Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
  • C09J5/02—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers involving pretreatment of the surfaces to be joined
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/80—Packaging reuse or recycling, e.g. of multilayer packaging

Definitions

• the present invention relates to an adhesive, a laminate obtained using the adhesive, and a packaging material.
• Laminates used in various packaging materials, labels, etc. are given design, functionality, storage properties, convenience, and transportability by laminating a wide variety of substrates such as plastic films, metal foils, and paper, and in particular, packages made by molding such laminates into bags are used as packages for foods, medicines, detergents, etc.
• Two-component adhesives that combine a polyisocyanate composition and a polyol composition are widely known as adhesives used to bond these substrates together.
• Patent Documents 1 and 2 In recent years, there has been active research into recycling packaging materials made of such laminates. Generally, a method is known in which waste plastics that contain a mixture of thermoplastic resin and thermosetting resin are separated by specific gravity for recycling, but separation is difficult when the materials are stuck together with adhesive. For this reason, the use of an alkaline aqueous solution to peel off the laminates has been studied (Patent Documents 1 and 2).
• JP 2001-131484 A Japanese Patent Application Publication No. 11-209677
• the present invention has been made in consideration of these circumstances, and aims to provide a two-component curing adhesive that maintains its adhesive properties while exhibiting excellent release properties when immersed in an alkaline aqueous solution, as well as a laminate and packaging material obtained using the adhesive.
• the present invention relates to a two-component curing adhesive that includes an isocyanate composition (X) containing a polyisocyanate compound (A) and an isocyanate-reactive composition (Y) containing an active hydrogen group-containing compound (B),
• the active hydrogen group-containing compound (B) contains a hydroxyl group and an acid group, the average number of functional groups of the hydroxyl groups in the active hydrogen group-containing compound (B) is 1.5 or more and 3.0 or less, and the average number of functional groups of the acid groups in the active hydrogen group-containing compound (B) is 0.2 or more and 2.0 or less.
• the present invention further relates to a laminate including a first substrate, a second substrate, and an adhesive layer that bonds the first substrate and the second substrate, the adhesive layer being a cured coating film of the above-mentioned two-component curing adhesive, and a packaging material comprising the laminate.
• the adhesive of the present invention can provide a two-component curing adhesive that maintains its adhesive properties while exhibiting excellent releasability when immersed in an alkaline aqueous solution, as well as a laminate and packaging material that are excellent in both adhesive properties and releasability and are easily recyclable.
• the adhesive of the present invention is a two-component curing adhesive comprising an isocyanate composition (X) and an isocyanate-reactive composition (Y).
• the adhesive of the present invention will be described in detail below.
• the isocyanate composition (X) contains a polyisocyanate compound (A) having a plurality of isocyanate groups.
• the polyisocyanate compound (A) is not particularly limited, and examples thereof include aromatic diisocyanates, araliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and biuret, nurate, adduct, allophanate, carbodiimide-modified, and uretdione-modified products of these diisocyanates, and urethane prepolymers obtained by reacting these polyisocyanates with polyols, and these can be used alone or in combination.
• 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-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 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.
• polymethylene polyphenyl polyisocyanate
• Aromatic aliphatic diisocyanates refer to aliphatic isocyanates that have one or more aromatic rings in the molecule, and examples include, but are not limited to, m- or p-xylylene diisocyanate (also known as XDI), ⁇ , ⁇ , ⁇ ', ⁇ '-tetramethylxylylene diisocyanate (also known as TMXDI), etc.
• Aliphatic diisocyanates include, but are not limited to, 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.
• 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 dodecamethylene diisocyanate
• 2,4,4-trimethylhexamethylene diisocyanate 2,4,4-trimethylhexamethylene
• Alicyclic diisocyanates include, but are not limited to, 3-isocyanatomethyl-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), 1,4-bis(isocyanatomethyl)cyclohexane, etc.
• IPDI isophorone diisocyanate
• 1,3-cyclopentane diisocyanate 1,3-cyclohexane diisocyanate
• 1,4-cyclohexane diisocyanate 1,4-cyclohexane diisocyanate
• polyols used in the synthesis of the urethane prepolymer 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)cyclohexane, 2,2,4-trimethyl-1,3-pentanediol, and dimer diol; aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin
• Polyether polyols obtained by ring-opening polymerization of aliphatic diols and/or aliphatic polyols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;
• Lactone-based polyester polyols obtained by polycondensation reaction of aliphatic diols and/or aliphatic polyols with various lactones such as lactonoids and ⁇ -caprolactone; polyester polyols obtained by a polycondensation reaction between an aliphatic diol and/or an aliphatic polyol and a polycarboxylic acid;
• Bisphenols such as bisphenol A and bisphenol F
• alkylene oxide adducts include alkylene oxide adducts of bisphenol obtained by adding ethylene oxide, propylene oxide, etc. to bisphenols such as bisphenol A and bisphenol F. These may be used alone or in combination of two or more kinds.
• the polycarboxylic acids used in the synthesis of polyester polyols include aliphatic polycarboxylic acids such as malonic acid, ethylmalonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, succinic anhydride, alkenyl succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid, and trimer acid;
• aliphatic polycarboxylic acids such as malonic acid, ethylmalonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, succinic anhydride, alkenyl succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic
• Alkyl esters of aliphatic polycarboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;
• Alicyclic polycarboxylic acids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, himic anhydride, and HET anhydride;
• Aromatic polycarboxylic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride;
• Methyl esters of aromatic polycarboxylic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate; These can be used alone or in combination of two or more.
• the polyester polyol is a reaction product of a polycarboxylic acid and a polyhydric alcohol
• the polycarboxylic acid preferably contains at least one selected from an aliphatic polycarboxylic acid and an alkyl ester of an aliphatic polycarboxylic acid.
• the proportion of the at least one selected from an aliphatic polycarboxylic acid and an alkyl ester of an aliphatic polycarboxylic acid in the polycarboxylic acid can be appropriately adjusted, but is, for example, 20 mass% or more.
