JP6516515B2 - Packaging bag for alcohol content - Google Patents

Description

  The present invention relates to a laminate for heat sterilization treatment which has excellent gas barrier properties even under high humidity and is excellent in alcohol resistance.

  Plastic films such as polyamide films are used in a wide range of applications as packaging materials because they are excellent in strength, transparency, and moldability. However, since these plastic films have high gas permeability such as oxygen, when used for packaging of general food, retort-treated food, cosmetics, medical supplies, agricultural chemicals, etc., oxygen permeated the film during long-term storage And other gases may cause deterioration of the contents. Therefore, plastic films used for these packaging applications are required to have gas barrier properties, and in packaging such as foods containing water, gas barrier properties under high humidity are also required.

  As a method of imparting gas barrier properties to a plastic film, there is a method of laminating a gas barrier layer on a film, and as the gas barrier layer, one comprising a polycarboxylic acid type polymer, a polyalcohol type polymer and a metal compound may be used Are known.

  For example, Patent Document 1 discloses, as a method for producing a gas barrier laminate having gas barrier properties even under high humidity, a gas barrier comprising a plastic substrate, a gas barrier layer, and a polymer layer containing a divalent or higher metal compound. A method of producing a gas barrier laminate by heat-treating the porous laminate in the presence of water is described.

Unexamined-Japanese-Patent No. 2004-322626

However, in the method of Patent Document 1, after forming the gas barrier layer, pressure treatment using an autoclave is performed in water containing a metal compound, and it is difficult to carry out continuously, and productivity is poor. It was a thing.
Further, in Patent Document 1, an undercoat layer is formed by applying and drying a solvent-based paint, and a gas barrier layer is formed thereon by applying and drying a water-based paint. Therefore, the method of Patent Document 1 has problems in terms of economy and productivity, such as the need for explosion-proof equipment to use a solvent-based paint and the need for multiple applications.

The present inventors examined simultaneously applying a solvent-based undercoat layer-forming paint and an aqueous water-based gas barrier layer-forming paint using a curtain coater or the like in the method of Patent Document 1; The coating film sometimes became uneven, and the resulting laminate did not exhibit gas barrier properties.
Also, the paint for forming the undercoat layer is replaced with a water-based one, and simultaneously applied using a curtain coater or the like, or after the water-based paint for forming the undercoat layer is applied and dried, the water-based paint for forming the gas barrier layer Although it was examined to apply the above, none of the resulting laminates exhibited gas barrier properties.

  Furthermore, when the gas barrier laminate obtained by the method of Patent Document 1 is used for a package filled with an alcohol-based content, when the package including the content is subjected to heat sterilization treatment, appearance defects occur in the package There is. The appearance defect of the package includes, for example, whitening of a part of the transparent laminate film constituting the package, and formation of blisters on the surface or inside of the laminate film. Thermal sterilization methods include hot-packing, boiling sterilization, and retort sterilization. Among them, when using the retort sterilization method with the highest heat treatment temperature, the appearance defect of the package particularly easily occurs.

  The object of the present invention is to solve the above problems, to be excellent in productivity and economy, to have excellent gas barrier properties even under high humidity, and to be used as a package filled with alcohol contents at the time of heat sterilization treatment It is an object of the present invention to provide a laminate for heat sterilization treatment in which the occurrence of appearance defects of the above is suppressed.

As a result of intensive studies on the above problems, the present inventors use a plastic base material (I) containing a specific amount of a metal compound and laminate a gas barrier layer (II) containing polycarboxylic acid thereon. However, when using as a package which has excellent gas barrier properties even under high humidity and is filled with an alcohol-based content, it has been found that the occurrence of appearance defects during heat sterilization is suppressed, and the present invention has been achieved .
That is, the gist of the present invention is as follows.
(1) A laminate obtained by laminating a gas barrier layer (II) on a plastic substrate (I), wherein the plastic substrate (I) contains 0.1 to 10% by mass of a metal compound, a gas barrier layer (II ) After treatment with hot water at 120 ° C. for 30 minutes, the oxygen permeability in an atmosphere at 20 ° C. and 65% relative humidity is at least 20 ml / (m 2 · day · MPa) and 200 ml / m 2). What is claimed is : 1. A packaging bag for an alcohol-containing material, comprising a laminate for heat sterilization treatment of (m 2 · day · MPa) or less.
(2) The packaging material for an alcohol-containing material according to (1), wherein the plastic substrate (I) is a multilayer film, and at least one layer thereof contains a metal compound in an amount of 0.1 to 10% by mass . Bag .
(3) The packaging bag for an alcohol-containing material according to (1) or (2), wherein the thermoplastic resin constituting the plastic base material (I) is a polyamide resin or a polyester resin.
(4) The packaging bag for alcohol-containing material according to any one of (1) to (3), wherein the gas barrier layer (II) contains a polyalcohol .
(5) The packaging bag for an alcohol-containing material according to any one of (1) to (4), wherein the metal constituting the metal compound is one selected from magnesium, calcium and zinc.
(6) The packaging bag for alcohol-containing material according to any one of (1) to (5), which is biaxially stretched simultaneously or sequentially.

According to the present invention, when it is used as a package that is excellent in productivity and economy, has excellent gas barrier properties even under high humidity, and is filled with an alcohol-based content, appearance defects occur during heat sterilization treatment The laminated body for heat sterilization treatment suppressed can be provided.
In the present invention, the plastic substrate containing the metal compound can be manufactured only by adding the metal compound to the raw material of the plastic substrate, and the layer including the metal compound, which has been conventionally performed, is laminated to the substrate The process can be omitted. Therefore, a laminate having gas barrier properties can be obtained with a smaller number of processes than in the past, and therefore, the industrial merit is extremely large from the viewpoint of productivity and cost. In addition, the obtained laminate has excellent gas barrier properties even under high humidity, and when used as a package filled with an alcohol-based content, the occurrence of appearance defects during heat sterilization is suppressed .

Hereinafter, the present invention will be described in detail.
The laminate for heat sterilization treatment of the present invention is obtained by laminating the gas barrier layer (II) on the plastic substrate (I), and the plastic substrate (I) needs to contain a metal compound.

  The metal constituting the metal compound may be a monovalent metal such as lithium, sodium, potassium, rubidium or cesium, or a divalent or higher metal such as magnesium, calcium, zirconium, zinc, copper, cobalt, iron, nickel or aluminum. Can be mentioned. Among them, metals having high ionization tendency are preferable from the viewpoint of easy reaction with carboxylic acid, and monovalent or divalent metals are preferable from the viewpoint of gas barrier properties. Specifically, lithium, sodium, potassium, magnesium, calcium and zinc are preferable, and magnesium, calcium and zinc are more preferable. The type of metal is not limited to one, and may be two or more.

