Gas barrier coating composition and gas barrier laminate

Abstract

The present invention relates to a gas barrier coating composition comprising a metal oxide and a phosphoric acid compound, the gas barrier coating composition further comprising at least one of a metal alkoxide, a hydrolysate of the metal alkoxide, and a metal hydroxide, thus, it is possible to provide: a coating composition which has more excellent oxygen barrier properties and water vapor barrier properties and is capable of efficiently forming a colorless and transparent gas barrier coating film; and a gas barrier laminate which is provided with the gas barrier coating film (gas barrier layer).

Description

Technical Field

[0001] The present invention relates to a gas barrier coating composition and a gas barrier laminate having a coating film formed from the coating composition, and more specifically, to a coating composition having excellent oxygen barrier properties and water vapor barrier properties and capable of suppressing yellowing of the coating film, and a gas barrier laminate including the coating film. Background Art

[0002] Conventionally, there is known a gas barrier laminate in which a film having metal atoms and phosphorus atoms as constituent components is formed on a plastic substrate. For example, the following patent document 1 proposes a substantially continuous and substantially non-crystalline anti-permeable film comprising the following metal orthophosphate, in which the atomic ratio of metal to phosphorus is approximately 2.3 to 0.5, 50 to 100% of the metal atoms are aluminum, 0 to 50% of the metal atoms are selected from tin, titanium and zirconium, and 0 to about 20% of the metal atoms are selected from zinc, chromium and magnesium.

[0003] However, the oxygen barrier and water vapor barrier properties of the gas permeation-proof film are still unsatisfactory. In addition, resin is added to improve the adhesion to the coated substrate, but the effect of improving the oxygen and water vapor barrier properties of the coating film by adding resin is not clear. In order to solve such a problem, the following Patent Document 2 describes a composite structure comprising a substrate (X) and a layer (Y) laminated on the substrate (X), wherein the layer (Y) contains a reaction product (R), which is a reaction product formed by the reaction of at least a metal oxide (A) and a phosphorus compound (B), and has a relative humidity of 800 to 1400 cm -1 In the infrared absorption spectrum of the layer (Y) within the range of 1 ) at 1080~1130cm -1 Within the range of , the metal atoms (M) constituting the metal oxide (A) are aluminum.

[0004] The composite structure described in Patent Document 2 satisfies both oxygen barrier properties and water vapor barrier properties, but there are concerns about stability with respect to acids and bases contained in the content. The present inventors have proposed a coating composition that solves the above-mentioned problems by comprising a composite structure containing a reaction product of a metal oxide and a phosphorus compound and that exhibits more excellent oxygen barrier properties and water vapor barrier properties by containing specific additives (Patent Document 3). Prior art literature Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 57-42032 Patent Document 2: Japanese Patent No. 4961054 Patent document 3: International Publication No. 2022 / 075352 Summary of the invention Problems to be solved by the invention

[0006] In the gas barrier coating composition of the above-mentioned Patent Document 3, an amine compound containing polyvalent metal ions and an organic carboxylic acid is used as a specific additive, so that the polyvalent metal ions supplement the metal ions, and the above-mentioned amine compound reacts with the metal ions, carboxylic acid and phosphoric acid to be introduced into the cross-linked structure, and acts as a binder between metal oxide particles, thereby forming a defect-free coating film and exhibiting more excellent oxygen barrier properties and water vapor barrier properties. However, the coating film formed by the coating composition of Patent Document 3 has a tendency to be colored yellow due to the reaction of the above-mentioned amine compound and a carboxylic acid as a kind of carbonyl compound, and therefore cannot be fully satisfied in the application requiring a colorless and transparent coating film. In addition, since the reaction of the amine compound and the carboxylic acid requires high temperature and long time, it is desired to have a coating composition that can efficiently form a coating film at low temperature and in a short time.

[0007] Therefore, the object of the present invention is to provide a coating composition having more excellent oxygen barrier properties and water vapor barrier properties and capable of efficiently forming a colorless and transparent gas barrier coating film, and a gas barrier laminate having the gas barrier coating film (gas barrier layer), in a gas barrier coating composition formed of a metal oxide and a phosphoric acid compound. Solutions for solving problems

[0008] According to the present invention, there is provided a gas barrier coating composition, characterized in that it contains: at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide; a metal oxide; and a phosphoric acid compound or a sulfuric acid compound.

[0009] In the gas barrier coating composition of the present invention, it is preferred that [1] The metal species of the metal alkoxide and the metal hydroxide is at least one of aluminum, titanium, iron and zirconium, [2] The metal alkoxide is at least one of methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, and tert-butoxide, [3] The metal alkoxide is aluminum isopropoxide, [4] The metal hydroxide is aluminum hydroxide, [5] The metal oxide is zirconium oxide or aluminum oxide, [6] The phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

[0010] According to the present invention, there is also provided a gas barrier laminate, characterized in that the gas barrier laminate is a gas barrier laminate having a coating film formed from the above-mentioned gas barrier coating composition on a substrate, and the coating film is formed by a reaction product obtained by reacting at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide with a metal oxide and a phosphoric acid compound or a sulfuric acid compound.

[0011] In the gas barrier laminate of the present invention, it is preferred that [1] The coating film has a b* value of less than 2.2 as measured by colorimetry, [2] the content ratio (Al / Zr) of Zr (Zr-kα) and Al (Al-kα) in the coating film measured by fluorescent X-ray is within the range of 0.06 to 0.35, [3] The value of the content ratio (P / Zr) of Zr (Zr-kα) and P (P-kα) in the fluorescent X-ray measurement of the coating film is in the range of 1.30 to 1.82, [4] having an adhesion-promoting coating between the substrate and the coating film, [5] The substrate is formed of a 12 μm thick biaxially stretched polyester, and a coating of 2.0 g / m 2 In the case where a 50 μm thick cast polypropylene film is disposed on the coating film via an adhesive layer, the oxygen permeability is 25 cc / m 2 ·day·atm (40℃90%RH) or less, and water vapor permeability is 5.5g / m 2 · Days (40℃90%RH) or less. Effects of the Invention

