Laminated body

Abstract

Provided are a laminate that can well maintain the interlayer adhesion, appearance, and gas barrier property after bending and has excellent reusability, and an article having the laminate. The laminate includes: a gas barrier layer (A) containing an ethylene-vinyl alcohol copolymer (a) and a polyurethane layer (B) containing a thermoplastic polyurethane (b). The laminate has a structure in which at least one set of the gas barrier layer (A) and the polyurethane layer (B) are directly laminated. The total number of the layers of the gas barrier layer (A) and the polyurethane layer (B) is 9 or more and 300 or less. The gas barrier layer (A) contains a higher fatty acid metal salt (c) having 10 or more carbon atoms and 10 ppm or more and 300 ppm or less in terms of metal atom conversion.

Description

Technical Field

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

[0002] Films obtained using resins having gas barrier properties such as ethylene-vinyl alcohol copolymers are widely used for various purposes such as food and medical packaging materials. Recently, various laminates having a plurality of resin layers having a single layer thickness of the micrometer order or the submicrometer order have been proposed for the purpose of improving various properties such as gas barrier properties.

[0003] As an existing laminate having a plurality of resin layers stacked with ethylene-vinyl alcohol copolymers, for example, Patent Document 1 describes a multilayer structure having a total of 8 or more layers, wherein the layers are formed from a resin composition containing a gas barrier resin such as ethylene-vinyl alcohol copolymer and a layer formed from a thermoplastic resin such as thermoplastic polyurethane, and describes that by making any of the adjacent resin layers contain a metal salt, a multilayer structure having excellent interlayer adhesion can be provided.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: International Publication No. 2011 / 068105. Summary of the invention

[0007] Problems to be solved by the invention

[0008] It is known that the laminate having more than 8 layers as described in Patent Document 1 has excellent gas barrier properties after bending, but when melt-molding is performed in order to reuse defective products, scraps, etc. of the laminate, the hue of the resin deteriorates or the degraded resin adheres to the screw in the melt-molding machine, etc., and there is room for improvement in reusability.

[0009] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a laminate having excellent recyclability while maintaining good interlayer adhesion, appearance, and gas barrier properties after bending.

[0010] Methods used to solve problems

[0011] According to the present invention, the above object is achieved by providing the following technical solutions.

[0012] [1] A laminate comprising: a gas barrier layer (A) comprising an ethylene-vinyl alcohol copolymer (a) and a polyurethane layer (B) comprising a thermoplastic polyurethane (b), the laminate comprising a structure in which at least one set of the gas barrier layer (A) and the polyurethane layer (B) are directly laminated, the total number of layers of the gas barrier layer (A) and the number of layers of the polyurethane layer (B) is 9 or more and 300 or less, and the gas barrier layer (A) contains a higher fatty acid metal salt (c) having 10 or more carbon atoms in an amount of 10 ppm or more and 300 ppm or less in terms of metal atoms;

[0013] [2] The laminate according to [1], wherein the metal atom constituting the higher fatty acid metal salt (c) includes at least one selected from magnesium and cobalt;

[0014] [3] The laminate according to [2], wherein the higher fatty acid metal salt (c) comprises at least one selected from magnesium stearate and cobalt stearate;

[0015] [4] The laminate according to any one of [1] to [3], wherein the ethylene unit content of the ethylene-vinyl alcohol copolymer (a) is 20 mol% to 60 mol%;

[0016] [5] The laminate according to any one of [1] to [4], wherein the gas barrier layer (A) and the polyurethane layer (B) are alternately laminated;

[0017] [6] The laminate according to [5], wherein the polyurethane layer (B) comprises a polyurethane layer (B1) and a polyurethane layer (B2), wherein the polyurethane layer (B1) has the gas barrier layer (A) directly laminated on both surfaces, and the polyurethane layer (B2) has the gas barrier layer (A) directly laminated on only one surface;

[0018] [7] The laminate according to [6], comprising a protective layer (D) directly laminated on the polyurethane layer (B2), wherein the protective layer (D) comprises a thermoplastic polyurethane (x);

[0019] [8] The laminate according to [7], wherein the protective layer (D) comprises an ethylene-vinyl alcohol copolymer (y);

[0020] [9] The laminate according to [7] or [8], wherein the average thickness of each protective layer (D) is 300 μm or more and 800 μm or less;

[0021]

[10] The laminate according to any one of [1] to [9], wherein the outermost layer is a polyurethane layer (B);

[0022]

[11] The laminate according to any one of [1] to

[10] , wherein the average thickness of each gas barrier layer (A) is 0.1 μm to 10 μm.

[0023]

[12] The laminate according to any one of [1] to

[11] , wherein the average thickness of each polyurethane layer (B) is 0.1 μm to 30 μm.

[0024]

[13] The laminate according to any one of [1] to

[12] , wherein the ratio of the average thickness of each gas barrier layer (A) to the average thickness of each polyurethane layer (B) (gas barrier layer (A) / polyurethane layer (B)) is 0.1 or more and 1 or less.

[0025] Effects of the Invention

[0026] According to the present invention, it is possible to provide a laminate having excellent recyclability while maintaining good interlayer adhesion, appearance, and gas barrier properties after bending, and a product including the laminate. DETAILED DESCRIPTION

[0027] 〈Laminated body〉

[0028] The laminate of the present invention comprises a gas barrier layer (A) (hereinafter sometimes abbreviated as “A layer”) containing an ethylene-vinyl alcohol copolymer (a) (hereinafter sometimes abbreviated as “EVOH (a)”) and a polyurethane layer (B) (hereinafter sometimes abbreviated as “B layer”) containing a thermoplastic polyurethane (b) (hereinafter sometimes abbreviated as “TPU (b)”), wherein the laminate comprises a structure in which at least one set of A layer and B layer are directly laminated, the total number of layers of the gas barrier layer (A) and the number of layers of the polyurethane layer (B) is 9 or more and 300 or less, and the A layer contains a higher fatty acid metal salt (c) having 10 or more carbon atoms in an amount of 10 ppm or more and 300 ppm or less in terms of metal atoms (hereinafter sometimes abbreviated as “higher fatty acid metal salt (c)”). By having a laminated structure including at least one group of A layer and B layer directly laminated and containing a specific amount of a higher fatty acid metal salt (c), it is possible to maintain the high gas barrier properties and bending resistance obtained by the laminated structure, and in the case of melt molding for the purpose of recycling scraps, etc., it is possible to suppress the deterioration of the resin hue and the adhesion of the degraded resin to the screw in the melt molding machine. It should be noted that in the specification of this application, "gas barrier properties" can be evaluated based on the measured value of oxygen permeability, specifically, it can be evaluated using the method described in the examples. In addition, in this specification, "ppm" refers to the content rate based on mass.

[0029] The laminate of the present invention may consist of only the A layer and the B layer, or may have other resin layers in addition to the A layer and the B layer. In addition, from the viewpoint of suppressing the reduction of mechanical properties during melt molding for the purpose of recycling scraps, etc., it is preferably composed of only the A layer and the B layer, and when other resin layers are provided, the other resin layers are preferably the outermost layers.

[0030] The laminate of the present invention comprises a structure formed by directly stacking at least one group of A layers and B layers, preferably a structure formed by directly stacking at least four groups of A layers and B layers, and preferably all A layers and B layers constituting the laminate are directly stacked with any A layer or B layer. By having the above-mentioned directly stacked structure, there is a tendency that the reduction of gas barrier properties during bending is suppressed. In addition, when melt molding is performed for the purpose of recycling scraps, the higher fatty acid metal salt (c) contained in the A layer (EVOH) is effectively transferred to the B layer (polyurethane). From the viewpoint of achieving better recyclability, it is preferred that the A layer and the B layer are alternately stacked.

[0031] The laminate of the present invention preferably has a symmetrical structure (eg, B layer / A layer / B layer / A layer / B layer / A layer / B layer / A layer / B layer / A layer / B layer) from the viewpoint of enabling efficient coextrusion.

[0032] In the case where the A layer and the B layer are alternately laminated, from the viewpoint of further suppressing the reduction in gas barrier properties when the layer is bent, the B layer preferably includes a polyurethane layer (B1) (hereinafter sometimes abbreviated as "B1 layer") and a polyurethane layer (B2) (hereinafter sometimes abbreviated as "B2 layer"), wherein the polyurethane layer (B1) is directly laminated with the A layer on both sides, and the polyurethane layer (B2) is directly laminated with the A layer only on one side. That is, it is preferred that at least one outermost layer in the alternately laminated portion of the A layer and the B layer is the B layer. It is more preferred that the B layer as at least one outermost layer in the alternately laminated portion is the B2 layer, and the other B layer is the B1 layer. Furthermore, it is more preferred that the B layer includes two B2 layers. That is, it is more preferred that the two outermost layers in the alternately laminated portion of the A layer and the B layer are the B layer.

[0033] In the case of having a B2 layer, from the viewpoint of further suppressing the reduction in gas barrier properties when the layer is bent, the laminate of the present invention preferably has a protective layer (D) (hereinafter sometimes abbreviated as "D layer") directly laminated on the B2 layer. The protective layer (D) is a layer containing a thermoplastic polyurethane (x) (hereinafter sometimes abbreviated as "TPU (x)"), preferably containing an ethylene-vinyl alcohol copolymer (y) (hereinafter sometimes abbreviated as "EVOH (y)"). As a layer structure of a laminate having a D layer, D layer / B2 layer / A layer / B1 layer / A layer / B1 layer / A layer / B1 layer / A layer / B2 layer / D layer can be exemplified. The D layer is preferably the outermost layer. The D layer can be provided only on one side, preferably on both sides. The laminate of the present invention can be a structure consisting only of an A layer and a B layer, a structure consisting only of an A layer, a B layer and a D layer, or a structure further having other resin layers.

[0034] The number of layers of the A layer constituting the laminate of the present invention is preferably 4 or more layers, more preferably 6 or more layers, and further preferably 8 or more layers. If the number of layers of the A layer is 4 or more layers, the reduction in gas barrier properties when the laminate is bent is further suppressed, so it is preferred. On the other hand, the number of layers of the A layer may be 150 or less layers.

