Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B29/00—Layered products comprising a layer of paper or cardboard
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
  • C08G18/46—Polycondensates having carboxylic or carbonic ester groups in the main chain having heteroatoms other than oxygen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/67—Unsaturated compounds having active hydrogen
  • C08G18/68—Unsaturated polyesters

Definitions

• the present invention relates to laminates and packaging materials based on paper.
• Gas barrier materials are used in a variety of fields to prevent the intrusion of gases such as oxygen from the outside air.
• packaging materials used to package food and beverages are required to protect the contents from various distribution processes, storage such as refrigeration, and processing such as heat sterilization, as well as to have oxygen barrier properties that prevent the intrusion of oxygen from the outside in order to suppress oxidation for the purpose of long-term food storage, carbon dioxide barrier properties, and barrier properties against various aroma components, etc.
• Known packaging materials that use paper as a base material and have gas barrier properties include a paper base material that contains 50% to 100% by mass of kaolin with an aspect ratio of 10 or more relative to the total pigment, and a gas barrier layer that contains a polyvinyl alcohol resin as a binder resin (see, for example, Patent Document 1), and a packaging material that has a base paper having an undercoat layer and a layer containing a vinylidene chloride copolymer on top of the base paper with a specific moisture permeability, thickness, and density (see, for example, Patent Document 2).
• the present invention has been made in consideration of these circumstances, and aims to provide a paper laminate and packaging material that has excellent drying properties with low energy compared to aqueous coating agents, does not require a sealing layer, and has good gas barrier properties.
• the present invention includes a paper substrate and a gas barrier coating layer disposed on the paper substrate,
• the gas barrier coat layer is a cured coating film of a two-component curing coating agent that contains polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a polyhydric alcohol, polyester polyol (A2) having an isocyanuric ring, and polyester polyol (A3) having a polymerizable carbon-carbon double bond, an isocyanate compound (B), an organic solvent (C), and a drying aid (D).
• polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a polyhydric alcohol, polyester polyol (A2) having an isocyanuric ring, and polyester polyol (A3) having a
• the present invention also provides a paper substrate, a heat seal film, a gas barrier coating layer disposed on the surface of the paper substrate facing the heat seal film, and an adhesive layer disposed between the gas barrier coating layer and the heat seal film
• the gas barrier coat layer is a cured coating film of a two-component curing coating agent that contains polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a polyhydric alcohol, polyester polyol (A2) having an isocyanuric ring, and polyester polyol (A3) having a polymerizable carbon-carbon double bond, an isocyanate compound (B), an organic solvent (C), and a drying aid (D).
• polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a poly
• the present invention also provides a paper substrate, a heat seal layer which is a dried coating film of a heat seal agent, and a gas barrier coat layer
• the gas barrier coat layer is a cured coating film of a two-component curing coating agent that contains polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a polyhydric alcohol, polyester polyol (A2) having an isocyanuric ring, and polyester polyol (A3) having a polymerizable carbon-carbon double bond, an isocyanate compound (B), an organic solvent (C), and a drying aid (D).
• polyester polyol (A) including at least one selected from polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-orienting aromatic polycarboxylic acid and a polyhydric alcohol, polyester polyol (A2) having an isocyanuric
• the present invention also provides a paper packaging material made of the laminate described above.
• the present invention makes it possible to provide a paper laminate and packaging material that has excellent drying properties with low energy compared to aqueous coating agents, does not require a sealing layer, and has good gas barrier properties.
• the coating agent used in the present invention is a two-component curing type coating agent containing a polyester polyol (A), an isocyanate compound (B), an organic solvent (C), and a drying aid (D).
• the coating agent used in the present invention exhibits gas barrier properties by being applied and dried, and in the present invention, "gas” mainly refers to oxygen.
• the drying aid (D) may be present in the polyol composition (I) together with the polyester polyol (A), or may be prepared separately from the polyol composition (I) and the polyisocyanate composition (II) and mixed with them immediately before coating.
• the organic solvent (C) may be contained in only one of the polyol composition (I) or the polyisocyanate composition (II), or may be present in both.
• polyester polyol (A) is a reaction product of a monomer composition (A') containing a polycarboxylic acid and a polyhydric alcohol, and contains at least one of a polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid including an ortho-oriented aromatic polycarboxylic acid with a polyhydric alcohol, a polyester polyol (A2) having an isocyanuric ring, and a polyester polyol (A3) having a polymerizable carbon-carbon double bond.
• A1 obtained by polycondensation of a polycarboxylic acid including an ortho-oriented aromatic polycarboxylic acid with a polyhydric alcohol
• A2 having an isocyanuric ring
• A3 having a polymerizable carbon-carbon double bond
• the ortho-oriented polycarboxylic acid used in the synthesis of polyester polyol (A1) includes orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene carboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring.
• substituents examples include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimido group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, or a naphthyl group.
• the polycarboxylic acid used in the synthesis of polyester polyol (A1) may contain a polycarboxylic acid other than an ortho-oriented polycarboxylic acid.
• polycarboxylic acids other than the ortho-oriented polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecane dicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentane dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid; terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid
• the polycarboxylic acid contains a polycarboxylic acid other than an ortho-oriented polycarboxylic acid, it is preferable that the proportion of the ortho-oriented polycarboxylic acid in the total amount of the polycarboxylic acid is 70 to 100 mass%.
• the polyhydric alcohol used in the synthesis of polyester polyol (A1) preferably contains at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, and cyclohexanedimethanol, and more preferably contains at least one selected from ethylene glycol and glycerin.
• the polyhydric alcohol may be used in combination with other polyhydric alcohols than those mentioned above.
• the polyhydric alcohol include aliphatic diols such as 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol; trihydric or higher polyhydric alcohols such as tris(2-hydroxyethyl)isocyanurate, 1,2,4-butanetriol, pentaerythritol, and dipentaerythritol; hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, hisphenol F, and tetramethylbiphenol; ethylene oxide-ex
• polyester polyol (A1) has three or more hydroxyl groups (for convenience, referred to as polyester polyol (a1)), some of the hydroxyl groups may be modified with acid groups.
• polyester polyols are also referred to as polyester polyols (A1') below.
• the polyester polyol (A1') is obtained by reacting the polyester polyol (a1) with a polycarboxylic acid or its acid anhydride.
• the ratio of hydroxyl groups modified with the polycarboxylic acid is preferably 1/3 or less of the hydroxyl groups in the polyester polyol (a1).
• polycarboxylic acids used for modification include, but are not limited to, succinic anhydride, maleic acid, fumaric acid, 1,2-cyclohexanedicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, phthalic anhydride, 2,3-naphthalenedicarboxylic anhydride, trimellitic anhydride, oleic acid, and sorbic acid.
