JP7085107B2 - Laminated body and packaging material composed of the laminated body - Google Patents

Description

The present invention relates to a laminate and a packaging material composed of the laminate.

In many product fields such as foods, beverages, pharmaceuticals, and chemicals, packaging materials and packages according to their contents have been developed.

For example, each sliced cheese is filled in a packaging material made of a resin film or the like, and each of the plurality of sliced cheeses is enclosed in a packaging bag, but the quality of the sliced cheese is usually deteriorated due to drying. In order to prevent this, a packaging bag having high water vapor barrier property and oxygen barrier property is used.

However, the conventional packaging material enclosed in the packaging bag does not have sufficient water vapor barrier property and oxygen barrier property. Therefore, once the packaging bag is opened, the sliced cheese is dried and its quality is deteriorated. There was a problem of doing

Now, the present inventors have described the above problem by using a laminate including a heat seal layer, a base material, a thin film, a gas barrier layer, a delamination layer, and a seal layer as a packaging material. It was found that the problem can be solved.

Therefore, the problem to be solved this time is to provide a laminated body capable of producing a packaging bag having high water vapor barrier property and oxygen barrier property.

The laminate of the present invention is characterized by including a heat seal layer, a base material, a thin film, a gas barrier layer, a delamination layer, and a seal layer.

In one embodiment, the laminate of the present invention further comprises a water repellent layer so as to be surface-sequential to the heat seal layer.

In one embodiment, the laminate of the present invention further comprises an anchor layer between the water repellent layer and the heat seal layer.

In one embodiment, the gas barrier layer included in the laminate of the present invention is a layer formed by a coating liquid for forming a gas barrier layer containing a gas barrier resin and an alkoxide represented by the general formula ^R1 _nm (OR ² ) _m . Is.

In one embodiment, the coating liquid for forming a gas barrier layer contains polyvinyl alcohol and / or an ethylene / vinyl alcohol copolymer.

In one embodiment, the vapor-deposited film included in the laminate of the present invention comprises silicon oxide or aluminum oxide.

In one embodiment, the delamination layer included in the laminate of the present invention contains polypropylene.

In one embodiment, the thickness of the delamination layer included in the laminate of the present invention is 1 μm or more and 100 μm or less.

In one embodiment, the water-repellent layer included in the laminate of the present invention contains a polyamide-based resin and a cellulosic-based resin.

The packaging material for sliced cheese of the present invention is characterized by comprising the above-mentioned laminate.

According to the laminate of the present invention, a packaging bag having high water vapor barrier property and oxygen barrier property can be produced.

FIG. 1 is a schematic cross-sectional view of the laminated body of the present invention. 2A is a sectional view taken along line XX of FIG. 2B, and FIG. 2B is a front view of the packaging material of the present invention.

(Laminated body)
As shown in FIG. 1, the laminate 10 of the present invention includes a heat seal layer 11, a base material 12, a vapor deposition film 13, a gas barrier layer 14, a delamination layer 15, and a seal layer 16.
Further, in one embodiment, as shown in FIG. 1, the laminated body 10 of the present invention includes a water-repellent layer 17 so as to be surface-sequential to the heat-sealed layer 11.
Further, in one embodiment, the laminate 10 of the present invention further includes an anchor layer 18 between the base material 12, the water repellent layer 17, and the heat seal layer 11, as shown in FIG.
Hereinafter, each layer constituting the laminated body of the present invention will be described in detail.

(Heat seal layer)
The laminate of the present invention includes a heat seal layer, and the heat seal layer forms the following primary seal portion together with the seal layer. Further, when the primary seal portion is peeled off, the heat seal layer causes coagulation fracture.

The heat seal layer can contain a thermoplastic resin that is softened by heating and exhibits adhesion.
Examples of the thermoplastic resin include polyester resin, vinyl resin, (meth) acrylic resin, (meth) acrylic resin, polyurethane resin, cellulose resin, melamine resin, polyamide resin, polyolefin resin and the like. Examples include styrene resin.
Among the above-mentioned thermoplastic resins, vinyl-based resins are preferable, and ethylene-vinyl acetate copolymers are particularly preferable, from the viewpoint of heat-sealing properties and blocking resistance.

