Laminate, packaging material, and method for producing recycled base material

Abstract

Provided is a laminate comprising a base material A, an anchor layer, and a vapor deposition layer in the stated order, the laminate being such that the anchor layer is a film formed from a composition containing at least a urethane resin (A), the urethane resin (A) is composed of a reaction product of polyester polyol (a1) and polyisocyanate (a2), the ester bond group concentration in the urethane resin (A) is 1 mmol / g or greater, and the acid value of the urethane resin (A) is 8-45 mg KOH / g.

Description

Method for producing laminate, packaging material, and recycled base material

[0001] The present invention relates to a laminate having a deposited layer, a packaging material using the laminate, and a method for producing a recycled base material.

[0002] In recent years, the marine plastic problem caused by plastics discarded and dumped in the ocean being decomposed in seawater and refined into fine particles (converted into microplastics) has become apparent. There is concern that these microplastics may enter the bodies of marine organisms, be concentrated, and affect the health of seabirds and humans through the food chain. One of the methods to improve this marine plastic problem is recycling. Improving the recycling rate of resources such as flexible packaging materials and plastic bottles helps prevent plastics from entering the ocean. However, in current recycling practices, the printed layer printed on the plastic base material does not detach during the regeneration process and mixes into the plastic, causing deterioration of hue and degradation of physical properties, which poses the problem of reducing the value of the recycled plastic. If this problem can be solved by enabling the detachment of the film from the plastic base material in the recycling process, the value of recycled plastic will be improved, which will lead to the entry of new recycling operators and the development of sorted collection systems by local governments. This is considered to improve the marine plastic problem by increasing the recycling rate. Therefore, there is a demand for the development of a method for detaching a film from a plastic base material in the recycling process. In addition, film-forming materials widely used for plastic base materials are being increasingly replaced with toluene-free and methyl ethyl ketone (MEK)-free alternatives in consideration of the effects on worker health and the environment, so materials that solve the above problems also need to be developed in consideration of this point.

[0003] Conventional technologies disclose a method for desolving a film containing styrene-acrylic resin, phenolic resin, and styrene-maleic resin as a vehicle, printed on a heat-shrinkable PET film, using alkaline water (Patent Document 1). Similarly, a method is disclosed in which a coating layer containing styrene-maleic resin, rosin-maleic resin, and acrylic copolymer resin is placed between the printed layers of a heat-shrinkable PET film, and the coating layer is desolving using alkaline water (Patent Documents 2 and 3). However, these technologies only guarantee properties for specific heat-shrinkable PET substrates and have limitations such as requiring the addition of a coating layer separate from the film layer, making them unsuitable for recycling general-purpose plastic substrates including polyolefins.

[0004] Furthermore, in recent years, there has been an increasing trend towards high-performance films (barrier films) with various barrier properties being used in film packaging. Barrier films have multiple layers, including a metal oxide vapor-deposited film layer (vapor-deposited layer) used as a barrier layer, an anchor layer to ensure adhesion of the vapor-deposited layer, and a protective layer to prevent a decrease in barrier properties due to cracks in the vapor-deposited layer (Patent Document 4). To improve the recycling rate of packaging, recycling of the plastic substrates used in such barrier films is also desired.

[0005] Japanese Patent Publication No. 3822738, Japanese Patent Publication No. 4653913, Japanese Patent Publication No. 4451071, Japanese Patent Application Publication No. 2024-48725

[0006] In the recycling of barrier films having a vapor-deposited layer, simply applying a film containing styrene-acrylic acid resin, phenolic resin, styrene-maleic acid resin, etc. as a vehicle on the barrier film, as described in Patent Documents 1 to 3, and removing the film layer by desorption with alkaline water, is insufficient for removing the vapor-deposited layer, anchor layer, protective layer, etc., raising concerns about a decline in the quality of the recycled material. However, despite the special structure of such barrier films having a vapor-deposited layer, the optimal configuration and method for desorption of the vapor-deposited layer, etc., has not been sufficiently investigated. Therefore, the problem that the present invention aims to solve is to provide a barrier film having a vapor-deposited layer that has excellent adhesion during normal use in applications such as packaging materials, while allowing for easy removal of the vapor-deposited layer, etc., from the film substrate with a simple configuration and method.

[0007] As a result of extensive research to solve the above problems, the inventors discovered that the above problems could be solved by using a specific aqueous urethane resin composition as an anchor layer, and thus completed the present invention. The anchor layer using the specific aqueous urethane resin composition functions as an anchor layer to improve the adhesion between the vapor-deposited layer and the substrate, and also makes it possible to remove the vapor-deposited layer and other components by treatment with an alkaline solution during recycling.

[0008] In other words, the present invention encompasses the following embodiments: [1] A laminate having a base material A, an anchor layer, and a vapor-deposited layer in that order, wherein the anchor layer is a film formed from a composition containing at least a urethane resin (A), the urethane resin (A) is a reaction product of a polyester polyol (a1) and a polyisocyanate (a2), the ester bond group concentration in the urethane resin (A) is 1 mmol / g or more, and the acid value of the urethane resin (A) is 8 to 45 mg KOH / g. [2] The laminate according to [1], wherein the polyester polyol (a1) is an aromatic polyester polyol containing an aromatic dicarboxylic acid (a1-1) as a raw material monomer, and the aromatic ring concentration derived from the raw material monomer of the aromatic dicarboxylic acid (a1-1) in the urethane resin (A) is 1 mmol / g or more. [3] The laminate according to [1] or [2], wherein the polyisocyanate (a2) is at least one selected from the group consisting of isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate. [4] The laminate according to [1] or [2], wherein the value obtained by dividing the mass of the raw material monomer of the polyisocyanate (a2) contained in 1 g of the urethane resin (A) by the NCO equivalent weight of the raw material monomer of the polyisocyanate (a2) is 1.0 to 6.0 mmol / g. [5] The laminate according to [1] or [2], wherein the weight-average molecular weight of the urethane resin (A) is 10,000 or more. [6] The laminate according to [1] or [2], wherein the glass transition temperature of the urethane resin (A) is 0 to 110°C. [7] The laminate according to [1] or [2], having a protective layer on the vapor-deposited layer. [8] A laminate according to [1] or [2], wherein another substrate is bonded to the surface of the substrate A on which the vapor-deposited layer is arranged. [9] A laminate according to [8], wherein at least one layer selected from a printing layer, a barrier coat layer, an adhesive layer, a metal layer, and other vapor-deposited layers is placed between the vapor-deposited layer and the other substrate.

[10] A packaging material using the laminate according to [1].

[11] A method for producing a recycled substrate A, obtained by treating the laminate described in [1] with an alkaline solution to detach the vapor-deposited layer together with the anchor layer from the substrate A.

[0009] The present invention allows for the easy removal of the anchor layer from a laminate having a vapor-deposited layer using a simple structure and method, thereby enabling the removal of the vapor-deposited layer and other components from the film substrate. This improves the recyclability of laminates having vapor-deposited layers and enhances the quality of recycled plastics using the plastic film after the vapor-deposited layer has been removed. The laminate of the present invention exhibits excellent adhesion of the vapor-deposited layer to the substrate during normal use, and also has excellent oxygen barrier properties.

[0010] The present invention will be described in detail below. The following description of the constituent elements is illustrative for illustrating the present invention, and the present invention is not limited to these elements.

[0011] The laminate of the present invention is a laminate having at least a base material A, an anchor layer, and a vapor-deposited layer in this order. (Anchor layer) The anchor layer of the present invention contains a urethane resin (A) which is a reaction product of polyester polyol (a1) and polyisocyanate (a2). The urethane resin (A) is a reaction product of polyester polyol (a1) and polyisocyanate (a2), the concentration of ester bond groups in the urethane resin (A) is 1 mmol / g or more, and the acid value of the urethane resin (A) is 8 to 45 mgKOH / g. The anchor layer is a film (layer) formed by an aqueous urethane resin composition containing urethane resin (A) and an aqueous medium (B). In the present invention, the anchor layer functions as an anchor layer to improve adhesion between the vapor-deposited layer and the base material, and as a film to remove the vapor-deposited layer etc. by treatment with an alkaline solution during recycling. (Aqueous urethane resin composition containing urethane resin (A)) The aqueous urethane resin composition that forms the anchor layer of the present invention contains urethane resin (A) and an aqueous medium (B). The aqueous urethane resin composition of the present invention is a urethane resin (A) obtained by reacting a polyester polyol (a1), a polyisocyanate (a2), and optionally a chain extender, dispersed in an aqueous medium (B). The concentration of ester bond groups in the urethane resin (A) is 1 mmol / g or more. The acid value of the urethane resin (A) is 8 to 45 mgKOH / g.

[0012] <Urethane Resin (A)> Urethane resin (A) is a general term for polymer compounds having urethane bonds (-NHCOO-), and in the present invention, it consists of a reaction product obtained by reacting (crosslinking and curing reaction) polyester polyol (a1) and polyisocyanate (a2). In addition to polyester polyol (a1) and polyisocyanate (a2), urethane resin (A) may also contain other polyols (a3), and may be a reaction product of polyester polyol (a1), polyisocyanate (a2), and other polyols (a3).

[0013] <<Polyester polyol (a1)>> Polyester polyols can be produced, for example, by reacting a polycarboxylic acid having two or more carboxyl groups with a polyol having two or more hydroxyl groups.

