Laminate

Abstract

To provide a laminate having improved environment consideration property, while having base material adhesion equivalent to a laminate having an adhesive layer including only a fossil fuel-derived resin.SOLUTION: A laminate includes a base material layer and an adhesive layer, wherein the adhesive layer contains an ethylene-unsaturated carboxylic acid-based copolymer composition (A), and a biomass degree of the whole composition (A) is more than 0 mass% and 100 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate. [Background technology]

[0002] Laminates using ethylene-unsaturated carboxylic acid copolymers, such as packaging materials, are laminated with various films to form multilayer laminates, which are used in a variety of applications including film and sheet applications. Patent documents 1 and 2 are cited as documents relating to laminates containing ethylene-unsaturated carboxylic acid copolymers used in such fields.

[0003] Patent Document 1 describes a laminate film for metallization, characterized in that it has, on at least one side of a base layer, a layer for vapor deposition made of a resin composition containing (I) 10 to 95% by weight of one or more ethylene copolymers selected from ethylene-(meth)acrylic acid ester copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-unsaturated glycidyl monomer copolymers, and ethylene-unsaturated dicarboxylic anhydride-(meth)acrylic acid ester terpolymers, each containing 50 to 95% by weight of an ethylene component, and (II) 5 to 90% by weight of a crystalline polyolefin having a melting point of 110° C. or higher. The document also describes that the laminate film for metallization has a layer for metallization (hereinafter referred to as the vapor deposition layer) made of a polyolefin composition that significantly improves the adhesion of the vapor-deposited metal film without impairing the inherent characteristics of polyolefin films, such as gloss.

[0004] Patent Document 2 describes a foamed wallpaper having a paper substrate, a resin layer, and a picture pattern layer, characterized in that (1) the resin layer contains at least one resin component selected from the group consisting of ethylene-vinyl acetate copolymer and ethylene-unsaturated carboxylic acid copolymer, and (2) the picture pattern layer is formed from an aqueous ink containing a urethane resin emulsion and is formed on the resin layer. It also describes that the foamed wallpaper can provide a foamed wallpaper with good adhesion of the picture pattern layer and good surface rubbing properties. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-39931 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-196590 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, resins containing ethylene-unsaturated carboxylic acid copolymers are generally derived from fossil fuels. However, petroleum, a fossil fuel, is in danger of becoming depleted, and the manufacturing process and disposal process of products emit large amounts of carbon dioxide, raising concerns about its impact on global warming.

[0007] The present invention has been made in consideration of the above circumstances, and provides a laminate having an adhesive layer that has improved environmental friendliness while having substrate adhesion equivalent to that of a laminate having an adhesive layer that contains only fossil fuel-derived resin as the resin component. [Means for solving the problem]

[0008] The present inventors have found that in a laminate comprising an adhesive layer containing an ethylene-unsaturated carboxylic acid copolymer composition (A) and a substrate layer, by using a resin component produced using a biomass-derived raw material for at least a part of the adhesive layer, it is possible to obtain a laminate with improved environmental friendliness while maintaining substrate adhesion equivalent to that of a laminate comprising an adhesive layer containing only fossil fuel-derived resins as the resin component.

[0009] The present invention provides the following laminate.