• the total amount of the polycarboxylic acid may be at least one selected from an aliphatic polycarboxylic acid and an alkyl ester of an aliphatic polycarboxylic acid.
• the polyol used in the synthesis of the urethane prepolymer preferably has a number average molecular weight of 200 or more and 3,000 or less.
• the number average molecular weight is a value measured by gel permeation chromatography (GPC) under the following conditions.
• Measuring device Tosoh Corporation HLC-8320GPC Column: TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1000HXL manufactured by Tosoh Corporation Detector: RI (differential refractometer)
• Data processing Multistation GPC-8020 model II manufactured by Tosoh Corporation Measurement conditions: Column temperature: 40°C Solvent: tetrahydrofuran Flow rate: 0.35 ml/min Standard: monodisperse polystyrene Sample: 100 ⁇ l of a tetrahydrofuran solution containing 0.2% by mass of resin solids filtered through a microfilter
• the equivalent ratio [NCO]/[OH] of the isocyanate groups and hydroxyl groups used in the reaction is in the range of 1.5 to 8.0, since this brings the viscosity of the adhesive into an appropriate range and improves the coatability.
• the polyisocyanate compound (A) preferably contains at least one selected from the group consisting of biuret, nurate, adduct, and allophanate forms of aliphatic diisocyanates, and urethane prepolymers of aromatic diisocyanates, and more preferably contains at least one selected from allophanate and biuret forms of aliphatic diisocyanates, and urethane prepolymers of aromatic diisocyanates.
• the proportion of these suitable polyisocyanate compounds in the polyisocyanate compound (A) can be adjusted as appropriate, and is, for example, 1 mass% or more.
• the entire amount of the polyisocyanate compound (A) may be these suitable polyisocyanate compounds.
• a preferred embodiment of the adhesive of the present invention is one in which the isocyanate composition (X) contains a bifunctional polyisocyanate compound (A), and the isocyanate-reactive composition (Y) described below contains an active hydrogen group-containing compound (B) having a hydroxyl value of 45 mgKOH/g or more and 300 mgKOH/g or less.
• the bifunctional polyisocyanate compound (A) it is preferable to use, for example, an allophanate of a diisocyanate or a urethane prepolymer of a diisocyanate and a diol.
• the amount of the bifunctional polyisocyanate compound (A) can be appropriately adjusted, and as an example, it is used in a range in which the molar ratio [NCO]/[OH] of the isocyanate group of the bifunctional polyisocyanate compound (A) to the hydroxyl group of the active hydrogen group-containing compound (B) is 0.8 to 3.0.
• a preferred embodiment of the adhesive of the present invention is one in which the isocyanate composition (X) contains a trifunctional or higher polyisocyanate compound (A), and the isocyanate-reactive composition (Y) described below contains an active hydrogen group-containing compound (B) having a hydroxyl value of 1 mgKOH/g or more and 60 mgKOH/g or less.
• the trifunctional or higher polyisocyanate compound (A) preferably contains, for example, a biuret of a diisocyanate or a urethane prepolymer of a diisocyanate and a trifunctional or higher polyol.
• the amount of the trifunctional polyisocyanate compound (A) can be appropriately adjusted, and as an example, it is used in a range in which the molar ratio [NCO]/[OH] of the isocyanate group of the trifunctional polyisocyanate compound (A) to the hydroxyl group of the active hydrogen group-containing compound (B) is 0.8 to 3.0.
• a preferred embodiment of the adhesive of the present invention is one in which the isocyanate composition (X) contains a prepolymer that is a reaction product of an aromatic diisocyanate and a polyol, and the isocyanate-reactive composition (Y) described below contains an active hydrogen group-containing compound (B) with a hydroxyl value of 1 mgKOH/g or more and 300 mgKOH/g or less.
• the amount of prepolymer blended can be adjusted as appropriate, and as an example, it is used in a range in which the molar ratio [NCO]/[OH] of the isocyanate groups in the prepolymer to the hydroxyl groups of the active hydrogen group-containing compound (B) is 0.8 to 3.0.
• the viscosity of the polyisocyanate composition (X) is adjusted to a range suitable for the non-solvent lamination method.
• the viscosity at 40°C is adjusted to be in the range of 500 to 5000 mPas, more preferably 500 to 3000 mPas.
• the viscosity of the polyisocyanate composition (X) can be adjusted, for example, by the amount of urethane prepolymer or the amount of low molecular weight isocyanate compound.
• the viscosity of the polyisocyanate composition (X) can be adjusted by an organic solvent, which will be described later.
• the isocyanate-reactive composition (Y) used in the adhesive of the present invention contains an active hydrogen group-containing compound (B).
• the active hydrogen group-containing compound (B) contains a hydroxyl group and an acid group.
• the average functionality of the hydroxyl group in the active hydrogen group-containing compound (B) is 1.5 or more and 3.0 or less, and the average functionality of the acid group in the active hydrogen group-containing compound (B) is 0.2 or more and 2.0 or less.
• Such an active hydrogen group-containing compound (B) is obtained, for example, by acid-modifying a polyol having an average functionality of 2.01 or more and 3.0 or less.
• the active hydrogen group-containing compound (B) is preferably obtained by acid-modifying a polyol having an average functionality of 2.01 or more and 3.0 or less.
• the average number of functional groups of the hydroxyl group of the active hydrogen group-containing compound (B) is calculated by the mole number of the hydroxyl group of the active hydrogen group-containing compound (B) / the mole number of the active hydrogen group-containing compound (B).
• the mole number of the hydroxyl group of the active hydrogen group-containing compound (B) is calculated from the hydroxyl value of the active hydrogen group-containing compound before acid modification (hereinafter referred to as the active hydrogen group-containing compound (b) for convenience) and the mole number of the acid group-containing compound used for modification.
• the mole number of the active hydrogen group-containing compound (B) is the mole number of the active hydrogen group-containing compound (b).
• the average functional number of the acid groups contained in the active hydrogen group-containing compound (B) is calculated in the same manner.
