Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
• • 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
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
• • 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
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • 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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/80—Packaging reuse or recycling, e.g. of multilayer packaging

Definitions

• the present invention relates to a recyclable gas barrier laminate film, a packaging material, and a separation and recovery method.
• Gas barrier materials are used in various fields to prevent the intrusion of gases such as moisture and oxygen from the outside air.
• packaging materials used for packaging food and beverages are required to have oxygen barrier properties to prevent the intrusion of oxygen from the outside in order to suppress oxidation in order to protect the contents and preserve food for a long period of time, carbon dioxide barrier properties, and barrier properties against various aroma components.
• gas barrier laminated films using plastic films as base materials as an alternative to conventional glass substrates are being considered as sealing materials to protect the internal structure of solar cells and electronic devices and to block oxygen and water vapor from the outside in order to provide products that are thinner, lighter, or more flexible.
• Known methods for producing such gas barrier laminate films include coating a plastic film substrate with a coating agent containing polyvinyl alcohol, ethylene vinyl alcohol or the like (see Patent Documents 1 and 2).
• the objective of the present invention is to provide a recyclable laminated film with gas barrier properties and a packaging material using the same.
• gas barrier laminate film having a resin layer containing polyvinyl alcohol between an olefin resin film and a print layer or a surface coating layer has sufficient gas barrier film functionality, and can be easily separated into single layer films by ordinary alkali treatment.
• the present invention provides a gas barrier laminate film that has a resin layer containing a vinyl alcohol polymer between an olefin resin film and a print layer or a surface coating layer.
• the present invention also provides a packaging material using the gas barrier laminate film described above.
• the present invention also provides recycled plastics using the gas barrier laminate film described above.
• the present invention also provides a separation and recovery method that includes the steps of immersing the gas barrier laminate film described above in a stripping solution and recovering each layer that has been separated and detached.
• the present invention provides a gas barrier laminated film that fully functions as a gas barrier film and can be easily separated into single-layer films by a typical alkali treatment.
• the olefin resin film used in the present invention may be a film made of a thermoplastic resin mainly composed of an olefin resin.
• the olefin resin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear (linear) low-density polyethylene, polypropylene, ethylene-propylene copolymer, ⁇ -olefin polymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, cyclic olefin resin, ionomer resin, and polymethylpentene; and modified olefin resins obtained by modifying an olefin resin with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or
• 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-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass.
• biomass-derived ethylene glycol can be obtained by a conventional method of producing ethylene glycol from biomass ethanol via ethylene oxide.
• Commercially available biomass ethylene glycol may also be used; for example, biomass ethylene glycol available from India Glycoal Limited can be suitably used.
• Radioactive carbon-14C exists in the atmosphere at a ratio of 1 in 1012 particles, and this ratio does not change with atmospheric carbon dioxide, so this ratio does not change even in plants that fix this carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins contains radioactive carbon-14C. In contrast, 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.
• 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 an ethylene homopolymer 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), and these can 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 resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used.
• linear low density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferred, and linear low density polyethylene resin having a density of 0.910 to 0.925 g/cm3 is more preferred.
• the biomass film may be a laminate of multiple biomass films, or a laminate of a conventional petroleum-based film and a biomass film.
• the substrate may be one that has been subjected to some kind of surface treatment, such as a physical treatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, or flame treatment, or a chemical treatment such as oxidation treatment using chemicals, or other treatment.
• a physical treatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, or flame treatment
• a chemical treatment such as oxidation treatment using chemicals, or other treatment.
• the substrate can be manufactured by a conventionally known film-forming method such as extrusion, cast molding, T-die, cutting, or inflation from the above-mentioned resin. It may be an unstretched film, or may be one that has been stretched uniaxially or biaxially using a tenter method, tubular method, or the like from the viewpoint of the strength, dimensional stability, and heat resistance of the film (1).
• the substrate may contain additives as necessary.
• plastic compounding agents and additives such as elastomers, lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments can be added for the purpose of improving or modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mold resistance, electrical properties, strength, etc.
• the amount of additives added is adjusted within a range that does not affect other performance properties or recyclability.
• the thickness of the substrate is not particularly limited, and may be appropriately selected in the range of 0.1 to 300 ⁇ m from the viewpoint of moldability and transparency.
• the range is preferably 0.3 to 100 ⁇ m. If the thickness is less than 0.1 ⁇ m, the strength is insufficient, and if it exceeds 300 ⁇ m, the rigidity becomes too high, which may make processing difficult.
• the layer structure is as simple as possible, but from the viewpoint of distribution of the packaging material, printing is often necessary to indicate the contents of the packaging material and a description or name of the product.
• the above-mentioned base material is often printed as well.
• the printing layer is a layer on which characters, figures, symbols, and other desired patterns are printed.
• the printing method or printing ink there is no particular limitation on the printing method or printing ink, and any known printing method or printing ink can be used.
• Printing inks using gravure printing, flexographic printing, lithographic offset printing, inkjet recording printing, and the like are often used for the film used as the substrate.
• Printing inks that combine these printing methods with a method of curing with active energy rays such as ultraviolet rays (UV), LEDs, and electron beams (EB), or a method of curing with heat, etc. are also used.
• active energy rays such as ultraviolet rays (UV), LEDs, and electron beams (EB), or a method of curing with heat, etc.
• UV ultraviolet rays
• EB electron beams
• heat heat
• gravure printing ink and flexographic printing ink in some industries, gravure printing ink and flexographic printing ink are called liquid ink
• UV-curable ink for lithographic offset printing in some industries, gravure printing ink and flexographic printing ink are called liquid ink
• electron beam curable ink for lithographic offset printing UV-curable ink for inkjet recording and printing
• electron beam curable ink for inkjet recording and printing inkjet recording and printing.
