Laminated film, packaging material and package

Abstract

To provide a laminated film having an improved balance of water vapor barrier properties and oxygen barrier properties.SOLUTION: There is provided a laminated film including: a substrate layer containing an ethylene polymer (A), an undercoat layer, and an inorganic layer containing an inorganic material (B), in this order, in which in an infrared absorption spectrum of the undercoat layer, when a maximum peak height in an absorption band range of 3000 cm-1 or more and 3600 cm-1 or less is defined as P1 and a maximum peak height in the absorption band range of 1500 cm-1 or more and 1900 cm-1 or less is defined as P2, a peak height ratio P2 / P1 is 0.065 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminated film, a packaging material, and a package. [Background technology]

[0002] In the field of food packaging, films with gas barrier properties are being developed to ensure long-term storage of contents.

[0003] Patent Document 1 describes a gas barrier film characterized by forming a coating film, the main components of which are a water-soluble polymer A, a water-soluble or water-dispersible urethane resin, and an inorganic layered compound, on at least one surface of a thermoplastic resin substrate film, with the objective of providing a gas barrier film that has gas barrier properties under high humidity conditions, adhesion between the coating film and the substrate film, and durability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-151265 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a laminated film having an improved balance of water vapor barrier properties and oxygen barrier properties. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, they have found that, in a laminate film comprising, in this order, a substrate layer containing an ethylene-based polymer, an undercoat layer, and an inorganic layer containing an inorganic material, there is a correlation between the peak height ratio defined under predetermined conditions in the infrared absorption spectrum of the undercoat layer and the performance balance of the water vapor barrier property and oxygen barrier property of the laminate film. Based on the above findings, the present inventors have conducted further extensive research and found that by setting the peak height ratio within a predetermined range, the performance balance of the water vapor barrier property and oxygen barrier property of the laminate film can be improved, thereby completing the present invention.

[0007] That is, according to the present invention, there are provided the following laminated film, packaging material, and packaging body.

[0008] [1] a substrate layer containing an ethylene polymer (A); an undercoat layer; an inorganic layer containing an inorganic material (B); In this order, In the infrared absorption spectrum of the undercoat layer, Absorption band 3000cm -1 More than 3600cm -1 The maximum peak height in the following range is defined as P1, Absorption band 1500cm -1 over 1900cm -1 When the maximum peak height in the following range is P2, A laminated film having a peak height ratio P2 / P1 of 0.065 or more. [2] The laminate film according to [1], wherein the undercoat layer contains one or more selected from the group consisting of polyurethane resins, poly(meth)acrylic resins, and cured products of mixtures containing polycarboxylic acids, polyamines, and polyvalent metal compounds. [3] The laminated film according to [1] or [2], wherein the undercoat layer contains a crosslinking agent. [4] the undercoat layer contains a polyurethane-based resin, The laminated film according to [3], wherein the crosslinking agent contains a compound having a carbodiimide group. [5] the undercoat layer contains a poly(meth)acrylic resin, The laminated film according to [3], wherein the crosslinking agent contains a compound having an oxazoline group. [6] The laminated film according to any one of [1] to [5], wherein the undercoat layer is provided so as to be in direct contact with the inorganic layer. [7] The laminated film according to any one of [1] to [6], wherein the thickness of the undercoat layer is 0.01 μm or more and 5.0 μm or less. [8] The laminated film according to any one of [1] to [7], wherein the base layer includes a uniaxially stretched film layer or a biaxially stretched film layer. [9] The laminated film according to any one of [1] to [8], wherein the content of the ethylene polymer (A) in the base layer is 75% by mass or more and 100% by mass or less, when the entire base layer is taken as 100% by mass.

[10] The laminated film according to any one of [1] to [9], wherein the ethylene polymer (A) contains polyethylene.

[11] The laminated film according to

[10] , wherein the polyethylene comprises one or more selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).

[12] The density of the ethylene polymer (A) is 0.910 g / cm 3 More than 0.970g / cm 3 The laminated film according to any one of [1] to

[11] below:

[13] The laminated film according to any one of [1] to

[12] , wherein the thickness of the base layer is 5 μm or more and 100 μm or less.

[14] The laminated film according to any one of [1] to

[13] , wherein the ratio of the thickness of the base layer to the total thickness of the laminated film is 20% or more and less than 100%.

[15] The laminated film according to any one of [1] to

[14] , wherein the inorganic material (B) contains one or more selected from the group consisting of aluminum and aluminum oxide.

[16] The substrate layer is a core layer containing the ethylene polymer (A); a skin layer provided so as to be in direct contact with at least one surface of the core layer; The laminated film according to any one of [1] to

[15] , comprising:

[17] The laminated film according to

[16] , wherein the skin layer contains an ethylene polymer (C).

[18] The moisture permeability measured by the following method is 1.7g / (m 2 The laminated film according to any one of [1] to

[17] , wherein the maximum temperature is less than 100°C (days). (Measurement method) An adhesive is applied to one side of a 50 μm thick LLDPE film. The laminated film and the LLDPE film are then laminated together so that the inorganic layer side of the laminated film is in contact with the adhesive-coated side of the LLDPE film, yielding a multilayer film. The resulting multilayer film is then folded back so that the LLDPE film faces inward, and the two sides are heat-sealed to form a bag. Calcium chloride is then placed inside the resulting bag. The other side of the bag is then heat-sealed to reduce the surface area to 0.01 m. 2 The resulting bag is then stored at 40°C and 90% RH for 300 hours. The weight of the calcium chloride is measured before and after storage, and the moisture permeability is calculated from the difference.

[19] The laminated film according to any one of [1] to

[18] , which is a packaging film.

[20] A packaging material comprising the laminated film according to any one of [1] to

[19] . [twenty one] The packaging material according to

[20] , further comprising a coating layer on at least one surface of the laminated film. [twenty two]

[20] or

[21] , and a packaging material according to and an item within the packaging material. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a laminated film having an improved balance of water vapor barrier property and oxygen barrier property. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a laminated film according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view schematically illustrating an example of a laminated film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic diagrams and do not correspond to actual dimensional proportions. In this specification, "A to B" indicating a numerical range means A or more and B or less unless otherwise specified. In this specification, when comparing laminate films that have the same configuration except for the undercoat layer, if the performance balance between the water vapor barrier property and the oxygen barrier property is improved, it is determined that the performance balance between the water vapor barrier property and the oxygen barrier property has been improved.

[0012] (Laminated film) 1 and 2 are cross-sectional views schematically illustrating an example of a laminate film according to the present embodiment. As shown in FIGS. 1 and 2, the laminate film 100 of the present embodiment includes a substrate layer 10 containing an ethylene polymer (A), an undercoat layer 30, and an inorganic layer 50 containing an inorganic material (B), in this order. In the infrared absorption spectrum of the undercoat layer 30, the laminate film 100 has an absorption band of 3000 cm -1 More than 3600cm -1 The maximum peak height in the following range is P1, and the absorption band is 1500 cm -1 over 1900cm -1 When the maximum peak height in the following range is P2, the peak height ratio P2 / P1 is 0.065 or more.

[0013] The present inventors have found that in a laminate film 100 comprising, in this order, a base layer 10 containing an ethylene polymer (A), an undercoat layer 30, and an inorganic layer 50 containing an inorganic material (B), there is a correlation between the peak height ratio P2 / P1 in the infrared absorption spectrum of the undercoat layer 30 and the performance balance between the water vapor barrier property and the oxygen barrier property of the laminate film 100. As a result of further intensive studies based on the above findings, the present inventors have found that the performance balance between the water vapor barrier property and the oxygen barrier property of the laminate film 100 can be improved by setting the peak height ratio P2 / P1 within the above range, and have thus completed the present invention.

