Gas barrier laminate

Abstract

To provide a gas barrier laminate suppressed in generation of crack even when a gas barrier layer is formed under high temperature, free from generating interlayer peeling even when subjected to retort sterilization, and excellent in oxygen barrier and water vapor barrier.SOLUTION: In a gas barrier laminate having an anchor coat layer on at least one surface of a base material, and a gas barrier layer containing at least a metal oxide formed on the anchor coat layer is formed, the anchor coat layer is formed of a hydrophilic group-containing resin and an epoxy-based silane coupling agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a gas barrier laminate having an anchor coat layer and a gas barrier layer formed on a substrate, and more specifically to a gas barrier laminate having excellent oxygen barrier properties and water vapor barrier properties, in which crack formation in the gas barrier layer is suppressed and delamination does not occur even when subjected to retort sterilization. [Background technology]

[0002] Gas barrier laminates, which consist of a gas barrier layer containing a metal oxide formed on a plastic substrate, have been proposed in various forms as having excellent oxygen barrier and water vapor barrier properties. For example, Patent Document 1 below describes a composite structure having a base material (X) and a layer (Y) laminated on the base material (X), wherein the layer (Y) contains a reaction product (S), and the reaction product (S) is a reaction product formed by the reaction of at least a metal oxide (A) and a phosphorus compound (B), and is 800-1400 cm -1 In the infrared absorption spectrum of the layer (Y) within the range, the fractional part (n) at which infrared absorption is maximized is... 1 ) is 1080~1130cm -1 A multilayer composite has been proposed in which, within the range, the metal atoms (M) constituting the metal oxide (A) are aluminum, the composite structure has an anchor coat layer made of a polyurethane resin and a silane coupling agent on at least one surface of the substrate, and a gas barrier layer containing at least a metal oxide is provided on the anchor coat layer.

[0003] However, the multilayer structure described in Patent Document 1 requires a curing reaction of the isocyanate component when forming layer (Y) on layer (Z), and thus requires a curing process, making it difficult to continuously form a gas barrier layer. Furthermore, because high-temperature heating is required to form layer (Y), a difference in shrinkage rate occurs between layer (Y) and layer (Z), which may cause cracks to occur in the gas barrier layer (Y).

[0004] To solve these problems, the present inventors have proposed a gas barrier laminate characterized by having an anchor coat layer made of a polyurethane resin and a silane coupling agent on at least one surface of a substrate, and having a gas barrier layer containing at least a metal oxide on the anchor coat layer (Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-1574 [Patent Document 2] Japanese Patent Publication No. 2020-151854 [Overview of the initiative] [Problems that the invention aims to solve]

[0006] The gas barrier laminate described in Patent Document 2 above exhibits strong adhesion of the gas barrier layer to the substrate, and excellent adhesion to the substrate can be expected even when subjected to retort sterilization. However, obtaining an excellent barrier layer requires sufficient crosslinking of the barrier layer, which necessitates high-temperature drying. However, high-temperature drying can sometimes cause cracks in the barrier layer. When such cracked barrier layers are subjected to retort sterilization, delamination occurs, making it difficult to fully exhibit the desired oxygen gas barrier and water vapor barrier properties.

[0007] Accordingly, the object of the present invention is to provide a gas barrier laminate in which an anchor coat layer and a gas barrier layer are formed on a substrate, wherein crack formation is suppressed even when the gas barrier layer is formed at high temperature, and interlayer delamination does not occur even when subjected to retort sterilization, and the gas barrier laminate exhibits excellent oxygen barrier properties and water vapor barrier properties. [Means for solving the problem]

[0008] According to the present invention, in a gas barrier laminate having an anchor coat layer on at least one surface of a base material, and a gas barrier layer containing at least a metal oxide formed on the anchor coat layer, the anchor coat layer is composed of a hydrophilic group-containing resin and an epoxy-based silane coupling agent, and the hydrophilic group-containing resin is a carboxyl group-containing polyester resin. Furthermore, the epoxy-based silane coupling agent is blended in an amount greater than 100 parts by mass and less than 400 parts by mass per 100 parts by mass of the hydrophilic group-containing resin. There is provided a gas barrier laminate characterized by this.

[0009] In the gas barrier laminate of the present invention, ( 1 ) the epoxy-based silane coupling agent is 3-glycidyloxypropyltrimethoxysilane; ( 2 ) the carboxyl group-containing polyester resin has a glass transition temperature of 67°C or higher; ( 3 ) the carboxyl group-containing polyester resin is an amorphous polyester; ( 4 ) the 3-glycidyloxypropyltrimethoxysilane is blended in an amount of 150 to 300 parts by mass with respect to 100 parts by mass of the polyester resin solid content; ( 5 ) the value obtained by dividing the detected amount of Si (Si-kα) in the fluorescent X-ray measurement of the anchor coat layer by the coating amount is in the range of 1.6 to 3.1; ( 6 ) the gas barrier layer is composed of a reaction product of a metal oxide and a phosphate compound; ( 7 ) the gas barrier layer is composed of a reaction product of a metal oxide, a phosphate compound, and an amine compound; ( 8 ) the gas barrier layer is composed of a reaction product of a metal oxide, a phosphate compound, and a carboxylate of a polyvalent metal soluble in phosphoric acid; ( 9 ) the metal oxide is zirconium oxide; ( 10The phosphate compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid. ( 11 ) The carboxylate of the polyvalent metal consists of an amine compound containing a polyvalent metal ion and an organic carboxylic acid. ( 12 ) The polyvalent metal ion is an aluminum ion, and the amine compound is an amino acid. ( 13 ) The carboxylate of the polyvalent metal is aluminum glycinate. ( 14 ) The gas barrier layer has an absorption peak with the maximum infrared absorption in the range of 1000 to 1130 cm -1 in the infrared absorption spectrum. ( 15 ) The gas barrier layer has a peak with the maximum N binding energy by XPS in the range of 400 to 405 eV. ( 16 ) In the case where the base material is made of a 12-μm-thick biaxially stretched polyester film, the anchor coat layer is formed on the base material with a film thickness of 0.01 to 10.0 g / m 2 and the gas barrier layer is formed on the anchor coat layer with a film thickness of 0.10 to 5.0 g / m 2 and the gas barrier laminate is provided with a 50-μm-thick unstretched polypropylene film via an adhesive, the oxygen transmission rate is 10 cc / m 2 ·day·atm (40 °C, 90% RH) or less, and the water vapor transmission rate is 5.5 g / m 2 ·day (40 °C, 90% RH) or less. 2 ·day (40 °C, 90% RH) or less. ( 17 ) In the gas barrier laminate where the base material is made of a 12-μm-thick biaxially stretched polyester film, the anchor coat layer is formed on the base material with a film thickness of 0.01 to 10.0 g / m 2 and the gas barrier layer is formed on the anchor coat layer with a film thickness of 0.10 to 5.0 g / m<00, the total light transmittance is 85% or more, and the haze is 30% or less. 2 is preferable. is suitable.