• the position where the printed layer printed using these inks is provided is arbitrary, and it may be provided on the first substrate, or a substrate on which a separate printed layer is provided may be one of the components of the laminate of the present invention, and the position is arbitrary.
• the ink may contain a resin, a colorant, and a solvent as essential components, or it may be a so-called clear ink that contains a resin and a solvent but does not substantially contain a colorant. Below, we will explain the liquid inks that are most commonly used for printing on film.
• the resins used in the liquid ink are not particularly limited, and examples include acrylic resin, polyester resin, styrene resin, styrene-maleic acid resin, maleic acid resin, polyamide resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyvinyl chloride resin, chlorinated polypropylene resin, cellulose-based resin, epoxy resin, alkyd resin, rosin-based resin, rosin-modified maleic acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc., and one or more of these can be used in combination.
• at least one or two or more selected from polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin are used.
• Colorants used in liquid inks include inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite; organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments; and extender pigments such as calcium carbonate, kaolin clay, barium sulfate, aluminum hydroxide, and talc.
• inorganic pigments such as titanium oxide, red iron oxide, antimony red, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite
• organic pigments such as soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments
• Liquid inks for film printing are often organic solvent-based inks.
• the organic solvents used preferably do not contain aromatic hydrocarbon organic solvents. More specifically, examples of such organic solvents include alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, and butanol; ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester organic solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; aliphatic hydrocarbon organic solvents such as n-hexane, n-heptane, and n-octane; and alicyclic hydrocarbon organic solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, and cyclooctane. These can be used
• the surface coating layer is provided for the purpose of protecting the olefin resin film.
• a surface coating layer having heat resistance is preferable because it can suppress the occurrence of wrinkles caused by a heat seal bar used during processing in bag making, even if the olefin resin film is a resin with poor heat resistance such as a polyethylene resin.
• the surface coating layer can be provided by applying a coating agent (A) (hereinafter sometimes simply referred to as coating agent (A)).
• the heat-resistant coating agent (A) preferably contains, as a main component, a polymeric compound whose homopolymer glass transition temperature (hereinafter sometimes referred to as Tg) is 70° C. or higher, and preferably contains, for example, a compound having a cellulose skeleton, a benzene ring skeleton, an isocyanuric ring skeleton, or an alicyclic skeleton.
• Tg homopolymer glass transition temperature
• the resin composition include cellulose derivatives such as cellulose nitrate, cellulose acetate, cellulose propionate, and cellulose butyrate, polyester resins having a benzene ring such as phthalic acid, naphthalene dicarboxylic acid, and ethylene oxide (hereinafter sometimes referred to as EO) adducts of bisphenol A, and/or alicyclic skeletons such as cyclopentanediol and dimethyloltricyclodecane, and aromatic isocyanates such as diphenylmethane diisocyanate, toluene diisocyanate, xylene diisocyanate, and naphthalene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate and norbornene diisocyanate, and/or urethane resins in which isocyanuric triisocyanate is bonded to a polyol and/or tris(2-hydroxy)
• polyisocyanates using the above-mentioned isocyanates may be used as a curing agent.
• compounds having a benzene ring and an unsaturated double bond such as styrene and phenoxydiethylene glycol acrylate, and/or compounds having an alicyclic structure and an unsaturated double bond, such as isobornyl acrylate and dicyclopentanyl acrylate, and radical copolymers of (meth)acrylate, etc.
• a resin having a low Tg may be mixed and used.
• the total content of the cellulose skeleton, benzene ring skeleton, isocyanuric ring skeleton and alicyclic skeleton of the above-mentioned compound is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, based on the solid content of the heat-resistant coating layer (A).
• the Tg of the homopolymer is more preferably 80° C. or higher, and most preferably 100° C. or higher.
• the coating agent (A) may be colored.
• the colorant include inorganic pigments, organic pigments, and dyes used in general inks, paints, and recording agents, such as those used in the printing layer (E) described below. Among these, pigments are preferred.
• organic pigments include soluble azo-based, insoluble azo-based, azo-based, phthalocyanine-based, halogenated phthalocyanine-based, anthraquinone-based, anthanthrone-based, dianthraquinonyl-based, anthrapyrimidine-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine azo-based, flavanthrone-based, diketopyrrolopyrrole-based, isoindoline-based, indanthrone-based, and carbon black-based pigments.
• carmine 6B lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthalic yellow, chromophthalic red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. Both non-acid-treated and acid-treated pigments can be used.
• inorganic pigments examples include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, litbones, antimony white, and gypsum.
• white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, litbones, antimony white, and gypsum.
• titanium oxide is particularly preferred. Titanium oxide exhibits white color and is preferred from the viewpoints of coloring power, hiding power, chemical resistance, and weather resistance, and from the viewpoint of printing performance, the titanium oxide is preferably treated with silica and/or alumina.
• inorganic pigments other than white examples include aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, and zircon.
• Aluminum is in powder or paste form, but it is preferable to use it in paste form from the standpoint of handleability and safety. Whether leafing or non-leafing aluminum is used is appropriately selected from the standpoint of brightness and concentration.
• the coating agent (A) preferably uses inorganic fine particles such as alumina, magnesia, titania, zirconia, and silica (quartz, fumed silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica, etc.) as aggregates, because they have excellent heat resistance.
• inorganic fine particles such as alumina, magnesia, titania, zirconia, and silica (quartz, fumed silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica, etc.
• boron nitride, aluminum nitride, alumina oxide, titanium oxide, magnesium oxide, zinc oxide, silicon oxide, etc. are preferable because they have excellent thermal conductivity.
• the inorganic fine particles may be used alone or in combination of multiple types.
• the shape of the silica fine particles is not particularly limited, and spherical, hollow, porous, rod-like, plate-like, fibrous, or amorphous silica fine particles can be used.
• commercially available hollow silica fine particles include Silinax manufactured by Nittetsu Mining Co., Ltd.