[0035] The number of layers of the B layer constituting the laminate of the present invention is preferably 4 or more layers, more preferably 6 or more layers, and further preferably 7 or more layers. If the number of layers of the B layer is 4 or more layers, the reduction in gas barrier properties during bending is further suppressed, so it is preferred. On the other hand, the number of layers of the B layer may be 150 or less layers.

[0036] The total number of layers of the A layer and the number of layers of the B layer constituting the laminate of the present invention is 9 layers or more, preferably 11 layers or more, more preferably 15 layers or more, further preferably 25 layers or more, and particularly preferably 30 layers or more. On the other hand, the total number of layers of the A layer and the number of layers of the B layer is 300 layers or less, preferably 200 layers or less, and more preferably 100 layers or less. In addition, the total number of layers of the laminate is also preferably within the above range. By making the laminate into a multilayer structure in this way, even if defects such as pinholes and cracks are generated in a certain A layer due to bending, the gas barrier properties can be maintained by using other A layers, and as a result, the gas barrier properties, durability and other properties of the laminate as a whole can be improved.

[0037] In addition, when melt-kneading is performed for reuse, the problem of deterioration of the hue of the resin or adhesion of the degraded resin to the screw in the melt-molding machine is a unique problem that occurs significantly in the case of existing laminates with a large number of layers. It can be considered that: when a laminate with a large number of layers is melt-kneaded, EVOH (a) and TPU (b) are finely dispersed and mixed, so it is easy to excessively undergo ester exchange reactions, etc., which promotes the deterioration of the hue of the resin. A laminate with a total of 9 layers and B layers can enjoy the following advantages: by making the A layer contain a specified amount of a higher fatty acid metal salt (c), etc., even such a multi-layer laminate has excellent recyclability. Furthermore, in the present invention, by making the A layer contain a specified amount of a higher fatty acid metal salt (c), there is a tendency to improve recyclability by making the laminate into a multi-layer structure, which is contrary to the past. The reason for this is not clear, but it is presumed that during melt-kneading, the higher fatty acid metal salt (c) is easily dispersed throughout the entire melt-kneaded product, and the effect of the higher fatty acid metal salt (c) is easily exerted as a whole.

[0038] The average thickness of each layer of layer A is preferably 0.1 μm or more, more preferably 0.2 μm or more, and further preferably 0.3 μm or more. On the other hand, the average thickness of each layer of layer A is preferably 10 μm or less, more preferably 5 μm or less, further preferably 3 μm or less, and particularly preferably 2 μm or less. If the average thickness of each layer of layer A is 0.1 μm or more, the following tendency is shown: it is easier to form with uniform thickness, and the gas barrier properties and its durability are further improved. On the contrary, if the average thickness of each layer of layer A is 10 μm or less, the softness is improved, and as a result, the durability is also improved. In addition, when the average thickness of each layer of layer A is 10 μm or less, there is a tendency to further improve the recyclability. It can be inferred that when melt-kneading is performed in order to reuse scraps, the higher fatty acid metal salt (c) contained in layer A can be evenly dispersed in the entire melt-kneaded material.

[0039] The average thickness of each layer of the B layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 1 μm or more, and particularly preferably 3 μm or more. On the other hand, the average thickness of each layer of the B layer is preferably 30 μm or less, more preferably 15 μm or less, further preferably 10 μm or less, and particularly preferably 8 μm or less. If the average thickness of each layer of the B layer is 0.1 μm or more, the following tendency is shown: it is relatively easy to form with uniform thickness, and the durability is further improved. In addition, it is easy to show sufficient softness. On the contrary, if the average thickness of each layer of the B layer is 30 μm or less, there is a tendency to improve interlayer adhesion and gas barrier properties. In addition, when the average thickness of each layer of the B layer is 30 μm or less, there is a tendency to further improve recyclability. It can be inferred that when melt-kneading is performed for the purpose of recycling scraps, the higher fatty acid metal salt (c) contained in the A layer can be effectively transferred to the entire polyurethane of the B layer.

[0040] The average thickness of each layer of the B1 layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 1 μm or more, and particularly preferably 3 μm or more. On the other hand, the average thickness of each layer of the B1 layer is preferably 20 μm or less, more preferably 15 μm or less, further preferably 10 μm or less, and particularly preferably 8 μm or less. If the average thickness of each layer of the B1 layer is 0.1 μm or more, the following tendency is shown: it is relatively easy to form with uniform thickness, and the durability is further improved. In addition, it is easy to show sufficient softness. On the contrary, if the average thickness of each layer of the B1 layer is 20 μm or less, there is a tendency to improve interlayer adhesion and gas barrier properties. In addition, when the average thickness of each layer of the B1 layer is 20 μm or less, there is a tendency to further improve recyclability. It can be inferred that when melt-kneading is performed for the purpose of recycling scraps, the higher fatty acid metal salt (c) contained in the A layer can be effectively transferred to the entire polyurethane of the B1 layer.

[0041] The average thickness of each layer of the B2 layer is preferably 1 μm or more, more preferably 3 μm or more, and further preferably 10 μm or more. On the other hand, the average thickness of each layer of the B2 layer is preferably 30 μm or less, more preferably 25 μm or less, and further preferably 20 μm or less. If the average thickness of each layer of the B2 layer is 1 μm or more, the durability tends to be further improved. In addition, it is easy to show sufficient softness. On the contrary, if the average thickness of each layer of the B2 layer is 30 μm or less, the interlayer adhesion and gas barrier properties tend to be improved. In addition, when the average thickness of each layer of the B2 layer is 30 μm or less, there is a tendency to further improve the recyclability. It can be inferred that when melt-kneading is performed in order to reuse scraps, the higher fatty acid metal salt (c) contained in the A layer can be effectively transferred to the polyurethane as a whole of the B2 layer.

[0042] When the laminate of the present invention includes a D layer, the average thickness of each layer of the D layer is preferably 300 μm or more, more preferably 350 μm or more, and further preferably 400 μm or more. On the other hand, the average thickness of the D layer is preferably 800 μm or less, more preferably 750 μm or less, and further preferably 700 μm or less. If the average thickness of the D layer is 300 μm or more, the durability tends to be further improved. In addition, it is easy to show sufficient flexibility. On the contrary, if the average thickness of the D layer is 800 μm or less, the gas barrier property after bending tends to be improved.

[0043] The total thickness of all layers of layer A and all layers of layer B can be, for example, 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and further preferably 30 μm or more. On the other hand, the total thickness of all layers of layer A and all layers of layer B is preferably 500 μm or less, more preferably 300 μm or less, and further preferably 100 μm or less. When the total thickness of all layers of layer A and all layers of layer B is above 10 μm, there is a tendency to further improve bending resistance, durability, gas barrier properties, etc. On the contrary, when the total thickness is less than 500 μm, flexibility, formability, etc. are improved, and the reduction in bending resistance and the increase in manufacturing costs can be suppressed. Here, the total thickness of all layers refers to the sum of the average thickness of each layer. In a laminated body in which only layer A and layer B are present, the thickness of the entire laminated body in which only layer A and layer B are present can be set to the total thickness. The average thickness of each layer of each layer is set to the average value of the cross-sectional thickness at any 10 points.

[0044] The ratio of the average thickness of each layer of the A layer to the average thickness of each layer of the B layer (gas barrier layer (A) / polyurethane layer (B)) is preferably 0.1 or more, more preferably 0.15 or more, and more preferably 0.2 or more. In addition, the above ratio is preferably 1 or less, preferably 0.8 or less, and more preferably 0.6 or less. If the ratio (A / B) of the average thickness of each layer of the A layer to the average thickness of each layer of the B layer is 0.1 or more, the cracks in the A layer caused by the stress during bending are reduced, and therefore, there is a tendency that the reduction in gas barrier properties is suppressed. In addition, if the ratio (A / B) is 1 or less, the stress during bending is relieved by the B layer, and therefore, there is a tendency that the cracks in the A layer are reduced and the reduction in gas barrier properties is suppressed. In addition, when the ratio of the average thickness of each layer of the A layer to the average thickness of each layer of the B layer is within the above range, the content of the higher fatty acid metal salt (c) reaches a suitable amount for the entire laminate, and there is a tendency to further improve recyclability.

[0045] The overall average thickness of the laminate of the present invention is not particularly limited and can be appropriately set according to the purpose, function, etc. For example, by setting it to a thinner thickness, it is possible to achieve lightweight, etc., and by setting it to a thicker thickness, it is possible to further improve the gas barrier properties, etc. The lower limit of the overall average thickness of the laminate of the present invention can be, for example, 5 μm, 10 μm, 15 μm, 30 μm, 100 μm or 300 μm. On the other hand, the upper limit can be 3 mm, 1 mm, 500 μm, 300 μm or 100 μm.

[0046] The interlayer adhesion between layer A and layer B of the laminate of the present invention is preferably 300g / 15mm or more, more preferably 500g / 15mm or more, and further preferably 700g / 15mm or more. In addition, the interlayer adhesion of the laminate of the present invention can be 1500g / 15mm or less. If the interlayer adhesion is 300g / 15mm or more, there is a tendency that interlayer peeling during bending is suppressed. As means for improving the interlayer adhesion of the laminate of the present invention, methods such as increasing the amount of the higher fatty acid metal salt (c) added in an appropriate range, directly laminating the A layer and the B layer, and alternately laminating the A layer and the B layer can be cited. The interlayer adhesion of the laminate of the present invention can be measured using the method described in the embodiments.

[0047] The oxygen permeability (OTR) of the laminate of the present invention measured at 20°C and 65%RH is preferably 20 mL / (m 2 ・day・atm)or less, more preferably 15mL / (m 2 ・day・atm)or less, more preferably 10mL / (m 2 ・day・atm)or less. In addition, OTR can be 0.2mL / (m 2 ・day・atm)or more. If the oxygen permeability of the laminate of the present invention is within the above range, it can be suitably used as a material requiring durability. In addition, the OTR of the laminate of the present invention after bending described in the examples is preferably 60 mL / (m 2 ・day・atm)or less, more preferably 20mL / (m 2 ・day・atm)below. In addition, the OTR after bending can be 0.3mL / (m 2 ・day・atm)or more. If the OTR after bending of the laminated body of the present invention is within the above range, it can be suitably used as a material requiring stretchability. The OTR of the present invention and the OTR after bending can be measured by the method described in the Examples.

