JP2014061681A - Gas barrier package bag and method for producing gas barrier package body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier package bag for evacuating or deaerating, and thereby packaging a content such as solid food to be heat-treated, in which the gas barrier package bag shows no degradation in the gas barrier property even when the bag is heat-treated.SOLUTION: In a gas barrier package bag for evacuating or deaerating, and thereby packaging a solid object to be heat-treated, such a laminate is used that is produced by laminating at least a substrate layer, a gas barrier layer and a sealant layer. The gas barrier layer is composed of an inorganic oxide vapor deposition layer and a coating layer. The coating layer is composed of the following layers successively laminated: a first layer formed of a mixture of a polycarboxylic acid-based polymer and at least one silicon-containing compound comprising a silane coupling agent expressed by chemical formula of RSi(OR)or its hydrolyzed product and their condensates; and a second layer containing a polyvalent metal compound.

Description

  The present invention relates to a gas barrier packaging bag for packaging contents to be subjected to solid heat treatment such as prepared foods such as boiled beans and sweet corn. In particular, the present invention relates to a gas barrier packaging bag that is packaged by vacuum or degassing.

  Conventionally, packaged foods that package prepared foods such as boiled beans, solid boiled foods such as sweet corn, and retort foods are typified by ethylene-vinyl alcohol copolymers using a gas barrier polymer as a gas barrier layer. A polymer containing a highly hydrophilic group having high hydrophilicity in the molecule has been used.

  However, these polymers have very good gas barrier properties such as oxygen under dry conditions, but greatly deteriorate in gas barrier properties such as oxygen due to their hydrophilicity under high humidity conditions. There was a problem to do. Therefore, when boil sterilization or retort sterilization is performed, there is a problem that it takes a long time to recover the gas barrier property after the sterilization treatment.

  In order to solve such problems, a multilayer sheet or a multilayer preform including at least one layer composed of a mixture of a polycarboxylic acid polymer and a plasticizer and a layer composed of a mixture of a polyvalent metal compound and a resin is stretched in the area. There has been disclosed a stretch-molded multilayer container that is stretch-molded in a range of a magnification of 1.1 to 100 (Patent Document 1).

  A layered product comprising a layer (a) comprising a composition of a polycarboxylic acid polymer and a plasticizer, a layer (c) comprising a polyvalent metal compound and a layer (b) comprising a thermoplastic resin, A stretched laminated film in which (a) and the layer (c) have at least one adjacent layer constitutional unit, and at least the layer (a) and the layer (b) are each stretched to an area stretch ratio of 1.1 to 100 Is disclosed (Patent Document 2).

  However, in the stretch-molded multilayer container or stretched laminated film as described in Patent Documents 1 and 2 above, when the multilayer sheet or the like is stored for a long period of time and then subjected to molding processing such as vacuum molding, it is sufficient. There was a problem that a container having a good gas barrier property could not be obtained. For this purpose, it is necessary to quickly perform a forming process such as vacuum forming after producing a multilayer sheet or the like, and there is a problem that the manufacturing process of the container is limited.

  In order to improve these, a draw-forming laminate comprising an unstretched support, a gas barrier multilayer film and a layer made of a thermoplastic resin, a layer containing a polycarboxylic acid polymer and a polyvalent metal compound are added. Although it has been proposed to provide a specific layer between the contained layers, the barrier property is still not sufficient (Patent Document 3).

International Publication No. WO2005 / 032813 JP 2005-125574 A JP 2008-80533 A

  An object of the present invention is to provide a gas barrier packaging bag in which contents such as solid food to be heat-treated are vacuumed or degassed and packaged so that the gas barrier property does not deteriorate even when heat-treated.

  In order to solve the above-mentioned problems, the inventors have conducted intensive studies and completed the present invention.