• the primary particle diameter of the inorganic fine particles is preferably in the range of 5 to 200 nm. If the diameter is 5 nm or more, the inorganic fine particles in the dispersion are well dispersed, and if the diameter is within 200 nm, the strength of the cured product is good. More preferably, the diameter is 10 nm to 100 nm.
• the inorganic fine particles can be blended in a ratio of 5 to 90% by weight based on the total solid content of the coating agent (A) and the inorganic fine particles, and the blending amount may be appropriately changed depending on the purpose. In particular, the blending amount is preferably 20% by weight or more.
• Waxes, silicon additives, and organic beads can be used in the coating agent (A) to prevent damage to the coating film, to prevent blocking during laminate formation, and to provide workability during bag making after the laminate is created.
• waxes such as amide wax, polypropylene wax, polyethylene wax, paraffin wax, carnauba wax, and rice wax, ethylene oxide (EO) adducts of dimethylsiloxane, silicon additives of modified silicon, and organic beads made of acrylic, nylon, urethane, or epoxy can be added.
• the solvent used in the coating agent (A) is not particularly limited, but examples include aromatic hydrocarbon organic solvents such as water, toluene, xylene, Solvesso #100, Solvesso #150, etc., aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octane, decane, etc., and various ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc.
• aromatic hydrocarbon organic solvents such as water, toluene, xylene, Solvesso #100, Solvesso #150, etc.
• aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octan
• water-miscible organic solvents include alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; and glycol ethers such as ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and di
• the resin layer containing a vinyl alcohol-based polymer is a layer that imparts gas barrier properties, and can be provided by applying a coating agent (B) containing a vinyl alcohol-based polymer (hereinafter, may be simply referred to as coating agent (B)).
• a coating agent (B) containing a vinyl alcohol-based polymer hereinafter, may be simply referred to as coating agent (B)
• the vinyl alcohol polymer may be a hydrolyzate of a vinyl ester homopolymer or copolymer obtained by a known, commonly used method, or a reaction product of a hydrolyzate of a vinyl ester homopolymer or copolymer with an aldehyde obtained by a known, commonly used method.
• Vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate, etc., and may be used alone or in combination of two or more. It is preferable to use vinyl acetate.
• Polymerizable compounds that can be copolymerized with vinyl esters include ethylene, propene, 1-butene, isobutylene, 1,3-butadiene, isopropenyl acetate, 2-propenyl acetate, 3,4-diacetoxy-1-butene, 2,2-dialkyl-4-vinyl-1,3-dioxolane such as 2,2-dimethyl-4-vinyl-1,3-dioxolane, 3,4-dihydroxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-hydroxy-1-butene, 4-acyloxy-3-hydroxy-1-butene, 3,4-diacyloxy-2-methyl-1-butene, 4,5-dihydroxy-1-pentene, 4,5-diacyloxy-1-pentene, 4,5 3,4-diacyloxy-1-butenes such as 5,6-dihydroxy-1-hexene and 5,6-diacyloxy
• the amounts of these used can be adjusted as appropriate, but from the viewpoint of gas barrier properties, it is preferable to keep the amount of the polymerizable compound to 60 mol % or less of the total amount of the vinyl ester and the polymerizable compound (a2), and more preferably to keep it to 25 mol % or less.
• the degree of polymerization of the vinyl alcohol polymer or the vinyl ester polymer, which is the precursor of the vinyl alcohol polymer is not particularly limited, but is, for example, 500 to 10,000, more preferably 800 to 6,000, and even more preferably 1,000 to 3,000. This allows for a coating agent with an excellent balance between gas barrier properties and coating suitability.
• Aldehydes used for acetalization include aliphatic aldehydes such as formaldehyde, acetaldehyde, propylaldehyde, butylaldehyde, octylaldehyde, and dodecylaldehyde; alicyclic aldehydes such as cyclohexanecarbaldehyde; aromatic aldehydes such as benzaldehyde, naphthaldehyde, anthraldehyde, phenylacetaldehyde, tolualdehyde, dimethylbenzaldehyde, cuminaldehyde, and benzylaldehyde; cyclohexene aldehyde, dimethylcyclohexene aldehyde, acrylonitrile, and cyclohexane aldehyde; Examples of such aldehydes include unsaturated aldehydes such as chlorine; aldehy
• the acid catalyst used in the acetalization can be any conventional organic or inorganic acid, such as acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, or hydrochloric acid.
• suitable vinyl alcohol polymers include polyvinyl alcohol, ethylene vinyl alcohol, polyvinyl butyral, etc. One type may be used alone, or two or more types may be used in combination. From the viewpoint of the balance between gas barrier properties and adhesion, it is more preferable to use either polyvinyl alcohol or ethylene vinyl alcohol, or both.
• the vinyl alcohol polymer has a degree of saponification of preferably 90% or more, more preferably 95% or more, because of its excellent gas barrier properties. It may be 100%.
• the degree of saponification can be measured by FTIR, for example, using a Nicolet 5700 FTIR spectrometer controlled by OMNIC software.
• the vinyl alcohol polymer is preferably one obtained by acetalizing a precursor having a saponification degree of 95% or more.
• the vinyl alcohol polymer can be preferably used in combination with a polyalkyleneimine or a hydrazide.
• the polyalkyleneimine is a resin having a polyalkyleneimine skeleton, and is obtained by polymerizing one or more alkyleneimines (e.g., ethyleneimine, propyleneimine) by a conventional method.
• alkyleneimines e.g., ethyleneimine, propyleneimine
• the gas barrier properties of the coating agent (B) can be maintained while improving the adhesion to an olefin-based substrate.
• the polyalkyleneimine may be a linear polyalkyleneimine having a linear polyalkyleneimine chain, or a branched polyalkyleneimine having a branched polyalkyleneimine chain.