• the polyester polyol (A2) can be obtained, for example, by reacting a triol having an isocyanuric ring with a polycarboxylic acid including an ortho-oriented aromatic polycarboxylic acid and a polyhydric alcohol.
• triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.
• the ortho-oriented aromatic polycarboxylic acid, polycarboxylic acid, and polyhydric alcohol can be the same as those used for the polyester polyol (A1).
• triol compound having an isocyanuric ring it is preferable to use 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.
• ortho-oriented aromatic polycarboxylic acid it is preferable to use orthophthalic anhydride.
• polyhydric alcohol it is preferable to use ethylene glycol.
• Polyester polyol (A3) is obtained by using components having polymerizable carbon-carbon double bonds as polyvalent carboxylic acids and polyhydric alcohols.
• polyvalent carboxylic acids having a polymerizable carbon-carbon double bond examples include maleic anhydride, maleic acid, fumaric acid, 4-cyclohexene-1,2-dicarboxylic acid and its acid anhydride, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid and its acid anhydride, etc. It is presumed that the smaller the number of carbon atoms, the less the molecular chain becomes flexible and the less oxygen permeable it is, so maleic anhydride, maleic acid, and fumaric acid are preferred.
• An example of the polyhydric alcohol having a polymerizable carbon-carbon double bond is 2-butene-1,4-diol.
• polycarboxylic acids and polyhydric alcohols not having a polymerizable carbon-carbon double bond may be used in combination.
• polycarboxylic acids and polyhydric alcohols the same ones as those used for polyester polyols (A1) and (A2) can be used.
• the polycarboxylic acid it is preferable to use at least one selected from the group consisting of succinic acid, 1,3-cyclopentanedicarboxylic acid, orthophthalic acid, orthophthalic anhydride, and isophthalic acid, and it is more preferable to use at least one orthophthalic acid and its anhydride.
• polyhydric alcohol it is preferable to use at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol, and it is more preferable to use ethylene glycol.
• the hydroxyl value of polyester polyol (A) is preferably 1 mgKOH/g or more and 350 mgKOH/g or less.
• the acid value is preferably 200 mgKOH/g or less.
• the hydroxyl value of polyester polyol (A) can be measured by the hydroxyl value measurement method described in JIS-K0070, and the acid value can be measured by the acid value measurement method described in JIS-K0070.
• the number average molecular weight of polyester polyol (A) is particularly preferably 400 to 5000, since this provides a crosslinking density that provides an excellent balance between adhesion to the substrate and gas barrier properties.
• the number average molecular weight is more preferably 500 to 2500.
• the number average molecular weight is calculated from the obtained hydroxyl value and the number of functional groups of the designed hydroxyl group.
• the glass transition temperature of the polyester polyol (A) is preferably 10°C or higher and 80°C or lower, more preferably 20°C or higher and 60°C or lower, and even more preferably 35°C or higher and 60°C or lower, in view of the balance between adhesion to the substrate and gas barrier properties.
• the polyester polyol (A) may be a polyester polyurethane polyol in which the polyester polyols (A1) to (A3) are subjected to urethane elongation by reacting with a diisocyanate compound to give a number average molecular weight of 1,000 to 15,000.
• the urethane-elongated polyester polyol contains molecular weight components above a certain level and urethane bonds, making it possible to make a coating agent with excellent gas barrier properties.
• the isocyanate compound (B) may be any known compound having a plurality of isocyanate groups, without any particular limitation.
• examples of such isocyanate compound (B) include polyisocyanates having an aromatic structure in the molecular structure, such as tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and xylylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates have been modified with carbodiimide;
• Polyisocyanates with alicyclic structures in their molecular structure such as isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane;
• Straight-chain aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, lysine diisocyanate, and trimethylhexamethylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates have been modified with carbodiimide;
• isocyanurates of these polyisocyanates include isocyanurates of these polyisocyanates; allophanates of these polyisocyanates; biuret forms of these polyisocyanates; adducts of these polyisocyanates modified with trimethylolpropane; and polyurethane polyisocyanates, which are reaction products of these polyisocyanates and polyols.
• polyurethane polyisocyanate as the isocyanate compound (B), from the viewpoint of the balance between the cohesive strength and flexibility of the coating agent film, it is preferable to use one obtained by reacting the above-mentioned polyisocyanate with a polyol in a ratio in which the equivalent ratio of isocyanate groups to hydroxyl groups [NCO]/[OH] is 1.5 to 5.0.
• the polyols used in the synthesis of polyurethane polyisocyanate can be the polyhydric alcohols exemplified as raw materials for polyester polyol (A), polyester polyols, polyether polyols, etc.
• an isocyanate having an aromatic ring or a derivative thereof (isocyanurate, allophanate, biuret, adduct, polyurethane polyisocyanate) (B1) as the isocyanate compound (B).
• Specific examples of the isocyanate compound (B1) include xylylene diisocyanate, hydrogenated xylylene diisocyanate, toluene diisocyanate, and isocyanate compounds having a skeleton derived from diphenylmethane diisocyanate.
• the isocyanate compound (B) is a polyurethane polyisocyanate (B2) obtained by reacting at least one selected from polyester polyols (A1), (A2), and (A3) with an isocyanate having an aromatic ring or a derivative thereof (B1) in a ratio in which the equivalent ratio of isocyanate groups to hydroxyl groups [NCO]/[OH] is 1.5 to 5.0.
• the coating agent used in the present invention contains an organic solvent (C) capable of diluting (dissolving) the polyester polyol (A).
• organic solvent (C) include esters such as ethyl acetate, butyl acetate, and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide, and dimethyl sulfamide.
• the organic solvent used as a reaction medium during the production of the components of the polyol composition (I) or polyisocyanate composition (II) may also be used as a diluent during coating. It is preferable to use at least one of esters and ketones.
• the drying aid (D) has a function of promoting the volatilization of the organic solvent (C).
• the drying aid (D) include isosorbide, isomannide, isoidide, triacetin, and the like. It is preferable to use isosorbide.
• the organic solvent tends to be difficult to volatilize from a composition containing a polyester polyol and an organic solvent, but the coating agent using the above-mentioned polyester polyols (A1) to (A3) in particular can form a coating film with excellent gas barrier properties, but tends to easily hinder the volatilization of the organic solvent due to its excellent gas barrier properties.
• the organic solvent (C) becomes easy to volatilize in the drying process, the gas barrier coating agent has excellent drying properties, and the organic solvent (C) is unlikely to remain in the cured coating film.