The above-mentioned thermoplastic resin may be modified with an unsaturated carboxylic acid or a derivative thereof, and examples of the unsaturated carboxylic acid include maleic acid, itaconic acid, fumaric acid and (meth) acrylic acid. Examples of the derivative of the saturated carboxylic acid include maleic anhydride, maleic acid monoester, maleic acid diester, itaconic acid monoester, itaconic acid diester, itaconic anhydride, fumaric acid monoester and fumaric acid diester.
From the viewpoint of heat resistance of the heat seal layer, an ethylene-vinyl acetate copolymer modified with maleic anhydride is preferable.

Further, from the viewpoint of blocking resistance of the laminated body, it is preferable that the heat seal layer contains a polyamide resin. Examples of the polyamide resin include ring-opening polymers and copolymers such as ε-aminocaprolactam and ω-aminolaurolactum, polymers of ε-aminoundecanoic acid, amines such as hexamethylenediamine, and adipic acid and sepadic acid. Examples thereof include a polymer with an acid such as. More specifically, nylon-6, nylons 6, 6 and the like can be mentioned.

The content of the thermoplastic resin in the heat seal layer is preferably 50% by mass or more and 100% by mass, and more preferably 50% by mass or more and 99% by mass or less. By setting the content of the thermoplastic resin within the above numerical range, it is possible to prevent the heat-sealing property from being exhibited at a low temperature (for example, 50 ° C.) while maintaining the heat-sealing property.

The heat seal layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. good.

The thickness of the heat seal layer is preferably 0.3 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

The heat seal layer is a known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method by dispersing or dissolving the above-mentioned material in water or an appropriate solvent. It can be formed by applying it on a base material or an anchor layer to form a coating film and drying it. A heat-sealing layer can also be formed by applying a commercially available heat-sealing agent on a base material or an anchor layer and drying it.

(Base material)
As the base material, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylene methylene terephthalate, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, etc. Polyester resin, polyamide resin, polyethylene (PE), polypropylene (PP), polyolefin resin such as polymethylpentene, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer , Vinyl-based resins such as polyvinyl butyral and polyvinylpyrrolidone (PVP), (meth) acrylic resins such as polyacrylate, polymethacrylate and polymethylmethacrylate, polyimide-based resins such as polyimide and polyetherimide, cellophane, cellulose acetate. , Nitrocellulose, cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB) and other cellulose resins, polystyrene (PS) and other polystyrene resins, polycarbonate resins, ionomer resins and the like. (Hereinafter, simply referred to as "resin film") can be used.
Among the above, a polyester resin, particularly a film made of PET, is preferable from the viewpoint of dimensional stability, water resistance, and mechanical strength.

Further, the above-mentioned laminated body of the resin film can also be used as a base material. The laminate of the resin film can be produced by using a dry lamination method, a wet lamination method, an extraction method, or the like.

The resin film may be a stretched film or an unstretched film, but from the viewpoint of strength, it is preferable to use a stretched film stretched in the uniaxial direction or the biaxial direction.

The thickness of the base material is not particularly limited, but can be, for example, 1 μm or more and 100 μm or less.

(Embedded film)
The laminate of the present invention includes a vapor-deposited film on a substrate. Thereby, the water vapor barrier property and the oxygen barrier property of the laminated body of the present invention can be improved.

The vapor deposition film is, for example, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti). , Lead (Pb), zirconium (Zr), yttrium (Y) and other inorganic substances or inorganic oxides can be contained. Among these, silicon oxide or aluminum oxide is preferable because of production stability, elution property, and safety.