• the difunctional or trifunctional polyol compounds used in the preparation of the active hydrogen group-containing compound (B) include glycols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol;
• glycols such as ethylene glycol, 1,2-propanediol, 1,3-propanedio
• Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol
• Bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F
• Dimer diol dimer diol
• Polyether polyols 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 such as glycol or a trifunctional or tetrafunctional aliphatic alcohol;
• alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene
• a polymerization initiator such as glycol or a trifunctional or tetrafunctional aliphatic alcohol
• Polyester polyols (1) which are reaction products of polyesters obtained by ring-opening polymerization of cyclic ester compounds such as propiolactone, butyrolactone, ⁇ -caprolactone, ⁇ -valerolactone, ⁇ -methyl- ⁇ -valerolactone, etc., with polyhydric alcohols such as the above-mentioned glycols, glycerin, trimethylolpropane, pentaerythritol, etc.; Polyester polyol (2) obtained by reacting a difunctional polyol such as glycol, dimer diol, or bisphenol with a polycarboxylic acid: (3) a polyester polyol obtained by reacting a trifunctional or tetrafunctional aliphatic alcohol with a polycarboxylic acid; (4) a polyester polyol obtained by reacting a difunctional polyol with a trifunctional or tetrafunctional aliphatic alcohol and a polycarboxylic acid; Polyester polyols (5), which are poly
• a polyurethane polyol obtained by polymerizing at least one selected from a difunctional polyol, a trifunctional or a tetrafunctional aliphatic alcohol with an isocyanate compound
• Polyether urethane polyol (2) obtained by further increasing the molecular weight of a polyether polyol with an isocyanate compound
• Polyester polyurethane polyol (3) obtained by polymerizing the polyester polyols (1) to (5) with an isocyanate compound
• a polyester polyether polyurethane polyol (4) obtained by reacting at least one of the polyester polyols (1) to (5), a polyether polyol, and an isocyanate compound;
• Castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil, and 5-50 mole alkylene oxide adducts of castor oil, and mixtures of these, etc. are included.
• polyester polyols (1) to (5) can be the same as those exemplified as raw materials for the polyester polyols used in the synthesis of the above-mentioned urethane prepolymer.
• the acid group-containing compound used to modify these polyol compounds can be any compound having an acid group and a functional group capable of reacting with a hydroxyl group, without any particular limitations. More specifically, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, dodecenylsuccinic anhydride, polyadipic anhydride, polyazelaic anhydride, polysebacic anhydride, poly(ethyloctadecanedioic) anhydride, poly(phenylhexadecanedioic) anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhimic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexene dicarboxylic ...
• acid anhydrides examples include water, methylcyclohexene tetracarboxylic anhydride, ethylene glycol bistrimellitate dianhydride, HET acid anhydride, Nadic acid anhydride, methylnadic acid anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dianhydride, 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dianhydride, and compounds obtained by modifying these acid anhydrides with glycol.
• Glycols that can be used to modify the acid anhydride include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol; and polyether glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Furthermore, copolymer polyether glycols of two or more of these glycols and/or polyether glycols can also be used.
• the number average molecular weight of the active hydrogen group-containing compound (B) can be adjusted appropriately depending on the desired physical properties, but as an example, it is preferably 500 or more and 6000 or less.
• the adhesive of the present invention preferably contains an acid group-containing compound (C) such as a resin (C1) having an acid group or a low molecular weight compound (C2) having an acid group.
• an acid group-containing compound (C) such as a resin (C1) having an acid group or a low molecular weight compound (C2) having an acid group.
• ) is a compound having an acidic group and an acid value of 120 mgKOH/g or more and 350 mgKOH/g or less.
• the resin (C1) having an acidic group include resins having an acid value such as rosin-modified maleic acid resins and rosin-modified fumaric acid resins; acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and cinnamic acid.
• polymerizable monomers having an acidic group such as polymerizable monomers having a carboxyl group, such as acid anhydrides of these, polymerizable monomers having a sulfonic acid group, such as sulfonated styrene, and polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide, may be used.
• Radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-maleic anhydride resins, and terpene-maleic anhydride resins, which are copolymerized with polymerizable monomers having the above structure. and acid-modified polyolefin resins. These may be used singly or in combination.
• Low molecular weight compounds (C2) having an acidic group include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, margaric acid, and stearic acid; unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid; hydroxy acids such as lactic acid, malic acid, and citric acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and cinnamic acid; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid; tricarboxylic acids such as aconitic acid; oxocarbox
• the acid group-containing compound (C) preferably has at least one of a glass transition point, a softening point and a melting point of 100° C. or higher. It is also preferred that the acid group-containing compound (C) does not have a hydroxyl group.
• the use of the acid group-containing compound (C) is particularly useful in laminates described below, where there is a printed layer between the substrate and the cured coating (adhesive layer) of the adhesive of the present invention.
• the peeling of the printed layer from the substrate (deinking) and the peeling of the adhesive layer from the substrate or printed layer do not necessarily proceed simultaneously, but in the present invention, the adhesive contains the acid group-containing compound (C), which promotes deinking.
• the content of the acid group-containing compound (C) can be adjusted as appropriate, but as an example, it is 2 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the solid content of the active hydrogen group-containing compound (B).
• the viscosity of the polyisocyanate-reactive composition (Y) is adjusted to a range suitable for the non-solvent lamination method.
• the viscosity at 40°C is adjusted to be in the range of 100 to 5000 mPas, more preferably 500 to 3000 mPas.
• the viscosity of the polyisocyanate-reactive composition (Y) can be adjusted, for example, by the skeleton and number average molecular weight of the active hydrogen group-containing compound (B) and the plasticizer described below.
• the viscosity of the polyisocyanate-reactive composition (Y) can be adjusted by an organic solvent, which will be described later.
• the adhesive of the present invention may contain components other than those described above.
• the other component (D) may be contained in either or both of the isocyanate composition (X) and the isocyanate-reactive composition (Y), or may be prepared separately from these and mixed with the isocyanate composition (X) or the isocyanate-reactive composition (Y) immediately before application of the adhesive. Each component will be described below.