  In the present invention, the metal compound is a compound containing the above metal, and as the compound, oxides, hydroxides, halides, inorganic salts such as carbonates, hydrogencarbonates, phosphates, sulfates and the like, And acetates, formates, stearates, citrates, malates, carboxylates such as maleates and organic acid salts such as sulfonates, preferably oxides or carbonates. . Also, a single metal may be used as the metal compound.

  Among the above-mentioned metal compounds, preferred examples are lithium carbonate, sodium hydrogencarbonate, magnesium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, magnesium acetate, calcium oxide, calcium carbonate, calcium hydroxide, calcium chloride, calcium phosphate, calcium sulfate, acetic acid Calcium, zinc acetate, zinc oxide, zinc carbonate and the like, and from the viewpoint of gas barrier properties, magnesium salts such as magnesium oxide, magnesium carbonate, magnesium hydroxide and magnesium acetate, calcium carbonate, calcium acetate, zinc oxide, Preferred are divalent metal compounds such as zinc acetate, and from the viewpoint of the transparency of the plastic substrate (I), monovalent compounds such as lithium carbonate and sodium hydrogen carbonate, magnesium oxide, magnesium carbonate and magnesium hydroxide Magnesium salts such as aluminum are preferred. These may be used alone or in combination of two or more.

  The metal compound is preferably in the form of powder, and the average particle diameter is not particularly limited, but is preferably 0.001 to 10.0 μm, more preferably 0.005 to 5.0 μm, 0 The thickness is more preferably 0.1 to 2.0 μm, and particularly preferably 0.05 to 1.0 μm. The metal compound preferably has a small average particle size because the haze of the plastic substrate (I) can be reduced. However, metal compounds having an average particle size of less than 0.001 μm tend to aggregate due to their large surface area, and coarse aggregates may be scattered in the film, which may lower the mechanical properties of the substrate. On the other hand, the plastic substrate (I) containing a metal compound having an average particle size of more than 10.0 μm tends to be broken at a high frequency during film formation, and the productivity tends to decrease.

  The metal compound can be improved in dispersibility, weatherability, wettability with a thermoplastic resin, heat resistance, transparency and the like by performing surface treatment such as inorganic treatment or organic treatment. Examples of the inorganic treatment include alumina treatment, silica treatment, titania treatment, zirconia treatment, tin oxide treatment, antimony oxide treatment, zinc oxide treatment and the like. Examples of the organic treatment include treatment with a fatty acid compound, a polyol compound such as pentaerythritol or trimethylolpropane, an amine compound such as triethanolamine or trimethylolamine, or a silicone compound such as a silicone resin or alkylchlorosilane. .

  The content of the metal compound in the plastic base material (I) needs to be 0.1 to 10% by mass, and the magnesium compound is preferably 0.1 to 2.0% by mass, and further preferably It is preferable that it is 0.1-1.0 mass%, and it is most preferable that it is 0.1-0.3 mass%. Moreover, 0.3-5 mass% of a calcium compound is preferable, and 0.3-10 mass% of a zinc compound is preferable. When the content of the metal compound is less than 0.1% by mass, the crosslinked structure formed by reaction with the polycarboxylic acid of the gas barrier layer (II) is reduced, and the resulting laminate has a reduced gas barrier property. On the other hand, when the content is more than 10% by mass, when it is used as a package filled with an alcohol-based content, appearance defects tend to occur at the time of heat sterilization treatment.

The method for containing the metal compound in the plastic base material (I) is not particularly limited, and it can be blended at any time of the production process. For example, a method of adding a metal compound when polymerizing a thermoplastic resin constituting the plastic substrate (I), a method of kneading a thermoplastic resin and a metal compound by an extruder, a high concentration of the metal compound There is a method (master batch method) of preparing a master batch kneaded and blended, adding it to a thermoplastic resin and diluting it. In the present invention, a masterbatch method is preferably employed.

In the present invention, as the thermoplastic resin constituting the plastic base material (I), polyolefin resins such as polyethylene, polypropylene and ionomer, nylon 6, nylon 66, nylon 46, nylon resin such as nylon MXD6 and nylon 9T, polyethylene terephthalate , Polyester resins such as polyethylene isophthalate, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polylactic acid, vinyl chloride, polystyrene resin, polycarbonate resin, polycarbonate resin, polyarylate resin, ethylene Vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, etc., or mixtures thereof. Among these thermoplastic resins, when a packaging bag is formed, a polyamide resin is preferable because it is excellent in piercing strength, impact resistance and the like, and nylon 6 is preferable among them. In addition, polyester resins are preferable, and polyethylene terephthalate is particularly preferable, from the viewpoints of excellent heat resistance and economical efficiency.

The thermoplastic resin may, if necessary, be a heat stabilizer, an antioxidant, a reinforcing material, a pigment, an antidegradant, a weathering agent, a flame retardant, as long as the performance of the plastic substrate (I) is not adversely affected. Various additives such as plasticizers, preservatives, UV absorbers, antistatic agents and antiblocking agents may be added singly or in combination. In addition, inorganic particles other than metal compounds and organic lubricants may be added to the thermoplastic resin for the purpose of improving the slip properties of the plastic base material (I), etc. Among them, silica may be added. preferable.

The thickness of the plastic substrate (I) can be appropriately selected according to the mechanical strength required for the obtained laminate. Plastic substrates (I) for reasons of mechanical strength and ease of handling
The thickness of is preferably 5 to 100 μm, and more preferably 10 to 30 μm. When the thickness is less than 5 μm, sufficient mechanical strength can not be obtained, and the piercing strength tends to be deteriorated.

  The plastic substrate (I) may be a single layer film or a multilayer film. When the plastic substrate (I) is a monolayer film, the metal compound needs to be contained in the monolayer film in an amount of 0.1 to 10% by mass. When it is a multilayer film, it is necessary to contain 0.1-10 mass% in the at least one layer.