The above-mentioned inorganic oxide can be represented by the general formula MO _X. (In the formula, M represents an inorganic element, and the value of X has a different range depending on the inorganic element.).
The range of the value of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), and calcium (Ca). 0 to 1, potassium (K) 0 to 0.5, tin (Sn) 0 to 2, sodium (Na) 0 to 0.5, boron (B) 0 to 1.5, 0 to 2 for titanium (Ti), 0 to 1 for lead (Pb), 0 to 2 for zirconium (Zr), 0 to 1.5 for yttrium (Y). be.
When X = 0, it is a completely inorganic simple substance (pure substance), and the upper limit of the range of X is a completely oxidized value.

Among the above, the thin-film film preferably contains silicon oxide represented by the general formula: SiO _x (where x represents a number of 0 to 2, preferably 1.3 to 1.9). ..
Further, the vapor-filmed film containing silicon oxide may contain a compound containing one or more of carbon, hydrogen, silicon or oxygen by a chemical bond or the like.
Examples of such a compound include a hydrocarbon having a CH ₃ moiety, a hydrosilica such as SiH ₃ silyl and SiH ₂ silylene, and a hydroxyl derivative such as SiH ₂ OH silanol.
The content of the compound in the thin-film film is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.
Further, it is preferable that the content concentration of the compound decreases as it approaches the substrate. By having such a structure in the thin-film deposition film, it is possible to improve the impact resistance of the thin-film deposition film while maintaining the adhesion between the base material and the thin-film deposition film.

The thickness of the thin-film film is preferably changed as appropriate depending on the type of the inorganic substance or the inorganic oxide used, but can be, for example, 10 Å or more and 2000 Å or less.
When the vapor-deposited film contains a silicon oxide or an aluminum oxide, its thickness is preferably 10 Å or more and 500 Å or less, and more preferably 10 Å or more and 300 Å or less.

The method for forming the vapor deposition film is not particularly limited, and is a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method and an ion plating method, or a plasma chemical vapor deposition method, a thermochemical vapor deposition method, and a photochemical vapor deposition method. Chemical vapor deposition method such as method can be mentioned.

(Gas barrier layer)
The laminate of the present invention includes a gas barrier layer formed by a coating liquid for forming a gas barrier layer containing a gas barrier resin. Thereby, the water vapor barrier property and the oxygen barrier property of the laminated body of the present invention can be improved. Further, the laminate of the present invention may include two or more gas barrier layers.

Examples of the gas barrier resin include polymethoxylylene adipamide (MXD-6), polyglycolic acid (PGA), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH) and polyethylene naphthalate (PEN). And so on. The gas barrier layer can contain two or more of the above-mentioned gas barrier resins.

The content of the gas barrier resin in the coating liquid for forming the gas barrier layer is more preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less. By setting the content of the gas barrier resin within the above numerical range, the water vapor barrier property and the oxygen barrier property of the gas barrier layer can be further improved.

The coating liquid for forming the gas barrier layer may contain an alkoxide represented by the general formula: ^R1 _nm (OR ² ) _m .
The gas barrier layer formed by the coating liquid contains a partial hydrolyzate of alkoxide and / or a hydrolyzed condensate of alkoxide.
As the partial hydrolyzate of the alkoxide, it is not necessary that all of the alkoxy groups are hydrolyzed, and one or more of them may be hydrolyzed, or a mixture thereof. Further, the hydrolyzed condensate represents a dimer or more of a partially hydrolyzed alkoxide, and a dimer to a hexamer is usually used.
Further, the gas barrier layer can contain two or more kinds of a partial hydrolyzate of alkoxide and a hydrolyzed condensate of alkoxide.

In the above formula, M represents a metal atom, and examples thereof include silicon, zirconium, titanium, and aluminum. Among these, M is preferably aluminum or silicon because of its water vapor barrier property and oxygen barrier property.

In the above formula, R ¹ and R ² each represent an alkyl group having 1 to 8 carbon atoms, and for example, a methyl group, an ethyl group, an n-propyl group n-propyl group, an i-propyl group, an n-butyl group, and the like. Examples thereof include i-butyl group, sec-butyl group, t-butyl group, n-hexyl group and n-octyl group. In addition, R ¹ and R ² may be the same or different.

