Coextruded multilayer film, laminated film, and application thereof

Abstract

The present invention addresses the problem of providing a multilayer film having high interlayer adhesion even when a layer containing a thermoplastic polyurethane resin elastomer is laminated on another resin layer. The present invention relates to a multilayer film comprising: a layer (a) mainly composed of a thermoplastic urethane resin; and a layer (b) mainly composed of a resin other than the thermoplastic urethane resin. The thermoplastic urethane resin is a thermoplastic polyurethane resin elastomer having a structural unit derived from an isocyanate compound (I), a structural unit derived from an aliphatic alcohol (II), and a structural unit derived from a polyol (III). The isocyanate compound (I) contains 90 mol% or more in total of an aliphatic isocyanate compound containing two isocyanate groups and an alicyclic isocyanate compound containing two isocyanate groups.

Description

Co-extruded multilayer films, laminated films and their applications

[0001] This invention relates to co-extruded multilayer films, laminated films, and their applications.

[0002] Thermoplastic polyurethane elastomers (TPU) possess superior mechanical strength, elastic properties, abrasion resistance, and oil resistance compared to other thermoplastic resins (TPEs), such as polyester-based (TPEE), polyamide-based (TPAE), styrene-based (SBC), olefin-based (TPO), and polyvinyl chloride-based (TPVC). Therefore, molded products such as films, sheets, tubes, and pipes produced from TPU by extrusion molding, as well as various molded products obtained by injection molding, are used in a wide range of applications.

[0003] TPU is generally obtained by reacting diisocyanate compounds, short-chain diols, and long-chain diols. Among these, TPU using aromatic 4,4'-diphenylmethane diisocyanate (MDI) as the isocyanate compound and 1,4-butanediol (1,4BG) as the chain extender is the most widely used. As for long-chain diols, polyester-based, polyether-based, and polycarbonate diol-based diols are known.

[0004] For example, Patent Document 1 proposes a thermoplastic polyurethane resin elastomer that has shape memory properties at room temperature or above, based on a polycarbonate diol derived from 1,6-hexanediol, characterized by the use of a chain extender having an aromatic group. Patent Document 2 also proposes a thermoplastic polyurethane resin elastomer with improved flexibility, strength, and water resistance, using a main component obtained by reacting a polycarbonate polyol, a polyether polyol, and an aromatic polyisocyanate compound, and a curing agent such as 1,4-butanediol.

[0005] Furthermore, Patent Document 3 describes a thermoplastic polyurethane resin elastomer obtained by reacting an isocyanate compound (I) with an aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from its hydroxyl value and having only hydroxyl groups as functional groups, and a polyol (III) having a number average molecular weight of 300 or more and 10,000 or less as determined from its hydroxyl value.

[0006] Japanese Patent Publication No. 2004-59706, Japanese Patent Publication No. 2015-81278, International Publication No. 2020 / 218507

[0007] However, when a sheet is formed from thermoplastic polyurethane resin elastomer, it has the disadvantage of having a low tensile storage modulus and poor handling properties. On the other hand, when a layer containing thermoplastic polyurethane resin elastomer is laminated with other resin layers, the interlayer adhesion may not be sufficiently achieved, which has been a problem.

[0008] Furthermore, sheets formed from thermoplastic polyurethane resin elastomers sometimes require excellent tensile properties, and improvements in this area were also needed.

[0009] Therefore, in order to solve the problems of the conventional technology, the present inventors have conducted research with the aim of providing a multilayer film that has high interlayer adhesion and excellent tensile properties, even when a layer containing a thermoplastic polyurethane resin elastomer is laminated with other resin layers.

[0010] Examples of specific embodiments of the present invention are shown below.

[0011] [1] A co-extruded multilayer film having a layer (a) mainly composed of a thermoplastic urethane resin and a layer (b) mainly composed of a resin other than a thermoplastic urethane resin, wherein the resin constituting layer (b) is at least one selected from polyester resins and polycarbonate resins, the total thickness of layer (a) is 30 μm or more and 500 μm or less, the total thickness of layer (b) is 3 μm or more and 500 μm or less, the ratio of the total thickness of layer (a) to the total thickness of layer (b) (a / b) is 0.7 or more and less than 19, and the tensile storage modulus in at least one direction at 23°C is 200 MPa or more and 1700 MPa or less. [2] The co-extruded multilayer film according to [1], wherein the ratio of the total thickness of layer (a) to the total thickness of layer (b) (a / b) is 1 or more and less than 19. [3] The thermoplastic polyurethane resin elastomer is a thermoplastic polyurethane resin having structural units derived from an isocyanate compound (I), structural units derived from an aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from the hydroxyl value and having only hydroxyl groups as functional groups, and structural units derived from a polyol (III) having a number average molecular weight of 300 or more and 10,000 or less as determined from the hydroxyl groups, wherein the isocyanate compound (I) contains a total of 90 mol% or more of aliphatic isocyanate compounds containing two isocyanate groups and alicyclic isocyanate compounds containing two isocyanate groups in a co-extruded multilayer film according to [1] or [2]. [4] The aliphatic alcohol (II) contains 90 mol% or more of aliphatic diols having 12 or fewer carbon atoms in the co-extruded multilayer film according to [3]. [5] The co-extruded multilayer film according to [3] or [4], wherein the polyol (III) comprises 80 mol% or more of polycarbonate diol (IIIA) containing repeating structural units represented by the following formula (A) and / or repeating structural units represented by the following formula (B). (In formula (A), R １ R is a hydrocarbon group having 3 to 5 carbon atoms, in formula (B), ２(I is a hydrocarbon group having 6 to 20 carbon atoms.) [6] A co-extruded multilayer film according to any one of [3] to [5], wherein the hydroxyl group equivalent (EIII) of polyol (III): isocyanate equivalent (EI) of isocyanate compound (I): hydroxyl group equivalent (EII) of aliphatic alcohol (II) is in an equivalent ratio of 1.0:2.0 to 6.0:1.0 to 5.0, and the equivalent ratio of 0.95 ≤ (EI) / ((EII) + (EIII)) ≤ 1.05. [7] A co-extruded multilayer film according to [5], wherein the number average molecular weight obtained from the hydroxyl value of polycarbonate diol (IIIA) is 500 or more and 5,000 or less. [8] A co-extruded multilayer film according to any one of [3] to [7], wherein the thermoplastic polyurethane resin elastomer contains 10% by mass or more of structural units derived from biomass resources. [9] A co-extruded multilayer film according to any one of [1] to [8], wherein the polyester resin or polycarbonate resin contains structural units derived from biomass resources.