[0010] The present invention also provides a container characterized by having a laminated structure of the above-mentioned gas barrier laminate. The present invention further provides an anchor coat layer forming composition for forming an anchor coat layer on a substrate, wherein the composition contains an epoxy silane coupling agent in an amount greater than 100 parts by mass and less than 400 parts by mass per 100 parts by mass of a water-soluble polyester resin and / or a water-dispersible polyester resin (solids). [Effects of the Invention]

[0011] In the gas barrier laminate of the present invention, the anchor coat layer consists of a hydrophilic group-containing resin such as a carboxyl group-containing polyester resin and an epoxy-based silane coupling agent, which significantly improves the adhesion between the substrate and the gas barrier layer. Furthermore, since no cracks occur even when the gas barrier layer is formed at a high temperature of 220°C, delamination is effectively suppressed even when subjected to retort sterilization, and the laminate exhibits excellent oxygen barrier and water vapor barrier properties. Furthermore, because the gas barrier layer is formed with metal oxides and phosphate compounds together with amine compounds or carboxylates of polyvalent metals soluble in phosphoric acid, a uniform and dense crosslinked structure can be formed by the metal oxides and phosphate compounds. Combined with the presence of the aforementioned anchor coat layer, this significantly improves oxygen barrier properties and water vapor barrier properties when subjected to retort sterilization. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a cross-sectional structure of an example of the gas barrier laminate of the present invention. [Figure 2] This figure shows a cross-sectional structure of another example of the gas barrier laminate of the present invention. [Modes for carrying out the invention]

[0013] (Anchor coat layer) An important feature of the gas barrier laminate of the present invention is that the anchor coat layer consists of a hydrophilic group-containing resin and an epoxy-based silane coupling agent.

[0014] [Hydrophilic group-containing resin] The hydrophilic group-containing resin that constitutes the anchor coat layer is a resin that contains carboxyl groups, hydroxyl groups, amino groups, or their derivatives or metal salts within its molecule. By including these hydrophilic groups within the molecule, it is possible to exist in a state that is dispersible in water, and these hydrophilic groups react with epoxy silane coupling agents to improve the hardness, heat resistance, chemical resistance, flexibility, adhesion, etc. of the coating film. Examples of such hydrophilic group-containing resins include, but are not limited to, water-dispersible or water-soluble polyester resins, water-dispersible or water-soluble acrylic resins, water-dispersible or water-soluble polyurethane resins, etc. However, in the present invention, polyester resins are preferred, and among them, carboxyl group-containing polyester resins can be preferably used.

[0015] Carboxyl group-containing polyester resins can be prepared by combining monomer components commonly used in the polymerization of polyester resins with carboxylic acid anhydrides such as phthalic anhydride, succinic anhydride, maleic anhydride, trimellitic anhydride, itaconic anhydride, and citraconic anhydride. Examples of such monomer components include, as polycarboxylic acid components, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedionic acid, and dimer acid; unsaturated dicarboxylic acids such as (anhydride) maleic acid, fumaric acid, and terpene-maleic acid adducts; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydroisophthalic acid, and 1,2-cyclohexenedicarboxylic acid; and polycarboxylic acids of trivalent or higher carboxylic acids such as (anhydride) trimellitic acid, (anhydride) pyromellitic acid, and methylcyclohexentricarboxylic acid. One or more of these can be selected and used. In the present invention, from the viewpoint of heat resistance and other factors, it is preferable that the proportion of aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid in the polycarboxylic acid components constituting the polyester resin is 50 mol% or more.

[0016] Furthermore, there are no particular limitations on the polyhydric alcohol components that make up the polyester resin, including ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1-methyl-1,8-octanediol, 3-methyl-1,6-hexanediol, 4-methyl-1,7-heptanediol, and 4-methyl One or more of the following polyhydric alcohol components can be used: aliphatic glycols such as -1,8-octanediol, 4-propyl-1,8-octanediol, and 1,9-nonanediol; ether glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alicyclic polyalcohols such as 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, tricyclodecane glycols, and hydrolyzed bisphenols; and trihydric or higher polyalcohols such as trimethylolpropane, trimethylolethane, and pentaerythritol. In the present invention, among the above polyhydric alcohol components, ethylene glycol, propylene glycol, and neopentyl glycol can be preferably used.

[0017] Carboxyl group-containing polyester resins can be produced by known methods, such as polycondensation of one or more of the above-mentioned polycarboxylic acid components with one or more of the polyhydric alcohol components; depolymerization after polycondensation with a polycarboxylic acid component, such as terephthalic acid, isophthalic acid, trimellitic anhydride, trimellitic acid, pyromellitic acid, etc.; or ring-opening addition of an acid anhydride, such as phthalic anhydride, maleic anhydride, trimellitic anhydride, ethylene glycol bistrimellitate dianhydride, etc., after polycondensation.

[0018] The carboxyl group-containing polyester resin preferably has an acid value in the range of 1 to 80 KOH mg / g, particularly 10 to 30 KOH mg / g. If the acid value is lower than the above range, there will be fewer carboxyl groups that can react with the epoxy silane coupling agent compared to when it is within the above range, which may result in the inability to obtain the desired hardness of the coating film and lead to inferior heat resistance and chemical resistance. In addition, the amount of uncrosslinked components will increase, which may reduce the water resistance and retort resistance of the coating film. On the other hand, if the acid value is higher than the above range, there will be more reaction sites with the epoxy silane coupling agent compared to when it is within the above range, which will result in superior curability of the coating film, but may lead to inferior flexibility of the coating film and a decrease in the flexibility of the gas barrier laminate. Furthermore, there will be more free carboxyl groups that are not used in the reaction, which may reduce water resistance.