[0012] In the gas barrier coating composition of the present invention, by containing at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide together with a metal oxide and a phosphoric acid compound, a coating film having excellent oxygen barrier properties and water vapor barrier properties due to a uniform and dense crosslinked structure formed by the metal oxide and the phosphoric acid compound, and excellent transparency without yellowing can be efficiently formed. That is, metal alkoxides and their hydrolyzates and metal hydroxides can supplement metal ions under acidic conditions to eliminate metal ion deficiency, and react with phosphoric acid compounds to be introduced into the above-mentioned cross-linked structure, functioning as a binder between metal oxide particles, thereby forming a coating film with few defects, and thus, combined with the above-mentioned uniform and dense cross-linked structure, can reflect more excellent oxygen barrier properties and water vapor barrier properties. As a result, according to the gas barrier coating composition of the present invention, not to mention the gas barrier laminate for non-retorting purposes, a gas barrier laminate that can cope with retorting sterilization can also be provided. In addition, the reaction of metal alkoxides and their hydrolyzates and metal hydroxides with phosphoric acid compounds does not produce yellowing, so a colorless and transparent gas barrier coating film can be formed. Furthermore, compared with the previous coating film formation containing amine compounds and carboxylic acids, it can be formed at a low temperature and in a short time, so it is also excellent in productivity. Furthermore, by using zirconium oxide as the metal oxide, a coating film that is stable against acids and alkalis contained in the content can be formed, and further excellent oxygen barrier properties and water vapor barrier properties can be exhibited. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram showing a cross-sectional structure of an example of the gas barrier laminate of the present invention. Figure 2 It is a diagram showing the cross-sectional structure of another example of the gas barrier laminate of the present invention. DETAILED DESCRIPTION

[0014] (Gas barrier coating composition) The important feature of the gas barrier coating composition of the present invention is that it contains: at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide (hereinafter, these three are sometimes collectively referred to as "metal alkoxides, etc."); a metal oxide; and a phosphoric acid compound or a sulfuric acid compound (hereinafter, these are sometimes collectively referred to as "phosphoric acid compounds, etc."). As described above, in the present invention, by containing at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide together with a metal oxide, a phosphoric acid compound, or a sulfuric acid compound, a uniform and dense cross-linked structure is formed by the metal oxide and the phosphoric acid compound, and the metal alkoxide reacts with the phosphoric acid compound to be introduced into the above-mentioned cross-linked structure, acting as a binder between metal oxide particles, thereby exhibiting excellent oxygen barrier properties and water vapor barrier properties. Furthermore, the reaction between the metal alkoxide and the phosphoric acid compound does not cause yellowing as in the coating composition described in Patent Document 3, and thus a colorless and transparent gas barrier coating film can be formed.

[0015] [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, but is not limited thereto. Examples thereof include oxides of magnesium, calcium, iron, zinc, aluminum, silicon, titanium, zirconium, and the like. Among them, zirconium oxide can be preferably used. The metal oxide used in this specification contains a structure represented by MOM as a main component. M represents a metal atom, and O represents an oxygen atom. In addition, zirconium oxide contains Zr and O as component elements, and as an amorphous zirconium oxide, it contains zirconium hydroxide (Zr(OH)4) and / or zirconium oxyhydroxide (ZrO(OH)2) as main components, and as a crystalline zirconium oxide, it contains hydrated zirconium oxide (ZrO2·xH2O) and / or zirconium oxide (ZrO2) as main components. It should be noted that the main component refers to a component contained in a ratio of 50% or more. The crystallinity of zirconium oxide and zirconium oxide with a gas barrier coating can be evaluated by using a conventionally known X-ray structure diffraction device to identify the characteristic X-ray peaks of crystalline zirconium. In the present invention, the zirconium oxide may be either crystalline or amorphous zirconium oxide (zirconium oxide).

[0016] In the coating, zirconium oxide is used in the form of a sol of an inorganic acid such as nitric acid, in which zirconium oxide particles are used as a dispersant and a stabilizer is added. In the present invention, in order to prevent the volatilization of the acid during the formation of the coating film due to the presence of an inorganic acid, it is preferred to use the following zirconium oxide sol instead of an inorganic acid such as nitric acid, wherein the zirconium oxide sol uses a carbonate, ammonium carbonate salt, an organic dispersant, or the like. Furthermore, since the binder component contains at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide that can provide a large amount of hydroxyl groups for reacting with phosphoric acid, even when crystalline zirconium oxide is used, the same oxygen barrier property and water vapor barrier property as in the case of using amorphous zirconium oxide having a large amount of hydroxyl groups can be achieved.

[0017] In addition, it is desirable that the average particle size (D50) of the primary particles of the zirconium oxide particles is 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less, thereby forming a uniform coating film with excellent transparency. It should be noted that the average particle size (D50) is a volume average particle size measured by a laser diffraction / scattering method, and D50 is a value of 50% in a volume-based particle size distribution. By using such a microparticle-type zirconium oxide as a raw material, excellent transparency can be achieved.

[0018] [Phosphoric acid compounds] As the phosphoric acid compound used in the present invention, orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid and their derivatives can be listed. As specific examples of polyphosphoric acid, pyrophosphoric acid, triphosphoric acid, polyphosphoric acid formed by condensation of four or more phosphoric acids, etc. As examples of the above-mentioned derivatives, orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, their salts, (partial) ester compounds, halides (chlorides, etc.), dehydrates (phosphorus pentoxide, etc.) and the like can be listed. In addition, examples of derivatives of phosphonic acid also include compounds in which the hydrogen atom directly bonded to the phosphorus atom of phosphonic acid (HP(=O)(OH)2) is substituted by an alkyl group optionally having various functional groups (for example, nitrilotris(methylenephosphonic acid), N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid) and the like), salts thereof, (partial) ester compounds, halides and dehydrates. Furthermore, organic polymers having phosphorus atoms such as phosphorylated starch can also be used. These phosphoric acid compounds can be used alone or in combination of two or more. In the present invention, it is particularly preferred to use at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

[0019] [Sulfate compounds] In the present invention, as the sulfuric acid compound which can react with the metal oxide to form a dense coating film instead of the above-mentioned phosphoric acid compound, there can be exemplified compounds selected from the group consisting of sulfuric acid, sulfates, sulfate esters, alkyl sulfuric acid, polyoxyethylene alkyl ether sulfuric acid and salts thereof. These sulfuric acid compounds can be used alone or in combination of two or more. In the present invention, sulfuric acid can be particularly preferably used.

[0020] [Metal alkoxide or its hydrolyzate] The metal alkoxide is generally represented by the following formula (1). M n+ (OR)n-……(1) In the formula, R represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n represents an integer of 1 or more.

