Methods for recycling laminates

Abstract

This invention provides a method for stably producing plastic films using recycled plastic as a raw material for packaging films, using molding methods such as the T-die method, inflation method, calendering method, or co-extrusion multilayer T-die method. [Solution] A method for manufacturing a plastic film using recycled plastic as a raw material, wherein the content of polyolefin resin in the recycled plastic is 80% by mass or more, and the film is formed by a T-die method, an inflation method, or a calendering method; and a method for manufacturing a laminate, packaging material, and lid material using the same.

Description

[Technical Field]

[0001] The present invention relates to a method for recycling laminates. [Background technology]

[0002] In recent years, environmental pollution caused by the disposal and dumping of plastic products has become a serious concern, leading to increased demand for plastic product recycling. Among plastic products, plastic film packaging materials generally have a multilayer structure to meet different performance requirements depending on the application. For example, food packaging consists of a laminated structure formed by printing ink onto a first substrate and bonding it to a second substrate via an adhesive layer as needed. This laminated structure is then cut and heat-sealed to form the package shape. In such laminated structures, typified by food packaging, various plastic substrates are used as film substrates, including polyester, nylon, polypropylene, and polyethylene. Therefore, there is a demand for material recycling of laminated structures.

[0003] To address these demands, studies are underway to explore material recycling of laminated materials such as food packaging. For example, Patent Document 1 discloses a method in which impurities contained in the package are removed, the package is crushed, and after alkaline treatment or other necessary processes are performed, the materials are separated and recovered according to their specific gravity, and then the separated raw materials are melted to form pellets. Patent Document 2 discloses a method for manufacturing recycled plastic in which a laminate is melted and kneaded without performing a step to separate or detach layers other than the plastic substrate, such as the adhesive layer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-019003 [Patent Document 2] Patent No. 7425948 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a method for stably producing plastic films using recycled plastic as a raw material for packaging films by molding methods such as the T-die method, inflation method, calendering method, or co-extrusion multilayer T-die method. [Means for solving the problem]

[0006] In other words, the present invention is a method for producing a plastic film using recycled plastic as a raw material, wherein the content of polyolefin resin in the recycled plastic is 80% by mass or more, The present invention provides a method for manufacturing a plastic film by forming a film using one of the following methods: T-die method, inflation method, or calendering method.

[0007] The present invention also provides a method for manufacturing a laminate using a plastic film obtained by the manufacturing method described above.

[0008] The present invention also provides a method for manufacturing packaging materials using a plastic film obtained by the manufacturing method described above.

[0009] The present invention also provides a method for manufacturing a lid material using a plastic film obtained by the manufacturing method described above. [Effects of the Invention]

[0010] According to the present invention, recycled plastic can be used as a raw material for packaging film, and plastic films can be stably manufactured using molding methods such as the T-die method, inflation method, calendering method, or co-extrusion multilayer T-die method. These films can then be used for various packaging applications such as laminates, packaging materials, and lids. [Modes for carrying out the invention]

[0011] (Recycled plastic) The recycled plastic used in this invention is characterized by having a polyolefin resin content of 80% by mass or more in the recycled plastic, and being obtained by crushing and melt-kneading a plastic laminate having at least a first resin layer, an adhesive layer and / or a printed layer, and a second resin layer.

[0012] (Polyolefin resin content) The polyolefin resin content in recycled plastic can be determined by analysis, for example, infrared spectroscopy (IR), differential scanning calorimetry (DSC), or nuclear magnetic resonance (NMR). Furthermore, if the main raw material of the recycled plastic is a plastic laminate, the content can also be calculated by converting it from the mass percentage of the polyolefin resin layer constituting the plastic laminate. For example, if the plastic laminate has a multilayer structure including a layer such as a substrate made of polyolefin resin, and the total mass of the plastic laminate is used as the basis, the polyolefin resin content can be calculated using formula (1).

[0013] (Mass of polyolefin resin in the plastic laminate) / (Mass of the plastic laminate) × 100 (1)

[0014] The polyolefin resin content in the recycled plastic is 80% by mass or more, and preferably 85% by mass or more. The upper limit is 100% by mass.

[0015] (Plastic laminates that serve as raw materials for recycled plastics) In this invention, a plastic laminate is used as a raw material for recycled plastic. Plastic laminates currently have various laminates with different configurations in circulation according to various applications. For example, there are laminates with a laminated structure in which only a printing layer is provided on a resin layer serving as a base material, and there are also laminates having a laminated structure in which a plurality of resin layers, printing layers, and functional layers are adhered and laminated with an adhesive. Here, as an example, a plastic laminate having at least a first resin layer, an adhesive layer and / or a printing layer, and a second resin layer, which is the most commonly circulated plastic laminate, will be described.

[0016] (The first and / or second resin layer) The first and / or second resin layer can be used without particular limitation as long as it is a film or sheet excellent in chemical and physical strength (hereinafter, unless otherwise specified, the film also includes both films and sheets). For example, for food packaging, polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially stretched polyethylene film, OPE: biaxially stretched polyethylene film), polypropylene film (CPP: unstretched polypropylene film, OPP: biaxially stretched polypropylene film), ethylene vinyl alcohol copolymer, and polyolefin films such as gas barrier films having an olefin-based heat-sealing resin layer on one or both sides of a resin having gas barrier properties such as polyvinyl alcohol, polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc. can be mentioned.

[0017] On the other hand, since these resin layers determine the content of the polyolefin resin in the recycled plastic in the present invention, it is preferable that both the first and / or second resin layers are composed of a polyolefin resin so that the content of the polyolefin resin in the recycled plastic is 80% by mass or more. Hereinafter, in the present invention, the resin layer may sometimes be referred to as a resin film layer.

[0018] Specific examples of the polyolefin resin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, α-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 olefin resins such as polymethylpentene; and modified polyolefin resins obtained by modifying olefin resins with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or other unsaturated carboxylic acids.

[0019] It is also preferable to use a film formed of a material containing a biomass-derived component as the resin film layer. Biomass films are sold by various companies, and for example, sheets listed in the list of biomass-certified products described by the Japan Organic Resources Association, a general incorporated foundation, can be used.

[0020] Specifically, well-known films are those made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method of producing ethylene glycol via ethylene oxide from biomass ethanol by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from Indiaglycol Co., Ltd. can be preferably used.

[0021] Alternatively, products using biomass raw materials, distinguished by their biomass plasticity as defined by ISO 16620 or ASTM D6866, are also available. Radioactive carbon-14C exists in the atmosphere at a rate of 1 in 10¹² atoms, and this rate does not change even in atmospheric carbon dioxide. Therefore, this rate does not change in plants that fix 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 using an accelerator mass spectrometer, the proportion of plant-derived resin in the resin, i.e., the biomass plasticity, can be determined. Examples of plant-derived low-density polyethylene (PPE) biomass plastics with a biomass plastic content of 80% or more, preferably 90% or more, as defined by ISO 16620 or ASTM D6866, include Braskem's product names "SBC818," "SPB608," "SBF0323HC," "STN7006," "SEB853," and "SPB681," and films made from these materials can be suitably used.

[0022] For example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films and biomass polyethylene-polypropylene films, which contain polyethylene resin made from biomass-derived ethylene glycol, are also known. The polyethylene resin is not particularly limited except for the use of biomass-derived ethylene glycol as part of the raw materials. Examples include ethylene homopolymers and copolymers of ethylene and α-olefins with ethylene as the main component (ethylene-α-olefin copolymers containing 90% by mass or more of ethylene units). These can be used individually or in combination of two or more types. The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and examples include α-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. Among these, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferred from the viewpoint of making it even less likely for damage such as punctures or tears to occur when the films rub against each other, with a density of 0.900 to 0.950 g / cm³. 3 A linear low-density polyethylene resin is more preferable.

[0023] The biomass film may be a laminate formed by stacking multiple biomass films, or it may be a laminate formed by combining a conventional petroleum-based film with a biomass film.

[0024] The resin film layer may be subjected to some kind of surface treatment, such as physical treatments like corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, or flame treatment, or chemical treatments such as oxidation treatment using chemicals, or other treatments.

[0025] The aforementioned resin film layer can be manufactured using conventionally known film-forming methods such as extrusion, casting, T-die, cutting, inflation, and calendering. It may be an unstretched film, or, from the viewpoint of film strength, dimensional stability, and heat resistance, it may be stretched in one or two axes using a tenter method, tubular method, or the like.

[0026] The aforementioned resin film layer may contain additives as needed. Specifically, plastic compounding agents and additives such as elastomers, lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments may be added for the purpose of improving or modifying properties such as processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, mold release properties, flame retardancy, mold resistance, electrical properties, and strength. The amount of additives added should be adjusted within a range that does not affect other properties or recyclability.

[0027] The thickness of the resin film layer is not particularly limited and can be appropriately selected within the range of 0.1 to 300 μm from the viewpoint of moldability and transparency. Preferably, it is in the range of 0.3 to 100 μm. If it is less than 0.1 μm, the strength will be insufficient, and if it exceeds 300 μm, the rigidity will be too high, which may make processing difficult.

[0028] (Barrier layer) The resin film layer may, if necessary, be provided with a barrier layer to provide barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc. In particular, resin films with a polyolefin resin content of 80% by mass or more, especially polyethylene resin, tend to have poor gas barrier properties when used as a film for food packaging, for example. Therefore, it is preferable to provide a barrier layer. Generally, barrier layers include vapor-deposited layers with metals or inorganic compounds, and gas barrier coating layers primarily composed of raw materials known to have gas barrier properties, such as inorganic compounds or vinyl alcohol-based polymers. On the other hand, in the case of using recycled plastic as a raw material for packaging film, which is the subject of the present invention, it is preferable to use a vapor-deposited layer with metal oxides or inorganic compounds, a gas barrier coating layer coated and dried with a gas barrier coating agent primarily composed of raw materials known to have gas barrier properties, such as inorganic compounds or water-soluble polymers having hydroxyl groups, or a layer combining these, rather than using a metal vapor-deposited layer.

[0029] (deposited layer) For example, metal compounds such as aluminum oxide (AlOx), silicon dioxide (SiOx), zinc oxide, magnesium oxide, calcium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, and copper oxide may be used as the vapor-deposited layer of metal oxides or inorganic compounds. These metals or inorganic compounds may be used individually or in combination of two or more.

[0030] (Gas barrier coating layer) Gas barrier coating agents mainly composed of water-soluble polymers having hydroxyl groups include, for example, aqueous coating agents containing vinyl alcohol polymers, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate, and, if necessary, additives such as layered inorganic compounds, crosslinking agents that react with the functional groups of the vinyl alcohol polymer, adhesion enhancers, inorganic fillers, defoamers, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, and leveling agents. Specific examples of vinyl alcohol polymers that can provide the best gas barrier properties include polyvinyl alcohol, ethylene vinyl alcohol, and polyvinyl butyral. Vinyl alcohol polymers may also have reactive functional groups other than hydroxyl groups, such as acetoacetyl groups, carboxyl groups, anionic carboxyl groups, sulfonic acid groups, and anionic sulfonic acid groups. These may be used individually or in combination of two or more. These can be commercially available products, including, for example, Exevia (registered trademark) from Sumitomo Chemical, the SunBar (registered trademark) series from Sun Chemical, the Takelac WPB (registered trademark) series from Mitsui Chemicals, and LG-OX from Tokyo Ink Co., Ltd.

[0031] Additionally, solvent-based gas barrier coating agents such as the SB-504 / SA-201 series manufactured by DIC Corporation can also be used.

[0032] Alternatively, silicon compounds or hydrolysates of the silicon compounds, such as tetraethyl silicate (Si(OC2H5)4) (hereinafter sometimes referred to as TEOS), tetraalkoxysilanes such as tetramethyl silicate; trialkoxysilanes such as trimethoxymethylsilane, triethoxymethylsilane, and trimethoxyvinylsilane; dialkoxysilanes such as dimethoxydimethylsilane and diethoxydimethylsilane; monoalkoxysilanes such as methoxytrimethylsilane and ethoxytrimethylsilane, or their hydrolysates or partial hydrolysates are also known to be used in the gas barrier coating layer, and these may be combined to form the gas barrier coating layer.

[0033] The resin film layer may further be provided with a coating layer, if necessary, for purposes such as improving ink receptivity when providing the printing layer described later. Alternatively, a coating layer may be provided to impart functionality such as heat resistance and heat sealability.

[0034] (adhesive layer) The adhesive layer is a layer formed by drying, solidifying, or cross-linking an adhesive used in general lamination methods. Lamination methods include, for example, dry lamination, wet lamination, non-solvent lamination, and extrusion lamination. The adhesive layer is formed after the adhesive has hardened or dried.

[0035] Examples of adhesives used in the aforementioned dry lamination include one-component or two-component curing or non-curing vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others, as well as solvent-based, water-based, or emulsion-type adhesives. Examples of two-component curing adhesives include those made from a polyol composition and an isocyanate composition. Various adhesives, such as pressure-sensitive adhesives, may also be used. Examples of pressure-sensitive adhesives include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in organic solvents such as benzene, toluene, xylene, and hexane; or by compounding these rubber-based adhesives with tackifiers such as rosin aviethylene acid ester, terpene-phenol copolymer, and terpene-indene copolymer; or by dissolving acrylic copolymers with a glass transition temperature of -20°C or lower, such as 2-ethylhexyl acrylate-n-butyl acrylate copolymer and 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymer, in organic solvents.