[0019] For carboxyl group-containing polyester resins, a glass transition temperature (Tg) in the range of 0 to 120°C, particularly 67 to 80°C, is preferable from the viewpoint of crack resistance. If the Tg is lower than the above range, it may become more difficult to suppress crack formation compared to when it is within the above range. On the other hand, if the Tg is higher than the above range, the formed coating film becomes harder, which may reduce the flexibility of the gas barrier laminate. The carboxyl group-containing polyester resin used may be a blended polyester resin, as long as the acid value and Tg after blending fall within the above range. Furthermore, the carboxyl group-containing polyester resin is preferably an amorphous polyester.

[0020] [Epoxy-based silane coupling agent] In the present invention, by using a silane coupling agent containing epoxy groups that can react with hydrophilic groups such as carboxyl groups and hydroxyl groups of the hydrophilic group-containing resin, the hardness, heat resistance, chemical resistance, flexibility, and adhesiveness of the resulting anchor coat layer are improved. Conventional epoxy silane coupling agents can be used, including 3-glycidyloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and triethoxy(3-glycidyloxypropyl)silane, with 3-glycidyloxypropyltrimethoxysilane being particularly preferred. Furthermore, for the epoxy-based silane coupling agent used, hydrolysis may be performed as needed to advance the condensation reaction of the silane coupling agent, in order to improve its resistance to hot water adhesion.

[0021] [Composition for forming an anchor coat layer] In the present invention, the composition for forming the anchor coat layer is preferably prepared as an aqueous composition comprising the above-mentioned hydrophilic group-containing resin, in particular a carboxyl group-containing polyester resin, and an epoxy-based silane coupling agent. The epoxy silane coupling agent is preferably blended in an amount greater than 100 parts by mass but less than 400 parts by mass, particularly 150 to 300 parts by mass, per 100 parts by mass of carboxyl group-containing polyester resin (solids). If the amount of epoxy silane coupling agent is less than the above range, the crack resistance performance during drying is inferior to that when it is within the above range. On the other hand, even if the amount of epoxy silane coupling agent is greater than the above range, it is difficult to further improve adhesion, and there is a risk that the resistance to hot water will be impaired.

[0022] Furthermore, conventionally known aqueous media such as distilled water, deionized water, and pure water can be used as the aqueous medium, and like known aqueous compositions, organic solvents such as alcohols, polyhydric alcohols, and their derivatives can be contained. When such co-solvents are used, they can be contained in an amount of 5 to 99% by weight relative to the resin content in the aqueous composition. Including the solvent within the above range improves the film-forming performance. As such organic solvents, those having amphiphilic properties are preferred, and examples include 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. In addition to the above components, the composition for forming the anchor coat layer may also contain known curing accelerators, fillers, softeners, antioxidants, stabilizers, adhesion promoters, leveling agents, defoamers, plasticizers, inorganic fillers, tackifying resins, fibers, colorants such as pigments, and extenders of usable time.

[0023] The anchor coat layer preferably has a value obtained by dividing the amount of Si(Si-kα) detected by X-ray fluorescence measurement by the amount of the composition for forming the anchor coat layer, which is in the range of 1.6 to 3.1, particularly 2.2 to 2.7. When the amount of Si(Si-kα) detected by X-ray fluorescence measurement is within the above range, there is an adequate amount of silane coupling agent in the anchor coat layer, which reacts efficiently with the hydrophilic group-containing resin to form a uniform and dense coating film, ensuring excellent crack resistance and retort resistance. If the amount of Si(Si-kα) detected by X-ray fluorescence measurement is lower than the above range, and there is insufficient silane coupling agent, the bonding between the hydrophilic group-containing resin and the epoxy-based silane coupling agent will be insufficient, and improvement in crack resistance cannot be expected compared to when the value is within the above range. In addition, there will be a large amount of free hydrophilic groups that are not used in the reaction, which may reduce water resistance. On the other hand, if the amount detected by X-ray fluorescence measurement is greater than the above range, and there is an excess of epoxy-based silane coupling agent, the resistance to hot water may decrease compared to when it is within the above range.

[0024] (Gas barrier layer) The gas barrier layer formed on the anchor coat layer formed by the above-described anchor coat layer forming composition preferably contains at least a metal oxide, and more preferably a phosphoric acid compound. Furthermore, the gas barrier layer preferably contains an amine compound or a carboxylate of a polyvalent metal soluble in phosphoric acid, along with the metal oxide and phosphoric acid compound.

[0025] [Metal oxides] The metal oxide is preferably an oxide of a metal atom with a valence of 2 or higher, but is not limited to this. Examples include oxides of magnesium, calcium, iron, zinc, aluminum, silicon, titanium, and zirconium, with zirconium oxide being particularly suitable. Zirconium oxides contain Zr and O as constituent elements. Amorphous zirconium oxides mainly contain zirconium hydroxide (Zr(OH)4) and / or zirconium hydroxide (ZrO(OH)2), while crystalline zirconium oxides mainly contain hydrated zirconium oxide (ZrO2·xH2O) and / or zirconium oxide (ZrO2). Note that "main component" refers to a component present in a proportion of 50% or more. The crystallinity of zirconium oxides and zirconium oxides coated with gas barriers can be evaluated by identifying the X-ray peaks characteristic of crystalline zirconium using a conventionally known X-ray structural diffractometer. In this invention, either crystalline or amorphous zirconium oxide (zirconia) can be used.

[0026] Generally, zirconium oxide is used in the form of a sol containing zirconium oxide particles as a dispersed phase and an inorganic acid such as nitric acid as a stabilizer. However, in the present invention, in order to prevent the volatilization of the acid during film formation due to the presence of inorganic acid, it is preferable to use a zirconium oxide sol in which carbonates, ammonium carbonates, or organic dispersants are used instead of inorganic acids such as nitric acid. Furthermore, it is desirable that the zirconium oxide has an average particle size (D50) of primary particles of 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less, which allows for 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. By using such fine particle type zirconium oxide as a raw material, excellent transparency can be achieved.

[0027] [Phosphate compounds] Examples of phosphate compounds 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 formed by the condensation of four or more phosphoric acids. Examples of the above derivatives include salts, (partial) ester compounds, halides (such as chlorides), and dehydrated products (such as phosphorus pentoxide) of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid salts. 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 replaced by an alkyl group that may have various functional groups (e.g., nitrilotris (methylenephosphonic acid), N,N,N',N'-ethylenediaminetetrakis (methylenephosphonic acid), etc.), as well as their salts, (partial) ester compounds, halides, and dehydrated products. Furthermore, organic polymers containing phosphorus atoms, such as phosphorylated starch, can also be used. These phosphate compounds can be used individually or in combination of two or more. In the present invention, it is particularly preferable to use at least one of orthophosphate, metaphosphate, polyphosphate, and cyclic polyphosphate.