[10] A co-extruded multilayer film according to any one of [1] to [9], wherein the tensile break elongation in at least one direction at 23°C is 150% or more.

[11] A co-extruded multilayer film according to any one of [1] to

[10] , wherein the puncture impact strength at 23°C is 3.0 J or more.

[12] A laminated film further having a printed layer on at least one surface of the co-extruded multilayer film according to any one of [1] to

[11] .

[13] An automotive exterior film having the co-extruded multilayer film according to any one of [1] to

[11] .

[14] An interior and exterior decorative film having the co-extruded multilayer film according to any one of [1] to

[11] .

[15] An interior synthetic leather sheet having the co-extruded multilayer film according to any one of [1] to

[11] .

[0012] According to the present invention, even when a layer containing a thermoplastic polyurethane resin elastomer is laminated with other resin layers, a multilayer film with high interlayer adhesion and excellent tensile properties can be obtained.

[0013] Figure 1 is a cross-sectional view illustrating the structure of the co-extruded multilayer film according to this embodiment.

[0014] Hereinafter, the present invention will be described in detail. The following description may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it means "X or more and Y or less", and also includes the meaning of "preferably larger than X" or "preferably smaller than Y". Further, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it also includes the intention of "preferably larger than X" or "preferably less than Y". In the following description, "film" and "sheet" are not clearly distinguished, and when referred to as "film", it includes "sheet", and when referred to as "sheet", it includes "film".

[0015] (Coextruded multilayer film) This embodiment relates to a coextruded multilayer film having a layer (a) mainly composed of a thermoplastic urethane resin and a layer (b) mainly composed of a resin other than the thermoplastic urethane resin. In this embodiment, the resin constituting the layer (b) is at least one selected from polyester resins and polycarbonate resins. The total thickness of the layer (a) is 30 μm or more and 500 μm or less, the total thickness of the layer (b) is 3 μm or more and 500 μm or less, and the ratio (a / b) of the total thickness of the layer (a) to the total thickness of the layer (b) is 0.7 or more and less than 19. Further, the tensile storage modulus in at least one direction at 23°C of the coextruded multilayer film of this embodiment is 200 MPa or more and 1700 MPa or less.

[0016] The tensile storage modulus in at least one direction at 23°C of the co-extruded multilayer film of this embodiment is preferably 200 MPa or more, more preferably 250 MPa or more, even more preferably 300 MPa or more, even more preferably 350 MPa or more, even more preferably 400 MPa or more, even more preferably 450 MPa or more, and particularly preferably 500 MPa or more. Furthermore, the tensile storage modulus in at least one direction at 23°C of the co-extruded multilayer film is preferably 2000 MPa or less, more preferably 1900 MPa or less, even more preferably 1800 MPa or less, even more preferably 1700 MPa or less, even more preferably 1600 MPa or less, and particularly preferably 1500 MPa or less. More specifically, it is preferable that the tensile storage modulus of the co-extruded multilayer film in the mechanical flow direction (MD) and / or width direction (TD) is within the above range, and it is more preferable that the tensile storage modulus of the co-extruded multilayer film in the mechanical flow direction (MD) and width direction (TD) is within the above range. The tensile storage modulus of the co-extruded multilayer film in the mechanical flow direction (MD) and width direction (TD) is the value (tensile storage modulus E') measured in tensile mode at a vibration frequency of 10 Hz using a rheometer (TA Instruments, "DiscoveryHR2") in accordance with JIS K7244-10 (2005).

[0017] The thickness of layer (a), which mainly consists of thermoplastic urethane resin, is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 40 μm or more, and particularly preferably 50 μm or more. Furthermore, the thickness of layer (a), which mainly consists of thermoplastic urethane resin, is preferably 800 μm or less, more preferably 700 μm or less, even more preferably 600 μm or less, even more preferably 500 μm or less, even more preferably 450 μm or less, and particularly preferably 400 μm or less. By setting the thickness of layer (a) to be above the lower limit, film formation stability, abrasion resistance, tensile break elongation, and impact resistance can be more effectively improved. Furthermore, by setting the thickness of layer (a) to be below the upper limit, it becomes easier to improve the transparency of layer (a). In the co-extruded multilayer film of this embodiment, layer (a), which mainly consists of thermoplastic urethane resin, may be a base layer. In this case, the thickness of layer (a), which mainly consists of thermoplastic urethane resin, is preferably equal to or greater than the thickness of layer (b), which mainly consists of a resin other than thermoplastic urethane resin, as described later, and it is preferable that layer (a) is the main layer.