• Catalyst (D1) examples include metal catalysts, amine catalysts, and aliphatic cyclic amide compounds.
• Metal catalysts include metal complex, inorganic metal, and organic metal catalysts.
• Metal complex catalysts include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate.
• Inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, etc.
• Organometallic catalysts include organic zinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate; organic tin compounds such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organic nickel compounds such as nickel octylate and nickel naphthenate; organic cobalt compounds such as cobalt octylate and cobalt naphthenate; organic bismuth compounds such as bismuth octylate, bismuth neodecanoate, and bismuth naphthenate; and titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetra
• Amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxy
• Aliphatic cyclic amide compounds include ⁇ -valerolactam, ⁇ -caprolactam, ⁇ -enantholactam, ⁇ -capryllactam, and ⁇ -propiolactam. Among these, ⁇ -caprolactam is more effective at promoting hardening.
• Examples of the coupling agent (D2) include a silane coupling agent, a titanate-based coupling agent, and an aluminum-based coupling agent.
• Silane coupling agents include aminosilanes such as ⁇ -aminopropyltriethoxysilane, ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethoxysilane, N- ⁇ (aminoethyl)- ⁇ -aminopropyltrimethyldimethoxysilane, and N-phenyl- ⁇ -aminopropyltrimethoxysilane; epoxysilanes such as ⁇ -(3,4-epoxycyclohexyl)ethyltrimethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, and ⁇ -glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris( ⁇ -methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and ⁇ -methacryloxyprop
• Titanate coupling agents include, for example, tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.
• aluminum-based coupling agents examples include acetoalkoxyaluminum diisopropylate.
• the pigment (D3) is not particularly limited, and examples thereof include organic pigments and inorganic pigments such as extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, and pearlescent pigments, as well as plastic pigments, which are listed in the Paint Raw Materials Handbook 1970 Edition (compiled by the Japan Paint Manufacturers Association).
• extender pigments include precipitated barium sulfate, powdered gourd, precipitated calcium carbonate, calcium bicarbonate, kansui stone, white alumina, silica, finely powdered hydrous silica (white carbon), ultrafine anhydrous silica (aerosil), silica sand, talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and yellow earth.
• organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, Lake 4R, etc.; soluble azo pigments such as Lake C, Carmine 6B, Bordeaux 10, etc.; various (copper) phthalocyanine pigments such as Phthalocyanine Blue, Phthalocyanine Green, etc.; various chlorine dyeing lakes such as Rhodamine Lake, Methyl Violet Lake, etc.; various mordant dye pigments such as Quinoline Lake, Fast Sky Blue, etc.; various vat dye pigments such as Anthraquinone pigments, Thioindigo pigments, Perinone pigments, etc.; various quinacridone pigments such as Synchasia Red B, etc.; various dioxazine pigments such as Dioxazine Violet, etc.; various condensed azo pigments such as Chromophtal, etc.; aniline black, etc.
• insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, Lake 4R, etc.
• Inorganic pigments include various chromates such as yellow lead, zinc chromate, and molybdate orange; various ferrocyanide compounds such as Prussian blue; various metal oxides such as titanium oxide, zinc oxide, mapico yellow, iron oxide, red iron oxide, chrome oxide green, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; flake pigments of these metals, mica flake pigments; metallic pigments and pearl pigments such as mica flake pigments coated with metal oxides and micaceous iron oxide pigments; graphite, carbon black, etc.
• plastic pigments examples include "Grandol PP-1000" and “PP-2000S” manufactured by DIC Corporation.
• the pigment (D3) used may be appropriately selected depending on the purpose, but for example, it is preferable to use inorganic oxides such as titanium oxide and zinc oxide as white pigments, as they have excellent durability, weather resistance, and design properties, and it is preferable to use carbon black as a black pigment.
• the amount of pigment (D3) is, for example, 1 to 400 parts by mass per 100 parts by mass of the total solid content of the isocyanate composition (X) and the isocyanate-reactive composition (Y), and it is more preferable to use 10 to 300 parts by mass to improve adhesion and blocking resistance.
• plasticizer examples include phthalic acid plasticizers, fatty acid plasticizers, aromatic polycarboxylic acid plasticizers, phosphoric acid plasticizers, polyol plasticizers, epoxy plasticizers, polyester plasticizers, and carbonate plasticizers.
• phthalic acid plasticizers include phthalic acid ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, octyl decyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and di
• Fatty acid plasticizers include, for example, adipic acid plasticizers such as di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diglycol adipate; azelaic acid plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, and diisooctyl azelate; and di-n-butyl sebacate, di-( Sebacic acid plasticizers such as diisononyl sebacate and diisononyl sebacate; maleic acid plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate and di-(2-ethylhexyl) maleate; fumaric acid plastic
• aromatic polycarboxylic acid plasticizers include trimellitic acid plasticizers such as tri-n-hexyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, and triisodecyl trimellitate, and pyromellitic acid plasticizers such as tetra-(2-ethylhexyl) pyromellitate and tetra-n-octyl pyromellitate.
• Examples of phosphoric acid plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, cresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate, and tris(isopropylphenyl) phosphate.
• polyol-based plasticizers examples include glycol-based plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexoate), and dibutylmethylene bisthioglycolate, and glycerin-based plasticizers such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.
• glycol-based plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexoate), and dibutylmethylene bisthioglycolate
• glycerin-based plasticizers such as glycerol monoacetate, glycerol
• epoxy plasticizers include epoxidized soybean oil, epoxy butyl stearate, di-2-ethylhexyl epoxy hexahydrophthalate, diisodecyl epoxy hexahydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.
• polyester plasticizers examples include adipic acid polyesters, sebacic acid polyesters, and phthalic acid polyesters.
• Carbonate plasticizers include propylene carbonate and ethylene carbonate.
• plasticizers include partially hydrogenated terphenyls, adhesive plasticizers, and polymerizable plasticizers such as diallyl phthalate, acrylic monomers and oligomers. These plasticizers can be used alone or in combination of two or more.