[0028] [Amine compounds] In the gas barrier layer of the present invention, it is preferable that an amine compound is further included along with the metal oxide and phosphoric acid compound, and that the layer is composed of reaction products thereof. The amine compounds used in the present invention can be conventionally known amine compounds such as monoamines, polyhydric amines, polyamine compounds, amino sugar compounds, and amino acid compounds, but polyamine compounds, amino acid compounds, and amino sugar compounds can be preferably used. Examples of polyamine compounds include polyalkyleneimines, polydiallylamines, polyallylamines, polyvinylamines, and polyethyleneimines. 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, as well as polysaccharides such as chitin and chitosan. Examples of amino acid compounds include α-amino acids such as glycine, alanine, serine, tryptophan, glutamine, lysine, and arginine; β-amino acids such as β-alanine; γ-aminobutyric acid 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, lysine, and arginine.

[0029] [Carboxylates of polyvalent metals soluble in phosphoric acid] In the gas barrier layer of the present invention, it is preferable that the layer contains, along with the above-mentioned metal oxide and phosphoric acid compound, a carboxylate salt of a polyvalent metal soluble in phosphoric acid (hereinafter sometimes simply referred to as "polyvalent metal carboxylate salt"), and is composed of reaction products thereof. Such polyvalent metal carboxylates can preferably consist of polyvalent metal ions and amine compounds containing organic carboxylic acids. The polyvalent metal ions eluted from the polyvalent metal carboxylate dissolved by phosphoric acid can compensate for the lack of metal ions in the binder between particles in the cross-linked structure between the metal oxide and phosphoric acid, thereby further improving the oxygen gas barrier properties and water vapor barrier properties. The polyvalent metal ions in polyvalent metal carboxylates are not particularly limited as long as they provide polyvalent metal ions that can crosslink the carboxyl group. Examples of polyvalent metal ions include alkaline earth metals (magnesium Mg, calcium Ca, strontium Sr, barium Ba, etc.), Group 8 metals of the periodic table (iron Fe, ruthenium Ru, etc.), Group 11 metals of the periodic table (copper Cu, etc.), Group 12 metals of the periodic table (zinc Zn, etc.), and Group 13 metals of the periodic table (aluminum Al, etc.), but they are particularly preferably divalent to trivalent, and aluminum ions can be used. Furthermore, the above metal ions can be used individually or in combination of two or more.

[0030] Examples of amine compounds containing organic carboxylic acids that can form polyvalent metal ions and polyvalent metal carboxylate salts include amino acid compounds having an amino group and a carboxyl group. Examples of amino acid compounds include α-amino acids such as glycine, alanine, serine, tryptophan, lysine, arginine, glutamic acid, and aspartic acid, β-amino acids such as β-alanine, γ-aminobutyric acid such as γ-aminobutyric acid, and amino acid polymers. One or more of these can be used in combination, and glycine and aspartic acid can be used particularly favorably. In the present invention, aluminum glycinate can be particularly suitably used as the carboxylate of a polyvalent metal.

[0031] [Gas barrier coating composition] The gas barrier coating composition of the present invention may be either an aqueous or solvent-based composition, provided that it contains the above-mentioned metal oxide and phosphoric acid compound, and preferably further contains an amine compound or a polyvalent metal carboxylate. However, an aqueous composition is preferred. In gas barrier coating compositions, it is preferable to use a sol in which metal oxide fine particles are dispersed as the metal oxide. As mentioned above, in the present invention, it is preferable to use a sol in which metal oxide fine particles are dispersed that does not contain an inorganic acid as a stabilizer. For similar reasons, it is desirable that the gas barrier coating composition of the present invention does not use volatile and corrosive inorganic acids such as nitric acid, hydrochloric acid, and acetic acid as deglutinating agents, which were previously used to improve the dispersibility of metal oxide fine particles and to create a dispersion with excellent transparency and viscosity stability.

[0032] Next, the phosphoric acid compound, the amine compound or polyvalent metal carboxylate (as needed), and the metal zirconium oxide are mixed in a solvent in which they can be dissolved. Such aqueous media can be conventionally known aqueous media such as distilled water, deionized water, or pure water, and, like known aqueous compositions, can contain organic solvents such as alcohols, polyhydric alcohols, their derivatives, or ketones. When such co-solvents are used, they can be contained in an amount of 1 to 90% by weight relative to the resin content in the aqueous composition. Including a solvent within the above range improves film-forming performance. Such organic solvents are preferably amphiphilic, and examples include 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, 3-methyl 3-methoxybutanol, and acetone.

[0033] Furthermore, in the present invention, a generally known dispersion treatment can be used to prepare the coating for forming a gas barrier laminate. Known dispersion treatment methods include pulverization of fine particles by cavitation using an ultrasonic homogenizer, mechanical dispersion using a disperser with rotating blades, and dispersion using a mill with glass or zirconia beads. In the present invention, these fine dispersion treatments for coatings can be used.

[0034] In the gas barrier coating composition of the present invention, phosphoric acid compounds and polyvalent metal carboxylates can be added within a range that does not impair oxygen barrier properties and water vapor barrier properties. The phosphate compound is preferably formulated such that the net intensity ratio P(P-kα) / M(M-kα) of the carboxylate salt of the metal oxide or polyvalent metal and the phosphate compound, as measured by X-ray fluorescence, is in the range of 0.5 to 20. When zirconium oxide is used as the metal oxide, it is preferable to formulate it so that the net intensity ratio P(P-kα) / Zr(Zr-kα) of the zirconium oxide and the phosphate compound, as measured by X-ray fluorescence, is in the range of 1.0 to 8.0, particularly in the range of 2.0 to 7.0. When aluminum salt is used as the carboxylate salt of the polyvalent metal, it is preferable to formulate it so that the net intensity ratio P(P-kα) / Al(Al-kα) of the aluminum salt and the phosphate compound, as measured by X-ray fluorescence, is in the range of 0.1 to 12.0, particularly in the range of 3.0 to 8.0.