[0010] [1] A laminate comprising a base layer and an adhesive layer, the adhesive layer contains an ethylene-unsaturated carboxylic acid copolymer composition (A), A laminate in which the biomass content of the entire composition (A) is more than 0 mass % and 100 mass % or less. [2] The laminate according to [1], wherein the melt mass flow rate (MFR) of the composition (A) measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g is 0.1 g / 10 min or more and 300 g / 10 min or less. [3] The laminate according to [1] or [2], wherein the ethylene-unsaturated carboxylic acid copolymer in the composition (A) includes an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. [4] The laminate according to any one of [1] to [3], wherein the ethylene-unsaturated carboxylic acid copolymer in the composition (A) includes an ethylene-unsaturated carboxylic acid copolymer and an ethylene-unsaturated carboxylic acid ester copolymer. [5] The laminate according to any one of [1] to [4], wherein the content of structural units derived from unsaturated carboxylic acid in the composition (A) is 0.1% by mass or more and 20% by mass or less, when the total amount of the resin components in the composition (A) is 100% by mass. [6] The laminate according to any one of [1] to [5], wherein the content of structural units derived from an unsaturated carboxylic acid ester in the composition (A) is 0.1% by mass or more and 20% by mass or less, when the total amount of the resin components in the composition (A) is 100% by mass. [7] The laminate according to any one of [1] to [6], wherein the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer in the composition (A) includes at least one selected from the group consisting of acrylic acid and methacrylic acid. [8] The laminate according to any one of [1] to [7], comprising the base layer, the adhesive layer, and a sealant layer in this order. [9] The laminate according to [8], further comprising a barrier layer between the adhesive layer and the sealant layer. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a laminate that has improved environmental friendliness while having substrate adhesion equivalent to that of a laminate having an adhesive layer containing only a resin derived from fossil fuels as the resin component. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification, "A to B" indicating a range of values ​​means A or more and B or less unless otherwise specified. In this embodiment, the resin component includes the ethylene-unsaturated carboxylic acid copolymer in the ethylene-unsaturated carboxylic acid copolymer composition (A). On the other hand, the resin component does not include various additives that may be contained in the ethylene-unsaturated carboxylic acid copolymer composition (A). When the ethylene-unsaturated carboxylic acid copolymer composition (A) contains a resin other than the ethylene-unsaturated carboxylic acid copolymer, the total content of the ethylene-unsaturated carboxylic acid copolymer and the content of the other resin other than the ethylene-unsaturated carboxylic acid copolymer is the content of the resin component. In the present embodiment, the substrate adhesiveness refers to the interlayer adhesiveness between the substrate layer and the adhesive layer in the laminate of the present embodiment.

[0013] The laminate of this embodiment is a laminate comprising a base layer and an adhesive layer, wherein the adhesive layer contains an ethylene-unsaturated carboxylic acid copolymer composition (A), and the biomass content of the entire composition (A) is greater than 0 mass% and not more than 100 mass%.

[0014] According to this embodiment, it is possible to provide a laminate that has improved environmental friendliness while having substrate adhesion equivalent to that of a laminate having an adhesive layer that contains only fossil fuel-derived resin as the resin component.

[0015] 1.Adhesive layer The adhesive layer of this embodiment contains an ethylene-unsaturated carboxylic acid copolymer composition (A), which can improve the substrate adhesion of the laminate of this embodiment.

[0016] <Ethylene-unsaturated carboxylic acid copolymer composition (A)> The ethylene-unsaturated carboxylic acid copolymer in the ethylene-unsaturated carboxylic acid copolymer composition (A) (hereinafter also simply referred to as "composition (A)") is a copolymer containing ethylene-derived structural units and unsaturated carboxylic acid-derived structural units. The ethylene-unsaturated carboxylic acid copolymer may be in the form of a binary copolymer or a tertiary copolymer, and may also be in the form of a block copolymer, a random copolymer, or a graft copolymer. However, in consideration of suitability for extrusion lamination, it is preferable to use a binary random copolymer, a tertiary random copolymer, a graft copolymer of a binary random copolymer, or a graft copolymer of a tertiary random copolymer, and more preferably a binary random copolymer or a tertiary random copolymer.

[0017] The unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer in composition (A) includes, for example, at least one selected from the group consisting of acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, and monoethyl maleate. Among these, from the viewpoint of further improving the flexibility of the laminate of the present embodiment, it is preferable that the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer in composition (A) contains at least one selected from the group consisting of acrylic acid and methacrylic acid.

[0018] The ethylene-unsaturated carboxylic acid copolymer in composition (A) is a copolymer in which at least ethylene and an unsaturated carboxylic acid are copolymerized, and may also be a ternary or higher multi-component copolymer in which a third copolymerization component is further copolymerized. Examples of the third copolymerization component include unsaturated carboxylic acid esters (e.g., (meth)acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, isooctyl methacrylate, and 2-ethylhexyl methacrylate; dimethyl maleate; and diethyl maleate), vinyl esters (e.g., vinyl acetate and vinyl propionate), unsaturated hydrocarbons (e.g., propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, and 1-hexene), oxides such as vinyl sulfate and vinyl nitrate, halogen compounds (e.g., vinyl chloride and vinyl fluoride), vinyl group-containing primary and secondary amine compounds, carbon monoxide, and sulfur dioxide. Among these, the third copolymerization component is preferably an unsaturated carboxylic acid ester, more preferably a (meth)acrylic acid alkyl ester (the alkyl moiety preferably having 1 or more and 4 or less carbon atoms), from the viewpoint of further improving flexibility. These third copolymerization components may be used alone or in combination of two or more.