[0014] The peak height ratio P2 / P1 is 0.065 or more, preferably 0.100 or more, more preferably 0.200 or more, even more preferably 0.500 or more, even more preferably 1.000 or more, even more preferably 2.000 or more, even more preferably 2.300 or more, even more preferably 3.000 or more, even more preferably 4.000 or more, and even more preferably 4.500 or more. By setting the peak height ratio P2 / P1 within the above range, the performance balance between the water vapor barrier property and the oxygen barrier property of the laminated film 100 can be further improved. The upper limit of the peak height ratio P2 / P1 is not particularly limited, and may be, for example, 10,000 or less, 1,000 or less, 100 or less, 80 or less, or 70 or less. Furthermore, from the viewpoint of further improving the performance balance between the water vapor barrier property and the oxygen barrier property of the laminated film 100, the peak height ratio P2 / P1 is preferably 0.065 or more and 10,000 or less, more preferably 0.100 or more and 1,000 or less, even more preferably 0.200 or more and 100 or less, even more preferably 0.500 or more and 100 or less, even more preferably 1.000 or more and 100 or less, even more preferably 2.000 or more and 80 or less, even more preferably 2.300 or more and 80 or less, even more preferably 3.000 or more and 70 or less, even more preferably 4.000 or more and 70 or less, and even more preferably 4.500 or more and 70 or less.

[0015] The mechanism by which the performance balance between the water vapor barrier property and the oxygen barrier property of the laminated film 100 can be improved by setting the peak height ratio P2 / P1 in the above range is not entirely clear, but based on the studies of the present inventors, it is presumed to be as follows: In the infrared absorption spectrum of the undercoat layer 30, the absorption band at 3000 cm -1 More than 3600cm -1 The peaks seen below are thought to be due to OH stretching vibration or NH stretching vibration. Also, the absorption band at 1500 cm -1 over 1900cm -1 The peaks seen below are thought to be due to C=O stretching vibration.

[0016] That is, in the infrared absorption spectrum of the undercoat layer 30, the absorption band at 3000 cm -1 More than 3600cm -1 The maximum peak height P1 in the following range is thought to represent an indicator of the amount of functional groups with OH stretching vibration or NH stretching vibration absorption. -1 over 1900cm -1 The maximum peak height P2 in the following range is considered to represent an index of the amount of functional groups present that have absorption due to C=O stretching vibration. Therefore, it can be evaluated that the larger the peak height ratio P2 / P1, the smaller the amount of functional groups present in the undercoat layer 30 that have absorption due to OH stretching vibration or NH stretching vibration. It can also be evaluated that the smaller the peak height ratio P2 / P1, the larger the amount of functional groups present in the undercoat layer 30 that have absorption due to OH stretching vibration or NH stretching vibration.

[0017] From the viewpoint of improving the performance balance between the water vapor barrier property and the oxygen barrier property of the laminate film 100, it is considered preferable that the amount of functional groups with absorption of OH stretching vibration or NH stretching vibration, which easily absorb moisture from the atmosphere, present in the undercoat layer 30 is relatively small. This is because it is thought that if the undercoat layer 30 absorbs moisture, swelling of the undercoat layer 30 will occur, deteriorating the barrier property. If the peak height ratio P2 / P1 is within the above range, it can be evaluated that the amount of functional groups with absorption of OH stretching vibration or NH stretching vibration present in the undercoat layer 30 is a predetermined value or less, and it is therefore considered possible to improve the performance balance between the water vapor barrier property and the oxygen barrier property of the laminate film 100.

[0018] In this embodiment, the peak height ratio P2 / P1 can be controlled by appropriately selecting the type and amount of resin contained in the undercoat layer 30, the method for preparing the resin composition, etc. For example, the peak height ratio P2 / P1 can be increased by increasing the content of poly(meth)acrylic resin having an ester bond in the repeating unit.

[0019] In this embodiment, the maximum peak heights P1 and P2 are measured in the following manner. First, the infrared absorption spectrum of the surface of the undercoat layer 30 is measured by infrared total reflection measurement (ATR method). The measurement is performed at room temperature (25°C), with a Ge prism (incident angle 45 degrees) and a measurement wavelength of 4000 cm -1 ~600cm -1 , resolution 4.0cm -1 The number of times of accumulation is 100. Then, in the obtained infrared absorption spectrum, -1 Measurement points at 3000cm -1 The measurement points at 3000 cm and 3000 cm are connected by a straight line (baseline), and the difference spectrum between the obtained infrared absorption spectrum and the baseline is obtained, and this spectrum is designated as spectrum S1. -1 More than 3600cm -1 The maximum peak height in the following range is defined as P1. Similarly, in the obtained infrared absorption spectrum, -1 Measurement points at 1500cm -1 The measurement points at 1500 cm and 1500 cm are connected by a straight line (baseline), and the difference spectrum between the obtained infrared absorption spectrum and the baseline is obtained, and this spectrum is designated as spectrum S2. -1 over 1900cm -1 The maximum peak height in the following range is defined as P2.

[0020] The undercoat layer 30 preferably contains one or more materials selected from the group consisting of polyurethane resins, poly(meth)acrylic resins, and cured products of mixtures containing polycarboxylic acids, polyamines, and polyvalent metal compounds, thereby further improving the balance of water vapor barrier properties and oxygen barrier properties of the laminate film 100.

[0021] (Polyurethane resin) The polyurethane resin can be obtained, for example, by subjecting a polyol having two or more alcoholic hydroxyl groups in one molecule to a polyaddition reaction with a polyisocyanate. The polyol preferably includes one or more polyols selected from the group consisting of polyether polyols, polycarbonate polyols, and polyester polyols, and more preferably includes one or more polyols selected from the group consisting of polycarbonate polyols and polyester polyols. That is, the polyurethane-based resin preferably contains one or more polyurethane-based resins selected from the group consisting of polyether-type polyurethane-based resins, polycarbonate-type polyurethane-based resins, and polyester-type polyurethane-based resins, and more preferably contains one or more polyurethane-based resins selected from the group consisting of polycarbonate-type polyurethane-based resins and polyester-type polyurethane-based resins.

[0022] Examples of polyether polyols include polymers obtained by ring-opening polymerization of one or more cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin, etc., using a compound having an active hydrogen atom as a catalyst, etc. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.

[0023] The polycarbonate polyol can be obtained by reacting a carbonate compound with a diol. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and diethylene carbonate. Examples of diols include aliphatic diols which may be substituted with a lower alcohol; alicyclic diols such as cyclohexanediol and hydrogenated xylylene glycol; and aromatic diols such as xylylene glycol. Aliphatic diols are preferred, and aliphatic diols having a carbon chain length of 4 to 9, such as 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, heptanediol, octanediol, and nonanediol, are more preferred.

[0024] The polyester polyol can be obtained by condensing a low molecular weight diol with a dicarboxylic acid. Examples of low molecular weight diols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and 1,4-butanediol, and examples thereof include ethylene glycol, propylene glycol, and 1,4-butanediol. Examples of dicarboxylic acids include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and brassylic acid; and aromatic dibasic acids such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Among these, aliphatic dibasic acids are preferred, including dibasic acids with a methylene chain length of 4 to 8, such as adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

[0025] Examples of polyisocyanates include chain aliphatic diisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; aliphatic diisocyanates having a cyclic structure such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, and dicyclohexylmethane 4,4'-diisocyanate; aliphatic diisocyanates having an aromatic ring such as xylylene diisocyanate and tetramethylxylylene diisocyanate; aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate; and modified products of these diisocyanates (carbodiimide-, uretdione-, and uretoimine-containing modified products, etc.), with aliphatic diisocyanates and aromatic diisocyanates being preferred.

[0026] Examples of reaction solvents for the polyaddition reaction include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, ethyl acetate, toluene, and xylene. In the polyaddition reaction, a chain extender or a reaction terminator may be used in combination, if necessary. The use of a chain extender can increase the molecular weight. Examples of chain extenders include polyols and polyamines, and examples of reaction terminators include monoalcohols and monoamines. The polyurethane resin is preferably used as an emulsion, and the emulsion may contain a dispersant such as a surfactant, if necessary. That is, the polyurethane resin is preferably a water-dispersible polyurethane resin.