[0035] In a 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. Similarly, the amount of polyvalent metal carboxylate added also varies depending on the type of polyvalent metal carboxylate used and cannot be specified in general terms, but it is preferable to add it in an amount of 1 to 300 parts by mass, particularly 5 to 50 parts by mass, per 100 parts by mass of metal oxide. If the amount of amine compound or polyvalent metal carboxylate added is less than the above range, the effects obtained by adding them will not be as sufficient as when they are within the above range, and even if the amount added is greater than the above range, not only will no further effects be obtained, but there is also a risk of defects occurring in the gas barrier structure of the coating film compared to when it is within the above range. In addition to the above components, gas barrier coating compositions may also contain crosslinking agents, metal complexes, polymer compounds, fillers, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, colorants, and the like.

[0036] (Gas barrier coating) In the gas barrier laminate of the present invention, the gas barrier layer consists of the aforementioned metal oxide, phosphoric acid compound, and preferably an amine compound or polyvalent metal carboxylate. Specifically, a phosphate ester bond is formed, and the metal oxide and phosphoric acid compound are crosslinked, thereby enabling the formation of a dense crosslinked structure. Furthermore, when the amine compound or polyvalent metal carboxylate contains an amine compound that includes an organic carboxylic acid, it reacts with the metal ion and phosphoric acid to form an ammonium salt compound which is incorporated into the above crosslinked structure, or the amine compounds condense together to form a polyamide, thus forming a composite structure. Therefore, the gas barrier layer of the gas barrier laminate of the present invention has a FT-IR measurement of 800 to 1400 cm² for the coating film alone. -1 In the infrared absorption spectrum in the range of 1000-1130 cm -1 It is characterized by having an absorption peak with maximum infrared absorption in the range, and also by having a maximum peak in the range of nitrogen (N) binding energy (400-405 eV) as measured by X-ray photoelectron spectroscopy (XPS) of the gas barrier coating film alone. For polyamides, FT-IR measured 1650 cm². -1 The formation can be confirmed by the infrared absorption wavelength.

[0037] Furthermore, in the gas barrier laminate of the present invention, the net intensity ratio P(P-kα) / M(M-kα) of the metal oxide or polyvalent metal carboxylate and the phosphoric acid compound, as measured by X-ray fluorescence, is preferably in the range of 0.5 to 20, 1.0 to 8.0, particularly 2.0 to 7.0, when the metal oxide is zirconium oxide, and 0.1 to 12.0, particularly 3.0 to 8.0, when the polyvalent metal carboxylate is aluminum salt. By having the net intensity ratio P(P-kα) / M(M-kα) within the above range, the phosphoric acid compound reacts efficiently and without excess or deficiency with the hydroxyl groups of the metal oxide in the coating film, making it possible to form a uniform and dense coating film, and enabling the expression of excellent oxygen barrier properties and water vapor barrier properties. In other words, if the net intensity ratio measured by X-ray fluorescence is lower than the above range, indicating a deficiency of phosphate compounds, the bonding between metal atomic particles will be insufficient, and the amount of hydroxyl groups present on the surface of the metal atomic particles will increase, potentially reducing oxygen barrier properties and water vapor barrier properties. On the other hand, if the net intensity ratio measured by X-ray fluorescence is higher than the above range, indicating an excess of phosphate compounds, the amount of hydroxyl groups derived from phosphate groups will increase, also potentially reducing oxygen barrier properties and water vapor barrier properties.

[0038] (Gas barrier laminate) As shown in Figure 1, the gas barrier laminate of the present invention has an anchor coat layer 2 formed on at least one surface of a substrate 1, consisting of a hydrophilic group-containing resin and an epoxy-based silane coupling agent, and a gas barrier layer 3 containing at least a metal oxide is formed on this anchor coat layer 2. The anchor coat layer 2 has excellent adhesion to the plastic substrate 1 and, as mentioned above, is a coating film with excellent crack resistance. Because a gas barrier layer is formed on top of this anchor coat layer, the occurrence of cracks during drying can be effectively prevented, and the interlayer adhesion between the gas barrier layer and the plastic substrate is significantly improved. This effectively prevents the gas barrier layer from peeling off the substrate even when subjected to retort sterilization. Furthermore, in the gas barrier laminate of the present invention, as shown in Figure 2, it is preferable to form a heat-sealable resin layer 4 made of a thermoplastic resin such as an unstretched polypropylene resin film on top of the gas barrier layer 3.

[0039] The gas barrier laminate of the present invention is a base film made of biaxially oriented polyester with a thickness of 12 μm, and a coating amount of 0.01 to 10.0 g / m². 2 The aforementioned anchor coat layer, coating amount 0.10~5.0 g / m 2 In the case where the product comprises the aforementioned gas barrier layer and an unoriented polypropylene film with a thickness of 50 μm via an adhesive, the oxygen permeability (according to JIS K-7126) is 10 cc / m² regardless of whether or not retort treatment is performed. 2 The humidity level is below day·atm (40℃ 90%RH), and the water vapor transmission rate is 5.5 g / m³. 2 It possesses excellent oxygen barrier and water vapor barrier properties, with a temperature of 40°C and 90% RH below day. Furthermore, the gas barrier laminate with the above configuration also exhibits excellent transparency, with a total light transmittance of 85% or more and a haze of 30% or less.

[0040] [Base material] As the substrate for the gas barrier laminate, conventionally known substrates consisting of resins such as thermoplastic resins and thermosetting resins, or fibers such as paper and nonwoven fabrics can be used. Preferably, examples include films, sheets, or any packaging material such as bottles, cups, trays, or cans, manufactured from thermoformable thermoplastic resins by means of extrusion molding, injection molding, blow molding, stretch blow molding, or press molding.

[0041] Examples of thermoplastic resins constituting the base material 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, sheets made of polyethylene terephthalate, polybutylene terephthalate, or polypropylene can be suitably used.