In the above formula, n represents 0 or an integer of 1 or more, and is preferably 0. Further, m represents an integer of 1 or more, and is preferably an integer of 1 or more and 5 or less.

Among the alkoxides represented by the above general formula, the alkoxysilane represented by the general formula Si (OR ^a ) ₄ is preferable.
In the above formula, Ra represents an alkyl group having 1 or more and 5 or less carbon atoms, and examples thereof include ^a methyl group, an ethyl group, an N-propyl group and an N-butyl group.
More specifically, tetramethoxysilane Si (OCH ₃ ) ₄ , tetraethoxysilane Si (OC ₂ H ₅ ) ₄ , tetrapropoxysilane Si (OC ₃ H ₇ ) ₄ , and tetrabutoxysilane Si (OC ₄ H ₉ ). ₄ etc. can be mentioned.

The coating liquid for forming the gas barrier layer contains polyvinyl alcohol and / or an ethylene / vinyl alcohol copolymer. By forming the gas barrier layer with the coating liquid, the water vapor barrier property, oxygen barrier property, water resistance and weather resistance of the gas barrier layer can be remarkably improved.
Furthermore, when the coating liquid for forming the gas barrier layer contains polyvinyl alcohol and an ethylene / vinyl alcohol copolymer, in addition to improving the water vapor barrier property, oxygen barrier property, water resistance and weather resistance, heat and water resistance and after hot water treatment It is possible to improve the water vapor barrier property and the oxygen barrier property.

The content of polyvinyl alcohol and / or ethylene / vinyl alcohol copolymer in the coating liquid for forming a gas barrier layer is preferably 5 parts by mass or more and 600 parts by mass or less, preferably 50 parts by mass or more, with respect to 100 parts by mass of alkoxide. , 400 parts by mass or less is preferable. By setting the content within the above numerical range, the water resistance and weather resistance of the gas barrier layer can be further improved.

The coating liquid for forming the gas barrier layer may contain a silane coupling agent. By including the silane coupling agent in the gas barrier layer, the adhesion with the vapor deposition layer is improved. As the silane coupling agent, for example, organoalkoxysilane having an organic reactive group can be used.
In particular, organoalkoxysilanes having an epoxy group as organic reactive groups are preferable, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxy). Cyclohexyl) ethyltrimethoxysilane and the like can be mentioned.

The content of the silane coupling agent in the coating liquid for forming the gas barrier layer is preferably 0.001 part by mass or more and 10 parts by mass or less, and 0.005 part by mass or more and 5 by mass with respect to 100 parts by mass of the alkoxide. It is preferably less than or equal to parts by mass. By setting the content within the above numerical range, the adhesion with the gas barrier layer can be further improved.

The coating liquid for forming the gas barrier layer may contain a sol-gel process catalyst. In one embodiment, a tertiary amine that is substantially insoluble in water and soluble in an organic solvent is used as the sol-gel process catalyst. Examples of such tertiary amines include N, N-dimethylbenzylamine, tripropylamine, tributylamine, and trypentylamine.

The content of the sol-gel method catalyst in the coating liquid for forming the gas barrier layer shall be 0.01 part by mass or more and 1.0 part by mass or less with respect to 100 parts by mass of the total content of the alkoxysilane and the silane coupling agent. preferable.

The gas barrier layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. ..

The coating liquid for forming the gas barrier layer can contain acids such as sulfuric acid, hydrochloric acid, nitric acid, acetic acid and tartaric acid.
The acid content in the coating liquid for forming the gas barrier layer is 0.001 mol or more and 0.05 mol or less with respect to the total molar amount of the alkoxide portion (for example, the silicate portion) of the alkoxide and the silane coupling agent. It is preferably 0.01 mol or more and 0.03 mol or less.