[0018] The thickness of layer (b), which mainly consists of a resin other than thermoplastic urethane resin, is preferably 3 μm or more, more preferably 5 μm or more, and even more preferably 7 μm or more. Furthermore, the thickness of layer (b), which mainly consists of a resin other than thermoplastic urethane resin, is preferably 500 μm or less, more preferably 450 μm or less, even more preferably 400 μm or less, even more preferably 350 μm or less, and particularly preferably 300 μm or less. By setting the thickness of layer (b) to be above the lower limit, film formation stability and abrasion resistance can be more effectively improved. On the other hand, by setting the thickness of layer (b) to be below the upper limit, tensile elongation at break and impact resistance can be more effectively improved.

[0019] The ratio (a / b) of the total thickness of layer (a) to the total thickness of layer (b) is preferably 0.7 or more, more preferably 1 or more, still more preferably 1.2 or more, and particularly preferably 1.5 or more. Also, the ratio (a / b) of the total thickness of layer (a) to the total thickness of layer (b) is preferably less than 19, more preferably 15 or less, still more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. By setting the ratio (a / b) of the total thickness of layer (a) to the total thickness of layer (b) to be at least the above lower limit value, the tensile elongation at break and impact resistance can be more effectively increased. Also, by setting the ratio (a / b) of the total thickness of layer (a) to the total thickness of layer (b) to be at most the above upper limit value, the film-forming stability and transparency can be more effectively increased.

[0020] In addition to layer (a) mainly composed of a thermoplastic urethane resin, the coextruded multilayer film of the present embodiment has layer (b) mainly composed of at least one selected from a polyester resin and a polycarbonate resin, so it has a high tensile storage modulus and excellent handling properties. Also, a film with a high tensile storage modulus is less likely to stick to the rolls used in the manufacturing process, and as a result, the production efficiency can be increased, and further, winding around roll products, processing and molding, etc. become easier. In addition, the coextruded multilayer film of the present embodiment can exhibit good interlayer adhesion by combining layer (a) having a thermoplastic urethane resin and layer (b) mainly composed of at least one selected from a polyester resin and a polycarbonate resin.

[0021] Furthermore, in the co-extruded multilayer film of this embodiment, the tensile properties of the co-extruded multilayer film can be improved by setting the total thickness of layer (a) and the total thickness of layer (b), as well as the ratio of the total thickness of layer (a) and the total thickness of layer (b) (a / b), to a predetermined range. Specifically, the tensile elongation at break in at least one direction at 23°C of the co-extruded multilayer film of this embodiment is preferably 150% or more, more preferably 200% or more, even more preferably 250% or more, and particularly preferably 300% or more. The upper limit of the tensile elongation at break in at least one direction at 23°C of the co-extruded multilayer film of this embodiment is not particularly limited, but the tensile elongation at break is preferably 1000% or less, more preferably 800% or less, even more preferably 600% or less, and particularly preferably 450% or less. More specifically, it is preferable that the tensile elongation at break of the co-extruded multilayer film in the mechanical flow direction (MD) and / or width direction (TD) is within the above range, and it is even more preferable that the tensile elongation at break of the co-extruded multilayer film in the mechanical flow direction (MD) and width direction (TD) is within the above range. When measuring the tensile elongation at break of the co-extruded multilayer film at 23°C, a tensile test is performed under the condition of a tensile speed of 200 mm / min, and the length stretched before the test piece breaks is measured.

[0022] Furthermore, the puncture elongation of the co-extruded multilayer film of this embodiment in at least one direction at 23°C is preferably 15 mm or more, more preferably 16 mm or more, even more preferably 17 mm or more, and particularly preferably 18 mm or more. The upper limit of the puncture elongation of the co-extruded multilayer film of this embodiment in at least one direction at 23°C is not particularly limited, but the puncture elongation is preferably 100 mm or less, more preferably 80 mm or less, even more preferably 70 mm or less, and particularly preferably 60 mm or less. More specifically, the puncture elongation of the co-extruded multilayer film in the machine flow direction (MD) and / or width direction (TD) is preferably within the above range, and it is more preferable that the puncture elongation of the co-extruded multilayer film in the machine flow direction (MD) and width direction (TD) is within the above range. Note that the puncture elongation of the co-extruded multilayer film at 23°C can be measured in accordance with JIS K7211-2 (2006). Specifically, at a room temperature of 23°C, a hemispherical striker is struck and penetrated through a fixed co-extruded multilayer film surface at a speed of 3.0 m / sec, and the amount of displacement at the time of penetration, that is, the depth to which the striker pushed the co-extruded multilayer film just before penetration, is measured.

[0023] In the co-extruded multilayer film of this embodiment, the impact resistance of the co-extruded multilayer film can be effectively enhanced by setting the total thickness of layer (a) to the total thickness of layer (b), and the ratio of the total thickness of layer (a) to the total thickness of layer (b) (a / b) to a predetermined range. Specifically, the puncture impact strength of the co-extruded multilayer film of this embodiment at 23°C is preferably 3.0 J or more, more preferably 3.5 J or more, and even more preferably 4.0 J or more. The upper limit of the puncture impact strength of the co-extruded multilayer film of this embodiment at 23°C is not particularly limited, but the puncture impact strength is preferably 20.0 J or less, more preferably 15.0 J or less, even more preferably 12.0 J or less, and particularly preferably 10.0 J or less. The puncture impact strength of the co-extruded multilayer film at 23°C can be measured in accordance with JIS K7211-2 (2006). Specifically, at a room temperature of 23°C, a hemispherical striker is struck and penetrated through a fixed co-extruded multilayer film surface at a speed of 3.0 m / sec, and the load at the time of impact and penetration is measured.