• Examples of polyalkyleneimines include polyethyleneimine and polypropyleneimine.
• the polyalkyleneimine may have a substituent (e.g., a hydroxypropyl group or a hydroxyethyl group) introduced into at least some of the nitrogen atoms of the polyalkyleneimine chain.
• Polyalkyleneimines modified with organometallic compounds such as tetraisopropyl titanate, tetranormalbutyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, polyhydroxytitanium stearate, titanium bisacetylacetonate, titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium ethylacetoacetate, titanium lactate, titanium triethanolamine, and titanium stearate may be used, and two or more types of polyalkyleneimines may be used in combination.
• organometallic compounds such as tetraisopropyl titanate, tetranormalbutyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, polyhydroxytitanium stearate,
• the polyalkyleneimine contributes to improving the adhesion between the vinyl alcohol polymer and the olefin film by the amino group (NHR group, NH2 group) and the ethylene group, and since it is effective in improving the adhesion, it is preferable that the polyalkyleneimine contains a branched polyalkyleneimine.
• the degree of branching of the polyalkyleneimine can be expressed by the ratio of primary, secondary, and tertiary amino groups possessed by the polyalkyleneimine.
• polyalkyleneimine having a ratio of primary amino groups of 20 to 40%, a ratio of secondary amino groups of 30 to 60%, and a ratio of tertiary amino groups of 20 to 35%.
• the ratios of primary, secondary, and tertiary amine groups contained in the polyalkyleneimine can be measured by 13 C-NMR spectroscopy.
• the branched polyalkyleneimine is preferably a branched polyethyleneimine.
• the number average molecular weight of the polyalkyleneimine is preferably 5,000 or more, more preferably 9,000 or more, and even more preferably 50,000 or more, because it has excellent adhesion. There is no particular upper limit, but an example is 100,000 or less.
• the number average molecular weight of the polyalkyleneimine is measured by GPC (gel permeation chromatography) using pullulan as the standard substance.
• the amount of polyalkylimine is preferably 1% by mass or more and 90% by mass or less of the total amount of the vinyl alcohol polymer and the polyalkylimine. This makes it possible to more reliably improve adhesion to olefin-based substrates while maintaining gas barrier properties. More preferably, it is 10% by mass or more and 50% by mass or less. If the coating agent of the present invention does not contain polyalkyleneimine, adhesion to olefin-based substrates is insufficient.
• Hydrazides include dicarboxylic acid dihydrazides containing 2 to 10, especially 4 to 6, carbon atoms, such as adipic acid dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, isophthalic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, and itaconic acid dihydrazide; and aliphatic water-soluble dihydrazines containing 2 to 4 carbon atoms, such as ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, and butylene-1,4-dihydrazine.
• the coating agent (B) may contain a resin other than the vinyl alcohol polymer.
• resins include cellulose resin, polyester, polyurethane, vinyl resin such as homopolymer or copolymer of olefin or styrene, acrylic resin, epoxy resin, amide resin, natural rubber, and composites thereof (e.g., core-shell type resin), and one or more of these resins may be used in combination. If the amount of resin is too large, the gas barrier properties may decrease, so the amount of resin is preferably kept to 10% by mass or less of the vinyl alcohol polymer. It is more preferable that the amount is 5% by mass or less, and even more preferable that the amount is 1% by mass or less. It may even be 0% by mass.
• the solvent for the coating agent (B) is preferably an aqueous solvent.
• aqueous solvent water, water-soluble organic solvents that dissolve in water, etc. can be used.
• water pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, etc., or ultrapure water can be used. From the viewpoint of long-term storage, it is preferable to use water that has been sterilized by ultraviolet irradiation or addition of hydrogen peroxide, etc., since this can prevent the growth of mold or bacteria.
• water-soluble organic solvents include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; diols such as butanediol, pentanediol, and hexanediol; glycol esters such as propylene glycol laurate; diethylene glycol ethers such as diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl, and carbitol; glycol ethers such as cellosolve, including propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, and pentyl alcohol; lactones such as sulfolane, esters
• the coating agent (B) may also contain additives such as layered inorganic compounds, crosslinking agents capable of reacting with functional groups possessed by the vinyl alcohol polymer or polyalkylimine (A2), inorganic fillers, defoamers, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, and leveling agents.
• additives such as layered inorganic compounds, crosslinking agents capable of reacting with functional groups possessed by the vinyl alcohol polymer or polyalkylimine (A2), inorganic fillers, defoamers, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, and leveling agents.
• layered inorganic compounds include natural smectites such as montmorillonite, synthetic smectites, natural mica, synthetic mica, hydrotalcite, and talc, as well as lipophilic treated smectites and lipophilic synthetic micas obtained by organically treating these compounds.
• the use of layered inorganic compounds improves the gas barrier properties of the coating agent, but tends to reduce adhesion to olefin-based substrates.
• the amount of layered inorganic compounds to be blended is preferably 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of resin (A), as this provides an excellent balance between gas barrier properties and adhesion.
• Crosslinking agents include aldehydes such as formalin and glutaraldehyde; acetals such as diacetalized glutaraldehyde; aliphatic polyisocyanates such as hexamethylene diisocyanate and its derivatives (adducts, nurates, biurets, etc.), aromatic aliphatic polyisocyanates such as xylylene diisocyanate and its derivatives, aromatic polyisocyanates such as toluene diisocyanate and its derivatives, and isocyanates such as urethane prepolymers which are reaction products of these isocyanates with polyols; epoxies; titanium, silicon, aluminum, zirconium, Examples of suitable isocyanates include organometallic compounds of boron or the like and alkoxides or the like; methylol ureas such as methylol urea and methylol melamine; carboxyl group-containing polymers such as polyacrylic acid polymers
• the method for applying the coating agent (B) is not particularly limited, and examples that can be used include spraying, spin coating, dipping, roll coating, blade coating, doctor roll, doctor blade, curtain coating, slit coating, screen printing, inkjet, dispensing, die coating, direct gravure, reverse gravure, flexography, knife coating, and dot coating.