[0027] The water-dispersible polyurethane resin is preferably a self-emulsifying polyurethane resin in which a hydrophilic group such as a carboxylate (-COONa, etc.) or a sulfonate (-SO3Na, etc.) is introduced into the main chain or side chain of the polyurethane resin. As the polyurethane resin, commercially available water-dispersible polyurethane resins can also be used.

[0028] Examples of commercially available water-dispersible polyurethane resins include those manufactured by Mitsui Chemicals, Inc., under the trade names Takelac WS4000, Takelac WS5100, Takelac WS4022, Takelac WBP341A, and Takelac W6010.

[0029] (Poly(meth)acrylic resin) The poly(meth)acrylic resin is preferably (meth)acrylic acid and salts thereof; (meth)acrylic acid such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate. ) alkyl esters or cycloalkyl esters of acrylic acid; unsaturated amide compounds such as (meth)acrylamide and diacetone acrylamide; nitrile group-containing monomers such as acrylonitrile and methacrylonitrile; and hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, or a polymer or copolymer thereof. The poly(meth)acrylic resin more preferably contains a copolymer of (meth)acrylic acid and an alkyl ester of (meth)acrylic acid, and even more preferably contains a copolymer of acrylic acid and an alkyl ester of acrylic acid, which can further improve the balance of the water vapor barrier property and oxygen barrier property of the laminate film 100.

[0030] The poly(meth)acrylic resin preferably includes an aqueous poly(meth)acrylic resin. The aqueous poly(meth)acrylic resin is a resin containing alkyl(meth)acrylate as a main component, and is preferably a water-soluble or water-dispersible resin containing, for example, 40 to 95 mol% of alkyl(meth)acrylate components and, for example, 5 to 60 mol% of copolymerizable vinyl monomer components having functional groups. Examples of functional groups in the vinyl monomers include carboxyl groups, acid anhydride groups, sulfonic acid groups or salts thereof, amide groups or alkylolated amide groups, amino groups (including substituted amino groups), alkylolated amino groups or salts thereof, hydroxyl groups, and epoxy groups, with carboxyl groups, acid anhydride groups, and epoxy groups being particularly preferred. Two or more of these groups may be contained in the resin. Examples of the alkyl group of the alkyl (meth)acrylate include methyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-ethylhexyl, lauryl, stearyl, and cyclohexyl. Examples of compounds having a carboxyl group or an acid anhydride include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and the like, as well as alkali metal salts, alkaline earth metal salts, and ammonium salts thereof, and further include anhydrides such as maleic anhydride. Examples of compounds having a sulfonic acid group or a salt thereof include vinyl sulfonic acid, styrene sulfonic acid, and metal salts (e.g., sodium salts) and ammonium salts of these sulfonic acids. Examples of the compound having an amide group or an alkylolated amide group include acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, and methylolated methacrylamide. Examples of compounds having the above amino group, alkylolated amino group, or salts thereof include diethylaminoethyl vinyl ether, 2-aminoethyl vinyl ether, 3-aminopropyl vinyl ether, 2-aminobutyl vinyl ether, and dimethylaminoethyl methacrylate. Examples of the compound having a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, β-hydroxyvinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, etc. Examples of the compound having an epoxy group include glycidyl acrylate, glycidyl methacrylate, etc. Further, examples of compounds that can be used in combination include acrylonitrile, styrenes, butyl vinyl ether, maleic acid mono- or dialkyl esters, fumaric acid mono- or dialkyl esters, itaconic acid mono- or dialkyl esters, vinyl acetate, vinylpyridine, vinylpyrrolidone, and vinyltrimethoxysilane.

[0031] (Cured product of a mixture containing a polycarboxylic acid, a polyamine, and a polyvalent metal compound) The polycarboxylic acid contained in the mixture is a polymer having two or more carboxy groups in the molecule. The polycarboxylic acid preferably includes one or more selected from the group consisting of polymers and copolymers of α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, cinnamic acid, 3-hexenoic acid, and 3-hexenedioic acid; and copolymers of the above-mentioned α,β-unsaturated carboxylic acids with esters such as ethyl esters, and olefins such as ethylene. The polycarboxylic acid more preferably contains one or more selected from the group consisting of polymers of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, and cinnamic acid, and copolymers thereof, even more preferably contains one or more selected from the group consisting of polyacrylic acid and polymethacrylic acid, and even more preferably contains polyacrylic acid, which can further improve the balance of water vapor barrier property and oxygen barrier property of the laminate film 100.

[0032] The polyamine contained in the mixture is a polymer having two or more amino groups in the molecule. The polyamine preferably includes one or more selected from the group consisting of aliphatic polyamines such as polyallylamine, polyvinylamine, polyethyleneimine, and poly(trimethyleneimine); and polyamides such as polylysine and polyarginine, and more preferably includes polyethyleneimine. This allows the laminated film 100 to have a better balance of water vapor barrier properties and oxygen barrier properties.

[0033] When the polycarboxylic acid contained in the mixture includes one or more selected from the group consisting of polyacrylic acid and polymethacrylic acid, the polyamine contained in the mixture preferably includes polyethyleneimine.

[0034] The polyvalent metal compounds contained in the mixture are, for example, metals and metal compounds belonging to Groups 2 to 13 of the periodic table. The polyvalent metal compound preferably contains one or more selected from the group consisting of divalent or higher metals such as magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and aluminum (Al), and oxides, hydroxides, halides, carbonates, phosphates, phosphites, hypophosphites, sulfates, and sulfites of these metals; more preferably contains one or more selected from the group consisting of magnesium oxide, calcium oxide, barium oxide, zinc oxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, and zinc hydroxide; even more preferably contains one or more selected from the group consisting of zinc oxide and zinc hydroxide; and even more preferably contains zinc oxide. This allows the undercoat layer 30 to be formed more uniformly, thereby further improving the balance of the water vapor barrier property and oxygen barrier property of the laminated film 100.

[0035] When the undercoat layer 30 contains a cured product of a mixture containing a polycarboxylic acid, a polyamine, and a polyvalent metal compound, the ratio (the number of moles of amino groups derived from the polyamine in the cured product) / (the number of moles of -COO- groups derived from the polycarboxylic acid in the cured product) is preferably 20 / 100 or more and 90 / 100 or less, more preferably 25 / 100 or more and 85 / 100 or less, even more preferably 30 / 100 or more and 80 / 100 or less, even more preferably 35 / 100 or more and 75 / 100 or less, and even more preferably 40 / 100 or more and 70 / 100 or less. By setting the ratio (number of moles of amino groups derived from polyamine in the cured product) / (number of moles of -COO- groups derived from polycarboxylic acid in the cured product) within the above range, the undercoat layer 30 can be formed more uniformly, thereby further improving the performance balance between the water vapor barrier property and the oxygen barrier property of the laminate film 100.

[0036] The mixture of this embodiment may contain components other than the polycarboxylic acid, polyamine, and polyvalent metal compound. Examples of such components include polyphosphate compounds or their salts, ammonium carbonate salts, surfactants, crosslinking agents, lubricants, slip agents, antiblocking agents, antistatic agents, antifogging agents, pigments, dyes, inorganic or organic fillers, etc. Examples of crosslinking agents include epoxysilane compounds, carbodiimide compounds, and isocyanate compounds.

[0037] (Crosslinking agent) The undercoat layer 30 preferably contains a crosslinking agent, which improves the balance of performance such as heat resistance, water resistance, and hydrolysis resistance. The crosslinking agent may be an external crosslinking agent that is a component separate from the resin, or an internal crosslinking agent that preliminarily introduces reactive sites that form a crosslinked structure into the molecular structure of the resin.

[0038] The crosslinking agent preferably contains one or more compounds selected from the group consisting of compounds having a carbodiimide group, compounds having an oxazoline group, compounds having an isocyanate group, compounds having an epoxy group, melamine resins, and compounds having a silanol group, more preferably contains one or more compounds selected from the group consisting of compounds having a carbodiimide group, compounds having an oxazoline group, and compounds having an isocyanate group, and even more preferably contains one or more compounds selected from the group consisting of compounds having a carbodiimide group and compounds having an oxazoline group.