[0024] The tensile elongation at 120°C of the co-extruded multilayer film is preferably 50% or more, more preferably 100% or more, even more preferably 150% or more, even more preferably 200% or more, even more preferably 300% or more, and particularly preferably 400% or more. Furthermore, the tensile elongation at 120°C of the co-extruded multilayer film is preferably 1000% or less, more preferably 900% or less, and even more preferably 800% or less. If the tensile elongation at 120°C of the co-extruded multilayer film is above the above lower limit, the elongation during processing can be increased when the co-extruded multilayer film is used as a decorative film.

[0025] The yield stress of the co-extruded multilayer film at 120°C is preferably 0.2 MPa or higher, more preferably 0.3 MPa or higher, and even more preferably 0.4 MPa or higher. Furthermore, the yield stress of the co-extruded multilayer film at 120°C is preferably 10.0 MPa or lower, more preferably 8.0 MPa or lower, and even more preferably 6.0 MPa or lower. If the yield stress of the co-extruded multilayer film at 120°C is above the above lower limit, the elongation during processing can be increased when the co-extruded multilayer film is used as a decorative film. When measuring the yield stress at 120°C, a tensile test is performed under the condition of a tensile speed of 200 mm / min, and the point at which the load does not increase or temporarily decreases is defined as the "yield point," and the load at the yield point is measured. The yield stress is then calculated by dividing the load at the yield point by the initial cross-sectional area of ​​the test piece.

[0026] The thickness of the co-extruded multilayer film is preferably 33 μm or more, more preferably 35 μm or more, and even more preferably 40 μm or more. Furthermore, the thickness of the co-extruded multilayer film is preferably 1300 μm or less, more preferably 1000 μm or less, even more preferably 800 μm or less, even more preferably 700 μm or less, even more preferably 600 μm or less, and particularly preferably 500 μm or less. In this embodiment, by setting the thickness of the co-extruded multilayer film within the above range, it becomes easy to set the tensile storage modulus within the desired range, and as a result, handling performance can be more effectively improved. In addition, by setting the thickness of the co-extruded multilayer film within the above range, tensile elongation at break and impact resistance can be more effectively improved.

[0027] The yellowness (YI) of the co-extruded multilayer film is preferably 20 or less, more preferably 18 or less, even more preferably 15 or less, and particularly preferably 12 or less. The yellowness (YI) of the co-extruded multilayer film is a value measured using a spectrophotometer (SE2000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7105 (1981).

[0028] In this specification, the co-extruded multilayer film is a multilayer-structured film formed by simultaneously extruding and molding the resin constituting layer (a) and the resin constituting layer (b) by a co-extrusion method. In the co-extruded multilayer film of this embodiment, there is no adhesive layer of a solvent type or a water-dispersion type between layer (a) and layer (b), and each layer is directly fused. As a result, in the co-extruded multilayer film of this embodiment, delamination between layers hardly occurs, and the interface is homogeneous and exhibits high mechanical strength as compared with a laminate structure using an adhesive. Furthermore, since layer (a) and layer (b) are simultaneously molded in the same process, the stretching and cooling conditions are common, the orientation states of the molecular chains are approximated, and the orientation coefficients are also substantially the same.

[0029] The melt viscosity of the co-extruded multilayer film of this embodiment at 200°C and a shear rate of 1.0×10 ２ / sec is preferably 0.05×10 ３ Pa·s or more, more preferably 0.06×10 ３ Pa·s or more, and even more preferably 0.07×10 ３ Pa·s or more. Also, the melt viscosity of the co-extruded multilayer film at 200°C and a shear rate of 1.0×10 ２ / sec is preferably 1.00×10 [[ID=1​​​​​​​​​​​​​２ By keeping the melt viscosity at / sec within the above range, the fluidity of the molten resin constituting layer (a) and layer (b) can be appropriately increased, thereby enabling the formation of a multilayer film by co-extrusion. Furthermore, the co-extruded multilayer film at 200°C and a shear rate of 1.0 × 10⁻⁶ ２ By setting the melt viscosity at / sec within the above range, it is possible to manufacture a co-extruded multilayer film with excellent interlayer adhesion.

[0030] (Layer (a) mainly composed of thermoplastic polyurethane resin) Layer (a) is a layer mainly composed of thermoplastic polyurethane resin. The thermoplastic polyurethane resin is a thermoplastic polyurethane resin elastomer having structural units derived from isocyanate compound (I), structural units derived from aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from the hydroxyl value and having only hydroxyl groups as functional groups, and structural units derived from polyol (III) having a number average molecular weight of 300 or more and 10,000 or less as determined from the hydroxyl groups, wherein the isocyanate compound (I) preferably contains a total of 90 mol% or more of aliphatic isocyanate compounds containing two isocyanate groups and alicyclic isocyanate compounds containing two isocyanate groups.

