 15 phr of D-arginine (manufactured by Wako Pure Chemical Industries, Ltd.) prepared as a 10% aqueous solution was blended as the amine compound in the gas barrier coating composition.

[0053] Example 10 In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 15 phr of L-arginine (manufactured by Wako Pure Chemical Industries, Ltd.) prepared as a 10% aqueous solution was added as the amine compound in the gas barrier coating composition.

[0054] Example 11 A gas barrier laminate and a laminate for evaluating gas barrier properties were obtained in the same manner as in Example 1, except that the deflocculating agent for the gas barrier coating composition was not added.

[0055] Example 12 Zirconium oxide sol (Daiichi Kigenso Kagaku Kogyo Co., Ltd., Zirconia Sol ZSL-00120A, crystalline zirconium oxide, solids content (ZrO2 equivalent) = 30%) was used as the metal oxide, and a water / methanol solvent was used to prepare a 3.0% solids solution with a water / methanol ratio of 65 / 35. Next, polyallylamine (Nittobo Medical Co., Ltd., PAA-25, concentration = 10%, weight average molecular weight MW = 25,000) was added as an amine compound at 7.5 phr relative to the solids content (ZrO2 equivalent) of the zirconium oxide sol, and phosphoric acid (Wako Pure Chemical Industries, Ltd., concentration = 85%) was added as a phosphate compound at a non-volatile content of 58 phr relative to the solids content (ZrO2 equivalent) of the zirconium oxide sol. The mixture was stirred for a predetermined period of time to prepare a gas barrier coating composition. Gas barrier laminates and laminates for gas barrier evaluation were obtained in the same manner as in Example 1.

[0056] (Comparative Example 1) In Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 2.68 g of nitric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 1 mol / L) was used as a deflocculating agent for the gas barrier coating composition relative to 21.9 g of zirconium oxide sol (solid content (ZrO2 equivalent) = 10%), and no amine compound was added.

[0057] (Comparative Example 2) In Comparative Example 1, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 1, except that 159 phr of non-volatile phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 85%) was blended as the phosphate compound in the gas barrier coating composition.

[0058] (Comparative Example 3) In Example 12, a gas barrier laminate and a laminate for gas barrier evaluation were obtained in the same manner as in Example 12, except that 5.36 g of nitric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 1 mol / L) was used as a deflocculating agent for the gas barrier coating composition relative to 21.9 g of zirconium oxide sol (solid content (ZrO2 equivalent) = 10%), no amine compound was added, and 97 phr of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 85%) was added as the phosphate compound.

[0059] (Reference example 1) A laminate for evaluating gas barrier properties was obtained in the same manner as in Example 1, except that in Example 1, the gas barrier coating composition was not applied and a 12 μm thick biaxially oriented polyester film (Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) was used as the substrate.

[0060] (Evaluation method) The evaluation results of the gas barrier laminate and the laminate for gas barrier evaluation were obtained using the following evaluation methods, as shown in Table 1.

[0061] [Oxygen permeability] The gas barrier property evaluation laminates obtained in the Examples, Comparative Examples, and Reference Examples were measured using an oxygen permeability measuring device (OX-TRAN2 / 21, manufactured by Modern Control) under the following measurement conditions: temperature 40°C, relative humidity 90%.

[0062] [Water vapor permeability] The gas barrier property evaluation laminates obtained in the Examples, Comparative Examples, and Reference Examples were measured using a water vapor transmission rate measuring device (PERMATRAN-W 3 / 31, manufactured by Modern Control) under the conditions of a temperature of 40°C and a relative humidity of 90%.

[0063] [Optical properties] For each of the gas barrier laminates obtained in the Examples, Comparative Examples, and Reference Examples, the total light transmittance (TT:%) and haze (Hz:%) were measured using a color computer (SM-4, manufactured by Suga Test Instruments Co., Ltd.) with the polyester film substrate side as the incident light side for measurement.

[0064] [Infrared absorption spectrum] For each gas barrier laminate obtained in the examples and comparative examples, the infrared absorption spectrum of the gas barrier coating film applied on the polyester substrate was measured using a Fourier transform infrared spectrophotometer (FT / IR-6600, manufactured by JASCO Corporation). [Measurement conditions of FT-IR apparatus] Equipment used: FT / IR-6600 manufactured by JASCO Measurement conditions: Method ATR (Ge prism) Detector MCT Attachment Thunder Dome Wavenumber range 800 - 1400 cm -1 Film measurement surface: Barrier coating film surface