  Hereinafter, the configuration of the multilayer film will be described. The layer containing the metal compound in the multilayer film is referred to as "metal-containing layer (M)", and the other layers are referred to as "resin layer (R)". When the plastic substrate (I) is a multilayer film, the gas barrier layer (II) and the metal-containing layer (M) of the plastic substrate (I) are in contact with each other as a configuration of the gas barrier film obtained. (R) / (M) / (II), (M) / (R) / (M) / (II), (II) / (M) / (R) / (M) / (II), etc. Is preferred. In these configurations, the gas barrier layer (II) and the metal-containing layer (M) are in contact with each other, and the polycarboxylic acid in the gas barrier layer (II) easily reacts with the metal compound in the metal-containing layer (M), Gas barrier properties can be obtained efficiently. Among them, the configuration of (R) / (M) / (II) is preferable in consideration of equipment for production and operability.

  The thickness component ratio of the metal-containing layer (M) and the resin layer (R) constituting the multilayer film is not particularly limited, and the total thickness (Mt) of the metal-containing layer (M) and the total of the resin layer (R) The ratio ((Rt) / (Mt)) of the thickness (Rt) is preferably 1/1/100 to 1000/1, and the thickness control of each layer is easy, so 1/100 to 100/1. It is more preferable that the ratio be 1/10 to 10/1.

  The above additives may be added to the thermoplastic resin constituting the resin layer (R), and the resin layer (R) to be the outermost layer of the laminate is made of silica or the like for the purpose of improving the slip property. It is preferable to add.

The gas barrier layer (II) constituting the laminate for heat sterilization of the present invention is required to contain a polycarboxylic acid. The polycarboxylic acid in the gas barrier layer (II) can exhibit gas barrier properties by reacting with the metal compound in the plastic substrate (I).
In addition, as mentioned later, the laminated body for heat sterilization treatments of this invention expresses the oxygen permeability of the specific range after the hot water treatment of 120 degreeC and 30 minutes. Accordingly, the gas barrier layer (II) constituting the laminate reacts with the metal compound in the plastic base material (I) after hot water treatment at 120 ° C. for 30 minutes to exhibit gas barrier properties.

The polycarboxylic acid in the present invention is a compound or polymer having two or more carboxyl groups in the molecule, and these carboxyl groups may form an anhydride structure.
Specific examples of the polycarboxylic acid include 1,2,3,4-butanetetracarboxylic acid, polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymer, acrylic acid-maleic acid copolymer, polymaleic acid Examples thereof include olefin-maleic acid copolymers such as ethylene-maleic acid copolymer, polysaccharides having a carboxyl group in a side chain such as alginic acid, polyamides having a carboxyl group, polyesters, and the like. The above polycarboxylic acids can be used alone or in combination of two or more.

  When the polycarboxylic acid is a polymer, its weight average molecular weight is preferably 1,000 to 1,000,000, and more preferably 10,000 to 150,000. More preferably, it is 110,000. When the weight average molecular weight of the polycarboxylic acid is too low, the resulting gas barrier layer (II) becomes brittle, while when the molecular weight is too high, the handling property is impaired, and in some cases, the gas barrier layer (II) described later The gas barrier layer (II) obtained by aggregating in the coating liquid for forming may lose the gas barrier properties.

In the present invention, among the above-mentioned polycarboxylic acids, polyacrylic acid and olefin-maleic acid copolymer, particularly ethylene-maleic acid copolymer (hereinafter sometimes abbreviated as EMA), from the viewpoint of gas barrier properties, It is preferably used. EMA is obtained by polymerizing maleic anhydride and ethylene by a known method such as solution radical polymerization.
The maleic acid unit in the olefin-maleic acid copolymer tends to form a maleic anhydride structure in which adjacent carboxyl groups are dehydrated and cyclized in the dry state, and opens in a wet state or in an aqueous solution to form a maleic acid structure. Therefore, in the present invention, unless otherwise specified, maleic acid units and maleic anhydride units are collectively referred to as maleic acid units.
The maleic acid unit in EMA is preferably 5 mol% or more, more preferably 20 mol% or more, still more preferably 30 mol% or more, and most preferably 35 mol% or more. .
The weight average molecular weight of EMA is preferably 1,000 to 1,000,000, more preferably 3,000 to 500,000, and 7,000 to 300,
It is more preferable that it is 000, and it is especially preferable that it is 10,000-200,000.

In the present invention, the gas barrier layer (II) preferably contains a polyalcohol. By containing a polyalcohol, the polycarboxylic acid in the gas barrier layer (II) reacts with the polyalcohol in addition to the reaction with the metal compound in the plastic substrate (I), thereby improving the gas barrier properties. be able to.
Polyalcohols are compounds having two or more hydroxyl groups in the molecule, and as low molecular weight compounds, glycerol, sugar alcohols such as pentaerythritol, monosaccharides such as glucose, disaccharides such as maltose, oligosaccharides such as galactooligosaccharides A sugar is mentioned, and polysaccharides, such as polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and starch, are mentioned as a high molecular compound. The above polyalcohols can be used alone or in combination of two or more.
The degree of saponification of the polyvinyl alcohol or ethylene-vinyl alcohol copolymer is preferably 95 mol% or more, and more preferably 98 mol% or more. The average degree of polymerization is preferably 50 to 2,000, and more preferably 200 to 1,000.

  The polycarboxylic acid and the polyalcohol in the gas barrier layer (II) are preferably contained so that the molar ratio of OH group to COOH group (OH group / COOH group) is 0.01 to 20, and 0. The content is more preferably 0.1 to 10, more preferably 0.02 to 5, and most preferably 0.04 to 2.

  Further, in the present invention, the gas barrier layer (II) preferably contains polyacrylamide, polymethacrylamide or polyamine. By containing these compounds, the polycarboxylic acid in the gas barrier layer (II) reacts with these compounds in addition to reacting with the metal compounds in the plastic substrate (I), so It can be improved.

The polyamine has two or more of at least one amino group selected from primary and secondary as an amino group in the molecule, and specific examples thereof include polyallylamine, polyvinylamine, branched polyethyleneimine And linear polyethylenimine, polylysine, polysaccharides having an amino group in a side chain such as chitosan, and polyamides having an amino group in a side chain such as polyarginine.
The weight average molecular weight of the polyamine is preferably 5,000 to 150,000. If the weight average molecular weight of the polyamine is too low, the resulting gas barrier layer (II) becomes brittle, while if the molecular weight is too high, the handling property is impaired, and in some cases, the gas barrier layer (II) described later is formed. The gas barrier layer (II) obtained by aggregating in a coating solution for the purpose may lose the gas barrier properties.