[0036] Polyol compositions include polyols such as polyester polyols, polyether polyols, vegetable oil polyols, polyurethane polyols, and sugar alcohols. Two or more of these polyols can also be used in combination.

[0037] Examples of polyester polyols include polyester polyols obtained as reaction products of polyhydric alcohols and polycarboxylic acids, and lactone-based polyester polyols obtained by polycondensation reactions of aliphatic polyols with various lactones such as ε-caprolactone. It is preferable to use polyester polyols obtained as reaction products of polyhydric alcohols and polycarboxylic acids.

[0038] Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohesane, and 2,2,4-trimethyl-1,3-pentanediol;

[0039] Trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol, and other trifunctional or greater aliphatic polyols;

[0040] Bisphenols such as bisphenol A and bisphenol F; bisphenol alkylene oxide adducts obtained by adding ethylene oxide, propylene oxide, etc., to bisphenols such as bisphenol A and bisphenol F;

[0041] Examples include polyether polyols obtained by ring-opening polymerization of aliphatic diols or polyols with various cyclic ether-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, and these can be used individually or in combination of two or more.

[0042] Examples of polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; Aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid; and anhydrides or ester-forming derivatives of these aliphatic or dicarboxylic acids; Examples include p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of their dihydroxycarboxylic acids, and polybasic acids such as dimer acids, which can be used individually or in combination of two or more.

[0043] The molecular weight of polyester polyols is not particularly limited, but as an example, the number average molecular weight is between 250 and 20,000. The hydroxyl value of polyester polyols is not particularly limited, but as an example, it is between 5 mg KOH / g and 500 mg KOH / g.

[0044] Examples of polyether polyols include those obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of a polymerization initiator.

[0045] Polymerization initiators include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol;

[0046] Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and triol compounds of polypropylene glycol;

[0047] Examples include primary or secondary alkylamines such as ethylamine and diethylamine, amine compounds having multiple amino groups such as methylenediamine and ethylenediamine, and amine compounds having active hydrogen groups such as primary or secondary alkanolamines such as monoethanolamine and diethanolamine.

[0048] The molecular weight of the polyether polyol can be adjusted as appropriate, but one example is between 100 g / mol and 8000 g / mol. The hydroxyl value of polyether polyols can be adjusted as appropriate, but one example is between 10 mg KOH / g and 1200 mg KOH / g.

[0049] Examples of vegetable oil polyols include castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated form of castor oil), and castor oil alkylene oxide adducts of 5 to 50 moles.

[0050] Polyurethane polyols are reaction products of low-molecular-weight or high-molecular-weight polyols and polyisocyanate compounds. As the low-molecular-weight or high-molecular-weight polyol, the same polyhydric alcohols exemplified as raw materials for polyester polyols can be used. As the polyisocyanate compound, the same polyisocyanates that may be included in the isocyanate compositions described later can be used.

[0051] Examples of sugar alcohols include pentaerythritol, sucrose, xylitol, sorbitol, isomalt, lactitol, maltitol, and mannitol.

[0052] The polyol composition may contain an amine compound. The amine compound is a compound having an amino group. In this specification, an amino group refers to an NH2 group or an NHR group (where R is an alkyl or aryl group which may have a functional group).

[0053] Any known amine compound can be used without particular limitation, including methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropanamine-2,4,8,10-tetraoxaspirodoundecane, lysine, 2,2,4-trimethylhexamethylenediamine, hydrazine, piperazine, 2-hydroxyethylethylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, 1,3-diaminopropane,

[0054] 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bishexamethylenetriamine, 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornadiamine,

[0055] Amine compounds having multiple amino groups, such as bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, mensendiamine, bis(cyanoethyl)diethylenetriamine, 1,4-bis-(8-aminopropyl)-piperazine, piperazine-1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-(2"-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyureamines which are reaction products of the aforementioned polyamines and the aforementioned isocyanate components.

[0056] Primary or secondary alkanolamines such as monoethanolamine, monoisopropanolamine, monobutanolamine, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, and diisopropanolamine.

[0057] Examples include primary or secondary amines such as ethylamine, octylamine, laurylamine, myristylamine, stearylamine, oleylamine, diethylamine, dibutylamine, and distearylamine.

[0058] The amount of amine compound can be adjusted as appropriate depending on the purpose, but as an example, it is preferable to adjust the amine value of the polyol composition to be between 1 mg KOH / g and 100 mg KOH / g, and preferably between 10 mg KOH / g and 80 mg KOH / g.

[0059] In this specification, the amine value refers to the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1 g of the sample. There are no particular restrictions, and it can be calculated using known methods. If the chemical structure of the amine compound and, if necessary, the average molecular weight are known, it can be calculated using the formula: (number of amino groups per molecule / average molecular weight) × 56.1 × 1000. If the chemical structure or average molecular weight of the amine compound is unknown, it can be measured according to known amine value measurement methods, such as JIS K7237-1995.

[0060] The polyisocyanate composition comprises a polyisocyanate compound having multiple isocyanate groups. The polyisocyanate compound is not particularly limited and includes aromatic diisocyanates, aromatic aliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and burettes, nurates, adducts, allophanates, carbodiimide modified forms, uretdione modified forms of these diisocyanates, and urethane prepolymers obtained by reacting these polyisocyanates with polyols. These can be used individually or in combination.

[0061] Examples of aromatic diisocyanates include, but are not limited to, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate (also called polymeric MDI or crude MDI), 1,3-phenylenediisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylenediisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

[0062] Aromatic aliphatic diisocyanates refer to aliphatic isocyanates having one or more aromatic rings in their molecule, and include, but are not limited to, m- or p-xylylene diisocyanate (also known as XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (also known as TMXDI).

[0063] Examples of aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate, but are not limited to these.

[0064] Examples of alicyclic diisocyanates include, but are not limited to, 3-isocyanate-methyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,4-bis(isocyanate-methyl)cyclohexane.

[0065] For the synthesis of urethane prepolymers, polyols similar to those exemplified as raw materials for polyester polyols above can be used alone or in combination of two or more. It is preferable to use at least one polyalkylene glycol or polyester polyol with a molecular weight of 200 to 3000 g / mol.

[0066] The polyisocyanate composition may contain, for example, 5 to 50% by mass of diisocyanate monomer for the purpose of adjusting its viscosity to be suitable for the non-solvent lamination method, or its content may be reduced to 5% by mass or less, more preferably 1% by mass or less, more preferably 0.5% by mass or less, and more preferably 0.1% by mass or less of the polyisocyanate composition from the viewpoint of occupational safety and health.

[0067] The diisocyanate monomer can be removed by distilling it under reduced pressure using a short-pass distillation apparatus or a thin-film distillation apparatus. The degree of reduced pressure and distillation temperature are adjusted as appropriate depending on the diisocyanate monomer to be removed, but as an example, they are 0.1 mbar or less and 120°C to 190°C. The diisocyanate monomer removal process may be performed multiple times.

[0068] The diisocyanate monomer content can be measured by gas chromatography using an internal standard, for example, according to ASTM D 3432. Alternatively, it can be measured by liquid chromatography under the following conditions.

[0069] Equipment: Waters Corporation "ACQUITY UPLC H-Class" Data processing: Empower-3 manufactured by Waters Corporation Column: Waters Corporation "ACQUITY UPLC HSS T3" (100 mm × 2.1 mmφ, 1.8 μm) 40℃ Eluent: Ammonium formate aqueous solution / methanol, 0.3 mL / min Detector: PDA Sample preparation: 1. Dissolve 100 mg of appropriately blocked sample in 10 ml of THF (for LC). 2. Vortex for 30 seconds. 3. Dilute as appropriate with the eluent (mobile phase). The liquid was passed through a 4.0.2 μm filtration filter to obtain the measurement sample. Calculation of area ratio: Calculated using the maximum absorption wavelength for the target material.

[0070] The adhesive may be solvent-based or solvent-free. In this specification, a solvent-based adhesive refers to a form in which the polyol composition and polyisocyanate composition contain highly soluble organic solvents such as esters like ethyl acetate, butyl acetate, and cellosolve acetate, ketones like acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone, ethers like tetrahydrofuran and dioxane, aromatic hydrocarbons like toluene and xylene, halogenated hydrocarbons like methylene chloride and ethylene chloride, dimethyl sulfoxide, and dimethyl sulfamide. A solvent-free adhesive refers to a form that substantially does not contain these organic solvents. If trace amounts of organic solvent remain in the polyol composition and polyisocyanate composition due to incomplete removal of the components of the polyol composition and polyisocyanate composition or organic solvents used as reaction media during the manufacture of their raw materials, it is understood that the adhesive is substantially solvent-free. Furthermore, if the polyol composition contains low molecular weight alcohol, the low molecular weight alcohol reacts with the polyisocyanate composition to become part of the coating film, so it does not need to be volatilized after coating. Therefore, this form is also treated as a solvent-free adhesive, and low molecular weight alcohols are not considered organic solvents.

[0071] The adhesive may contain components other than those mentioned above, such as urethane catalysts, acid anhydrides, coupling agents, pigments, plasticizers, phosphoric acid derivatives, etc. These components may be included in either or both of the polyol composition or the polyisocyanate composition, or they may be prepared separately and mixed with the polyol composition or polyisocyanate composition immediately before application of the adhesive.

[0072] It is preferable to use the adhesive in a formulation such that the ratio [NCO] / [OH] of the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition to the number of moles of hydroxyl groups [OH] contained in the polyol composition is 0.5 to 5.0.

[0073] The adhesive layer is formed by applying an adhesive directly to either the first or second resin layer, or via an optional layer, bonding it to the other resin layer, and then performing an aging treatment. Alternatively, a polyol composition can be applied to either the first or second resin layer, and a polyisocyanate composition can be applied to the other resin layer. The coated surfaces can then be brought into contact and pressed together to laminate the first and second resin layers, followed by an aging treatment to cure the adhesive and form the adhesive layer. As an example, the aging temperature is room temperature to 70°C, and the aging time is 6 to 240 hours. The amount of adhesive applied is adjusted as appropriate, but as an example, it is 1 g / m². 2 More than 5g / m 2 The following applies:

[0074] (Gas barrier adhesive layer) In addressing the challenges of the present invention, when recycled plastic is used as a raw material for packaging film, as described above, it is preferable to use a metal vapor-deposited layer rather than a metal vapor-deposited layer. This is preferable to a vapor-deposited layer of metal oxides or inorganic compounds, or a gas barrier coating layer coated and dried using a gas barrier coating agent mainly composed of raw materials known to have gas barrier properties, such as inorganic compounds or water-soluble polymers having hydroxyl groups, or a layer combining these. On the other hand, since the metal vapor-deposited layer has the best barrier properties, it is preferable in some cases to combine it with an adhesive that has gas barrier properties.

[0075] Examples of gas barrier adhesives include a two-component adhesive comprising a polyol composition (X) containing at least one polyester polyol (A) from (A1) to (A3) listed below, and a polyisocyanate composition (Y) containing a compound having at least two isocyanate groups in one molecule (hereinafter also simply referred to as an isocyanate compound (B)).

[0076] (1) Polyester polyol (A1) obtained by polycondensation of a polycarboxylic acid containing an ortho-directing polycarboxylic acid with a polyhydric alcohol. (2) Polyester polyol having an isocyanuric ring (A2) (3) Polymerizable carbon-carbon double bond polyester polyol (A3)

[0077] Examples of ortho-directing polycarboxylic acids used in the synthesis of polyester polyol (A1) include orthophthalic acid or its acid anhydride, naphthalene 2,3-dicarboxylic acid or its acid anhydride, naphthalene 1,2-dicarboxylic acid or its acid anhydride, anthraquinone 2,3-dicarboxylic acid or its acid anhydride, and 2,3-anthracenecarboxylic acid or its acid anhydride. These compounds may have substituents on any carbon atom of the aromatic ring. Examples of substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, or naphthyl group.

[0078] The polycarboxylic acid used in the synthesis of polyester polyol (A1) may include polycarboxylic acids other than ortho-directing polycarboxylic acids. Examples of polycarboxylic acids other than ortho-directing polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid and acid anhydrides or ester-forming derivatives of these dicarboxylic acids, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids, and aromatic polycarboxylic acids, and one or more of these can be used in combination. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid, and their acid anhydrides are preferred.

[0079] When the polycarboxylic acid includes polycarboxylic acids other than ortho-directing polycarboxylic acids, it is preferable that the proportion of ortho-directing polycarboxylic acids to the total amount of polycarboxylic acids is 40 to 100% by mass.

[0080] 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, and cyclohexanedimethanol, and more preferably contains ethylene glycol.

[0081] Polyhydric alcohols other than those listed above may be used in combination. Examples 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 glycerin, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl) isocyanurate, 1,2,4-butanetriol, pentaerythritol, and dipentaerythulitol; hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, and aromatic polyhydric phenols such as ethylene oxide extensions thereof and hydrogenated alicyclic groups.