[0042] These thermoplastic resins may be used individually, as a blend of two or more, or as laminates of different resins. The plastic substrate may be a single layer or a laminate of two or more layers, for example, by co-melt extrusion or other lamination processes. The aforementioned melt-mold thermoplastic resin may optionally contain one or more additives such as pigments, antioxidants, antistatic agents, ultraviolet absorbers, and lubricants, in a total amount of 0.001 to 5.0 parts by mass per 100 parts by mass of the resin. Furthermore, for example, to reinforce this container, one or more types of fiber reinforcing materials such as glass fibers, aromatic polyamide fibers, carbon fibers, pulp, cotton linters, powder reinforcing materials such as carbon black, white carbon, or flake-shaped reinforcing materials such as glass flakes, aluminum flakes may be added in a total amount of 2 to 150 parts by mass per 100 parts by mass of the thermoplastic resin. Additionally, for the purpose of increasing the volume, one or more types of heavy to soft calcium carbonate, mica, talc, kaolin, gypsum, clay, barium sulfate, alumina powder, silica powder, magnesium carbonate, etc. may be added in a total amount of 5 to 100 parts by mass per 100 parts by mass of the thermoplastic resin, according to known formulations. Furthermore, for the purpose of improving gas barrier properties, flaky inorganic fine powders, such as water-swellable mica or clay, may be added in a total amount of 5 to 100 parts by mass per 100 parts by mass of the thermoplastic resin, in accordance with known formulations. Similarly, for the purpose of improving gas barrier properties, there is no problem in providing a thin film layer of inorganic materials, such as silicon dioxide or aluminum oxide, on a plastic substrate using physical or chemical vapor deposition.

[0043] The base material may be a final film, sheet, or molded product such as a container, or this coating may be pre-applied to a pre-molded product for forming a container. Examples of such pre-molded products include bottomed or bottomless cylindrical parisons for biaxial stretch blow molding, pipes for plastic can molding, sheets for vacuum forming, pressure forming, plug-assisted molding, or heat-sealable lids, films for bag making, etc.

[0044] (Method for manufacturing gas barrier laminates) In the method for producing the gas barrier laminate of the present invention, the aforementioned anchor coat layer forming composition is first applied to at least one surface of the substrate described above. The amount of anchor coat layer-forming composition to be applied is determined by the content of hydrophilic group-containing resin and epoxy-based silane coupling agent in the composition and cannot be specified in general terms, but is generally between 0.01 and 10.0 g / m² in terms of the solid content weight of the coating film. 2 Especially 0.10~9.0g / m 2 It is preferable to apply the anchor coat within the specified range. If the amount of anchor coat applied is less than the specified range, the anchor coat layer may not adhere to the substrate as well as when it is within the specified range. On the other hand, if the amount of anchor coat applied is more than the specified range, it will be 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, depending on the composition and application amount, to remove the solvent from the composition. This allows for the economical formation of an anchor coat layer without affecting the substrate, even if it is made of a low-melting-point plastic such as polypropylene.

[0045] Next, the gas barrier layer-forming composition is applied to the anchor coat layer-forming composition, which has been desoldered and is now dry. The amount of gas barrier layer-forming composition to be applied is determined by the content of metal oxides and phosphoric acid compounds in the composition and cannot be specified in general terms, but is generally between 0.10 and 5.0 g / m² in terms of the solid content weight of the coating film. 2 Especially 0.50~2.5g / m 2 It is preferable to apply the coating within the specified range. If the coating amount is less than the specified range, sufficient gas barrier properties cannot be obtained. On the other hand, applying more than the specified range is only economically disadvantageous and offers no particular advantages. Next, the gas barrier layer-forming composition is heated at a temperature of 80 to 220°C, particularly 140 to 220°C, for 1 second to 10 minutes, depending on the composition and amount of metal oxide 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, and, combined with the use of an anchor coat layer with excellent crack resistance, improves the crack resistance of the gas barrier layer. Furthermore, the interlayer adhesion between the gas barrier layer and the anchor coat layer is significantly improved, preventing the gas barrier layer from peeling off the substrate even when subjected to retort sterilization. Moreover, because high-temperature heating is possible, the curability of the gas barrier layer can be improved, and the oxygen barrier and water vapor barrier properties can be maintained without deterioration after retort sterilization.

[0046] The application, drying, or heat treatment of the above-mentioned anchor coat layer forming composition and gas barrier layer forming composition can be carried out by conventionally known methods. The application method is not limited to this, but can be, for example, spray painting, dipping, or by bar coater, roll coater, gravure coater, etc. Furthermore, drying or heat treatment can be carried out by methods such as oven drying with hot air, infrared heating, or high-frequency heating.

[0047] (container) An important feature of the container of the present invention is that it has a laminated structure of the gas barrier laminate described above, that is, a layer configuration in which the aforementioned anchor coat layer is located on at least one surface of the substrate, and a gas barrier layer is formed on the anchor coat layer. Examples of such containers, though not limited to these, include the following: For example, a pouch made by creating a laminated film or sheet using a film or sheet as a base material, on which an anchor coat layer and a gas barrier layer are formed, and on which a heat-sealable resin layer is further formed, and then stacking these laminated films or sheets so that the heat-sealable resin layer faces each other; a container made by using a molded product having the shape of a cup, tray or bottle as a base material, on which an anchor coat layer and a gas barrier layer are formed on its surface; or a container obtained by vacuum forming, pressure forming, plug-assisted molding, etc., of the above-mentioned laminated sheet. [Examples]

[0048] The present invention will be further described by the following examples, but the present invention is not limited in any way by these examples. The various measurement and evaluation methods for the examples and comparative examples are as follows.

[0049] (Example 1) [Preparation of compositions for forming anchor coat layers and gas barrier coating compositions] As a composition for forming an anchor coat layer (hereinafter referred to as "anchor coat paint"), a polyester resin emulsion solution (KA3556, solids content = 30%, Tg = 80°C, manufactured by Unitika) was used and diluted with water. Then, 3-glycidyloxypropyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a silane coupling agent in an amount of 150 parts by mass per 100 parts by mass of solids content of the polyester resin emulsion, and the mixture was stirred for a predetermined time to obtain the anchor coat paint. Next, as the gas barrier coating composition (hereinafter referred to as "barrier coat coating"), zirconium oxide sol (Zirconia sol ZSL-00120B, manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd., crystalline zirconium oxide, tetragonal system, solid content (in ZrO2 equivalent) = 20%)) was used as the metal oxide. First, the zirconium oxide sol was diluted by adding water and isopropanol. Next, for 100 parts by mass of the solid content of the zirconium oxide sol, water, phosphoric acid (concentration = 75%, manufactured by Wako Pure Chemical Industries) (52 parts by mass of the non-volatile content of the phosphoric acid), and aluminum glycinate (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed as an additive solution to prepare the solution. Finally, the additive solution was added to the diluted zirconium oxide sol solution and stirred for a predetermined time. A barrier coat coating was obtained in which the coating solid content was 12% and the ratio of water to isopropanol was 80 / 20.