  The mass ratio of polyamine to polycarboxylic acid (polyamine / polycarboxylic acid) in the gas barrier layer (II) is preferably 12.5 / 87.5 to 27.5 / 72.5. When the mass ratio of the polyamine is lower than this, crosslinking of the carboxyl group of the polycarboxylic acid is insufficient, and conversely, when the mass ratio of the polyamine is higher than this, the crosslinking of the amino group of the polyamine becomes insufficient. Also, the resulting laminate may have inferior gas barrier properties.

The gas barrier layer (II) in the present invention may contain a crosslinking agent. The gas barrier properties can be enhanced by containing a crosslinking agent.
It is preferable that it is 0.1-30 mass parts with respect to 100 mass parts of polycarboxylic acids, and, as for content of the crosslinking agent in gas barrier layer (II), it is more preferable that it is 1-20 mass parts.
Examples of the crosslinking agent include compounds having a self-crosslinking property and compounds having a plurality of functional groups that react with carboxyl groups in the molecule, and when the gas barrier layer (II) contains a polyalcohol, it reacts with hydroxyl groups. It may be a compound having a plurality of functional groups in the molecule. Specific examples of the crosslinking agent preferably include isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, zirconium salt compounds such as ammonium zirconium carbonate, metal alkoxides, and the like. These crosslinking agents may be used in combination.

  The metal alkoxide is a compound containing a metal to which an alkoxy group is bound, and an alkyl group substituted with a functional group having reactivity with a halogen or a carboxyl group may be bound instead of a part of the alkoxy group. . Here, metals include atoms such as Si, Al, Ti, and Zr, halogens include chlorine, iodine, bromine and the like, and functional groups having reactivity with carboxyl groups are epoxy groups And an amino group, an isocyanate group and a ureido group, and the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group and the like. Examples of such compounds include tetramethoxysilane, tetraethoxysilane, chlorotriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, Alkoxysilane compounds such as 3-aminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane and 3-isocyanatopropyltriethoxysilane, alkoxytitanium compounds such as tetraisopropoxytitanium and tetraethoxytitanium, and alkoxys such as triisopropoxyaluminum Examples thereof include aluminum compounds and alkoxyzirconium compounds such as tetraisopropoxyzirconium.

  These metal alkoxides should be used in the form of partially or wholly hydrolyzed, partially hydrolyzed or condensed, completely hydrolyzed and partially condensed or a combination thereof. You can also.

  When the metal alkoxide and the polycarboxylic acid are mixed, it may be difficult for both to react and coat, so it is preferable to form a hydrolytic condensate beforehand and then to mix. As a method of forming a hydrolysis condensation product, a method used in a known sol-gel method can be applied.

In the gas barrier layer (II) in the present invention, a heat stabilizer, an antioxidant, a reinforcing material, a pigment, an antidegradant, weather resistance, as long as the gas barrier property and the adhesion with the plastic substrate (I) are not significantly impaired. Agents, flame retardants, plasticizers, mold release agents, lubricants, preservatives, antifoaming agents, wetting agents, viscosity modifiers and the like may be added.
Examples of heat stabilizers, antioxidants and antidegradants include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, halides of alkali metals and the like, and these may be mixed and used. May be
As the reinforcing material, for example, clay, talc, wollastonite, silica, alumina, calcium silicate, sodium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zeolite, montmorillonite, hydrotalcite, fluorine mica, Metal fibers, metal whiskers, ceramic whiskers, potassium titanate whiskers, boron nitride, graphite, glass fibers, carbon fibers, fullerenes (C60, C70, etc.), carbon nanotubes, etc. may be mentioned.

The thickness of the gas barrier layer (II) to be laminated on the plastic substrate (I) in the present invention is preferably thicker than 0.05 μm in order to sufficiently enhance the gas barrier properties of the laminate, and from the economical point of view It is preferable to be thinner than 5.0 μm.

The gas barrier layer (II) in the present invention can be formed by applying and drying a coating solution for forming the gas barrier layer (II) on the plastic substrate (I).
The coating liquid is preferably aqueous from the viewpoint of workability, so the polycarboxylic acid, polyalcohol or polyamine constituting the coating liquid is preferably water-soluble or water-dispersible, and is water-soluble. It is more preferable that

  In the present invention, when a polycarboxylic acid and a polyalcohol are mixed to prepare an aqueous coating solution, it is preferable to add an alkaline compound in an amount of 0.1 to 20 equivalent% to the carboxyl group of the polycarboxylic acid. . The polycarboxylic acid has high hydrophilicity when the content of the carboxyl group is large, so it can be made into an aqueous solution without adding an alkali compound. However, the gas barrier properties of the resulting laminate can be remarkably improved by adding an appropriate amount of an alkali compound. The alkali compound is only required to be capable of neutralizing the carboxyl group of the polycarboxylic acid, and among them, alkali compounds of monovalent metals and ammonia are preferable, and as alkali compounds of monovalent metals, potassium hydroxide and sodium hydroxide are preferable. More preferable. It is preferable that these addition amounts are 0.1-20 mol% with respect to the carboxyl group of polycarboxylic acid.

  The preparation of the coating solution can be carried out by a known method using a dissolver equipped with a stirrer, etc. For example, the polycarboxylic acid and the polyalcohol are separately made into an aqueous solution and mixed before coating The method is preferred. At this time, if the above alkali compound is added to the aqueous solution of polycarboxylic acid, the stability of the aqueous solution can be improved.

  Further, in the present invention, when an aqueous coating liquid is prepared by mixing a polycarboxylic acid and a polyamine, in order to suppress gelation, it is preferable to add a base to the polycarboxylic acid. The base may be any base that does not inhibit the gas barrier properties of the resulting laminate, and examples thereof include inorganic substances such as sodium hydroxide and calcium hydroxide, and organic substances such as ammonia, methylamine and diethanolamine. Ammonia is preferable because it is easily volatilized. The amount of the base added is preferably 0.6 equivalents or more, more preferably 0.7 equivalents or more, and more preferably 0.8 equivalents or more with respect to the carboxyl group of the polycarboxylic acid. preferable. When the amount of the base added is small, the coating liquid may gel during coating, and it may be difficult to form the gas barrier layer (II) on the plastic substrate (I).

The method for applying the coating liquid for forming the gas barrier layer (II) to the plastic substrate (I) is not particularly limited, and an air knife coater, kiss roll coater, metering bar coater, gravure roll coater, reverse roll coater, dip coater A die coater or the like, or a combination of these can be used.