[0021] In the present invention, in the above formula (1), the metal atom M is preferably any one of aluminum, titanium, iron and zirconium. Furthermore, in the above formula (1), the organic group R is preferably any one of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a tert-butyl group. In the present invention, as described above, the metal alkoxide is preferably at least one metal alkoxide selected from methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, and tert-butoxide, among which aluminum isopropoxide can be preferably used.

[0022] [Metal hydroxide] The metal hydroxide is generally represented by the following formula (2). M n+ (OH)n-……(2) In the formula, H represents a hydrogen atom, M represents a metal atom, and n represents an integer of 1 or more. As the metal hydroxide, any hydroxide of aluminum, titanium, iron, and zirconium exemplified as the metal alkoxide is preferred, and among them, aluminum hydroxide can be preferably used.

[0023] [Preparation of coating composition] The gas barrier coating composition of the present invention may be any composition of an aqueous system or a solvent system as long as it contains the above-mentioned metal oxide, phosphoric acid compound, etc., and metal alkoxide, etc., and is preferably an aqueous composition. Preferably, a sol containing metal oxide fine particles as a dispersoid is used as the metal oxide in the gas barrier coating composition. In addition, as the sol containing metal oxide fine particles as a dispersoid, it is preferred to use a sol that does not contain a volatile acid as a stabilizer in order to suppress the adverse effects of acid generation on equipment and the working environment. For the above reasons, it is desirable not to use a volatile acid such as nitric acid, hydrochloric acid, or acetic acid as a deflocculant in order to produce a dispersion having excellent transparency and viscosity stability.

[0024] The gas barrier coating composition of the present invention is prepared by mixing a metal oxide, a phosphoric acid compound, etc., and a metal alkoxide, etc. in a solvent capable of dissolving the phosphoric acid compound, etc., and the metal alkoxide, etc. As such an aqueous medium, distilled water, ion exchange water, pure water and other conventionally known aqueous solvents can be used. As with the known aqueous composition, alcohols, polyols, derivatives thereof, etc.; organic solvents such as ketones can be contained. When such a co-solvent is used, 1 to 90% by mass can be contained relative to the aqueous solvent in the aqueous composition. By containing the solvent in the above range, the film forming performance is improved. As such an organic solvent, an amphiphilic organic solvent is preferably used, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, 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, acetone, methyl ethyl ketone, etc. can be listed.

[0025] In addition, in the preparation of the gas barrier coating composition of the present invention, a generally known dispersion treatment can be performed. As a method of dispersion treatment, a pulverization treatment of fine particles using cavitation using an ultrasonic homogenizer, a mechanical dispersion treatment using a disperser using a rotary blade, and a dispersion using a grinder using glass or zirconia beads are known. In the present invention, the microdispersion treatment of these coatings can be preferably used.

[0026] In the gas barrier coating composition of the present invention, a phosphoric acid compound or the like, a metal alkoxide or the like may be added to the metal oxide within a range that does not impair the oxygen barrier property and the water vapor barrier property. Regarding the phosphoric acid compound, the amount added varies depending on the type of the phosphoric acid compound used and cannot be generally specified, but when zirconium oxide is used as the metal oxide, phosphoric acid is used as the phosphoric acid compound, and aluminum isopropoxide is used as the metal alkoxide, the non-volatile component of phosphoric acid is preferably added in an amount of 53 to 86 parts by mass, particularly 53 to 64 parts by mass, relative to 100 parts by mass of the solid content of zirconium oxide.

[0027] In addition, the amount of metal alkoxides etc. added varies depending on the type of metal alkoxides etc. used and cannot be generally specified, but when zirconium oxide is used as the metal oxide, phosphoric acid is used as the phosphate compound etc., and aluminum isopropoxide is used as the metal alkoxide etc., it is particularly preferred to add aluminum isopropoxide in an amount of 45 to 49 parts by mass relative to 100 parts by mass of the solid content of zirconium oxide. When the added amount is less than the above range, the effect obtained by adding the metal alkoxide cannot be fully obtained compared with the case within the above range. Even if the added amount is more than the above range, not only can no further effect be obtained, but the barrier structure of the coating film may be defective compared with the case within the above range.

[0028] The gas barrier coating composition of the present invention preferably contains a catalyst that promotes the reaction between the metal oxide or metal alkoxide used and the phosphoric acid compound, etc. This can promote the crosslinking reaction of the coating composition and reduce the heating temperature and heating time for forming the coating film. Examples of such a catalyst include acid catalysts such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalene disulfonic acid, and cumenesulfonic acid, or amine-neutralized products of these acids. Among them, p-toluenesulfonic acid is preferably used. The acid catalyst is preferably contained in an amount of 0.1 to 10 parts by mass, particularly preferably 1 to 3 parts by mass, based on 100 parts by mass of the solid content of the zirconium oxide. The gas barrier coating composition may contain, in addition to the above-mentioned components, a crosslinking agent, a metal complex, a condensation accelerator, a polymer compound, a filler, a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant, a defoaming agent, a colorant, and the like.

[0029] (Gas barrier coating) The gas barrier coating film formed by the gas barrier coating composition of the present invention comprises the above-mentioned metal oxide, phosphoric acid compound, etc. and metal alkoxide, etc. Specifically, a metal phosphate is formed, and the metal oxide and the phosphoric acid compound are cross-linked, thereby forming a dense cross-linked structure. In addition, the metal alkoxide, etc. reacts with phosphoric acid to form a metal phosphate and is introduced into the above-mentioned cross-linked structure, acting as a binder between metal oxide particles, and a defect-free coating film can be formed. The coating film formed by the gas barrier coating composition of the present invention has the following characteristics: the coating film alone has a wavelength of 800 to 1400 cm-1 as measured by FT-IR. -1 In the infrared absorption spectrum within the range of 940-1120cm -1 The infrared absorption has the maximum absorption peak in the range of .

[0030] In addition, the gas barrier coating film of the present invention does not yellow as in the case of using a polyamidation reaction based on an amine compound and a carboxylic acid as described above, and the coating film is preferably 2.0 g / m2 on a 12 μm thick biaxially stretched PET film. 2 The coating film formed by the coating amount has a b* value of less than 2.2, especially less than 1.5 in color measurement (L*a*b* colorimetric system specified by CIE in 1976), and the yellowness is reduced.