[0039] The compound having a carbodiimide group is a carbodiimide-modified product of polyisocyanate, and can be obtained as a polycarbodiimide compound, for example, by subjecting polyisocyanate to a decarboxylation condensation reaction in the presence of a known carbodiimide catalyst. The compound having a carbodiimide group includes, for example, one or more selected from the group consisting of tetramethylxylylene diisocyanate-based carbodiimides, 4,4'-methylenebis(cyclohexylisocyanate)-based carbodiimides, and pentamethylene diisocyanate-based carbodiimides. In addition, compounds having a carbodiimide group are also commercially available, and examples thereof include Carbodilite V-02, Carbodilite V-02-L2, Carbodilite SV-02, Carbodilite V-04, Carbodilite V-10, Carbodilite SW-12G, Carbodilite E-02, Carbodilite E-03A, and Carbodilite E-05 (manufactured by Nisshinbo Chemical Inc.); Luplanet MM-103 and XTB-3003 (manufactured by BASF); and Stabacksol P (manufactured by Sumitomo Bayer Urethane Co., Ltd.).

[0040] Compounds having an oxazoline group include, for example, oxazoline group-containing aqueous polymers. Examples of oxazoline group-containing aqueous polymers include polymers obtained by polymerizing addition-polymerizable oxazoline group-containing monomers alone or with other monomers. Examples of addition-polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination. Among these, 2-isopropenyl-2-oxazoline is preferred. The other monomer may be any monomer copolymerizable with the addition-polymerizable oxazoline group-containing monomer, and examples thereof include acrylates or methacrylates such as alkyl acrylates and alkyl methacrylates (the alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl groups); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid, and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, and the like); unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkyl acrylate ... Examples of suitable monomers include unsaturated amides such as diacrylamide and N,N-dialkyl methacrylates (the alkyl group may be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a cyclohexyl group, or the like); vinyl esters such as those in which a polyalkylene oxide is added to the ester moiety of vinyl acetate, vinyl propionate, acrylic acid, or methacrylic acid; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride; and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene. One or more of these monomers may be used.

[0041] Examples of compounds having an isocyanate group include water-dispersible polyisocyanates. The water-dispersible polyisocyanate is a polyisocyanate that can be dispersed in water, and examples thereof include polyisocyanates having an alkylene oxide group having 2 to 3 carbon atoms as a repeating unit. The water-dispersible polyisocyanate includes, for example, one or more selected from the group consisting of water-dispersible blocked polyisocyanates and water-dispersible non-blocked polyisocyanates, and preferably includes a water-dispersible non-blocked polyisocyanate, and more preferably includes a water-dispersible non-blocked polyisocyanate having a polyalkylene oxide group. In addition, water-dispersible polyisocyanates are also available as commercially available products, such as Takenate WD-720, Takenate WD-725, Takenate WD-726, Takenate WD-220, Takenate XWD-HS7, and Takenate XWD-HS30 (manufactured by Mitsui Chemicals, Inc.); Aquanate 100, Aquanate 110, Aquanate 200, and Aquanate 210 (manufactured by Nippon Polyurethane Industry Co., Ltd.); Duranate WB40-100 and Duranate WT20-100 (manufactured by Asahi Kasei Chemicals Corporation); Bayhydur 3100 and Bayhydur XP2487 / 1 (manufactured by Bayer MaterialScience); and Basonat HW100 and Basonat HA100 (manufactured by BASF).

[0042] When the undercoat layer 30 contains a polyurethane resin, the crosslinking agent preferably contains a compound having a carbodiimide group. In this case, the content of the compound having a carbodiimide group is preferably 1 part by mass to 50 parts by mass, more preferably 3 parts by mass to 30 parts by mass, even more preferably 5 parts by mass to 25 parts by mass, and even more preferably 5 parts by mass to 15 parts by mass, per 100 parts by mass of the polyurethane resin. By setting the content of the compound having a carbodiimide group within the above range, the performance balance of the undercoat layer 30, such as heat resistance, water resistance, and hydrolysis resistance, can be improved.

[0043] When the undercoat layer 30 contains a poly(meth)acrylic resin, the crosslinking agent preferably contains a compound having an oxazoline group. In this case, the content of the compound having an oxazoline group is preferably 1 part by mass to 25 parts by mass, more preferably 5 parts by mass to 20 parts by mass, and even more preferably 7.5 parts by mass to 15 parts by mass, per 100 parts by mass of the poly(meth)acrylic resin. By setting the content of the compound having an oxazoline group within the above range, the performance balance of the undercoat layer 30, such as heat resistance, water resistance, and hydrolysis resistance, can be improved.

[0044] From the viewpoint of further improving the balance of water vapor barrier property and oxygen barrier property, the undercoat layer 30 is preferably provided so as to be in direct contact with the inorganic layer 50. Furthermore, the manufacturing process of the laminated film 100 can be simplified.

[0045] The thickness of the undercoat layer 30 is preferably 0.01 μm to 5.0 μm, more preferably 0.03 μm to 3.0 μm, even more preferably 0.04 μm to 2.0 μm, and even more preferably 0.05 μm to 1.0 μm. By setting the thickness of the undercoat layer 30 within this range, the performance balance between the water vapor barrier property and the oxygen barrier property of the laminated film 100 can be further improved.

[0046] The undercoat layer 30 may contain various additives, such as tackifiers, heat stabilizers, weather stabilizers, antioxidants, ultraviolet absorbers, lubricants, slip agents, nucleating agents, antiblocking agents, antistatic agents, antifogging agents, pigments, dyes, and inorganic or organic fillers, as needed, within the scope that does not impair the purpose of this embodiment.

[0047] (base material layer) The substrate layer 10 contains an ethylene polymer (A). The ethylene polymer (A) preferably contains polyethylene. The polyethylene contained in the ethylene polymer (A) preferably contains one or more polyethylenes selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), more preferably one or more polyethylenes selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), and even more preferably one or more polyethylenes selected from the group consisting of linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE). This allows the laminate film 100 to have a good balance of various properties, such as thermal dimensional stability, film-formability, heat resistance, water vapor barrier properties, mechanical properties, and rigidity.

[0048] Here, low-density polyethylene (LDPE) is 0.910 g / cm 3 More than 0.930g / cm 3 Medium density polyethylene (MDPE) refers to polyethylene having a density less than 0.930 g / cm 3 More than 0.942g / cm 3 High density polyethylene (HDPE) refers to polyethylene having a density less than 0.942 g / cm 3 It refers to polyethylene with a density of 100% or more. Low-density polyethylene with little branching is called linear low-density polyethylene (LLDPE).

[0049] The content of the ethylene polymer (A) in the base layer 10 is preferably 75% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 85% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, even more preferably 95% by mass to 100% by mass, and even more preferably 98% by mass to 100% by mass. By setting the content of the ethylene polymer (A) in the base layer 10 to the above-mentioned lower limit or more, a good balance of various properties such as thermal dimensional stability, film-forming ability, heat resistance, mechanical properties, and rigidity can be achieved. Furthermore, by setting the content of the ethylene polymer (A) in the base layer 10 to the above-mentioned upper limit or less, a good balance of processability and continuous productivity can be achieved.

[0050] The density of the ethylene polymer (A), measured in accordance with JIS K 7112:1999, is preferably 0.910 g / cm 3 More than 0.970g / cm 3 or less, more preferably 0.915 g / cm 3 More than 0.965g / cm 3 or less, more preferably 0.920 g / cm 3 More than 0.960g / cm 3 or less, more preferably 0.925 g / cm 3 More than 0.955g / cm 3 or less, more preferably 0.930 g / cm 3 More than 0.950g / cm 3 or less, more preferably 0.935 g / cm 3 More than 0.945g / cm 3 By adjusting the density of the ethylene polymer (A) to the above lower limit or more, it is possible to achieve a good balance among various properties such as thermal dimensional stability, film-forming ability, heat resistance, mechanical properties, rigidity, etc. Furthermore, by adjusting the density of the ethylene polymer (A) to the above upper limit or less, it is possible to improve the film-forming ability. When two or more types of polymers are used as the ethylene polymer (A), the density of a mixture obtained by melt blending two or more types of ethylene polymers by a known method can be used.