After the coating liquid for forming the gas barrier layer (II) is applied to the plastic substrate (I), heat treatment may be carried out immediately to form a dry film and heat treatment simultaneously, or after application, hot air with a dryer or the like After forming a dry film by evaporating water or the like by spraying or infrared irradiation, the heat treatment may be performed. It is preferable to carry out heat treatment immediately after coating, as long as there is no particular hindrance to physical properties such as the state of the gas barrier layer (II) and the gas barrier property.
The heat treatment method is not particularly limited, and examples thereof include a method of heat treatment in a dry atmosphere such as an oven. In consideration of shortening of the process and the like, it is preferable to stretch the plastic substrate (I) after applying the coating liquid for forming the gas barrier layer (II).
In any of the above cases, the plastic substrate (I) on which the gas barrier layer (II) is formed
C.) in a heating atmosphere at 100.degree. C. or more for 5 minutes or less.

In the case where the gas barrier layer (II) contains a polycarboxylic acid and a polyalcohol, the gas barrier layer (II) can also be affected by the ratio thereof, the presence or absence of added components, and the content thereof. Although the heat processing temperature can not generally be said, it is preferable that it is 100-300 degreeC, It is more preferable that it is 120-250 degreeC, It is more preferable that it is 140-240 degreeC, It is 160-220 degreeC Is particularly preferred. If the heat treatment temperature is too low, the cross-linking reaction of the polycarboxylic acid and the polyalcohol can not proceed sufficiently, which may make it difficult to obtain a laminate having sufficient gas barrier properties, while being too high. And the gas barrier layer (II) may become brittle.
The heat treatment time is preferably 5 minutes or less, more preferably 1 second to 5 minutes, still more preferably 3 seconds to 2 minutes, and particularly preferably 5 seconds to 1 minute . If the heat treatment time is too short, the above-mentioned crosslinking reaction can not be sufficiently progressed, and it becomes difficult to obtain a laminate having gas barrier properties. On the other hand, if it is too long, the productivity is lowered.

In addition, the coating solution for forming the gas barrier layer (II) applied to the plastic substrate (I) is subjected to high energy radiation such as ultraviolet light, X-ray, electron beam, etc. before and after the above drying, as necessary. It may be done. In such a case, a component that is crosslinked or polymerized by high energy radiation may be blended.

The laminate for heat sterilization of the present invention has an oxygen permeability of 10 ml / (m ² · day · MPa) measured in an atmosphere of 20 ° C. and a relative humidity of 65% after hot water treatment at 120 ° C. for 30 minutes. or ^{200ml / (m 2 · day ·} MPa) is required to be less, the oxygen permeability is preferably Among them 15～200Ml ^/ from the viewpoint of alcohol resistance (m 2 · day · MPa) , more preferably a ^{20~200ml / (m 2 · day ·} MPa), and most preferably ^{50~200ml / (m 2 · day ·} MPa).

Since the laminate for heat sterilization treatment of the present invention has the oxygen permeability as described above, when an alcohol-based content is filled as a packaging bag and heat sterilization treatment is performed, such as whitening or blistering phenomenon. The occurrence of appearance defects can be suppressed.
When the above oxygen permeability is less than 10 ml / (m ² · day · MPa), it does not have alcohol resistance, and when it is filled with an alcohol-based content and heat-sterilized, appearance defects occur Can not suppress. On the other hand, if the oxygen permeability exceeds 200 ml / (m ² · day · MPa), it can not be considered as having excellent gas barrier properties under high humidity.
The range of the oxygen permeability is the kind and content of the metal compound of the plastic substrate (I), the ratio of the metal compound to the polycarboxylic acid in the gas barrier layer (II), the thickness of the gas barrier layer (II), etc. Can be controlled by

  The laminate for heat sterilization treatment of the present invention preferably has a tensile strength of 150 MPa or more, and more preferably 180 MPa or more. If the tensile strength is less than 150 MPa, the mechanical strength is insufficient and the puncture strength tends to be reduced. Further, the tensile elongation is preferably 60% or more, more preferably 80% or more, from the same viewpoint as the tensile strength.

The pinhole resistance of the laminate for heat sterilization according to the present invention is such that the number of pinholes generated is preferably 100 or less, and 20 or less in a 500 repeated fatigue test under a 5 ° C. atmosphere. Is more preferred.
The above pinhole resistance is specifically described in Fed. Test Method Std. A 12 inch x 8 inch sample is held in a cylindrical shape of 3.5 inches in diameter according to Method 2017 of 101C, and an initial gripping distance of 7 inches and a gripping distance of 1 inch at maximum bending, a so-called gelbo tester (manufactured by Rigaku Kogyo Co., Ltd.) The number of pinholes generated after bending 500 times at 5 ° C. was measured and evaluated.

  The transparency of the laminate for heat sterilization treatment of the present invention is preferably 70% or less, more preferably 50% or less, still more preferably 30% or less, and 15% or less. Is particularly preferred, and most preferably 10% or less. However, depending on the application, this may not be necessary because transparency may not be required.

The laminate for heat sterilization treatment of the present invention can be produced by the following method.
The plastic base material (I) made of a film having a single layer structure is, for example, a thermoplastic resin mixed with a metal compound, heated and melted by an extruder and extruded from a T-die into a film, air knife casting, electrostatic application The film is cooled and solidified on a rotating cooling drum by a known casting method such as casting to obtain a film of an unstretched plastic substrate (I).
The plastic substrate (I) comprising a film having a multilayer structure is prepared, for example, by heating and melting a thermoplastic resin mixed with a metal compound with an extruder A, and heating and melting a thermoplastic resin with an extruder B. By laminating two melted resins in a die, for example, extruding a film of a two-layer structure of metal-containing layer (M) / resin layer (R) from a T-die, and cooling and solidifying as described above, It can be obtained in a stretched state.
By including the metal compound in the plastic base material (I) by such a method, the step of laminating the layer containing the metal compound, which has been conventionally performed, can be omitted.
The obtained single layer or multilayer unstretched film is coated with the coating solution for forming a gas barrier layer (II) by the method described above to form a gas barrier layer (II), and a tenter type simultaneous biaxial stretching machine By performing simultaneous biaxial stretching in the machine direction (MD) and the transverse direction (TD), a simultaneously biaxially stretched laminate can be obtained.
Moreover, after stretching the obtained unstretched film in the machine direction (MD), the coating solution for forming the gas barrier layer (II) is applied by the method described above to form the gas barrier layer (II), and then the transverse direction (TD Can be obtained to give a laminate that has been sequentially biaxially stretched.
In addition, since stretchability may fall in a post process when an unstretched film is orientated, it is preferable that an unstretched film is a substantially amorphous and non-oriented state.