[0048] The laminate of the present invention can suppress coloration even when it is melt-kneaded again, although it is a multi-layer laminate. The reason for this is not clear, but it is speculated that: 1) the higher fatty acid is not easy to volatilize, so the thermal stability brought by the higher fatty acid metal salt (c) is maintained; 2) the higher fatty acid metal salt (c) is easily dispersed in the entire resin during melt-kneading, so the effect of suppressing coloration is improved.

[0049] 〈A layer〉

[0050] The A layer is a layer containing EVOH (a). When the A layer contains EVOH (a), a laminate having excellent gas barrier properties can be obtained.

[0051] The content of EVOH (a) in layer A is preferably 60% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more. The resin constituting layer A may be 100% by mass of EVOH (a).

[0052] 〈EVOH (a)〉

[0053] EVOH (a) is a polymer having ethylene units and vinyl alcohol units as main structural units. It should be noted that EVOH (a) may contain one or more other structural units in addition to ethylene units and vinyl alcohol units. EVOH (a) is generally obtained by polymerizing ethylene and vinyl ester and saponifying the resulting ethylene-vinyl ester copolymer.

[0054] The ethylene unit content of EVOH (a) (i.e., the ratio of the number of ethylene units in EVOH (a) to the total number of monomer units) is preferably 20 mol% or more, more preferably 25 mol% or more, further preferably 30 mol% or more, and particularly preferably 35 mol% or more. On the other hand, the ethylene unit content of EVOH (a) is preferably 60 mol% or less, more preferably 55 mol% or less. If the ethylene unit content of EVOH (a) is 20 mol% or more, the gas barrier properties of the obtained laminate under high humidity are further improved, and the melt formability is also improved. Conversely, if the ethylene unit content of EVOH (a) is 60 mol% or less, the gas barrier properties of the obtained laminate are further improved.

[0055] The saponification degree of EVOH (a) (i.e., the ratio of the number of vinyl alcohol units in EVOH (a) to the total number of vinyl alcohol units and vinyl ester units) is preferably 80 mol% or more, more preferably 95 mol% or more, and particularly preferably 99 mol% or more. On the other hand, the saponification degree of EVOH (a) is preferably 99.99 mol% or less. If the saponification degree of EVOH (a) is 80 mol% or more, the melt formability tends to be improved, and sometimes the gas barrier properties of the laminate are further improved, and the coloring resistance and moisture resistance are also improved. On the other hand, when the saponification degree of EVOH (a) is 99.99 mol% or less, the increase in the manufacturing cost of EVOH (a) can be suppressed, and sufficient gas barrier properties can be exerted. The EVOH (a) can also be used alone, and an embodiment in which it is blended with EVOH (a) having a saponification degree exceeding 99 mol% is also suitable.

[0056] EVOH (a) preferably has at least one of a structural unit (I) represented by the following formula (I), a structural unit (II) represented by the following formula (II), and a structural unit (III) represented by the following formula (III). By making EVOH (a) have such structural units, the bending resistance of the obtained laminate can be further improved.

[0057] [Chemistry 1]

[0058]

[0059] In the above formula (I), R 1 , R 2 and R 3 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a hydroxyl group. 1 , R 2 and R 3 In addition, a part or all of the hydrogen atoms in the aliphatic hydrocarbon group having 1 to 10 carbon atoms, the alicyclic hydrocarbon group having 3 to 10 carbon atoms, and the aromatic hydrocarbon group having 6 to 10 carbon atoms may be substituted with a hydroxyl group, a carboxyl group, or a halogen atom.

[0060] In the above formula (II), R 4 , R 5 , R 6 and R 7 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a hydroxyl group. 4 With R 5 or R 6 With R 7 In addition, some or all of the hydrogen atoms in the aliphatic hydrocarbon group having 1 to 10 carbon atoms, the alicyclic hydrocarbon group having 3 to 10 carbon atoms, and the aromatic hydrocarbon group having 6 to 10 carbon atoms may be substituted with a hydroxyl group, an alkoxy group, a carboxyl group, or a halogen atom.

[0061] In the above formula (III), R 8 , R 9 , R 10 and R 11 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a hydroxyl group. In addition, a part or all of the hydrogen atoms in the aliphatic hydrocarbon group having 1 to 10 carbon atoms, the alicyclic hydrocarbon group having 3 to 10 carbon atoms, and the aromatic hydrocarbon group having 6 to 10 carbon atoms may be substituted with a hydroxyl group, an alkoxy group, a carboxyl group, or a halogen atom.12 and R 13 Each independently represents a hydrogen atom, a formyl group or an alkanoyl group having 2 to 10 carbon atoms.

[0062] The content of the structural units (I), (II) or (III) relative to the total structural units is preferably 0.5 mol% or more, more preferably 1 mol% or more, and further preferably 1.5 mol% or more. On the other hand, the content of the structural units (I), (II) or (III) is preferably 30 mol% or less, more preferably 15 mol% or less, and further preferably 10 mol% or less. If EVOH (a) has the structural units represented by (I), (II) or (III) in the above-mentioned range, the flexibility and processing characteristics of the material forming the A layer are improved, and the stretchability and thermoformability of the obtained laminate can be improved.

[0063] In the structural units (I), (II) or (III), examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include alkyl and alkenyl groups, examples of the alicyclic hydrocarbon group having 3 to 10 carbon atoms include cycloalkyl and cycloalkenyl groups, and examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include phenyl groups.

[0064] In the above structural unit (I), the above R 1 , R 2 and R 3 Each of them is independently preferably a hydrogen atom, a methyl group, an ethyl group, a hydroxyl group, a hydroxymethyl group, and a hydroxyethyl group, and among these, each of them is independently more preferably a hydrogen atom, a methyl group, a hydroxyl group, and a hydroxymethyl group. 1 , R 2 and R 3 , thereby further improving the stretchability and thermoformability of the laminate.

[0065] The method for making EVOH (a) contain the above-mentioned structural unit (I) is not particularly limited, and examples thereof include a method of copolymerizing a monomer derived from the structural unit (I) in the polymerization of the above-mentioned ethylene and vinyl ester. Examples of the monomer derived from the structural unit (I) include olefins such as propylene, butene, pentene, and hexene; 3-hydroxy-1-propylene, 3-acyloxy-1-propylene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-hydroxy-1-butene, 4-acyloxy-3-hydroxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diacyloxy-2-methyl-1-butene, 4-hydroxy-1-pentene, 5-hydroxy Olefins having a hydroxyl group or an ester group such as 4-hydroxy-1-pentene, 4,5-dihydroxy-1-pentene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-hydroxy-3-methyl-1-pentene, 5-hydroxy-3-methyl-1-pentene, 4,5-dihydroxy-3-methyl-1-pentene, 5,6-dihydroxy-1-hexene, 4-hydroxy-1-hexene, 5-hydroxy-1-hexene, 6-hydroxy-1-hexene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6-acyloxy-1-hexene and 5,6-diacyloxy-1-hexene. Among them, propylene, 3-acetoxy-1-propylene, 3-acetoxy-1-butene, 4-acetoxy-1-butene and 3,4-diacetoxy-1-butene are preferred from the viewpoint of copolymerization reactivity and gas barrier properties of the obtained laminate. In the case of an olefin having an ester group, the structural unit (I) is derived during the saponification reaction.

[0066] In the above structural unit (II), preferably R 4 and R 5 are all hydrogen atoms. In particular, more preferred are: R 4 and R 5 are all hydrogen atoms, and the above R 6 and R 7 One of them is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and the other is a hydrogen atom. The aliphatic hydrocarbon group is preferably an alkyl group or an alkenyl group. From the viewpoint of attaching particular importance to the gas barrier properties of the obtained laminate, it is particularly preferred that: R 6 and R 7 One of them is a methyl group or an ethyl group, and the other is a hydrogen atom. In addition, it is particularly preferred that: 6 and R 7 One of them is (CH 2 ) h OH (wherein h is an integer from 1 to 8), and the other is a hydrogen atom. 2 )h In the substituent represented by OH, h is preferably an integer of 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0067] The method for making EVOH (a) contain the structural unit (II) is not particularly limited, and a method of making EVOH obtained by saponification react with a monovalent epoxy compound can be used. As the monovalent epoxy compound, the compounds represented by the following formulas (IV) to (X) can be used appropriately.

[0068] [Chemistry 2]

[0069]

[0070] In the above formulas (IV) to (X), R 14 , R 15 , R 16 , R 17 and R 18 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms (such as an alkyl group and an alkenyl group), an alicyclic hydrocarbon group having 3 to 10 carbon atoms (such as a cycloalkyl group and a cycloalkenyl group), or an aliphatic hydrocarbon group having 6 to 10 carbon atoms (such as a phenyl group). In addition, i, j, k, p, and q each independently represent an integer of 1 to 8.

[0071] Examples of the monovalent epoxy compound represented by the formula (IV) include ethylene oxide (ethylene oxide), propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 3-methyl-1,2-butylene oxide, 1,2-pentene oxide, 3-methyl-1,2-pentene oxide, 1,2-hexene oxide, 2,3-hexene oxide, 3,4-hexene oxide, 3-methyl-1,2-hexene oxide, 3-methyl-1,2-epoxyheptane, 4-methyl-1,2-epoxyheptane, 1,2-octane oxide, 2,3-octane oxide, 1,2-nonane oxide, 2,3-nonane oxide, 1,2-decane oxide, 1,2-dodecane oxide, ethylbenzene oxide, 1-phenyl-1,2-epoxypropylene, and 3-phenyl-1,2-epoxypropylene. As the monocyclic epoxy compound represented by the above formula (V), various alkyl glycidyl ethers and the like can be listed. As the monocyclic epoxy compound represented by the above formula (VI), various alkylene glycol monoglycidyl ethers can be listed. As the monocyclic epoxy compound represented by the above formula (VII), various alkenyl glycidyl ethers can be listed. As the monocyclic epoxy compound represented by the above formula (VIII), various oxirane alcohols such as glycidol can be listed. As the monocyclic epoxy compound represented by the above formula (IX), various epoxy cycloalkanes can be listed. As the monocyclic epoxy compound represented by the above formula (X), various epoxy cycloolefins can be listed.