[0065] [Fluorescent X-ray evaluation] As an evaluation method for the elements contained in each gas barrier laminate obtained in the examples and comparative examples, for phosphorus and zirconium elements, they can be quantified by a commercially available fluorescent X-ray analyzer. The net intensity obtained from the measurement of each gas barrier laminate is taken as P / Zr for P and Zr, and the content ratio of the metal elements in the coating film is calculated and used for evaluation. [Measurement conditions of fluorescent X-ray analyzer] Equipment used: ZSX100e manufactured by Rigaku Measurement conditions: Measurement targets Zr-Kα line, P-Kα line Measurement diameter 10 mm Measured X-ray Rh (4.0 kw) 50 kv 72 mA (2θ = 0 - 90) Film measurement surface: X-rays are incident from the barrier coating film surface side for measurement ​​​​As a method for evaluating the chemical bonding state of elements contained in each gas barrier laminate obtained in the examples and comparative examples, by irradiating X-rays onto the sample surface and measuring the energy of the generated photoelectrons, the constituent elements of the sample and their electronic states can be analyzed. For nitrogen and zirconium elements, analysis was performed using a commercially available X-ray photoelectron spectrometer. The binding energy of the elements obtained from the measurement of each gas barrier laminate was analyzed with the peak position of Zr3d 5 / 2 set to 185.0, and the bonding state of nitrogen elements in the coating film was evaluated. The numerical value of Zr3d 5 / 2 used for peak correction was referenced from the literature J. inorg. nucl. Chem. Vol.43, No.12, pp.3329-3334, 1981. <Measurement Conditions of X-ray Photoelectron Spectrometer> Equipment Used: Manufactured by Thermo Fisher SCIENTIFIC K-ALPHA Measurement Conditions: Measured elements Zr3d, N1s Peak Correction Zr3d 5 / 2 : 185.0 X-ray Type: Al Monochromator Ion Gun Ion Energy 6,000 eV Ar Gas Cluster Cluster Size: Small Etch Phases Number of Levels 50<00,00369>Time per Level (s) 30<o000371>Pass Energy 150.0 eV Measurement Diameter 400 μm Film Measurement Surface: Barrier Coating Film Surface

[0067] The various measurement and evaluation results of the above examples, comparative examples, and reference examples are shown in Table 1.

[0068]

Table 1

[0069] [Abbreviations in Table 1] ZSL-10T: amorphous zirconium oxide, ZSL-00120A: crystalline zirconium oxide, HNO3: nitric acid, PAA: polyallylamine, PEI: polyethyleneimine, Gly: glycine, Arg: arginine, TT: total light transmittance, Hz: haze, P / Zr: content ratio of phosphorus element (P) derived from phosphate compounds in the coating film to zirconium element (Zr) in the metal oxide

[0070] In Table 1, "-" means "not added," "not performed," "not detected," etc. [Industrial Applicability]

[0071] The gas barrier coating composition of the present invention is capable of forming a coating film with excellent oxygen barrier properties and water vapor barrier properties, and can be suitably used as a transparent high-barrier packaging material. [Explanation of symbols]

[0072] 1 substrate, 2 anchor coat layer, 3 gas barrier layer (gas barrier film), 4 moisture-resistant resin layer

Claims

1. A gas barrier coating composition containing a metal oxide, a phosphoric acid compound, and an amine compound, wherein the metal oxide is zirconium oxide, and the amine compound is at least one of a polyamine compound and an amino acid compound.

2. 2. The gas barrier coating composition according to claim 1, wherein the amine compound is at least one of polyallylamine, polyethyleneimine, glycine, and arginine.

3. 3. The gas barrier coating composition according to claim 1, wherein the phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

4. A gas barrier laminate comprising a substrate and a coating film made of the gas barrier coating composition according to any one of claims 1 to 3.

5. The coating film has an infrared absorption spectrum of 1000 to 1050 cm －１ 5. The gas barrier laminate according to claim 4, which has a maximum infrared absorption peak in the range of 1000 to 15000.

6. 6. The gas barrier laminate according to claim 4, wherein the coating film has a maximum peak in the range of 400 to 405 eV in terms of N bond energy measured by XPS.

7. 7. The gas barrier laminate according to claim 4, further comprising an anchor coat layer between the substrate and the coating film.

8. The substrate is made of biaxially oriented polyester having a thickness of 12 μm, and the coating amount on the substrate is 1.0 g / m ２ When the coating film is formed and a 50 μm thick unstretched polypropylene film is placed on the coating film, the oxygen permeability is 25 cc / m ２ day·atm (40°C 90% RH) or less, and the water vapor permeability is 5.5 g / m ２ The gas barrier laminate according to any one of claims 4 to 7, wherein the gas barrier laminate has a temperature of 40°C, 90% RH or less.

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