The invention according to claim 1 of the present invention is a gas barrier packaging bag for packaging a solid article to be heat-treated by vacuuming or degassing,
At least a gas barrier packaging bag using a laminate in which a base material layer made of a heat-resistant plastic film, a gas barrier layer, and a sealant layer are laminated,
The gas barrier layer comprises an inorganic oxide vapor deposition layer and a coating layer,
The coating layer comprises a polycarboxylic acid polymer and at least one silicon-containing compound comprising a silane coupling agent represented by the chemical formula R ¹ Si (OR ² ) ₃ or a hydrolyzate thereof and a condensate thereof. A gas barrier packaging bag, wherein a mixed first layer and a second layer having a polyvalent metal compound are sequentially laminated.

  The invention according to claim 2 of the present invention is the gas barrier packaging bag according to claim 1, wherein the heat treatment is boil sterilization or retort sterilization.

  The invention according to claim 3 of the present invention is the gas barrier packaging bag according to claim 1 or 2, wherein the inorganic oxide deposition layer is silicon oxide or aluminum oxide.

  The invention according to claim 4 of the present invention is a gas barrier property in which the gas barrier packaging bag according to any one of claims 1 to 3 is filled or sealed by vacuuming or degassing the contents and then subjected to heat treatment. It is a manufacturing method of a package.

  The gas barrier packaging bag of the present invention comprises a laminate having an inorganic oxide vapor deposition layer / coating layer as a gas barrier layer, and is packaged by vacuuming or degassing the contents of a solid food to be heat-treated. It is a bag. Even if heat treatment such as boil sterilization or retort sterilization is performed, the packaging bag can stably maintain high gas barrier properties.

According to claim 1 of the present invention, even when a fine crack is generated in the inorganic oxide deposited layer when the contents such as solid food are packaged by vacuuming or degassing, the top of the inorganic oxide deposited layer is removed. A coating layer of a polycarboxylic acid polymer and at least one silicon-containing compound comprising a silane coupling agent represented by the chemical formula R ¹ Si (OR ² ) ₃ or a hydrolyzate thereof and a condensate thereof. By comprising a laminated first layer and a second layer having a polyvalent metal compound, the deterioration of gas barrier properties can be recovered by heat from heat treatment.

  According to claim 2 of the present invention, the heat treatment is boil sterilization or retort sterilization, whereby the gas barrier property can be recovered by these heats.

  According to claim 3 of the present invention, since the inorganic oxide vapor deposition layer is made of silicon oxide or aluminum oxide, it can have transparency and gas barrier properties similar to those of aluminum foil even after heat sterilization.

  According to claim 4 of the present invention, the gas barrier packaging bag according to any one of claims 1 to 3 is filled or sealed by vacuuming or degassing the contents, and then heat-treated, so that it is high. A gas barrier package having gas barrier properties can be obtained.

It is sectional drawing which shows an example of the laminated constitution of the laminated body of this invention. It is explanatory drawing which shows an example by which the solid foodstuff is vacuum-packed in the gas barrier packaging bag of this invention.

  Embodiments of the present invention will be described below.

FIG. 1 is a cross-sectional view showing an example of the layer structure of the laminate of the present invention. The laminate 1 is formed by sequentially laminating a gas barrier layer 3 and a sealant layer 4 on a base material layer 2 made of a heat-resistant plastic film. In the gas barrier layer 3, an inorganic oxide vapor deposition layer 5 and a multi-layer 6 are sequentially formed. The coating layer 6 includes at least one silicon-containing compound (hereinafter referred to as “polycarboxylic acid polymer 9”) and a silane coupling agent represented by the chemical formula R ¹ Si (OR ² ) ₃ or a hydrolyzate thereof and a condensate thereof. , Silicon compound 10) and a second layer 8 having a polyvalent metal compound 11 are laminated.