[0051] The melt mass flow rate (MFR) of the ethylene polymer (A), measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g, is preferably 0.1 g / 10 min to 5.0 g / 10 min, more preferably 0.2 g / 10 min to 4.5 g / 10 min, even more preferably 0.4 g / 10 min to 4.0 g / 10 min, even more preferably 0.6 g / 10 min to 3.5 g / 10 min, and even more preferably 0.8 g / 10 min to 3.0 g / 10 min. By adjusting the melt mass flow rate (MFR) of the ethylene polymer (A) to be equal to or greater than the above lower limit, the balance of performance among fluidity, film-forming ability, and thermal dimensional stability can be improved. Furthermore, by setting the melt mass flow rate (MFR) of the ethylene polymer (A) to the above upper limit or less, the stiffness of the laminated film 100 can be improved while improving the balance of film-forming properties and thermal dimensional stability. When two or more types of polymers are used as the ethylene polymer (A), the MFR of a mixture obtained by melt blending two or more types of polymers by a known method can be used.

[0052] The melting point of the ethylene polymer (A) measured by differential scanning calorimetry (DSC) is preferably 90° C. or higher and 150° C. or lower, more preferably 100° C. or higher and 150° C. or lower, even more preferably 110° C. or higher and 140° C. or lower, even more preferably 120° C. or higher and 140° C. or lower, and still more preferably 125° C. or higher and 135° C. By adjusting the melting point of the ethylene polymer (A) to fall within the above range, the balance of properties such as film-forming ability, thermal dimensional stability, heat resistance, water vapor barrier property, mechanical properties, rigidity, bag-forming ability, and flowability can be improved. When two or more types of polymers are used as the ethylene polymer (A), the melting point of the ethylene polymer (A) is the peak temperature of the maximum melting peak.

[0053] The base layer 10 preferably includes a stretched film, more preferably a uniaxially stretched film layer or a biaxially stretched film layer, which allows the laminated film 100 to have a good balance of various properties such as thermal dimensional stability, film formability, heat resistance, barrier properties, mechanical properties, and rigidity.

[0054] The thickness of the substrate layer 10 is preferably 5 μm to 100 μm, more preferably 5 μm to 50 μm, even more preferably 10 μm to 40 μm, even more preferably 12 μm to 30 μm, and even more preferably 15 μm to 25 μm. By setting the thickness of the substrate layer 10 within the above range, the performance balance of the laminated film 100 can be improved, including thermal dimensional stability, film-forming properties, water vapor barrier properties, cost, mechanical properties, transparency, bag-forming properties, handleability, appearance, and light weight.

[0055] The ratio of the thickness of the base layer 10 to the total thickness of the laminate film 100 is preferably 20% or more and less than 100%, more preferably 40% or more and less than 100%, even more preferably 60% or more and 99% or less, and even more preferably 80% or more and 99% or less. By setting the ratio of the thickness of the base layer 10 to the total thickness of the laminate film 100 within the above range, the performance balance of the laminate film 100 can be improved, including thermal dimensional stability, film-forming properties, water vapor barrier properties, cost, mechanical properties, transparency, bag-forming properties, handleability, appearance, and light weight.

[0056] As shown in Fig. 2, the base layer 10 preferably includes a core layer 11 containing the ethylene polymer (A) and a skin layer 13 provided so as to be in direct contact with at least one surface of the core layer 11. This simplifies the manufacturing process for the base layer 10 even when the base layer 10 includes multiple layers. Also, as shown in Fig. 2, the laminate film 100 preferably includes the core layer 11, the skin layer 13, an undercoat layer 30, and an inorganic layer 50, in this order.

[0057] The content of the ethylene polymer (A) in the core layer 11 is preferably 75% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 85% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, even more preferably 95% by mass to 100% by mass, and even more preferably 98% by mass to 100% by mass. By setting the content of the ethylene polymer (A) in the core layer 11 to the above-mentioned lower limit or more, a good balance of various properties such as thermal dimensional stability, film-forming ability, heat resistance, mechanical properties, and rigidity can be achieved. Furthermore, by setting the content of the ethylene polymer (A) in the core layer 11 to the above-mentioned upper limit or less, a good balance of properties such as processability and continuous productivity can be achieved.

[0058] The skin layer 13 preferably contains an ethylene polymer (C). The ethylene polymer (C) preferably contains polyethylene. The polyethylene contained in the ethylene polymer (C) preferably contains one or more polyethylenes selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), more preferably one or more polyethylenes selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), and even more preferably one or more polyethylenes selected from the group consisting of linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE). This allows for a good balance of various properties, such as thermal dimensional stability, film-forming ability, heat resistance, water vapor barrier properties, mechanical properties, and rigidity.

[0059] The content of the ethylene polymer (C) in the skin layer 13 is preferably 75% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 85% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, even more preferably 95% by mass to 100% by mass, and even more preferably 98% by mass to 100% by mass, based on the total mass of the skin layer 13. By ensuring that the content of the ethylene polymer (C) in the skin layer 13 is equal to or greater than the above-mentioned lower limit, a good balance can be achieved among various performances such as thermal dimensional stability, film-forming ability, heat resistance, mechanical properties, and rigidity. Furthermore, by ensuring that the content of the ethylene polymer (C) in the skin layer 13 is equal to or less than the above-mentioned upper limit, a good balance can be achieved among the performances of processability and continuous productivity.

[0060] The base layer 10 may contain various additives, such as tackifiers, heat stabilizers, weather stabilizers, antioxidants, ultraviolet absorbers, lubricants, slip agents, nucleating agents, antiblocking agents, antistatic agents, antifogging agents, pigments, dyes, and inorganic or organic fillers, as needed, within the scope that does not impair the purpose of this embodiment.

[0061] (Inorganic layer) The inorganic layer 50 includes an inorganic material (B). The inorganic material (B) preferably includes one or more elements selected from the group consisting of elements from Group 2A of the Periodic Table, such as beryllium, magnesium, calcium, strontium, and barium; transition elements from the Periodic Table, such as titanium, zirconium, ruthenium, hafnium, and tantalum; elements from Group 2B of the Periodic Table, such as zinc; elements from Group 3A of the Periodic Table, such as aluminum, gallium, indium, and thallium; elements from Group 4A of the Periodic Table, such as silicon, germanium, and tin; and elements from Group 6A of the Periodic Table, such as selenium and tellurium, either as simple substances or oxides (the names of the Periodic Table groups are shown in the old CAS format). To achieve a good balance of barrier properties, cost, and the like, the inorganic material (B) more preferably includes one or more elements selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride, aluminum oxide, and aluminum, even more preferably includes one or more elements selected from the group consisting of aluminum and aluminum oxide, and even more preferably includes aluminum.

[0062] The thickness of the inorganic layer 50 is preferably more than 0 nm and not more than 500 nm, more preferably 0.1 nm or more and 100 nm or less, and even more preferably 1 nm or more and 50 nm or less. By setting the thickness of the inorganic layer 50 within this range, the performance balance of the laminated film 100 can be improved, including thermal dimensional stability, film-forming properties, water vapor barrier properties, cost, mechanical properties, transparency, bag-forming properties, handleability, appearance, and light weight.

[0063] (Physical properties of laminated film) The moisture permeability of the multilayer film described below is preferably 1.7 g / (m 2 ·day), more preferably less than 1.6g / (m 2 ·day) or less, more preferably 1.5g / (m 2 ·day) or less, more preferably 1.4g / (m 2 By setting the moisture permeability of the multilayer film within the above range, the water vapor barrier properties of the multilayer film including the laminate film 100 can be improved. The lower limit of the moisture permeability of the multilayer film is not particularly limited, but is, for example, 0.001 g / (m 2 ·day) or more, and 2 ·day) or more, and 2 ·day) or more.