[0072] Among the above-mentioned monovalent epoxy compounds, monovalent epoxy compounds having 2 to 8 carbon atoms are preferred. In particular, from the viewpoint of the ease of handling of the compound and the reactivity, the number of carbon atoms in the monovalent epoxy compound is more preferably 2 to 6, and further preferably 2 to 4. In addition, the monovalent epoxy compound is particularly preferably a compound represented by formula (IV) and a compound represented by formula (V) among the above-mentioned formulas. Specifically, from the viewpoint of the reactivity with EVOH and the gas barrier properties of the obtained laminate, 1,2-butylene oxide, 2,3-butylene oxide, propylene oxide, ethylene oxide and glycidol are preferred, and propylene oxide and glycidol are particularly preferred.

[0073] In the above structural unit (III), R 8 , R 9 , R 10 and R 11 It is preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. In particular, the aliphatic hydrocarbon group is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group.

[0074] The method for making EVOH (a) contain the structural unit (III) is not particularly limited, and for example, it can be produced by the method described in Japanese Patent Application Laid-Open No. 2014-034647.

[0075] <Metal salt of a higher fatty acid having 10 or more carbon atoms (c)>

[0076] Layer A contains a higher fatty acid metal salt (c) in an amount of 10 ppm or more and 300 ppm or less in terms of metal atoms. Here, "higher fatty acid" in this specification refers to a fatty acid having 10 or more carbon atoms. By making layer A contain a specific amount of higher fatty acid metal salt (c), it is preferred to suppress the deterioration of hue and reduce the amount of screw adhesion when the scraps of the laminate are melt-formed again for recycling. The reason why layer A contains a higher fatty acid metal salt (c) to achieve this effect is still uncertain, but it is speculated to be as follows (1) and (2). It can be speculated that: (1) It can be considered that by including a higher fatty acid metal salt (c) in EVOH (a), the amount of screw adhesion during recycling can be reduced. Even if only a higher fatty acid metal salt (c) is included in TPU (b), there is a tendency that the aforementioned reduction effect cannot be effectively exerted. (2) It can be considered that the transfer of the higher fatty acid metal salt (c) from EVOH (a) to TPU (b) is necessary to suppress the deterioration of the hue when the scraps of the laminate are melt-molded again for recycling. When a lower fatty acid metal salt is used instead of the higher fatty acid metal salt (c), the transfer of the lower fatty acid metal salt to TPU (b) becomes insufficient, and a sufficient effect of improving the hue cannot be obtained.

[0077] As the metal atom constituting the higher fatty acid metal salt (c), it can be a single metal species or a plurality of metal species. As the metal atom, a monovalent metal or a divalent metal can be listed, and from the viewpoint of improving the adhesion between the A layer and the B layer, a divalent metal is preferably used. As the divalent metal, it is preferred to include at least one selected from magnesium, manganese, tin, cobalt, zinc and titanium. Among them, it is preferred to include at least one selected from magnesium and cobalt. By including the above-mentioned metal atoms, there is a tendency for the A layer and the B layer to show higher adhesion. The reason for showing high adhesion is still uncertain, but there is a tendency that the compound containing the above-mentioned metal atoms will promote the transesterification reaction, and it can be considered that the reaction is likely to help improve adhesion.

[0078] The lower limit of the number of carbon atoms of the higher fatty acid constituting the higher fatty acid metal salt (c) is preferably 12, more preferably 13, and further preferably 14, 15, 16, 17, and 18. In addition, the upper limit of the number of carbon atoms is, for example, 30, 24, 22, or 20. As the higher fatty acid constituting the higher fatty acid metal salt (c), stearic acid, ricinoleic acid, myristic acid, lauric acid, etc. can be listed, among which stearic acid is preferred. By including the above-mentioned higher fatty acid, there is a tendency to suppress the deterioration of hue when melt-molding again for recycling the scraps of the laminate, so it is preferred.

[0079] As the higher fatty acid metal salt (c), for example, magnesium stearate, cobalt stearate, etc. can be suitably used.

[0080] The content of the higher fatty acid metal salt (c) is 10 ppm or more, preferably 20 ppm or more, and more preferably 30 ppm or more, in terms of metal atom conversion. In addition, the content of the higher fatty acid metal salt (c) is 300 ppm or less, preferably 200 ppm or less, and more preferably 100 ppm or less, in terms of metal atom conversion. If the content of the higher fatty acid metal salt (c) is less than 10 ppm in terms of metal atom conversion, there is a tendency that the hue deteriorates when the scraps of the laminate are melt-formed again in order to reuse the scraps of the laminate, and the amount of adhesion on the extruder screw increases. In addition, by setting the content of the higher fatty acid metal salt (c) to 10 ppm or more, the interlayer adhesion is also improved. If the content of the higher fatty acid metal salt (c) is more than 300 ppm in terms of metal atom conversion, there is a tendency that the hue deteriorates when the scraps of the laminate are melt-formed again in order to reuse the scraps of the laminate, and the like.

[0081] One or more additives such as phosphoric acid compounds, carboxylic acids, boron compounds, and metal salts other than higher fatty acid metal salts (c) may be added to layer A within a range that does not impair the effects of the present invention. By adding these additives to EVOH (a) and the like constituting layer A, various properties such as long-term operating performance when the laminate of the present invention is formed into a film for a long time, coloring resistance during melt molding, film forming stability, adhesion between layer A and layer B, suppression of EVOH deterioration during repeated reuse of the laminate, and appearance of the molded body can be improved.

[0082] As the phosphate compound, various acids such as phosphoric acid and phosphorous acid or their salts can be used. The phosphate can be in any form of dihydrogen phosphate, monohydrogen phosphate and phosphate. The cationic species of the phosphate is not particularly limited, and the cationic species is preferably an alkali metal or an alkaline earth metal. Among them, the phosphate compound is preferably added in the form of sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate or dipotassium hydrogen phosphate. When the A layer contains the phosphate compound, its content is preferably 1 to 500 ppm in terms of phosphate radical conversion. If the A layer contains the phosphate compound, there is a tendency that the long-term operability of the A layer is improved when the film is formed for a long time.

[0083] The carboxylic acids contained in the A layer may be carboxylate ions or carboxylic acid derivatives in addition to carboxylic acids. In addition, the carboxylic acid may be a monocarboxylic acid, a polycarboxylic acid having more than two carboxyl groups in the molecule, or a combination thereof. It should be noted that the polycarboxylic acid is preferably not a polymer. In addition, the polycarboxylate ion is formed by the detachment of at least one hydrogen ion of the carboxyl group of the polycarboxylic acid. The carboxyl group of the carboxylic acid may be esterified, and the carboxylate ion may form a salt with a metal. The carbon number of the carboxylic acid is preferably less than 10.

[0084] As monocarboxylic acid, there is no particular limitation, and examples thereof include formic acid, acetic acid, propionic acid, butyric acid, caproic acid, capric acid, acrylic acid, methacrylic acid, benzoic acid, 2-naphthoic acid, etc. These carboxylic acids may have a hydroxyl group or a halogen atom. In addition, as carboxylate ions, ions formed by the detachment of hydrogen ions of the carboxyl groups of the above-mentioned carboxylic acids may be listed. From the viewpoint of the pH adjustment ability and melt formability of the composition, the pKa of the monocarboxylic acid (including monocarboxylic acids that provide monocarboxylate ions) is preferably 3.5 or more, and more preferably 4 or more. As such monocarboxylic acids, formic acid (pKa=3.68), acetic acid (pKa=4.74), propionic acid (pKa=4.85), butyric acid (pKa=4.80), etc. may be listed, and from the viewpoint of ease of handling, acetic acid is preferred.

[0085] In addition, as a polyvalent carboxylic acid, as long as there are more than two carboxyl groups in the molecule, there is no particular limitation, and examples thereof include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, and pimelic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; tricarboxylic acids such as aconitic acid; carboxylic acids having more than four carboxyl groups such as 1,2,3,4-butanetetracarboxylic acid and ethylenediaminetetraacetic acid; hydroxycarboxylic acids such as tartaric acid, citric acid, isocitric acid, malic acid, mucic acid, succinic acid, and citramalic acid; ketocarboxylic acids such as oxaloacetic acid, pyruvic acid, 2-ketoglutaric acid, and 3-ketoglutaric acid; amino acids such as glutamic acid, aspartic acid, and 2-aminoadipic acid. It should be noted that as polyvalent carboxylate ions, their anions can be listed. Among them, from the viewpoint of easy acquisition, succinic acid, malic acid, tartaric acid, and citric acid are particularly preferred.

[0086] When the layer A contains carboxylic acids, the content thereof is preferably 0.5 μmol / g to 20 μmol / g in terms of carboxylate radical from the viewpoint of coloration resistance during melt molding.

[0087] Examples of the boron compound include boric acids, boric acid esters, borate salts, boron hydrides, etc. Specifically, examples of the boric acid include orthoboric acid (hereinafter also referred to as "boric acid"), metaboric acid, tetraboric acid, etc., examples of the boric acid esters include triethyl borate, trimethyl borate, etc., and examples of the borate salts include alkali metal salts, alkaline earth metal salts, borax, etc. of the aforementioned various boric acids. Among these compounds, orthoboric acid is preferred.

[0088] When the layer A contains a boron compound, the content thereof is preferably 20 to 2000 ppm in terms of boron element conversion from the viewpoint of improving the film formation stability of the layer A.