The coating liquid for forming the gas barrier layer may contain water. The water content in the coating liquid for forming the gas barrier layer is preferably 0.1 mol or more and 100 mol or less, preferably 0.8 mol or more and 2 mol or less, with respect to 1 mol of the total molar amount of alkoxide. It is more preferable to have. By setting the water content within the above numerical range, the water vapor barrier property and the oxygen barrier property of the gas barrier layer can be further improved.

The coating liquid for forming the gas barrier layer may contain an organic solvent. Examples of the organic solvent include methyl alcohol, acetone, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol and the like.

The thickness of the gas barrier layer is preferably 0.01 μm or more and 100 μm or less, and more preferably 0.01 μm or more and 50 μm or less. By setting the thickness of the gas barrier layer within the above numerical range, the water vapor barrier property and the oxygen barrier property of the laminated body can be further improved.

The gas barrier layer is formed by applying a coating liquid for forming a gas barrier layer onto a substrate or the like by a known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method. It can be formed by applying it to a coating film to form a coating film and drying it.
In the step of drying the coating film, polycondensation of the alkoxide, the silane coupling agent, the vinyl alcohol polymer and the like proceeds, and a layer of the composite polymer is formed.
The heating in the drying step is performed at a temperature of 100 ° C. or higher and 250 ° C. or lower for 20 seconds or longer and 10 minutes or shorter.

(Delamination layer)
The laminate of the present invention includes a delamination layer. Since the laminate of the present invention is provided with the delamination layer, the secondary seal strength can be improved. When the secondary seal portion is peeled off, it is peeled off between the delamination layer and the seal layer.
In one embodiment, the delamination layer comprises polypropylene. Examples of polypropylene include block PP, random PP, homo-PP and PP modified with unsaturated carboxylic acid or a derivative thereof. Among these, random PP is preferable from the viewpoint of processability. The delamination layer may contain two or more types of polypropylene.
The unsaturated carboxylic acid or its derivative is as described above. Among these, PP modified with maleic anhydride is preferable from the viewpoint of adhesion to an adjacent layer.

The content of polypropylene in the delamination layer is preferably 50% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less. Thereby, the strength of the secondary sealing portion (the sealing strength between the delamination layer and the sealing layer) can be made better.

To the extent that the characteristics of the present invention are not impaired, the delamination layer is a resin such as a polyolefin resin other than polypropylene, a polyester resin, a (meth) acrylic resin, a polyamide resin, a vinyl resin, a cellulose resin, and a styrene resin. Materials can be included.

The delamination layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. good.

The thickness of the delamination layer is preferably 2 μm above and 20 μm or less, and more preferably 3 μm or more and 15 μm or less. By setting the thickness of the delamination layer within the above numerical range, the adhesion to the anchor layer can be improved and the strength of the secondary seal portion can be improved.

The delamination layer is a known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method by dispersing or dissolving the above-mentioned material in water or an appropriate solvent. It can be formed by applying it on a gas barrier layer or the like to form a coating film and drying it.

(Seal layer)
The laminate of the present invention comprises a seal layer, which together with the heat seal layer forms the following primary seal portion. Further, the following secondary seal portions are formed by the seal layers, and at the time of peeling, the seal layers are peeled between the delamination layer and the delamination layer.

The seal layer can contain the above-mentioned thermoplastic resin. Among the above-mentioned thermoplastic resins, polyolefin-based resins are preferable, and polyethylene is more preferable, because the strength of the primary and secondary sealing portions can be improved. Polyethylene includes high-density polyethylene, medium-density polyethylene, low-density polyethylene and linear low-density polyethylene, and among these, low-density polyethylene and linear low-density polyethylene are preferable.
In general, high-density polyethylene has a density of 0.940 g / cm ³ or more, medium-density polyethylene has a density of 0.925 to 0.940 g / cm ³ , and low-density polyethylene has a density of 0. .It means less than 925 g / cm ³ .

The content of the thermoplastic resin in the seal layer is preferably 50% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less. By setting the content of the thermoplastic resin within the above numerical range, the strength of the primary and secondary seal portions can be improved.

The seal layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. ..