[0031] Furthermore, in the coating film formed from the gas barrier coating composition of the present invention, the value of the content ratio (P / M) of M (M-kα) of a metal oxide or metal alkoxide, etc., obtained by fluorescent X-ray measurement to P (P-kα) of a phosphoric acid compound, etc., obtained by fluorescent X-ray measurement, particularly when zirconium oxide is used as the metal oxide, phosphoric acid is used as the phosphoric acid compound, and aluminum isopropoxide is used as the metal alkoxide, the value of the content ratio (P / Zr) of Zr (Zr-kα) obtained by fluorescent X-ray measurement of zirconium oxide to P (P-kα) obtained by fluorescent X-ray measurement of the phosphoric acid compound is preferably in the range of 1.30 to 1.82, and particularly preferably in the range of 1.36 to 1.82. By making the above-mentioned content ratio within the above-mentioned range, in the coating film, the phosphoric acid compound reacts efficiently with the hydroxyl group of the metal oxide without excess or deficiency, and a uniform and dense coating film can be formed, which can exhibit excellent oxygen barrier properties and water vapor barrier properties. That is, if the content ratio obtained by fluorescent X-ray measurement is less than the above-mentioned range, the phosphoric acid compound is insufficient, the bonding between the metal oxide particles is insufficient, and the amount of hydroxyl groups present on the surface of the metal oxide particles increases, and the oxygen barrier properties and water vapor barrier properties may be reduced. On the other hand, if the content ratio obtained by fluorescent X-ray measurement is greater than the above-mentioned range, the phosphoric acid compound is excessive, and the amount of hydroxyl groups derived from the phosphoric acid group increases, and the oxygen barrier properties and water vapor barrier properties may still be reduced.

[0032] In addition, when zirconium oxide is used as the metal oxide, phosphoric acid is used as the phosphoric acid compound, and aluminum isopropoxide is used as the metal alkoxide, the content ratio (Al / Zr) of Zr (Zr-kα) obtained by fluorescence X-ray measurement of zirconium oxide and Al (Al-kα) obtained by fluorescence X-ray measurement of aluminum isopropoxide is preferably in the range of 0.06 to 0.35, and particularly preferably in the range of 0.13 to 0.26. By making the above content ratio within the above range, the dense cross-linked structure formed by zirconium oxide and the phosphoric acid compound is not damaged, the above-mentioned effects of the metal alkoxide can be exhibited, and excellent oxygen barrier properties and water vapor barrier properties can be exhibited.

[0033] (Gas Barrier Laminate) The gas barrier laminate of the present invention is a laminate having a gas barrier layer formed of the gas barrier coating film on at least one surface of a substrate. Figure 1 As shown, a gas barrier layer 3 is formed on a substrate 1 via an adhesion promoter coating 2 described later. The adhesion promoter coating 2 is a coating film having excellent adhesion to the plastic substrate 1. By forming the gas barrier layer on the coating film, the interlayer adhesion between the gas barrier layer and the plastic substrate is significantly improved, and even when retorting sterilization is performed, the gas barrier layer can be effectively prevented from peeling off from the substrate. Furthermore, the gas barrier laminate having the above-mentioned structure has excellent transparency with a total light transmittance of 80% or more and a haze of 30% or less. Furthermore, in the gas barrier layered product of the present invention, if Figure 2 As shown, it is preferable that a moisture-resistant resin layer 5 made of a thermoplastic resin such as a cast polypropylene resin film is formed on the gas barrier layer 3 via an adhesive layer 4 .

[0034] The gas barrier layer of the gas barrier laminate of the present invention has sufficient gas barrier properties, especially oxygen barrier properties and water vapor barrier properties. The gas barrier laminate comprises a 12 μm thick substrate film made of biaxially stretched polyester and a coating amount of 2.0 g / m 2The gas barrier coating (gas barrier layer), the adhesive layer, and the 50 μm thick cast polypropylene film have the following excellent oxygen barrier properties and boiling resistance: oxygen permeability (according to JIS K-7126) is 25cc / m 2 ·day·atm (40℃90%RH) or less, and water vapor permeability is 5.5g / m 2 · Days (40℃90%RH) or less.

[0035] [Base material] As the substrate of the gas barrier laminate, a conventionally known substrate composed of resins such as thermoplastic resins and thermosetting resins, fibers such as paper and non-woven fabrics can be used, but preferably, films, sheets, or any packaging materials in the form of bottles, cups, trays, cans, etc. made from thermoplastic resins that can be thermoformed by methods such as extrusion molding, biaxially stretched film molding, cast film molding, injection molding, blow molding, stretch blow molding or pressure molding can be listed.

[0036] Examples of the thermoplastic resin constituting the substrate include olefin copolymers such as low-, medium- or high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-1-butene copolymers, ionomers, ethylene-vinyl acetate copolymers, and ethylene-vinyl alcohol copolymers; 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 meta-xylylene adipamide; styrene copolymers such as polystyrene, styrene-butadiene block copolymers, styrene-acrylonitrile copolymers, and styrene-butadiene-acrylonitrile copolymers (ABS resin); vinyl chloride copolymers such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymers; acrylic copolymers such as polymethyl methacrylate and methyl methacrylate / ethyl acrylate copolymers; polycarbonate, etc. Furthermore, from the viewpoint of recent environmental measures, chemically recycled polyethylene terephthalate, mechanically recycled polyethylene terephthalate, biomass-derived polyethylene terephthalate, biomass-derived olefins, recycled olefins, and the like can be used. In the present invention, a sheet made of polyethylene terephthalate, polybutylene terephthalate, or polypropylene can be particularly preferably used.