[0014] Examples of polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, and their acid anhydrides, as well as dicarboxylic acids such as trimellitic acid and its anhydride, benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid, and anhydrides of these acids.

[0015] Plant-derived raw materials can also be used as polycarboxylic acids. Using plant-derived polycarboxylic acids is preferable because it can increase the biomass content of the ink. Examples of plant-derived polycarboxylic acids include succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, and malic acid.

[0016] Examples of polyols include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butynediol, 1,4-butylenediol, etc.; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl Branched glycols such as 2-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, and 2-methyl-1,8-octanediol can be used; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, 1,2,6-hexanetriol, 1,2,4-butanetriol, etc. can be used.

[0017] Plant-derived raw materials can also be used as polyols. Using plant-derived polyols is preferable because it can increase the biomass content of the ink. Examples of plant-derived polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer diol, and isosorbide.

[0018] In urethane resin (A), in order to enhance the oxygen barrier properties of the anchor layer, it is preferable to use aromatic dicarboxylic acid (a1-1) as the raw material monomer for polyester polyol (a1). That is, it is preferable that the urethane resin (A) of the present invention consists of a reaction product obtained by reacting (crosslinking and curing reaction) aromatic polyester polyol and polyisocyanate (a2).

[0019] <<Aromatic Polyester Polyols>> Aromatic polyester polyols can be produced, for example, by esterifying an aromatic dicarboxylic acid (a1-1) with a polyol (a1-2).

[0020] Examples of aromatic dicarboxylic acids (a1-1) that can be used when producing aromatic polyester polyol (a1) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic 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, as well as their acid anhydrides or ester-forming derivatives, aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and their ester-forming derivatives, and sulfonic acid group-containing aromatic dicarboxylic acids such as 5-sulfisophthalic acid and their ester-forming derivatives.

[0021] Furthermore, in addition to the aromatic dicarboxylic acid (a1-1), it is also preferable to use aliphatic carboxylic acids or alicyclic carboxylic acids in combination. Examples include aliphatic dicarboxylic acids such as succinic acid, succinic anhydride, adipic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, maleic anhydride, and fumaric acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, their anhydrides, or ester-forming derivatives. These may be used alone or in combination of two or more.

[0022] Examples of polyols (a1-2) that can be used include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, neopentyl glycol, etc.

[0023] Specifically, an aromatic dicarboxylic acid (a1-1) and a polyol (a1-2) can be reacted under atmospheric or reduced pressure in a reaction vessel substituted with an inert gas such as nitrogen, in the presence of a catalyst as needed. The reaction is preferably carried out in the range of 100°C to 300°C.

[0024] As catalysts, for example, acetates of alkali metals or alkaline earth metals, or compounds containing zinc, manganese, cobalt, antimony, germanium, titanium, tin, zirconium, etc., can be used. Among these, it is preferable to use tetraalkyl titanates or tin oxalate, which are effective in transesterification and polycondensation reactions.

[0025] When manufacturing urethane resin (A), aromatic polyester polyol (a1) and polyisocyanate (a2) can be used in combination with other polyols (a3), etc.

[0026] Other polyols (a3) ​​can be the same as those used for polyols (a1-2) above. For example, relatively low molecular weight polyols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, and neopentyl glycol can be used.

[0027] <<Polyether Polyol>> It is preferable that the polyurethane resin contains a polyether polyol as a component. Known polyether polyols can be used as the polyether polyol.

[0028] It is preferable that the polyurethane resin contains polyether polyol in an amount of 1 to 40% by mass relative to the polyurethane resin. In particular, it is even more preferable that the polyether polyol be contained in an amount of 1 to 30% by mass relative to the polyurethane resin, and most preferably in an amount of 1 to 20% by mass. If the amount of polyether polyol relative to the polyurethane resin is 1% by mass or more, the solubility of the polyurethane resin in ketone, ester, and alcohol-based solvents is good, and the resolubility of the ink film in these solvents does not easily decrease, and the tone reproducibility of printed materials does not easily deteriorate. Furthermore, if the amount of polyether polyol relative to the polyurethane resin is 40% by mass or less, the blocking resistance does not easily decrease.

[0029] Furthermore, the Mn of the polyether polyol is preferably between 100 and 4,000. If the Mn of the polyether polyol is 100 or higher, the polyurethane resin film does not harden and its adhesion to the polyester film is less likely to decrease. If the Mn is 4,000 or lower, the polyurethane resin film has sufficient strength and the blocking resistance of the ink layer tends not to decrease.

[0030] Examples of polyether polyols include difunctional alcohols (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, and 1,4-cyclohexanedimethanol; trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol; and bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F. Furthermore, examples of polyether polyols include polyether polyols such as polytetramethylene glycol, polypropylene glycol, polyethylene glycol, and polytrimethylene glycol, which are 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 polymerization initiators such as glycol and trifunctional or tetrafunctional aliphatic alcohols; and polyether urethane polyols, which are obtained by further increasing the molecular weight of the polyether polyol with aromatic or aliphatic polyisocyanates.

[0031] <<Polyisocyanate (a2)>> As the polyisocyanate (a2) that reacts with polyol (a1) to form urethane resin (A), for example, aromatic diisocyanates such as phenylenediisocyanate, tolylenediisocyanate, diphenylmethanediisocyanate, and naphthalenediisocyanate, or aliphatic or aliphatic cyclic structure-containing diisocyanates such as hexamethylenediisocyanate, lysinediisocyanate, cyclohexanediisocyanate, isophoronediisocyanate, dicyclohexylmethanediisocyanate, xylylenediisocyanate, and tetramethylxylylenediisocyanate can be used alone or in combination of two or more. In particular, using one or more selected from the group consisting of isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate is more preferable from the viewpoint of improving the adhesion and deinking properties of the resulting primer layer to the substrate.

[0032] The urethane resin (A) can be produced, for example, by reacting the aromatic polyester polyol (a1), the polyisocyanate (a2), the polyol (a3) ​​if necessary, and the chain extender if necessary, either without a solvent or in the presence of an organic solvent. When the organic solvent is used, it is preferable to remove the organic solvent by distillation or other means as necessary when dispersing the urethane resin (A) in an aqueous medium (B).

[0033] Organic solvents that can be used when manufacturing urethane resin (A) include, for example, ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetic acid esters such as ethyl acetate and butyl acetate; nitriles such as acetonitrile; and dimethylformamide and N-methylpyrrolidone, which can be used individually or in combination of two or more.

[0034] Chain extenders that can be used in the production of urethane resin (A) can be used to increase the molecular weight of urethane resin (A) and improve the durability of the resulting film or the like. Examples of chain extenders that can be used in the production of urethane resin (A) include polyamines and other active hydrogen atom-containing compounds.

[0035] Examples of polyamines include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, and other diamines; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethyl Lentriamine, dipropylenetriamine, triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinate dihydrazide, adipic acid dihydrazide, glutarate dihydrazide, sebacate dihydrazide, isophthalate dihydrazide; β-semicarbazide propionic acid hydrazide, 3-semicarbazide-propylcarbadic acid ester, semicarbazide-3-semicarbazidemethyl-3,5,5-trimethylcyclohexane can be used, and ethylenediamine is preferred.

[0036] Other active hydrogen-containing compounds that can be used include, for example, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, saccharose, methylene glycol, glycerin, and sorbitol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, and hydroquinone, as well as water.

[0037] The chain extender can be used when reacting the aromatic polyester polyol (a1) and the polyisocyanate (a2) described above, or after the reaction. The chain extender can also be used when dispersing the urethane resin (A) in an aqueous medium (B) to make it aqueous.

[0038] <<Properties of Urethane Resin (A)>>

[0039] The ester bond group concentration in the urethane resin (A) is 1 mmol / g or more. This ester bond group concentration can be determined by calculating the number of moles of ester bond groups contained in 1 g of urethane resin (A). The specific calculation method will be described later. From the viewpoint of improving the adhesion and deinking properties of the resulting primer layer, the ester bond group concentration is preferably 2 mmol / g or more, more preferably 4 mmol / g or more, and from the viewpoint of good blocking resistance of the primer layer, it is preferably 9 mmol / g or less, more preferably 7 mmol / g or less.

[0040] The acid value of the urethane resin (A) is 8 to 45 mgKOH / g. The acid value is a value obtained by converting the acid amount in 1 g of the resin calculated by titrating the acid with an alkali into the number of mg of potassium hydroxide, and is a value measured in accordance with JIS K0070. When the acid value is 8 mgKOH / g or more, the water dispersion stability can be improved, it is preferably 15 mgKOH / g or more, and more preferably 20 mgKOH / g or more. When the acid value is 45 mgKOH / g or less, good adhesion to the polyester base material can be ensured, it is preferably 40 mgKOH / g or less, and more preferably 30 mgKOH / g or less. The aromatic ring concentration derived from the raw material monomer of the aromatic dicarboxylic acid (a1-1) in the urethane resin (A) is preferably 1 mmol / g or more. Such an aromatic ring concentration is determined by calculating the number of moles of aromatic rings contained in 1 g of the urethane resin (A). The specific calculation method will be described later. From the viewpoints of improving the base material adhesion and deinking property of the obtained primer layer, the aromatic ring concentration is preferably 1.5 mmol / g or more, more preferably 2 mmol / g or more, and from the viewpoint of good film-forming property of the primer layer, it is preferably 6 mmol / g or less, and more preferably 5 mmol / g or less.