• the thickness of the resin layer containing the vinyl alcohol polymer obtained by applying the coating agent (B) can be adjusted as appropriate depending on the type of substrate and the desired level of gas barrier properties, but is, for example, 0.2 ⁇ m to 2.0 ⁇ m. If the film thickness is too thin, the gas barrier properties cannot be expected to improve significantly, and if it is too thick, there is a risk of reduced adhesion.
• the gas barrier laminate film of the present invention can be obtained by applying the coating agent (B) onto the olefin resin film, drying it as necessary, providing a resin layer containing the vinyl alcohol polymer, and then providing the printing layer or the surface coating layer.
• the surface coating layer may be provided after the printing layer is provided.
• the gas barrier laminate film of the present invention can be further bonded to another substrate using an adhesive.
• another substrate can be laminated on the gas barrier laminate film of the present invention by an extrusion method.
• the other substrate can be the same as that described above.
• a two-liquid curing urethane solvent-based or solventless adhesive that is usually used for bonding films can be used. It is preferable to use an adhesive that has an aromatic ring concentration of the cured coating film of 0.5 mmol/g or more and 7.0 mmol/g or less, and it is more preferable to use an adhesive that has an aromatic ring concentration of 3.5 mmol/g or more and 7.0 mmol/g or less, since it will be a laminate with excellent gas barrier properties.
• First substrate/gas barrier coat layer First substrate/gas barrier coat layer/adhesive layer/second substrate First substrate/adhesive layer/gas barrier coat layer/second substrate First substrate/adhesive layer/gas barrier coat layer/vapor deposition layer/second substrate First substrate/gas barrier coat layer/printed layer/adhesive layer/second substrate First substrate/printed layer/gas barrier coat layer/adhesive layer/second substrate First substrate/printed layer/gas barrier coat layer/adhesive layer/second substrate First substrate/printed layer/gas barrier coat layer/adhesive layer/second substrate First substrate/printed layer/gas barrier coat layer/adhesive layer/second substrate Printed layer/first substrate/gas barrier coat layer/adhesive layer/second substrate.
• a coating layer that imparts functions such as heat resistance, releasability, and antistatic properties may be provided on the first substrate.
• the gas barrier laminate film of the present invention can be used as a multi-layer packaging material for the purpose of 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 resealing means.
• a laminate having a sealant layer is stacked with the sealant layer of the laminate facing each other, and the peripheral edge is heat-sealed to form a bag.
• bag-making methods include folding the laminate of the present invention or stacking it so that the inner layer surface (sealant layer surface) faces each other, and heat-sealing the peripheral edge using, for example, a side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, hem seal type, pleated seal type, flat bottom seal type, square bottom seal type, gusset type, or other heat seal type.
• the packaging material of the present invention can take various forms depending on the contents, the environment of use, and the form of use. Self-supporting packaging materials (standing pouches) are also possible. Heat sealing can be performed using known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high frequency seal, and ultrasonic seal.
• first substrate and the second substrate of the laminate of the present invention do not function as a sealant layer that will be the heat-sealed portion when forming the packaging material, a further sealant layer may be added.
• the sealant layer may be an additional substrate bonded with the adhesive of the present invention, or it may be an adhesive layer made of the adhesive of the present invention.
• 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.
• the contents to be filled include, for example, foods 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; agricultural processed products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, wild vegetable processed products, jams, peanut cream, salads, frozen vegetables, and potato processed products; livestock processed products such as ham, bacon, sausages, chicken processed products, and corned beef; and fish ham, These include processed seafood products such as sausages, fish paste products, kamaboko, nori, tsukudani (food boiled in soy
• 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.
• the gas barrier laminate film of the present invention can be recycled by known processing methods for recycling waste plastics.
• the recycled plastic of the present invention can be obtained by a known processing method for recycling waste plastics.
• An example of the processing method is shown below.
• the present invention is not limited to this, and various known recycled plastic processing methods can be applied.
• An example of the processing method is a method for producing recycled plastics, which includes the steps of crushing the gas barrier laminate film of the present invention, melting and kneading the crushed pieces, and pelletizing the melted and kneaded mixture.
• the crusher used in the step of crushing the gas barrier laminate film of the present invention is not particularly limited and any known crusher may be used.
• the crushed film pieces are physically blended by melt kneading, solvent cast blending, latex blending, polymer complex, etc.
• the melt kneading method is common. Examples of kneading devices include a tumbler, a Henschel mixer, a rotary mixer, a super mixer, a ribbon tumbler, a V blender, etc.
• the film pieces are melt kneaded by such a kneading device and then pelletized.
• a single-screw or multi-screw extruder is generally used for melt kneading pelletization, and the film pieces may be charged as they are, or may be charged after being compressed and reduced in volume with or without heating.
• a Banbury mixer, a roller, a co-kneader, a blast mill, a Prabender blastograph, etc. can also be used, which are operated batchwise or continuously.
• the film pieces may be used as molding resins and melt kneaded in the heating cylinder of a molding machine without melt kneading.
• Another example of a processing method is a method for producing recycled plastics that includes the steps of crushing the gas barrier laminate film of the present invention as necessary, immersing the laminate in a stripping liquid to separate and detach each layer, recovering each separated layer, melting and kneading the recovered crushed pieces, and pelletizing the melted and kneaded mixture.
• the crusher used in the step of crushing the gas barrier laminate film of the present invention is not particularly limited and any known crusher may be used.
• the crushed film pieces are immersed in a stripping liquid to separate and detach each layer of the laminate.
• the separation and detachment method (also simply called the detachment method) is a method in which the gas barrier laminate film of the present invention is immersed in a stripping liquid (detachment treatment liquid) to detach other layers provided on the substrate from the substrate.