[0037] These thermoplastic resins can be used alone, or can exist in the form of two or more blends, and different resins can exist in the form of laminates. In addition, the plastic substrate can be a monolayer structure, or can be a laminated structure of two or more layers obtained by simultaneous melt extrusion, other laminations. The above-mentioned melt-moldable thermoplastic resin may, if desired, contain one or more additives such as a pigment, an antioxidant, an antistatic agent, an ultraviolet absorber, a lubricant, etc. in an amount of 0.001 to 5.0 parts by mass based on 100 parts by mass of the resin. In addition, for example, in order to strengthen the container, one or more of fiber reinforcing materials such as glass fiber, aromatic polyamide fiber, carbon fiber, pulp, cotton / cotton linter, or powder reinforcing materials such as carbon black and white carbon black, or sheet reinforcing materials such as glass flakes and aluminum flakes can be added in an amount of 2 to 150 parts by mass relative to 100 parts by mass of the thermoplastic resin. Furthermore, for the purpose of increasing the volume, one or more of heavy or soft calcium carbonate, mica, talc, kaolin, gypsum, clay, barium sulfate, aluminum oxide powder, silicon dioxide powder, magnesium carbonate, etc. can be added in an amount of 5 to 100 parts by mass relative to 100 parts by mass of the thermoplastic resin according to a formulation known per se. Furthermore, for the purpose of improving the gas barrier properties, scaly inorganic fine powder, such as water-swellable mica and clay, may be blended in an amount of 5 to 100 parts by mass based on 100 parts by mass of the thermoplastic resin according to a known formulation. Similarly, in order to improve the gas barrier properties, a thin film layer of an inorganic substance such as silicon oxide or aluminum oxide may be physically or chemically provided on a plastic substrate using a vapor deposition method.

[0038] In addition, the substrate may be a film, sheet, or a molded product such as a container, or the coating may be pre-set on a preformed product for forming a container. Examples of such preforms include: a bottomed or bottomless cylindrical parison for biaxial stretch blow molding; a tube for plastic container molding; a sheet for vacuum molding, pressure molding, or plug-assist molding; or a film for heat sealing or bag making.

[0039] [Adhesion-promoting coating] As an adhesion-enhancing coating formed on the surface of the substrate as needed, an adhesion-enhancing coating used in a gas barrier laminate can be used, preferably: an adhesion-enhancing coating formed by a previously known polyurethane resin composed of a combination of an acrylic resin, a hydroxyl-containing compound serving as a main agent such as a polyol, and an isocyanate curing agent, or an adhesion-enhancing coating further compounded with a silane coupling agent, or an adhesion-enhancing coating formed by a resin containing a hydrophilic group and a silane coupling agent.

[0040] <Polyurethane resin> As the polyurethane resin constituting the anchor coating layer, a known polyurethane resin conventionally used for the anchor coating layer can be used, which contains a hydroxyl-containing compound and an isocyanate compound as a main component of an acrylic resin, a polyol, etc. In the present invention, it is desirable that the polyurethane resin has a glass transition temperature (Tg) of 80° C. or higher, particularly a polyurethane resin in the range of 80° C. to 120° C. When the glass transition temperature is lower than the above range, the heat resistance of the anchor coating layer is poorer than that in the above range, and when the gas barrier layer is dried, the gas barrier coating film may shrink due to heating, causing cracks in the gas barrier layer and reducing the barrier properties.

[0041] As the acrylic resin, there can be used a polymer or copolymer synthesized by solution polymerization or suspension polymerization using a conventionally known radical initiator or the like. The glass transition temperature of the acrylic resin is preferably -50 to 100° C., more preferably 40 to 100° C. The number average molecular weight of the acrylic resin is preferably 500,000 to 100,000, more preferably 500,000 to 80,000. The hydroxyl value of the acrylic resin is preferably 10 to 200 mgKOH / g, more preferably 80 to 180 mgKOH / g. The monomer for forming the copolymer is not particularly limited, and a copolymer obtained by combining methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, maleic acid, 2-hydroxyethyl methacrylate, tert-butyl acrylate, etc. as needed can be used. Examples of the polyol include diol, polyester polyol, polyether polyol, acrylic polyol, and urethane-modified products thereof, and acrylic polyol and diol are particularly preferably used.

[0042] The glass transition temperature of the polyester polyol is preferably -50 to 100° C., and more preferably -20 to 80° C. The number average molecular weight of these polyester polyols is preferably 500,000 to 100,000, and more preferably 500,000 to 80,000. Examples of the diol include ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, and 1,6-hexanediol.

[0043] As the isocyanate component which is a curing agent for the polyurethane resin, aromatic diisocyanate, aromatic aliphatic diisocyanate, alicyclic diisocyanate, aliphatic diisocyanate, etc. can be used. Examples of the aromatic diisocyanate include toluene diisocyanate (2,4- or 2,6-toluene diisocyanate or a mixture thereof) (TDI); phenylene diisocyanate (meta-, para-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'-xylene diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate, and the like. Examples of the aromatic aliphatic diisocyanate include xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or a mixture thereof) (XDI), tetramethylxylylene diisocyanate (1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof) (TMXDI), and ω,ω′-diisocyanate-1,4-diethylbenzene.

[0044] Examples of the alicyclic diisocyanate include 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanate methyl-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(isocyanate methyl)cyclohexane (1,3- or 1,4-bis(isocyanate methyl)cyclohexane or a mixture thereof) (hydrogenated XDI), and the like.

[0045] Examples of the aliphatic diisocyanate 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 caffeic acid methyl ester.

[0046] The polyisocyanate component may be a polyfunctional polyisocyanate compound such as isocyanurate, biuret, or allophanate derived from the above-mentioned polyisocyanate monomer, or a polyfunctional polyisocyanate compound containing 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 particularly 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, xylylene diisocyanate is also preferably used among the above isocyanate components.

[0047] <Hydrophilic Group-Containing Resin> The resin containing a hydrophilic group is not limited thereto, and examples thereof include water-dispersible or water-soluble polyester resins, water-dispersible or water-soluble acrylic resins, water-dispersible or water-soluble polyurethane resins, etc. In the present invention, polyester resins are preferred, and among them, carboxyl-containing polyester resins can be preferably used.

[0048] The carboxyl group-containing polyester resin can be prepared by combining a carboxylic anhydride such as phthalic anhydride, succinic anhydride, maleic anhydride, trimellitic anhydride, itaconic anhydride, and citraconic anhydride with a monomer component generally used for polymerization of a polyester resin. As for the monomer components, as the polycarboxylic acid component, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid; unsaturated dicarboxylic acids such as maleic acid (anhydride), fumaric acid, and terpene-maleic acid adducts; alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid, tetrahydrophthalic acid, hexahydroisophthalic acid, and 1,2-cyclohexene dicarboxylic acid; polycarboxylic acids having a valence of more than three such as trimellitic acid (anhydride), pyromellitic acid (anhydride), and methylcyclohexene tricarboxylic acid, etc., and one or more of them can be selected and used. In the present invention, from the viewpoint of heat resistance, the proportion of aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid in the polycarboxylic acid component constituting the polyester resin is preferably 50 mol% or more.