[0082] When polyester polyol (A1) has three or more hydroxyl groups (referred to as polyester polyol (a1) for convenience), some of the hydroxyl groups may be modified with acid groups. Such polyester polyols will also be referred to as polyester polyol (A1') below. Polyester polyol (A1') is obtained by reacting polyester polyol (a1) with a polycarboxylic acid or its acid anhydride. The proportion of hydroxyl groups modified with the polycarboxylic acid is preferably 1 / 3 or less of the hydroxyl groups present in polyester polyol (a1). Examples of 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.

[0083] Polyester polyol (A2) can be obtained, for example, by reacting a triol having an isocyanuric ring with a polycarboxylic acid containing an ortho-directing aromatic polycarboxylic acid and a polyhydric alcohol. Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acids such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid. The ortho-directing aromatic polycarboxylic acid, polycarboxylic acid, and polyhydric alcohol can be the same as those used in polyester polyol (A1).

[0084] As the 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. As the ortho-directing aromatic polycarboxylic acid, it is preferable to use orthophthalic anhydride. As the polyhydric alcohol, it is preferable to use ethylene glycol.

[0085] Polyester polyol (A3) can be obtained by using components having polymerizable carbon-carbon double bonds as polycarboxylic acids and polyhydric alcohols.

[0086] Examples of polycarboxylic acids having polymerizable carbon-carbon double bonds include maleic anhydride, maleic acid, fumaric acid, 4-cyclohexene-1,2-dicarboxylic acid and its acid anhydrides, and 3-methyl-4-cyclohexene-1,2-dicarboxylic acid and its acid anhydrides. Maleic anhydride, maleic acid, and fumaric acid are preferred because it is presumed that the fewer carbon atoms there are, the less the molecular chain becomes excessively flexible and therefore less permeable to oxygen. Examples of polyhydric alcohols containing polymerizable carbon-carbon double bonds include 2-butene-1,4-diol.

[0087] In addition to the above, polycarboxylic acids and polyhydric alcohols that do not have polymerizable carbon-carbon double bonds may be used in combination. Such polycarboxylic acids and polyhydric alcohols can be the same as those used for polyester polyols (A1) and (A2). The polycarboxylic acid is preferably at least one selected from the group consisting of succinic acid, 1,3-cyclopentanedicarboxylic acid, orthophthalic acid, orthophthalic acid acid anhydride, and isophthalic acid; it is more preferable to use at least one of orthophthalic acid and its acid anhydride. The polyhydric alcohol is preferably at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol; it is more preferable to use ethylene glycol.

[0088] The hydroxyl value of polyester polyol (A) is preferably 20 mg KOH / g or more and 400 mg KOH / g or less, and preferably 100 mg KOH / g or more and 400 mg KOH / g or less. If the polyester polyol (A) has an acidic group, the acid value is preferably 200 mg KOH / g or less. The hydroxyl value of polyester polyol (A) can be measured using the hydroxyl value measurement method described in JIS-K0070, and the acid value can be measured using the acid value measurement method described in JIS-K0070.

[0089] The number-average molecular weight of polyester polyol (A) is typically between 300 and 5000. The number-average molecular weight can be calculated from the obtained hydroxyl value and the number of functional groups of hydroxyl groups in the design.

[0090] The glass transition temperature of polyester polyol (A) is preferably -30°C to 80°C, more preferably 0°C to 60°C, and even more preferably 25°C to 60°C, in order to balance adhesion to the substrate and gas barrier properties.

[0091] Polyester polyol (A) may also be a polyester polyurethane polyol obtained by urethane elongation of polyester polyols (A1) to (A3) through reaction with a diisocyanate compound, resulting in a number average molecular weight of 1,000 to 15,000. Since the urethane-elongated polyester polyol contains molecular weight components above a certain level and urethane bonds, it has excellent gas barrier properties, excellent initial cohesive strength, and is excellent as an adhesive for lamination.

[0092] A polyisocyanate composition (Y), which is a component of a two-component adhesive having gas barrier properties, contains an isocyanate compound (B). As the isocyanate compound (B), conventionally known compounds can be used without particular limitation, including tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, or trimers of these isocyanate compounds, and adducts obtained by reacting an excess amount of these isocyanate compounds with low molecular weight active hydrogen compounds such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, metaxylylenediamine and their alkylene oxide adducts, various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds of polyamides. Polyester polyisocyanates obtained by reacting polyester polyols (A1) to (A3) with a diisocyanate compound in an isocyanate excess ratio of hydroxyl groups to isocyanate groups may also be used. These can be used individually or in combination of two or more.

[0093] In addition, blocked isocyanates may be used as isocyanate compounds. Examples of isocyanate blocking agents include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime; alcohols such as methanol, ethanol, propanol, and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propyrolactam; and other examples include aromatic amines, imides, active methylene compounds such as acetylacetone, acetoacetate ester, and ethyl malonate ester, mercaptans, imines, ureas, diaryl compounds, and sodium bisulfite. Blocked isocyanates are obtained by an addition reaction between the above-mentioned isocyanate compound and an isocyanate blocking agent using a known and conventional method.

[0094] In particular, isocyanate compounds having a skeleton derived from xylylene diisocyanate, hydrogenated xylylene diisocyanate, toluene diisocyanate, or diphenylmethane diisocyanate are more preferable because they provide good gas barrier properties.

[0095] Examples of such isocyanate compounds include diisocyanate trimers, biuret compounds synthesized by reaction with amines, and adduct compounds formed by reaction with alcohols. Compared to trimers and biuret compounds, adduct compounds are preferable when the adhesive is solvent-based because they have better solubility in organic solvents used in solvent-based adhesives. As adduct compounds, adduct compounds formed by reaction with alcohols appropriately selected from the above low molecular weight active hydrogen compounds can be used, but among these, adduct compounds with ethylene oxide adducts of trimethylolpropane, glycerol, triethanolamine, and metaxyldiamine are preferred.

[0096] Furthermore, when using a polyol composition (X) that includes a polyester polyol in which a carboxylic acid group remains, such as polyester polyol (A1'), the polyisocyanate composition (Y) may also contain an epoxy compound. Examples of epoxy compounds include diglycidyl ether of bisphenol A and its oligomers, diglycidyl ether of hydrogenated bisphenol A and its oligomers, diglycidyl orthophthalate, diglycidyl isophthalate, diglycidyl terephthalate, diglycidyl p-oxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipic acid, diglycidyl sebacate, ethylene glycol diglycidyl ether, and propylene glycol diglycidyl Examples include ethers, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidylpropylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and triglycidyl ethers of glycerol alkylene oxide adducts.

[0097] When using epoxy compounds, a commonly known epoxy curing accelerator may be added as appropriate to accelerate curing, provided that the objectives of the present invention are not impaired.

[0098] When using a polyol composition (X) that includes a polyol having a polymerizable carbon-carbon double bond, such as polyester polyol (A3), a known polymerization catalyst can be used in combination to promote the polymerization of the carbon-carbon double bond. One example of such a catalyst is a transition metal complex. The transition metal complex is not particularly limited as long as it is a compound that has the ability to oxidize the polymerizable double bond. For example, salts of metals such as cobalt, manganese, lead, calcium, cerium, zirconium, zinc, iron, and copper with octic acid, naphthenic acid, neodecanoic acid, stearic acid, resin acid, tall oil fatty acid, tung oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, etc. can be used. The amount of transition metal complex added is preferably 0 to 10 parts by mass, more preferably 0 to 3 parts by mass, relative to the resin solids contained in the polyol composition (X).

[0099] In this invention, it has been found that when a plastic laminate using the gas barrier adhesive is used as a raw material for recycled plastic, the generation of gels in the recycled plastic can be suppressed more effectively. Therefore, a plastic film made using the gas barrier adhesive and recycled plastic as a raw material can be formed into a film with better performance.

[0100] (Printing layer) When a laminate has a printed layer, the printing is done using printing ink between the first resin layer and the adhesive layer, or on the side of the first resin layer opposite the adhesive layer. Examples include letters, figures, symbols, and other desired patterns or information.

[0101] The printing method and inks are not particularly limited, and known printing methods and inks can be used. The films used as the substrate often utilize printing inks produced by gravure printing, flexographic printing, lithographic offset printing, and inkjet recording printing methods. Printing inks that combine these methods with curing methods using active energy rays such as ultraviolet (UV), LED, or electron beam (EB), or by heat, are also used. Furthermore, depending on the solvent used, these may be referred to as water-based inks or organic solvent-based inks.

[0102] Specifically, these include gravure printing inks and flexographic printing inks (in some industries, gravure printing inks and flexographic printing inks are referred to as liquid inks), UV-curable inks for lithographic offset printing, electron beam-curable inks for lithographic offset printing, UV-curable inks for inkjet recording printing, and electron beam-curable inks for inkjet recording printing. Biomass inks made from biomass raw materials are also used as appropriate.

[0103] The printing ink may contain resin, colorant, and solvent as essential components, or it may be a so-called clear ink that contains resin and solvent but substantially no colorant. The printing layer may be provided over the entire surface of the first resin layer, or only on a portion of it.

[0104] Taking the case where the printing ink is gravure printing ink or flexographic printing ink as an example, the resin used in the printing ink is 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 acetal obtained by reacting vinyl acetate resin with an aldehyde such as butyraldehyde under acidic conditions, polyvinyl chloride resin, chlorinated polypropylene resin, cellulose resin, epoxy resin, alkyd resin, rosin 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. Preferably, at least one or more selected from polyurethane resin and polyvinyl acetal are used. Furthermore, it is preferable that the resin used in the printing ink contains 0.8% by mass or less of chlorine-containing resins such as vinyl chloride-vinyl acetate copolymer resins, or resins having nitro groups such as nitrocellulose resins. It is also preferable that the ink does not contain chlorine-containing resins such as vinyl chloride-vinyl acetate copolymer resins, or resins having nitro groups such as nitrocellulose resins.

[0105] Colorants used in printing inks include inorganic pigments such as titanium dioxide, 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.

[0106] The organic solvents used in printing inks preferably do not contain aromatic hydrocarbon organic solvents. More specifically, examples include alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and butanol; ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based 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. One or more of these can be used in combination.

[0107] The liquid printing ink used in this invention may also preferably be a gravure printing ink or flexographic printing ink made from plant-derived raw materials, taking into consideration the construction of a sustainable circular society.

[0108] Examples of plant-derived raw materials include cellulose acetate propionate resin and nitrated cotton resins, polyamide resins using dimer acids or polymerized fatty acids derived from natural oils such as soybean oil, palm oil, and rice bran oil, as well as polycarboxylic acids such as succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, glutaric acid, and malic acid, as well as polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer ol, and isosorbide, and polyisocyanates such as 1,5-pentamethylene diisocyanate and dimer isocyanate. Biomass polyurethanes synthesized from these plant-derived raw materials and rosin resins are also available.

[0109] For biomass gravure printing inks or flexographic printing inks, commercially available products listed by the Japan Organic Resources Association can also be used.

[0110] The area of ​​the printed layer relative to the area of ​​the laminate or packaging material is preferably 50% or less. Furthermore, the printed layer is preferably designed to be light in color. Specifically, the density measured using a densitometer with ISO status T as the density standard, a viewing angle of 2°, and a light source D50 is preferably 0.8 or less, more preferably 0.5 or less. For example, an eXactAdvance manufactured by X-rite can be used as the densitometer.

[0111] The above describes a plastic laminate having at least a first resin layer, an adhesive layer and / or a printed layer, and a second resin layer as an example of a specific embodiment and as an example of the most commonly distributed plastic laminate. However, the plastic laminate used as the raw material for the recycled plastic in the present invention is not limited to this, and any recycled plastic can be used as long as the polyolefin resin content in the resulting recycled plastic is 80% by mass or more.

[0112] Examples include a plastic laminate in which a printed layer is directly laminated onto a first resin layer, and a plastic laminate having a first resin layer, an adhesive layer and / or a printed layer, a second resin layer, as well as a metal vapor deposition layer, an inorganic vapor deposition layer, various coating layers, a third resin layer, etc. Furthermore, packaging materials using the aforementioned plastic laminate can also be used in the same manner. Furthermore, if the manufacturing process of recycled plastics includes a step in which the materials are impregnated with a desorption treatment solution to separate them into individual substrates, a primer layer may be laminated to facilitate separation and desorption.

[0113] (Methods for manufacturing recycled plastics) Recycled plastic can be obtained by crushing (grinding) the plastic laminate or packaging material using the plastic laminate, and then melting and kneading it. As an example of a specific embodiment, recycled plastic can be obtained by a manufacturing method that includes the steps of: directly crushing the plastic laminate or packaging material using the plastic laminate, for example by impregnating it with a desorption treatment liquid to separate the recovered material into its respective base material, or the plastic laminate or packaging material using the plastic laminate itself; melting and kneading the crushed film pieces; and pelletizing the melted and kneaded mixture.

[0114] (Crushing process) In the crushing process, it is preferable to crush (including cutting) the laminate or packaging material into small, rectangular pieces with sides of approximately 1 to 50 mm, preferably 3 to 30 mm, and more preferably 3 to 15 mm. The crushing method may be so-called wet crushing, where the crushing is carried out in water or a washing solution, or dry crushing, where the crushing is carried out in an air atmosphere where no liquid such as a solvent is present.

[0115] While there are no particular limitations on the type of wet crusher, a wet crusher capable of simultaneously crushing, dispersing, mixing, and pumping solid material in a liquid is preferred. Specifically, a crusher having a mechanism for crushing solid material in a liquid using shear force and / or frictional force is preferred, as is a crusher having a mechanism for crushing and pumping plastic film. Examples of such wet crushers include wet crushing pumps, colloid mills, and grinders.