[0031] In accordance with JIS K7210-1 Method A (2014), a high-efficiency flow tester (Shimadzu Corporation, "CFT-500D") was used with a temperature of 200°C, a preheating time of 5 minutes, and a shear rate of 1.0 × 10⁻⁶. ２ The melt viscosity of layer (a), measured under / sec conditions, is 0.05 × 10⁻⁶. ３ It is preferable that the concentration be Pa·s or higher, and 0.06 × 10 ３ It is more preferable that the concentration be Pa·s or higher, and 0.07 × 10 ３ It is even more preferable that the viscosity is Pa·s or higher. Also, the melt viscosity of layer (a) is 1.00 × 10⁻⁶. ４ It is preferable that it be Pa·s or less, and 9.50 × 10 ３ It is more preferable that it be Pa·s or less, and 9.00 × 10 ３ It is even more preferable that the value is Pa·s or less.

[0032] <Isocyanate Compound (I)> The isocyanate compound (I) used as a raw material for the manufacture of thermoplastic polyurethane resin elastomer contains a total of 90 mol% or more of aliphatic isocyanate compounds containing two isocyanate groups and alicyclic isocyanate compounds containing two isocyanate groups. In particular, as isocyanate compound (I), a content of alicyclic isocyanate compounds containing two isocyanate groups of 80 mol% or more is preferred from the viewpoint of improving the transparency and abrasion resistance of the resulting thermoplastic polyurethane resin elastomer. Alicyclic isocyanate compounds have a greater effect in increasing the amorphousness of thermoplastic polyurethane resin elastomer than linear aliphatic isocyanates, resulting in better transparency. By keeping the content of the main component isocyanate compound within the above range, the various physical properties of the resulting co-extruded multilayer film, such as mechanical properties and chemical resistance, can be improved.

[0033] Examples of aliphatic isocyanate compounds and alicyclic isocyanate compounds include various known aliphatic polyisocyanate compounds and alicyclic polyisocyanate compounds.

[0034] Examples of isocyanate compounds (I) include aliphatic diisocyanate compounds such as tetramethylene diisocyanate, 1,5-pentane diisocyanate, hexamethylene diisocyanate, 1,7-heptamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and dimer diisocyanate obtained by converting the carboxyl group of a dimer acid to an isocyanate group; Examples include alicyclic diisocyanate compounds such as 4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI), and 1,3-bis(isocyanatomethyl)cyclohexane (1,3-H6XDI). These may be used individually or in combination of two or more. When used in combination, it is preferable that the compound mainly contains an isocyanate compound containing two isocyanate groups in an amount of preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 98 mol% or more.

[0035] Among these, 1,6-hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI), and 1,3-bis(isocyanatomethyl)cyclohexane (1,3-H6XDI) are preferred as isocyanate compound (I) in terms of the mechanical properties, durability, and industrial availability at low cost. 4,4'-dicyclohexylmethane diisocyanate (H12MDI) and 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) are more preferred because they provide good transparency. By using such isocyanate compounds, the various physical properties of the resulting thermoplastic polyurethane resin elastomer, such as weather resistance, light resistance, transparency, abrasion resistance, and chemical resistance, are improved in a well-balanced manner. Furthermore, from the standpoint of environmentally friendly biomass resources, 1,5-pentanediisocyanate and 1,7-heptamethylenediisocyanate are preferred biomass resources.

[0036] As the isocyanate compound (I), an isocyanate compound containing one isocyanate group can also be used in combination, provided that the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. When using an isocyanate compound containing one isocyanate group in combination, its proportion is preferably 5 mol% or less, more preferably 3 mol% or less, and even more preferably 1 mol% or less in the total isocyanate compound (I). By keeping the content of the isocyanate compound containing one isocyanate group within the above range, it is possible to suppress a decrease in the molecular weight of the resulting thermoplastic polyurethane resin elastomer and improve durability such as chemical resistance.

[0037] As the isocyanate compound (I), an isocyanate compound containing 2.1 or more isocyanate groups as an average functional group can also be used in combination, provided that the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. Furthermore, when using an isocyanate compound containing 3 or more isocyanate groups as an average functional group, its proportion is preferably 3 mol% or less, more preferably 1 mol% or less, and even more preferably 0.5 mol% or less in the total isocyanate compound (I). By keeping the content of the isocyanate compound containing 3 or more isocyanate groups as an average functional group within the above range, the moldability of the thermoplastic polyurethane resin elastomer obtained by crosslinking can be improved and gelation can be suppressed.

[0038] As the isocyanate compound (I), an isocyanate compound having an aromatic ring can also be used in combination, provided that the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. When an isocyanate compound having an aromatic ring is used in combination, its proportion is preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 1 mol% or less in the total isocyanate compound (I). By keeping the content of the isocyanate compound having an aromatic ring within the above range, the weather resistance and durability of the resulting thermoplastic polyurethane resin elastomer can be improved.

[0039] <Aliphatic alcohol (II) having a number average molecular weight of less than 300, determined from its hydroxyl value, and having only hydroxyl groups as functional groups> The aliphatic alcohol (II) used as a raw material for the manufacture of thermoplastic polyurethane resin elastomers is an aliphatic alcohol having a number average molecular weight of less than 300, determined from its hydroxyl value, and having only hydroxyl groups as functional groups. The aliphatic alcohol (II) preferably contains 90 mol% or more of aliphatic diols having 12 or fewer carbon atoms, more preferably 10 or fewer carbon atoms. Furthermore, the aliphatic alcohol (II) is preferably a low molecular weight compound polyol having at least two active hydrogen atoms that act as a chain extender and react with isocyanate groups. In this specification, "aliphatic alcohol (II) having only hydroxyl groups as functional groups" may be referred to as "chain extender (II)".