[0049] In addition, the polyol component constituting the polyester resin is not particularly limited, and one or more of the following can be used: ethylene glycol, propylene glycol (1,2-propylene glycol), 1,3-propylene glycol, 1,4-butylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 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-dimethyl-1,5-pentanediol, 1-methyl-1, Aliphatic diols such as 8-octanediol, 3-methyl-1,6-hexanediol, 4-methyl-1,7-heptanediol, 4-methyl-1,8-octanediol, 4-propyl-1,8-octanediol, and 1,9-nonanediol; ether alcohols such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alicyclic polyols such as 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, tricyclodecanediols, and hydrogenated bisphenols; trivalent or higher polyols such as trimethylolpropane, trimethylolethane, and pentaerythritol, etc. In the present invention, among the above-mentioned polyol components, ethylene glycol, propylene glycol, and neopentyl glycol can be appropriately used.

[0050] The carboxyl group-containing polyester resin can be produced by the following well-known methods: polycondensing one or more of the above-mentioned polycarboxylic acid components and one or more of the polyol components, depolymerizing the polycarboxylic acid component such as terephthalic acid, isophthalic acid, trimellitic anhydride, trimellitic acid, pyromellitic acid, etc. after the polycondensation, and further, ring-opening addition of an acid anhydride such as phthalic anhydride, maleic anhydride, trimellitic anhydride, ethylene glycol bis(trimellitic acid) dianhydride, etc. after the polycondensation.

[0051] The carboxyl group-containing polyester resin preferably has an acid value of 1 to 80 KOHmg / g, particularly preferably 10 to 30 KOHmg / g, and a glass transition temperature (Tg) of 0 to 120°C, particularly preferably 67 to 80°C. The carboxyl group-containing polyester resin used may be a mixed polyester resin as long as the acid value and Tg after mixing are controlled within the above ranges. Furthermore, the carboxyl group-containing polyester resin is preferably an amorphous polyester.

[0052] <Silane coupling agent> As the silane coupling agent used in the anchor coating layer, an epoxy-based silane coupling agent can be preferably used. As such epoxy-based silane coupling agents, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like can be used. Examples of the silane coupling agent include tetramethoxysilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-isocyanatepropyltriethoxysilane, and these can be used as needed. In addition, for the purpose of improving hot water-resistant adhesion, the silane coupling agent used may be subjected to hydrolysis or condensation reaction of the silane coupling agent as needed.

[0053] [Anchor coating composition] In the present invention, the anchor coating layer-forming composition may be either an aqueous composition or a solvent composition, but an aqueous composition is preferably used from the viewpoint of the working environment. When the above-mentioned polyurethane resin is used in the anchor coating layer-forming composition, it is preferred that the composition further contains an epoxy-based silane coupling agent. In addition, the polyurethane resin used is preferably a water-soluble or water-dispersible polyurethane. On the other hand, when the above-mentioned hydrophilic group-containing resin is used in the anchor coating layer-forming composition, it is preferably prepared by containing a carboxyl group-containing polyester resin and an epoxy-based silane coupling agent. The epoxy silane coupling agent is preferably contained in an amount of 1 to 80 parts by mass relative to 100 parts by mass of the solid content of the polyurethane resin, and is preferably contained in an amount of 100 to 400 parts by mass, particularly preferably 150 to 300 parts by mass relative to 100 parts by mass of the solid content of the carboxyl group-containing polyester resin. When the epoxy silane coupling agent is less than the above range, satisfactory crack resistance during drying cannot be obtained compared with the case of being within the above range. On the other hand, even if the epoxy silane coupling agent is blended in an amount exceeding the above range, it is difficult to further improve the adhesion and crack resistance, and hot water resistance may be impaired, which is also worse from the viewpoint of economic efficiency.

[0054] The aqueous medium may contain the same conventionally known aqueous medium, alcohol, polyol, or organic solvent such as a derivative thereof as used in the gas barrier layer-forming composition. In addition to the above-mentioned components, the composition for forming the adhesion-enhancing coating may also contain known curing accelerators, fillers, softeners, antioxidants, stabilizers, adhesion promoters, leveling agents, defoaming agents, plasticizers, inorganic fillers, tackifying resins, fibers, colorants such as pigments, agents for extending the usable time, etc.

[0055] (Method for producing 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 may be directly applied to at least one surface of the substrate, but it is preferred to apply the anchor coating layer-forming composition before applying the gas barrier coating composition. The coating amount of the anchor coating composition is determined by the content of the polyurethane resin or carboxyl-containing polyester resin and the silane coupling agent in the composition and cannot be generally specified. However, it is preferably 0.05 to 1.00 g / m2 based on the solid content weight of the coating film. 2 It is preferably applied in a range of 0.10 to 0.50 g / m2 in terms of solid content weight of the coating film. 2 If the amount of the anchor coating applied is less than the above range, the anchor coating may not be fixed to the substrate compared to the case within the above range. On the other hand, if the amount of the anchor coating applied is more than the above range, the economic efficiency becomes poor. The composition for forming an anchor coating layer applied to the substrate depends on the composition used and the amount of coating, but the solvent in the composition is removed by drying at a temperature of 80°C to 150°C for 1 second to 60 seconds. This makes it possible to economically form an anchor coating layer without causing any influence even when the substrate is made of a plastic having a low melting point such as polypropylene.

[0056] Next, the gas barrier coating composition is applied on the anchor coating composition in a dry state after the solvent is removed. The amount of the gas barrier coating composition applied is determined by the content of the metal oxide, phosphoric acid compound, etc., and metal alkoxide, etc. in the composition, and cannot be generally specified, but is preferably 0.05 to 3.0 g / m2 in terms of the solid content weight of the coating film. 2 It is preferably applied in a range of 0.1 to 2.0 g / m2 in terms of solid content weight of the coating film. 2 If the coating amount is less than the above range, sufficient barrier properties cannot be obtained. On the other hand, even if the coating amount is more than the above range, it is only economically poor and has no special advantages. In the gas barrier coating composition of the present invention, although it also depends on the composition and coating amount of the metal oxide, phosphoric acid compound, etc. and metal alkoxide, etc. in the composition used, a gas barrier layer can be formed by heating at a temperature of 80 to 220°C, preferably at a temperature of 140 to 220°C for 1 second to 10 minutes. As a result, the difference in shrinkage caused by heating the gas barrier layer and the anchor coating layer can be reduced, the crack resistance of the gas barrier layer can be improved, and the interlayer adhesion between the gas barrier layer and the anchor coating layer is also significantly improved, and even when boiling sterilization is implemented, the gas barrier layer is prevented from peeling off from the substrate. In addition, compared with the conventional gas barrier layer, the coating film can be efficiently formed at a low temperature and in a short time.