[0050] [Method for preparing gas barrier laminate samples] Samples of gas barrier laminates were prepared using the fabricated anchor coat and barrier coat coatings as follows: A 12 μm thick plastic substrate (Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) was coated with the aforementioned anchor coat coating at a rate of 0.14 g / m² using a bar coater. 2 The coating was applied in this manner and then heated and dried in a box oven at 140°C for 1 minute. After that, the aforementioned barrier coat paint was applied using a bar coater at a rate of 1.98 g / m². 2 The material was coated and heated and dried in a box oven at 220°C for 10 minutes to obtain a sample of a gas barrier laminate.

[0051] [Method for preparing samples for evaluation of gas barrier properties, etc.] The sample used for evaluating gas barrier properties, etc. (hereinafter referred to as the "evaluation sample") was applied to the barrier coating surface of the aforementioned gas barrier laminate at a rate of 4.0 g / m². 2A sample for gas barrier property evaluation was obtained by applying a urethane-based adhesive (Takenate A-315 / Takenate A-50, manufactured by Mitsui Chemicals) with a bar coater, drying it with a dryer, and then laminating it with a 50 μm thick unoriented polypropylene film (Toray Film Processing Co., Ltd., Torayfan ZK401).

[0052] (Example 2) In Example 1, 175 parts by mass of 3-glycidyloxypropyltrimethoxysilane was added as a silane coupling agent to the anchor coat paint, and the application amount was 0.16 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0053] (Example 3) In Example 1, 200 parts by mass of 3-glycidyloxypropyltrimethoxysilane was added as a silane coupling agent to the anchor coat paint, and the application amount was 0.28 g / m². 2 The amount of barrier coat paint applied should be 2.11 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0054] (Example 4) In Example 1, 250 parts by mass of 3-glycidyloxypropyltrimethoxysilane was added as a silane coupling agent to the anchor coat paint, and the application amount was 0.21 g / m². 2 The amount of barrier coat paint applied should be 2.11 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0055] (Example 5) In Example 1, a polyester resin emulsion solution (KA5034, solids content = 30%, Tg = 67°C, manufactured by Unitika) was used as the anchor coat coating, and 300 parts by mass of 3-glycidyloxypropyltrimethoxysilane was added as a silane coupling agent, with a coating amount of 5.65 g / m². 2The amount of barrier coat paint applied should be 2.14 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0056] (Example 6) In Example 1, 250 parts by mass of 3-glycidyloxypropyltrimethoxysilane was added as a silane coupling agent to the anchor coat paint, and the application amount was 8.74 g / m². 2 This means that the amount of barrier coat paint applied should be 2.02 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0057] (Comparative Example 1) In Example 1, a gas barrier laminate and evaluation samples were obtained using the same method as in Example 1, except that no anchor coat paint was applied and a 12 μm thick biaxially oriented polyester film (Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) was used as the base material.

[0058] (Comparative Example 2) In Example 1, 3-glycidyloxypropyltrimethoxysilane was not added to the anchor coat paint, and the application amount was 0.15 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0059] (Comparative Example 3) In Example 1, the curing agent of the anchor coat paint was changed to 3-aminopropyltriethoxysilane, the amount added was 250 parts by mass, and the application amount was 0.18 g / m². 2 Except for the above, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1.

[0060] (Comparative Example 4) As the anchor coat coating, a polyester resin emulsion solution (KA3556, solids content = 30%, Tg = 80°C, manufactured by Unitika) was used and diluted with water. Then, tetraethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a silane coupling agent in an amount of 250 parts by mass per 100 parts by mass of solids content of the polyester resin emulsion, and the mixture was stirred for a predetermined time to obtain the anchor coat coating. The above anchor coat coating was applied to the substrate in the same manner as in Example 1, but the anchor coat coating repelled, and the barrier coat coating could not be applied.

[0061] (Reference example 1) In Example 1, evaluation samples were obtained using the same method as in Example 1, except that the anchor coat paint and barrier coat paint were not applied, and a 12 μm thick biaxially oriented polyester film (Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) was used as the base material.

[0062] (Evaluation method) Using the following evaluation methods, evaluation results for gas barrier laminates and evaluation samples were obtained, as shown in Tables 1 and 2.

[0063] [Evaluation of anchor coat coating (paint defects)] The anchor coat (AC) coating film formed after application and drying of the anchor coat paint was observed for the occurrence of repulsion (painting defects). ○ indicated no repulsion, and × indicated repulsion.

[0064] [Evaluation of gas barrier laminates (crack resistance)] The gas barrier laminates obtained in the examples and comparative examples were observed for the presence or absence of cracks (crack resistance). Those without cracks were marked with ○, and those with cracks were marked with ×.

[0065] [Oxygen permeability] Each evaluation sample obtained in the examples, comparative examples, and reference examples was measured using an oxygen permeability analyzer (Modern Control, OX-TRAN2 / 22). The measurement conditions were a temperature of 40°C and a relative humidity of 90%.

[0066] [Water vapor transmission rate] Each gas barrier property evaluation sample obtained in the examples, comparative examples, and reference examples was measured using an oxygen permeability analyzer (Modern Control, PERMATRAN-W 3 / 31). The measurement conditions were a temperature of 40°C and a relative humidity of 90%.

[0067] [Retort Test] Using the prepared evaluation samples, pouches (130cm x 170cm) were fabricated using an impulse sealer (Fuji Impulse Co., Ltd., V-301). 200g of pure water was filled into the resulting pouches. The pouches filled with pure water were subjected to a hot water shower retort test at 121°C for 30 minutes to evaluate their hot water resistance.

[0068] [Optical properties] For the gas barrier laminates obtained in the examples, comparative examples, and reference examples, total light transmittance (TT:%) and haze (Hz:%) were measured using a color computer (Suga Test Instruments Co., Ltd. SM-4), with the polyester film substrate side as the incident light side of the measurement. A ○ was used to indicate that the total light transmittance was 85% or higher and the haze was 30% or lower, while a × was used to indicate that it did not meet these criteria.