  In the present invention, when the contents are subjected to heat treatment such as boil sterilization or retort sterilization, the polyvalent metal compound 11 in which the carboxy group of the polycarboxylic acid polymer 9 included in the first layer 7 is included in the second layer 8. Reacts with polyvalent metal ions to form ionic crosslinks. Thereby, the gas barrier performance of the first layer is significantly improved. Therefore, when packaging the contents such as solid foods by vacuuming or degassing, even if fine cracks occur in the inorganic oxide vapor deposition layer due to the unevenness or outer shape of the contents, after filling and sealing the contents The gas barrier property can be recovered by heat at the time of heat treatment.

  FIG. 2 is an explanatory view showing an example in which solid food is vacuum-packed in the gas barrier packaging bag of the present invention. When the solid food 20 is packaged in a vacuum, the laminate may be stretched due to the unevenness and shape of the food, and fine cracks may be generated in the inorganic oxide vapor-deposited layer, thereby reducing the gas barrier property. However, by providing the coating layer shown in FIG. 1, the gas barrier property can be recovered by the heat of boil sterilization or retort sterilization. Even after boil sterilization or retort sterilization, a gas barrier packaging bag 30 having high gas barrier properties is obtained.

  The embodiment of the present invention will be described in more detail.

  As the inorganic oxide forming the inorganic oxide vapor deposition layer, an inorganic oxide imparting oxygen barrier properties can be appropriately selected. Examples thereof include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. Among these, aluminum oxide, silicon oxide, magnesium oxide, or a mixture of any two or more thereof is preferable because of transparency and excellent oxygen barrier properties. These inorganic oxides can be deposited to form an inorganic oxide deposition layer.

  The thickness of the inorganic oxide vapor deposition layer is preferably within a range of 5 to 100 nm, and more preferably within a range of 10 to 50 nm. If the thickness is less than 5 nm, a uniform thin film cannot be formed, and the gas barrier function cannot be sufficiently achieved. On the other hand, when the thickness exceeds 100 nm, the flexibility is lowered, and there is a possibility that cracks may occur due to external factors such as bending and pulling after film formation.

Next, with the polycarboxylic acid polymer forming the first layer, a part of the carboxy group is previously neutralized with a basic compound, and the polymer has two or more carboxy groups in the molecule. Is. For example, (co) polymer of ethylenically unsaturated carboxylic acid, copolymer of ethylenically unsaturated carboxylic acid and other ethylenically unsaturated monomers, carboxy group in the molecule such as alginic acid, carboxymethylcellulose, pectin, etc. And acidic polysaccharides having

  The ethylenically unsaturated carboxylic acid includes a structural unit derived from at least one polymerizable monomer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid and crotonic acid. Also included are polymers.

  Examples of the ethylenically unsaturated monomer copolymerizable with the ethylenically unsaturated carboxylic acid include saturated carboxylic acid vinyl esters such as ethylene, propylene, and vinyl acetate, alkyl acrylates, alkyl methacrylates, and alkyl itaconates. , Vinyl chloride, vinylidene chloride, styrene, acrylamide, acrylonitrile and the like. These polycarboxylic acid polymers may be used alone or in combination of two or more.

  As the polycarboxylic acid polymer, among the above, from the viewpoint of the obtained gas barrier properties, at least one polymer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid and crotonic acid A polymer including a structural unit derived from a monomer is preferable, and includes a structural unit derived from at least one polymerizable monomer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid and itaconic acid. Polymers are particularly preferred.

  In the polymer, the proportion of structural units derived from at least one polymerizable monomer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid and itaconic acid is 80 mol% or more. And more preferably 90 mol% or more (however, the total of all the structural units constituting the polymer is 100 mol%). The polymer may be a homopolymer or a copolymer. When the polymer is a copolymer containing other structural units other than the above structural units, the other structural units include, for example, an ethylenically unsaturated monomer that is copolymerizable with the aforementioned ethylenically unsaturated carboxylic acid. Examples include structural units derived from the body.