[0019] The ethylene-unsaturated carboxylic acid copolymer in the composition (A) may contain both a binary copolymer and a terpolymer, or may contain only one of them. The ethylene-unsaturated carboxylic acid copolymer in composition (A) preferably contains an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. The ethylene-unsaturated carboxylic acid copolymer preferably contains an ethylene-unsaturated carboxylic acid copolymer and an ethylene-unsaturated carboxylic acid ester copolymer. This further improves the adhesion between the adhesive layer and the substrate layer described below. Here, the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is preferably a terpolymer, and the ethylene-unsaturated carboxylic acid copolymer and the ethylene-unsaturated carboxylic acid ester copolymer are preferably binary copolymers.

[0020] The content of structural units derived from ethylene in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more from the viewpoint of further improving heat resistance, mechanical strength, etc., and is preferably 99.8% by mass or less, more preferably 99.5% by mass or less, even more preferably 99.3% by mass or less, and even more preferably 99.0% by mass or less from the viewpoint of further improving transparency. Furthermore, the content of structural units derived from ethylene in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 60% by mass or more and 99.8% by mass or less, more preferably 70% by mass or more and 99.5% by mass or less, even more preferably 80% by mass or more and 99.3% by mass or less, and even more preferably 90% by mass or more and 99.0% by mass or less.

[0021] The content of structural units derived from unsaturated carboxylic acids in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of further improving the adhesiveness of the laminate of this embodiment; and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of further improving the performance balance between processability and heat resistance. Furthermore, the content of structural units derived from unsaturated carboxylic acids in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 15% by mass or less, even more preferably 0.2% by mass or more and 10% by mass or less, even more preferably 0.3% by mass or more and 5% by mass or less, and even more preferably 0.3% by mass or more and 1% by mass or less.

[0022] The content of structural units derived from (meth)acrylic acid in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of further improving the adhesiveness of the laminate of the present embodiment, and is preferably 4% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of further improving the performance balance between processability and heat resistance. Furthermore, the content of structural units derived from (meth)acrylic acid in composition (A) is preferably 0.1% by mass or more and 4% by mass or less, more preferably 0.2% by mass or more and 3% by mass or less, and even more preferably 0.3% by mass or more and 2% by mass or less, when the total resin components in composition (A) are taken as 100% by mass.

[0023] When the entire resin component in composition (A) is taken as 100% by mass, the content of structural units derived from unsaturated carboxylic acid esters in composition (A) is, from the viewpoint of further improving adhesiveness, preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, and is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, even more preferably 0.7% by mass or more. Furthermore, the content of structural units derived from unsaturated carboxylic acid esters in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.3% by mass or more and 15% by mass or less, even more preferably 0.5% by mass or more and 10% by mass or less, even more preferably 0.5% by mass or more and 5% by mass or less, and even more preferably 0.7% by mass or more and 3% by mass or less.

[0024] The content of structural units derived from isobutyl (meth)acrylate in composition (A), when the entire resin component in composition (A) is taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of further improving the flexibility of the laminate of the present embodiment; and is preferably 15% by mass or less, more preferably 13% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 5% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of further improving the performance balance between processability and heat resistance. Furthermore, the content of structural units derived from isobutyl (meth)acrylate in composition (A) is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, and even more preferably 0.3% by mass or more and 5% by mass or less, when the total resin components in composition (A) are taken as 100% by mass.

[0025] Here, the content of structural units derived from ethylene, the content of structural units derived from unsaturated carboxylic acid, and the content of structural units derived from unsaturated carboxylic acid ester in composition (A) can be measured, for example, by Fourier transform infrared absorption spectroscopy (FT-IR).

[0026] Ethylene-unsaturated carboxylic acid copolymers can be obtained by radical polymerization of each polymer component under high temperature and pressure. Moreover, commercially available ethylene-unsaturated carboxylic acid copolymers may be used.

[0027] <Biomass ratio> From the viewpoint of improving environmental friendliness, the biomass degree of the entire ethylene-unsaturated carboxylic acid copolymer composition (A) is greater than 0% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, and even more preferably 60% by mass or more. There is no upper limit to the biomass degree of the ethylene-unsaturated carboxylic acid copolymer composition (A), but it may be 100% by mass or less, or may be 95% by mass or less, or may be 90% by mass or less. The biomass degree of the entire ethylene-unsaturated carboxylic acid copolymer composition (A) is greater than 0% by mass and not greater than 100% by mass, preferably from 0.01% by mass to 95% by mass, more preferably from 0.1% by mass to 95% by mass, even more preferably from 1% by mass to 95% by mass, even more preferably from 5% by mass to 95% by mass, even more preferably from 10% by mass to 90% by mass, even more preferably from 30% by mass to 90% by mass, and even more preferably from 50% by mass to 90% by mass. The biomass content of the ethylene-unsaturated carboxylic acid copolymer composition (A) can be calculated from the content (mass%) of biomass-derived structural units when the entire ethylene-unsaturated carboxylic acid copolymer composition (A) is taken as 100 mass%.