[0041] The value obtained by dividing the mass of the raw material monomer of the polyisocyanate (a2) contained in 1 g of the urethane resin (A) by the NCO equivalent weight of the raw material monomer of the polyisocyanate (a2) is preferably 1.0 to 6.0 mmol / g. When such a value is 1.0 mmol / g or more, the base material adhesion and deinking property of the obtained primer layer can be improved, it is more preferably 1.5 mmol / g or more, and further preferably 1.8 mmol / g or more. When it is 6.0 mmol / g or less, the film-forming property of the primer layer can be ensured, it is more preferably 5.0 mmol / g or less, and further preferably 4.0 mmol / g or less.

[0042] The weight-average molecular weight of the urethane resin (A) is preferably 10,000 to 100,000. From the viewpoint of resistance to blocking to the substrate and the hydrolysis stability of the resin, the weight-average molecular weight of the urethane resin (A) is preferably 20,000 or more, and more preferably 30,000 or more. Furthermore, from the viewpoint of lower viscosity during water dispersion and productivity, it is preferably 80,000 or less, and more preferably 60,000 or less.

[0043] In this invention, the weight-average molecular weight is the value measured by gel permeation chromatography (GPC) under the following conditions. Measuring apparatus: High-speed GPC apparatus (HLC-8220GPC manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were used in series. 1 x TSKgel G5000 (7.8 mm I.D. × 30 cm) 1 x TSKgel G4000 (7.8 mm I.D. × 30 cm) 1 x TSKgel G3000 (7.8 mm I.D. × 30 cm) 1 x TSKgel G2000 (7.8 mm I.D. × 30 cm) Detector: RI (differential refractometer) Column temperature: 40°C Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%) Standard sample: A calibration curve will be prepared using the standard polystyrene listed below.

[0044] [Standard Polystyrene] "TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation, "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[0045] The glass transition temperature of the urethane resin (A) is preferably 0 to 110°C.

[0046] <Aqueous Medium (B)> Examples of the aqueous medium (B) serving as the solvent for the urethane resin (A) include water, organic solvents miscible with water, and mixtures thereof. Examples of the water-miscible organic solvents include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; alkyl ethers of polyalkylene glycol; N-methyl-2-pyrrolidone and the like. In the present invention, only water may be used, a mixture of water and a water-miscible organic solvent may be used, or only a water-miscible organic solvent may be used. From the viewpoints of safety and environmental load, water alone or a mixture of water and a water-miscible organic solvent is preferred, and water alone is particularly preferred.

[0047] When dispersing the urethane resin (A) in the aqueous medium (B), a machine such as a homogenizer can be used as necessary.

[0048] The aqueous urethane resin composition of the present invention preferably contains urethane resin (A) in an amount of 5% to 50% by mass, and more preferably in an amount of 10% to 25% by mass, based on the total amount of the aqueous urethane resin composition. Furthermore, the aqueous medium (B) is preferably contained in an amount of 50% to 95% by mass, and more preferably in an amount of 75% to 90% by mass, based on the total amount of the urethane resin composition.

[0049] <Other Additives> The aqueous urethane resin composition of the present invention may contain various additives as needed, such as film-forming aids, crosslinking agents, curing accelerators, plasticizers, antistatic agents, waxes, light stabilizers, flow regulators, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, photocatalytic compounds, inorganic pigments, organic pigments, extender pigments, etc.

[0050] Among the additives, emulsifiers and leveling agents may cause a decrease in the durability of the resulting film, etc. Therefore, when high durability is required for the film, etc., it is preferable to use them in an amount of 5% by mass or less relative to the total amount of the aqueous urethane resin composition.

[0051] Furthermore, various crosslinking agents can be used in combination with the aqueous urethane resin composition of the present invention to form a film with excellent durability. Examples of crosslinking agents that can be used include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amino-based crosslinking agents, aziridine-based crosslinking agents, silane coupling agent-based crosslinking agents, carbodiimide-based crosslinking agents, and oxazolidine-based crosslinking agents. The amount of the crosslinking agent is preferably 30% by mass or less, and more preferably 20% by mass or less, relative to the total amount of the urethane resin (A), from the viewpoint of improving adhesion to the substrate and deinking properties. It is also preferable to mix the crosslinking agent with the aqueous urethane resin composition of the present invention immediately before coating or performing other applications.

[0052] (Primer layer) An anchor layer can be formed by coating a substrate with the aqueous urethane resin composition of the present invention. As described later, a vapor-deposited layer can be formed on the anchor layer. By providing the anchor layer, the adhesion of the vapor-deposited layer can be improved. Furthermore, the anchor layer can be easily removed by treatment with an alkaline solution. Since the anchor layer can be easily peeled off from the substrate, other layers such as the vapor-deposited layer, protective layer, and printed layer formed on top of the anchor layer can also be easily removed from the substrate. A detailed explanation of the method for removing the anchor layer will be given later.

[0053] The aqueous urethane resin composition of the present invention can be coated onto a substrate using known printing methods such as gravure printing and flexographic printing. Known printing methods include, in addition to the gravure printing and flexographic printing described above, any or a combination of two or more coating methods such as T-die coater, lip coater, knife coater, curtain, inkjet, bar coater, roll coater, spray coater, comma coater, reverse roll coater, direct gravure coater, reverse gravure coater, offset gravure coater, roll kiss coater, reverse kiss coater, kiss gravure coater, reverse kiss gravure coater, air doctor coater, wire bar coater, dip coater, blade coater, brush coater, die slot coater, offset printing press, screen printing press, etc. When printing, the aqueous solution is diluted with a diluent solvent, such as an alcohol-based organic solvent such as ethyl alcohol, isopropyl alcohol, or n-propyl alcohol, mixed with water, to a viscosity and concentration suitable for various printing methods such as gravure printing and flexographic printing, and supplied to each printing unit either alone or in combination.

[0054] Furthermore, the coating method for the aqueous urethane resin composition onto the substrate can be either an in-line coating method in which the aqueous urethane resin composition is applied during the substrate stretching process (e.g., biaxial stretching) and then the stretching process is carried out further, or an offline coating method in which the aqueous urethane resin composition is applied after the substrate stretching process (e.g., biaxial stretching) and dried to form a primer layer.

[0055] (Vaporized Layer) The laminate of the present invention has a vapor-deposited layer on top of the anchor layer, which is formed by vapor-depositing a metal or inorganic compound. The vapor-deposited layer may be obtained by vapor-depositing a metal such as aluminum, or metal compounds such as aluminum oxide (AlOx), silicon oxide (SiOx), zinc oxide, magnesium oxide, calcium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, and copper oxide may be used. These metals or inorganic compounds may be used individually or in combination of two or more.

[0056] The thickness of the vapor-deposited layer can be set appropriately depending on the application, but is preferably 10 to 300 nm, and more preferably 30 to 100 nm. A vapor-deposited layer thickness of 10 nm or more makes it easier to ensure sufficient continuity of the vapor-deposited layer, while a thickness of 300 nm or less sufficiently suppresses the occurrence of curling and cracking, making it easier to achieve sufficient gas barrier performance and flexibility. Furthermore, by setting the vapor-deposited layer thickness to 30 nm or more and 100 nm or less, the vapor-deposited layer becomes less prone to cracking, and sufficient water vapor barrier properties can be obtained even after bending.

[0057] Deposition of the vapor-deposited layer by vacuum deposition is preferable from the viewpoint of water vapor and oxygen gas barrier performance and film uniformity. Known deposition methods include vacuum deposition, sputtering, and chemical vapor deposition (CVD), but vacuum deposition is preferred due to its high deposition rate and productivity. Among vacuum deposition methods, electron beam heating is particularly effective because the deposition rate can be easily controlled by the irradiation area and electron beam current, and the heating and cooling of the deposition material can be performed in a short time.

[0058] (Protective Layer) The laminate of the present invention may have a protective layer on top of the vapor-deposited layer. The protective layer is provided for the purpose of protecting the vapor-deposited layer and improving the gas barrier function. The protective layer can be a protective layer provided on top of the vapor-deposited layer. For example, it can be formed by a known coating method such as gravure printing using a coating agent obtained by dissolving materials such as polyester, polyamide, chlorinated olefin, polyvinyl chloride, and polyurethane in various solvents. Furthermore, if it is desired to enhance the gas barrier function, it can be formed by coating with a known coating method using, for example, a coating agent containing a water-soluble polymer and one or more metal alkoxides and / or their hydrolysates, or a coating agent containing a water-soluble polymer and tin chloride. Examples of metal alkoxides include tetraethoxysilane and triisopropoxyaluminum. Examples of water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. Polyvinyl alcohol (hereinafter referred to as PVA) is particularly preferred because of its excellent gas barrier properties. Tin chloride can be stannous chloride (SnCl). ２ ), stannic chloride (SnCl ４ ), or mixtures thereof, can be used in anhydrous or hydrated form. Each of these components can be used individually or in combination of two or more to form a protective layer. Additives such as isocyanate compounds, silane coupling agents, dispersants, stabilizers, viscosity modifiers, and colorants may also be added, as long as they do not impair the gas barrier properties of the protective layer. The isocyanate compounds used in the protective layer have two or more isocyanate groups (NCO groups) in their molecule, and include monomers such as tolylene diisocyanate, triphenylmethane triisocyanate, and tetramethylxylene diisocyanate, as well as polymers or derivatives thereof.