  The number average molecular weight of the polycarboxylic acid polymer is preferably in the range of 2,000 to 10,000,000, more preferably 5,000 to 1,000,000. When the number average molecular weight is less than 2,000, the obtained gas barrier laminate cannot achieve sufficient water resistance, and the gas barrier property and transparency may deteriorate due to moisture, or whitening may occur. When the number average molecular weight exceeds 10,000,000, when the first layer is formed by coating, the viscosity becomes high and coating properties may be impaired. In addition, the said number average molecular weight is a number average molecular weight of polystyrene conversion calculated | required by the gel permeation chromatography (GPC).

  In the polycarboxylic acid polymer, a part of the carboxy group is previously neutralized with a basic compound. By neutralizing a part of the carboxy group of the polycarboxylic acid polymer in advance, the water resistance and heat resistance of the laminate can be further improved.

  The basic compound is preferably at least one basic compound selected from the group consisting of polyvalent metal compounds, monovalent metal compounds and ammonia.

  Examples of the polyvalent metal compound include the same polyvalent metal compounds as will be described later in the description of the second layer, and examples thereof include zinc oxide, calcium carbonate, and sodium carbonate. Examples of the basic compound that is a monovalent metal compound include sodium hydroxide and potassium hydroxide.

As the degree of neutralization of the carboxy group, when the first layer is formed by coating consisting of a coating liquid in which a polycarboxylic acid polymer and a silicon compound are mixed, the coating properties and coating stability of the coating liquid are improved. From the viewpoint, it is preferably 30 mol% or less, and more preferably 25 mol% or less. A polycarboxylic acid type polymer may be used individually by 1 type, and 2 or more types may be mixed and used for it.

Moreover, even if the silicon compound which forms a 1st layer is small quantity, it can improve the adhesiveness of an inorganic oxide vapor deposition layer and a 1st layer, and can improve heat resistance, water resistance, etc. The chemical formula R ¹ Si (OR ² ) ₃ represents (R ¹ is an organic group containing a glycidyloxy group or an amino group, R ² is an alkyl group, and 3 is an n number). Three R ^{2 s} may be the same or different.

In the chemical formula, examples of the organic group in R ¹ include a glycidyloxyalkyl group and an aminoalkyl group. As the alkyl group for R ² , an alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group or an ethyl group is particularly preferable. Specific examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and the like. Among these, γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltrimethoxysilane are preferable.

The silicon compound may be a silane coupling agent itself, a hydrolyzate obtained by hydrolysis of the silane coupling agent, or a condensate thereof. Examples of the hydrolyzate include those in which at least one of the three OR ^{2 in} the chemical formula is OH. Examples of the condensate include those in which Si—OH of at least two molecules of hydrolyzate is condensed to form a Si—O—Si bond. Hereinafter, a product obtained by condensing a hydrolyzate of a silane coupling agent is referred to as a hydrolyzed condensate.

  Further, for example, a silane coupling agent hydrolyzed and condensed by using a sol-gel method can be used. Usually, a silane coupling agent is easily hydrolyzed and a condensation reaction easily occurs in the presence of an acid or an alkali. Therefore, only a silane coupling agent, its hydrolyzate, or only a condensate thereof is used. It is rare to exist. That is, usually, a silane coupling agent, a hydrolyzate thereof, and a condensate thereof are mixed. The hydrolyzate includes a partial hydrolyzate and a complete hydrolyzate.

  The silicon compound preferably contains at least a hydrolysis condensate. As a method for producing the hydrolysis-condensation product, a silane coupling agent may be directly mixed with a liquid containing a polycarboxylic acid polymer and water, and water is added to the silane coupling agent to add water. Hydrolysis condensate may be obtained before performing decomposition and subsequent condensation reaction and mixing with the polycarboxylic acid polymer.

  Next, various additives may be included in the first layer. Examples of the additive include a plasticizer, a resin, a dispersant, a surfactant, a softener, a stabilizer, an antiblocking agent, a film forming agent, an adhesive, and an oxygen absorber.