[0116] Dry crushers are not particularly limited, but examples include mycoloiders, mascoloiders, ball mills, power mills, pin mills, air-jet mills, shear friction mills, cutter mills, impact mills (hammer mills, ball mills), roll mills, homogenizers, ultrasonic crushers, etc.

[0117] (Separation and desorption process) The separation and desorption process may be performed before crushing the laminate or packaging material, but it is more efficient and preferable to perform it after crushing. The separation and desorption process is a process of obtaining recovered materials separated from each base material by impregnating the laminate or packaging material, either before or after crushing, with a desorption treatment liquid. Specifically, for example, this method involves immersing the laminate or packaging material in a desorption treatment liquid to desorb other layers provided on the base material. Desorption refers to the separation of the base material from other layers by the desorption layer dissolving or swelling and peeling off due to the desorption treatment liquid.

[0118] (Desorption treatment solution) The desorption treatment liquid can be appropriately selected as long as it swells and dissolves the adhesive layer, printed layer, etc., in the laminate or packaging material. Examples of such desorption liquids include water, alkaline solutions, and acidic aqueous solutions. The desorption treatment solution is preferably an alkaline solution containing an inorganic base, from the viewpoint of desorbing the adhesive layer and printing layer materials commonly used in packaging materials.

[0119] (Inorganic bases) Examples of inorganic bases include sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium dihydrogen carbonate, and potassium dihydrogen carbonate. These inorganic bases are included in a concentration of 0.1 to 10% by weight relative to the total volume of the aqueous solution, with a concentration of 0.1% to 5% by weight being more preferable. The pH is preferably 9 or higher, and preferably 10 or higher.

[0120] (Surfactants) The desorption treatment liquid may contain a surfactant. The surfactant is not particularly limited and any known surfactant can be used, but examples include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, among which anionic surfactants, nonionic surfactants, or amphoteric surfactants are preferred.

[0121] Examples of anionic surfactants include alkylbenzene sulfonates, alkylphenyl sulfonates, alkylnaphthalene sulfonates, higher fatty acid salts, sulfate salts of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfate salts and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates. Specific examples of these include dodecylbenzene sulfonate, isopropylnaphthalene sulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenyl sulfonate, and dibutylphenylphenol disulfonate.

[0122] Examples of 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 alkylolamides, alkyl alkanolamides, acetylene glycols, oxyethylene adducts of acetylene glycols, polyethylene glycol polypropylene glycol block copolymers, etc. Among these, polyoxyethylene nonylphenyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene dodecylphenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylolamides, acetylene glycols, oxyethylene adducts of acetylene glycols, and polyethylene glycol polypropylene glycol block copolymers are preferred.

[0123] Other surfactants that can be used include silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spicrispolic acid, rhamnolipid, and lysolecithin.

[0124] These surfactants can be used individually or in mixtures of two or more types. When surfactants are added, the amount added is preferably in the range of 0.001 to 2% by mass, more preferably 0.001 to 1.5% by mass, and even more preferably 0.01 to 1% by mass, relative to the total amount of the desorption treatment liquid.

[0125] (Water-soluble organic solvent) The desorption treatment solution may contain a water-soluble organic solvent. Examples of water-soluble organic solvents include water-soluble alcohols and water-soluble glycol ether-based organic solvents. Specifically, these 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, and triethylene glycol mono Examples include methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methylene dimethyl ether (methylal), propylene glycol monobutyl ether, tetrahydrofuran, acetone, diacetone alcohol, acetonylacetone, acetylacetone, ethylene glycol monomethyl ether acetate (methyl cellosolve acetate), diethylene glycol monomethyl ether acetate (methyl carbitol acetate), diethylene glycol monoethyl ether acetate (carbitol acetate), ethyl hydroxyisobutyrate, and ethyl lactate, which can be used individually or in combination of two or more.

[0126] The content of the water-soluble organic solvent in the desorption treatment liquid is preferably 0.1% to 20% by mass, and more preferably 1% to 10% by mass.

[0127] (Non-water-soluble organic solvents) The desorption treatment solution may contain a non-water-soluble organic solvent. Examples of non-water-soluble organic solvents include alcohol-based solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon-based solvents such as hexane, heptane, and n-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 cyclohexanone; and ether-based solvents such as ethyl ether and butyl ether. These can be used individually or in combination of two or more.

[0128] (Antifoaming agent) The defoaming solution may contain an antifoaming agent. During immersion, stirring and crushing of the substrate may generate a large amount of foam, and if foam remains, it may overflow during the plastic film recovery process. Also, if a large amount of foam is incorporated into the defoaming solution during substrate crushing, the substrate may not be crushed to the desired size.

[0129] Commonly used defoaming agents include water-soluble organic solvents and nonionic surfactants with low HLB values ​​in the range of 1 to 3. However, silicone compounds are particularly preferred due to their high defoaming ability. Among these, emulsion-type and self-emulsifying silicone compounds are preferred.

[0130] The defoaming agent may be used alone or in combination of two or more types. In step 1, the amount of the defoaming agent in the usable cleaning solution 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.

[0131] (Liquid temperature) The temperature of the desorption treatment solution is not particularly limited as long as it can maintain a liquid state, but it is generally preferable to perform the treatment at a temperature of 15 to 90°C. When using a desorption treatment solution prepared by adding a surfactant to water, it is preferable to adjust the temperature according to the type of surfactant. The optimal temperature for excellent cleaning effect varies depending on the type of surfactant, but for example, 40°C or higher is preferable, 65°C or higher is preferable, and 85°C or higher is preferable. Furthermore, it is preferable to immerse the target laminate in a treatment tank, for example, while the desorption treatment liquid is heated to the above temperature or subjected to ultrasonic vibration. There are no particular limitations on the heating method, and known heating methods such as those using heat rays, infrared rays, and microwaves can be employed. As for ultrasonic vibration, for example, a method can be employed in which an ultrasonic transducer is attached to the treatment tank and ultrasonic vibration is applied to the hot water or alkaline solution.

[0132] (stir) While stirring is not mandatory and is optional when immersing in the desorption treatment solution, stirring will allow for more efficient swelling. It is preferable to keep the stirring speed low enough to prevent foaming, even without adding an antifoaming agent.

[0133] The equipment and methods used for stirring are not particularly limited, and known methods can be used. Specifically, examples include devices equipped with a motor with stirring blades that can stir the washing liquid in a container, devices equipped with an ultrasonic generator, devices that can shake the container, wet crushers, methods of stirring with water flow using a water pump, and bubbling methods using inert gases such as nitrogen gas.

[0134] The immersion time in the desorption solution depends on the structure of the laminate, but is generally in the range of 2 minutes to 48 hours. In the laminate, it is not necessary for the coating, such as the printed layer, to be 100% completely detached from the substrate, but it is preferable that 60% or more of the coating is detached out of 100% by mass, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more.

[0135] In the desorption process, the film substrate may be immersed in the desorption solution once or in several stages. That is, the film substrate may be recovered after one immersion, or it may be recovered after several immersions. Furthermore, if multiple immersions are performed in the desorption process, the concentration of the desorption solution may be changed. In addition, known processes such as washing with water or drying may be added as appropriate during the desorption process.

[0136] Furthermore, the desorption treatment liquid promotes the desorption of the plastic substrate by coming into contact with the edges of the printed material or laminate, the printed layer, the primer layer, or the interface between the substrate and other layers. For this reason, it is preferable that the printed layer, adhesive layer, or primer layer is exposed in the cross-section. For this reason, it is even more preferable that the laminate has been fragmented in advance by a crushing process.

[0137] It is preferable to include a step in which the recovered substrate is stirred in water or in the aforementioned delamination treatment solution after immersion in the aforementioned delamination treatment solution. This step increases the rate at which the coating, such as the printed layer, is detached from the substrate. The equipment and method of stirring are not particularly limited, and known methods can be used, but it is preferable to stir using a wet crusher.

[0138] Furthermore, it is preferable to perform a final wash by stirring the recovered substrate in the rinsing solution to remove any remaining detached materials such as ink and adhesive that have re-adhered to the substrate film that has separated into a single layer. Removing even small amounts of ink fragments remaining on the film surface significantly improves the quality of the recycled pellets. The equipment and methods for stirring in the rinsing solution are not particularly limited, and known methods can be used. Specifically, examples include devices equipped with a motor with stirring blades that can stir the cleaning solution in a container, devices equipped with a device that generates ultrasonic waves, devices that can shake the container, wet crushers, and kneaders.

[0139] (Recovery and reuse of the desorption treatment liquid) The desorption liquid used in the desorption process is fed into one or more recycling machines selected from filters, centrifugal separators, and ultrafilters to recover it, and after removing solid material, it can be reused. Water, rinsing liquid, etc., can also be reused in the same way. It is also possible to continuously operate the reuse processes for water, desorption liquid, rinsing liquid, etc., while wet crushing is being performed, separating solid material from water, washing liquid, and rinsing liquid.

[0140] (Drying of plastic separation) The separated and recovered laminate fragments and packaging material fragments are dried to remove residual moisture by one or more methods selected from vacuum heating drying, hot air drying, and pressure compression drying. As a pretreatment for producing the recycled pellets described later, briquettes may be produced after or during the drying of the recovered film fragments using a pressure compressor such as a press dewatering machine manufactured by Nippon Seam Co., Ltd., a pellet mill manufactured by Oike Iron Works Co., Ltd., or an Elcom Stella or briquette machine. If the base film is crushed into a powder using a grinder as a wet crusher, the crushed material is crushed to about 10 to 500 μm, and since the density of the crushed material is high, the pressure compression process can be omitted. The density varies depending on the materials that make up the crushed material, but a higher density is preferable because it is easier to handle when put into a kneader. Specifically, a dry weight of 0.03 kg or more is preferred, 0.05 kg or more is more preferred, 0.2 kg or more is even more preferred, and 0.3 kg or more is even more preferred.

[0141] (Melting and mixing) As described above, a separation and desorption process is performed as needed, and the crushed and dried laminate pieces and packaging material pieces are melted and kneaded. An example of a melting and kneading machine is a machine equipped with a cylinder in which a screw is arranged inside and a heat source such as an electric heater. A discharge section may be provided at the tip of the cylinder, and a supply port such as a hopper may be provided in the cylinder for supplying material. In addition, in order to prevent foreign matter from being mixed into the pellets described later, it is preferable that a screen mesh is provided inside the cylinder on the tip side of the screw.

[0142] In the melting and mixing section, shear heat is generated from the material itself due to the shear action caused by the rotation of a screw located inside the cylinder and heating by an electric heater, etc., and the material is melted and mixed. The material melted and mixed in the melting and mixing section passes through a screen mesh, which is installed as needed, and is discharged from the discharge section. The discharge section may be equipped with a die having a predetermined shape. The material discharged from the discharge section solidifies or loses its fluidity upon cooling and becomes recycled plastic.

[0143] The screw configuration is not particularly limited. For example, it may have known structures such as a single-screw extruder, a twin-screw extruder, and a rotor-type twin-screw kneader. In one embodiment, the screw diameter is 15 to 400 mm, preferably 50 to 300 mm, and more preferably 100 to 250 mm. In one embodiment, the effective screw length (L / D) is 15 to 150, preferably 20 to 100, and more preferably 25 to 80. In the effective screw length (L / D), L represents the screw length and D represents the screw diameter.

[0144] In one embodiment, the screw compression ratio is 2 to 5, preferably 2.5 to 4.5, and more preferably 3.4 to 3.7. The screw compression ratio refers to the ratio (V1 / V2) of the volume per pitch of the screw groove near the material supply section of the recycled plastic (V1) to the volume per pitch of the screw groove near the discharge section (V2).

[0145] The materials used to construct the screw are not particularly limited, and known materials can be used. From the viewpoint of preventing foreign matter contamination due to wear, it is preferable that the screw be made of stainless steel. Furthermore, various processes can be applied to the surface of the screw. Examples include nitriding, quenching, and powder metal quenching. From the viewpoint of preventing wear, it is preferable to apply powder metal quenching. As a combination of the screw's constituent material and surface treatment, a form in which stainless steel is subjected to powder metal quenching is more preferable.

[0146] Screen meshes can be woven in various ways, such as plain weave, twill weave, plain tatami weave, and twill tatami, or they can be made of perforated metal. The size of the screen mesh is preferably 40 mesh or more, more preferably 80 mesh or more, and even more preferably 120 mesh or more, taking into account the pressure and clogging of the discharge section. In one embodiment, the size of the screen mesh is 250 mesh or less, preferably 200 mesh or less.

[0147] The melting temperature during melt mixing can be adjusted considering the glass transition temperature and melting temperature of the contained polyolefin resin, the shape during pelletization, and the pressure applied during the molding process. For example, it is 120°C to 280°C, preferably 160°C to 250°C. The rotation speed of the screw during mixing is, for example, 50 rpm to 1000 rpm, preferably 80 rpm to 800 rpm, and more preferably 100 to 500 rpm. The shear rate of the screw is, for example, 200 to 4000 / sec, preferably 300 to 3500 / sec, and more preferably 400 to 3000 / sec.