[0059] The thickness of the equilayer should be at least 0.01 μm after drying, but a thickness of 50 μm or more makes the film more prone to cracking, so a range of 0.01 to 50 μm is preferable.

[0060] (Substrate A) The substrate A used in this invention is a plastic film, which is commonly used in plastic laminates. In particular, an olefin resin film is preferred, as it is expected to be feasible as a monomaterial.

[0061] (Olefin-based resin film) As the olefin-based resin film used in the present invention, a film made of a thermoplastic resin mainly composed of an olefin-based resin can be used. Specifically, examples of olefin-based resins include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and 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 polymethylpentene; as well as modified olefin-based resins obtained by modifying olefin resin with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or other unsaturated carboxylic acids.

[0062] Furthermore, it is preferable to use a film made from a material containing biomass-derived components as the film substrate. Biomass films are sold by various companies, and for example, sheets listed in the biomass certified product list provided by the Japan Organic Resources Association can be used.

[0063] A well-known example of a film made from biomass-derived ethylene glycol is derived from ethanol produced from biomass (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by conventionally known methods, such as a method that produces ethylene glycol via ethylene oxide from biomass ethanol. Alternatively, commercially available biomass ethylene glycol may be used; for example, the biomass ethylene glycol commercially available from India Glycol can be suitably used.

[0064] 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 ratio of 1 in 10¹² atoms, and this ratio does not change even in atmospheric carbon dioxide. Therefore, this ratio 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 (PDI) 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.

[0065] 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 containing polyethylene resins made from biomass-derived ethylene glycol are also known. The polyethylene resin is not particularly limited except that it uses the aforementioned biomass-derived ethylene glycol as part of its raw materials, and 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), and these can be used individually or in combination of two or more. 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 resins, medium-density polyethylene resins, and linear low-density polyethylene resins 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 the films to be damaged, such as by rubbing against each other, and linear low-density polyethylene resin having a density of 0.910 to 0.925 g / cm³ is more preferred.

[0066] 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.

[0067] The substrate A may have undergone 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.

[0068] The base material A can be manufactured from the resin described above by conventionally known film-forming methods such as extrusion, casting, T-die, cutting, and inflation. It may be an unstretched film, or, from the viewpoint of strength, dimensional stability, and heat resistance of the film (1), it may be stretched in one or two axes using a tenter method, tubular method, etc.

[0069] The base material A 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.

[0070] The film thickness of the substrate A 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.

[0071] When the base material A is used as a sealant layer, unstretched polypropylene film (CPP film) or linear low-density polyethylene resin film (LLDPE film) can be used.

[0072] (Laminate) The laminate of the present invention has an anchor layer and a vapor-deposited layer on a substrate A in that order. There may be other layers between the substrate A and the anchor layer, but from the viewpoint of peeling off layers that adhere to the substrate A, it is preferable that the substrate A and the anchor layer are in direct contact. The anchor layer and the vapor-deposited layer are in direct contact in order to improve the adhesion of the vapor-deposited layer to the substrate during normal use and to improve the removal of the vapor-deposited layer, etc., during recycling. The vapor-deposited layer of the present invention may have the above protective layer as appropriate. Furthermore, it is preferable to have a configuration in which one or more other layers selected from a printed layer, a barrier coat layer, an adhesive layer, a metal layer, another vapor-deposited layer, another substrate, etc. are placed on the vapor-deposited layer.

[0073] The present invention provides a laminate comprising a "substrate A / anchor layer / vapor-deposited layer" and other components such as a printed layer. While not limited to these embodiments, the following (1-A) configurations are preferred. (1-A) - Substrate A / anchor layer / vapor-deposited layer / protective layer / printed layer - Substrate A / anchor layer / vapor-deposited layer / protective layer / printed layer / overcoat layer - Substrate A / anchor layer / vapor-deposited layer / protective layer / overcoat layer

[0074] Furthermore, the laminate of the present invention includes not only a laminate consisting of a surface-printed type structure in which the printed layer is formed on the surface of the laminate, as in embodiment (1-A) above, but also a laminate consisting of a laminate type structure in which a coating film (various layers or films) is further formed on top of the printed layer. In other words, the laminate of the present invention is preferably a laminate with a laminate type structure in which another substrate is bonded (placed) to the surface on which the vapor-deposited layer of substrate A is arranged relative to the printed layer, and substrate A, anchor layer, vapor-deposited layer, and substrate B are laminated. As an example of a laminate consisting of a laminate type structure, the laminate of the embodiment described below can be cited. In the examples describing the laminate type structure below, the unstretched metal vapor-deposited film or transparent vapor-deposited stretched film may be a known unstretched metal vapor-deposited film or transparent vapor-deposited stretched film, but the laminate of the present invention described above, "substrate A / anchor layer / vapor-deposited layer" or "substrate A / anchor layer / vapor-deposited layer / protective layer", may also be used.

[0075] • (1-1) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Sealant film • (1-2) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Barrier coat layer / Adhesive layer 1 / Sealant film • (1-3) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Barrier coat layer / Printed layer / Adhesive layer 1 / Sealant film • (1-4) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Metal vapor deposition unstretched film • (1-5) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Metal vapor deposition stretched film • (1-6) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Substrate film 1 / Adhesive layer 2 / Sealant film • (1-7) (1-8) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Metal vapor deposition stretched film / Adhesive layer 2 / Sealant film (1-9) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Transparent vapor deposition stretched film / Adhesive layer 2 / Sealant film (1-10) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Substrate film 1 / Adhesive layer 2 / Metal layer / Adhesive layer 3 / Sealant film (1-11) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Substrate film 1 / Adhesive layer 3 / Sealant film

[0076] In the embodiments described above (1-1) to (1-11), an anchor layer and a vapor deposition layer may be coated on both sides of the film located in the intermediate layer. • (2-1) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Protective layer / Vapor deposition layer / Anchor layer / Base A / Anchor layer / Vapor deposition layer / Protective layer / Adhesive layer 2 / Sealant film

[0077] When substrate A is a sealant film, it is preferable to coat another substrate (substrate 1) with a known detachable primer. The anchor layer of the present invention may be provided as the primer layer. • (3-1) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-2) Transparent vapor deposition stretched film / Primer layer / Printing layer / Adhesive layer 1 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-3) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Base film 2 / Adhesive layer 2 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-4) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Metal vapor deposition stretched film / Adhesive layer 2 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-6) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-7) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Base film 2 / Adhesive layer 2 / Metal layer / Adhesive layer 3 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film) • (3-8) Base film 1 / Primer layer / Printing layer / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Base film 2 / Adhesive layer 3 / Protective layer / Vapor deposition layer / Anchor layer / Base material A (Sealant film)

[0078] As a laminate-type structure, it may be a laminate-type structure in which a coating film (various layers or films) is further formed on the printed layer by extrusion lamination. In other words, the laminate of the present invention also includes a laminate-type structure in which the extruded laminate layer is placed on the side opposite to the side on which the base material A is placed relative to the printed layer, and the base material A, anchor layer, vapor deposition layer, printed layer, and extruded laminate layer are laminated together. As an example of a laminate-type structure, the laminate described below can be cited. In the example describing the laminate-type structure below, base material film 1 corresponds to base material A as referred to in the present invention.

[0079] • (5-1) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Anchor layer for extrusion lamination / Extrusion laminate layer • (5-2) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Primer layer / Anchor layer for extrusion lamination / Extrusion laminate layer

[0080] In the embodiment of (5-2) above, the extruded laminate layer can be recovered and reused as resin without the printed layer attached. In embodiment of (5-2), both the base film 1 and the extruded laminate layer can be recovered and reused as resin without the printed layer attached. Although (5-1) to (5-2) above are configured with an "extruded laminate anchor layer" on top of the printed layer, the "extruded laminate layer" may be provided directly on the "printed layer" without providing an "extruded laminate anchor layer".

[0081] In addition to the configurations described in (5-1) to (5-2) above, other layers, such as a sealant layer, may be placed on the side opposite to the side on which the substrate A of the extruded laminate layer is provided. The configuration of the other layers is not limited to (5-1-1) to (5-1-deposition layer 4) below, and can be designed as appropriate according to the required characteristics. The following is an example of a configuration in which other layers are provided in the configuration of (5-1) above. Similar configurations are possible in (5-2) and (5-3) above. • (5-1-1) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Extruded laminate anchor layer / Extruded laminate layer / Sealant film • (5-1-2) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Extruded laminate anchor layer / Extruded laminate layer / Vapor deposition layer / Sealant film • (5-1-3) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Extruded laminate anchor layer / Extruded laminate layer / Primer layer / Sealant film • (5-1-4) Substrate A / Anchor layer / Vapor deposition layer / Protective layer / Printed layer / Extruded laminate anchor layer / Extruded laminate layer / Primer layer / Vapor deposition layer / Sealant film

[0082] When manufacturing the laminates according to each of the above embodiments, if the anchor layer of the present invention or a known primer layer is formed on each of the films, base material A, base material film 1, base material film 2, metal vapor-deposited stretched film, and transparent vapor-deposited stretched film, as explained in the (anchor layer) section above, the primer layer may be formed by an in-line coating method in which the aqueous urethane resin composition is applied during the film stretching process and then the stretching process is carried out further, or the primer layer may be formed by an offline coating method in which the aqueous urethane resin composition is applied after the film stretching process and dried to form the primer layer.