  As a plasticizer, it can be used by appropriately selecting from known plasticizers. For example, ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, 1,3-butanediol, 2,3-butanediol, pentamethylene glycol, hexamethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polyvinyl alcohol, Examples thereof include an ethylene-vinyl alcohol copolymer, polyethylene oxide, sorbitol, mannitol, dulcitol, erythritol, glycerin, lactic acid, fatty acid, starch, and phthalate ester. These may be used in a mixture as required. Among these, polyethylene glycol, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, glycerin, and starch are preferable from the viewpoints of stretchability and gas barrier properties. When such a plasticizer is included, the stretchability of the gas barrier layer precursor is improved, so that the abuse resistance of the gas barrier precursor laminate can be further improved.

  Moreover, when the compound which has two or more hydroxyl groups, such as polyvinyl alcohol, is included as an additive, the hydroxyl group of this compound and some carboxy groups of a polycarboxylic acid-type polymer may form an ester bond.

  When the additive is contained in the first layer, the mass ratio of the polycarboxylic acid polymer to the additive is usually in the range of (70:30) to (99.9: 0.1). Yes, and preferably (80:20) to (98: 2).

  The thickness of the first layer is preferably in the range of 0.01 to 5 μm, more preferably in the range of 0.02 to 3 μm, and still more preferably in the range of 0.04 to 1.2 μm, from the viewpoint of gas barrier properties. It is a range.

  The first layer can usually be formed by a coating method using a coating liquid. It can select suitably from well-known coating methods, for example, a roll coat method, a gravure coat method, a screen coat method, a reverse coat method, a spray coat method, a die coat method, a curtain coat method etc. can be used.

  The solvent used in the coating solution is not particularly limited as long as it can dissolve the polycarboxylic acid polymer and the silicon compound, but usually water for performing the hydrolysis reaction of the silane coupling agent is necessary. Therefore, water or a mixed solvent of water and an organic solvent is preferable. Water is most preferable in terms of solubility and cost of the polycarboxylic acid polymer. An organic solvent such as alcohol is preferable in terms of improving the solubility of the silane coupling agent and the coating property of the coating liquid. As the water, purified water is preferable. For example, distilled water, ion-exchanged water or the like can be used.

  As the organic solvent, it is preferable to use at least one organic solvent selected from the group consisting of alcohols having 1 to 5 carbon atoms and ketones having 3 to 5 carbon atoms. Specific examples of such an organic solvent include methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, acetone, and methyl ethyl ketone. As a mixed solvent of water and an organic solvent, the above-mentioned mixed solvent of water and an organic solvent is preferable, and a mixed solvent of water and an alcohol having 1 to 5 carbon atoms is more preferable. As a mixed solvent, water is present in an amount of 20 to 95% by mass, and an organic solvent is present in an amount of 80 to 5% by mass (provided that the total of water and the organic solvent is 100% by weight). preferable.

  Next, the second layer is formed from a polyvalent metal compound. The polyvalent metal compound is a compound of a polyvalent metal having a metal ion valence of 2 or more. Examples of the polyvalent metal include alkaline earth metals such as beryllium, magnesium and calcium; transition metals such as titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper and zinc; aluminum and silicon. From the viewpoints of heat resistance, water resistance and transparency, calcium or zinc is particularly preferable.

Examples of the polyvalent metal compound include a simple substance of polyvalent metal, oxide, hydroxide, carbonate, organic acid salt (for example, acetate) or inorganic acid salt, ammonium complex of polyvalent metal oxide, Quaternary amine complexes or their carbonates or organic acid salts are mentioned. Among these polyvalent metal compounds, from the viewpoint of gas barrier properties, resistance to high-temperature steam and hot water, and productivity, alkaline earth metals, cobalt, nickel, copper, zinc, aluminum or silicon oxides, hydroxides, Preference is given to using chlorides, carbonates or acetates, ammonium complexes of copper or zinc or their carbonates. Among these, zinc oxide, aluminum oxide, calcium hydroxide, calcium carbonate, zinc acetate, and calcium acetate are preferable from the viewpoint of industrial productivity, and zinc oxide or calcium carbonate is particularly preferable.