[0040] As an aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from its hydroxyl value and having only a hydroxyl group as its functional group, various known aliphatic alcohols having only a hydroxyl group as their functional group can be used. Specific examples of aliphatic alcohols (II) having a number average molecular weight of less than 300 as determined from its hydroxyl value and having only a hydroxyl group as its functional group include linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, and 2,4-heptanediol. Examples include branched diols such as 1,4-dimethylolhexane, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, and dimergol; diols having an ether group such as diethylene glycol and propylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and 1,4-dihydroxyethylcyclohexane; and polyols such as glycerin, trimethylolpropane, and pentaerythritol. These aliphatic alcohols may be used individually or in combination of two or more. When used in combination, it is preferable that the total amount of these aliphatic alcohols, including the preferred diols listed below, be preferably 70 mol% or more, more preferably 90 mol% or more, and most preferably 98 mol% or more in the aliphatic alcohol (II).

[0041] Among the above aliphatic alcohols (II), linear aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are preferred, and among these, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are more preferred. Among these linear diols, 1,4-butanediol is even more preferred in terms of the balance of physical properties. Furthermore, from the viewpoint of environmentally friendly biomass resource-derived materials, biomass resource-derived 1,3-propanediol and 1,4-butanediol are even more preferred, and in terms of the balance of physical properties, biomass resource-derived 1,4-butanediol is the most preferred. By using the above aliphatic alcohols (II), the phase separation between the soft segment and hard segment of the thermoplastic polyurethane resin elastomer obtained can be improved, and durability such as chemical resistance can be enhanced.

[0042] The aliphatic alcohol (II) preferably contains 90 mol% or more of the linear aliphatic diols described above. By using a predetermined amount or more of linear aliphatic diols as the aliphatic alcohol (II), the cohesive force of the hard segments of the resulting thermoplastic polyurethane resin elastomer can be increased, and various physical properties such as mechanical properties of the resulting thermoplastic polyurethane resin elastomer can be improved.

[0043] As the aliphatic alcohol(II), an aliphatic monoalcohol compound containing one hydroxyl group can also be used in combination, provided that the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. When an aliphatic monoalcohol compound containing one hydroxyl group is used in combination, its proportion is preferably 5 mol% or less, more preferably 3 mol% or less, and even more preferably 1 mol% or less, relative to the aliphatic alcohol(II). By keeping the content of the aliphatic monoalcohol compound containing one hydroxyl group within the above range, it is possible to suppress a decrease in the molecular weight of the resulting thermoplastic polyurethane resin elastomer and improve durability such as chemical resistance.

[0044] As the aliphatic alcohol(II), aliphatic polyhydric alcohol compounds such as glycerin, trimethylolpropane, and pentaerythritol containing three or more hydroxyl groups can also be used in combination, provided that the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. When using an aliphatic alcohol compound containing three or more hydroxyl groups in combination, its proportion is preferably 3 mol% or less, more preferably 1 mol% or less, and even more preferably 0.5 mol% or less, relative to the aliphatic alcohol(II). By keeping the content of the aliphatic alcohol containing three or more hydroxyl groups within the above range, the moldability of the thermoplastic polyurethane resin elastomer obtained by crosslinking can be improved and gelation can be suppressed.

[0045] Furthermore, aliphatic alcohol(II) can also be alcohols having aromatic groups, or active hydrogen compounds other than hydroxyl groups, such as amino groups or carboxyl groups, as long as the physical properties of the resulting thermoplastic polyurethane resin elastomer do not change significantly. When these are used in combination, their proportion is preferably 5 mol% or less, more preferably 3 mol% or less, and even more preferably 1 mol% or less, relative to the aliphatic alcohol(II). By keeping the content of these compounds other than aliphatic alcohol(II) within the above range, it is possible to suppress a decrease in the weather resistance, color, and durability against hydrolysis of the resulting thermoplastic polyurethane resin elastomer.

[0046] <Polyol (III) with a number average molecular weight of 300 or more and 10,000 or less determined from the hydroxyl value> (Polycarbonate diol (IIIA)) The polyol (III) used as a raw material for the production of thermoplastic polyurethane resin elastomers is preferably a polyol with a number average molecular weight of 300 or more and 10,000 or less determined from the hydroxyl value, and more preferably a polyol with a number average molecular weight of 500 or more and 5,000 or less. The polyol (III) is preferably a homopolymerized (homo) or copolymerized polycarbonate diol (IIIA) containing a total of 80 mol% or more of structural units (A) derived from the transesterification reaction product of a hydrocarbon diol having 3 to 5 carbon atoms and a carbonate ester, and / or structural units (B) derived from the transesterification reaction product of a hydrocarbon diol having 6 to 20 carbon atoms and a carbonate ester. The content ratio of structural units (A) to structural units (B) may be in the range of 100:0 to 0:100 in molar ratio. Because polycarbonate diols have a polar group called a carbonate bond, they have high affinity with resins that also have polar groups, such as polyester resins and polycarbonate resins, resulting in excellent interlayer adhesion when formed into laminated films. Furthermore, polycarbonate diols have excellent durability and are particularly suitable for use in thin film applications.

[0047] The polyol (III) is preferably a copolymerized polycarbonate diol, in which case the molar ratio of structural unit (A) to structural unit (B) is preferably 95:5 to 5:95. Using such a copolymerized polycarbonate diol is preferable because it lowers the melting point of the thermoplastic polyurethane resin elastomer, improving moldability and increasing transparency. Furthermore, using a copolymerized polycarbonate diol makes it easier to control crystallinity, suppressing clouding of the thermoplastic polyurethane resin elastomer, and controlling crystallinity also improves interlayer adhesion when forming laminated films with other resins.