[0083] The above descriptions illustrate various aspects of the laminate structure, but it is not limited to these. The following describes each layer constituting the laminate.

[0084] (Printed Layer) The printed layer is a layer on which designs such as characters, figures, symbols, and other desired patterns are printed. There are no particular limitations on the printing method or printing ink, and known printing methods and printing inks can be used. Printing inks used for films used as the substrate are often those produced using gravure printing, flexographic printing, lithographic offset printing, and inkjet recording printing methods. Printing inks that combine these printing methods with methods that cure using active energy rays such as ultraviolet (UV), LED, or electron beam (EB), or methods that cure with heat are also used. Depending on the solvent used, they may also be referred to as water-based inks or organic solvent-based inks.

[0085] 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.

[0086] Furthermore, the printing plates can be selected appropriately according to the desired design. In addition to plates for letters, figures, symbols, and other desired patterns, solid color plates can also be used.

[0087] The location where the printed layer using these inks is provided is preferably not between the substrate and the primer layer, which is a film of the film-forming composition of the present invention, but directly on the primer layer, or on top of another layer provided on the primer layer. The ink may contain a resin, a colorant, and a solvent as essential components, or it may be a so-called clear ink that contains a resin and a solvent and substantially does not contain a colorant. The liquid ink most commonly used for printing on film will be described below.

[0088] The binder resin used in liquid inks is not particularly limited. For example, in the case of organic solvent-based inks, examples include cellulose resins (nitrocellulose, cellulose acetate propionate, cellulose acetate butyronate), polyurethane resins, polyamide resins, polyvinyl butyral resins, vinyl chloride vinyl acetate copolymer resins, acrylic resins, polyester resins, styrene resins, styrene-maleic acid resins, maleic acid resins, vinyl chloride-acrylic copolymer resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyvinyl chloride resins, chlorinated polypropylene resins, epoxy resins, alkyd resins, rosin resins, rosin-modified maleic acid resins, ketone resins, cyclized rubber, chlorinated rubber, petroleum resins, etc., and one or more of these can be used in combination. Preferably, it is at least one or more selected from cellulose resins (nitrocellulose, cellulose acetate propionate, cellulose acetate butyronate), polyurethane resins, polyamide resins, polyvinyl butyral resins, and vinyl chloride vinyl acetate copolymer resins.

[0089] Furthermore, in the case of water-based inks, examples include acrylic resin emulsions, urethane resin emulsions, polyester resin emulsions, etc., in which acrylic resin, urethane resin, polyester resin, etc., are dissolved or dispersed in water or a water-containing aqueous solvent.

[0090] Examples of colorants used in liquid 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.

[0091] Liquid inks for film printing are often organic solvent-based inks. Preferably, the organic solvent used does 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.

[0092] (Overcoat layer) In the ink used for the printing layer, a clear ink containing resin and solvent and substantially free of colorants can also be used as an overprint varnish (sometimes called OP varnish) or coating agent. When used as an overprint varnish or coating agent, a solid color is usually printed on the printing layer to protect it. Overprint varnishes and coating agents with various functional properties can also be used. For example, overprint varnishes and coating agents that impart functionality such as scratch resistance, oil resistance, water resistance, heat resistance, or food contact material can be used.

[0093] (Adhesive Layer) The above adhesive layer can be any known adhesive for film lamination. Furthermore, when laminating by extrusion lamination, any known anchor coating agent for extrusion lamination can be used as an adhesive aid. Using gas barrier materials as these adhesives and anchor coating agents allows for the creation of laminates with particularly excellent barrier properties. A particularly preferred 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 / day / atm or less, or water vapor barrier property of 120 g / m² ２ This refers to products that satisfy at least one of the following conditions: / day or less. Examples of commercially available products include the "PASLIM" series such as PASLIM VM001 and PASLIM J350X manufactured by DIC Corporation, and "MAXIEVE" manufactured by Mitsubishi Gas Chemical Company. Known thermoplastic resins can be used as the extruded laminate layer. Examples of thermoplastic resins include polyethylene resins and polyolefin resins such as polypropylene resins, but are not limited to these materials. Various known anchor coating agents can be used as the anchor layer for extruded lamination. For example, isocyanate-based and amine polymer-based materials can be used, but are not limited to these materials. The "anchor layer for extruded lamination" may also be formed using the aqueous urethane resin composition of the present invention. By forming the "anchor layer for extruded lamination" using the aqueous urethane resin composition of the present invention, adhesion to the extruded laminate layer can be improved, and the peelability of the extruded laminate layer during the peeling process can be improved. (Barrier Coat Layer) The barrier coat layer can be obtained by applying a gas barrier coating agent containing a known gas barrier resin with high gas barrier properties to form a coating film. As an example of the gas barrier resin, a gas barrier coating agent containing a vinyl alcohol-based polymer and an aqueous solvent can be mentioned.

[0094] Specific examples of vinyl alcohol polymers 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.

[0095] The gas barrier coating agent may further contain additives such as layered inorganic compounds, crosslinking agents that react with the functional groups of vinyl alcohol polymers, adhesion enhancers, inorganic fillers, defoamers, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, and leveling agents.

[0096] Examples of layered inorganic compounds include natural smectite such as montmorillonite, synthetic smectite, natural mica, synthetic mica, hydrotalcite, and talc, as well as lipophilic treated smectite and lipophilic synthetic mica obtained by organic treatment of these compounds. The gas barrier properties of the gas barrier resin layer are improved by using layered inorganic compounds. The amount of layered inorganic compound blended is preferably 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of vinyl alcohol polymer.

[0097] Examples of crosslinking agents include: aldehydes such as formaldehyde, oxalaldehyde, and glutaraldehyde; acetals such as diacetalized glutaraldehyde; aliphatic polyisocyanates represented by hexamethylene diisocyanate and its derivatives (adduct, nurate, burette, etc.); aromatic aliphatic polyisocyanates represented by xylylene diisocyanate and its derivatives; aromatic polyisocyanates represented by toluene diisocyanate and its derivatives; isocyanates such as urethane prepolymers which are reaction products of these isocyanates with polyols; epoxy compounds; organometallic compounds of titanium, silicon, aluminum, zirconium, boron, etc. with alkoxides, etc.; methylolureas such as methylolurea and methylolmelamine; polyacrylic acid polymers, maleic anhydride polymers, etc. Examples include carboxyl group-containing polymers; carbodiimides such as p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), and cyclohexane-1,4-bis(methylene-t-butylcarbodiimide); hydrazine compounds such as methylenedihydrazine, ethylenedihydrazine, propylenedihydrazine, butylenedihydrazine, oxalate dihydrazide, malonic acid dihydrazide, succinate dihydrazide, glutarate dihydrazide, adipic acid dihydrazide, and sebacate dihydrazide; hydrazide compounds such as adipic acid dihydrazide, carbodihydrazide, and polyhydrazide; boric acid; and titanium lactate. For isocyanates, blocked isocyanates using known blocking agents may be used, or emulsion-type isocyanates may be used.

[0098] The amount of crosslinking agent is adjusted as appropriate, but one example is 0.5 to 30 parts by mass per 100 parts by mass of vinyl alcohol polymer.

[0099] The amount of gas barrier coating agent applied is adjusted as appropriate depending on the desired degree of gas barrier properties, but as an example, it is 0.1 g / m² to 5.0 g / m², more preferably 0.3 g / m² to 2.0 g / m².

[0100] Commercially available gas barrier coating agents can also be used, 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.

[0101] <Applications of the Laminate> The laminate of the present invention can be applied to various molded products such as electronic equipment, building materials, textiles and leather, home appliances, vehicles such as cars and airplanes, furniture, office supplies, play equipment, sports equipment, or molded parts thereof. The laminate of the present invention can also be applied to packaging materials (more specifically, multilayer packaging materials). It can be used as a multilayer packaging material. When used as a multilayer packaging material, the layer configuration may change depending on the contents, usage environment, and usage form. The packaging of the present invention may also be appropriately provided with an easy-open treatment and resealing means. When used as a packaging material, for example, after filling the contents through the opening, the opening is heat-sealed to manufacture a product using the packaging material formed from the laminate of the present invention. The applications of the packaging material are not particularly limited, but it can be suitably used as a packaging material for food, pharmaceuticals, sanitary products, cosmetics, electronic materials, building materials, industrial materials, etc.

[0102] For example, in the present invention, a laminate having a sealant layer can be used as a packaging material. The sealant layer surfaces of the laminate are placed opposite each other, and then the peripheral edges are heat-sealed to form a bag. As for the bag-making method, the laminate of the present invention can be folded or placed so that the inner layer surfaces (sealant layer surfaces) face each other, and the peripheral edges can be heat-sealed in various forms, such as side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, gusset seal type, pleated seal type, flat-bottom seal type, square-bottom seal type, gusset type, and other heat-seal types. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage method. Self-standing packaging materials (standing pouches) are also possible. As for the heat-sealing method, known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal can be used.

[0103] If the base material A in the laminate of the present invention does not function as a sealant layer that will be used as a heat-sealing area when forming the packaging material, an additional sealant layer may be added. The sealant layer may be formed by bonding an additional base material with a laminating adhesive or by an extrusion lamination method. Alternatively, it may be formed by coating it with a heat sealant or a cold sealant.