[0064] The oxygen permeability of the multilayer film described below is preferably 14.2 mL / (m 2 ·day·MPa), more preferably less than 12.0mL / (m 2 ·day·MPa) or less, more preferably 10.0 mL / (m 2 ·day·MPa) or less, more preferably 9.0 mL / (m 2 By setting the oxygen permeability of the multilayer film within the above range, the oxygen barrier properties of the multilayer film including the laminate film 100 can be improved. The lower limit of the oxygen permeability of the multilayer film is not particularly limited, but is, for example, 0.01 mL / (m 2 ·day·MPa) or more, and2 ·day·MPa) or more, and 1.0mL / (m 2 ·day·MPa) or more.

[0065] In this embodiment, the moisture permeability and oxygen permeability of the multilayer film are measured by the following method. An adhesive is applied to one side of a 50 μm thick LLDPE film, and then the laminated film 100 and the LLDPE film are laminated together so that the surface of the laminated film 100 facing the inorganic layer 50 comes into contact with the adhesive-coated surface of the LLDPE film, thereby obtaining a multilayer film. Next, the obtained multilayer film is folded back so that the LLDPE film is on the inside, and the two sides are heat-sealed to form a bag. Calcium chloride is then placed in the resulting bag. The other side of the bag is then heat-sealed to form a bag with a surface area of ​​0.01 m. 2 The resulting bag is then stored at 40°C and 90% RH for 300 hours. The weight of the calcium chloride is measured before and after storage, and the moisture permeability is calculated from the difference. The oxygen permeability (mL / (m 2 ·day·MPa)) is measured in accordance with JIS K7126:2006 under conditions of 20°C and 90% RH.

[0066] (Laminated film manufacturing method) The laminated film 100 can be obtained, for example, by the following method. First, an ethylene-based resin composition containing an ethylene-based polymer (A) is extruded into a film, and then stretched to obtain the base layer 10. When the base layer 10 contains multiple layers, the multiple layers are laminated together and then stretched. The molding apparatus and molding conditions are not particularly limited, and conventionally known molding apparatus and molding conditions can be used. Examples of molding apparatus that can be used include a T-die extruder, a multilayer T-die extruder, an inflation molding machine, and a multilayer inflation molding machine. The conditions for the stretching treatment can be those used for producing known polyethylene films. For example, in the sequential biaxial stretching method, the MD stretching temperature is preferably set to a range of 100°C to 145°C, more preferably 110°C to 140°C, and even more preferably 120°C to 135°C, and the TD stretching temperature is preferably set to a range of 110°C to 190°C, more preferably 120°C to 170°C. The MD stretch ratio is set to a range of 4.5 to 7 times, and the TD stretch ratio is set to a range of 9 to 11 times. Here, the stretching temperature must be set at three stages: preheating temperature (temperature at which the raw film is heated before stretching), stretching temperature (temperature at which stretching is performed), and heat setting temperature (temperature at which heat setting (annealing) is performed after stretching). The temperatures from preheating to heat setting can be within the above range. In other words, the temperatures from the preheating stage onward can be set to approximately the same as those for stretching and heat setting.

[0067] Next, the undercoat layer 30 is formed on the base material layer 10. The method for forming the undercoat layer 30 is not particularly limited, but for example, the undercoat layer 30 can be formed by applying a resin composition for forming the undercoat layer 30 to the surface of the base material layer 10 and then polymerizing the composition by ultraviolet irradiation, heating, or the like. In particular, when the undercoat layer 30 contains a cured product of a mixture containing a polycarboxylic acid, a polyamine, and a polyvalent metal compound, the undercoat layer 30 can be formed, for example, by the following method. First, a volatile base is added to a polycarboxylic acid to completely or partially neutralize the carboxyl groups of the polycarboxylic acid. A polyvalent metal salt compound and a carbonate-based ammonium salt are then mixed to form metal salts on all or part of the carboxyl groups of the polycarboxylic acid neutralized with the volatile base and on the carboxyl groups of the polycarboxylic acid not neutralized with the volatile base. A polyamine compound is then added to obtain a coating material. The coating material is then applied to the surface of a substrate layer and dried and cured to form an undercoat layer 30.

[0068] Next, the inorganic layer 50 is formed on the undercoat layer 30. The method for forming the inorganic layer 50 is not particularly limited, and it can be formed by, for example, a vacuum process such as a vacuum deposition method, a sputtering method, or a plasma vapor deposition method (CVD method), or a sol-gel process.

[0069] (Laminated film applications / packaging materials / packaging bodies) Specifically, the laminated film 100 of this embodiment can be suitably used as a packaging film. The laminated film 100 of this embodiment can be suitably used as a packaging material. That is, the packaging material of this embodiment includes the laminated film 100. When used as a packaging material, the laminate film 100 of this embodiment may be used alone, or other layers may be laminated on at least one surface of the laminate film 100 to form the packaging material. The other layers preferably include one or more selected from the group consisting of a coating layer, a substrate layer, and an inorganic layer, and more preferably include a coating layer. From the viewpoint of ease of recycling, the other layers are preferably formed from a polyethylene-based resin. Furthermore, the packaging material of this embodiment can be suitably used for a package. The package is used, for example, for packaging an item. Specifically, the package of this embodiment includes the packaging material of this embodiment and an item inside the packaging material. In particular, the packaging of this embodiment can be suitably used as a food package, and is used for packaging food. Specifically, the packaging of this embodiment includes the packaging material of this embodiment and food inside the packaging material. The food to be packaged in the food packaging is not particularly limited, but examples thereof include baked goods, rice crackers, snacks, rice seasonings, grain powders, and the like. Depending on the application, only a portion of the package may be made of the packaging material of this embodiment, or substantially the entire package may be made of the packaging material of this embodiment.

[0070] The content of the ethylene polymer in the packaging material of this embodiment, when the entire packaging material is taken as 100% by mass, is preferably 50% by mass or more and less than 100% by mass, more preferably 70% by mass or more and less than 100% by mass, even more preferably 80% by mass or more and 99.9% by mass or less, even more preferably 90% by mass or more and 99.9% by mass or less, even more preferably 95% by mass or more and 99.5% by mass or less, and even more preferably 99.0% by mass or more and 99.5% by mass or less. This means that the packaging material is composed of almost a single material (monomaterial), which reduces the work of separating the materials that make up the packaging material and improves the recyclability of the packaging material.

[0071] The polyethylene content in the packaging material of this embodiment, when the entire packaging material is taken as 100% by mass, is preferably 50% by mass or more and less than 100% by mass, more preferably 70% by mass or more and less than 100% by mass, even more preferably 80% by mass or more and less than 99.9% by mass, even more preferably 90% by mass or more and less than 99.9% by mass, even more preferably 95% by mass or more and less than 99.8% by mass, and even more preferably 99.0% by mass or more and less than 99.8% by mass. This means that the packaging material is composed of almost a single material (monomaterial), which reduces the work of separating the materials that make up the packaging material and improves the recyclability of the packaging material.

[0072] There are no particular limitations on the method for producing a package from the laminate film 100 or packaging material, and any method known in the field of packaging materials / packages, such as heat sealing or fusing, can be used as appropriate.

[0073] The laminated film 100 according to this embodiment is preferably used for packaging that requires good barrier properties. The form of the packaging can be, for example, a two-sided bag or a standing pouch (pouch packaging).

[0074] When a package (such as a food packaging bag) is constructed using the laminate film 100 of this embodiment or a packaging material, it is preferable that the corona-treated surface is the inner surface and the non-corona-treated surface is the outer surface. Furthermore, as described above, when another layer is laminated on the laminate film 100, it is preferable that the layer is laminated on the corona-treated surface. In other words, when a laminate using the laminate film 100 of this embodiment is used for a package (such as a food packaging bag), it is preferable that the laminate film 100 of this embodiment is the outermost layer of the package.

[0075] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0076] The present embodiment will be described in detail below with reference to examples and comparative examples, but the present embodiment is not limited to the descriptions of these examples.