• the term "detachment” refers to the separation of the substrate from other layers by the detachment layer being dissolved or swollen by the detachment treatment liquid and peeled off.
• the release treatment liquid may be any liquid capable of swelling and dissolving the adhesive layer, the printed layer, etc. in the gas barrier laminate film of the present invention, and may be appropriately selected in consideration of the ease of release of the release layer described below.
• Examples of such release liquids include water, an alkaline solution, and an acidic aqueous solution.
• the release treatment liquid is preferably an alkaline solution containing an inorganic base from the viewpoint of releasing materials of adhesive layers and printed layers that are commonly used in packaging materials.
• the inorganic base include sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium dihydrogen carbonate, potassium dihydrogen carbonate, etc. These inorganic bases are contained in a concentration of 0.1 to 10% by weight based on the total amount of the aqueous solution, and a concentration of 0.1 to 5% by weight is more preferable.
• the pH is preferably 9 or more, and more preferably 10 or more.
• the detachment treatment liquid may contain a surfactant.
• the surfactant is not particularly limited and any known surfactant may be used, for example, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., and among these, anionic surfactants, nonionic surfactants, or amphoteric surfactants are preferred.
• anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfates of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfates and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates.
• dodecylbenzenesulfonates include dodecylbenzenesulfonates, isopropylnaphthalenesulfonates, monobutylphenylphenol monosulfonates, monobutylbiphenylsulfonates, and dibutylphenylphenol disulfonates.
• nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkylol amides, alkyl alkanol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, and the like.
• polyoxyethylene nonylphenyl ether polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers are preferred.
• surfactants that can be used include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• silicone surfactants such as polysiloxane oxyethylene adducts
• fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers
• biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• surfactants can be used alone or in combination of two or more.
• the amount added is preferably in the range of 0.001 to 2 mass % of the total amount of the desorption treatment liquid, more preferably 0.001 to 1.5 mass %, and even more preferably 0.01 to 1 mass %.
• the desorption treatment liquid may contain a water-soluble organic solvent.
• the water-soluble organic solvent include water-soluble alcohols and water-soluble glycol ether-based organic solvents.
• examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dibutyl ether, diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol dimethyl ether, diethylene glycol monoethyl ether (carbitol), diethylene glycol diethyl ether (diethyl carbitol), diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol dibutyl ether, triethylene glycol mono Examples include methyl ether, triethylene glycol di
• the content of the water-soluble organic solvent in the desorption treatment liquid is preferably 0.1% by mass to 20% by mass, and more preferably 1% by mass to 10% by mass.
• the desorption treatment liquid may contain a water-insoluble organic solvent.
• the non-water-soluble organic solvent include alcohol-based solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon-based solvents such as hexane, heptane, and normal paraffin; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, and alkylbenzene; halogenated hydrocarbon-based solvents such as methylene chloride, 1-chlorobutane, 2-chlorobutane, 3-chlorobutane, and carbon tetrachloride; ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone-based solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclo
• the desorption treatment liquid may contain a defoaming agent.
• a defoaming agent When stirring or crushing the substrate during immersion, a large amount of bubbles may be generated, and if the bubbles remain, the bubbles may overflow during the plastic film recovery process. In addition, if a large amount of bubbles are caught in the desorption treatment liquid when crushing the substrate, the substrate may not be crushed to the desired size.
• Compounds commonly used as defoamers include water-soluble organic solvents and nonionic surfactants with low HLB values in the range of 1 to 3, but silicone compounds are particularly preferred because of their high defoaming ability. Among these, emulsion-type and self-emulsifying silicone compounds are preferred.
• the defoaming agent may be used alone or in combination of two or more types.
• the amount of the defoaming agent in the cleaning solution usable in step 1 is preferably in the range of 0.01 to 5% by weight, more preferably in the range of 0.02 to 4% by weight, and even more preferably in the range of 0.03 to 3% by weight.
• the temperature of the desorption treatment liquid is not particularly limited as long as the liquid state can be maintained, but it is usually preferable to carry out the treatment at a liquid temperature of 15 to 90° C.
• a desorption treatment liquid in which a surfactant or the like has been added to water it is preferable to adjust the liquid temperature according to the type of surfactant.
• the optimal temperature at which the cleaning effect is excellent varies depending on the type of surfactant, but is, for example, preferably 40° C. or higher, preferably 65° C. or higher, and preferably 85° C. or higher.
• a treatment tank in a state in which the desorption treatment liquid is heated or ultrasonically vibrated to the above temperature.
• the heating method There are no particular limitations on the heating method, and known heating methods using heat rays, infrared rays, microwaves, etc. can be used.
• ultrasonic vibration for example, a method in which an ultrasonic vibrator is attached to the treatment tank and ultrasonic vibration is applied to the warm water or alkaline solution can be used.
• Stirring the printed matter or laminate when immersing it in the release treatment solution is not essential and may be optional, but stirring allows for more efficient swelling. It is preferable to keep the stirring speed at a level that does not easily cause foaming even without the addition of a defoaming agent.
• the equipment and method for stirring are not particularly limited, and known methods can be used. Specific examples include a device equipped with a motor with stirring blades that can stir the cleaning liquid in a container, a device equipped with a device that generates ultrasonic waves, a device that can shake the container, a wet crusher, a water flow stirring method using a water flow pump, and a bubbling method using an inert gas such as nitrogen gas.
• the time for which the printed matter or laminate is immersed in the desorption treatment solution depends on the composition of the printed matter or laminate, but is generally in the range of 2 minutes to 48 hours. Note that in the printed matter or laminate, it is not necessary for the coating such as the printed layer to be completely detached 100% from the substrate, but it is preferable for at least 60% by weight of the 100% by weight coating to be detached, more preferably at least 70% by weight, even more preferably at least 80% by weight, and particularly preferably at least 90% by weight.