[0069] [X-ray fluorescence evaluation] The silicon element contained in each anchor coat layer obtained in the examples and comparative examples can be quantified using a commercially available X-ray fluorescence analyzer. By dividing the amount of Si(Si-Kα) detected in each anchor coat layer by the coating amount, the amount in the coating film can be determined as 1 g / m². 2 The silicon content per unit was calculated and used for evaluation. <Measurement conditions for X-ray fluorescence analyzer> Equipment used: Rigaku Corporation ZSXPrimusII Measurement conditions: Target of measurement: Si-Kα rays Measuring diameter: 10 mm Measured X-ray Rh (4.0 kW) The measurement is performed by irradiating the film surface with X-rays from the anchor coat coating side.

[0070] [T-peel strength] For the evaluation samples, the test force during peeling was measured using an Autograph (Shimadzu Corporation, AG-IS). The peel strength was measured using the test force in a T-peel when the uncoated adhesive area was clamped with air chucks on both sides, with a peeling width of 15 mm and a test speed of 300 mm / min.

[0071] The various measurement and evaluation results for the above examples, comparative examples, and reference examples are shown in Tables 1 and 2.

[0072] [Table 1]

[0073] [Table 2]

[0074] In Table 2, "*" means "material fracture." "Delami" means delamination. [Industrial applicability]

[0075] The gas barrier laminate of the present invention has an anchor coat layer that has excellent adhesion to the substrate and crack resistance, as well as a gas barrier layer that has excellent oxygen barrier and water vapor barrier properties. Therefore, even when subjected to retort sterilization, excellent gas barrier performance and delamination resistance are ensured, and it can be suitably used as a gas barrier packaging material, especially when retort sterilization is required. [Explanation of symbols]

[0076] 1. Substrate, 2. Anchor coat layer, 3. Gas barrier layer, 4. Heat-sealable resin layer.

Claims

1. In a gas barrier laminate having an anchor coat layer on at least one surface of a substrate, and a gas barrier layer containing at least a metal oxide formed on the anchor coat layer, A gas barrier laminate characterized in that the anchor coat layer comprises a hydrophilic group-containing resin and an epoxy-based silane coupling agent, the hydrophilic group-containing resin being a carboxyl group-containing polyester resin, and the epoxy-based silane coupling agent being blended in an amount greater than 100 parts by mass and less than 400 parts by mass per 100 parts by mass of the hydrophilic group-containing resin.

2. The gas barrier laminate according to claim 1, wherein the epoxy silane coupling agent is 3-glycidyloxypropyltrimethoxysilane.

3. The gas barrier laminate according to claim 1 or 2, wherein the carboxyl group-containing polyester resin has a glass transition temperature of 67°C or higher.

4. The gas barrier laminate according to any one of claims 1 to 3, wherein the carboxyl group-containing polyester resin is an amorphous polyester.

5. The gas barrier laminate according to any one of claims 2 to 4, wherein the 3-glycidyloxypropyltrimethoxysilane is blended in an amount of 150 to 300 parts by mass per 100 parts by mass of the polyester resin solids.

6. The gas barrier laminate according to any one of claims 1 to 5, wherein the value obtained by dividing the amount of Si (Si-kα) detected in the anchor coat layer by the coating amount is in the range of 1.6 to 3.

1.

7. The gas barrier laminate according to any one of claims 1 to 6, wherein the gas barrier layer is composed of a reaction product of a metal oxide and a phosphoric acid compound.

8. The gas barrier laminate according to any one of claims 1 to 7, wherein the gas barrier layer is composed of a reaction product of a metal oxide, a phosphoric acid compound, and an amine compound.

9. The gas barrier laminate according to any one of claims 1 to 7, wherein the gas barrier layer comprises a reaction product of a metal oxide, a phosphoric acid compound, and a carboxylate salt of a polyvalent metal soluble in phosphoric acid.

10. The gas barrier laminate according to any one of claims 7 to 9, wherein the metal oxide is zirconium oxide.

11. The gas barrier laminate according to any one of claims 7 to 10, wherein the phosphate compound is at least one of orthophosphate, metaphosphate, polyphosphate, and cyclic polyphosphate.

12. The gas barrier laminate according to any one of claims 9 to 11, wherein the carboxylate salt of the polyvalent metal comprises an amine compound containing a polyvalent metal ion and an organic carboxylic acid.

13. The gas barrier laminate according to claim 12, wherein the polyvalent metal ion is an aluminum ion and the amine compound is an amino acid.

14. The gas barrier laminate according to any one of claims 9 to 13, wherein the carboxylate salt of the polyvalent metal is aluminum glycinate.

15. The gas barrier layer has an infrared absorption spectrum of 1000 to 1130 cm⁻¹. －１ A gas barrier laminate according to any one of claims 1 to 14, having an absorption peak in which infrared absorption is maximum within the range.

16. The gas barrier laminate according to claims 1 to 15, wherein the gas barrier layer has a peak in which the binding energy of N by XPS is maximum in the range of 400 to 405 eV.

17. The substrate consists of a biaxially oriented polyester film with a thickness of 12 μm, and the anchor coat layer on the substrate is 0.01 to 10.0 g / m². ２ The anchor coat layer is formed with a thickness of 0.10 to 5.0 g / m², and the gas barrier layer is formed on the anchor coat layer with a thickness of 0.10 to 5.0 g / m². ２ In a case comprising a gas barrier laminate formed with a thickness of [amount] and an unoriented polypropylene film with a thickness of 50 μm via an adhesive, the oxygen permeability is 10 cc / m³. ２ - The humidity is below day / atm (40℃, 90% RH), and the water vapor transmission rate is 5.5 g / m³. ２ A gas barrier laminate according to any one of claims 1 to 16, wherein the temperature is 40°C and 90% RH or less.

18. The substrate consists of a biaxially oriented polyester film with a thickness of 12 μm, and the anchor coat layer on the substrate is 0.01 to 10.0 g / m². ２ The anchor coat layer is formed with a thickness of 0.10 to 5.0 g / m², and the gas barrier layer is formed on the anchor coat layer with a thickness of 0.10 to 5.0 g / m². ２ A gas barrier laminate formed with a thickness of , wherein the total light transmittance is 85% or more and the haze is 30% or less, according to any one of claims 1 to 17.

19. A container characterized by having a laminated structure of a gas barrier laminate according to any one of claims 1 to 18.

20. A paint composition for forming an anchor coat layer, which forms a gas barrier layer containing at least a metal oxide on a substrate, characterized in that it contains an epoxy silane coupling agent in an amount greater than 100 parts by mass and less than 400 parts by mass per 100 parts by mass of a water-soluble polyester resin and / or a water-dispersible polyester resin (solids).

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