• the drying aid (D) has a hydroxyl group. This allows it to react with the isocyanate compound (B) and be incorporated into the cured coating film, and unlike additives that do not have functional groups, there is no risk of it migrating from the gas barrier coating layer to other layers over time, and it has little effect on the physical properties of the gas barrier coating layer over time.
• the drying process referred to here refers to the process of mixing the polyol composition (I) and the polyisocyanate composition (II), applying it to a substrate, and then passing it through an oven to volatilize the organic solvent (C) contained in the coating film of the gas barrier coating agent.
• the hydroxyl group of the drying aid (D) is preferably a secondary hydroxyl group. Since it has a lower reactivity with the isocyanate compound (B) than a primary hydroxyl group, it is possible to effectively prevent the hydroxyl group from reacting with the isocyanate compound (B) before the drying step.
• the amount of the drying aid (D) is preferably 0.5% by mass or more, and more preferably 1% by mass or more, of the total solid content of the gas barrier coating agent. From the viewpoint of the blocking resistance of the gas barrier coating agent, it is preferably 30% by mass or less, and more preferably 10% by mass or less.
• the coating agent used in the present invention may contain components other than the above-mentioned components. These components may be contained in either or both of the polyol composition (I) and the polyisocyanate composition (II), or may be prepared separately from these and mixed immediately before application of the coating agent. Each component will be described below.
• the polyol composition (I) may contain a polyol (E) other than the polyester polyol (A).
• a polyol (E) other than the polyester polyol (A).
• the polyol (E) include polyester polyols, polyester polyether polyols, polyester polyurethane polyols, polyether polyols, polyether polyurethane polyols, polyurethane polyols, polycarbonate polyols, and polyhydric alcohols exemplified as raw materials for the polyester polyol (A).
• the same ones as those exemplified as the raw material for the polyester polyol (A) can be used.
• the isocyanate compound used in the synthesis of the polyol having a polyurethane skeleton the same ones as those exemplified as the isocyanate compound (B) can be used.
• polyether polyol there can be mentioned those obtained by ring-opening polymerization of polyoxyethylene glycol, polyoxypropylene glycol, and aliphatic polyol with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether.
• various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether.
• the amount of polyol (E) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or more, per 100 parts by mass of the total amount of polyester polyol (A) and polyol (E).
• the coating agent used in the present invention may contain an inorganic filler (F).
• inorganic fillers include silica, alumina, aluminum flakes, glass flakes, etc.
• a plate-like inorganic compound as the inorganic filler (F) since this improves gas barrier properties, light blocking properties, etc.
• plate-like inorganic compounds include hydrated silicates (phyllosilicate minerals, etc.), kaolinite-serpentine clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc (pyrophyllite, talc, keroli, etc.), smectite clay minerals (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, etc.), vermiculite clay minerals (vermiculite, etc.), mica or mica clay minerals (muscovite, phlogopite, etc., mica, margarite, tetrasilylic mica, taeniolite, etc.), chlorite (cookiteite, sudoite, clinochlore, chamosite, nimite, etc.), hydrotal
• the plate-like inorganic compound may be ionic, which has an electric charge between layers, or nonionic, which has no electric charge.
• the presence or absence of an electric charge between layers does not have a direct significant effect on the gas barrier properties of the coating layer.
• ionic plate-like inorganic compounds and inorganic compounds that swell in water are less dispersible in solvent-based coating agents, and increasing the amount added may cause the coating agent to thicken or become thixotropic, reducing suitability for application. For this reason, it is preferable for the plate-like inorganic compound to be nonionic, which has no electric charge between layers.
• the average particle size of the plate-like inorganic compound is not particularly limited, but is preferably 0.1 ⁇ m or more, and more preferably 1 ⁇ m or more, as an example. If it is smaller than 0.1 ⁇ m, the detour path for oxygen molecules will not be long, and sufficient improvement in gas barrier properties cannot be expected. There is no particular upper limit to the average particle size, but if the particle size is too large, defects such as streaks may occur on the coated surface depending on the coating method. For this reason, as an example, the average particle size is preferably 100 ⁇ m or less, and more preferably 20 ⁇ m or less. In this specification, the average particle size of the plate-like inorganic compound refers to the particle size that appears most frequently when the particle size distribution of the plate-like inorganic compound is measured using a light scattering measuring device.
• the aspect ratio of the plate-like inorganic compound is preferably high in order to improve the gas barrier properties due to the oxygen labyrinth effect. Specifically, it is preferably 3 or more, more preferably 10 or more, and most preferably 40 or more.
• the upper limit of the aspect ratio is, for example, 500.
• the proportion of the inorganic filler (F) in the total solid content of the polyol composition (I) and the polyisocyanate composition (II) is preferably 0.001 to 50 mass%, and more preferably 0.01 to 40 mass%.
• the coating agent used in the present invention preferably contains an anti-skinning agent (G).
• an organic solvent having a higher boiling point than the organic solvent (C) and having a high solubility for the polyester polyol (A) is used.
• the anti-skinning agent (G) it is possible to prevent the surface of the gas barrier coat layer from drying before the organic solvent (C) volatilizes from inside the coating film of the coating agent, thereby preventing the volatilization of the organic solvent (C).
• anti-skinning agents (G) include propylene glycol monomethyl ether, ethyl cellosolve, propyl acetate, butyl acetate, etc.
• the amount of the anti-skinning agent (G) is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the total amount of the polyol composition (I) and the polyisocyanate composition (II) excluding the anti-skinning agent (G) (including volatile components such as the organic solvent (C)).
• the coating agent used in the present invention can accelerate the curing reaction by using a catalyst (H) as necessary.
• the catalyst (H) is not particularly limited as long as it accelerates the urethane reaction of the polyol composition (I) and the polyisocyanate composition (II), and examples of the catalyst (H) include metal catalysts, amine catalysts, aliphatic cyclic amide compounds, and titanium chelate complexes.
• the metal catalyst examples include metal complex, inorganic metal, and organic metal catalysts.
• the metal complex catalyst include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate. From the viewpoint of toxicity and catalytic activity, iron acetylacetonate (Fe(acac) 3 ) or manganese acetylacetonate (Mn(acac) 2 ) is preferred.
• Inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, etc.
• Organometallic catalysts include organic zinc compounds such as zinc octoate, zinc neodecanoate, and zinc naphthenate; organic tin compounds such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organic nickel compounds such as nickel octoate and nickel naphthenate; organic cobalt compounds such as cobalt octoate and cobalt naphthenate; organic bismuth compounds such as bismuth octoate, bismuth neodecanoate, and bismuth naphthenate; and titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutylt
• Amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxy
• Examples of aliphatic cyclic amide compounds include ⁇ -valerolactam, ⁇ -caprolactam, ⁇ -enantholactam, ⁇ -capryllactam, and ⁇ -propiolactam.