• Examples of the phosphoric acid compound (D5) include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl)phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate.
• the adhesive of the present invention may be in the form of either a solvent-based or solventless type.
• the "solvent-based” adhesive in the present invention refers to a form used in a method in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating film, and then laminated to another substrate, that is, a so-called dry lamination method.
• Either or both of the isocyanate composition (X) and the isocyanate-reactive composition (Y) contain a highly soluble organic solvent capable of dissolving the components of the isocyanate composition (X) or the isocyanate-reactive composition (Y) used in the present invention.
• the organic solvent used as a reaction medium during the production of the components of the isocyanate composition (X) or the isocyanate-reactive composition (Y) may also be used as a diluent during coating.
• organic solvents having high solubility examples include esters such as ethyl acetate, butyl acetate, cellosolve acetate, etc., ketones such as acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, etc., ethers such as tetrahydrofuran, dioxane, etc., aromatic hydrocarbons such as toluene, xylene, etc., halogenated hydrocarbons such as methylene chloride, ethylene chloride, etc., dimethyl sulfoxide, dimethyl sulfamide, etc.
• esters such as ethyl acetate, butyl acetate, cellosolve acetate, etc.
• ketones such as acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, etc.
• ethers such as tetrahydrofuran, dio
• solvent-free adhesive refers to an adhesive form used in a method in which the isocyanate composition (X) or the isocyanate-reactive composition (Y) does not substantially contain the highly soluble organic solvents described above, particularly ethyl acetate or methyl ethyl ketone, and the adhesive is applied to a substrate and then laminated to another substrate without a process of volatilizing the solvent by heating in an oven or the like, which is known as a non-solvent lamination method.
• the adhesive does not substantially contain an organic solvent.
• the isocyanate-reactive composition (Y) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the isocyanate composition (X) to become part of the coating film, so there is no need to volatilize it after application. Therefore, such a form is also treated as a solvent-free adhesive.
• the adhesive of the present invention is preferably used in a formulation in which the ratio [NCO]/[OH] of the number of moles of isocyanate groups [NCO] contained in the isocyanate composition (X) to the number of moles of hydroxyl groups [OH] contained in the isocyanate-reactive composition (Y) is 0.8 to 3.0, more preferably 1.0 to 3.0.
• the adhesive of the present invention is preferably adjusted so that the acid value after curing is 5 mgKOH/g or more and 50 mgKOH/g or less.
• the acid value of the adhesive can be adjusted by the acid value of the active hydrogen group-containing compound (B), the amount of the acid group-containing compound (C) added, the [NCO]/[OH] ratio between the isocyanate composition (X) and the isocyanate-reactive composition (Y), etc. This makes it possible to obtain an adhesive with better peelability.
• the laminate of the present invention is obtained by laminating a plurality of substrates (films or papers) using the adhesive of the present invention.
• a film can be appropriately selected according to the application.
• polyolefin films such as polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: non-oriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc.
• PET polyethylene terephthalate
• polystyrene film polyamide film
• polyacrylonitrile film polyethylene film
• LLDPE low density polyethylene film
• HDPE high density polyethylene film
• CPP non-oriented polypropylene film
• OPP biaxially oriented polypropylene film
• polyvinyl alcohol film
• the film may be one that has been stretched.
• a typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-making method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching.
• sequential biaxial stretching it is common to first perform longitudinal stretching, and then transverse stretching. Specifically, a method that combines longitudinal stretching using the speed difference between rolls and transverse stretching using a tenter is often used.
• the film surface may be subjected to various surface treatments such as flame treatment or corona discharge treatment to ensure that an adhesive layer is formed that is free of defects such as film breaks or repellency.
• a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film containing a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride may be used.
• a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride
• the paper can be made from any known paper base material without any particular limitations.
• the paper is made from natural fibers for papermaking such as wood pulp using a known papermaking machine, but the papermaking conditions are not particularly regulated.
• natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal hemp pulp, and flax pulp, and pulps obtained by chemically modifying these pulps.
• Types of pulp that can be used include chemical pulp made by sulfate cooking, acidic/neutral/alkaline sulfite cooking, soda cooking, etc., ground pulp, chemi-ground pulp, thermomechanical pulp, etc.
• various commercially available fine papers, coated papers, backing papers, impregnated papers, cardboard, and paperboard can also be used.
• the laminate has the following structure: (1) Substrate 1/adhesive layer 1/sealant film (2) Substrate 1/adhesive layer 1/metal-vapor-deposited unstretched film (3) Substrate 1/adhesive layer 1/metal-vapor-deposited stretched film (4) Transparent vapor-deposited stretched film/adhesive layer 1/sealant film (5) Substrate 1/adhesive layer 1/substrate 2/adhesive layer 2/sealant film (6) Substrate 1/adhesive layer 1/metal-vapor-deposited stretched film/adhesive layer 2/sealant film (7) Substrate 1/adhesive layer 1/transparent vapor-deposited stretched film/adhesive layer 2/sealant film (8) Substrate 1/adhesive layer 1/metal layer/adhesive layer 2/sealant film (9) Substrate 1/ad
• the substrate 1 used in the structure (1) may be an MDOPE film, an OPE film, an OPP film, a PET film, a nylon film, paper, or the like.
• the substrate 1 may be coated with a coating for the purpose of improving the gas barrier properties or the ink receptivity when a printing layer is provided, which will be described later.
• Examples of commercially available substrate films 1 with coatings include K-OPP films and K-PET films.
• the adhesive layer 1 is a cured coating film of the adhesive of the present invention.
• sealant films include CPP films, LLDPE films, and gas barrier heat seal films.
• a printing layer may be provided on the adhesive layer 1 side of the substrate 1 (when a substrate film 1 with coating is used, the adhesive layer 1 side of the coating layer) or on the side opposite to the adhesive layer 1.
• the printing layer is formed by a general printing method that has been used for printing on polymer films and paper using various printing inks such as gravure ink, flexo ink, offset ink, stencil ink, and inkjet ink.