[0028] The ethylene-unsaturated carboxylic acid copolymer in the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment preferably contains a structural unit derived from a monomer obtained from biomass (hereinafter also referred to as a "biomass-derived monomer"), and more preferably contains a structural unit derived from ethylene obtained from biomass (hereinafter also referred to as a "biomass-derived ethylene").

[0029] <Biomass-derived ethylene> The method for producing biomass-derived ethylene is not limited, and known methods can be used. Examples of methods for producing biomass-derived ethylene are listed below.

[0030] "Biomass" refers to organic resources that are primarily derived from plants and animals, excluding fossil fuels. There are several methods for producing biomass-derived ethylene, including fermenting biomass feedstock with microorganisms to produce biomass-derived ethanol (bioethanol) and then dehydrating it, and extracting it from biomass naphtha, which is produced from vegetable oil waste and residual oil. Biomass raw materials include inedible and edible raw materials. Examples of inedible raw materials include cellulosic crops (pulp, kenaf, rice straw, etc.), waste paper, papermaking residues, wood, charcoal, compost, natural rubber, cotton, factory flue gas, waste gas, etc. Examples of edible raw materials include sugarcane, soybean pulp, corn, potatoes, wheat, rice, buckwheat, and soybeans. One or more types selected from the group consisting of these can be used as biomass raw materials. As vegetable oil waste and residual oil, various wastes, unused resources, resource crops, etc. can be used. Specifically, oils and fats such as rapeseed oil and soybean oil, essential oils such as eucalyptus oil, vegetable oil cake, etc. can be used. From the viewpoint of reducing the amount of carbon dioxide generated in the life cycle from raw materials to disposal of plastic products, it is preferable to use ethylene extracted from biomass naphtha.

[0031] Ethylene can be extracted from biomass naphtha by known methods such as heating, cracking, distillation, and purification, similar to extraction from naphtha derived from fossil fuels.

[0032] There are no particular limitations on the method for producing bioethanol, and bioethanol can be obtained by, for example, contacting edible biomass materials such as sugarcane or corn with ethanol-producing microorganisms, typically yeast, or products derived from their crushed material to ferment the sugars, followed by purification of the ethanol. Conventional methods such as distillation, membrane separation, and extraction can be used for ethanol purification. In addition, as a production method using non-edible raw materials as biomass raw materials, for example, synthesis gas (gas mainly composed of carbon monoxide and hydrogen) generated by burning non-edible raw materials that are waste resources such as used paper and paper manufacturing residues, or flue gas and waste gas emitted from factories, etc. can be used as a carbon source to obtain ethanol by fermenting them with microorganisms.

[0033] Biomass-derived ethylene can be obtained by dehydrating the ethanol obtained as described above. The dehydration reaction requires certain conditions, such as the type of catalyst, heating temperature, and pressure, but any conventional method can be used.

[0034] In the process of producing biomass ethylene obtained in this way, higher alcohol and higher alkene impurities may be produced during the ethanol fermentation and dehydration steps, and therefore, these by-products can be removed before or after the dehydration of ethanol.

[0035] <Other ingredients> The ethylene-unsaturated carboxylic acid copolymer composition (A) of this embodiment may contain various additives within the scope of the present invention, such as one or more additives selected from the group consisting of inorganic fillers such as silica and talc, antioxidants, weather stabilizers, wavelength converting agents, antistatic agents, antifogging agents, antiblocking agents, slip agents, and pigments. Furthermore, the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment may contain a resin other than the ethylene-unsaturated carboxylic acid copolymer within a range that does not impair the object of the present invention.

[0036] Resins other than ethylene-unsaturated carboxylic acid copolymers include polyolefins, polyamides, polyesters, and polyvinyl alcohols. Examples of polyolefins include those containing structural units derived from α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and 4-methyl-1-pentene. When the ethylene-unsaturated carboxylic acid copolymer composition (A) contains a resin other than the ethylene-unsaturated carboxylic acid copolymer, the resin other than the ethylene-unsaturated carboxylic acid copolymer may contain a biomass-derived monomer structural unit. Examples of the biomass-derived monomer include biomass-derived α-olefins. Biomass-derived α-olefins can also be produced using the above-mentioned biomass-derived ethylene as a raw material in the same manner as in the case of using fossil fuel-derived ethylene as a raw material.