• ⁇ -caprolactam is more effective at promoting hardening.
• Titanium chelate complexes are compounds whose catalytic activity is enhanced by exposure to ultraviolet light, and titanium chelate complexes having an aliphatic or aromatic diketone as a ligand are preferred because of their excellent curing acceleration effect.
• titanium chelate complexes having an aliphatic or aromatic diketone as a ligand are preferred because of their excellent curing acceleration effect.
• those having an alcohol with 2 to 10 carbon atoms as a ligand in addition to an aromatic or aliphatic diketone are preferred because the effects of the present invention are more pronounced.
• the catalyst (H) can be used alone or in combination of two or more kinds.
• the amount of catalyst (H) is preferably 0.001 to 3 parts by mass, and more preferably 0.01 to 2 parts by mass, per 100 parts by mass of the total solid content of the polyol composition (I) and the polyisocyanate composition (II).
• the coating agent used in the present invention may contain a coupling agent (I).
• a coupling agent (H) examples include silane coupling agents, titanate coupling agents, aluminum coupling agents, and the like.
• Silane coupling agents include aminosilanes such as ⁇ -aminopropyltriethoxysilane, ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethyldimethoxysilane, and N-phenyl- ⁇ -aminopropyltrimethoxysilane; epoxysilanes such as ⁇ -(3,4-epoxycyclohexyl)ethyltrimethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, and ⁇ -glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris( ⁇ -methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and ⁇ -methacryloxyprop
• Titanate coupling agents include, for example, tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.
• aluminum-based coupling agents examples include acetoalkoxyaluminum diisopropylate.
• the coating agent used in the present invention may contain phosphoric acid (J).
• phosphoric acid (J) include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, polyoxyethylene alkyl ether phosphate, and the like.
• the amount of the phosphoric acid (J) is preferably 1 ppm or more and 200 ppm or less of the total solid content of the coating agent.
• the coating agent used in the present invention may contain leveling agents, polymethyl methacrylate-based organic fine particles, defoamers, sagging prevention agents, wetting and dispersing agents, viscosity regulators, ultraviolet absorbers, metal deactivators, peroxide decomposers, flame retardants, reinforcing agents, plasticizers, lubricants, surface conditioners, rust inhibitors, fluorescent brightening agents, inorganic heat ray absorbers, flame retardants, antistatic agents, dehydrating agents, known and commonly used thermoplastic elastomers, tackifiers, melamine resins, reactive elastomers, etc.
• the amounts of these additives added are appropriately adjusted within a range that does not impair the desired properties of the coating agent used in the present invention.
• the polyol composition (I) and the polyisocyanate composition (II) are preferably used after adjusting the molar ratio ([NCO]/[OH]) of the isocyanate group contained in the polyisocyanate composition (II) to the hydroxyl group contained in the polyol composition (I) to be 0.3 to 6.
• the laminate of the present invention is obtained by applying the above-mentioned coating agent to a paper substrate and drying it to form a gas barrier coat layer.
• any known paper base material can be used without any particular limitation.
• the paper is produced by a known papermaking machine using natural fibers for papermaking such as wood pulp, but the papermaking conditions are not particularly specified.
• natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal hemp pulp, and flax pulp, and pulp obtained by chemically modifying these pulps.
• pulp chemical pulp by sulfate cooking method, acidic/neutral/alkaline sulfite cooking method, soda salt cooking method, ground pulp, chemi-ground pulp, thermomechanical pulp, etc.
• various commercially available high-quality papers, coated papers, backing papers, impregnated papers, cardboards, paperboards, etc. can also be used.
• Metal-deposited papers in which a metal oxide layer such as silica or alumina is deposited on these papers can also be used as the base material.
• the type and thickness of the paper base material can be selected according to the purpose. For example, for burger wraps, about 20 grams/ m2 per square meter is preferred, for paper cups, 200 to 300 grams/ m2 per square meter is preferred, and for paper plates, paper spoons, paper stirrers, etc., 50 to 500 grams/ m2 per square meter is preferred.
• the laminate of the present invention may be a laminate including a paper substrate, a heat seal layer which is a dried coating of a heat seal agent, and the gas barrier coat layer.
• the heat seal agent is applied and dried to form the heat seal layer.
• the heat seal agent used to form the heat seal agent is not particularly limited, and may be in any form, such as a type in which a thermoplastic resin having heat sealability is dissolved in an organic solvent, a type in which the thermoplastic resin is dissolved in water or an aqueous organic solvent, or an emulsion type in which the thermoplastic resin is dispersed in water or an aqueous organic solvent.
• the laminate of the present invention may also be a laminate including a paper substrate, a cold seal layer which is a dried coating of a cold sealant, and the gas barrier coat layer.
• the cold seal layer is formed by applying and drying the cold sealant.
• the cold sealant used to form the cold sealant may be in any form, such as a type in which a thermoplastic resin having cold sealability is dissolved in an organic solvent, a type in which it is dissolved in water or an aqueous organic solvent, or an emulsion type in which it is dispersed in water or an aqueous organic solvent.
• the laminate of the present invention may be a laminate including a paper base material, a heat seal film, the gas barrier coating layer disposed on the surface of the paper base material facing the heat seal film, and an adhesive layer disposed between the gas barrier coating layer and the heat seal film.
• the heat seal film is not particularly limited, and a general-purpose olefin-based heat seal film may be used. Specifically, a heat seal film made of an olefin resin and having heat sealability that melts and fuses with each other by heat is preferred.
• a film made of an olefin resin such as polyethylene, such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, or linear (linear) low-density polyethylene, polypropylene, an ethylene-propylene copolymer, or polymethylpentene may be used.
• the heat seal layer may be surface-treated in the same manner as the stretched polyolefin film.
• the thickness of the heat seal layer is preferably 15 ⁇ m or more and 500 ⁇ m or less, more preferably 20 ⁇ m or more and 250 ⁇ m or less, and even more preferably 30 ⁇ m or more and 100 ⁇ m or less. This makes it possible to improve the processability and puncture resistance of the laminate of the present invention while maintaining the heat sealability of the heat sealable resin layer.
• the laminate of the present invention may further include other substrates and layers in addition to the above-mentioned configuration.
• the laminate of the present invention from the viewpoint of sustainability, it is preferable to adopt a configuration taking into consideration its purpose, recycling method, etc.
• the laminate of the present invention may have a printed layer.