• the substrate 1 used in the structures (2) and (3) may be an MDOPE film, an OPE film, an OPP film, a PET film, paper, or the like.
• the adhesive layer 1 is a cured coating of the adhesive of the present invention.
• a CPP film, an LLDPE film, a VM-CPP film or a VM-LLDPE film obtained by depositing a metal such as aluminum on a gas-barrier heat seal film, or the like may be used.
• a VM-MDOPE film, a VM-OPE film, or a VM-OPP film obtained by depositing a metal such as aluminum on an MDOPE film, an OPE film, or an OPP film may be used.
• a printing layer may be provided on either side of the substrate 1, or the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, or the like.
• the transparent vapor-deposited stretched film used in configuration (4) may be a film obtained by vapor-depositing silica or alumina onto an MDOPE film, an OPE film, an OPP film, a PET film, a nylon film, or the like.
• a film having a coating applied onto the vapor-deposited layer of silica or alumina may be used for the purpose of protecting the inorganic vapor-deposited layer.
• the adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of the sealant film include the same as those in configuration (1).
• a printed layer may be provided on the surface of the transparent vapor-deposited stretched film on the adhesive layer 1 side (when a film having a coating applied onto the inorganic vapor-deposited layer is used, the surface of the coating layer on the adhesive layer 1 side).
• the method of forming the printed layer is the same as in configuration (1).
• Examples of the substrate 1 used in configuration (5) include PET film, paper, etc.
• Examples of the substrate 2 include nylon film, etc.
• Either the adhesive layer 1 or the adhesive layer 2 is a cured coating of the adhesive of the present invention.
• Either the adhesive layer 1 or the adhesive layer 2 may be a cured coating of the adhesive of the present invention.
• Examples of the sealant film include those similar to those in configuration (1).
• a printing layer may be provided on either side of the substrate 1, or the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, etc.
• the substrate 1 in the structure (6) may be the same as those in the structures (2) and (3).
• Metal-vapor-deposited stretched films include VM-MDOPE film, VM-OPE film, VM-OPP film, and VM-PET film, which are MDOPE film, OPE film, OPP film, and PET film that have been subjected to metal vapor deposition of aluminum or the like.
• Either the adhesive layer 1 or the adhesive layer 2 is a cured coating film of the adhesive of the present invention.
• Either the adhesive layer 1 or the adhesive layer 2 may be a cured coating film of the adhesive of the present invention.
• the sealant film may be the same as those in the structure (1).
• a printing layer may be provided on either side of the substrate 1, and the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, etc.
• Examples of the substrate 1 in structure (7) include PET film, paper, etc.
• Examples of the transparent vapor deposition stretched film include those similar to those in structure (4).
• Either of the adhesive layers 1 and 2 is a cured coating of the adhesive of the present invention.
• Either of the adhesive layers 1 and 2 may be a cured coating of the adhesive of the present invention.
• Examples of the sealant film include those similar to those in structure (1).
• a printing layer may be provided on either side of the substrate 1, or the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, etc.
• Examples of the substrate 1 in structure (8) include PET film, paper, etc.
• Examples of the metal layer include aluminum foil, etc.
• Either of the adhesive layers 1 and 2 is a cured coating of the adhesive of the present invention.
• Either of the adhesive layers 1 and 2 may be a cured coating of the adhesive of the present invention.
• Examples of the sealant film include those similar to those in structure (1).
• a printing layer may be provided on either side of the substrate 1, or the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, etc.
• examples of the substrate 1 include PET film, paper, etc.
• examples of the substrate 2 include nylon film, etc.
• Examples of the metal layer include aluminum foil, etc.
• Any of the adhesive layers 1, 2, and 3 is a cured coating of the adhesive of the present invention.
• Any of the adhesive layers 1, 2, and 3 may be a cured coating of the adhesive of the present invention.
• Examples of the sealant film include the same as those in structure (1).
• a printing layer may be provided on either side of the substrate 1, or the substrate 1 may be coated with a coating for the purpose of improving ink receptivity, etc.
• the printed layer may be formed from a deinkable ink (a printing ink designed to be easily peeled off from the resin film when immersed in a basic solution). Forming the printed layer from a deinkable ink is preferable because it makes it easier to peel off the printed layer from the substrate in a shorter time, improving recyclability.
• a deinkable ink a printing ink designed to be easily peeled off from the resin film when immersed in a basic solution.
• the coating may also be formed from a composition designed to improve adhesion between the printed layer and the substrate, as well as to facilitate peeling from the resin film by immersion in a basic solution. This is preferable because it makes it easier for the printed layer to peel from the laminate in a shorter time, improving recyclability.
• compositions include, but are not limited to, compositions containing a resin with an acidic group and compositions containing an additive with an acidic group.
• the adhesive of the present invention is a solvent-based adhesive
• the adhesive of the present invention is applied to a film material as a substrate using a roll such as a gravure roll, and the organic solvent is evaporated by heating in an oven or the like, and then the other substrate is laminated to obtain the laminate of the present invention.
• a roll such as a gravure roll
• the organic solvent is evaporated by heating in an oven or the like
• the other substrate is laminated to obtain the laminate of the present invention.
• the aging temperature is preferably room temperature to 80°C
• the aging time is preferably 12 to 240 hours.
• the adhesive of the present invention is a solventless type
• the adhesive of the present invention which has been preheated to about 40°C to 100°C, is applied to the film material that will serve as the substrate using a roll such as a gravure roll, and the other substrate is immediately laminated to obtain the laminate of the present invention.
• a roll such as a gravure roll
• the other substrate is immediately laminated to obtain the laminate of the present invention.
• an aging treatment is preferably room temperature to 70°C, and the aging time is preferably 6 to 240 hours.
• the amount of adhesive applied is adjusted as appropriate, but in the case of a solvent-based adhesive, the amount of solids is adjusted to, for example, 1 g/ m2 to 10 g/ m2 , preferably 2 g/ m2 to 5 g/ m2 . In the case of a solventless adhesive, the amount of adhesive applied is, for example, 1 g/ m2 to 5 g/ m2 , preferably 1 g/ m2 to 3 g/ m2 .