[0089] As metal salts other than the higher fatty acid metal salt (c), lower fatty acid metal salts having a carbon number of less than 10, metal salts of organic acids other than fatty acids, metal salts of inorganic acids, etc. can be listed. As the metal used in the metal salt, an alkali metal or an alkaline earth metal is preferred. As alkali metals, lithium, sodium, potassium, etc. can be listed, and as alkali metal salts, lower aliphatic carboxylates, aromatic carboxylates, phosphates, metal complexes, etc. of alkali metals can be listed. For example, sodium acetate, potassium acetate, sodium phosphate, potassium phosphate, sodium salt of ethylenediaminetetraacetic acid, etc. can be listed, among which sodium acetate, potassium acetate, sodium phosphate and potassium phosphate are suitable. When the A layer contains an alkali metal salt other than the higher fatty acid metal salt (c), from the viewpoint of improving interlayer adhesion, its content is preferably 20 to 1000 ppm in terms of metal atom conversion. As alkaline earth metals, beryllium, magnesium, calcium, strontium, barium, etc. can be listed, and from the viewpoint of industrial acquisition, magnesium or calcium is more preferred. As alkaline earth metal salts, lower aliphatic carboxylates, aromatic carboxylates, phosphates, metal complexes, etc. of alkaline earth metals can be listed. For example, magnesium acetate, calcium acetate, magnesium phosphate, calcium phosphate, etc. can be listed, among which magnesium acetate and calcium acetate are suitable. When layer A contains alkaline earth metal salts other than higher fatty acid metal salts (c), its content is preferably 20 to 1000 ppm in terms of metal atom conversion. By containing alkaline earth metal salts in the above range, there is a tendency for layer A and layer B to show higher adhesion. In addition, the deterioration of EVOH during repeated reuse of the laminate is suppressed, and the appearance of the molded product is improved due to the reduction of defects such as gels and particles.

[0090] Layer A may contain other resins in addition to EVOH (a) within a range that does not impair the effects of the present invention. Examples of such other resins include polyethylene, polypropylene, ethylene-propylene copolymers, ethylene or propylene copolymers (copolymers of ethylene or propylene with at least one of the following monomers: α-olefins such as 1-butene, isobutylene, 4-methyl-1-pentene, 1-hexene, 1-octene, etc.; vinyl pyrrolidones, etc.), polyolefins such as poly-4-methyl-1-pentene and poly-1-butene; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyvinylidene chloride, polyvinyl chloride, polystyrene, polycarbonate, and polyacrylate, etc.

[0091] In addition, in addition to the other resins mentioned above, layer A may also contain various ingredients such as heat stabilizers, ultraviolet absorbers, antioxidants, colorants, fillers, plasticizers, photoinitiators, deodorants, antistatic agents, lubricants, desiccants, fillers, pigments, dyes, processing aids, flame retardants, antifogging agents, etc.

[0092] 〈B layer〉

[0093] The B layer is a polyurethane layer containing TPU (b). The laminate of the present invention can exhibit excellent stretchability, bending resistance, thermoformability, etc. by having the B layer containing TPU (b).

[0094] The content of TPU (b) in layer B is preferably 60% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more. The resin constituting layer B may be 100% TPU (b).

[0095] It is preferred that the B layer contains TPU (b) because stretchability and thermoformability can be improved. In addition, the laminate of the present invention can exhibit good bending resistance due to the high adhesion between the B layer and the A layer.

[0096] TPU (b) is composed of a polymer polyol, an organic polyisocyanate, a chain extender, etc. Typically, TPU (b) is a linear multi-block copolymer of (1) a hard segment obtained by the reaction of a short-chain diol (low-molecular polyol) and an isocyanate and (2) a soft segment obtained by the reaction of a long-chain diol (polymer polyol) and an isocyanate.

[0097] A high molecular weight polyol is a substance having a plurality of hydroxyl groups, and is obtained by polycondensation, addition polymerization (e.g., ring-opening polymerization), polyaddition, etc. Examples of the high molecular weight polyol include polyester polyols, polyether polyols, polycarbonate polyols, or co-condensates thereof (e.g., polyester-ether-polyols). These high molecular weight polyols may be used alone or in combination of two or more. Among them, polyester polyols and polycarbonate polyols are preferred, and polyester polyols are particularly preferred.

[0098] The polyester polyol can be produced, for example, by directly condensing an ester-forming derivative such as a dicarboxylic acid, an ester thereof or an anhydride thereof with a low-molecular polyol through an esterification reaction or an ester exchange reaction, or by ring-opening polymerization of a lactone according to a conventional method.

[0099] Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(methyltetramethylene) glycol, etc. These polyether polyols may be used alone or in combination of two or more. Among them, polytetramethylene glycol is preferred.

[0100] As the polycarbonate polyol, for example, one obtained by polycondensing an aliphatic diol having 2 to 12 carbon atoms such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, or a mixture thereof with diphenyl carbonate or phosgene is preferably used.

[0101] The lower limit of the number average molecular weight of the above-mentioned polymer polyol is preferably 500, more preferably 600, and further preferably 700. On the other hand, the upper limit of the number average molecular weight of the polymer polyol is preferably 8,000, more preferably 5,000, and further preferably 3,000. By setting the number average molecular weight of the polymer polyol to above the above lower limit, the compatibility with the organic polyisocyanate becomes moderate, the elasticity of the obtained TPU is improved, and therefore, the mechanical properties such as the stretchability of the obtained laminate and the tendency of improved thermoforming are presented. On the contrary, by setting the number average molecular weight of the polymer polyol to below the above upper limit, the compatibility with the organic polyisocyanate is improved, and it is easy to mix during the polymerization process. As a result, the generation of gel blocks is sometimes suppressed, and stable TPU is easily obtained. It should be noted that the number average molecular weight of the polymer polyol is measured in accordance with JIS K1577 and the number average molecular weight calculated based on the hydroxyl value.

[0102] As organic polyisocyanate, there is no particular limitation, and known organic diisocyanates commonly used in the manufacture of TPU can be used, for example, 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dichloro-4,4'-diphenylmethane diisocyanate, distyrene diisocyanate and other aromatic diisocyanates; hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate and other aliphatic diisocyanates (including alicyclic diisocyanates) and the like. Among them, from the viewpoint that the strength and bending resistance of the obtained laminate can be improved, 4,4'-diphenylmethane diisocyanate is preferred. These organic diisocyanates can be used alone or in combination of two or more.

[0103] As a chain extender, a chain extender commonly used in the manufacture of TPU can be used, and a low molecular weight compound having two or more active hydrogen atoms capable of reacting with an isocyanate group and a molecular weight of 300 or less can be appropriately used. As a chain extender, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-cyclohexanediol, etc. can be listed. Among them, from the viewpoint of better stretchability and thermoformability of the obtained laminate, aliphatic diols having 2 to 10 carbon atoms are preferred, and 1,4-butanediol is particularly preferred. These chain extenders can be used alone or in combination of two or more.

[0104] As a method for producing TPU (b), the above-mentioned high molecular weight polyol, organic polyisocyanate and chain extender can be used to produce it by using a known urethanization reaction technology, or it can be produced by using any of a prepolymer method and a one-step method. Among them, it is preferred to carry out melt polymerization in the substantial absence of a solvent, and it is particularly preferred to carry out continuous melt polymerization using a multi-screw extruder.

[0105] The B layer may be composed of TPU (b) alone or may contain other resins in addition to TPU (b). In addition, the B layer may further contain other components such as a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and a filler. It should be noted that the suitable manner of the B1 layer and the B2 layer is the same as the suitable manner of the B layer except for the average thickness.

[0106] 〈D Floor〉

[0107] The D layer is a protective layer directly laminated on the B2 layer and is a layer containing TPU (x). If the laminate of the present invention contains the D layer, it tends to have improved durability and flexibility and to be able to maintain good gas barrier properties after bending. The suitable form of TPU (x) is the same as the suitable form of TPU (b) as a component of the B layer except for the content. The content of TPU (x) in the D layer is preferably 70% by mass or more, and more preferably 80% by mass or more. In addition, the content of TPU (x) in the D layer can be 100% by mass or less, preferably 99% by mass or less, and more preferably 98% by mass or less.

[0108] The D layer preferably contains EVOH (y). If the D layer contains EVOH (y), there is a tendency that the gas barrier properties after bending can be well maintained. The suitable form of EVOH (y) is the same as the suitable form of EVOH (a) as a component of the A layer except for the content. The content of EVOH (y) in the D layer is preferably 1 mass % or more and 30 mass % or less, and more preferably 2 mass % or more and 20 mass % or less.

[0109] From the viewpoint of cost reduction, the D layer is preferably a layer obtained by using recycled materials such as scraps and defective products of the laminate of the present invention.

[0110] As a method for using the scraps, defective products and other recyclables of the laminate of the present invention, there is the following method: the scraps and defective products are crushed and then put into an extruder for film making; or, after melt mixing in an extruder to make pellets, the pellets are put into an extruder again for film making. In order to control the thickness of the D layer, or in order to dilute with new TPU, it is preferred to melt mix and make pellets, and then put the pellets into an extruder again for film making.

[0111] The D layer formed by using recycled materials such as scraps and defective products of the laminate of the present invention shows a tendency that EVOH (y) is well dispersed in the matrix phase of TPU (x), and therefore, it shows a tendency to have excellent bending resistance. The reasons for showing such good dispersibility are speculated as follows. First, the laminate of the present invention has a multilayer structure, so the EVOH (a) of the A layer and the TPU (b) of the B layer are easily physically mixed during melt kneading. On the other hand, in the case of a multilayer structure and EVOH (a) and TPU (b) are easily physically mixed during melt kneading, an ester exchange reaction may occur, which has a bad effect on the dispersibility. However, in the case of the laminate of the present invention, the progress of the ester exchange reaction is moderately adjusted by the higher fatty acid metal salt (c). As a result, it can be considered that in the D layer formed by using the recycled materials of the laminate of the present invention, the dispersibility of EVOH (y) is improved. Therefore, it is preferred that the D layer also contains a higher fatty acid metal salt (z).