[0037] The ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment can be prepared, for example, by simultaneously or successively mixing the ethylene-unsaturated carboxylic acid copolymer and other components, and the mixing order is not limited. As a preparation method, melt mixing using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, various kneaders, etc. is preferred.

[0038] The physical properties of the ethylene-unsaturated carboxylic acid copolymer composition (A) of this embodiment will be described below.

[0039] The melt mass flow rate (MFR) of the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment, measured in accordance with JIS K 7210:1999 at 190°C under a load of 2160 g, is preferably 0.1 g / 10 min or more, more preferably 1.0 g / 10 min or more, even more preferably 3.0 g / 10 min or more, even more preferably 5.0 g / 10 min or more, and even more preferably 7.0 g / 10 min or more, from the viewpoint of further improving moldability and processability, and is preferably 300 g / 10 min or less, more preferably 200 g / 10 min or less, even more preferably 100 g / 10 min or less, even more preferably 50 g / 10 min or less, even more preferably 30 g / 10 min or less, even more preferably 20 g / 10 min or less, and even more preferably 15 g / 10 min or less. The melt mass flow rate (MFR) of the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment, measured in accordance with JIS K 7210:1999 at 190°C under a load of 2160 g, is preferably 0.1 g / 10 min or more and 300 g / 10 min or less, more preferably 1.0 g / 10 min or more and 200 g / 10 min or less, even more preferably 3.0 g / 10 min or more and 100 g / 10 min or less, still more preferably 5.0 g / 10 min or more and 50 g / 10 min or less, still more preferably 7.0 g / 10 min or more and 30 g / 10 min or less, and still more preferably 7.0 g / 10 min or more and 15 g / 10 min or less.

[0040] The density of the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment, measured in accordance with JIS K 7112:1999, is preferably 900 kg / m from the viewpoint of further improving the balance of the performance of substrate adhesion and processability. 3 More preferably, 905 kg / m 3 More preferably, 910 kg / m 3 More preferably, 915 kg / m 3 From the viewpoint of further improving processability, it is preferably 950 kg / m 3 Less than or equal to 940 kg / m 3 or less, more preferably 930 kg / m 3 or less, more preferably 920 kg / m3 The following is the result. The density of the ethylene-unsaturated carboxylic acid copolymer composition (A) of the present embodiment, measured in accordance with JIS K 7112:1999, is preferably 900 kg / m 3 More than 950kg / m 3 Less than or equal to 905 kg / m 3 More than 940kg / m 3 or less, more preferably 910 kg / m 3 More than 930kg / m 3 or less, more preferably 915 kg / m 3 More than 920kg / m 3 The following is the result.

[0041] The thickness of the adhesive layer in this embodiment is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of improving adhesion, and is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less, from the viewpoint of improving flexibility of the laminate. The thickness of the adhesive layer is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less, and even more preferably 10 μm or more and 30 μm or less.

[0042] 2.Laminate The laminate of this embodiment includes the above-described adhesive layer and a base layer. Furthermore, the laminate of this embodiment has good suitability for extrusion lamination because the adhesive layer contains the ethylene-unsaturated carboxylic acid copolymer composition (A).

[0043] The laminate of the present embodiment may further include a sealant layer, or may include a base layer, an adhesive layer, and a sealant layer in this order. When the laminate of the present embodiment includes a sealant layer, a barrier layer may be further provided between the adhesive layer and the sealant layer. The barrier layer may be a single layer or a multi-layer consisting of two or more layers. The substrate layer may be a single layer or a multi-layer consisting of two or more layers. The laminate of the present embodiment may also have layers other than the adhesive layer, substrate layer, sealant layer, and barrier layer. For example, when the laminate has a substrate layer, an adhesive layer, and a sealant layer, another layer may be present between the substrate layer and the adhesive layer, or another layer may be present between the adhesive layer and the sealant layer. Examples of the other layers include an inorganic layer, an antistatic layer, a hard coat layer, an antireflection layer, an antifouling layer, an anchor coat layer, etc. The other layers may be used singly or in combination of two or more layers.