The thickness of the seal layer is preferably 1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. By setting the thickness of the seal layer within the above numerical range, the strength of the primary and secondary seal portions can be made good.

The seal layer is formed by dispersing or dissolving the above material in water or an appropriate solvent and using known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method. It can be formed by applying it on a substrate or the like to form a coating film and drying it. The seal layer can also be formed by melt-extruding the thermoplastic resin onto the delamination layer.

(Water repellent layer)
In one embodiment, the laminate of the present invention comprises a water repellent layer. The laminate of the present invention is subjected to water cooling treatment and drainage treatment after filling with cheese, and the drainage treatment can be easily performed by providing the laminate of the present invention with a water repellent layer.

The water-repellent layer may contain a resin material such as a polyamide resin, a cellulosic resin, a (meth) acrylic resin, a vinyl resin, a polyurethane resin, and a polyolefin resin. Among these, a polyamide resin and a cellulosic resin are preferable from the viewpoint of water repellency, and it is more preferable to use them in combination.
Particularly preferably, the water-repellent layer contains 60% by mass or more and 80% by mass or less of the polyamide resin and 20% by mass or more and 40% by mass or less of the cellulosic resin. Thereby, the water repellency and heat resistance of the water repellent layer can be improved.

Further, the water-repellent layer can include particles such as fluororesin particles made of silicone particles, polytetrafluoroethylene and the like, silica particles, alumina particles and nylon particles. When the water-repellent layer contains these particles, the water repellency of the water-repellent layer can be improved.
In the water-repellent layer, the content of these particles is preferably 2 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin material. By setting the content of the particles within the above numerical range, the water repellency can be improved while maintaining the moldability of the water repellent layer.

The water-repellent layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. good.

The thickness of the water-repellent layer is preferably 0.1 μm or more and 3 μm or less, and more preferably 0.1 μm or more and 1 μm or less. Sufficient water repellency is exhibited by setting the thickness of the water repellent layer within the above numerical range.

The water-repellent layer is a known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method by dispersing or dissolving the above-mentioned material in water or an appropriate solvent. It can be formed by applying it on a substrate or the like to form a coating film and drying it.

(Anchor layer)
In one embodiment, the laminate of the present invention comprises an anchor layer between any layers, eg, a gas barrier layer and a delamination layer. When the laminated body includes the anchor layer, the adhesion between the two adjacent layers can be improved.

The anchor layer may contain a resin material such as a polyolefin-based resin, a polyurethane-based resin, a vinyl-based resin, or a (meth) acrylic-based resin. Further, the anchor layer may contain a copolymer obtained by polymerizing the monomers constituting the resin.
Among the above, a polyolefin resin is preferable, polypropylene such as block PP, random PP and homo PP is more preferable, and random PP and homo PP are further preferable, from the viewpoint of adhesion to the delamination layer.
The anchor layer can contain two or more of the above-mentioned resin materials.

Further, the anchor layer preferably contains a polyurethane resin. When the anchor layer contains a polyurethane resin, the adhesion to the base material can be improved.
The polyurethane resin can be obtained by reacting a polyol compound with a polyisocyanate compound.
Examples of the polyol compound include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and 1,6-hexanediol. , Neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, Examples thereof include trimethylolpropane, glycerin, pentaerythritol, bisphenol A and bisphenol F.
Examples of the isocyanate compound include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylenediocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalenedi isocyanate, isophorone diisocyanate, dimethyldiisocyanate, and lysine diisocyanate. Examples thereof include hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimerged isocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group, and adducts, biurets, and isocyanurates thereof.

The anchor layer may contain a cross-linking agent such as an oxazoline group-containing compound, a carbodiimide group-containing compound, an isocyanate group-containing compound, an epoxy group-containing compound, a melamine compound, a urea compound, a zirconium salt compound and a silane coupling agent.
Among the above-mentioned cross-linking agents, oxazoline group-containing compounds, carbodiimide group-containing compounds, isocyanate group-containing compounds and epoxy group-containing compounds are preferable from the viewpoint of ease of handling.