• the printed layer may be a printed layer directly printed on the paper substrate, or when a film layer described later is provided, the printed layer may be provided on the film layer.
• the printed layer is formed by a general printing method that has been used for printing on polymer films and paper using various printing inks such as liquid ink (gravure ink, flexo ink), offset ink, stencil ink, and inkjet ink. Biomass-certified inks are also preferably used.
• the printing layer used in the present invention may be a single layer or may have multiple printing layers. When there are multiple printing layers, the liquid printing ink used for each printing layer may be the same, may have the same composition but with different colorants, or may have different compositions.
• the laminate of the present invention does not require a filler because the coating agent used uses an organic solvent, but depending on the type of paper substrate, a filler layer made of a filler may be provided.
• the filler is not particularly limited, and examples of the filler that can be used include organic solvent solutions of polymers such as (meth)acrylic, styrene-butadiene, vinyl acetate, and chlorinated polyolefin, emulsions of polymers such as (meth)acrylic, vinyl acetate, and vinylidene chloride, and latexes such as SBR and NBR, which can be applied as coating agents.
• the laminate of the present invention may be provided with a water vapor barrier layer for the purpose of imparting water vapor barrier properties in addition to gas barrier properties.
• Methods for imparting water vapor barrier properties include a method of laminating a film having barrier properties and a method of forming a coating layer by applying a barrier coating agent, and the method of forming a coating layer by applying a barrier coating agent is simple and preferable.
• water vapor barrier coating agents include coating agents containing polymers such as polyvinylidene chloride (PVDC), or inorganic fine particles, such as silica, alumina, aluminum flakes, glass flakes, hydrated silicates (phyllosilicate minerals, etc.), kaolinite-serpentine clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc (pyrophyllite, talc, keroli, etc.), smectite clay minerals, etc.
• PVDC polyvinylidene chloride
• inorganic fine particles such as silica, alumina, aluminum flakes, glass flakes, hydrated silicates (phyllosilicate minerals, etc.), kaolinite-serpentine clay minerals (halloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite
• Coating agents containing clay minerals (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, etc.), vermiculite group clay minerals (vermiculite, etc.), mica or mica group clay minerals (muscovite, phlogopite, etc.
• barrier coating agents include those containing talc having an average particle size of 5 ⁇ m or more and an aspect ratio of 10 or more in synthetic adhesives such as styrene-butadiene, styrene-acrylic, ethylene-vinyl acetate, butadiene-methyl methacrylate, and vinyl acetate-butyl acrylate copolymers, maleic anhydride copolymers, and acrylic acid-methyl methacrylate copolymers (described in JP 2013-256013 A), and aqueous coating agents containing paraffin wax emulsions having 20 to
• barrier coating agents can be used without any particular limitations.
• Known barrier coating agents include the “SunBar” series manufactured by Sun Chemical Co., Ltd., the “HYDBAR” series manufactured by DIC Corporation, and polyester barrier coating agents described in Patent No. 5617831.
• barrier layer a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride may be used.
• a metal such as aluminum or a metal oxide such as silica or alumina
• a barrier film such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride
• the laminate of the present invention may contain functionality-imparting materials, such as scratch resistance-imparting materials, oil resistance-imparting materials, water resistance-imparting materials, heat resistance-imparting materials, or food contact materials, as part of the laminate's configuration.
• functionality-imparting materials may be commercially available products, and are often sold in the form of coating agents. Coating agents sold as such can impart these functions simply by coating the outermost layer of the laminate of the present invention, for example. (Hereinafter, such functionality-imparting coating agents may be referred to as functional coat agents.)
• a film may be laminated on the laminate of the present invention depending on the application.
• the film for food packaging include polyester films such as polyethylene terephthalate (PET) film and polybutylene succinate (PBS) film, polystyrene films, polyamide films, polyacrylonitrile films, polyethylene films (LLDPE: low density polyethylene film, HDPE: high density polyethylene film, MDOPE: uniaxially oriented polyethylene film, BOPE: biaxially oriented polyethylene film), polypropylene films (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), cellulose-based films such as cellophane, polyolefin films such as gas barrier heat seal films in which an olefin-based heat sealable resin layer is provided on one or both sides of a resin having gas barrier properties such as an ethylene-vinyl alcohol copolymer or polyvinyl alcohol, polyvinyl alcohol film, and ethylene-vinyl alcohol cop
• a film having aroma-retaining properties as the substrate.
• films include a film made of a resin having aroma-retaining properties, a film made of a polymer alloy of a resin having aroma-retaining properties and an olefin resin, a film obtained by extrusion lamination or coextrusion lamination of a resin having aroma-retaining properties and another resin, a film obtained by coating a resin having aroma-retaining properties on a film made of another resin, and a film having a vapor-deposited layer of a metal or metal oxide, which will be described later.
• resins having aroma-retaining properties include polyester, cyclic polyolefin, polyvinylidene chloride, ethylene vinyl alcohol copolymer, and the like.
• the film having aroma-retaining properties may have heat-sealing properties.
• Methods for imparting heat-sealing properties to a film having aroma-retaining properties include, for example, a method of extrusion lamination or coextrusion lamination of a resin having aroma-retaining properties and a resin having heat-sealing properties, and a method of coating a resin having aroma-retaining properties on a resin having heat-sealing properties.
• aroma-retaining films examples of which include the Non-Catch series manufactured by Kyodo Printing Co., Ltd., the Olyester series manufactured by Toyobo Co., Ltd., Senesi KOP manufactured by Daicel Corporation, and the DIFAREN MP series manufactured by DIC Corporation.
• Biomass films are sold by various companies, and for example, sheets such as those listed in the list of biomass certified products listed by the Japan Organics Resources Association can be used.
• biomass films include those that use biomass-derived ethylene glycol as a raw material.
• Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass as a raw material.
• biomass-derived ethylene glycol can be obtained by a conventionally known method of producing ethylene glycol via ethylene oxide from biomass ethanol.
• Commercially available biomass ethylene glycol may also be used; for example, biomass ethylene glycol available from India Glycoal Limited can be suitably used.
• films containing biomass polyester, biomass polyethylene terephthalate, etc. in which biomass-derived ethylene glycol is used as the diol unit and fossil fuel-derived dicarboxylic acid is used as the dicarboxylic acid unit, are known.
• the dicarboxylic acid unit of the biomass polyester uses a dicarboxylic acid derived from a fossil fuel.
• a dicarboxylic acid an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and a derivative thereof can be used without limitation.