[0148] The filling rate of laminate pieces or packaging material pieces within the extruder is, for example, 50 to 100 volume percent, preferably 60 to 95 volume percent, and more preferably 70 to 90 volume percent, relative to the void volume within the extruder. The void volume within the extruder refers to the cylinder volume minus the screw volume.

[0149] (Pelletization) After the laminate pieces and packaging material pieces are melted and kneaded, they are extruded from the extruder, cooled, and shredded to become recycled plastic pellets. The resin pressure at the tip discharge section of the extruder (hereinafter also referred to as discharge pressure) is preferably 50 MPa or less, more preferably 40 MPa or less, and even more preferably 30 MPa or less. In one embodiment, the resin discharge pressure at the tip discharge section is 0.01 MPa or more, preferably 0.1 MPa or more, and more preferably 0.5 MPa or more.

[0150] Examples of pelletizing methods include hot-cutting and strand-cutting methods, but are not particularly limited. Examples of cooling methods include air cooling, wind cooling, and water cooling. In the present invention, it is preferable to include a water cooling step. For example, it is preferable to cool to 20°C to 80°C, and more preferably to 30°C to 60°C.

[0151] (Additives, etc.) Recycled plastics may contain known additives. Components such as antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, antiblocking agents, mold release agents, UV absorbers, colorants, and biodegradability-enhancing agents can be added to the extent that they do not impair the purpose of the present invention, and are not particularly limited; commercially available products can also be used.

[0152] The recycled plastic may, in addition to the laminates and packaging materials mentioned above, contain petroleum or biomass-derived olefin resins, so-called virgin plastics, as raw materials. It is preferable that the petroleum or biomass-derived olefin resin added is of the same resin type as the first resin layer and second resin layer used in the plastic laminate, and it is preferable to appropriately select a recycled plastic in which the polyolefin resin content is 80% by mass or more, which is a characteristic of the present invention. Specifically, it is preferable that the resin mixture used for pelletizing contains 0.1 to 99% by mass of the recycled plastic and 99.9 to 1% by mass of an olefin resin derived from petroleum or biomass, and it is even more preferable that the resin mixture used for pelletizing contains 20 to 80% by mass of the recycled plastic and 80 to 20% by mass of an olefin resin derived from petroleum or biomass.

[0153] The aforementioned additives and virgin plastics may be supplied to the melting and kneading machine at the same time as the recycled plastic pellets are produced, or they may be supplied at the same time as the recycled plastic pellets when producing the plastic film of the present invention, as described later.

[0154] (Method of manufacturing plastic film) As a method for obtaining a plastic film using the aforementioned recycled plastic as a raw material, any of the following methods can be used: the T-die method, the inflation method, or the calendering method.

[0155] (T-die method) Examples of T-die methods and co-extrusion T-die methods are described. The recycled plastic pellets, and optionally virgin plastic pellets and additives, are mixed in a predetermined ratio, dried, and then supplied to a known melt lamination extruder. In the manufacturing process of this invention, single-screw or twin-screw extruders can be used. Furthermore, to eliminate the pellet drying process, a vacuum line may be provided in the extruder, and a vented extruder can also be used. In addition, for layer B, where the extrusion volume is greatest, a so-called tandem extruder can be used, in which the function of melting the pellets and the function of maintaining the molten pellets at a constant temperature are divided between the extruders.

[0156] The resin, melted and extruded in the extruder, is filtered. Since even very small foreign particles can become large protrusion defects if they enter the film, it is effective to use a high-precision filter that can capture 95% or more of foreign particles, for example, that are 3 μm or larger. Next, the material is extruded into a sheet through a slit-shaped slit die and cooled and solidified on a casting roll to create an unstretched film. If the film has a single-layer structure, a single-layer manifold is used to extrude the sheet from the die. If a laminated structure, such as a three-layer laminated film, is obtained, three extruders and three manifolds or confluence blocks (e.g., confluence blocks with a rectangular confluence section) are used to laminate the material into three layers, and the sheet is extruded from the die (co-extrusion method). The co-extrusion method is preferable because it allows for relatively free adjustment of the thickness ratio of each layer, and it is hygienic and cost-effective in obtaining a multilayer film. On the other hand, when laminating resins with a large difference between their melting point and Tg, the appearance of the film may deteriorate or it may become difficult to form a uniform layer structure during co-extrusion. To suppress such deterioration, the T-die chill-roll method, which allows for melt extrusion at relatively high temperatures, is preferred.

[0157] The sheet extruded from the die is cooled on a casting roll to produce an unstretched film. When stretching the obtained unstretched film, the film, which has been cooled in close contact with the casting roll, is separated from the casting roll using a separation roll and guided to the next stretching process. The stretching method may be simultaneous biaxial stretching or sequential biaxial stretching. When manufacturing a film using sequential stretching, the initial longitudinal stretching is important for suppressing the occurrence of defects and thickness unevenness in the longitudinal direction, and the stretching temperature is 45°C to 180°C, preferably 80°C to 170°C. If the stretching temperature is lower than 45°C, the film is prone to tearing, and if the stretching temperature is higher than 180°C, the film surface is prone to thermal damage. Furthermore, from the viewpoint of preventing uneven stretching and scratches, it is preferable to perform stretching in two or more stages, with a total stretching ratio of 1.1 to 5.0 times, preferably 3.0 to 4.0 times, in the length direction, and 1.1 to 7.0 times, preferably 3.0 to 5.0 times, in the width direction. When setting the longitudinal stretching ratio to the aforementioned values, it is desirable to set multiple stretching sections to make it less likely for the stretching roll and film to slip, in order to suppress fluctuations in stretching tension due to slippage.

[0158] In sequential stretching, the longitudinal stretching process is prone to damage when the film slips due to the difference in peripheral speed between the roll and the film during contact between the film and the roll, and can also cause uneven thickness in the longitudinal direction. Therefore, a drive system that allows the peripheral speed of each roll to be set individually is preferred. In the longitudinal stretching process, the material of the transport roll is selected by either heating the unstretched film to above its glass transition point before stretching, or transporting it to the stretching zone while maintaining a temperature below the glass transition point and then heating it all at once during stretching. When heating the unstretched film to above its glass transition point before stretching, adhesion due to heating can induce uneven stretching. To prevent this, it is preferable to select from non-stick silicone rolls, ceramics, or Teflon®. Furthermore, the stretching roll is the step in the process where the film is subjected to the most stress, and is prone to stretching irregularities that cause scratches and thickness variations in the longitudinal direction. Therefore, the surface roughness Ra of the stretching roll is preferably 0.005 μm or more and 1.0 μm or less, and more preferably 0.1 μm or more and 0.6 μm or less. If Ra is greater than 1.0 μm, the irregularities on the roll surface during stretching are more likely to be transferred to the film surface, while if it is less than 0.005 μm, the roll and the film surface will adhere, making the film more susceptible to thermal damage. To control surface roughness, it is effective to appropriately adjust the particle size of the abrasive, the number of polishing cycles, etc.

[0159] In sequential stretching, setting the longitudinal stretching ratio lower than the transverse stretching ratio is a preferable stretching condition for reducing thickness unevenness in the longitudinal direction.

[0160] Next, the unstretched film is transported to the stretching zone while being kept at a temperature below the glass transition point. When heating the film all at once during stretching, it is preferable to use metal rolls with a surface roughness Ra of 0.2 μm to 0.6 μm, which have been surface-treated with hard chromium or tungsten carbide, for the transport rolls in the preheating zone, in order to suppress adhesion that can cause heat wrinkles.

[0161] Next, the uniaxially oriented film, which has been stretched in the longitudinal direction, is stretched in the width direction using a transverse stretcher to produce a biaxially oriented (biaxially oriented) film. This transverse stretcher uses self-circulation in each oven chamber to blow hot air onto the film, thereby raising the film's temperature and performing stretching and heat fixing. At this time, in order to prevent oligomers and volatile components precipitated from the heat-treated film in the oven from cooling and adhering to the oven, it is advisable to supply and exhaust air into the oven to replace the air. When the air supplied into the oven merges with the circulating air, if the air temperature remains close to that of the outside air, temperature unevenness may occur in the air after merging, potentially worsening the thickness unevenness in the longitudinal and width directions. Therefore, it is preferable to heat the supplied air to the same temperature as the circulating air, or to a temperature commensurate with the capacity of the heat exchanger that heats the circulating air.

[0162] The stretching process may involve re-stretching once or more in each direction, or simultaneous re-stretching in two axes. One method to suppress thickness unevenness in the longitudinal direction is to alleviate the bowing that occurred in the previous transverse stretching process during the longitudinal re-stretching process. In this case, the transport rolls may be heated before the longitudinal re-stretching, or unheated rolls may be used for transport. Furthermore, the film may pass through the longitudinal re-stretching process without applying a stretching ratio. After the longitudinal re-stretching, transverse stretching is performed, and the film is heat-treated after stretching. This heat treatment can be carried out in an oven, on heated rolls, or any other conventionally known method. The heat treatment temperature can usually be any temperature between 70°C and 180°C, and the heat treatment time is usually preferably between 1 second and 60 seconds. The heat treatment may be carried out while relaxing the film in its longitudinal and / or width directions.

[0163] After heat treatment, the film can be modified by providing, for example, an intermediate cooling zone or a slow cooling zone to adjust its dimensional change rate and flatness. In particular, to impart a specific thermal shrinkage property, the film may be relaxed in the longitudinal and / or transverse directions during or after the heat treatment in the intermediate cooling zone or slow cooling zone.

[0164] After biaxial stretching, the film is cooled in a conveying process, then the edges are cut and the film is wound to obtain an intermediate product. During this conveying process, the film thickness in the width direction is measured, and this data is used as feedback to adjust the film thickness by adjusting the die thickness, etc., and foreign matter can also be detected using a defect detector.

[0165] The thickness of the resulting film is preferably 5 to 300 μm, and more preferably 10 to 200 μm, when a single-layer film is obtained. Furthermore, when a film with a three-layer laminated structure is obtained by co-extrusion, for example, the thickness of each layer is preferably 1 to 200 μm, and more preferably 2 to 150 μm. The total film thickness is preferably 5 to 300 μm, and more preferably 10 to 200 μm.

[0166] (Inflation method) Let's describe an example of the inflation method. In the specifications and molding conditions of the inflation molding machine, for example, the diameter of the extruder is 10 to 600 mm, preferably 20 to 300 mm, and more preferably 25 to 200 mm, and the ratio L / D of the diameter D to the length L from the bottom of the hopper to the tip of the cylinder is 8 to 45, preferably 12 to 36.

[0167] The die has a shape commonly used in inflation molding, such as a spider type, spiral type, or stacking type flow path, and its diameter is 1 to 5000 mm, preferably 5 to 3000 mm, and more preferably 10 to 1800 mm. The bubble can be cooled using a commonly used air ring, and the cooling gas can be any known type. Furthermore, its temperature can be cooled by a chiller or heated by a heater. In addition, known methods can be used to cool the bubble, such as blowing cooling air from an external air ring or circulating cooling gas inside. The shape and number of air rings are not limited, and one or more of known types, such as single-slit, dual-slit, or chambered types, can be provided.

[0168] The molding conditions are as follows: the resin extruded from the die has a temperature in the range of 140 to 270°C, preferably 180 to 250°C; the average extrusion rate, determined by the extrusion rate and die shape, is 1 mm / min to 10 m / min, preferably 5 mm / min to 5 m / min, and more preferably 10 mm / min to 1 m / min. The bubbles exiting the die are expanded by the internal gas, and the blow ratio, expressed as the ratio of the bubble diameter to the die bore diameter, is in the range of 1.0 to 4.5, preferably 1.5 to 3.5; and the TUR, expressed as the ratio of the take-up rate to the average flow velocity when extruded from the die, is in the range of 2.0 to 200, preferably 10 to 100. These bubbles are cooled and solidified, and the frost line height from the die exit to the solidification of the bubbles varies depending on the film formation rate and film thickness, but is in the range of 5 to 1800 mm, preferably 10 to 1200 mm, and more preferably 20 to 800 mm. The thickness of the resulting film is preferably 5 to 300 μm, and more preferably 10 to 200 μm, when a single-layer film is obtained. Furthermore, when a film with a three-layer laminated structure is obtained by co-extrusion, for example, the thickness of each layer is preferably 1 to 200 μm, and more preferably 2 to 150 μm. The total film thickness is preferably 5 to 300 μm, and more preferably 10 to 200 μm.

[0169] When pre-kneading is necessary to obtain the sheet or film of the present invention, known apparatus commonly used for thermoplastic resins can be used.

[0170] (calendering method) This section describes the calendering method. The preferred temperature setting for the calendering apparatus during molding is 80 to 180°C, and more preferably 90 to 170°C. If the temperature is below 80°C, the sheet may harden during processing, resulting in no sheet being obtained, or even if a sheet is obtained, it may have many flow marks and bank marks, resulting in an inferior appearance. On the other hand, if the temperature exceeds 180°C, the viscosity during melting is low and the fluidity is high, which may make processing difficult and may also cause thermal degradation.

[0171] The rotation speed of the calender roll is preferably 5 to 60 m / min, and more preferably 10 to 50 m / min. If the calender roll rotation speed is less than 5 m / min, air in the molten material will not escape easily, resulting in defects on the sheet or film surface. Also, if the calender roll rotation speed is faster than 60 m / min, the material may not be able to be picked up.