The anchor layer may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic fine particles, organic fine particles, mold release agents, and dispersants as long as the characteristics of the present invention are not impaired. ..

The thickness of the anchor layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less.

The anchor layer is formed by dispersing or dissolving the above material in water or an appropriate solvent and using known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method. It can be formed by applying it on a substrate or the like to form a coating film and drying it. An anchor layer can also be formed by applying a commercially available anchor coating agent and drying it.

(Packaging material)
The laminate of the present invention can be used as a packaging material for sliced cheese. An embodiment of a method for manufacturing a packaging material will be described below with reference to FIGS. 2A and 2B.
First, the heat seal layer of the present invention and the seal layer are overlapped and heat-sealed to form a primary seal portion 21 to form a cylindrical laminate. Next, the melted cheese is poured into the inside of the cylindrical laminate and rolled.
After rolling, the roller discharges the cheese at the left and right end portions of the packaging material, and heat-seals the portion, that is, the portion where the sealing layers are overlapped, to form the secondary sealing portion 22.
Next, the laminate filled with sliced cheese is water-cooled and drained with air and / or a brush to produce the laminate of the present invention.
Further, the heat-sealed left and right ends may be cut to a desired length.

When the packaging material is opened, the heat-sealing layer is separated by coagulation failure in the primary sealing portion, and the delamination layer and the sealing layer are peeled off in the secondary sealing portion.

From the viewpoint of achieving both sealability and ease of opening, the strength of the primary seal portion (strength that causes aggregation failure of the heat seal layer) is preferably 0.5 N / 15 mm or more and 4 N / 15 mm or less, and 0. It is more preferably 7N / 15mm or more and 3.2N / 15mm or less. The strength of the secondary seal portion (strength at which delamination occurs between the delamination layer and the seal layer) is preferably 0.5 N / 15 mm or more and 3 N / 15 mm or less, preferably 0.7 N / 15 mm. As mentioned above, it is more preferable that it is 2.5 N / 15 mm or less.
The strength of the primary seal portion and the secondary seal portion can be measured by Tensilon in accordance with JIS K 7125.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
A 12 μm-thick biaxially stretched PET film with both sides treated with corona was attached to a delivery roll of a plasma chemical vapor deposition apparatus, and one surface was oxidized to a thickness of 200 nm using hexamethyldisiloxane (HMDSO) as a raw material. A silicon vapor deposition film was formed. Next, the surface of this thin-film film was subjected to plasma treatment.

A coating liquid for forming a gas barrier layer having the following composition was applied onto the vapor-filmed film and dried by heating at 100 ° C. for 30 seconds to form a gas barrier layer having a thickness of 1 μm.
(Coating liquid for forming gas barrier layer)
-EVOH (ethylene copolymer rate 29%) 0.61% by mass
-PVA 1.52% by mass
Alkoxysilane 11.46% by mass
(Made by Colcourt Co., Ltd., Product name: Ethyl silicate 40)
・ Silane coupling agent 0.05% by mass
・ Aluminum acetylacetone 0.02% by mass
-Isopropyl alcohol 34.80% by mass
・ Ion-exchanged water 51.41% by mass
・ Acetic acid 0.13% by mass

A polyolefin-based anchor coating agent (manufactured by Unitika Ltd., trade name: DA-1015JB) was applied onto the gas barrier layer and dried to form an anchor layer.

Random polypropylene (manufactured by Prime Polymer Co., Ltd., trade name: F329RA) and low-density polyethylene (manufactured by Japan Polyethylene Corporation, trade name: KC570S) are melt-coextruded onto the anchor layer and delaminated to a thickness of 8 μm. A layer and a seal layer having a thickness of 4 μm were formed.

A water-repellent coating agent having the following composition (MFG Cheese Wanis (Toyo Ink Co., Ltd.)) was applied to the other surface of the PET film and dried to form a water-repellent layer having a thickness of 1 μm.