[0077] 1.Raw materials The raw materials used to prepare the substrate layer are shown below. LLDPE1: Linear low-density polyethylene (density: 0.918 g / cm 3 , MFR: 3.8g / 10min, Melting point: 116℃) LLDPE2: Linear low-density polyethylene (density: 0.928 g / cm 3 , MFR: 1.9g / 10min, Melting point: 126℃) LLDPE3: Linear low-density polyethylene (density: 0.931 g / cm 3 , MFR: 3.2g / 10min, Melting point: 123℃) HDPE1: High density polyethylene (density: 0.958 g / cm 3 , MFR: 1.0g / 10min, Melting point: 133℃) HDPE2: High density polyethylene (density: 0.949 g / cm 3 , MFR: 1.1g / 10min, Melting point: 130℃) The density was measured in accordance with JIS K 7112:1999. The MFR was measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160g. The melting point was measured using a differential scanning calorimeter (DSC). Specifically, using a differential scanning calorimeter (product name: Q200DSC manufactured by TA Instruments), a first differential scanning calorimeter measurement was performed under a nitrogen gas flow, consisting of a process of increasing the temperature from -50°C to 230°C at a heating rate of 10°C / min and a process of decreasing the temperature from 230°C to -50°C at a heating rate of 10°C / min, and a second differential scanning calorimeter measurement was performed consecutively, consisting of a process of increasing the temperature from -50°C to 230°C at a heating rate of 10°C / min. The peak temperature of the maximum endothermic peak in the DSC curve in the second measurement was taken as the melting point (°C).

[0078] 2. Preparation of the substrate layer Skin layer 1, core layer, and skin layer 2 were extrusion-molded with the compositions and layer configurations shown in Table 1. They were then stretched under the conditions shown in Table 1. The surface of skin layer 1 was then corona-treated to produce MDOPE, HDBOPE, and LLBOPE, respectively. Each film had a thickness of 25 μm. The extrusion molding conditions and stretching treatment conditions are as follows. Extrusion molding machine: 60 mmφ multi-layer T-die extrusion molding machine (screw: L / D=27, manufactured by Screw Seiki Co., Ltd.) Extrusion temperature setting: 230-250°C, Processing speed: 15m / min (winding speed) In Table 1, the notation "A / B / C" for the stretching temperature means "preheating temperature (temperature at which the raw film is heated before stretching) / stretching temperature (temperature during stretching) / heat setting temperature (temperature during heat setting (annealing) after stretching)." The relaxation ratio refers to the maximum stretching width in the device settings divided by the tenter exit width.

[0079] [Table 1]

[0080] 3. Preparation and evaluation of laminated film Example 1 (1) Formation of the undercoat layer A resin composition having the following composition was applied to the corona-treated surface of the MDOPE using a Mayer bar and dried to form an undercoat layer having a thickness of 0.1 μm after drying. (composition) Main ingredient: Polyurethane resin aqueous dispersion (aliphatic polyester polyurethane resin, glass transition temperature: 115°C, solid content: 30% by mass) Crosslinker: Compound with carbodiimide group (water-soluble type, solid content: 40% by mass, NCN equivalent: 430) Blending ratio: The crosslinking agent was blended into the main component so that the compound having a carbodiimide group (solid content) in the crosslinking agent was 7.2 parts by mass per 100 parts by mass of polyurethane resin (solid content) in the main component.

[0081] (2) Infrared spectroscopy (IR measurement) The infrared absorption spectrum of the surface of the undercoat layer was measured by infrared total reflection (ATR) measurement using an infrared microscope (manufactured by JASCO, product name: FT / IR-4X) at room temperature (25°C), a Ge prism (incident angle: 45°), and a measurement wavelength of 4000 cm -1 ~600cm -1 , resolution 4.0cm -1 The test was performed under the condition of 100 times of accumulation. In the obtained infrared absorption spectrum, 3600 cm -1 Measurement points at 3000cm -1The measurement points at 3000 cm and 3000 cm were connected with a straight line (baseline), and the difference spectrum between the obtained infrared absorption spectrum and the baseline was obtained, which was designated as spectrum S1. -1 More than 3600cm -1 The maximum peak height in the following range was defined as P1. Similarly, in the obtained infrared absorption spectrum, -1 Measurement points at 1500cm -1 The measurement points at 1500 cm and 1500 cm were connected by a straight line (baseline), and the difference spectrum between the obtained infrared absorption spectrum and the baseline was obtained, which was designated as spectrum S2. -1 over 1900cm -1 The maximum peak height in the following range was defined as P2.

[0082] (3) Formation of inorganic layer Aluminum was evaporated onto the undercoat layer formed in (1) above by using a resistance heating method, forming a 40 nm thick aluminum film as an inorganic layer, and obtaining a laminated film.

[0083] (4) Moisture permeability An adhesive (12 parts by mass of a polyester adhesive (Mitsui Chemicals, Inc., product name: Takelac A-310), 1 part by mass of an isocyanate curing agent (Mitsui Chemicals, Inc., product name: Takenate A-3), and 7 parts by mass of ethyl acetate) was applied to one side of a 50 μm-thick unstretched LLDPE film (manufactured by Mitsui Chemicals Tohcello, Inc., product name: TUXMCS). After drying, the laminate film and the LLDPE film were laminated (dry laminated) so that the inorganic layer side of the laminate film was in contact with the adhesive-coated surface of the LLDPE film, yielding a multilayer film. The resulting multilayer film was then folded over so that the LLDPE film was on the inside, and the two sides were heat-sealed to form a bag. Calcium chloride was then placed inside the resulting bag. The other side of the bag was then heat-sealed to form a bag with a surface area of ​​0.01 m. 2The bags were then stored at 40°C and 90% RH for 300 hours. The weight of the calcium chloride was measured before and after storage, and the moisture permeability was calculated from the difference.

[0084] (5) Oxygen permeability In the same manner as in the measurement of moisture permeability, the laminated film and the LLDPE film were laminated (dry laminated) to obtain a multilayer film. The oxygen permeability (mL / (m) of the obtained multilayer film was then measured. 2 ·day·MPa) was measured in accordance with JIS K7126:2006 under conditions of 20°C and 90% RH.

[0085] Example 2 A laminated film was obtained in the same manner as in Example 1, except that the resin composition used to form the undercoat layer was a base resin without blending a crosslinking agent.

[0086] Example 3 A laminated film was obtained in the same manner as in Example 1, except that only a polyurethane resin aqueous dispersion (polycarbonate-type polyurethane resin, glass transition temperature: 90°C, solid content: 30% by mass) was used as the resin composition for forming the undercoat layer.

[0087] Example 4 A laminated film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition for forming the undercoat layer. (composition) Main ingredient: Water-based acrylic resin (acrylic acid alkyl copolymer emulsion, carboxyl group content: 0.9 mmol / g, solid content: 30% by mass, manufactured by Toagosei Co., Ltd., product name: ET-410) Crosslinker: Oxazoline group-containing aqueous polymer (water-soluble type, oxazoline group content: 7.7 mmol / g, glass transition temperature: 90°C, solid content: 10% by mass, manufactured by Nippon Shokubai Co., Ltd., product name: WS-300) Blending ratio: The crosslinking agent was blended into the main component so that the oxazoline group-containing aqueous polymer (solid content) in the crosslinking agent was 14.4 parts by mass per 100 parts by mass of the aqueous acrylic resin (solid content) in the main component.