When using a polyamide resin as a thermoplastic resin, transfer the unstretched film to a water bath adjusted so as not to exceed 80 ° C, subject it to water immersion treatment within 5 minutes, and carry out 0.5 to 15% moisture absorption treatment Is preferred.
Further, the stretching ratio of the film is preferably 1.5 times or more in the case of uniaxial stretching, and is preferably 1.5 times or more each in the longitudinal and transverse directions also in the case of longitudinal and transverse biaxial stretching. Usually, it is preferably 3 times or more, more preferably 6 to 20 times, and still more preferably 6.5 to 13 times. When the stretching ratio is in this range, it is possible to obtain a laminate of excellent mechanical properties.
The film subjected to the drawing treatment step is heat-set at a temperature of 150 to 300 ° C. in the tenter subjected to the drawing treatment, if necessary, in the range of 0 to 10%, preferably 2 to 6%, in the longitudinal direction and And / or a lateral relaxation treatment. In order to reduce the heat shrinkage rate, it is desirable not only to optimize the temperature and time of the heat setting time, but to perform the heat relaxation treatment at a temperature lower than the maximum temperature of the heat setting process.

  Although the stretching method is not particularly limited, it is preferable to use the simultaneous biaxial stretching method. The simultaneous biaxial stretching method can generally have practical properties such as mechanical properties, optical properties, thermal dimensional stability, and pinhole resistance. In addition, in the sequential biaxial stretching method in which longitudinal stretching is followed by transverse stretching, orientation crystallization of the film proceeds during longitudinal stretching and the stretchability of the thermoplastic resin during transverse stretching decreases, so that the compounding of the metal compound is performed. When the amount is large, the breakage frequency of the film tends to be high. For this reason, in the present invention, it is preferable to carry out a water absorption treatment and to adopt a simultaneous biaxial stretching method.

The laminate for heat sterilization treatment of the present invention can also be treated in a humidified atmosphere after producing the laminate for the purpose of enhancing the gas barrier properties. Humidification process, plastic substrate (I)
The action of the metal compound of the present invention and the polycarboxylic acid of the gas barrier layer (II) can be further promoted. In such humidification treatment, the laminate may be left in an atmosphere under high temperature and high humidity, or the laminate may be brought into direct contact with high temperature water. Humidification treatment conditions vary depending on the purpose, but when left under an atmosphere of high temperature and high humidity, a temperature of 30 to 130 ° C. and a relative humidity of 50 to 100% are preferable. Also when making it contact with high temperature water, about 30-130 degreeC (100 degreeC or more is under pressure) is preferable. Although the humidification treatment time varies depending on the treatment conditions, a range of several seconds to several hundred hours is generally selected.
The laminate for heat sterilization treatment of the present invention may be subjected to surface treatment such as corona discharge treatment, if necessary.

The laminate for heat sterilization treatment of the present invention can be made into various laminated films by laminating resin layers such as a printing ink layer, an adhesive layer, and a sealant.
As a resin used as a sealant, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polyethylene / polypropylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid / Methacrylic acid copolymer, ethylene-acrylic acid / methacrylic acid ester copolymer, polyvinyl acetate resin and the like, heat seal strength and strength of the material itself are high polyethylene, polypropylene, polyethylene / polypropylene copolymer, etc. Polyolefin resins are preferred. These resins may be used alone, or may be copolymerized or melt mixed with other resins, or may be further acid-modified.

As a method of forming a sealant layer in a laminate, a method of laminating a film or sheet made of a sealant resin on a laminate through an adhesive, a method of extruding a sealant resin on a laminate, and the like can be mentioned. . In the former method, the film or sheet made of the sealant resin may be in an unstretched state or in a stretched state at a low magnification, but practically it is preferably in the unstretched state.
The thickness of the sealant layer is not particularly limited, but is preferably 20 to 100 μm, and more preferably 40 to 70 μm.

Known materials are used as materials used to form a laminating adhesive. For example, isocyanate based, polyurethane based, polyester based, polyethylene imine based, polybutadiene based, polyolefin based, alkyl titanate based can be mentioned. Among these, in view of the effects of adhesion, heat resistance, water resistance and the like, isocyanate type, polyurethane type and polyester type are preferable. Furthermore, mixtures of one or more isocyanate compounds, polyurethane and urethane prepolymers and reaction products; mixtures of polyester compounds, polyols and polyethers with isocyanates and reaction products thereof preferable.
The thickness of the laminating adhesive is preferably greater than 0.1 μm, and preferably about 10 μm or less from the viewpoint of productivity.

The printing ink layer is a character, a pattern or the like formed of ink. As inks, various pigments, extender pigments, and additives such as plasticizers, desiccants, stabilizers and the like are added to ink binder resins such as urethane, acrylic, nitrocellulose, rubber, and vinyl chloride. Can be used.
As a formation method of a printing ink layer, well-known printing methods, such as an offset printing method, a gravure printing method, a screen printing method, can be used, for example.

A packaging bag can be produced using the laminate for heat sterilization treatment of the present invention, and the packaging bag is, for example, food and drink, fruit, juice, drinking water, liquor, cooked food, fish paste product, Various food and drink products such as frozen food, meat products, simmered food, rice bran, liquid spruce, seasoning and others, and contents such as liquid detergents, cosmetics and chemical products can be filled and packaged.
In particular, it is suitable as a packaging bag for filling contents containing alcohol. As the alcohol, ethanol, isobutanol, n-propanol and the like can be mentioned.

  EXAMPLES The present invention will next be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

1. Measurement Method (1) Thickness of Each Layer The obtained laminate is allowed to stand under an environment of 23 ° C. and 50% RH for 2 hours or more, and then the cross section of the film is observed by a scanning electron microscope (SEM) to measure the thickness of each layer. did.
(2) Oxygen Permeability After subjecting the obtained laminate to hot water treatment at 120 ° C. for 30 minutes, it is left in an environment of 20 ° C., 65% RH for 2 hours or more, and then oxygen barrier measurement made by Mocon Corporation The oxygen permeability in an atmosphere with a temperature of 20 ° C. and a relative humidity of 65% was measured using a container (OX-TRAN 2/20). The unit is ml / (m ² · day · MPa).