• the packaging material of the present invention is obtained by forming the above-mentioned laminate into a bag shape and heat sealing it to obtain the form of the packaging material.
• the packaging material may be in the form of a three-side sealed bag, a four-side sealed bag, a gusseted packaging bag, a pillow packaging bag, a Goebel Top type bottomed container, a Tetra Classic, a Brueck type, a tube container, a paper cup, a lid, etc.
• the packaging material of the present invention may also be appropriately provided with an easy-opening treatment or a resealable means.
• the packaging material of the present invention is filled with the contents through its opening, and the opening is then heat-sealed to produce a product using the packaging material of the present invention.
• the contents to be filled include, for example, foods such as rice crackers, bean snacks, nuts, biscuits and cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candies, and snack foods; staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, porridge, packaged rice cakes, and cereal foods; agricultural processed products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, wild vegetable processed products, jams, peanut cream, salads, frozen vegetables, and potato processed products; livestock processed products such as ham, bacon, sausages, chicken processed products, and corned beef; and fish ham, These include processed seafood products such as sausages, fish paste products, kamaboko, nori, tsukudani (food boiled in soy
• composition can be used as a packaging material for various non-food items, such as tobacco, disposable hand warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and milky lotion, vacuum insulation materials, batteries, etc.
• non-food items such as tobacco, disposable hand warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and milky lotion, vacuum insulation materials, batteries, etc.
• non-food items such as tobacco, disposable hand warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and milky lotion, vacuum insulation materials, batteries, etc.
• the packaging material of the present invention can also be used as a secondary packaging material for packaging the above-mentioned containers.
• the laminate of the present invention can be separated into the respective substrates and recovered by a treatment using an alkaline solution, which is currently the most widely used recycling treatment.
• the laminate can be immersed in an alkaline solution while being heated and stirred at 20 to 90° C., whereby the substrate and the adhesive layer are peeled off, and the substrates can be separated and recovered.
• the alkaline solution used in the separation and recovery method is preferably an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution.
• the aqueous sodium hydroxide solution or the aqueous potassium hydroxide solution has a concentration of preferably 0.5% to 10% by mass, and more preferably 1% to 5% by mass.
• the pH is preferably 10 or higher.
• the alkaline solution may contain a water-soluble organic solvent.
• water-soluble organic solvents 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.
• Examples include ethylene glycol monomethyl 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 may be used alone or in combination of two or more.
• the content of the water-soluble organic solvent in the alkaline solution is preferably 30% to 70% by mass, and more preferably 40% to 60% by mass.
• the alkaline solution may contain a water-insoluble organic solvent.
• water-insoluble organic solvents include alcohol-based solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon-based solvents such as hexane, heptane, and normal paraffin; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, and alkylbenzene; halogenated hydrocarbon-based solvents such as methylene chloride, 1-chlorobutane, 2-chlorobutane, 3-chlorobutane, and carbon tetrachloride; ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone-based solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; and ether-based solvent
• the alkaline solution may contain a surfactant.
• the surfactant include various anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and among these, anionic surfactants and nonionic surfactants are preferred.
• anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfates of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfates and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates.
• dodecylbenzenesulfonates include dodecylbenzenesulfonates, isopropylnaphthalenesulfonates, monobutylphenylphenol monosulfonates, monobutylbiphenylsulfonates, and dibutylphenylphenol disulfonates.
• nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkylol amides, alkyl alkanol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, and the like.
• polyoxyethylene nonylphenyl ether polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers are preferred.
• surfactants that can be used include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• silicone surfactants such as polysiloxane oxyethylene adducts
• fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers
• biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.
• surfactants can be used alone or in combination of two or more.
• the amount added is preferably in the range of 0.001 to 2 mass % of the total amount of the alkaline solution, more preferably 0.001 to 1.5 mass %, and even more preferably 0.01 to 1 mass %.
• the alkaline solution preferably contains a terpene compound.
• the terpene compound include monoterpenes such as ⁇ -pinene, ⁇ -pinene, limonene, ⁇ -phellandrene, ⁇ -terpinene, ⁇ -terpinene, aucimene, myrcene, camphene, terpinolene, sylvestrene, sabinene, carene, tricyclene, and fenthene; sesquiterpenes such as longifolene, caryophyllene, bizabolene, santalene, zingiberene, curcumene, cadinene, sesquibenihen, and cedrene; and diterpenes such as campholene, podocarpulene, myrene, phyllocladene, and totarene.
• Monoterpene alcohols such as ⁇ -citronellol, geraniol, nerol, linalool, terpineol, carpeol, thuyl alcohol, pinocampheol, and fenchyl alcohol; sesquiterpene alcohols such as farnesol, nerolidol, casinol, eudesmol, guayol, baturyl alcohol, carotol, lanceol, and kessoglycol; terpene alcohols such as diterpene alcohols such as phytol, sclareol, manol, hinokitiol, ferruginol, and totarol;
• Terpene aldehydes such as citronellal, citral, cyclocitral, safranal, ferrandolal, and perillaldehyde,
• monoterpene ketones such as dagetone, ionone, irone, carbomentone, carbotanacetone, piperitenone, thujone, and calone; sesquiterpene ketones such as cyperone, eremophilone, and zerumbone; and diterpene ketones such as sugiol and ketomanoyl oxide.
• terpene hydrocarbons and it is more preferable to use limonene.
• the content of the terpene compound can be adjusted as appropriate, but as an example, it is preferably 0.1% by mass or more and 90% by mass or less of the alkaline solution, more preferably 1% by mass or more, and even more preferably 5% by mass or more. It is also more preferable that the content of the terpene compound is 50% by mass or less of the alkaline solution.
• the laminate is immersed in an alkaline solution heated to 20 to 90°C in a treatment tank.
• an alkaline solution heated to 20 to 90°C heated to 20 to 90°C in a treatment tank.
• heating method there are no particular limitations on the heating method, and known heating methods using heat rays, infrared rays, microwaves, etc. can be used.