[0104] Products using the packaging material of the present invention are manufactured by filling the packaging material with contents through its opening and then heat-sealing the opening. Examples of contents that can be filled include, for example, food products such as rice crackers, bean snacks, nuts, biscuits / cookies, wafers, marshmallows, pies, semi-baked cakes, candies, and snack foods; staple foods 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; processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef; and fish ham. Examples of processed seafood products include sausages, processed seafood products, fish cakes, seaweed, preserved foods, dried bonito flakes, salted seafood, smoked salmon, and spicy cod roe; 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.

[0105] 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.

[0106] <Characteristics of the Laminate> The laminate of the present invention has an anchor layer containing a specific urethane resin, and therefore exhibits good adhesion to the substrate, and the laminate of the present invention has excellent adhesion between the substrate and the vapor-deposited layer. Furthermore, the anchor layer of the laminate of the present invention can be easily detached by using an alkaline solution, and the substrate and vapor-deposited layer can be easily peeled off. However, under normal operating temperature conditions, the anchor layer of the laminate of the present invention will not peel off even if an alkaline solution is applied. Therefore, under normal operating temperature conditions, even if an alkaline solution happens to adhere to the laminate, it can be used with peace of mind without worrying about peeling. The laminate having an anchor layer formed with the aqueous urethane resin composition of the present invention allows for easy detachment of the primer layer by applying an alkaline solution, and easy peeling of the substrate and vapor-deposited layer, not only for laminates with a surface-printed structure but also for laminates with a laminated structure. Furthermore, when the aqueous urethane resin composition contains a crosslinking agent, the anchor layer formed using the aqueous urethane resin composition containing the crosslinking agent exhibits excellent film strength and good film-forming properties, while the anchor layer formed using the aqueous urethane resin composition of the present invention can maintain the high peeling performance that is the objective of the present invention, even if it contains a crosslinking agent. In other words, the laminate of the present invention manufactured using a crosslinking agent can be made to have excellent film-forming properties and delamination properties.

[0107] (Method for removing the primer layer from substrate A) The primer layer is removed from the substrate by immersion in an alkaline solution. In the alkaline aqueous solution used to remove the primer layer in this invention, there are no particular restrictions on the alkaline substance used, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or calcium hydroxide (Ca(OH)). ２ Examples include ammonia, etc. Preferably, NaOH or KOH. As for the method of producing an alkaline aqueous solution, NaOH, KOH, ammonia, etc. can be uniformly dissolved or dispersed in water and adjusted to the specified concentration or pH as appropriate.

[0108] <Method for removing the anchor layer in laminates with surface printing configuration> Typically, the conditions for removing the anchor layer include immersing the laminate in an alkaline aqueous solution with a pH of 11 or higher or a concentration of 0.5 to 3.0% by mass at a temperature of 10°C to 100°C for 30 minutes, followed by washing and drying to remove 90% or more of the primer layer. The pH is preferably 11.0 or higher, more preferably 13.0 or higher. The concentration is preferably a 0.5 to 3.0% by mass aqueous solution, more preferably a 1.0 to 2.5% by mass aqueous solution. The immersion temperature is preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 80°C or lower. On the other hand, in order to prevent the removal of the anchor layer and, consequently, the removal of the printed layer, when an alkaline substance unintentionally adheres to the laminate, it is necessary that the anchor layer is not removed at low temperatures. Therefore, the immersion temperature is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher. The immersion time is within 60 minutes, more preferably within 30 minutes, and even more preferably within 20 minutes. The removal rate of the anchor layer after subsequent washing and drying is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0109] <Method for removing the anchor layer in laminated structures with a laminated structure> In the case of laminated structures such as the one described in (1-1) above, the anchor layer is sandwiched between plastic films, and it takes a considerable amount of time for the alkaline aqueous solution to reach the anchor layer. Therefore, the immersion time is required to be longer than in the one described in (1-A), but it is preferable that the delamination proceeds in a short time. The immersion time is preferably within 24 hours, more preferably within 12 hours, and even more preferably within 6 hours.

[0110] As described above, the anchor layer can be detached by immersing the laminate in an alkaline solution. In other words, according to the present invention, recycled substrate A can be obtained by treating the laminate with an alkaline solution and detaching the printed layer together with the anchor layer from substrate A. The same applies even if the laminate has a laminate-type structure, according to the present invention, recycled substrate A, or recycled substrate A and recycled substrate B or sealant film can be obtained by treating the laminate with an alkaline solution and detaching the vapor-deposited layer, printed layer and / or substrate B together with the anchor layer from substrate A.

[0111] (Recycling method, recycled plastic) The laminate of the present invention can also be recycled using known processing methods for recycling waste plastics.

[0112] The recycled plastic of the present invention can be obtained by processing methods for recycling known waste plastics. An example of a processing method is shown. Of course, the present invention is not limited to this, and various known recycled plastic processing methods can be applied.

[0113] As an example of a processing method, a method for producing recycled plastic is provided, comprising the steps of crushing the gas barrier laminate of the present invention, melting and kneading the crushed pieces, and pelletizing the melted and kneaded mixture. The crusher used in the step of crushing the gas barrier laminate of the present invention can be any known pulverizer and is not particularly limited. The film pieces after crushing are physically blended with melt kneading, solvent cast blend, latex blend, polymer complex, etc. Melt kneading is particularly common. Examples of kneading equipment include tumblers, Henschel mixers, rotary mixers, super mixers, ribbon tumblers, V blenders, etc. After melt kneading with such kneading equipment, the material is pelletized. For melt kneading pelletization, a single-screw or multi-screw extruder is generally used, and the film pieces may be fed in as is, or after being compressed and reduced in volume by heating or non-heating. In addition to these extruders, Banbury mixers, rollers, co-kneaders, blast mills, and plastic benders / brautographs can also be used, and these are operated batch or continuously. Alternatively, instead of melt-kneading, the material can be used as a molding resin and melt-kneaded in the heating cylinder of the molding machine.

[0114] Furthermore, as an example of a processing method, a method for producing recycled plastic is provided, which includes the steps of: crushing the gas barrier laminate of the present invention as necessary; immersing the laminate in a release solution to separate and detach each layer; recovering each separated layer; melting and kneading the recovered crushed pieces; and pelletizing the melted and kneaded mixture.

[0115] As described above, the crusher used in the process of crushing the gas barrier laminate of the present invention can be any known pulverizer and is not particularly limited. The film pieces after crushing are immersed in a release solution to separate and detach the laminate into its individual layers. The separation and detachment method (also simply called the detachment method) is a method of immersing the gas barrier laminate of the present invention in a release solution (detachment treatment solution) to detach the other layers provided on the substrate from the substrate. Detachment refers to the separation of the substrate from the other layers by the detachment layer dissolving or swelling and peeling off due to the detachment treatment solution.

[0116] (Desorption treatment liquid) The desorption treatment liquid can be any liquid that swells and dissolves the adhesive layer, printed layer, etc. in the gas barrier laminate of the present invention, and can be appropriately selected considering the ease of desorption of the desorption layer described later. Examples of such desorption liquids include water, alkaline solutions, and acidic aqueous solutions. From the viewpoint of desorption of the adhesive layer and printed layer materials commonly used in packaging materials, the desorption treatment liquid is preferably an alkaline solution containing an inorganic base.

[0117] (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.

[0118] (Surfactants) The desorption treatment liquid may contain surfactants. The surfactant is not particularly limited and known surfactants 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. When a surfactant is added, the amount added is preferably in the range of 0.001 to 2% by mass of the total amount of the desorption treatment liquid, more preferably 0.001 to 1.5% by mass, and even more preferably 0.01 to 1% by mass.

[0119] In addition, it may contain water-soluble organic solvents, non-water-soluble organic solvents, defoaming agents, etc.

[0120] (Liquid Temperature) The liquid temperature of the desorption treatment solution is not particularly limited as long as it can be kept in a liquid state, but it is generally preferable to perform the treatment at a liquid 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 liquid 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 75°C or higher is preferable. Furthermore, it is preferable to immerse the target printed material or laminate in a treatment tank, for example, while the desorption treatment solution 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 heat rays, infrared rays, and microwaves can be used. For ultrasonic vibration, for example, a method can be used in which an ultrasonic transducer is attached to the treatment tank and ultrasonic vibration is applied to the hot water or alkaline solution.

[0121] (Agitation) While agitation is not mandatory when immersing printed materials or laminates in the desorption solution, it is optional. However, agitation allows for more efficient swelling. It is preferable to maintain an agitation speed that does not easily cause foaming, even without the addition of an antifoaming agent.

[0122] 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.

[0123] The immersion time for the printed material or laminate in the desorption solution depends on the composition of the printed material or laminate, but is generally in the range of 2 minutes to 48 hours. In the printed material or 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.

[0124] 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.

[0125] 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 more preferable to include a step of fragmenting the printed material or laminate by cutting or crushing.

[0126] The method for crushing the plastic film is not particularly limited and can be carried out by known methods. Crushing may be performed in an air atmosphere without the presence of solvents or other liquids, or in water or a washing solution. When crushing is performed in an air atmosphere, a dry crusher can be used. When crushing is performed in water or a washing solution, a wet crusher that can perform crushing and pumping simultaneously can be used. When a wet crusher is used, the plastic film can be crushed efficiently, and laminated plastic films can be peeled into individual layers.