• the copolymer polyester may be a copolymer polyester containing a copolymer component as a third component, such as a bifunctional oxycarboxylic acid or at least one polyfunctional compound selected from the group consisting of a trifunctional or higher functional polyhydric alcohol, a trifunctional or higher functional polycarboxylic acid and/or anhydride thereof, and a trifunctional or higher functional oxycarboxylic acid, in order to form a crosslinked structure.
• a copolymer component as a third component, such as a bifunctional oxycarboxylic acid or at least one polyfunctional compound selected from the group consisting of a trifunctional or higher functional polyhydric alcohol, a trifunctional or higher functional polycarboxylic acid and/or anhydride thereof, and a trifunctional or higher functional oxycarboxylic acid, in order to form a crosslinked structure.
• biomass polyolefin films such as biomass polyethylene films containing polyethylene resins made from biomass-derived ethylene glycol and biomass polyethylene-polypropylene films are also known.
• the polyethylene-based resin is not particularly limited except that ethylene glycol derived from biomass is used as a part of the raw material.
• examples of the polyethylene-based resin include a homopolymer of ethylene and a copolymer of ethylene and an ⁇ -olefin containing ethylene as a main component (ethylene- ⁇ -olefin copolymer containing 90% by mass or more of ethylene units). These may be used alone or in combination of two or more.
• the ⁇ -olefin constituting the copolymer of ethylene and ⁇ -olefin is not particularly limited, and examples thereof include ⁇ -olefins having 4 to 8 carbon atoms, such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.
• Known polyethylene resins such as low-density polyethylene resins, medium-density polyethylene resins, and linear low-density polyethylene resins, can be used.
• linear low-density polyethylene resins (LLDPE) (copolymers of ethylene and 1-hexene, or copolymers of ethylene and 1-octene) are preferred, and linear low-density polyethylene resins having a density of 0.910 to 0.925 g/cm 3 are more preferred.
• Biomass films that use biomass raw materials and are classified according to the biomass plastic degree specified by ISO 16620 or ASTM D6866 are also on the market.
• Radioactive carbon-14C exists in the atmosphere at a ratio of 1 in 1012 particles, and this ratio is the same for atmospheric carbon dioxide, so this ratio remains the same even in plants that fix this carbon dioxide through photosynthesis.
• the carbon in plant-derived resins contains radioactive carbon-14C.
• the carbon in fossil fuel-derived resins contains almost no radioactive carbon-14C. Therefore, by measuring the concentration of radioactive carbon-14C in the resin with an accelerator mass spectrometer, the proportion of plant-derived resin in the resin, i.e., the biomass plastic degree, can be determined.
• plant-derived low-density polyethylene which is a biomass plastic with a biomass plastic content of 80% or more, preferably 90% or more as specified by ISO16620 or ASTM D6866
• plant-derived low-density polyethylene examples include Braskem's product names "SBC818”, “SPB608”, “SBF0323HC”, “STN7006”, “SEB853”, and “SPB681”, and films using these as raw materials can be suitably used.
• films and sheets containing starch, a biomass raw material, and polylactic acid are also known. These can be selected and used as appropriate depending on the application.
• the biomass film may be a laminate of multiple biomass films, or a laminate of a conventional petroleum-based film and a biomass film. These biomass films may be unstretched or stretched films, and there are no limitations on the manufacturing method.
• an olefin-based film which is a so-called mono-material material, may be appropriately selected from the above films.
• These films may also have a printed layer.
• the printed layer is formed by a general printing method that has been used for printing on polymer films and paper using various printing inks such as liquid ink (gravure ink, flexo ink), offset ink, stencil ink, and inkjet ink. Biomass-certified inks are also preferably used.
• the printing layer used in the present invention may be a single layer or may have multiple printing layers. When there are multiple printing layers, the liquid printing ink used for each printing layer may be the same, may have the same composition but with different colorants, or may have different compositions.
• the film may be one that has been stretched.
• a typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-making method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching.
• sequential biaxial stretching it is common to first perform longitudinal stretching, and then transverse stretching. Specifically, a method that combines longitudinal stretching using the speed difference between rolls and transverse stretching using a tenter is often used.
• the film surface may be subjected to various surface treatments such as flame treatment or corona discharge treatment to ensure that the coating is free of defects such as film breaks or repellency.
• a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film containing a gas barrier layer of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, vinylidene chloride, etc. may be used in combination.
• a laminate with barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc. can be obtained.
• the above film may be attached to the laminate of the paper substrate of the present invention using an adhesive described below, or may be laminated onto the laminate of the paper substrate of the present invention using a method such as co-extrusion.
• the adhesive used when bonding the laminate of the paper substrate of the present invention to another substrate may be a publicly known urethane-based two-component curing adhesive, one-component curing adhesive, hot melt adhesive, etc.
• a gas barrier coating layer between the substrate and the adhesive layer.
• the adhesive has excellent gas barrier properties, it is preferable because the gas barrier properties of the laminate can be further improved.
• Commercially available adhesives with excellent gas barrier properties include the PASLIM series manufactured by DIC Corporation and Maxive manufactured by Mitsubishi Gas Chemical Company, Inc.
• a two-component curing adhesive containing at least one of the polyester polyols (A1) to (A3) used in the coating agent used in the present invention and a polyisocyanate compound can also be suitably used as a gas barrier adhesive.
• the laminate of the present invention may have an overcoat layer.
• the overcoat layer is provided on the printed layer for the purpose of protecting the printed layer, and is obtained by applying and drying an overcoat agent.
• a conventionally known overcoat agent can be suitably used to form the overcoat layer.
• the laminate of the present invention may have a vapor-deposited layer.
• the vapor-deposited layer include vapor-deposited layers containing metals such as aluminum, and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. From the viewpoint of oxygen barrier properties and water vapor barrier properties, an aluminum vapor-deposited layer is preferred.
• the vapor-deposited layer may be provided on these layers, or a film or paper already provided with a vapor-deposited layer may be used.
• the deposition layer can be formed by a conventional method, for example, physical vapor deposition methods (PVD method) such as vacuum deposition, sputtering, and ion plating, chemical vapor deposition methods (CVD method) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.
• PVD method physical vapor deposition methods
• CVD method chemical vapor deposition methods
• the thickness of the vapor deposition film is preferably 1 nm or more and 100 nm or less, more preferably 15 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.
• the thickness is preferably 1 nm or more and 140 nm or less, more preferably 5 nm or more and 30 nm or less, and even more preferably 5 nm or more and 20 nm or less.
• a composite film consisting of two or more layers of vapor-deposited films of different inorganic oxides can be formed and used by combining both physical vapor deposition and chemical vapor deposition.
• the degree of vacuum in the vapor deposition chamber is preferably about 10 -2 to 10 -8 mbar before oxygen is introduced, and is preferably about 10 -1 to 10 -6 mbar after oxygen is introduced.