(3) Appearance evaluation of the package After filling and sealing the contents 150 g of the following constitution in a three-way bag (outer size: 200 mm in length × 150 mm in width, 10 mm in seal width) manufactured with the obtained packaging bag Retort treatment (hot water shower type, 120 ° C., 30 minutes, 1.8 kg / cm ² ) was performed, and the appearance of the treated package was evaluated. The appearance was judged visually, and a case where there was no appearance defect was marked with 〇, a case where whitening or blister-like projections were generated and there was a defect in appearance was marked as x.
As the contents to be charged, an aqueous ethanol solution having an ethanol concentration of 0.5%, 1.0%, 1.5%, and 2.0% (all based on mass) was used.

2. Raw Materials Raw materials used in the following Examples and Comparative Examples are as follows.
(1) Thermoplastic resin for construction of plastic base material (I), PA6: nylon 6 resin (Unitika A1030 BRF, relative viscosity 3.0)
-PET: polyethylene terephthalate resin (UNITCA UT-CBR limiting viscosity 0.62)

(2) Metal compound for forming plastic base material (I), magnesium oxide (Tateho Chemical Industries, Ltd. PUREMAG FNM-G, average particle size 0.4 μm)
・ Magnesium carbonate (Kanjima Chemical Industry Co., Ltd. MSS average particle diameter 1.2 μm)
Calcium carbonate (Shiroishi Kogyo Vigot 15 average particle size 0.5 μm)
・ Zinc oxide (FINEX-50 manufactured by Sakai Chemical Industry Co., Ltd. Average particle size 0.02 μm)

(3) Metal compound master chip / master chip 1 for plastic base material (I) constitution
A master chip was prepared by kneading 95 parts by mass of PA6 and 5 parts by mass of magnesium oxide to prepare a metal-containing layer (M) having a content of the metal compound of less than 5% by mass.
・ Master chip 2
55 parts by mass of PA6 and 45 parts by mass of magnesium oxide were kneaded to prepare a master chip, and used when preparing a metal-containing layer (M) having a content of metal compound of 5 to 15% by mass .
・ Master chip 3
It was prepared by kneading 95 parts of PA6 and 5 parts by mass of magnesium carbonate.
・ Master chip 4
It was prepared by kneading 95 parts of PA6 and 5 parts by mass of calcium carbonate to prepare a metal-containing layer (M) in which the content of the metal compound is less than 5% by mass.
・ Master chip 5
70 parts of PA6 and 30 parts by mass of calcium carbonate were kneaded to prepare, and used when preparing the metal-containing layer (M) having a content of the metal compound of 5 to 15% by mass.
・ Master chip 6
It was prepared by kneading 85 parts of PA6 and 15 parts by mass of zinc oxide.
Master chip 7
It was prepared by kneading 95 parts by mass of PET and 5 parts by mass of magnesium oxide.

(4) Polycarboxylic acid component of coating liquid for forming gas barrier layer (II) · EMA aqueous solution:
EMA (weight average molecular weight 60,000) and sodium hydroxide are added to water, dissolved by heating and cooled to room temperature, 10 mol% of carboxyl groups of EMA are neutralized by sodium hydroxide, solid 15 mass% EMA aqueous solution.
・ PAA aqueous solution:
10 mol% of carboxyl groups of polyacrylic acid prepared by using polyacrylic acid (A10H manufactured by Toagosei Co., Ltd., number average molecular weight 200,000, 25% by weight aqueous solution) and sodium hydroxide 15% solids by weight polyacrylic acid (PAA) aqueous solution mixed.

(5) Other resin components of the coating liquid for forming the gas barrier layer (II) · PVA aqueous solution:
Polyvinyl alcohol (solid content 15% by mass) prepared by adding polyvinyl alcohol (Kovara poval 105, degree of saponification 98 to 99%, average degree of polymerization about 500) to water, heating and dissolving, and cooling to room temperature PVA) aqueous solution.
・ EVOH aqueous solution:
An ethylene-vinyl alcohol copolymer (EVOH) aqueous solution having a solid content of 10% by mass, in which an ethylene-vinyl alcohol copolymer (Exeval AQ-4105 manufactured by Kuraray Co., Ltd.) is dissolved.
・ PAM:
Polyacrylamide (manufactured by Kishida Chemical Co., Ltd., reagent, weight average molecular weight 9,000,000 to 10,000,000, degree of polymerization: 127,000 to 141,000).

Sealant film:
CPP: Mitsui Chemicals Tosoh Co. RXC-22, 50 μm thick polypropylene film adhesive:
Polyurethane-based adhesive: Dick Dry LX-500 / KR-90S manufactured by DIC Graphics.

Example 1
The nylon 6 resin and the master chip were mixed such that the content of magnesium oxide was 0.1% by mass. The mixture was charged into the extruder and melted in a 270 ° C. cylinder. The melt was extruded into a sheet form from a T-die orifice, brought into close contact with a rotating drum cooled to 10 ° C., and quenched to obtain an unstretched plastic substrate (I) film with a thickness of 150 μm.
The obtained unstretched film was sent to a 50 ° C. water bath and subjected to a water immersion treatment for 2 minutes.
Next, a coating solution for forming a gas barrier layer (II) having a solid content of 10% by mass is mixed with an aqueous solution of EMA and an aqueous solution of EMA so that the mass ratio (solid content) of PVA and EMA is 50/50. I got The coating liquid was applied to one surface of the water-immersed unstretched film and then dried.
The end of the film was held by the clips of a tenter-type simultaneous biaxial stretching machine, and stretched at MD at 180 ° C. and 3.3 times each in TD. After that, the relaxation rate of TD is 5%, 210 ° C
Heat-treated for 4 seconds, gradually cooled to room temperature, and 15 μm thick plastic substrate (I)
A laminated body in which a gas barrier layer (II) having a thickness of 0.3 μm was laminated was obtained.

Examples 2 to 3, 7 to 14, 16 Comparative Examples 1 to 4 , Reference Examples 4 to 6
Example 1 was repeated except that the nylon 6 resin and the master chip were mixed so that the metal compound content described in Table 1 was obtained, and the thickness after stretching was made to be the thickness described in Table 1 Similarly, unstretched plastic substrate (I) film was obtained and subjected to water immersion treatment.
Next, a gas barrier layer (II) was prepared in the same manner as in Example 1 except that the type and mass ratio (solid content) of other resins such as PVA and the like were as described in Table 1. ) A coating solution for formation was prepared.
In the same manner as in Example 1, except that the thickness after stretching was made to be the thickness described in Table 1 using the obtained coating liquid, the film was applied to an unstretched film, dried, and simultaneously biaxially stretched. The laminate was obtained.
In Example 16, the conditions were changed as follows in connection with having used polyethylene terephthalate resin (PET) as a thermoplastic resin. That is, an unstretched film was produced at a cylinder temperature of 280 ° C., and the obtained unstretched film was not subjected to water immersion treatment. Moreover, the temperature in simultaneous biaxial stretching was 90 ° C., and the temperature of heat treatment was 230 ° C.