[0044] The overall thickness of the laminate of this embodiment is preferably 20 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, from the viewpoint of further improving the balance between the mechanical strength, flexibility, and heat sealability of the laminate, and is preferably 300 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less. The thickness of the entire laminate is preferably 20 μm or more and 300 μm or less, more preferably 50 μm or more and 250 μm or less, and even more preferably 100 μm or more and 200 μm or less.

[0045] <Base material layer> The substrate layer may include one or two materials selected from the group consisting of paper, various general-purpose films, barrier-coated films, metal-deposited films, metal foils, and the like. Examples of various general-purpose films include polyamide film, polypropylene film, polyester film (e.g., polyethylene terephthalate film), polyimide film, polyvinylidene chloride film, and ethylene-vinyl acetate copolymer film. Metal-deposited films are, for example, films in which metal is vapor-deposited on these general-purpose films, and examples include aluminum-deposited polyester (aluminum-deposited polyethylene terephthalate), aluminum-deposited polypropylene, and silica-deposited polyester. Examples of metal foils include copper foil and aluminum foil. These may be laminated together as needed.

[0046] The thickness of the substrate layer is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of further improving mechanical strength, and is preferably 150 μm or less, more preferably 120 μm or less, from the viewpoint of further improving flexibility. The thickness of the substrate layer is preferably 5 μm or more and 150 μm or less, and more preferably 10 μm or more and 120 μm or less.

[0047] <Sealant layer> The sealant layer provides heat sealing properties and can further enhance the protection of the contents. The sealant layer is made of polyolefin such as low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) to provide heat-sealing properties.

[0048] The thickness of the sealant layer is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, from the viewpoint of further improving the heat sealability, and is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less, from the viewpoint of further improving the flexibility of the laminate. The thickness of the sealant layer is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less, and even more preferably 15 μm or more and 30 μm or less.

[0049] <Barrier layer> The barrier layer is a layer that imparts gas barrier properties and water vapor barrier properties and also blocks odors from the outside air, so that when the laminate of this embodiment is used as a packaging container, for example, odors will not be transferred to the contents inside the container. The barrier layer may contain one or two types selected from the group consisting of various general-purpose films, barrier coated films, metallized films, metal foils, and the like that can be used for the above-mentioned base layer. The barrier layer may be subjected to physical treatment such as corona treatment, plasma treatment, or flame treatment on the surface that is bonded (or laminated) to the adhesive layer in order to increase the adhesive strength with the adhesive layer. The barrier layer may also be subjected to a known anchor coating treatment. Furthermore, when the adhesive layer is melt-laminated, ozone treatment or the like may also be performed.

[0050] The thickness of the barrier layer is preferably 5 μm or more from the viewpoint of further improving the barrier properties, and is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and even more preferably 20 μm or less from the viewpoint of improving the flexibility of the laminate. The thickness of the barrier layer is preferably 5 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less, and even more preferably 5 μm or more and 20 μm or less.

[0051] The method for producing the laminate of this embodiment can be applied to various known lamination methods, and preferably includes an extrusion step in which the adhesive layer is produced by melt extrusion lamination. The molding device and molding conditions in this extrusion step are not particularly limited, and conventionally known molding devices and molding conditions can be used. As the molding device, a T-die extruder or the like can be used. Furthermore, as the molding conditions, known molding conditions for melt extrusion lamination can be used. In the method for producing a laminate of this embodiment, the extrusion lamination temperature in the extrusion step is not particularly limited as it is appropriately set depending on the ethylene-unsaturated carboxylic acid copolymer composition (A) described above. However, from the viewpoint of further improving the adhesiveness of the laminate, the temperature is preferably 200°C or higher, more preferably 250°C or higher, and particularly preferably 280°C or higher. The upper limit of the extrusion lamination temperature in the extrusion step is not particularly limited, but is, for example, 350°C or lower.

[0052] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0053] The present embodiment will be described in detail below with reference to examples, etc. However, the present embodiment is not limited to the descriptions of these examples.

[0054] [material] The components used were as follows:

[0055] <Adhesive layer resin> <Ethylene-unsaturated carboxylic acid copolymer composition (A)> EMAA1: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer EMAA2: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer EMAA3: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer EMAA4: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer EMAA5: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer EMAA6: Ethylene-methacrylic acid-acrylic acid isobutyl ester copolymer

[0056] <Base material layer> PET film: Toray Industries, Inc., Lumirror S10, thickness 12 μm Aluminum-deposited PET film: Toray Advanced Film Co., Ltd., BR-PET1012, thickness 12 μm Aluminum foil, manufactured by Toyo Aluminum Co., Ltd., 1N30, thickness 7 μm

[0057] [Biomass content of ethylene-unsaturated carboxylic acid copolymer composition (A)] The biomass content (mass%) of the ethylene-unsaturated carboxylic acid copolymer composition (A) in each example was calculated from the content (mass%) of biomass-derived structural units when the entire ethylene-unsaturated carboxylic acid copolymer composition (A) was taken as 100 mass%.