• the amount of oxygen introduced varies depending on the size of the vapor deposition machine.
• an inert gas such as argon gas, helium gas, or nitrogen gas may be used as a carrier gas to the extent that no problems occur.
• the film transport speed is preferably about 10 to 800 m/min, particularly about 50 to 600 m/min.
• Examples of specific embodiments of the laminate of the present invention include the following structures, but the present invention is not limited thereto.
• “/” indicates that the layers are adjacent
• “sealing layer” is an expression that includes all layers that exhibit sealing properties, such as a heat seal film layer, a coating layer of a heat sealant, and a coating layer of a cold sealant.
• Printing layer/paper/gas barrier coating layer Printing layer/paper/gas barrier coating layer Printing layer/paper/gas barrier coating layer/water vapor barrier coating layer Printing layer/paper/water vapor barrier coating layer Printing layer/paper/water vapor barrier coating layer Printing layer/paper/filling layer/gas barrier coating layer Printing layer/paper/filling layer/water vapor barrier coating layer Printing layer/paper/filling layer/water vapor barrier coating layer/gas barrier coating layer Filling layer/paper/water vapor barrier coating layer Printing layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer Printing layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer Printing layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer Printing layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer Printing layer/gas barrier coating layer/filling layer/paper/filling layer/water vapor barrier coating layer Water vapor barrier coating layer/printing layer/paper/gas barrier coating layer Water vapor barrier
• Gas barrier coating layer Filling layer/Paper/Water vapor barrier coating layer/Sealing layer Gas barrier coating layer/Paper/Filling layer/Water vapor barrier coating layer/Sealing layer Gas barrier coating layer Filling layer/Paper/Filling layer/Water vapor barrier coating layer/Sealing layer Sealing layer/Paper/Gas barrier coating layer Sealing layer/Paper/Gas barrier coating layer Sealing layer/Paper/Water vapor barrier coating layer Sealing layer/Paper/Water vapor barrier coating layer Sealing layer/Paper/Filling layer/Gas barrier coating layer Sealing layer/Paper/Filling layer/Gas barrier coating layer Sealing layer/Paper/Filling layer/Gas barrier coating layer Sealing layer/Paper/Filling layer/Water vapor barrier coating layer Sealing layer/Paper/Filling layer/Water vapor barrier coating layer Sealing layer/Paper/Filling layer/Water vapor barrier coating layer Sealing layer/Paper/Filling layer/Water vapor barrier coating layer Sealing layer/Paper/Filling
• Printing layer/paper/gas barrier coating layer/sealing layer Printing layer/paper/gas barrier coating layer/water vapor barrier coating layer/sealing layer Printing layer/paper/water vapor barrier coating layer/gas barrier coating layer/sealing layer Printing layer/paper/water vapor barrier coating layer/sealing layer Printing layer/paper/filling layer/gas barrier coating layer/sealing layer Printing layer/paper/filling layer/gas barrier coating layer/water vapor barrier coating layer/sealing layer Printing layer/paper/filling layer/water vapor barrier coating layer/gas ...gas barrier coating layer Filling layer/paper/water vapor Barrier coat layer/sealing layer Printed layer/gas barrier coat layer/paper/filling layer/water vapor barrier coat layer/sealing layer Printed layer/gas barrier coat layer Filling layer/paper/filling layer/water vapor barrier coat layer/sealing layer Water vapor barrier coat layer/printing layer/paper/gas barrier coat layer/sealing layer Water vapor barrier coat
• Examples include functional coating layer/paper/gas barrier coating layer/functional coating layerfunctional coating layer/paper/water vapor barrier coating layer/gas barrier coating layer/functional coating layerfunctional coating layer/gas barrier coating layer/paper/water vapor barrier coating layerfunctional coating layer/paper/filling layer/gas barrier coating layer/functional coating layerfunctional coating layer/paper/filling layer/gas barrier coating layer/functional coating layerfunctional coating layer/paper/filling layer/gas barrier coating layer/water vapor barrier coating layer/coating layer, etc.
• a printed layer may also be included between these layers.
• Examples include functional coating layer/paper/filling layer/gas barrier coating layer/sealing layerfunctional coating layer/gas barrier coating layer/filling layer/paper/water vapor barrier coating layer/sealing layerfunctional coating layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer/sealing layerfunctional coating layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer/sealing layerfunctional coating layer/gas barrier coating layer/paper/filling layer/water vapor barrier coating layer/sealing layerfunctional coating layer/gas barrier coating layerfilling layer/paper/filling layer/water vapor barrier coating layer/sealing layersealing layer/gas barrier coating layer/filling layer/paper/water vapor barrier coating layer, etc.
• a printed layer may also be included between these layers.
• the heat seal layer with aroma retention can be a film in which heat sealability has been imparted to a film with aroma retention.
• Commercially available films with aroma retention include the Non-Catch series manufactured by Kyodo Printing Co., Ltd., the Olyester series manufactured by Toyobo Co., Ltd., Senesi KOP manufactured by Daicel Corporation, and the DIFAREN MP series manufactured by DIC Corporation.
• the "functional coating layer” may be replaced with an “extruded film layer” or a “film layer/adhesive layer.”
• a printing layer is disposed either on the surface of the gas barrier coating layer opposite the front substrate, or between the gas barrier coating layer and the front substrate.
• the deposition layer of the front substrate may be located on either the gas barrier coating layer side or the heat seal layer side, but from the viewpoint of gas barrier properties, it is preferably located on the gas barrier coating layer side.
• the laminate of the present invention can be suitably used for various applications, such as packaging materials for food, medicines, and daily necessities; paper tableware such as lid materials, paper straws, paper napkins, paper spoons, paper plates, and paper cups; wall materials, roofing materials, solar cell panel materials, packaging materials for batteries, window materials, outdoor flooring materials, lighting protection materials, automotive parts, signs, stickers, and other outdoor industrial applications; decorative sheets used in simultaneous injection molding decoration methods, and packaging materials for liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, and the like.
• the laminate of the present invention can be used as a multi-layer packaging material for protecting foods, medicines, etc.
• the layer structure can be changed depending on the contents, the environment of use, and the form of use.
• the package of the present invention may be appropriately provided with an easy-opening treatment or a resealable means.
• the packaging material of the present invention is obtained by using the laminate of the present invention, overlapping the surfaces of the sealant film or heat seal layer of the laminate so that they face each other, and then heat sealing the peripheral edge to form a bag.