[0112] The content ratio x / y of TPU (x) to EVOH (y) in the D layer is preferably 70 / 30 or more, more preferably 75 / 25 or more, and further preferably 80 / 20 or more. On the other hand, the content ratio x / y is preferably 100 / 0 or less, more preferably 99 / 1 or less, and further preferably 98 / 2 or less. When the content ratio x / y is within the above range, sufficient flexibility is exhibited, and there is a tendency that the gas barrier properties after bending can be well maintained.

[0113] The total amount of TPU (x) and EVOH (y) constituting the D layer is preferably 80% by mass or more, more preferably 85% by mass or more, and further preferably 90% by mass or more. If the total amount of TPU (x) and EVOH (y) constituting the D layer is 80% by mass or more, the gas barrier properties after bending can be maintained and sufficient flexibility can be easily exhibited. The total amount of TPU (x) and EVOH (y) constituting the D layer can be 99% by mass or more.

[0114] When the D layer contains EVOH (y) and TPU (x), it is sufficient to mix TPU (x) and EVOH (y) in the phase separation structure of the D layer. Preferably, the D layer has a sea-island structure, and the main component of the sea phase is TPU (x), and the main component of the island phase (dispersed phase) is EVOH (y). Here, the main component refers to a proportion of more than 50% by mass in the phase. The proportion of TPU (x) and EVOH (y) in each layer is preferably 75% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more. When the D layer has such a phase separation structure, the bending resistance of the D layer can be further improved.

[0115] When the D layer has a sea-island structure and the main component of the island phase is EVOH (y), the lower limit of its average dispersed particle size is preferably 0.05 μm. If the average dispersed particle size is greater than 0.05 μm, there is a tendency that the recyclability is improved and it is not over-mixed. On the other hand, the upper limit is preferably 1 μm. If the average dispersed particle size is less than 1 μm, the D layer tends to have good bending resistance. Here, the average dispersed particle size refers to the particle size calculated by averaging the sizes of 10 EVOH (y) particles from large to small that fall within a particle size of 9 μm × 13 μm when observing any cross-section of the D layer with an electron microscope. When the EVOH (y) particles are in a shape other than a circle, such as an ellipse, the value of the short diameter is used for calculation. If the average dispersed particle size is within the above range, there is a tendency to show good bending resistance.

[0116] The above-mentioned average dispersed particle size can be adjusted by the mass ratio of EVOH (y) to TPU (x), the content of the higher fatty acid metal salt (z), and the kneading conditions when forming the D layer. The suitable range of the mass ratio of EVOH (y) to TPU (x) is shown above. In addition, by making the content of the higher fatty acid metal salt (z) in the D layer 0.1ppm or more and 50ppm or less in terms of metal, EVOH (y) tends to be well dispersed in the matrix phase of TPU (x). When the D layer is formed using the recycled material of the laminate of the present invention, the reason for the tendency to show excellent bending resistance can be considered to be because: there is a tendency that the mass ratio of EVOH (y) to TPU (x) and the content of the higher fatty acid metal salt (z) fall within the above range. In addition, as a method for adjusting the kneading conditions, the following methods can be listed. For example, when a single-screw extruder is used, methods such as adjusting the resin residence time or adjusting the shear viscosity by using the shape of the screw and the groove depth can be listed. As the screw shape, for example, a full helical screw, a barrier screw, etc. can be used. In order to adjust the mixing intensity, a screw with a shape such as Maddock or Dulmadge can be used. Furthermore, in order to increase the shear rate, the screw speed can be adjusted. In addition, from the viewpoint of being able to easily change the screw shape, a twin-screw extruder is sometimes used. When using a twin-screw extruder, in order to adjust the mixing intensity, a method of adjusting the length of the kneading disk can be cited.

[0117] When a single-screw extruder is used, as specific kneading conditions, for example, the lower limit of the shear rate r in the metering section of the melt extruder calculated by the following general formula (1) is preferably 10 sec. -1 , preferably 15 sec -1 , particularly preferably 20 sec -1 In addition, the upper limit of the shear rate r is preferably 100 sec. -1 , preferably 95 sec -1, particularly preferably 90 sec -1 If kneading is performed at or above the above lower limit, the EVOH (a) of layer A and the TPU (b) of layer B in the laminate of the present invention are appropriately mixed, and the average dispersed particle size can be adjusted to an appropriate range, so that the bending resistance tends to be good. On the other hand, if kneading is performed at or above the above upper limit, EVOH (a) and TPU (b) are sometimes excessively mixed, the average dispersed particle size becomes smaller, and the thermal stability deteriorates.

[0118] [Mathematical formula 1]

[0119]

[0120] In the above general formula (1), D represents the barrel diameter (cm), N represents the screw speed (rpm), h represents the groove depth of the metering part (cm), and r represents the shear rate (sec -1 ).

[0121] 〈Purpose, etc.〉

[0122] The laminate of the present invention is excellent in interlayer adhesion, appearance, and gas barrier properties after bending, and can therefore be used for food packaging materials, medical container packaging materials, other container packaging materials, industrial sheets, building material sheets, agricultural sheets, geological treatment films, radon barrier films, other sheets, other various pipes, etc. In particular, the laminate of the present invention can be suitably used as a gas barrier film laminated on film-like rubber products such as tire inner liners, shoe sole air cushioning materials, accumulator inner bags, inflatable balls, and air springs.

[0123] <Method for producing laminated body>

[0124] The method for producing the laminate of the present invention is not particularly limited as long as the A layer and the B layer are laminated and bonded to each other in a satisfactory manner, and a known method such as coextrusion, lamination, coating, bonding, and adhesion can be used.

[0125] The laminate of the present invention can be preferably produced by a production method including a step of coextruding a resin forming layer A and a resin forming layer B. This production method has high productivity, can obtain excellent interlayer adhesion between layer A and layer B, and is also excellent in recyclability.

[0126] In the multilayer coextrusion method, the resin forming the A layer and the resin forming the B layer are heated and melted, and supplied to the extrusion die through respective flow paths from different extruders and pumps, and extruded into multiple layers from the extrusion die, and then laminated and bonded to form the laminate of the present invention. As the extrusion die, for example, a multi-manifold die, a feed block, a static mixer, etc. can be used.

[0127] It should be noted that the relationship between the viscosities of the resins forming the A layer and the B layer is preferably the following melt viscosity ratio. That is, the melt viscosity (η) of the resin forming the A layer at a temperature of 210° C. and a shear rate of 1,000 / sec is: A ) and the melt viscosity (η B ) ratio (η B / η A The lower limit of ) is preferably 0.3, more preferably 0.5. On the other hand, the melt viscosity ratio (η B / η A The upper limit of ) is preferably 2, more preferably 1.5. B / η A ) is set to the above range, so that in the molding of the laminate of the present invention based on the multilayer co-extrusion method, the appearance becomes good, and in addition, the adhesion between the A layer and the B layer becomes good, which can improve the durability of the laminate of the present invention.

[0128] When the laminate of the present invention has a layer other than layer A and layer B, such as layer D, it can also be manufactured according to the above method. That is, each layer can be laminated by a known method such as coextrusion, pasting, coating, bonding, and adhesion, among which coextrusion is preferred.

[0129] The method for manufacturing a laminate of the present invention may include a step of irradiating the structure (laminated body) obtained by coextrusion with electron beams. By irradiating electron beams, a cross-linking reaction between layers occurs, and the interlayer adhesion of the obtained laminate can be improved. As an electron beam source, various electron beam accelerators such as Cockcroft-Walton type, Van de Graaff type, resonance transformer type, insulating core transformer type, high frequency high voltage type, and high frequency type can be used. Example

[0130] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[0131] <Materials used>

[0132] EVOH-1: "Eval (registered trademark) E105B" (manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer, ethylene unit content 44 mol%)

[0133] EVOH-2: "Eval (registered trademark) F101B" (manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer, ethylene unit content 32 mol%)

[0134] EVOH-3: "Eval (registered trademark) L171B" (manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer, ethylene unit content: 27 mol%)

[0135] EVOH-4: "Eval (registered trademark) G156B" (manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer, ethylene unit content 48 mol%)

[0136] TPU-1: "Estane (registered trademark) 2103-90AE" (manufactured by Lubrizol, thermoplastic polyurethane).

[0137] <Evaluation method>

[0138] (1) Interlayer adhesion between layer A and layer B

[0139] The laminates obtained in each example and comparative example were stored in an atmosphere of 23°C and 50% RH, and short strips of 15 mm were prepared on the next day of production as test samples. Using the test sample, the T-peel strength was measured at a tensile speed of 250 mm / min using an Autograph "AGS-H" manufactured by Shimadzu Corporation in an atmosphere of 23°C and 50% RH. The obtained value (unit: g / 15 mm) was used as the interlayer adhesion between layer A and layer B, and the interlayer adhesion was evaluated based on the following evaluation criteria.

[0140] Judgment: Benchmark

[0141] A: 700g / 15mm or more

[0142] B: less than 700g / 15mm and more than 500g / 15mm

[0143] C: less than 500g / 15mm and more than 300g / 15mm

[0144] D: less than 300g / 15mm.

[0145] (2) Appearance

[0146] The appearance of the laminated body obtained in each of the Examples and Comparative Examples was evaluated by visual inspection based on the following evaluation criteria.

[0147] Judgment: Benchmark

[0148] A: No lines or stripes, good appearance

[0149] B: Lines are slightly observed relative to the flow direction of the film

[0150] C: Lines are observed relative to the flow direction of the membrane

[0151] D: Lines and streaks are observed relative to the flow direction of the film.