[0057] The anchor coating-forming composition and the gas barrier coating composition may be applied, dried or heat-treated by conventionally known methods. The coating method is not limited thereto, and for example, coating can be performed by spraying, dipping, or by using a bar coater, a roll coater, a gravure coater, or the like. Furthermore, the drying or heating treatment can be performed by oven drying (heating), infrared heating, high-frequency heating, vacuum drying, superheated water vapor, or the like. Example

[0058] The present invention is further described by the following examples, but the present invention is not limited by the following examples. It should be noted that various measurement methods and evaluation methods of the examples and comparative examples are as follows.

[0059] (Example 1) [Preparation of gas barrier coating composition] As a gas barrier coating composition (hereinafter referred to as "gas barrier coating"), zirconium oxide sol (Zirconium oxide sol ZSL-00120B (crystalline zirconium oxide, tetragonal system, solid content (converted as ZrO2) = 20%) manufactured by Daiichi Kizenso Kagaku Kogyo Co., Ltd.) was used as a metal oxide. First, the zirconium oxide sol was prepared using water and isopropanol solvents so as to have a solid content of 6.9% and a water / isopropanol ratio of 80 / 20. Then, 8.5 parts by mass of aluminum hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53.5 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphoric acid compound were added to 100 parts by mass of the solid content of the zirconium oxide sol, and the mixture was stirred for a predetermined time to obtain a barrier coating coating.

[0060] [Method for producing gas barrier laminate] A gas barrier laminate was prepared using the prepared barrier coating material as follows: A 12 μm thick biaxially stretched polyester film (LUMIRROR P60 manufactured by Toray Film Processing Co., Ltd.) was coated with a bar coater at a coating amount of 2.0 g / m 2 The barrier coating material was applied in a manner of , and heated and dried at 200° C. for 2 minutes in a box oven to obtain a gas barrier laminate.

[0061] [Method for preparing samples for evaluation of gas barrier properties, etc.] The samples for evaluating gas barrier properties (hereinafter referred to as "evaluation samples") were prepared as follows: the barrier coating surface of the gas barrier laminate was coated with a bar coater at a coating amount of 4.0 g / m 2A polyurethane adhesive (TAKENATE A-315 / TAKENATE A-50 manufactured by Mitsui Chemicals) was applied and dried using a dryer, and then laminated on a 50 μm thick cast polypropylene film (Torayfan ZK401 manufactured by Toray Film Processing Co., Ltd.).

[0062] (Example 2) In Example 1, with respect to 100 parts by mass of the solid content of the zirconium oxide sol, 4.4 parts by mass of aluminum hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53.3 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphoric acid compound were added in terms of the non-volatile component of phosphoric acid, and after the barrier coating was applied on the substrate, it was heated and dried in a box oven at a temperature of 220°C for 2 minutes. Except for this, a gas barrier laminate and an evaluation sample were obtained by the same method as in Example 1.

[0063] (Example 3) In Example 1, a gas barrier laminate and an evaluation sample were obtained in the same manner as in Example 1 except that the barrier coating material was applied on the substrate and then dried by heating at 220° C. for 10 minutes in a box oven.

[0064] (Example 4) As a barrier coating material, water and isopropyl alcohol solvents were used for zirconium oxide sol, and the solid content was prepared to be 3.7% and the water / isopropyl alcohol ratio was 60 / 40. Next, 44.7 parts by mass of aluminum isopropylate (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53.5 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphoric acid compound were added to 100 parts by mass of the solid content of the zirconium oxide sol, and the mixture was stirred for a predetermined time to obtain a barrier coating material. A gas barrier layered product and an evaluation sample were obtained in the same manner as in Example 1 except that the barrier coating material was applied on the substrate and then heated and dried in a box oven at 180° C. for 2 minutes.

[0065] (Example 5) In Example 4, with respect to 100 parts by mass of the solid content of the zirconium oxide sol, 48.9 parts by mass of aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53.3 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphoric acid compound were added in terms of the non-volatile component of phosphoric acid, and after the barrier coating was applied on the substrate, it was heated and dried at a temperature of 220°C for 2 minutes in a box oven. Except for this, a gas barrier laminate and an evaluation sample were obtained by the same method as in Example 1.

[0066] (Example 6) In Example 5, with respect to 100 parts by mass of the solid content of the zirconium oxide sol, 44.6 parts by mass of aluminum isopropoxide (produced by Wako Pure Chemical Industries, Ltd.) as an additive and 63.9 parts by mass of phosphoric acid (produced by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphate compound were added in an amount of non-volatile components of phosphoric acid. Except for this, a gas barrier laminate and an evaluation sample were obtained by the same method as in Example 5.

[0067] (Example 7) In Example 4, a gas barrier laminate and an evaluation sample were obtained by the same method as in Example 4, except that heat drying was performed at 220° C. for 10 minutes using a box oven.

[0068] (Comparative Example 1) A gas barrier layered product and an evaluation sample were obtained by the same method as in Example 3 except that aluminum hydroxide was not added as an additive.

[0069] (Comparative Example 2) As a barrier coating material, water and isopropanol solvents were used to prepare a solid content of 6.9% and a water / isopropanol ratio of 80 / 20 relative to the zirconium oxide sol. Next, 29.3 parts by mass of aluminum glycinate (manufactured by Tokyo Chemical Industry Co., Ltd.) as an additive and 52.0 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphoric acid compound were added to 100 parts by mass of the solid content of the zirconium oxide sol, and the mixture was stirred for a predetermined time to obtain a barrier coating material. A gas barrier layered product and an evaluation sample were obtained in the same manner as in Example 1 except that the barrier coating material was applied on the substrate and then heated and dried in a box oven at 180° C. for 2 minutes.

[0070] (Comparative Example 3) In Comparative Example 2, a gas barrier laminate and an evaluation sample were obtained by the same method as in Comparative Example 2, except that heat drying was performed at 220° C. for 10 minutes using a box oven.