• the bag-making method include folding or overlapping the laminate of the present invention so that the surfaces of the inner layers (the surfaces of the sealant film) face each other, and heat sealing the peripheral edge, for example, by using a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a grooving seal type, a pleated seal type, a flat bottom seal type, a square bottom seal type, a gusset type, or other heat seal type.
• the packaging material of the present invention can take various forms depending on the contents, the environment in which it is used, and the form in which it is used. Self-supporting packaging materials (standing pouches) are also possible. Heat sealing can be performed by known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high frequency seal, and ultrasonic seal.
• the packaging material of the present invention is filled with the contents through its opening, and the opening is then heat-sealed to produce a product using the packaging material of the present invention.
• contents that can be filled include food products such as rice crackers, bean snacks, nuts, biscuits and cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candies, and snack foods; staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, porridge, packaged rice cakes, and cereal foods; pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potatoes; and livestock products such as ham, bacon, sausages, processed chicken, and corned beef.
• fish ham and sausages fish paste products, fish products such as kamaboko, nori seaweed, tsukudani (food boiled in soy sauce), dried bonito flakes, shiokara (salted fish), smoked salmon, and spicy cod roe; fruit pulp such as peaches, mandarin oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; pre-cooked foods such as frozen and chilled prepared foods, including hamburger steaks, meatballs, seafood fries, gyoza dumplings, and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; and pet food.
• fish paste products fish products such as kamaboko, nori seaweed, tsukudani (food boiled in soy sauce), dried bonito flakes, shiokara (salted fish), smoked salmon, and spicy cod roe
• fruit pulp such as peaches, mandarin orange
• non-food items including tobacco, disposable hand warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and milky lotion, vacuum insulation materials, batteries, etc.
• polyester polyol (A)> Synthesis of polyester polyol (A-1) 1.30 parts of ethylene glycol, 27.00 parts of glycerin, and 42.00 parts of phthalic anhydride were charged into a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the internal temperature was maintained at 190°C by gradually heating so that the temperature at the top of the rectification tube did not exceed 100°C.
• the acid value reached 40 mgKOH/g 6.00 parts of phthalic anhydride were added, and when the acid value reached 70 mgKOH/g, the esterification reaction was terminated.
• a polyester polyol (A-1) with a number average molecular weight of 890 was obtained. The hydroxyl value was 169 mgKOH/g.
• polyester polyol (A-2) 5.00 parts of ethylene glycol, 62.00 parts of tris(2-hydroxyethyl)isocyanuric acid, and 35.00 parts of phthalic anhydride were charged into a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the inside temperature was maintained at 220°C by gradually heating so that the temperature at the top of the rectification tube did not exceed 100°C.
• the acid value reached 3 mgKOH/g
• the esterification reaction was terminated to obtain polyester polyol (A-2) having a number average molecular weight of 1100.
• the hydroxyl value was 221 mgKOH/g.
• Solvent-based gas barrier coating agents of the Examples and Comparative Examples were prepared with the formulations shown in Table 1.
• the XDI-TMP adduct is a trimethylolpropane adduct of xylylene diisocyanate
• the kaolin is BARRISURF HX (manufactured by IMERYS, kaolin/non-swelling, interlayer nonionic, plate-like, average particle size/1.5 ⁇ m, aspect ratio/approximately 100). Blanks indicate no formulation.
• Paper base material 1 Pure white roll paper manufactured by Nippon Paper Industries Co., Ltd., basis weight 40 g/ m2
• Paper base material 2 white glassine paper, basis weight 40 g/ m2 , manufactured by Nippon Paper Industries Co., Ltd.
• Laminates of the examples and comparative examples were prepared with the layer configurations shown in Tables 2 to 4.
• the layer configuration of the laminate is represented as having a paper substrate at the center, with a printed layer and a water vapor barrier layer in this order on the surface side of the paper substrate (indicated by " ⁇ surface"), and a sealing layer, a gas barrier layer and a heat seal layer in this order on the back side of the paper substrate (indicated by " ⁇ back side”).
• the materials used to obtain each layer are listed in the columns for Examples 1 to 7 and Comparative Examples 1 to 6. "-" indicates that no layer is present.
• Each layer was formed as follows.
• Print layer GPW-5004 804 black (water-based ink for paper, manufactured by DIC Corporation) was printed using a gravure plate of Helio 175 lines/inch with a gravure coater to form a printed layer.
• the printed layer is formed on the surface of the paper base material 1
• the printed layer is formed on the gas barrier coating layer.
• Example 1 Water vapor barrier layer
• HYDBAR 99 water vapor barrier coating agent, manufactured by DIC Corporation
• SunBar BARV656 water vapor barrier coating agent, manufactured by Sun Chemical Co., Ltd.
• the applied amount of the water vapor barrier coating agent after drying was 4.0 g/ m2 .
• the water vapor barrier layer is formed on the surface of the print layer
• Example 6 the water vapor barrier layer is formed on the gas barrier coat layer.
• Example 1 (Sealing layer) DIC SEAL W-483 (DIC Corporation, water-based seal coating agent) was applied with a bar coater and dried in an oven at 80°C for 1 minute to form a seal layer.
• the coating amount of the seal coating agent after drying was 4.0 g/ m2 .
• the filling layer is formed on the back surface of the paper base material, and in Example 5, the filling layer is formed on the front surface of the paper base material.
• any of Coating Agents 1 to 3 listed in Table 1 or a commercially available polyvinyl alcohol resin-based water gas barrier coating agent (PVA-based water-based coating agent P1) was applied with a bar coater, dried in an oven at 80°C for 1 minute, and then cured at 40°C for 3 days to form a gas barrier coat layer.
• the coating amount of Coating Agents 1 to 3 after drying was 3.0 g/ m2 .
• the coating amount of water-based coating agent P1 was 1.0 g/ m2 .
• the gas barrier coating layer is formed on the filling layer, and in Example 7, the gas barrier coating layer is formed on the surface of the paper base material.
• Heat seal layer DIC Seal A-970NT (a heat seal agent manufactured by DIC Corporation) was applied with a bar coater and dried in an oven at 80°C for 1 minute to form a heat seal layer.
• the coating amount of the heat seal agent after drying was 5.0 g/ m2 .
• the heat seal layer is formed on the gas barrier coating layer, and in Example 5, the heat seal layer is formed on the back surface of the paper substrate.
• the laminate of the present invention exhibited good gas barrier properties even without a filling layer and under high humidity conditions.
• Comparative Example 2 in which an aqueous gas barrier coating agent was used, the barrier properties significantly deteriorated under high humidity.
• Comparative Example 3 in which an aqueous gas barrier coating agent was used without a filling layer, the gas barrier properties were extremely poor over the entire humidity range.

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• 2023
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