• Ultrasonic vibrations may be applied during immersion.
• a method can be used in which an ultrasonic vibrator is attached to the treatment tank and ultrasonic vibrations are applied to the alkaline solution.
• the alkaline solution is preferably stirred when the laminate is immersed in it.
• Stirring methods include mechanically stirring the dispersion of the laminate contained in the treatment tank with a stirring blade, water flow stirring with a water flow pump, and bubbling with an inert gas such as nitrogen gas. These methods may be used in combination to efficiently peel off the laminate.
• the time for which the laminate is immersed in the alkaline solution depends on the composition of the laminate, but is generally in the range of 2 minutes to 48 hours. If the immersion time is less than 2 minutes, there is a risk that the adhesive layer will not completely peel off from the laminate and some of it will remain.
• the laminate may be immersed in the alkaline solution once or in several separate sessions.
• the laminate has an adhesive and a printed ink layer to display the product name and provide decorativeness, but the printed ink layer can also be peeled off or dissolved by immersing the laminate in an alkaline solution.
• the laminate also has a metal foil or vapor deposition film such as aluminum laminated on it, but in the present invention, the metal foil or vapor deposition film can also be peeled off or dissolved.
• the alkaline solution used in the separation and recovery method is presumed to act on the interface between the laminate and the adhesive or printing ink, significantly reducing the adhesive strength, causing interfacial peeling between the laminate and the adhesive or printing ink.
• cross-linked coatings of reactive adhesives and the like hardly dissolve in any solution, but in the present invention, they are not dissolved but rather cause interfacial peeling, which is presumed to enable efficient separation and recovery in a short time.
• intermediate polyester polyol (b-1) and 7.7 parts of trimellitic anhydride were placed in a reaction vessel in a flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, and heated to 75°C while stirring under a nitrogen gas atmosphere. The mixture was stirred for 8 hours to add acid. The mixture was diluted with ethyl acetate to a non-volatile content of 75%, yielding polyester polyol (B-1) with an acid value of 28.9 mg KOH/g and a viscosity of 1,400 mPa ⁇ s.
• AA Adipic acid IPA: Isophthalic acid TPA: Terephthalic acid DA: Dimer acid "Tsuno Dime 216" (aliphatic dibasic acid manufactured by Tsuno Food Industry Co., Ltd.) DEG: Diethylene glycol EG: Ethylene glycol NPG: Neopentyl glycol TMP: Trimethylolpropane
• intermediate polyester polyol (b-4) and 12.9 parts of trimellitic anhydride were placed in a flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, and heated to 75°C while stirring under a nitrogen gas atmosphere. The mixture was stirred for 8 hours to add acid. The mixture was diluted with ethyl acetate to a non-volatile content of 85%, yielding polyester polyol (B-4) with an acid value of 46.8 mg KOH/g and a viscosity of 1000 mPa ⁇ s.
• the average functional groups and number average molecular weights of the polyester polyols (B-4), (B-5) and (B′-2) are shown in Table 3.
• the polyester polyols (B-2) to (B-5), (B'-1), and (B'-2) were mixed with the acid group-containing compound (C) in the proportions shown in Table 4 to obtain isocyanate-reactive compositions (Y-2) to (Y-10), (Y'-1) to (Y'-2).
• the adhesives of the Examples and Comparative Examples were obtained by mixing the isocyanate composition (X) and the isocyanate-reactive composition (Y) heated to 40°C in the formulations (solid content) shown in Tables 4 to 6.
• the acid value in the tables is the acid value of the cured coating film of the adhesive (a value calculated from the blending ratio [NCO]/[OH] of the active hydrogen group-containing compound (B), the acid group-containing compound (C) used, and the isocyanate composition (X) and the isocyanate-reactive composition (Y)).
• OPP/adhesive layer/CPP An adhesive of the Example or Comparative Example was applied to an OPP film (P2161, manufactured by Toyobo Co., Ltd.) so that the application amount (solid content) was 3 g/ m2 , and the film was laminated to a CPP film (P1128, manufactured by Toyobo Co., Ltd.). Aging was performed for 3 days at 40°C to obtain an OPP/adhesive layer/CPP laminate.
• a urethane laminating ink (DIC Corporation, Finart R507 indigo) was adjusted to 15 seconds (25° C.) using a Rigo Zahn Cup #3, and a gravure printing machine equipped with a gravure plate with a plate depth of 43 ⁇ m was used to print the OPP film.
• the printing was performed on a paper (P2161, manufactured by Toyobo Co., Ltd.) and the paper was passed through an oven at 70° C. to dry and harden the paper, forming a printed layer (indigo blue).
• the mixture was adjusted to 15 seconds (25°C) using a Zahn Cup #3 manufactured by Rigo Co., Ltd., printed on a printing layer (indigo blue) using a gravure printing machine equipped with a gravure plate with a plate depth of 43 ⁇ m, and passed through an oven at 70°C. This allowed it to dry and harden, forming a printed layer (white).
• the adhesive of the Example or Comparative Example was applied onto the printed layer (white) so that the application amount (solid content) was 3 g/ m2 , and the layer was laminated with a CPP film (P1128, manufactured by Toyobo Co., Ltd.). After aging for 3 days, a laminate of OPP/printed layer (indigo blue)/printed layer (white)/adhesive layer/CPP was obtained.
• the laminate obtained above was cut into a size of 20 mm x 20 mm to prepare a test piece.
• the test piece was immersed in a release agent heated to 70°C and stirred at 400 rpm. After immersion, the test piece was removed, washed with ion-exchanged water, dried, and the peeled area (%) of the adhesive was examined by coloring with neocarmine. If the adhesive was completely peeled off, it was considered to be 100%.
• the immersion time was 3 hours.
• the release solution used was a mixture of 48 parts water and 50 parts ethanol, with 2 parts sodium hydroxide dissolved in it. A peeled area (%) of 70% or more is considered to be acceptable, and a peeled area (%) of 90% or more is considered to be particularly excellent.
• Tables 4 to 6 The results are summarized in Tables 4 to 6.

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