[0172] After biaxial stretching deformation of recycled plastic using a calendering or roll forming apparatus, further thin sheets or films can be efficiently produced by melt-stretching in at least one direction in the next step. Here, melt-stretching refers to stretching the recycled plastic while it is molten. The stretching ratio when melt-stretching is preferably 120-500%, more preferably 130-400%, and even more preferably 150-350%. If a sheet or film is produced with a stretching ratio of less than 120%, the improvement in production efficiency due to melt-stretching is minimal, and if a sheet or film is produced with a stretching ratio of 500% or more, stretching unevenness may occur, making it difficult to obtain a sheet or film of uniform thickness. Here, the stretching ratio when melt-stretching refers to 100 × [thickness of the sheet or film before melt-stretching] / [thickness of the sheet or film after melt-stretching].

[0173] The resulting plastic film is preferably obtained by biaxial stretching deformation of recycled plastic, melt stretching as needed, and then cooling it in contact with a drum or the like. The set temperature of the cooling drum is preferably 0 to 120°C, more preferably 20 to 100°C. At temperatures higher than 120°C, cooling is insufficient, making post-molding take-up difficult, and the resulting plastic film may deform. Also, temperatures lower than 0°C are not economical because they require refrigerants.

[0174] The thickness of the resulting plastic film is not particularly limited, but is preferably less than 1.0 mm, more preferably 0.50 mm or less, and even more preferably 0.30 mm or less. If the thickness of the sheet or film is 1 mm or more, the surface smoothness of the sheet or film may be poor. When obtaining a sheet or film with a thickness of 1.0 mm or more, it is preferable to manufacture it by laminating multiple sheets or films with a thickness of less than 1.00 mm. On the other hand, the lower limit of the thickness depends on the molding apparatus, but considering processability and thickness uniformity, it is preferably 0.03 mm or more, and more preferably 0.05 mm or more.

[0175] By combining the above methods, it is possible to obtain a plastic film having, for example, the following laminated structure. (1) A plastic film having at least two resin layers (A) and (B) made from recycled plastic. In this case, it is preferable that the process includes the steps of heating and melting each of the resin mixture (A) containing 0.1 to 99% by mass of recycled plastic and 99.9 to 1% by mass of olefin resin derived from petroleum or biomass, and the resin mixture (B) in an extruder, laminating them in the order of (A) / (B) in the molten state, and forming a film using one of the T-die method, inflation method, or calendering method, and it is preferable to use the co-extrusion method in the lamination step.

[0176] (2) A plastic film having at least a resin layer (A), a resin layer (B), and a resin (C) made from recycled plastic. In this case, it is preferable to have a step of heating and melting each of the resin mixture (A), resin mixture (B), and resin mixture (C) in a separate extruder, each containing 0.1 to 99% by mass of recycled plastic and 99.9 to 1% by mass of olefin resin derived from petroleum or biomass, in a resin mixture (A), a resin mixture (B), and a resin mixture (C), in and forming a film using one of the T-die method, inflation method, or calendering method, and it is preferable to use the co-extrusion method in the lamination step. Furthermore, in the process of stacking (A), (B), and (C) in a molten state, the stacking order is not particularly limited; they may be stacked in the order of (A) / (B) / (C), (A) / (C) / (B), (B) / (A) / (C), or (B) / (C) / (A).

[0177] The resin mixture (B) and the resin mixture (C) may consist solely of olefin resins derived from petroleum or biomass, or they may contain olefin resins derived from petroleum or biomass and the recycled plastic. In the case of a resin mixture containing olefin resins derived from petroleum or biomass and the recycled plastic, it is preferable that the recycled plastic is present in an amount of 0.1 to 99% by mass and the olefin resin derived from petroleum or biomass is present in an amount of 99.9 to 1% by mass.

[0178] Furthermore, the resin mixture (B) and the resin mixture (C) may contain known additives. Components such as antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, antiblocking agents, mold release agents, ultraviolet absorbers, colorants, and biodegradability-granting agents can be added to the extent that they do not impair the purpose of the present invention, and are not particularly limited; commercially available products can also be used.

[0179] In the plastic film having at least a resin layer (A), a resin layer (B), and a resin (C) made from recycled plastic as raw material, it is preferable that the resulting plastic film has better film properties by placing at least the resin layer (A), made from recycled plastic as raw material, on the inside of the laminated structure. The plastic film of the present invention is a practical film that is less likely to be perforated or torn during the series of processes in film molding, but in applications where higher strength is desired during distribution, such as lid material, a plastic film with even greater strength can be obtained if the outermost layer structure during distribution is a resin mixture (B) or resin mixture (C) made from olefin resin derived from petroleum or biomass.

[0180] Specifically, a resin mixture (B) consisting of olefin resin derived from petroleum or biomass / a resin mixture (A) containing 0.1 to 99% by mass of the recycled plastic and 99.9 to 1% by mass of olefin resin derived from petroleum or biomass / a resin mixture (C) consisting of olefin resin derived from petroleum or biomass, Alternatively, it is preferable that the resin mixture (B) contains 0.1 to 99% by mass of the recycled plastic and 99.9 to 1% by mass of an olefin resin derived from petroleum or biomass; (A) contains 0.1 to 99% by mass of the recycled plastic and 99.9 to 1% by mass of an olefin resin derived from petroleum or biomass; or (C) is a resin mixture consisting of an olefin resin derived from petroleum or biomass.

[0181] The resulting plastic film surface may be subjected to various surface treatments, such as flame treatment or corona discharge treatment, as necessary, to ensure that an adhesive layer free from defects such as film breakage or repulsion is formed.

[0182] Since the plastic film of the present invention is obtained as a substantially unstretched multilayer film by the above manufacturing method, secondary molding such as deep drawing by vacuum forming and embossing is also possible. Furthermore, embossing may be performed immediately after molding by contacting the film with a roll having an uneven surface.

[0183] (Laminates, packaging materials) The plastic film of the present invention can be laminated by laminating it with a separate base film or by other means to form a laminate.

[0184] The structure of the aforementioned laminate is as follows: (1) Substrate film / Adhesive layer / Plastic film of the present invention (2) Substrate film / Adhesive layer / Printed layer / Plastic film of the present invention (3) Substrate film / Adhesive layer / Second substrate / Printing layer / Adhesive layer / Plastic film of the present invention (4) Substrate film / Adhesive layer / First printing layer / Second printing layer / Plastic film of the present invention (5) Substrate film / Adhesive layer / Barrier layer / Adhesive layer / Plastic film of the present invention (6) Substrate film / Adhesive layer / Barrier layer / Printing layer / Adhesive layer / Plastic film of the present invention (7) Substrate film / Printing layer / Adhesive layer / Plastic film of the present invention (8) Substrate film / First printing layer / Second printing layer / Adhesive layer / Plastic film of the present invention (9) Substrate film / Printing layer / Adhesive layer / Barrier layer / Adhesive layer / Plastic film of the present invention Examples include, but are not limited to, additional base materials may be included.

[0185] If the plastic film of the present invention is made of a laminate with a similar structure to the laminate used in the recycled plastic that is the raw material of the present invention, it will be able to withstand repeated recycling.

[0186] On the other hand, a laminate tailored to the desired application may also be used. For example, the second and additional substrates may be unstretched resin films, stretched resin films, metal-deposited films such as unstretched metal-deposited films or stretched metal-deposited films, transparent metal-deposited films, or papers such as coated paper or fine paper, and are not particularly limited. Furthermore, the multiple adhesive layers may have the same composition or different compositions. Furthermore, to improve the adhesive strength of the adhesive layer, an anchor coat layer may be sandwiched between the layers.

[0187] The method for laminating the plastic film and the base film of the present invention is not particularly limited, and composite lamination technologies such as dry lamination, wet lamination, non-solvent lamination, extrusion lamination, sand lamination, and heat lamination may be used. The base film used can be the same as the first resin layer used in recycled plastics, as described above, which is preferable as it allows for the creation of laminates and packaging materials that can withstand repeated recycling.

[0188] Furthermore, the adhesive layer and printed layer in the laminate can be the same adhesive and printing ink used in the adhesive layer and / or printed layer used in recycled plastics, as described above, which is preferable as it allows for obtaining laminates and packaging materials that can withstand repeated recycling.

[0189] Furthermore, the substrate to be laminated to the plastic film of the present invention may be a substrate having a vapor-deposited layer made of inorganic material and / or inorganic oxide provided on the resin film described above. By using a substrate provided with the vapor-deposited layer, barrier properties can be imparted to the plastic laminate and the packaging material using the plastic laminate. The vapor-deposited layer can be formed using known inorganic materials or inorganic oxides by known methods, and its composition and formation method are not particularly limited. Furthermore, the laminate film made of the plastic film of the present invention may have two or more vapor-deposited films, which may have the same composition or different compositions.

[0190] As the above-mentioned vapor-deposited layer, for example, a vapor-deposited film of an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y) can be used. Furthermore, vapor-deposited films of inorganic oxides such as silicon oxide and aluminum oxide are transparent.

[0191] The inorganic oxides mentioned above are denoted as MOx (where M represents an inorganic element), such as SiOx and AlOx. The value of x can take on the following ranges: silicon (Si) 0-2, aluminum (Al) 0-1.5, magnesium (Mg) 0-1, calcium (Ca) 0-1, potassium (K) 0-0.5, tin (Sn) 0-2, sodium (Na) 0-0.5, boron (B) 0-1.5, titanium (Ti) 0-2, lead (Pb) 0-1, zirconium (Zr) 0-2, and yttrium (Y) 0-1.5. In the above, when x=0, it represents a completely inorganic element (pure substance), which is not transparent, and when the value of x is at the upper limit of the range, it indicates that it is completely oxidized. Silicon (Si) and aluminum (Al) are preferably used as the vapor-deposited layer. For silicon (Si), x values ​​in the range of 1.0 to 2.0 can be used, and for aluminum (Al), x values ​​in the range of 0.5 to 1.5 can be used.

[0192] The above-mentioned vapor-deposited layer can be formed on the surface of the substrate or the like by methods such as physical vapor deposition (PVD), including vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD), including plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition.

[0193] The thickness of the above-mentioned vapor-deposited layer is not particularly limited as long as the vapor-deposited layer alone can exhibit a certain level of gas barrier function. The preferred thickness range varies depending on the type of metal or metal oxide being deposited, but is preferably 0.05 to 70 nm, more preferably 0.1 to 70 nm, even more preferably 3 to 70 nm, and even more preferably 5 to 60 nm.

[0194] As the above-mentioned metal-deposited film, VM-CPP film, which is obtained by depositing a metal such as aluminum onto a CPP film, and VM-OPP film, which is obtained by depositing a metal such as aluminum onto an OPP film, can be used. Furthermore, examples of the transparent vapor-deposited films mentioned above include films obtained by vapor-depositing silica or alumina onto OPP film, PET film, nylon film, etc. A film with a coating applied to the vapor-deposited layer may be used for purposes such as protecting the inorganic vapor-deposited layer of silica or alumina.

[0195] Furthermore, for applications where transparency is not required, aluminum foil can be used alone or in combination as a barrier layer.

[0196] Paper can also be used as the base material mentioned above. For example, paper such as coated cardboard, cardstock, ivory paper, Manila cardboard, milk carton paper, cup paper, fine paper, kraft paper, pure white roll paper, glassine paper, parchment paper, Manila cardboard, white cardboard, coated paper, art paper, imitation paper, thin paper, thick paper, polyethylene coated paper, various synthetic papers, and acid-resistant paper can be used for printing on packaging materials for cosmetics, beverages, pharmaceuticals, toys, equipment, etc.

[0197] By using materials with gas barrier properties as the adhesive or anchor coating agent described later, a laminate film with particularly excellent barrier properties can be obtained. Particularly preferred as an adhesive with excellent gas barrier properties is 3 g / m². 2 The oxygen barrier property of the cured coating film of the adhesive applied with (solid content) is 300 cc / m². 2 Water vapor barrier capacity of 120 g / m² or less per day atm, or 120 g / m². 2This refers to a value of / day or less that satisfies at least one of the following conditions. Commercially available products include the "PASLIM" series, such as PASLIM VM001 and PASLIM J350X from DIC Corporation, and "Maxive" from Mitsubishi Gas Chemical Company.

[0198] Furthermore, the adhesive layer may also be formed from a thermoplastic resin, and it can be formed by conventionally known methods, such as the melt extrusion lamination method or the sand lamination method. When the adhesive layer is laminated by the extrusion lamination method, an anchor coat layer may be provided on the surface of the layer to be laminated by applying an anchor coat agent and drying it. When obtaining a plastic laminate or packaging material using the plastic laminate by laminating the plastic film of the present invention with a substrate using an extrusion lamination method or a sand lamination method, the nip roll or chill roll used during lamination may be replaced with an embossing roll to apply embossing to the surface on the sealing layer side.

[0199] (packaging material) The applications of the plastic film or laminate of the present invention are not particularly limited, but it can be used as packaging material for food, pharmaceuticals, industrial parts, general merchandise, magazines, etc., and is particularly suitable for use as lid material for packaging containers.