[0058] [MFR of ethylene-unsaturated carboxylic acid copolymer composition (A)] The MFR (g / 10 min) of the ethylene-unsaturated carboxylic acid copolymer composition (A) in each example was measured at 190° C. and a load of 2160 g in accordance with JIS K7210:1999.

[0059] [Density of ethylene-unsaturated carboxylic acid copolymer composition (A)] The density (kg / m) of the ethylene-unsaturated carboxylic acid copolymer composition (A) in each example 3 ) was measured in accordance with JIS K 7112:1999.

[0060] (Examples and Comparative Examples) <Preparation of laminates used for adhesiveness evaluation> [PET film / adhesive layer / laminate film fabrication] Using an extrusion laminator equipped with a 65 mm diameter extruder (L / D = 28), an ethylene-unsaturated carboxylic acid copolymer composition (A) from each example listed in Table 1 was extruded onto the corona-treated surface of the PET film under the following processing conditions: die outlet resin temperature 320°C, air gap 110 mm, processing speed 80 m / min, and processing width 500 mm, to form an adhesive layer with a thickness of 15 μm. A laminate film (LDPE layer / PET film layer; the LDPE layer was Mirason 11P, manufactured by Dow Mitsui Polychemicals Co., Ltd., 15 μm thick) was then laminated on the opposite side of the adhesive layer to the PET film, with the LDPE layer facing the adhesive layer (layer structure: PET film layer (thickness 12 μm) / adhesive layer (thickness 15 μm) / LDPE layer (thickness 15 μm) / PET film layer (thickness 12 μm)).

[0061] [Production of aluminum-deposited PET film / adhesive layer / laminated film] Using an extrusion laminator equipped with a 65 mm diameter extruder (L / D = 28), an ethylene-unsaturated carboxylic acid copolymer composition (A) from each example listed in Table 1 was extruded onto the LDPE layer side of a laminated film (LDPE layer / PET film layer; the LDPE layer was Mirason 11P, manufactured by Mitsui Dow Polychemicals Co., Ltd., 15 μm thick) under the following processing conditions: die outlet resin temperature 320 °C, air gap 110 mm, processing speed 80 m / min, processing width 500 mm, to form an adhesive layer. An aluminum-vapor-deposited PET film was then laminated on the opposite side of the adhesive layer, with the vapor-deposited side facing the adhesive layer (layer structure: aluminum-vapor-deposited PET film layer (thickness 12 μm) / adhesive layer (thickness 15 μm) / LDPE layer (thickness 15 μm) / PET film layer (thickness 12 μm)).

[0062] [Aluminum foil laminated film / adhesive layer / laminate film production] Using an extrusion laminator with a 65 mmφ extruder (L / D=28), the ethylene-unsaturated carboxylic acid copolymer composition (A) of each example listed in Table 1 was extruded onto the LDPE layer side of a laminated film (LDPE layer / PET film layer, the LDPE layer was Mirason 11P, manufactured by Mitsui Dow Polychemicals Co., Ltd., thickness 15 μm) under processing conditions of a die outlet resin temperature of 320 ° C, an air gap of 110 mm, a processing speed of 80 m / min, and a processing width of 500 mm to form an adhesive layer, and a 15 μm thick adhesive layer was formed on the opposite side of the adhesive layer from the laminated film. The laminated film was made by laminating an aluminum foil (PET film layer / ethylene-methacrylic acid copolymer layer / aluminum foil; the ethylene-methacrylic acid copolymer layer was Nucrel AN4228C, 15 μm thick, manufactured by Mitsui Dow Polychemicals Co., Ltd.) so that the aluminum foil was positioned on the adhesive layer side (layer structure: PET film layer (thickness 12 μm) / ethylene-methacrylic acid copolymer layer (thickness 15 μm) / aluminum foil (thickness 7 μm) / adhesive layer (thickness 15 μm) / LDPE layer (thickness 15 μm) / PET film layer (thickness 12 μm)).