[0152] (3) Gas barrier properties after bending (bending resistance)

[0153] The laminates obtained in the examples and comparative examples were bent repeatedly 50 times in an environment of 23°C using the "BE1006 Gelbo-Francis tester with constant temperature chamber" manufactured by Tester Industries, Ltd. in accordance with ASTM-F392-74. The gas barrier properties of the laminates before and after bending were evaluated as described below. Specifically, the laminates obtained in the examples and comparative examples were humidified at 20°C and 65%RH for 5 days, and the oxygen permeability was measured using the "MOCON OX-TRAN2 / 20" produced by MOCON at 20°C and 65%RH according to the method described in JIS K 7126-2 (isobaric method; 2006), and the average value (unit: mL / (m 2 ・day・atm)). It should be noted that if the oxygen permeability is 300mL / (m 2 ・day・atm) or less, then under 1 atmosphere pressure, the 2 The oxygen permeability was 300 mL or less within 1 day, so it was evaluated as having gas barrier properties. The oxygen permeability before bending was defined as OTR0, and the oxygen permeability after bending was defined as OTR50, and OTR0 / OTR50 was evaluated based on the following criteria.

[0154] Judgment: Benchmark

[0155] A: OTR0 / OTR50≥0.9

[0156] B: 0.9>OTR0 / OTR50≥0.8

[0157] C: 0.8>OTR0 / OTR50≥0.7

[0158] D:0.7>OTR0 / OTR50.

[0159] (4) Recycling test (coloring)

[0160] 60 g of the laminate obtained in the examples and comparative examples was cut (about 1 cm × 1 cm) in a manner that fits the inlet of a Labtoplast Mill (manufactured by Toyo Seiki Seisaku-sho, Ltd., "20R200" biaxial anisotropic), and kneaded at 60 rpm and 200° C. for 30 minutes to prepare a disc-shaped sample with a thickness of 2 mm. The coloring state of the obtained disc-shaped sample was visually confirmed and judged as follows.

[0161] Judgment: Benchmark

[0162] A: Almost no coloring

[0163] B: Slightly colored

[0164] C: Coloring (light yellow)

[0165] D: Coloration (yellow).

[0166] (5) Recycling test (screw attachment amount)

[0167] 60 g of the laminate obtained in the examples and comparative examples was cut (about 1 cm × 1 cm) in a manner that fits the inlet of a Labo Plastic Mill (manufactured by Toyo Seiki Seisaku-sho, Ltd., "20R200" biaxial anisotropic), kneaded at 60 rpm and 200°C for 30 minutes, and the kneaded resin was collected. Thereafter, 60 g of "low-density polyethylene manufactured by Japan Polyethylene Co., Ltd.; LDPE Nobatek LJ400" was kneaded at 200°C for 30 minutes in a Labo Plastic Mill, and the LDPE was collected. Thereafter, the burnt material attached to the screw was collected and its weight was measured. Evaluation was performed based on the following criteria.

[0168] Judgment: Evaluation

[0169] A: 0.5g> screw attachment amount

[0170] B: 2.5g> screw attachment amount ≥ 0.5g

[0171] C: 5.0g> screw attachment amount ≥ 2.5g

[0172] D: Screw attachment amount ≥5.0g.

[0173] (6) Recycling test (average dispersed particle size)

[0174] 2 kg of the laminated bodies obtained in the examples and comparative examples were cut (approximately 1 cm × 1 cm) in a manner consistent with the inlet of a 20 mm extruder "D2020" manufactured by Toyo Seiki Seisaku-sho (D (mm) = 20, L / D = 20, compression ratio = 2.0, screw: full spiral), and strands were extruded under the following conditions. After cooling by air cooling, pellets of the recycled product of the laminated body were prepared using a pelletizer.

[0175] 〈Pellet production conditions〉

[0176] Extrusion temperature supply unit / compression unit / metering unit / die

[0177] =180 / 210 / 210 / 210℃

[0178] Screw speed 40rpm

[0179] Spray volume 1.3kg / hr

[0180] Die hole number 2 holes

[0181] The obtained recycled pellets were subjected to single-layer film formation under the following conditions using a 20 mm extruder "D2020" manufactured by Toyo Seiki Seisaku-sho (D (mm) = 20, L / D = 20, compression ratio = 2.0, screw: full spiral) to obtain a single-layer film.

[0182] 〈Film Forming Conditions〉

[0183] Extrusion temperature: supply part / compression part / metering part / die

[0184] =180 / 200 / 200 / 200℃

[0185] Screw speed: 40rpm

[0186] Spray volume: 1.3kg / hr

[0187] Pulling roller temperature: 80℃

[0188] Pulling roller speed: 1.0m / min.

[0189] Film thickness: 60μm

[0190] The obtained single-layer film was cut along the TD direction using a slicer to prepare slices for cross-sectional observation. The prepared slices were fixed to the sample base with carbon tape and subjected to platinum ion sputtering at an accelerating voltage of 30 kV for 30 seconds. A field-release transmission electron microscope [device: SU8000 manufactured by Hitachi High-Tech Nologis Co., Ltd.] was used to observe the cross-section of the single-layer film and calculate the average dispersed particle size. Regarding the measurement conditions, the acceleration voltage: 1 kV, the magnification: 20,000 times. Using an electron microscope, the sizes of 10 EVOH particles from large to small in the particle size falling within the observation area of ​​9 μm × 13 μm were calculated as the average dispersed particle size, and the evaluation was performed based on the following criteria.

[0191] Judgment: Evaluation

[0192] A: 0.5μm> average particle size ≥ 0.05μm

[0193] B: 1.0μm> average particle size ≥ 0.5μm

[0194] C: 1.5 μm > average particle size 1.0 μm

[0195] D: Average particle size ≥ 1.5 μm.

[0196] (7) Recycling test (bending resistance)

[0197] The single-layer film prepared in the recycling test (average dispersed particle size) of the above evaluation method (6) was cut into an A4 size (TD 210 mm × MD 297 mm), and was repeatedly bent 1000 times in an environment of 23°C using a Gelber-Franks tester manufactured by Tester Industries, Ltd. in accordance with ASTM-F392-74. The number of pinholes after bending was measured. It should be noted that the number of pinholes within the A4 (210 mm × 297 mm) range was evaluated based on the following criteria.

[0198] Judgment: Evaluation

[0199] A: Number of pinholes ≤ 1

[0200] B: 2 ≤ Number of pinholes ≤ 5

[0201] C: 6 ≤ pinholes ≤ 10

[0202] D: 11 ≤ the number of pinholes.

[0203] <Example 1>

[0204] Magnesium stearate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was dry-blended into Eval (registered trademark) E105B (EVOH-1) in an amount of 70 ppm in terms of Mg conversion, and melt granulated using a twin-screw extruder (diameter 25 mm, L / D = 25) manufactured by Toyo Seiki Seisaku-sho, Ltd., at a screw speed of 100 rpm and a discharge of 6.5 kg / hr to produce EVOH containing a metal salt. The obtained EVOH containing a metal salt and Estane 2103-90AE (TPU-1) were used as materials and supplied to a co-extruder having a 19-layer feed block in a molten state at 190°C for co-extrusion, thereby producing a laminate having a total of 19 layers in which 9 EVOH layers and 10 TPU layers were alternately laminated.

[0205] The obtained laminate was observed in cross section using "DIGITAL MICROSCOPE VK-X200" manufactured by KEYENCE. As a result, the average thickness of each layer A (EVOH layer) was 1.1 μm, and the average thickness of each layer B (TPU layer) was 3.3 μm. It should be noted that each thickness is the average value of the measured values ​​at 10 randomly selected points.

[0206] The obtained laminate was evaluated according to the above (1) to (7). The evaluation results are shown in Table 1. It should be noted that the interlayer adhesion of the obtained laminate was 890 g / 15 mm, the appearance had no lines or streaks, and the appearance was good. The OTR before bending (OTR0) was 3.0 mL / (m 2 ・day・atm)、The OTR after bending (OTR50) is 3.2mL / (m2 ・day・atm), OTR0 / OTR50 was 0.94, and in the coloration test during recycling, there was almost no coloration. The screw attachment amount during recycling was 0.2g, the average dispersed particle size of EVOH in the recycling test was 0.38μm, and in the bending resistance test, there were 0 pinholes.

[0207] <Example 2 to Example 24, Comparative Examples 1 to 6>

[0208] A laminate was prepared and evaluated in the same manner as in Example 1 except that the type of EVOH, the type of metal salt, the amount of metal salt added, the number of layers of the A layer, the average thickness of each layer of the A layer, the type of TPU, the amount of metal salt added to the B layer, the number of layers of the B layer, and the average thickness of each layer of the B layer were changed as shown in Tables 1 to 3. The evaluation results are shown in Tables 1 to 3.

[0209]

[0210]

[0211]

[0212] In Example 1, by appropriately adjusting the metal atom equivalent amount of the higher fatty acid metal salt (c), the metal salt and the metal type, and alternately laminating the gas barrier layer (A) and the polyurethane layer (B), and appropriately adjusting the number of layers, thickness, and the ratio of the average thickness of each gas barrier layer (A) to the average thickness of each polyurethane layer (B) (gas barrier layer (A) / polyurethane layer (B)), a laminate having excellent recyclability while maintaining good interlayer adhesion, appearance, and gas barrier properties after bending of the laminate can be obtained. In Examples 2 to 7, by adjusting the metal atom equivalent amount of the higher fatty acid metal salt (c), a laminate having excellent interlayer adhesion, appearance, and recyclability of the laminate can be obtained, although it is slightly inferior to that of Example 1. Based on these results, it can be considered that when the content of the higher fatty acid metal salt (c) is large or small, there is a tendency for recyclability, appearance, or adhesion to deteriorate. In Examples 8 to 11, by adjusting the type of higher fatty acid and the type of metal in the higher fatty acid metal salt (c), a laminate having excellent recyclability, although slightly inferior to that in Example 1, can be obtained. From these results, it can be considered that if the number of carbon atoms of the higher fatty acid constituting the higher fatty acid metal salt (c) decreases, there is a tendency for the recyclability to deteriorate. In Examples 12 to 14, by adjusting the ethylene unit content of the ethylene-vinyl alcohol copolymer (a), a laminate having good gas barrier properties after bending, although equivalent to or slightly inferior to that in Example 1, can be obtained. From these results, it can be considered that when the ethylene unit content is small, there is a tendency for the gas barrier properties after bending to deteriorate. In Examples 15 to 24, by adjusting the average thickness of each gas barrier layer (A), the average thickness of each polyurethane layer (B), and the ratio of the average thickness of each gas barrier layer (A) to the average thickness of each polyurethane layer (B) (gas barrier layer (A) / polyurethane layer (B)), a laminate having excellent interlayer adhesion, gas barrier properties after bending, and recyclability, although slightly inferior to Example 1, can be obtained. Based on these results, it can be considered that the interlayer adhesion, gas barrier properties after bending, and recyclability are affected by the film thickness, number of layers, and film thickness ratio of each layer. On the other hand, as in Comparative Examples 1 to 4, when the type and amount of the metal salt contained in the gas barrier layer (A) are not appropriate, there is a tendency for the interlayer adhesion and recyclability to deteriorate.