[0127] 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.

[0128] Furthermore, it is preferable to perform a final wash by stirring the recovered substrate in a rinsing solution to clean away any residual ink, adhesive, or other detached material that has re-adhered to the plastic film that has been detached into a single layer. Removing any ink fragments remaining on the film surface significantly improves the quality of the recycled pellets. The rinsing solution is not particularly limited, and the aforementioned detachment treatment solution can be used as is, but it is preferable that it contains an appropriate amount of organic solvent. As for the organic solvent, it is preferable that it contains, for example, one or more types of water-soluble alcohols or water-soluble solvents with a flash point of 21°C or higher, and it is preferable that the washing solution contains a large amount of so-called water-soluble solvents including alcohols. Specifically, it is preferable that the amount of water-soluble solvent be 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, and 95% by mass or more. The equipment and method of stirring when 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 agitate the cleaning solution inside the container, devices equipped with a device that generates ultrasonic waves, devices that can shake the container as a whole, wet crushers, and kneaders.

[0129] (Recovery and reuse of desorption treatment liquid) The desorption treatment liquid used in the desorption treatment process can be recycled after being supplied to one or more recycling machines selected from a filter, centrifuge, or ultrafilter to remove solid matter. The same applies when water, rinsing liquid, etc. are used. It is also possible to operate the reuse process for water, desorption treatment liquid, rinsing liquid, etc., continuously while wet crushing is being performed, and separate solid matter from water, washing liquid, and rinsing liquid.

[0130] (Drying of separated plastic material) The recovered material (film pieces) of the separated and recovered base material is dried by one or more methods selected from vacuum heating drying, hot air drying, and pressure compression drying in order to remove residual moisture. As a pretreatment for producing recycled pellets as described later, briquettes may be produced after or during the drying of the recovered film pieces 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. When the plastic 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 material that makes up the crushed material, but a higher density is preferable as 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.

[0131] The pellets made primarily from recycled plastic of the present invention can achieve their maximum effect when recycled into unoriented polyolefin films or molded products by injection molding, etc. The method for recycling into unoriented polyolefin films is not particularly limited and can be obtained by known film manufacturing methods. For example, a melt-kneading method using a general mixer such as a single-screw extruder, twin-screw extruder, or multi-screw extruder, or a method in which each component is dissolved or dispersed and mixed, and then the solvent is heated and removed can be used. Considering workability, it is particularly preferable to use a single-screw extruder or a twin-screw extruder. When using a single-screw extruder, it is possible to use a full-flight screw, a screw with a mixing element, a barrier-flight screw, a fluted screw, etc., without any particular limitations. For twin-screw mixers, there is no particular limitation on the type of extruder, such as a co-rotating twin-screw extruder or a twin-screw extruder that rotates in opposite directions, and the screw shape is also not particularly limited to a full-flight screw or a kneading disc type. Alternatively, a method may be used in which the material is melted using a single-screw extruder or a twin-screw extruder, and then a film is formed using a T-die via a feed block or multi-manifold. Furthermore, the recycled film can be subjected to surface modification treatment as needed to improve its suitability for subsequent processes. For example, surface modification treatment can be applied to the surface that comes into contact with other substrates to improve printability when using a single film or to improve lamination suitability when using a laminate. Suitable surface modification treatments include methods that oxidize the film surface to express functional groups, such as corona discharge treatment, plasma treatment, and flame treatment, as well as wet processes such as coating with an easily adhesive layer.

[0132] In addition, similar to pellets made primarily from virgin plastic, the material may be molded using conventional molding methods other than film formation, such as injection molding, extrusion molding, vacuum molding, pressure molding, and blow molding, and used as a molded body for various applications. For example, it can be used as a film, sheet, or fiber in addition to everyday household goods, stationery, toys, sporting goods, home appliances, and automobile parts. If there are no hygiene concerns, it can also be used in medical devices, food containers, and food packaging.

[0133] The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Also, "%" in the compositions of the following examples means "mass percent".

[0134] <Aromatic ring concentration (moles / g) derived from raw material monomers of aromatic dicarboxylic acid (a1-1)> The number of moles of aromatic rings contained in 1 g of urethane resin is calculated. This can be calculated based on the raw materials used in the synthesis of aromatic polyester polyol and their proportions. It is determined by dividing the mass of raw material monomers of aromatic dicarboxylic acid (a1-1) contained in 1 g of urethane resin by the molecular weight of the raw material monomers of aromatic dicarboxylic acid (a1-1).

[0135] <Ester bond group concentration (moles / g)> The number of moles of ester bond groups contained in 1 g of urethane resin is calculated. This can be calculated based on the raw materials used in the synthesis of aromatic polyester polyol and their proportions. First, the concentration of ester bond groups in 1 g of aromatic polyester polyol (a1) is calculated using the following formula (I). Formula (I) takes into account dehydration due to ester formation.

[0136] In formula (I), a represents the number of moles of carboxylic acid in 1 g of aromatic polyester polyol (a1). After determining the concentration of ester bond groups in 1 g of aromatic polyester polyol (a1), the product of the concentration of ester bond groups in 1 g of aromatic polyester polyol (a1) and the proportion of aromatic polyester polyol (a1) in 1 g of urethane resin is calculated to determine the concentration of ester bond groups in 1 g of urethane resin.

[0137] <Acid Value (mgKOH / g)> This value is determined by the number of mg of KOH required when the COOH groups contained in 1 g of urethane resin are titrated using the potassium hydroxide method.

[0138] <Urethane + Urea functional group concentration (mol / g)> This is calculated by dividing the mass of the raw material monomer of polyisocyanate (a2) contained in 1 g of urethane resin by the NCO equivalent weight of the raw material monomer of polyisocyanate (a2).

[0139] <Weight-average molecular weight> The weight-average molecular weight is measured by gel permeation chromatography (GPC).

[0140] <Glass transition temperature (°C)> The glass transition temperature is measured using a differential scanning calorimeter.

[0141] <Polyol hydroxyl value> Measured in accordance with the method described in JIS K1557-1.

[0142] (Polyols) The composition and properties of polyols 1 to 7 used in the examples and comparative examples are shown in Table 1 below. In Table 1, TPA represents terephthalic acid, IPA represents isophthalic acid, AA represents adipic acid, EG represents ethylene glycol, DEG represents diethylene glycol, and 14BG represents 1,4-butylene glycol. For example, polyol 2 in Table 1 indicates that an aromatic polyester polyol was prepared by mixing and reacting terephthalic acid in the proportions of 0.32 g, isophthalic acid in the proportions of 0.32 g, ethylene glycol in the proportions of 0.13 g and diethylene glycol in the proportions of 0.23 g.

[0143]

[0144] (Urethane Resin) Urethane resin 1 was synthesized as follows: In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, 0.74 g of polyol 2, 0.20 g of isophorone diisocyanate, and 0.06 g of 2,2'-dimethylolpropionic acid were charged in these proportions, and the mixture was reacted at 75°C for 8 hours under a nitrogen atmosphere to obtain urethane resin 1. The composition and physical properties of urethane resin 1 are shown in Table 2 below.

[0145] Polyurethane resins 2 to 9 were prepared by the same method as below, except that the composition of polyurethane resin 1 was changed as shown in Table 2 or Table 3. The compositions and physical properties of polyurethane resins 2 to 9 are shown in Tables 2 and 3.

[0146]

[0147]

[0148] The aromatic ring concentrations listed in Table 1 were determined as follows. Urethane resin 1 is used as an example. First, the aromatic ring concentration in 1 g of polyol 2 is calculated. • Determine the mass ratio of the raw material monomers of the aromatic dicarboxylic acid (a1-1) containing the aromatic ring / the molecular weight of that monomer. If there are multiple raw material monomers for the aromatic dicarboxylic acid (a1-1), calculate their sum. • {0.32 (terephthalic acid content of polyol 2) / 166 (molecular weight of terephthalic acid) + 0.32 (isophthalic acid content of polyol 2) / 166 (molecular weight of isophthalic acid)} × 1000 = 3.8 mmol / g

[0149] Next, calculate the aromatic ring concentration in 1 g of urethane resin by multiplying the aromatic ring concentration in 1 g of aromatic polyester polyol (a1) by the proportion of aromatic polyester polyol (a1) in 1 g of urethane resin. 3.84 (aromatic ring concentration of polyol 2) × 0.74 (polyol 2 content in urethane resin 1) = 2.8 mmol / g

[0150] The ester bond group concentrations listed in Table 1 were determined as follows. Urethane resin 1 is used as an example. First, the ester bond group concentration in 1 g of polyol 2 is calculated. If a is the number of moles of carboxylic acid in 1 g of aromatic polyester polyol (a1), then a can be calculated as follows: a = {0.32 (terephthalic acid content of polyol 2) / 166 (molecular weight of terephthalic acid) + 0.32 (isophthalic acid content of polyol 2) / 166 (molecular weight of isophthalic acid)} × 2 (the raw material monomer of aromatic dicarboxylic acid (a1-1) contains two carboxylic acids) = 0.00771 Next, the calculated a is substituted into the above formula (I). {a / (1 - a × 18 (amount of water to be dehydrated))} × 1000 = 8.9 mmol / g

[0151] Next, calculate the concentration of ester groups in 1 g of urethane resin by multiplying the concentration of ester groups in 1 g of aromatic polyester polyol (a1) by the proportion of aromatic polyester polyol (a1) in 1 g of urethane resin. 8.9 (concentration of ester groups in polyol 2) × 0.74 (content of polyol 2 in urethane resin 1) = 6.6 mmol / g

[0152] The urethane + urea functional group concentrations listed in Table 1 were determined as follows. Urethane resin 1 is used as an example. 0.2 (content of isophorone diisocyanate in urethane resin 1) ÷ 111.15 (NCO equivalent weight of isophorone diisocyanate) = 1.8 mmol / g Here, the NCO equivalent weight of isophorone diisocyanate is calculated by dividing the molecular weight of isophorone diisocyanate by 2, so 222.3 ÷ 2 = 111.15.