[0063] [Adhesion evaluation] Test pieces 100 mm long and 15 mm wide were cut out from the laminates (PET film / adhesive layer / laminated film, aluminum vapor-deposited PET film / adhesive layer / laminated film, and aluminum foil laminate film / adhesive layer / laminated film) prepared above, and the obtained test pieces were left to stand for 7 days in an environment of 23°C and 50% RH for aging. The PET film and adhesive layer, the aluminum-deposited PET film and adhesive layer, and the aluminum foil and adhesive layer in the aluminum foil laminate film were peeled from each aged test piece, and the adhesion of the adhesive layer to the PET film, aluminum-deposited film, and aluminum foil was evaluated. For each peel, the adhesive strength (N / 15 mm) was measured in the MD direction at a peel speed of 300 mm / min under T-type peel conditions using a tensile tester (Shimadzu Corporation, EZ-SX, 100 N) in accordance with JIS K 7161-1:2014.

[0064] The adhesion to PET film, aluminum vapor deposition film, and aluminum foil was evaluated according to the following criteria. The results are shown in Table 1. (standard) Adhesion to PET A (Good): Adhesive strength is 2.5N / 15mm or more B (poor): Adhesive strength less than 2.5N / 15mm Adhesion to aluminum vapor deposition film A (Good): Adhesive strength is 0.8N / 15mm or more B (poor): Adhesive strength less than 0.8N / 15mm Adhesion to aluminum foil A (Good): Adhesive strength is 1.3N / 15mm or more B (poor): Adhesive strength less than 1.3N / 15mm

[0065] [Extrusion lamination processing suitability evaluation] An extrusion laminator having a 65 mmφ extruder (L / D=28) was used to extrude the ethylene-unsaturated carboxylic acid copolymer composition (A) of each example shown in Table 1 at a die outlet resin temperature of 320°C, an air gap of 110 mm, a processing speed of 80 m / min, and a die opening width of 500 mm. The difference between the resin coating width on the substrate (kraft paper, thickness 50 gsm) and the die opening width was taken as the neck-in value (mm). Under the above neck-in value measurement conditions, the take-up speed value at which the molten film was cut when the take-up speed was increased was taken as the draw-down value (mm / min). The neck-in value and draw-down value of the extrusion lamination suitability were evaluated according to the following criteria. The results are shown in Table 1. (standard) Neck-in value A (good): Less than 60 mm B (defective): 60mm or more Drawdown value A (good): 200mm / min or more B (bad): Less than 200 mm / min

[0066] [Table 1]

[0067] As is clear from Table 1, although the laminates of Examples 1 to 4 contained biomass-derived structural units as part of the composition (A) constituting the adhesive layer, the PET adhesion, aluminum vapor deposition film adhesion, and aluminum foil adhesion were all equivalent to those of the laminates of Comparative Examples 1 and 2, which used only fossil fuel-derived resins in the adhesive layer.

Claims

1. A laminate comprising a base layer and an adhesive layer, the adhesive layer contains an ethylene-unsaturated carboxylic acid copolymer composition (A), A laminate in which the biomass content of the entire composition (A) is more than 0 mass% and 100 mass% or less.

2. 2. The laminate according to claim 1, wherein the composition (A) has a melt mass flow rate (MFR) of 0.1 g / 10 min or more and 300 g / 10 min or less, as measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g.

3. The laminate according to claim 1 or 2, wherein the ethylene-unsaturated carboxylic acid copolymer in the composition (A) includes an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer.

4. The laminate according to any one of claims 1 to 3, wherein the ethylene-unsaturated carboxylic acid copolymer in the composition (A) comprises an ethylene-unsaturated carboxylic acid copolymer and an ethylene-unsaturated carboxylic acid ester copolymer.

5. 5. The laminate according to claim 1, wherein the content of structural units derived from unsaturated carboxylic acid in the composition (A) is 0.1% by mass or more and 20% by mass or less, when the entire resin component in the composition (A) is taken as 100% by mass.

6. 6. The laminate according to claim 1, wherein the content of structural units derived from an unsaturated carboxylic acid ester in the composition (A) is 0.1% by mass or more and 20% by mass or less, when the entire resin component in the composition (A) is taken as 100% by mass.

7. The laminate according to any one of claims 1 to 6, wherein the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer in the composition (A) comprises at least one selected from the group consisting of acrylic acid and methacrylic acid.

8. The laminate according to any one of claims 1 to 7, comprising the base material layer, the adhesive layer, and a sealant layer in this order.

9. The laminate of claim 8 further comprising a barrier layer between the adhesive layer and the sealant layer.

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