  When forming the second layer from a coating liquid containing a polyvalent metal compound, the polyvalent metal compound may be in the form of particles, non-particulates, or dissolved, but dispersed From the viewpoint of productivity, productivity, and gas barrier properties, it is preferably particulate. The average particle size of the particles is not particularly limited, but from the viewpoint of coating suitability and gas barrier properties, the average particle size is preferably 5 μm or less, more preferably 1 μm or less, and 0.1 μm or less. It is particularly preferred.

  If necessary, the second layer may contain various additives in addition to the polyvalent metal compound as long as the effects of the present invention are not impaired. Examples of additives include resins that are soluble or dispersible in the solvent used in the coating liquid, dispersants that are soluble or dispersible in the solvent, surfactants, softeners, stabilizers, film forming agents, and thickeners. Etc. may be contained.

  Examples of the resin include alkyd resin, melamine resin, acrylic resin, urethane resin, polyester resin, phenol resin, amino resin, fluororesin, epoxy resin, and isocyanate resin. Thereby, the applicability | paintability and film forming property of a coating liquid improve.

  As the dispersant, an anionic surfactant or a nonionic surfactant can be used. The surfactant includes (poly) carboxylate, alkyl sulfate ester, alkylbenzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfosuccinate, alkyl diphenyl ether disulfonate, alkyl phosphate, aromatic Phosphate ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ester, alkylallyl sulfate ester salt, polyoxyethylene alkyl phosphate ester, sorbitan alkyl ester, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid Ester, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan alkyl ester, polyoxyethylene alkyl allyl ether, polyoxy Styrene derivatives, polyoxyethylene sorbitol fatty acid esters, polyoxy fatty acid esters, various surfactants such as polyoxyethylene alkyl amines. These surfactants may be used alone or in combination of two or more. Thereby, the dispersibility of a polyvalent metal compound improves.

  From the viewpoint of gas barrier properties, the thickness of the second layer is preferably in the range of 0.01 to 5 μm, more preferably in the range of 0.03 to 3 μm, and still more preferably 0.1 to 1.2 μm. It is a range.

  Examples of the method for forming the second layer include a coating method. For example, a roll coating method, a gravure coating method, a screen coating method, a reverse coating method, a spray coating method, a die coating method, a curtain coating method, or the like can be used.

  Hereinafter, a case where the second layer is formed by a coating method will be described. As the polyvalent metal compound contained in the coating liquid, the same ones as described above can be used, and a calcium compound or a zinc compound is preferable.

Examples of the solvent used for the coating liquid include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, Examples include hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. In addition, these solvents may be used alone or in combination of two or more.

  Among these, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferable from the viewpoint of coatability. From the viewpoint of productivity, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferable. Since the first layer has excellent water resistance, water can be used as a solvent used in the coating solution.

  From the viewpoint of coating suitability, the total content of the polyvalent metal compound and the additive in the coating solution is preferably in the range of 1 to 50% by mass with respect to the total weight of the coating solution, The range is more preferable, and the range of 5 to 40% by mass is particularly preferable.

  This coating solution is applied onto the first layer to form a coating film. The drying method is not particularly limited, and examples thereof include a hot air drying method, a hot roll contact method, an infrared heating method, and a microwave heating method. These methods may be used alone or in combination of two or more.

  Although there is no limitation in particular as drying temperature, When using the water mentioned above as a solvent, or the mixed solvent of water and an organic solvent, 50-160 degreeC is preferable normally. The drying pressure is usually normal pressure or reduced pressure, and it is preferably normal pressure from the viewpoint of facility simplicity.