[0048] The polycarbonate diol (IIIA) preferably contains 80 mol% or more of a polycarbonate diol comprising repeating structural units represented by the following formula (A) and / or repeating structural units represented by the following formula (B). In this specification, the repeating structural unit represented by the following formula (A) is also referred to as "repeat unit (A)," and the repeating structural unit represented by the following formula (B) is also referred to as "repeat unit (B)." The number average molecular weight of the polycarbonate diol (IIIA), determined from its hydroxyl value, is preferably 300 to 10,000, more preferably 500 to 5,000, and even more preferably 700 to 4,000.

[0049]

[0050] The repeating structural unit represented by formula (A) above represents a structural unit derived from the transesterification reaction product of a hydrocarbon diol having 3 to 5 carbon atoms and a carbonate ester. The repeating structural unit represented by formula (B) above represents a structural unit derived from the transesterification reaction product of a hydrocarbon diol having 6 to 20 carbon atoms and a carbonate ester. In formula (A), R １ R is a hydrocarbon group having 3 to 5 carbon atoms, in formula (B), ２ This refers to a hydrocarbon group with 6 to 20 carbon atoms.

[0051] A thermoplastic polyurethane resin elastomer is produced using a specific polycarbonate diol (IIIA) having repeating units (A) and repeating units (B) as a raw material for manufacturing thermoplastic polyurethane resin elastomers. This thermoplastic polyurethane resin elastomer, composed of this polycarbonate diol (IIIA), a specific isocyanate compound (I), and a specific chain extender (II), has special properties that make it easy to control the elastic modulus with temperature required for various film applications and to control appropriate tensile strength. At the same time, it is suitable for obtaining film or sheet-like thermoplastic polyurethane resin elastomer molded products with excellent durability such as weather resistance and chemical resistance, as well as transparency and texture.

[0052] R in equation (A) １The repeating unit (A) is a hydrocarbon group having 3 to 5 carbon atoms, and by using a hydrocarbon diol having 3 to 5 carbon atoms as a raw material diol for polycarbonate diol (IIIA), a hydrocarbon group having 3 to 5 carbon atoms can be introduced into polycarbonate diol (IIIA).

[0053] R in equation (A) １ It is preferable that the repeating unit (A) is a linear hydrocarbon group, and that it is preferable that the repeating unit (A) is derived from linear 1,3-propanediol, 1,4-butanediol, or 1,5-pentanediol, from the viewpoint of industrial availability and the superior physical properties of films and molded products using the resulting thermoplastic polyurethane resin elastomer. Furthermore, in applications where chemical resistance is more important among the physical properties of the thermoplastic polyurethane resin elastomer, it is particularly preferable to use 1,3-propanediol or 1,4-butanediol, and it is most preferable to use 1,4-butanediol, which also possesses high mechanical properties. In addition, from the viewpoint of environmentally friendly biomass resource-derived materials, biomass resource-derived 1,3-propanediol or 1,4-butanediol is preferred.

[0054] R in equation (B) ２ The carbon number of is 6 to 20, preferably 8 to 12, and particularly preferably 10. The repeating unit (B) is a hydrocarbon diol having 6 to 20, preferably 8 to 12, and particularly preferably 10 carbon atoms, which can be used as a raw material diol for polycarbonate diol (IIIA). This allows for the introduction of a hydrocarbon group with a predetermined number of carbon atoms into polycarbonate diol (IIIA).

[0055] The repeating unit (B) is preferably derived from linear 1,12-dodecanediol, 1,10-decanediol, 1,9-nonanediol, 1,8-octanediol, 1,6-hexanediol, etc. Furthermore, from the viewpoint of environmentally friendly biomass resources, the raw material diol is preferably 1,9-nonanediol or 1,10-decanediol derived from biomass resources, and moreover, 1,10-decanediol is most preferred from the viewpoint of the mechanical properties and chemical resistance of the film using the resulting thermoplastic polyurethane resin elastomer, and because it is derived from non-edible plants.

[0056] Polycarbonate diol (IIIA) may contain only one type of repeating unit (A), or two or more types. Similarly, polycarbonate diol (IIIA) may contain only one type of repeating unit (B), or two or more types. Polycarbonate diol (IIIA) may also contain repeating units other than repeating units (A) and repeating unit (B) in an amount that does not impair the effects of the present invention, for example, 20 mol% or less of the total repeating units.

[0057] The molar ratio of repeating units (B) to repeating units (A) in polycarbonate diol (IIIA) (repeating unit (B) / repeating unit (A), sometimes referred to as "molar ratio (B) / (A)") is preferably 0.03 to 99, more preferably 0.05 to 19, and even more preferably 0.10 to 10. By setting the molar ratio to or above the lower limit, the transparency and flexibility of films and molded products using the resulting thermoplastic polyurethane resin elastomer can be effectively enhanced. On the other hand, by setting the molar ratio to or below the upper limit, a decrease in the mechanical strength and chemical resistance of films and molded products using the resulting thermoplastic polyurethane resin elastomer can be suppressed.

[0058] The molar ratio (B) / (A) of polycarbonate diol (IIIA) can be calculated by the following method: Polycarbonate diol (IIIA) in CDCl ３ The mixture is dissolved, and 400 MHz 1H-NMR (AL-400, manufactured by JEOL Ltd.) is measured. From the signal position of each component, the molar ratio (B) / (A) of repeating unit (A) and repeating unit (B) is calculated.