Example 15
The coating liquid for gas barrier layer (II) formation was prepared as follows.
That is, polyacrylic acid (PAA) having a number average molecular weight of 200,000 was dissolved in distilled water to obtain a PAA aqueous solution having a solid content concentration of 13% by mass in the aqueous solution. Subsequently, a 13% by mass aqueous ammonia solution was added to the aqueous PAA solution to neutralize 1 mol% of the carboxyl group of PAA to obtain an aqueous solution of partially neutralized PAA.
In addition, 100 parts by mass of polyacrylic acid (PAA) having a number average molecular weight of 40,000 was dissolved in 1064 parts by mass of methanol, and then 166 parts by mass of γ-aminopropyltrimethoxysilane (APTMOS) was added while stirring. Thus, an APTMOS methanol solution (15-1) was obtained. In the APTMOS methanol solution (15-1), at least a part of the amino groups of APTMOS is neutralized by the carboxyl group of PAA.
Next, a TMOS methanol solution was prepared by dissolving 34.5 parts by mass of tetramethoxysilane (TMOS) in 34.5 parts by mass of methanol. While maintaining the temperature of the TMOS methanol solution at 10 ° C. or less, 2.3 parts by mass of distilled water and 5.7 parts by mass of 0.1 M hydrochloric acid are added, and hydrolysis and condensation are carried out at 10 ° C. for 60 minutes while stirring. The reaction was carried out to obtain a solution (15-2).
Subsequently, the solution (15-2) is diluted with 214.7 parts by mass of methanol and 436.1 parts by mass of distilled water, and then 235.9 parts by mass of the partially neutralized aqueous solution of PAA is added while stirring. The solution (15-3) was obtained.
Subsequently, 36.2 parts by mass of APTMOS methanol solution (15-1) was added while stirring the solution (15-3), and the solution (15-4) was obtained by further stirring for 30 minutes.
A laminate was obtained in the same manner as Example 1, except that the solution (15-4) prepared by the above method was used as a coating solution for forming a gas barrier layer (II).

Example 17
Nylon 6 resin and a master chip were mixed so that content of magnesium oxide might be 0.8 mass%. This mixture was charged into extruder A and melt extruded at 260 ° C. On the other hand, nylon 6 resin was charged into the extruder B and melt extruded at 260 ° C.
Two kinds of resins respectively melted by the extruder A and the extruder B are stacked in a die, and a sheet of a two-layer structure of metal-containing layer (M) / resin layer (R) is extruded from a T die, and the surface temperature 20 The film was brought into close contact with a cooling roller of 150 ° C. to obtain a 150 μm-thick unstretched multilayer film with (M) / (R) = 20/130 μm. The obtained unstretched multilayer film is sent to a 50 ° C. hot water tank, 2
A submersion treatment was performed for one minute.
Next, an unstretched multilayer film was prepared in the same manner as in Example 1 except that the mass ratio (solid content) of PVA and polycarboxylic acid was as shown in Table 1. The solution was applied to the surface of the metal-containing layer (M) and dried.
A plastic substrate having a thickness of 15 μm comprising a metal-containing layer (M) having a thickness of 2 μm and a resin layer (R) having a thickness of 13 μm subjected to simultaneous biaxial stretching and heat treatment in the same manner as in Example 1 A laminate was obtained in which a gas barrier layer (II) having a thickness of 0.3 μm was laminated on the metal-containing layer (M) of I).

An adhesive (LX-500 / KR-90S: 13/1 in mass ratio) manufactured by DIC Graphics Co. is manufactured on the gas barrier layer of the laminates for heat sterilization of Examples 1 to 17 and Comparative Examples 1 to 4 obtained. It apply | coated by the dry laminator, and formed the 2.5-micrometer-thick adhesive layer.
After bonding a sealant film (CPP, RXC-22, thickness 50 μm) manufactured by Mitsui Chemicals Toshiro Co., Ltd. as a heat seal layer to the adhesive layer, it is allowed to stand at 40 ° C. for 2 days to cure the adhesive layer, It was used to obtain a packaging bag.

  Table 1 shows the structures of the laminates obtained in Examples and Comparative Examples, and the results of evaluating the oxygen permeability and the appearance of the package after retort treatment.

In each of Examples 1 to 3 and 7 to 17, a laminate excellent in gas barrier properties and alcohol-based content suitability was obtained.
On the other hand, in Comparative Example 1, the metal compound contained in the plastic base material (I) was less than 0.1% by mass, so a laminate having sufficient gas barrier properties could not be obtained.
In Comparative Examples 2 and 3, since the oxygen permeability was less than 20 ml / (m ² · d · MPa), appearance defects occurred after retort treatment in which the alcohol-based content was filled.
In Comparative Example 4, since the gas barrier layer (II) did not contain a polycarboxylic acid, a laminate having sufficient gas barrier properties could not be obtained.

Claims (6)

A laminate in which a gas barrier layer (II) is laminated on a plastic substrate (I), wherein the plastic substrate (I) contains 0.1 to 10% by mass of a metal compound, and the gas barrier layer (II) is poly After containing a carboxylic acid and treated with hot water at 120 ° C for 30 minutes, the oxygen permeability in an atmosphere at 20 ° C and a relative humidity of 65% is at least 20 ml / (m ² · day · MPa) 200 ml / (m ² · day · MPa) alcohol-containing product packaging bag characterized in that it contains an der Ru heat sterilization laminate for less. The packaging bag for alcohol-containing materials according to claim 1, wherein the plastic substrate (I) is a multilayer film, and at least one layer thereof contains 0.1 to 10% by mass of a metal compound. The packaging bag for an alcohol-containing material according to claim 1 or 2, wherein the thermoplastic resin constituting the plastic base material (I) is a polyamide resin or a polyester resin. The packaging bag for alcohol-containing material according to any one of claims 1 to 3, wherein the gas barrier layer (II) contains a polyalcohol . The packaging bag for alcohol-containing material according to any one of claims 1 to 4, wherein the metal constituting the metal compound is one selected from magnesium, calcium and zinc. The packaging bag for alcohol-containing material according to any one of claims 1 to 5, which is simultaneously or sequentially biaxially stretched.