[0200] Preferably, the packaging bag described above is a packaging bag formed by overlapping and sealing the sealing layers of the plastic film or laminate of the present invention, or by overlapping and sealing the outermost layer and a sealing layer. For example, two sheets of the plastic film can be cut to the desired size of a packaging bag, overlapped and sealed on three sides to form a bag, and then the contents can be filled from the unsealed side and sealed to create a sealed packaging bag. Furthermore, it is also possible to form a packaging bag by sealing the ends of a roll of film into a cylindrical shape using an automatic packaging machine, and then sealing the top and bottom.

[0201] Furthermore, the plastic film or laminate of the present invention can also be used to form packaging bags and containers by overlapping and sealing another sealable film. In this case, the other film can be a film with relatively low mechanical strength, such as LDPE or EVA. Alternatively, a laminate film can be used, which is made by bonding a film such as LDPE or EVA to a stretched film with relatively good tear resistance, such as biaxially oriented polyethylene terephthalate film (OPET) or biaxially oriented polypropylene film (OPP).

[0202] (Sealing method) The plastic film or laminate of the present invention has sealing properties and can form a package by sealing. The sealing strength of the plastic film or laminate of the present invention may be adjusted as appropriate depending on the intended use. Furthermore, the plastic film of the present invention can be sealed not only by heat sealing but also by ultrasonic sealing. There are no particular limitations on the method of ultrasonic sealing, and known ultrasonic sealing methods or methods using known ultrasonic sealing devices can be appropriately selected depending on the purpose.

[0203] In packaging materials using the plastic film or laminate of the present invention, it is preferable to form arbitrary tear-initiating sections such as V-notches, I-notches, perforations, or micropores in the sealing portion in order to weaken the initial tear strength and improve ease of opening.

[0204] The contents to be filled into the packaging material of the present invention include, for example, food products such as rice crackers, bean snacks, nuts, biscuits / cookies, wafers, marshmallows, pies, semi-fresh cakes, candies, and snack foods; staples such as bread, instant noodles, dried noodles, pasta, aseptically packaged rice, rice porridge, packaged mochi, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, enoki mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potato products; and processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef. Examples of processed seafood products include fish ham and sausage, processed seafood products, kamaboko, seaweed, tsukudani, katsuobushi, salted seafood, smoked salmon, spicy cod roe, and other processed seafood products; fruits such as peaches, oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; frozen and chilled prepared foods such as hamburgers, meatballs, fried seafood, dumplings, and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; liquid seasonings; retort curry; and pet food.

[0205] Furthermore, as a non-food product, it can be used as a packaging material for various items such as cigarettes, disposable hand warmers, pharmaceuticals such as intravenous fluid packs, liquid laundry detergent, liquid dish soap, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotions and emulsions, vacuum insulation materials, and batteries.

[0206] (Molded body) The plastic film of the present invention can also be used as a molded body obtained by vacuum forming. The vacuum forming method is not particularly limited, and the following methods can be used, but are not limited thereto. • Heated pressure air molding method: A method in which battery packaging material is sandwiched between a lower mold having holes for supplying high-temperature, high-pressure air and an upper mold having a pocket-shaped recess, and the recess is formed by supplying air while heating and softening the material. • Preheater flat plate compressed air molding method: A method in which battery packaging material is heated and softened, then sandwiched between a lower mold having holes for supplying high-pressure air and an upper mold having pocket-shaped recesses, and the recesses are formed by supplying air. • Drum-type vacuum forming method: A method in which battery packaging material is partially heated and softened in a heated drum, and then the recesses of a drum having pocket-shaped recesses are vacuumed to form the recesses. • Pin molding method: A method in which the bottom material sheet is heated and softened, and then pressed into place using a mold with pocket-shaped indentations and recesses. • Preheater plug-assisted compressed air molding method: A method in which battery packaging material is heated and softened, then sandwiched between a lower mold having holes for supplying high-pressure air and an upper mold having a pocket-shaped recess, and the recess is formed by supplying air, and a convex-shaped plug is raised and lowered during molding to assist the molding process.

[0207] The surface temperature of the plastic film during vacuum forming is typically in the range of 150 to 250°C, but preferably in the range of 160 to 220°C, and more preferably in the range of 160 to 200°C. When the surface temperature is within the above range, the drawdown properties and shapeability are good, and the wall thickness becomes uniform.

[0208] The plastic film of the present invention can also be recycled by the above method and used as recycled plastic. [Examples]

[0209] The present invention will be described in more detail below with reference to specific synthesis examples and embodiments, but the present invention is not limited to these embodiments. In the following examples, "parts" and "%" represent "parts by mass" and "mass%", respectively, unless otherwise specified.

[0210] <Preparation of adhesive> (Preparation of adhesives 1-4) (Polyol composition 1) In a polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 105 parts terephthalic acid, 105 parts isophthalic acid, 53.83 parts dimer acid (Tsunodyme 216, manufactured by Tsukuno Oleochemicals Co., Ltd., AN=194 mgKOH / g), 103.26 parts adipic acid, 48.94 parts ethylene glycol, 98.12 parts neopentyl glycol, 48.94 parts 1,6-hexanediol, and 0.15 parts titanium tetraisopropoxide (hereinafter abbreviated as TIPT) were charged. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 240°C. When the acid value reached 1.5 mgKOH / g, the pressure was reduced to 10 mmHg or less and held for 1.5 hours to complete the esterification reaction and obtain an intermediate polyester polyol.

[0211] 100 parts of the intermediate polyester polyol, which had been heated to 100°C, were charged into a reactor equipped with a condenser and diluted and dissolved with 43 parts of ethyl acetate. Then, at 80°C, 3.2 parts of isophorone diisocyanate and 0.02 parts of iron neodecanoate were added, and the urethane reaction was carried out until the NCO content was 0.01% or less as measured by NCO. After that, the solution was further diluted with ethyl acetate until the non-volatile content was 50.0%, and a polyester urethane polyol solution with a Gardner viscosity of (WY) at this point was obtained. This was designated as polyol composition 1.

[0212] (Polyisocyanate composition 1) As polyisocyanate composition 1, a biuret form of hexamethylene diisocyanate (manufactured by Asahi Kasei Corporation, Duranate 24A-100, 100% non-volatile content) was used.

[0213] (Polyisocyanate composition 2) As polyisocyanate composition 2, a mixture of 40 parts of biuret hexamethylene diisocyanate (manufactured by Asahi Kasei Corporation, Duranate 24A-100, 100% non-volatile content), 40 parts of trimethylolpropane adduct toluene diisocyanate (manufactured by Covestro, Desmodule L75, 75% non-volatile content), and 20 parts of carbodiimide-modified diphenylmethane diisocyanate (manufactured by BASF INOAC Polyurethanes, Luplanate MM-103B, 100% non-volatile content) was used.

[0214] (Polyisocyanate composition 3) As the polyisocyanate composition 3, a trimethylolpropane adduct of toluene diisocyanate (manufactured by Covestro, Desmodule L75, non-volatile content 75%) was used.

[0215] (Polyisocyanate composition 4) As polyisocyanate composition 4, a mixture of 80 parts of xylene diisocyanate trimethylolpropane adduct (manufactured by Mitsui Chemicals, Inc., Takenate D-110N, non-volatile content 75%) and 20 parts of isophorone diisocyanate nurate (manufactured by Evonik Japan, Vestanate T-1890, non-volatile content 100%) was used.

[0216] (Adhesive 1) Adhesive 1 was prepared by blending polyol composition 1 and polyisocyanate composition 1 so that the [NCO] / [OH] ratio was 2.4. (Adhesive 2) Adhesive 1 was prepared by blending polyol composition 1 and polyisocyanate composition 2 so that the [NCO] / [OH] ratio was 2.0. (Adhesive 3) Adhesive 3 was prepared by blending polyol composition 1 and polyisocyanate composition 3 so that the [NCO] / [OH] ratio was 2.3. (Adhesive 4) Adhesive 4 was prepared by blending polyol composition 1 and polyisocyanate composition 4 so that the [NCO] / [OH] ratio was 1.8.

[0217] (Preparation of adhesives 5-7) (Polyol composition 2) In a polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, etc., 31.4 parts of diethylene glycol, 9.6 parts of glycerin, 19.9 parts of isophthalic acid, 39.1 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide were added, and an esterification reaction was carried out at an internal temperature of 220°C. After the dehydration reaction, a polyester polyol with an acid value of 1.5 mg KOH / g was obtained. 80 parts of this polyester polyol were added to 20 parts of polypropylene triol (AGC Excenol 430, molecular weight 400, trifunctional, hydroxyl value 400 mg KOH / g) to obtain polyol composition 2.

[0218] (Polyol composition 3) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 400 parts by mass of propylene glycol, 80 parts by mass of trimethylolpropane, 700 parts by mass of adipic acid, and 0.1 parts by mass of titanium tetraisopropoxide were charged under nitrogen gas introduction. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 250°C. The esterification reaction was terminated when the acid value fell to 1 mg KOH / g or less, yielding a polyester polyol. The hydroxyl value of the polyester polyol was 185 mg KOH / g. To this polyester polyol, 6% by mass of amine-initiated polypropylene polyol (ADEKA, EDP-450, molecular weight 450, hydroxyl value 505 mg KOH / g) was added to obtain polyol composition 3. The hydroxyl value of polyol composition 3 was 220 mg KOH / g.

[0219] (Polyisocyanate composition 5) 774.5 parts of toluene diisocyanate (TDI) were added to a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, and the mixture was heated to 40°C while stirring under a nitrogen gas stream. Then, 225.5 parts of bifunctional polyethylene glycol with a molecular weight of 200 were added carefully, taking care to avoid exothermic reactions, and the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphate was added to terminate the reaction. Next, using a thin-film distillation apparatus, the TDI in the urethane prepolymer, which was the reaction product of TDI, was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI content in the urethane prepolymer was 0.05% by mass of the solid content, thereby obtaining a polyurethane polyisocyanate with an NCO% of 14.5%.

[0220] Polyisocyanate composition 5 was prepared by mixing 90 parts of synthesized polyurethane polyisocyanate with 10 parts of hexamethylene diisocyanate nurate (manufactured by Covestro, Desmodulo N3300, 100% non-volatile content).

[0221] (Polyisocyanate composition 6) In a flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 7 parts ethylene glycol and 35 parts diethylene glycol were charged and heated to 80°C while stirring under a nitrogen gas stream. Further stirring was used to charge 36 parts adipic acid and 22 parts isophthalic acid into the reaction vessel. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, maintaining the internal temperature at 250°C, and the esterification reaction was carried out. When the acid value became 12.0 mg KOH / g or less, the temperature was raised to 240°C, and the pressure inside the reaction vessel was gradually reduced to 40 Torr or less to proceed with the reaction, yielding a polyester polyol with an acid value of 1.0 mg KOH / g and a hydroxyl value of 84 mg KOH / g, having hydroxyl groups at both ends.

[0222] In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 342.8 parts of toluene diisocyanate (TDI) were added and heated to 40°C while stirring under a nitrogen gas stream. Then, 657.2 parts of the polyester polyol synthesized above were added carefully, taking care to avoid exothermic reactions, and the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphate was added to terminate the reaction. Next, using a thin-film distillation apparatus, the TDI in the urethane prepolymer, which was the reaction product of TDI, was purified to 0.05% by mass of the solid content at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI content was 0.05% by mass of the solid content, thereby obtaining a polyurethane polyisocyanate with an NCO% of 4.8%.

[0223] Polyisocyanate composition 6 was prepared by mixing 90 parts of synthesized polyurethane polyisocyanate with 10 parts of hexamethylene diisocyanate nurate (manufactured by Covestro, Desmodulo N3300, 100% non-volatile content).

[0224] (Polyisocyanate composition 7) 582.2 parts of toluene diisocyanate (TDI) were added to a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, and heated to 40°C while stirring under a nitrogen gas stream. Then, 278.5 parts of bifunctional polyethylene glycol with a molecular weight of 400 and 139.3 parts of bifunctional polypropylene glycol with a molecular weight of 1000 were added, taking care to avoid exothermic reactions, and the mixture was then heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphate was added to terminate the reaction. Next, using a thin-film distillation apparatus, the TDI in the urethane prepolymer, which was the reaction product of TDI, was purified to 0.05% by mass of the solid content at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI content was 0.05% by mass of the solid content, thereby obtaining NCO% polyurethane polyisocyanate. This was designated as isocyanate composition 7.

[0225] (Adhesive 5) Adhesive 5 was prepared by mixing 2:70 parts of polyol composition and 5:100 parts of polyisocyanate composition. (Adhesive 6) Adhesive 6 was prepared by mixing 2:30 parts of polyol composition and 6:100 parts of polyisocyanate composition. (Adhesive 7) Adhesive 7 was prepared by mixing 3:100 parts of a polyol composition and 7:100 parts of a polyisocyanate composition.

[0226] (Preparation of adhesives 8-11) (Polyol composition 4) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 54.0 parts of 3-methylpentanediol, 46.0 parts of isophthalic acid, and 0.01 parts of titanium tetraisopropoxide were charged under nitrogen gas introduction. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 250°C. The esterification reaction was terminated when the acid value fell to 1 mg KOH / g or less, yielding a polyester polyol with a number average molecular weight of 500 and a hydroxyl value of 224.