[0213] In addition, when comparing Comparative Example 3 (19 layers) and Comparative Example 6 (3 layers), both of which contain AcOMg in the A layer but differ only in the number of layers, the evaluations of coloration and screw adhesion in the recycling test of Comparative Example 3 are both D, while those of Comparative Example 6 are both C. That is, it can be seen that the deterioration of the color of the resin during melt kneading for recycling and the adhesion of the degraded resin to the screw in the melt molding machine are phenomena that occur significantly when the number of layers is large. Furthermore, when comparing Example 1 (19 layers) and Comparative Example 5 (3 layers), both of which contain StMg in the A layer but differ only in the number of layers, the evaluations of coloration and screw adhesion in the recycling test of Example 1 are both A, while those of Comparative Example 5 are both B. That is, when the A layer contains a predetermined amount of a higher fatty acid metal salt, unlike the case of a lower fatty acid metal salt, the result of improving recyclability by making a multilayer structure is shown.

[0214] <Example 25>

[0215] A laminate was prepared in the same manner as in Example 1 except that the average thickness of the layer corresponding to the polyurethane layer (B1) was adjusted to 3.3 μm and the average thickness of the layer corresponding to the polyurethane layer (B2) was adjusted to 20 μm. The interlayer adhesion of the obtained laminate was 850 g / 15 mm, the appearance was good without lines or streaks, and the OTR before bending (OTR0) was 3.0 mL / (m 2 ・day・atm) and the OTR after bending (OTR50) is 3.1mL / (m 2 ・day・atm), OTR0 / OTR50 was 0.97, and in the coloring test during recycling, there was almost no coloring, the screw attachment amount during recycling was 0.1g, the average dispersed particle size of EVOH in the recycling test was 0.41μm, and in the bending resistance test, there were 0 pinholes. As in Example 1, a laminate with excellent recyclability and good interlayer adhesion, appearance, and gas barrier properties after bending of the laminate was obtained.

[0216] <Example 26>

[0217] Magnesium stearate manufactured by FUJIFILM Wako Pure Chemical Corporation was dry-blended into Eval (registered trademark) E105B (EVOH-1) to reach 70 ppm in terms of the amount of Mg conversion, and melt granulation was carried out using a twin-screw extruder (caliber 25 mm, L / D = 25) manufactured by Toyo Seiki Seisakusho under the conditions of a screw rotation speed of 100 rpm and an ejection rate of 6.5 kg / hr to produce EVOH containing a metal salt. As the protective layer (D) directly laminated on the outside of the polyurethane layer (B2) in Example 25, a resin composition of TPU-1: EVOH containing a metal salt = 95:5 was used, and a two-layer protective layer (D) was provided by coextrusion to manufacture a laminate with a total of 21 layers. Except for this, the laminate was produced in the same manner as in Example 25 and evaluated. The average thickness of each layer of the protective layer (D) was 500 μm. The interlayer adhesion of the obtained laminate was 930 g / 15 mm, the appearance had no lines or streaks, and it was a good appearance. The OTR before bending (OTR0) was 3.0 mL / (m 2 ·day·atm), the OTR after bending (OTR50) was 3.1 mL / (m 2 ·day·atm), the OTR0 / OTR50 was 0.97. In the coloring test during reuse, almost no coloring occurred, the amount of adhesion to the screw during reuse was 0.06 g, the average dispersion particle size of EVOH in the reuse test was 0.40 μm, and in the flex resistance test, the number of pinholes was 0. A laminate that can well maintain the interlayer adhesion, appearance, and gas barrier property after bending of the laminate and has excellent reusability can be obtained.

[0218] <Example 27>

[0219] The laminate obtained in Example 1 was cut (about 1 cm × 1 cm) to fit the inlet of a 20 mm extruder "D2020" (D (mm) = 20, L / D = 20, compression ratio = 2.0, screw: full thread) manufactured by Toyo Seiki Seisakusho, and together with TPU-1 pellets, it was put into the extruder so that the resin ratio in the obtained recycled pellets reached TPU-1: EVOH-1 = 95:5. The wire was extruded under the following conditions, cooled by air cooling, and then pellets were produced using a granulator.

[0220] 〈Pellet production conditions〉

[0221] Extrusion temperature Supply section / Compression section / Metering section / Die

[0222] = 180 / 210 / 210 / 210 °C

[0223] Screw rotation speed 40 rpm

[0224] Ejection rate 1.3 kg / hr

[0225] Die hole number 2 holes

[0226] As the protective layer (D) directly laminated on the outside of the polyurethane layer (B2) of Example 26, the pellets obtained above were used. A laminate was prepared in the same manner as in Example 26 and evaluated. The average thickness of each protective layer (D) was 500 μm. The interlayer adhesion of the obtained laminate was 920 g / 15 mm, and the appearance was good without lines or streaks. The OTR before bending (OTR0) was 3.0 mL / (m 2 ・day・atm)、The OTR after bending (OTR50) is 3.2mL / (m 2 ・day・atm), OTR0 / OTR50 is 0.94, there is almost no coloring in the coloring test during recycling, the screw attachment amount during recycling is 0.2g, the average dispersed particle size of EVOH in the recycling test is 0.38μm, and there is 1 pinhole in the bending resistance test. A laminate with excellent recyclability and good interlayer adhesion, appearance, and gas barrier properties after bending of the laminate can be obtained.

[0227] In addition, the laminate obtained in Example 27 was cut along the TD direction using a slicer to prepare slices for cross-sectional observation. The prepared slices were fixed to the sample base with carbon tape and subjected to platinum ion sputtering at an acceleration voltage of 30 kV for 30 seconds. A field release transmission electron microscope [device: SU8000 manufactured by Hitachi High-Tech Nologis Co., Ltd.] was used to observe the cross section of the D layer in the laminate, and the average dispersed particle size was calculated. Regarding the measurement conditions, the acceleration voltage: 1 kV, the magnification: 20,000 times. Using an electron microscope, the sizes of 10 EVOH particles from large to small among the particle sizes falling within the observation area of ​​9 μm×13 μm were calculated as the average dispersed particle size. As a result, the particle size of EVOH in the D layer was 0.45 μm.

[0228] Furthermore, the laminate obtained in Example 27 was cut into an A4 size (TD 210 mm × MD 297 mm), and was repeatedly bent 1000 times in an environment of 23° C. using a Gelber-Francis tester manufactured by Tester Industries, Ltd. in accordance with ASTM-F392-74. As a result of measuring the number of pinholes after bending, the number of pinholes was 1.

[0229] Industrial Applicability

[0230] The laminate of the present invention can be used as a material requiring gas barrier properties, durability, elasticity, etc., such as food packaging materials, medical container packaging materials, other container packaging materials, industrial sheets, building material sheets, agricultural sheets, geological treatment films, radon barrier films, other sheets, other various pipes, etc. In particular, the laminate of the present invention can be appropriately used as a material such as a gas barrier film laminated on a film-like rubber product such as a tire inner liner, a shoe sole air cushioning material, an accumulator inner bag, an inflatable ball, and an air spring, and can effectively reuse useless parts such as scraps.

Claims

1. A laminate comprising: a gas barrier layer A comprising an ethylene-vinyl alcohol copolymer a; and a polyurethane layer B comprising a thermoplastic polyurethane b, The laminate comprises a structure in which at least one set of gas barrier layer A and polyurethane layer B are directly laminated, the total number of gas barrier layer A layers and polyurethane layer B layers is 9 or more and 300 or less, the gas barrier layer A contains 10 ppm or more and 300 ppm or less of a higher fatty acid metal salt c having 10 or more carbon atoms in terms of metal atoms, Gas barrier layers A and polyurethane layers B are alternately laminated.

2. The laminate according to claim 1, in, The metal atom constituting the higher fatty acid metal salt c contains at least one selected from magnesium and cobalt.

3. The laminate according to claim 2, in, The higher fatty acid metal salt c contains at least one selected from magnesium stearate and cobalt stearate.

4. The laminate according to any one of claims 1 to 3, in, The ethylene unit content of the ethylene-vinyl alcohol copolymer a is 20 mol% or more and 60 mol% or less.

5. The laminate according to any one of claims 1 to 3, in, The polyurethane layer B includes a polyurethane layer B1 on both surfaces of which the gas barrier layer A is directly laminated, and a polyurethane layer B2 on only one surface of which the gas barrier layer A is directly laminated. 6 . The laminate according to claim 5 , comprising a protective layer D directly laminated on the polyurethane layer B2 , wherein the protective layer D comprises thermoplastic polyurethane x.

7. The laminate according to claim 6, in, The protective layer D contains ethylene-vinyl alcohol copolymer y.

8. The laminate according to claim 6, in, The average thickness of each protective layer D is 300 μm or more and 800 μm or less.

9. The laminate according to any one of claims 1 to 3, in, The average thickness of the gas barrier layer A per layer is 0.1 μm or more and 10 μm or less.

10. The laminate according to any one of claims 1 to 3, in, The average thickness of the polyurethane layer B per layer is 0.1 μm or more and 30 μm or less.

11. The laminate according to any one of claims 1 to 3, in, The ratio of the average thickness per layer of the gas barrier layer A to the average thickness per layer of the polyurethane layer B, that is, gas barrier layer A / polyurethane layer B, is 0.1 or more and 1 or less.

Images