[0153] The laminate 1 used in Example 1 was prepared as follows. An OPP base film (Futamura Chemical Co., Ltd.'s "FOR 20μm") was used as the base film 1. A urethane resin 1 was used as the anchor coat layer, and a crosslinking agent was included in the aqueous urethane resin composition. The anchor coat layer containing the crosslinking agent was prepared as follows. Using urethane resin 1, 9 parts of Nisshinbo Chemical Co., Ltd.'s "Carbodilite SV-02" were mixed with 100 parts of the urethane resin, and then diluted with isopropyl alcohol (IPA) to a solid content of 10%. The aqueous urethane resin composition obtained above was printed on the base film 1, which had been corona discharged on one side, using a gravure printing press (DIC Engineering Co., Ltd.) equipped with a gravure plate having a plate depth of 22 μm. After that, it was dried at 100°C for 10 minutes, and then left at room temperature for more than one day. The vapor-deposited layer was prepared as follows. On the fabricated anchor layer, a 15 nm thick layer of aluminum oxide was deposited using a vacuum deposition apparatus employing electron beam heating. Similarly, a silicon oxide (SiOx) deposition layer was deposited. Similarly, layers of aluminum oxide (AlOx) and silicon oxide (SiOx) were deposited. The ink layer was prepared as follows: The laminating ink "Finato BM (manufactured by DIC Corporation)" was diluted with a mixed organic solvent in the same ratio as the ink, and diluted for 16 seconds using a Zahn cup No. 3 manufactured by Rigosha. This was then printed using a gravure printing press (manufactured by DIC Engineering Corporation) equipped with a gravure plate having a plate depth of 22 μm. The resulting laminate 1 was aged at 40°C for 5 days. The composition of laminate 1 is shown in the table below.

[0154] Laminates 2 to 31 were fabricated using the same method, except that the composition of laminate 1 was changed as shown in Tables 4 to 7 below. The compositions of laminates 2 to 31 are shown in Tables 4 to 7.

[0155] Comparative laminates 1 to 19 were fabricated using the same method, except that the configuration of laminate 1 was changed as shown in Tables 8 to 10 below. The configurations of comparative laminates 1 to 19 are shown in Tables 8 to 10.

[0156] In the table, PU resin refers to polyurethane resin. If the base film 1 is PET, the base film refers to "E5102 12μm" manufactured by Toyobo Co., Ltd. If it is OPP (biaxially oriented polypropylene), the base film refers to "FOR 20μm" manufactured by Futamura Chemical Co., Ltd. If it is CPP (unoriented polypropylene), the base film refers to "P1128 25μm" manufactured by Toyobo Co., Ltd. The crosslinking agent "BU3100" refers to "Bayhydrur Ultra 3100" manufactured by Covestro. The primer layer containing the "BU3100" crosslinking agent was prepared by mixing 3 parts of "Bayhydrur Ultra 3100" manufactured by Covestro with 100 parts of urethane resin, and then diluting it with water to a solid content of 10%. If the anchor coat layer does not contain a crosslinking agent, the primer layer was formed using an aqueous urethane resin composition diluted with isopropyl alcohol (IPA) to a solid content of 10% in the urethane resin. The method for applying the aqueous urethane resin composition using a gravure printing machine to form the primer layer is as described above in the preparation of laminate 1. When the ink layer is ink 1, it is indicated as "Finato BM R507 primary color blue". The method for forming the ink layer is as described above in the preparation of laminate 1. When the vapor deposition layer is transparent vapor deposition 1, it is indicated as aluminum oxide (AlOx), when it is transparent vapor deposition 2, it is indicated as silicon oxide (SiOx), and when it is transparent vapor deposition 3, it is indicated as aluminum oxide (AlOx) and silicon oxide (SiOx).

[0157] (Examples and Comparative Examples) The following tests were performed on laminates 1 to 31 and comparative laminates 1 to 19.

[0158] <Adhesion Evaluation> After leaving the prepared printed material for one day, cellophane tape (Nichiban, 12 mm wide) was applied to the printed surface. The appearance of the printed ink layer (printed film) was visually observed when the cellophane tape was rapidly peeled off, and the film adhesion was evaluated according to the following criteria.

[0159] (Evaluation Criteria) 5: The printed film did not peel off at all. 4: The printed film peeled off slightly, but 80% or more remained on the film. 3: 50% to less than 80% of the printed film remained on the film. 2: 30% to less than 50% of the printed film remained on the film. 1: Less than 30% of the printed film remained on the film.

[0160] <Deinking Performance Evaluation> Test pieces cut to a size of 20 mm x 20 mm were immersed in a 1% by mass aqueous solution of sodium hydroxide at a liquid temperature of 85°C and stirred with a stirrer. After stirring, the peeling state was checked, and then the printed material was rubbed with a finger to check if the coating could be peeled off by rubbing. The peelability of the ink coating under the above conditions was evaluated according to the evaluation criteria below. (Evaluation Criteria) 5: Peeling of the ink coating was confirmed with stirring within 5 minutes. Completely removed by rubbing 4: Peeling of the ink coating was confirmed with stirring for 15 minutes. Completely removed by rubbing 3: Peeling of the ink coating was not confirmed with stirring for 15 minutes. Completely removed by rubbing 2: Peeling of the ink coating was not confirmed with stirring for 60 minutes. Partially removed by rubbing 1: Peeling of the ink coating was not confirmed with stirring for 60 minutes. Detachment was not confirmed even after rubbing. While a level of 4 or higher is preferable for practical purposes, a level of 3 is also sufficient to contribute to recycling, therefore, a level of 3 or higher can be considered acceptable.

[0161] <Barrier property evaluation> The laminates of the examples and comparative examples were adjusted to a size of 10 cm x 10 cm, and the oxygen permeability was measured using an OX-TRAN2 / 21 (Mokon Co., Ltd.: oxygen permeability measuring device) in accordance with JIS-K7126 (isobaric method) under an atmosphere of 23°C and 70% RH (units are cc / m2 / day / atm). RH represents humidity.

[0162]

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169] As is clear from the results of the above examples, the laminate having an anchor coat layer formed with the aqueous urethane resin composition of the present invention exhibits excellent adhesion to the vapor-deposited layer and excellent oxygen barrier properties. Furthermore, the anchor coat layer could be easily removed by using an alkaline solution. On the other hand, the primer layer was not removed by the alkaline solution under temperature conditions of 25°C. In addition, even if the laminate of the present invention has a laminate-type structure in which another film is laminated on top of the ink layer, the anchor coat layer could be removed by the alkaline solution.

Claims

1. A laminate comprising a base material A, an anchor layer, and a vapor-deposited layer in that order, wherein the anchor layer is a film formed from a composition containing at least a urethane resin (A), the urethane resin (A) is a reaction product of a polyester polyol (a1) and a polyisocyanate (a2), the ester bond group concentration in the urethane resin (A) is 1 mmol / g or more, and the acid value of the urethane resin (A) is 8 to 45 mg KOH / g.

2. The laminate according to claim 1, wherein the polyester polyol (a1) is an aromatic polyester polyol containing aromatic dicarboxylic acid (a1-1) as a raw material monomer, and the concentration of aromatic rings derived from the raw material monomer of the aromatic dicarboxylic acid (a1-1) in the urethane resin (A) is 1 mmol / g or more.

3. The laminate according to claim 1 or 2, wherein the polyisocyanate (a2) is at least one selected from the group consisting of isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate.

4. The laminate according to claim 1 or 2, wherein the value obtained by dividing the mass of the raw material monomer of the polyisocyanate (a2) contained in 1 g of the urethane resin (A) by the NCO equivalent weight of the raw material monomer of the polyisocyanate (a2) is 1.0 to 6.0 mmol / g.

5. The laminate according to claim 1 or 2, wherein the weight-average molecular weight of the urethane resin (A) is 10,000 or more.

6. The laminate according to claim 1 or 2, wherein the glass transition temperature of the urethane resin (A) is 0 to 110°C.

7. The laminate according to claim 1 or 2, further comprising a protective layer on the vapor-deposited layer.

8. The laminate according to claim 1 or 2, wherein another substrate is bonded to the surface of the substrate A on which the vapor-deposited layer is arranged.

9. The laminate according to claim 8, wherein at least one layer selected from a printed layer, a barrier coat layer, an adhesive layer, a metal layer, and other vapor-deposited layers is placed between the vapor-deposited layer and another substrate.

10. Packaging material using the laminate described in claim 1.

11. A method for producing a recycled substrate A, obtained by treating the laminate according to claim 1 with an alkaline solution to detach the vapor-deposited layer together with the anchor layer from the substrate A.

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