  As a base material layer made of a plastic film having heat resistance, for example, a polyester film, a polyamide film, a polypropylene film, a polycarbonate film, or the like can be used because it becomes a base material constituting a packaging bag. A stretched film stretched in the biaxial direction is preferred. An inorganic oxide may be deposited on one surface (inner surface) of these films to provide an inorganic oxide deposition layer. The thickness of the film may be any thickness that can be held to the minimum necessary for strength, rigidity, etc. as a base material, and about 12 to 25 μm is appropriate.

  Examples of the sealant layer include low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, and ethylene-acrylic acid copolymer. , Ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, and other resins that can be melted by heat and fused together. These may be used alone or in combination of two or more, and a resin and a sheet obtained by forming them into a film may be used. As thickness, 10-150 micrometers is desirable and 30-50 micrometers is more preferable.

  In the present invention, an intermediate layer may be provided between the gas barrier layer and the sealant layer. For example, films of polyethylene terephthalate, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymer, saponified ethylene-vinyl acetate copolymer, and the like can be used. By providing these films in the intermediate layer, oxygen barrier properties, water vapor barrier properties, mechanical strength, bending resistance, puncture resistance, impact resistance, wear resistance, cold resistance, heat resistance, chemical resistance, It is possible to improve the light shielding resistance.

In the present invention, a heat-sealable member such as a plug or a chuck may be attached as necessary. Even when plugs or chucks are attached, even if fine cracks occur in the inorganic oxide deposition layer due to heat and pressure from the outside and the barrier properties are reduced, the gas barrier is affected by heat from heat treatment such as boil sterilization or retort sterilization. Sexuality can be restored.

  The gas barrier packaging body in which the gas barrier packaging bag of the present invention is filled with the contents, and subjected to heat treatment such as boil sterilization or retort sterilization after sealing can maintain high gas barrier properties.

  Hereinafter, specific examples of the present invention will be described in detail.

  On a biaxially stretched polyethylene terephthalate (PET: Toray Co., Ltd., Lumirror, thickness 12 μm) film, an isocyanate anchor coat solution was applied with a bar coater so that the thickness after drying was 0.2 μm. An anchor coat layer was formed by drying at 150 ° C. for 1 minute.

  Subsequently, the metal aluminum was evaporated onto the anchor coat surface by a vacuum vapor deposition apparatus using an electron beam heating method, oxygen gas was introduced into the anchor coat surface, and aluminum oxide was vapor deposited to form an inorganic oxide vapor deposition layer having a thickness of 20 nm.

On this inorganic oxide vapor deposition layer, after coating the coating liquid of the prescription shown below using a bar coater so that the thickness after drying might be set to 1 micrometer, it dried for 5 minutes at 80 ° C, and then 50 The first layer was formed by aging treatment at 3 ° C. for 3 days and further heat treatment at 200 ° C. for 5 minutes.
<Coating solution>
20 g of a polyacrylamide (PAA) aqueous solution having a number average molecular weight of 200,000 (Toa Gosei Co., Ltd., Aron A-10H, solid content concentration: 25% by mass) was dissolved in 58.9 g of distilled water. Thereafter, 0.44 g of aminopropyltrimethoxysilane (APTMS: Sigma Aldrich Japan Co., Ltd.) was added to prepare a uniform solution.

Next, a coating liquid having the following formulation is applied on the first layer using a bar coater so that the thickness after drying is 1 μm, and then dried at 90 ° C. for 2 minutes to be second. A layer was formed. Thus, a barrier film was obtained.
<Coating solution>
Fine particle zinc oxide dispersion (Sumitomo Osaka Cement Co., Ltd. ZS303, average particle size 0.02 μm, solid content concentration 30% by mass, dispersion solution toluene).

  Next, on the second layer, a linear short chain branched polyethylene (LLDPE: manufactured by Tosero Co., Ltd., TAF610C, thickness 25 μm) is used using an adhesive (A620 / A65 manufactured by Mitsui Chemicals, Inc.) Lamination was performed by dry lamination.