• the film may be immersed in the desorption treatment liquid once or several times. That is, the film may be immersed once and then the separated film substrate may be recovered, or the film may be immersed several times and then the film substrate may be recovered.
• the concentration of the desorption treatment liquid may be changed.
• known processes such as washing with water and drying may be added as appropriate.
• the detachment treatment liquid also promotes detachment of the plastic substrate by contacting the printed layer, primer layer, or the interface between the substrate and other layers from the edge of the printed matter or laminate. Therefore, it is preferable that the printed layer, adhesive layer, or primer layer is exposed on the cross section. Therefore, it is more preferable to include a step of fragmenting the printed matter or laminate by cutting or crushing.
• the method for crushing the plastic film is not particularly limited, and can be any known method. Crushing can be performed in an air atmosphere without the presence of liquids such as solvents, or in water or a cleaning solution. When crushing in an air atmosphere, a dry crusher can be used. When crushing in water or a cleaning solution, a wet crusher can be used, which can crush and pump simultaneously. When a wet crusher is used, the plastic film can be efficiently crushed, and the laminated plastic film can be peeled off into each layer.
• the immersion treatment in the aforementioned release treatment liquid it is preferable to provide a step of stirring the recovered substrate in water or in the aforementioned release treatment liquid. This step increases the rate at which the coating, such as the printed layer, is released from the substrate.
• a wet crusher for stirring.
• the rinse liquid is not particularly limited, and the above-mentioned desorption treatment liquid can be used as it is, but it is preferable that the rinse liquid contains an appropriate amount of an organic solvent.
• the organic solvent for example, it is preferable to contain one or more water-soluble alcohols or water-soluble solvents having a flash point of 21° C.
• the cleaning liquid contains a large amount of so-called water-soluble solvents including alcohols.
• the water-soluble solvent is preferably 30% by mass or more, preferably 40% by mass or more, preferably 50% by mass or more, preferably 60% by mass or more, preferably 70% by mass or more, preferably 80% by mass or more, preferably 90% by mass or more, and preferably 95% by mass or more.
• the equipment and method for stirring in the rinse solution are not particularly limited, and known methods can be used.
• Specific examples include a device equipped with a motor with stirring blades capable of stirring the cleaning solution in a container, a device equipped with a device that generates ultrasonic waves, a device that can shake the container, a wet crusher, a kneader, and the like.
• the desorption treatment liquid used in the desorption treatment step can be supplied to one or more recycling machines selected from a filter, a centrifuge, and an ultrafilter to recover the liquid, and can be reused after removing solid matter.
• Water, a rinse liquid, and the like can also be reused in the same way. While performing wet crushing, a recycle process for water, the desorption treatment liquid, the rinse liquid, and the like can be continuously operated to separate solid matter from the water, the wash liquid, and the rinse liquid.
• the separated and recovered substrate is dried by one or more methods selected from reduced pressure heating drying, hot air drying, pressurized compression drying, etc., to remove residual moisture.
• a pressurized compressor such as a Nippon Seam Co., Ltd. compression dehydrator, a Oike Iron Works Co., Ltd. pellet mill, or an Elcom Co., Ltd. Stella or briquette machine may be used to produce briquettes.
• the crushed material is pulverized to about 10 to 500 ⁇ m, and the density of the crushed material is high, so that the pressurized compression step can be omitted.
• the density varies depending on the material constituting the crushed material, but a higher density is preferable because it is easier to handle in a kneader.
• it is preferably 0.03 kg or more, more preferably 0.05 kg or more, more preferably 0.2 kg or more, and even more preferably 0.3 kg or more.
• the pellets of the present invention which are mainly made from recycled plastic, can exert their maximum effect by being recycled into non-oriented polyolefin films or molded products by injection molding or the like.
• the method of regenerating the non-oriented polyolefin film is not particularly limited, and can be obtained by a known film production method.
• a melt-kneading method using a general mixer such as a single-screw extruder, a twin-screw extruder, or a multi-screw extruder, or a method of dissolving or dispersing and mixing each component and then removing the solvent by heating, can be used.
• twin-screw extruder In consideration of workability, it is particularly preferable to use a single-screw extruder or a twin-screw extruder.
• a single-screw extruder When a single-screw extruder is used, a full-flight screw, a screw with a mixing element, a barrier flight screw, a fluted screw, or the like can be used without any particular limitation.
• the twin-screw kneading device is not particularly limited to a co-rotating twin-screw extruder, a counter-rotating twin-screw extruder, and the screw shape is also not particularly limited to a full-flight screw or a kneading disk type.
• a method of melting the film using a single-screw extruder or a twin-screw extruder, etc., and then forming a film using a T-die via a feed block or a multi-manifold may be used.
• the recycled film can be subjected to a surface modification treatment to improve suitability for subsequent processes as necessary.
• the surface of the film that comes into contact with other substrates can be modified to improve printability when used as a single film, and lamination suitability when used in a laminated form.
• a method of expressing functional groups by oxidizing the film surface such as corona discharge treatment, plasma treatment, and frame treatment, or a method of modifying the film by a wet process, such as coating an easy-adhesion layer, can be suitably used.
• pellets made primarily from virgin plastic may be molded into a molded body using conventional molding methods other than the above film-making, such as injection molding, extrusion molding, vacuum molding, compressed air molding, blow molding, etc., and used for various purposes.
• injection molding extrusion molding
• vacuum molding compressed air molding
• blow molding blow molding
• it can be used for everyday items, stationery, toys, sporting goods, home appliances, and automotive parts used in ordinary households, as well as films, sheets, and fibers. If there are no problems with hygiene, it can also be used in medical equipment, food containers, and food packaging materials.
• MDOPE1 in the examples and comparative examples is a uniaxially stretched high-density polyethylene film having a surface energy of 52 mN/m or more and a thickness of 25 ⁇ m.