A heat sealant containing an ethylene-vinyl acetate copolymer (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Icadine S sealant NT (D)) is applied and dried so as to be surface-sequential to the water-repellent layer. A heat-sealed layer having a thickness of 1 μm was formed, and the laminate of the present invention was obtained.

Comparative Example 1
A laminated body was obtained in the same manner as in Example 1 except that the thin-film deposition film and the gas barrier layer were not formed.

<< Barrier evaluation test >>
Under the conditions of a temperature of 40 ° C. and a humidity of 75% RH, the water vapor transmission rate and the oxygen permeability were measured using a barrier property measuring device manufactured by MOCON. The measurement results are summarized in Table 1.
Further, using a filling machine manufactured by Netec (trade name: FP2000), the laminates obtained in the above Examples and Comparative Examples were filled and packaged with cheese at a rotation speed of 400 rpm.
The sealing temperature was 150 ° C. After filling, it was allowed to stand in an environment of temperature 25 ° C. and humidity 50% RH for 7 days.
When the state of the cheese after standing was visually confirmed, the cheese filled and packaged in the laminate of Example 1 did not change, whereas the cheese filled and packaged in the laminate of Comparative Example 1 was clear. Dryness was seen.

<< Seal strength evaluation test >>
Using a filling machine manufactured by Netec (trade name: FP2000), the laminates obtained in the above Examples and Comparative Examples were filled and packaged with cheese at a rotation speed of 400 rpm. The sealing temperature was 150 ° C. After filling, the primary seal strength and the secondary seal strength were measured by Tensilon in accordance with JIS K 7125 and summarized in Table 1.

<< Water repellency evaluation test >>
Using a filling machine manufactured by Netec (trade name: FP2000), the laminates obtained in the above Examples and Comparative Examples were filled and packaged with cheese at a rotation speed of 400 rpm. The sealing temperature was 150 ° C. After filling, the contact angles of the laminates of Examples and Comparative Examples in which cheese was filled and packaged were measured by the contact angle method according to JIS R 3257, and are summarized in Table 1.
In addition, in accordance with JIS P 8147, a laminate of Examples and Comparative Examples filled and packaged with cheese is set in a friction angle measuring machine, and 0.1 ml of water droplets are dropped on the laminate to determine the inclination angle at which the water droplets slide down. The measurements were taken and summarized in Table 1.

10: Laminated body, 11: Heat seal layer, 12: Base material, 13: Vapor film, 14: Gas barrier layer, 15: Delamination layer, 16: Seal layer, 17: Water repellent layer, 18: Anchor layer

Claims (10)

A laminate comprising a heat-sealing layer, a base material, a vapor-film deposition film, a gas barrier layer, a delamination layer, and a sealing layer in this order . The laminate according to claim 1, further comprising a water-repellent layer so as to be surface-sequential to the heat-sealed layer of the base material. The laminate according to claim 2, further comprising an anchor layer between the base material and the water-repellent layer and the heat-sealing layer. Any one of claims 1 to 3, wherein the gas barrier layer is a layer formed by a coating liquid for forming a gas barrier layer containing a gas barrier resin and an alkoxide represented by the general formula ^R1 _nm (OR ² ) _m . The laminate according to item 1.
(In the equation, M represents a metal atom, m represents an integer of 1 or more, and n represents 0 or an integer of 1 or more.) The laminate according to claim 4, wherein the coating liquid for forming a gas barrier layer contains polyvinyl alcohol and / or an ethylene / vinyl alcohol copolymer. The laminate according to any one of claims 1 to 5, wherein the vapor-deposited film contains silicon oxide or aluminum oxide. The laminate according to any one of claims 1 to 6, wherein the delamination layer contains polypropylene. The laminate according to any one of claims 1 to 7, wherein the delamination layer has a thickness of 1 μm or more and 100 μm or less. The laminate according to claim 2 or 3, wherein the water-repellent layer contains a polyamide-based resin and a cellulosic-based resin. A packaging material for sliced cheese comprising the laminate according to any one of claims 1 to 9.

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