  Next, two pieces of the laminate are cut into a size of 10 cm × 10 cm, and then corn is vacuum-packed as the contents, followed by boil sterilization in a boil layer at 90 ° C. for 30 minutes to produce a gas barrier packaging bag did.

  Except for providing an unstretched nylon film (CNY: manufactured by Mitsubishi Resin Co., Ltd., Diamilon C, thickness 20 μm) between the barrier film and the LLDPE film, the gas barrier property was boil-sterilized in the same manner as in Example 1. A packaging bag was created.

  Hereinafter, comparative examples of the present invention will be described.

<Comparative Example 1>
PET film 12 μm, ethylene-vinyl alcohol copolymer (EVOH: Kuraray Co., Ltd., Eval film EF-E, thickness 20 μm), the CNY film, and the LLDPE film are laminated by a dry laminating method to form a barrier laminate film A packaging bag was made in the same manner as in Example 1 except that the above was obtained. The configuration is PET film / EVOH film / CNY film / LLDPE film. The above adhesive was also used as the adhesive.

<Comparative example 2>
Except that PET film 12μm and barrier nylon (Mitsubishi Resin Co., Ltd., MXD-6 series ONY, Super Neal, thickness 15μm) and the above LLDPE film were dry laminated by the dry laminating method to obtain a barrier laminate film. A packaging bag was prepared in the same manner as in Example 1. The configuration is PET film / barrier nylon film / LLDPE film. The above adhesive was also used as the adhesive.

<Evaluation method>
The oxygen permeability of the gas barrier packaging bags of Examples 1 and 2 and the packaging bags of Comparative Examples 1 and 2 and the oxygen gas permeability after boil sterilization were measured. Measurement conditions: Measured under the conditions of 30 ° C./70% RH using OX-TRAN 2/20 model manufactured by MOCON.

  The evaluation results are shown in Table 1.

実施例１，２のガスバリア性包装袋は、ボイル殺菌後でも酸素透過度の低下は観られない。しかし、比較例１、２では低下が観られた。本発明の効果が確認できた。

The gas barrier packaging bags of Examples 1 and 2 do not show a decrease in oxygen permeability even after boiling sterilization. However, in Comparative Examples 1 and 2, a decrease was observed. The effect of the present invention was confirmed.

DESCRIPTION OF SYMBOLS 1 Laminate 2 Base material layer 3 Gas barrier layer 4 Sealant layer 5 Inorganic oxide vapor deposition layer 6 Multilayer 7 First layer 8 Second layer 9 Polycarboxylic acid polymer 10 Silicon compound (chemical formula R ¹ Si (OR ² )) ₍₃ ) at least one silicon-containing compound comprising the silane coupling agent shown in ₃ or a hydrolyzate thereof and a condensate thereof)
11 Polyvalent metal compound 20 Solid food 30 Gas barrier packaging bag

Claims (4)

In a gas barrier packaging bag that vacuums or evacuates and packs a solid package to be heat-treated,
At least a gas barrier packaging bag using a laminate in which a base material layer made of a heat-resistant plastic film, a gas barrier layer, and a sealant layer are laminated,
The gas barrier layer comprises an inorganic oxide vapor deposition layer and a coating layer,
The coating layer comprises a polycarboxylic acid polymer and at least one silicon-containing compound comprising a silane coupling agent represented by the chemical formula R ¹ Si (OR ² ) ₃ or a hydrolyzate thereof and a condensate thereof. A gas barrier packaging bag, wherein a mixed first layer and a second layer having a polyvalent metal compound are sequentially laminated.   The gas barrier packaging bag according to claim 1, wherein the heat treatment is boil sterilization or retort sterilization.   The gas barrier packaging bag according to claim 1 or 2, wherein the inorganic oxide vapor-deposited layer is silicon oxide or aluminum oxide.   The manufacturing method of the gas-barrier packaging body which heat-processes, after filling and sealing the content in the gas-barrier packaging bag of any one of Claims 1-3 by vacuum or deaeration.

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