[0088] Example 5 Polyacrylic acid (weight average molecular weight: 800,000), 10 mass% aqueous ammonia, and purified water were mixed so that the ammonia concentration was 250 equivalent % relative to the carboxyl groups of the polyacrylic acid, to obtain an aqueous solution of ammonium polyacrylate with a concentration of 7.29 mass %. Next, zinc oxide and ammonium carbonate were added to the resulting aqueous ammonium polyacrylate solution, and the mixture was stirred to obtain a mixed solution (1-A). The amount of zinc oxide added was such that the ratio (moles of zinc oxide in coating material A) / (moles of -COO- groups in polyacrylic acid in coating material A) was 0.475. The amount of ammonium carbonate added was such that the ratio (moles of ammonium carbonate in coating material A) / (moles of zinc oxide in coating material A) was 1.5. Next, polyethyleneimine (number average molecular weight: 10,000) was added to purified water to obtain a 10% by mass aqueous polyethyleneimine solution. Next, purified water was added to low-polymerized ammonium polyphosphate (manufactured by Amada Co., Ltd., product number: water-soluble ammonium polyphosphate flame retardant NNA20, P2O5 content 59%) to obtain a 25% by mass aqueous solution of low-polymerized ammonium polyphosphate. Next, the mixed solution (1-A), the polyethyleneimine aqueous solution, and the low-polymerized ammonium polyphosphate aqueous solution as a phosphorus introduction source were mixed in a ratio such that (the number of moles of amino groups contained in polyethyleneimine in coating material A) / (the number of moles of -COO- groups contained in polyacrylic acid in coating material A) was 0.55, and (the number of moles of P contained in polyphosphate compound or its salt in coating material A) / (the number of moles of -COO- groups contained in polyacrylic acid in coating material A) was 0.025, to obtain mixed solution (2-A). Furthermore, purified water was added to the above mixed solution (2-A) so that the solids concentration was 1.5% by mass, and after stirring until a uniform solution was obtained, a surfactant (polyoxyethylene lauryl ether) was added to the mixed solution (2-A) so that the solids concentration was 0.3% by mass, to prepare coating material A. Coating material A was applied to the corona-treated surface of MDOPE with a Mayer bar and dried to form an undercoat layer with a thickness of 0.1 μm after drying.

[0089] (Comparative Example 1) A laminated film was obtained in the same manner as in Example 1, except that only polyvinyl alcohol (completely saponified, degree of saponification: 99.0 to 99.4 mol%) was used as the resin composition for forming the undercoat layer.

[0090] (Comparative Example 2) A laminated film was obtained in the same manner as in Example 1, except that after corona treatment was performed on the surface on the skin layer 1 side, aluminum was vapor-deposited on the corona-treated surface without forming an undercoat layer. Note that infrared spectroscopy measurement was performed on the corona-treated surface before aluminum was vapor-deposited.

[0091] Examples 6 to 9 Laminated films were obtained in the same manner as in Examples 1, 2, 4, and 5, except that HDBOPE was used instead of MDOPE as the base layer.

[0092] (Comparative Example 3) Except for using HDBOPE instead of MDOPE as the base layer, a laminated film was obtained in the same manner as in Comparative Example 2. Note that infrared spectroscopy measurement was performed on the corona-treated surface before aluminum was vapor-deposited.

[0093] Example 10 A laminated film was obtained in the same manner as in Example 1, except that LLBOPE was used instead of MDOPE as the base layer.

[0094] Comparative Example 4 Except for using LLBOPE instead of MDOPE as the base layer, a laminated film was obtained in the same manner as in Comparative Example 2. Note that infrared spectroscopy measurement was performed on the corona-treated surface before aluminum was vapor-deposited.

[0095] The evaluation results of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 2. The evaluation results of Examples 6 to 9 and Comparative Example 3 are shown in Table 3. The evaluation results of Example 10 and Comparative Example 4 are shown in Table 4.

[0096] [Table 2]

[0097] [Table 3]

[0098] [Table 4]

[0099] As shown in Table 2, when the laminate films of Examples 1 to 5 were used, multilayer films with improved water vapor barrier properties and oxygen barrier properties were obtained compared to when the laminate film of Comparative Example 1 was used. Furthermore, when the laminate films of Examples 1 to 5 were used, multilayer films with improved oxygen barrier properties were obtained compared to when the laminate film of Comparative Example 2 was used.

[0100] As shown in Table 3, when the laminate films of Examples 6 to 9 were used, multilayer films with improved water vapor barrier properties and oxygen barrier properties were obtained compared to when the laminate film of Comparative Example 3 was used.

[0101] As shown in Table 4, when the laminated film of Example 10 was used, a multilayer film with improved water vapor barrier properties and oxygen barrier properties was obtained compared to when the laminated film of Comparative Example 4 was used. [Explanation of symbols]

[0102] 10 Base material layer 11 Core layer 13 Skin layer 30 Undercoat layer 50 Inorganic layer 100 Laminated Film

Claims

1. a substrate layer containing an ethylene polymer (A); an undercoat layer; an inorganic layer containing an inorganic material (B); In this order, In the infrared absorption spectrum of the undercoat layer, Absorption band 3000 cm －１ More than 3600cm －１ The maximum peak height in the following range is P １ year, Absorption band 1500 cm －１ More than 1900cm －１ The maximum peak height in the following range is P ２ When Peak height ratio P ２ / P １ A laminated film having a modulus of 0.065 or more.

2. 2. The laminate film according to claim 1, wherein the undercoat layer comprises one or more selected from the group consisting of polyurethane resins, poly(meth)acrylic resins, and cured products of mixtures containing polycarboxylic acids, polyamines, and polyvalent metal compounds.

3. The laminated film according to claim 1 or 2, wherein the undercoat layer contains a crosslinking agent.

4. the undercoat layer contains a polyurethane-based resin, The laminated film according to claim 3 , wherein the crosslinking agent comprises a compound having a carbodiimide group.

5. the undercoat layer contains a poly(meth)acrylic resin, The laminated film according to claim 3 , wherein the crosslinking agent comprises a compound having an oxazoline group.

6. 6. The laminated film according to claim 1, wherein the undercoat layer is provided so as to be in direct contact with the inorganic layer.

7. The laminated film according to any one of claims 1 to 6, wherein the undercoat layer has a thickness of 0.01 µm or more and 5.0 µm or less.

8. The laminated film according to any one of claims 1 to 7, wherein the substrate layer comprises a uniaxially stretched film layer or a biaxially stretched film layer.

9. The laminate film according to any one of claims 1 to 8, wherein the content of the ethylene polymer (A) in the base layer is 75% by mass or more and 100% by mass or less, when the entire base layer is taken as 100% by mass.

10. The laminated film according to any one of claims 1 to 9, wherein the ethylene polymer (A) contains polyethylene.

11. The laminate film according to claim 10, wherein the polyethylene comprises one or more selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).

12. The density of the ethylene polymer (A) is 0.910 g / cm ３ 0.970g / cm or more ３ The laminate film according to any one of claims 1 to 11, wherein:

13. The laminated film according to any one of claims 1 to 12, wherein the thickness of the substrate layer is 5 µm or more and 100 µm or less.

14. The laminate film according to any one of claims 1 to 13, wherein the ratio of the thickness of the base layer to the total thickness of the laminate film is 20% or more and less than 100%.

15. The laminate film according to any one of claims 1 to 14, wherein the inorganic material (B) comprises one or more selected from the group consisting of aluminum and aluminum oxide.

16. The substrate layer is a core layer containing the ethylene polymer (A); a skin layer provided so as to be in direct contact with at least one surface of the core layer; The laminated film according to any one of claims 1 to 15, comprising:

17. The laminate film according to claim 16 , wherein the skin layer comprises an ethylene polymer (C).

18. The moisture permeability measured by the following method is 1.7 g / (m ２ The laminated film according to any one of claims 1 to 17, wherein the film thickness is less than 1 / 2 day. (Measurement method) An adhesive is applied to one side of a 50 μm thick LLDPE film. The laminated film and the LLDPE film are then laminated together so that the inorganic layer side of the laminated film is in contact with the adhesive-coated side of the LLDPE film, yielding a multilayer film. The resulting multilayer film is then folded back so that the LLDPE film faces inward, and the two sides are heat-sealed to form a bag. Calcium chloride is then placed inside the resulting bag. The other side of the bag is then heat-sealed to reduce the surface area to 0.01 m. ２ The resulting bag is then stored for 300 hours under conditions of 40°C and 90% RH. The weight of the calcium chloride is measured before and after storage, and the moisture permeability is calculated from the difference.

19. The laminated film according to any one of claims 1 to 18, which is a packaging film.

20. A packaging material comprising the laminate film according to any one of claims 1 to 19.

21. 21. The packaging material of claim 20, further comprising a coating layer on at least one side of the laminate film.

22. The packaging material according to claim 20 or 21; and an item within the packaging material.

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