[0227] Polyol composition 4 was prepared by mixing 30 parts of the polyester polyol synthesized above, 40 parts of polypropylene glycol (AGC Excenol 420, molecular weight 400, bifunctional, hydroxyl value 280 mg KOH / g), 10.9 parts of polypropylene triol (AGC Excenol 430, molecular weight 400, trifunctional, hydroxyl value 400 mg KOH / g), 17 parts of polyoxypropylene triamine (Huntsman Jeffamine T-403, molecular weight 440, amine value 355 mg KOH / g), 0.1 parts of dibutyltin dilaurelate, 1.0 part of 3-glycidoxypropyltrimethoxysilane, and 1.0 part of 3-aminopropyltriethoxysilane.

[0228] (Polyol composition 5) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 54.0 parts of 3-methylpentanediol, 30.0 parts of trimethylolpropane, 60.0 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide were charged under nitrogen gas introduction. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 220°C. The esterification reaction was terminated when the acid value fell to 1 mg KOH / g or less, yielding a polyester polyol with a number average molecular weight of 500 and a hydroxyl value of 337.

[0229] Polyol composition 5 was prepared by mixing 25 parts of the polyester polyol synthesized above, 13.66 parts of polypropylene triol (Actocol T-1000, manufactured by Mitsui Chemicals, molecular weight 1000, trifunctional), 40 parts of polypropylene glycol (Excenol 420, manufactured by AGC, molecular weight 400, bifunctional, hydroxyl value 280 mg KOH / g), 10 parts of polypropylene polyol (Sannix HD-402, manufactured by Sanyo Chemical Industries, molecular weight 600, tetrafunctional), 9 parts of polyoxypropylene triamine (Jeffermin T-403, manufactured by Huntsman, molecular weight 440, amine value 355 mg KOH / g), 0.9 parts of dimethylolpropionic acid, 0.94 parts of ε-caprolactam, and 0.5 parts of BicatZ.

[0230] (Polyisocyanate composition 8) 150 parts by mass of hexamethylene diisocyanate (HDI) was charged into a flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, stirred under nitrogen gas, and heated to 60°C. 100 parts by mass of polypropylene glycol with a number average molecular weight of 400 was added dropwise in several portions, and the mixture was stirred for 5-6 hours to complete the urethane formation reaction. Next, using a thin-film distillation apparatus, the HDI in the urethane prepolymer, which is the reaction product of HDI, was purified at a pressure of approximately 0.02 Torr and a temperature of 140°C until the HDI content in the solids was 1% by mass, thereby obtaining polyisocyanate composition 8 with an NCO group content of 9%.

[0231] (Polyisocyanate composition 9) In a flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, 40.2 parts of 4,4-diphenylmethane diisocyanate and 10.0 parts of hexamethylene diisocyanate nurate were charged into the reaction vessel and stirred under nitrogen gas, and heated to 60°C. To this flask, 37.9 parts of bifunctional polypropylene glycol with a number average molecular weight of 1000 and 2.0 parts of 2,2,4-trimethyl-1,3-pentanediol were added dropwise in several portions, and the mixture was stirred at 80°C for 5-6 hours to carry out the urethane reaction and obtain a polyisocyanate. The obtained polyisocyanate was mixed with 10.0 parts of carbodiimide-modified isocyanate to obtain polyisocyanate composition (X-1).

[0232] (Adhesive 8) Polyol composition 4 and polyisocyanate composition 8 were used in such a ratio that [NCO] / [OH] was 1.3. (Adhesive 9) Polyol composition 5 and polyisocyanate composition 8 were used in such a ratio that [NCO] / [OH] was 1.3. (Adhesive 10) Polyol composition 4 and polyisocyanate composition 9 were used in such a ratio that [NCO] / [OH] was 1.3. (Adhesive 11) Polyol composition 5 and polyisocyanate composition 9 were used in such a ratio that [NCO] / [OH] was 1.3.

[0233] (Preparation of adhesive 12) (Polyol composition 6) Into a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction pipe, a rectification pipe, a water separator, etc., 1223.3 parts of phthalic anhydride, 255.3 parts of ethylene glycol, 253.2 parts of glycerin, and titanium tetraisopropoxide were charged in an amount corresponding to 100 ppm based on the total amount of the polyvalent carboxylic acid and the polyvalent alcohol, and the mixture was gradually heated so that the temperature at the upper part of the rectification pipe did not exceed 100 °C, and the internal temperature was maintained at 220 °C. When the acid value reached 1 mg KOH / g or less, the esterification reaction was terminated, and a polyester polyol having a number average molecular weight of about 650, a hydroxyl value of 261.2 mg KOH / g, and an acid value of 0.8 mg KOH / g was obtained. This was used as polyol composition 6.

[0234] (Polyisocyanate composition 10) 143 parts of "Takenate D110N (NB)" manufactured by Mitsui Chemicals and 24.5 parts of "Takenate 500" manufactured by Mitsui Chemicals were mixed to prepare isocyanate composition 10.

[0235] (Adhesive 12) 70 parts of polyol composition 6, 167.5 parts of polyisocyanate composition 10, and 123 parts of ethyl acetate were stirred well to prepare adhesive 12.

[0236] <Manufacture of plastic laminate> (Plastic laminates 1a to 4a, 12a) To a uniaxially stretched polyethylene film with a thickness of 25 μm (hereinafter abbreviated as MDOPE film) (PE3K - BT), adhesive 1 was applied at 3.5 g / m 2 (Solid content), and after drying the solvent with a dryer, it was laminated with a linear low - density polyethylene film with a thickness of 60 μm (hereinafter abbreviated as LLDPE film) (TUX - MC - S). It was aged at 40 °C for 4 days to obtain plastic laminate 1a. Plastic laminates 2a to 4a, 12a were obtained in the same manner except that the adhesives used were changed to adhesives 2 to 4, 12.

[0237] (Plastic laminates 1b to 4b, 12b) An MDOPE film with a thickness of 25 μm was changed to a uniaxially stretched polyethylene film with a thickness of 25 μm printed with white ink "GLX-1012 White" (PVC-free gravure white ink manufactured by DIC Corporation) (hereinafter abbreviated as MDOPE film with a printing layer), and plastic laminates 1b to 4b and 12b were obtained in the same manner.

[0238] (Plastic laminates 5a to 7a) Adhesive 5 was applied to an MDOPE film (PE3K-BT) with a thickness of 25 μm at 2.0 g / m 2 (solid content), and laminated with an LLDPE film (TUX-MC-S) with a thickness of 60 μm. It was aged at 40°C for 2 days to obtain plastic laminate 5a. Plastic laminates 6a and 7a were obtained in the same manner except that the adhesives used were changed to adhesives 6 and 7.

[0239] (Plastic laminates 5b to 7b) Plastic laminates 5b to 7b were obtained in the same manner except that the MDOPE film with a thickness of 25 μm was changed to an MDOPE film with a printing layer.

[0240] (Plastic laminates 8a to 11a) Polyisocyanate composition 8 was applied to an MDOPE film (PE3K-BT) with a thickness of 25 μm, and polyol composition 4 was applied to an LLDPE film (TUX-MC-S) with a thickness of 60 μm, and the total coating amount of polyol composition 4 and polyisocyanate composition 8 was 1.7 g / m 2 Each was applied so that they were laminated together so that polyol composition 4 and polyisocyanate composition 8 came into contact. It was aged at 40°C for 2 days to obtain plastic laminate 8. Plastic laminates 9a to 11a were obtained in the same manner except that the adhesives used were changed to combinations of adhesives 9 to 11.

[0241] (Plastic laminates 8b to 11b) Plastic laminates 8b to 11b were obtained in the same manner, except that the MDOPE film with a thickness of 25 μm was replaced with an MDOPE film having a printed layer.

[0242] <Manufacturing of recycled plastics> The plastic laminate 1a was crushed using a crusher (DAS-20, manufactured by Daiko Seiki) to obtain a laminate pulverized material. In addition, a mixture of MDOPE film (PE3K-BT) with a thickness of 25 μm and LLDPE film (TUX-MC-S) with a thickness of 60 μm in a mass ratio of 30:70 was similarly pulverized in a pulverizer to obtain a virgin film pulverized mixture.

[0243] The laminated material and virgin film pulverized mixture were mixed in a 50:50 (mass ratio) and fed into the melting and kneading section of a twin-screw extruder (Kobe Steel KTX-30 twin-screw extruder). The melted and kneaded resin was extruded through a 100 μm filter, cooled by immersion in cold water, and then cut with a pelletizer to obtain recycled plastic pellets 1a. The extruder's screw rotation speed was set to 300 rpm, the temperature to 230 °C, the discharge rate to 8 kg / h, and the discharge pressure immediately after the start of extrusion was 1.3 to 2.2 MPa.

[0244] Recycled plastic pellets 2a-12a and 1b-12b were obtained in the same manner, except that plastic laminates 2a-12a and 1b-12b were used instead of plastic laminate 1a.

[0245] <Film Manufacturing> (Film manufacturing method: T-die method) Recycled plastic pellets 1a and DOWLWX2045G pellets (as virgin resin) were mixed in a 25:75 ratio and fed into the molten section of a T-die extruder (AIKI Riotec T-die film molding unit ALM-TMF200). The molten resin was extruded from the T-die and cooled and solidified with a cooling roll to obtain a 30 μm recycled film 1a. The extruder's screw rotation speed was set to 30 rpm and the temperature to 230°C. Recycled films 2a-12a and 1b-12b were obtained in the same manner, except that recycled plastic pellets 2a-12a and 1b-12b were used instead of recycled plastic pellet 1a.

[0246] (Film manufacturing method: Inflation method) Recycled plastic pellets 1a and DOWLWX2045G pellets were mixed in a 25:75 ratio and fed into the molten section of an inflation extruder (AIKI Riotec ALM-IMF30 inflation molding unit). The molten resin was extruded from the inflation die and cooled and solidified with air to obtain a recycled film with a thickness of 25 μm. The extruder's screw rotation speed was set to 38 rpm and the temperature to 230°C. Recycled films 2a-12a and 1b-12b were obtained in the same manner, except that recycled plastic pellets 2a-12a and 1b-12b were used instead of recycled plastic pellet 1a.

[0247] (Film manufacturing method: Calendering method) A 25μm recycled film was produced by mixing pellets of each type of recycled plastic with pellets of DOWLWX2045G in a ratio of 25:75 and forming the mixture at 180°C using a calendering machine (inverted L-type calendering machine manufactured by Nippon Roll Co., Ltd.). Recycled films 2a-12a and 1b-12b were obtained in the same manner, except that recycled plastic pellets 2a-12a and 1b-12b were used instead of recycled plastic pellet 1a.

[0248] (Film manufacturing method: Co-extrusion T-die method, 3 layers) A 25:75 mixture of recycled plastic pellets 1a and DOWLWX2045G pellets, and DOWLWX2045G pellets were each fed into the molten section using three extruders and three manifolds. The molten resin was extruded from a T-die and laminated into three layers: virgin olefin resin / 25:75 mixture of recycled plastic pellets and virgin olefin resin pellets / virgin olefin resin. The layers were then cooled and solidified using a cooling roll to produce recycled films with each layer having a thickness of 10 μm and a total thickness of 30 μm. Recycled films 2a-12a and 1b-12b were obtained in the same manner, except that recycled plastic pellets 2a-12a and 1b-12b were used instead of recycled plastic pellet 1a.

Claims

1. A method for manufacturing plastic films using recycled plastic as a raw material, The recycled plastic contains 80% by mass or more of polyolefin resin, and is obtained by crushing and melt-kneading a plastic laminate having at least a first resin layer, an adhesive layer and / or a printed layer, and a second resin layer. A method for manufacturing a plastic film, characterized by forming a film using one of the following methods: T-die method, inflation method, or calendering method.

2. The method for producing a plastic film according to claim 1, wherein the plastic laminate is crushed by wet crushing or dry crushing.

3. A method for producing a plastic film according to claim 1, comprising the steps of: heating and melting a resin mixture (A) containing 0.1 to 99% by mass of recycled plastic and 99.9 to 1% by mass of petroleum or biomass-derived olefin resin in an extruder; and forming a film using one of the T-die method, inflation method, or calendering method.

4. The aforementioned plastic film has at least a resin layer (A) and a resin layer (B) made from recycled plastic, A resin mixture (A) containing 0.1 to 99% by mass of the recycled plastic and 99.9 to 1% by mass of an olefin resin derived from petroleum or biomass, and a resin mixture (B) each of which are heated and melted in an extruder. A process of layering in the order of (A) / (B) in a molten state, A method for manufacturing a plastic film according to claim 1, comprising the step of forming a film by one of the following methods: T-die method, inflation method, or calendering method.

5. The aforementioned plastic film has at least a resin layer (A), a resin layer (B), and a resin layer (C) made from recycled plastic, A resin mixture (A) containing 0.1 to 99% by mass of recycled plastic and 99.9 to 1% by mass of olefin resin derived from petroleum or biomass, a resin mixture (B), and a resin mixture (C) each of which are heated and melted in separate extruders. A process of stacking (A), (B), and (C) in a molten state, A method for manufacturing a plastic film according to claim 1, comprising the step of forming a film by one of the following methods: T-die method, inflation method, or calendering method.

6. A method for manufacturing a laminate using a plastic film obtained by the manufacturing method described in any one of claims 1 to 5.

7. A method for producing a packaging material using a plastic film obtained by the manufacturing method described in any one of claims 1 to 5.

8. A method for manufacturing a lid material using a plastic film obtained by the manufacturing method described in any one of claims 1 to 5.