[0071] (Evaluation method) The evaluation results of the gas barrier laminate and the evaluation samples were obtained as shown in Tables 1 and 2 using the following evaluation methods.

[0072] [Oxygen permeability] The oxygen transmission rate of each evaluation sample obtained in the examples and comparative examples was measured using an oxygen transmission rate measuring device (OX-TRAN 2 / 21, manufactured by Modern Control). The measurement conditions were set at a temperature of 40°C and a relative humidity of 90%.

[0073] [Water vapor transmission rate] The water vapor transmission rate of each gas barrier property evaluation sample obtained in the examples and comparative examples was measured using a water vapor transmission rate measuring device (PERMATRAN-W3 / 31, manufactured by Modern Control). The measurement conditions were set at a temperature of 40°C and a relative humidity of 90%.

[0074] [Infrared absorption spectrum] Regarding each gas barrier laminate obtained in the examples and comparative examples, the infrared absorption spectrum of the gas barrier coating film coated on the polyester substrate was measured using a Fourier transform infrared spectrophotometer (FT / IR-6600, manufactured by JASCO Corporation). [Measurement conditions of FT-IR device] Instrument used: FT / IR-6600 manufactured by JASCO. Measurement conditions: Method ATR (Ge prism). Detector: TGS. Extension: Thunder Dome. Wavenumber range: 800 - 1400 cm -1 . Film measurement surface: Gas barrier coating film surface.

[0075] [Optical properties] Regarding each gas barrier laminate obtained in the examples and comparative examples, with the detector side of the measurement being the polyester film substrate side, the total light transmittance (%) and haze (%) were measured using a computer colorimeter (SM-4, manufactured by Suga Test Instruments Co., Ltd.).

[0076] [Color measurement] Regarding each gas barrier laminate obtained in the examples and comparative examples, with the detector side of the measurement being the polyester film substrate side, the yellowness (b* value) in color measurement (CIE 1976 L*a*b* colorimetric system) was measured using a computer colorimeter (SM-4, manufactured by Suga Test Instruments Co., Ltd.).

[0077] [Fluorescent X-ray evaluation] As a method for evaluating the elements contained in each gas barrier layered product obtained in the examples and comparative examples, phosphorus, aluminum, and zirconium can be quantified using a commercially available fluorescent X-ray analyzer. The layer strength obtained in the measurement of each gas barrier layered product is defined as P / Zr for P and Zr and Al / Zr for Al and Zr, and the content ratio of each element in the coating film is calculated and used for evaluation. <Measurement Conditions of Fluorescence X-ray Analyzer> Instrument used: ZSX Primus II manufactured by Rigaku Co., Ltd. Measurement conditions: Measurement object P-Kα ray, Al-Kα ray, Zr-Kα rays. Measuring diameter: 10 mm. Measure X-ray Rh (4.0kw). The film measurement surface is measured by irradiating X-rays from the barrier coating film surface side.

[0078] Tables 1 and 2 show various measurement and evaluation results of the above-mentioned Examples and Comparative Examples.

[0079] [Table 1]

[0080] [Table 2]

[0081] [Abbreviations in Tables 1 and 2] NV: solid content of metal oxide in metal oxide sol, ZSL-00120B: crystalline zirconium oxide, TT: total light transmittance, Hz: haze, P / Zr: content ratio of phosphorus element (P) derived from phosphate compound in gas barrier laminate to zirconium element (Zr) in metal oxide, Al / Zr: content ratio of aluminum element (Al) derived from additive in gas barrier laminate to zirconium element (Zr) in metal oxide.

[0082] In Table 2, “-” means “not implemented”. Industrial Applicability

[0083] The gas barrier coating composition of the present invention can form a coating film having excellent oxygen barrier properties and water vapor barrier properties, and further has reduced yellowness, and can be preferably used as a transparent high-barrier packaging material. Description of Reference Numerals

[0084] 1: substrate; 2: adhesion-promoting coating; 3: gas barrier layer; 4: adhesive layer; 5: moisture-resistant resin layer.

Claims

1. A gas barrier coating composition, characterized in that: The invention contains: at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide; a metal oxide; and a phosphoric acid compound or a sulfuric acid compound.

2. The gas barrier coating composition according to claim 1, wherein The metal species of the metal alkoxide and the metal hydroxide is at least one of aluminum, titanium, iron and zirconium.

3. The gas barrier coating composition according to claim 1 or 2, wherein The metal alkoxide is at least one of methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide and tert-butoxide.

4. The gas barrier coating composition according to claim 1 or 2, wherein The metal alkoxide is aluminum isopropoxide.

5. The gas barrier coating composition according to claim 1 or 2, wherein The metal hydroxide is aluminum hydroxide.

6. The gas barrier coating composition according to claim 1 or 2, wherein The metal oxide is zirconium oxide or aluminum oxide.

7. The gas barrier coating composition according to claim 1 or 2, wherein The phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid and cyclic polyphosphoric acid.

8. A gas barrier laminate, characterized in that: The gas barrier laminate is a gas barrier laminate having a coating film formed from the gas barrier coating composition according to claim 1 or 2 on a substrate, The coating film is formed of a reaction product obtained by reacting at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, and a metal hydroxide, a metal oxide, and a phosphoric acid compound or a sulfuric acid compound.

9. The gas barrier laminate according to claim 8, wherein The coating film has a b* value of less than 2.2 obtained by color measurement.

10. The gas barrier laminate according to claim 8, wherein The value of Al / Zr, which is a content ratio of Zr under Zr-kα and Al under Al-kα in fluorescent X-ray measurement of the coating film, is in the range of 0.06 to 0.

35.

11. The gas barrier laminate according to claim 8, wherein The value of P / Zr, which is a content ratio of Zr at Zr-kα and P at P-kα in fluorescent X-ray measurement of the coating film, is in the range of 1.30 to 1.

82.

12. The gas barrier laminate according to claim 8, wherein An adhesion-promoting coating is provided between the substrate and the coating film.

13. The gas barrier laminate according to claim 8, wherein The substrate is formed of a 12 μm thick biaxially stretched polyester, and a coating of 2.0 g / m 2 The coating film, when a 50 μm thick cast polypropylene film is arranged on the coating film via an adhesive layer, has an oxygen permeability of 25 cc / m at 40° C. and 90% RH. 2 ·day·atm or less, and the water vapor permeability is 5.5g / m at 40℃90%RH 2 · Below the day.

Images