• MDOPE2 in the examples and comparative examples is a uniaxially stretched low-density polyethylene film having a surface energy of 38 mN/m and a thickness of 23 ⁇ m.
• MDOPE3 in the examples and comparative examples is a uniaxially stretched high-density polyethylene film having a surface energy of 42 mN/m and a thickness of 26 ⁇ m.
• the BOPE in the examples and comparative examples is a biaxially oriented high-density polyethylene film having a surface energy of 41 mN/m and a thickness of 24 ⁇ m.
• OPP1 in the examples and comparative examples is a biaxially stretched polypropylene film having a surface energy of 38 mN/m and a thickness of 20 ⁇ m.
• OPP2 in the examples and comparative examples is a biaxially oriented polypropylene film having a surface energy of 42 mN/m and a thickness of 20 ⁇ m.
• Coating agent A1 A heat-resistant coating agent containing 88% cellulose propionate having a Tg of 159° C. in terms of solid content and 10% non-volatile content was prepared as coating agent A1.
• Coating agent A2 A surface coating agent containing a vinyl chloride-vinyl acetate copolymer having a Tg of 75° C. and a urethane resin was prepared as coating agent A2.
• Coating agent A3 A surface coating agent containing a vinyl chloride-vinyl acetate copolymer having a Tg of 75° C. and a polyester resin was prepared as Coating Agent A3.
• Coating agent B1 was prepared by adding 10 parts of isopropyl alcohol (hereinafter referred to as IPA) to 90 parts of Kuraray Poval 60-98 (fully saponified polyvinyl alcohol resin, manufactured by Kuraray Co., Ltd.) dissolved in water to a non-volatile content of 5%.
• IPA isopropyl alcohol
• Kuraray Poval 60-98 fully saponified polyvinyl alcohol resin, manufactured by Kuraray Co., Ltd.
• Coating agent B2 Coating agent B2 was prepared by adding 89 parts of Kuraray Poval 60-98 (Kuraray Co., Ltd., fully saponified polyvinyl alcohol resin) dissolved in water to a non-volatile content of 5%, 1 part of Epomin P-1000 (Nippon Shokubai, polyethyleneimine aqueous solution) and 10 parts of IPA.
• Coating agent B3 95 parts of Gohsenex Z-100 (manufactured by Mitsubishi Chemical Corporation, modified polyvinyl alcohol resin) dissolved in water to a non-volatile content of 10% was added to 5 parts of ADH (manufactured by Otsuka Chemical Co., Ltd., adipic acid dihydrazide) dissolved in a water/IPA mixed solvent to a non-volatile content of 5%, and the mixture was used to prepare Coating agent B3.
• ADH manufactured by Otsuka Chemical Co., Ltd., adipic acid dihydrazide
• Coating agents B1 to B3 were applied to the substrate using a bar coater so that the coating amount was 0.3 to 0.5 g/m 2 (solid content), and the substrate was dried by volatilizing the dilution solvent in a dryer set at a temperature of 70°C.
• ⁇ Coating method for printing layer> The coating surface of the coating agent (B) layer of the laminate prepared by the above "Coating method for coating agent (B) layer” or directly onto the substrate was coated with gravure ink Glosser 709 White Y3 manufactured by DIC Corporation using a gravure plate with a Helio 175 lines/inch plate in a gravure coater, and the dilution solvent was evaporated and dried with a dryer set at a temperature of 70° C.
• the coating amount of the printing layer was 1.4 g/ m2 .
• Coating agents A1 to A3 were applied to the printed layer coated surface of the laminate having the printed layer produced by the above "printed layer coating method" or directly to the substrate using a gravure plate with a helio 175 lines/inch plate in a gravure coater, and the dilution solvent was evaporated and dried in a dryer set at a temperature of 70°C, and then the laminate was cured at 40°C for 2 days.
• the coating amount of the coating agent (A) layer was 0.5 to 0.7 g/ m2 .
• gas barrier laminate films of Examples 1 to 18 and Comparative Examples 1 to 25 were obtained.
• the structures are shown in Tables 1 to 5.
• a cellophane tape (TF-12, manufactured by Nichiban Co., Ltd.) was applied to the outermost surface of each of the gas barrier laminate films of the Examples and Comparative Examples, and the degree of peeling when the tape was peeled off in one go was visually judged and rated on a 5-point scale. 5: No peeling 4: Less than 20% peeling 3: 20-70% peeling 2: 70% or more peeling 1: Completely peeled off
• the gas barrier laminate films of the Examples and Comparative Examples were brought into contact with a heat seal bar so as to directly contact the outermost surface of the laminate using a thermal gradient heat seal tester (manufactured by Tester Sangyo Co., Ltd.) at a sealing temperature of 100°C to 160°C, a pressure of 3 kg/cm2, and a time of 1 second.
• the presence or absence of shrinkage of the laminate around the sealed portion where the heat seal bar was in contact was visually confirmed.
• the temperature difference at which the laminate was able to suppress shrinkage was recorded to show how much it had improved compared to a film uncoated with coating agent (A), ink, and coating agent (B). If there was no difference in temperature, it was noted as "no effect.”
• the gas barrier laminated films of the examples and comparative examples were cut into 15 mm x 15 mm test pieces.
• the test pieces were immersed in a treatment liquid (2% NaOH aqueous solution) at 80°C, stirred at 800 rpm for 10 minutes using a magnetic stirrer, and then removed. After washing with ion-exchanged water and drying, the peeled area (%) of the coating agent (A), ink, and coating agent (B) was examined and evaluated according to the following criteria, and the results are summarized in a table.
• the gas barrier laminate film of the embodiment can be used to produce packaging materials with excellent functions such as oxygen barrier properties, water resistance, adhesion, and heat resistance, and also has deinking properties that are suitable for recycling.

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