[0059] The number average molecular weight determined from the hydroxyl value of polycarbonate diol (IIIA) is preferably 300 to 10,000, more preferably 500 to 5,000, even more preferably 800 to 4,000, and particularly preferably 1,000 to 3,000. By setting the number average molecular weight determined from the hydroxyl value of polycarbonate diol (IIIA) within the above range, the mechanical properties of the resulting thermoplastic polyurethane resin elastomer can be improved. Furthermore, by setting the number average molecular weight determined from the hydroxyl value of polycarbonate diol (IIIA) above the lower limit, the hardness of the molded product obtained from the thermoplastic polyurethane resin elastomer can be appropriately controlled, and the flexibility characteristic of thermoplastic polyurethane resin elastomer can be maintained. Furthermore, by setting the number average molecular weight below the upper limit, it is possible to suppress the excessive decrease in the elastic modulus of the resulting molded product, and the elastic recovery characteristic of thermoplastic polyurethane resin elastomer can be maintained.

[0060] The number-average molecular weight (Mn) of polycarbonate diol (IIIA), determined from its hydroxyl value, is calculated using the following method. First, the hydroxyl value of the polycarbonate diol is measured using an acetylation reagent in accordance with JIS K1557-1 (2007). Then, the number-average molecular weight is calculated from the hydroxyl value using the following formula (1): Number-average molecular weight = 2 × 56.1 / (Hydroxyl value × 10) －３ ) (1)

[0061] The hydroxyl value of polycarbonate diol (IIIA) is preferably 22.4 mg-KOH / g or higher, more preferably 28.1 mg-KOH / g or higher, and even more preferably 37.4 mg-KOH / g or higher. Furthermore, the hydroxyl value of polycarbonate diol (IIIA) is preferably 224.4 mg-KOH / g or lower, more preferably 140.3 mg-KOH / g, and even more preferably 112.2 mg-KOH / g. The hydroxyl value of polycarbonate diol (IIIA) is measured by a method using an acetylation reagent in accordance with JIS K1557-1 (2007).

[0062] Polycarbonate diol (IIIA) used as a raw material for the manufacture of thermoplastic polyurethane resin elastomers may be of one type only, or two or more types with different repeating units, molar ratios, and physical properties may be used. Polycarbonate diol (IIIA) can be manufactured, for example, by the method described in WO2020 / 208507. The content of the method for manufacturing polycarbonate diol (IIIA) described in WO2020 / 208507 is incorporated by reference as constituting a part of this specification.

[0063] (Polyols other than polycarbonate diol (IIIA)) In the polyurethane formation reaction when manufacturing thermoplastic polyurethane resin elastomers, polycarbonate diol (IIIA) may be used in combination with other polyols as needed, to the extent that it does not affect the physical properties. Here, polyols other than polycarbonate diol (IIIA) are not particularly limited as long as they are used in the normal manufacture of polyurethane, and examples include polyester polyols, polycaprolactone polyols, polyalkylene ether glycols, and polycarbonate polyols other than polycarbonate diol (IIIA).

[0064] Examples of polyester polyols include those obtained by dehydration condensation of aliphatic glycols with aliphatic dibasic acids such as adipic acid or aromatic dibasic acids such as phthalic anhydride. Examples of polyalkylene polyol ether glycols include poly(oxyethylene) glycol and poly(oxypropylene) glycol obtained by addition polymerization of ethylene oxide or propylene oxide, and polytetramethylene ether glycol (PTMG) obtained by ring-opening polymerization of tetrahydrofuran. In addition, all known polyols, such as polyolefin polyols, can be used in combination. Polyols other than polycarbonate diol (IIIA) may be used alone or in combination of two or more. The content of polyols other than polycarbonate diol (IIIA) is preferably 20 mol% or less relative to 100 mol% of polyol (III).

[0065] In addition to polycarbonate diol (IIIA), it is also preferable to use polyols derived from biomass resources. Using polyols derived from biomass resources in combination is preferable because it increases the biomass content of the resulting thermoplastic polyurethane resin elastomer. Examples include polyester polyols obtained by reacting dicarboxylic acids and diols from biomass resources such as polytetramethylene ether glycol (PTMG), polytrimethylene ether glycol, biosuccinic acid, biosebacic acid, and bioitaconic acid. Among these, from the viewpoint of non-edible plant origin, those using biosebacic acid produced from castor oil are preferred.

[0066] In the production of thermoplastic polyurethane resin elastomers, the polyol (III), specifically polycarbonate diol (IIIA), is preferably at least 80 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol%, and particularly preferably at least 98 to 100 mol%. By setting the polycarbonate diol (IIIA) content within the above range, it becomes easier to control the elastic modulus with respect to temperature in film-like materials and molded articles using thermoplastic polyurethane resin elastomers, and easier to control a constant tensile strength. Furthermore, by setting the polycarbonate diol (IIIA) content within the above range, various durability properties such as weather resistance and chemical resistance, as well as transparency, can be effectively enhanced.

[0067] (Thermoplastic Polyurethane Resin Elastomer) The thermoplastic polyurethane resin elastomer is a thermoplastic polyurethane resin elastomer having structural units derived from an isocyanate compound (I), structural units derived from an aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from its hydroxyl value and having only hydroxyl groups as functional groups, and structural units derived from a polyol (III) having a number average molecular weight of 300 or more and 10,000 or less as determined from its hydroxyl value, wherein the isocyanate compound (I) contains a total of 90 mol% or more of aliphatic isocyanate compounds containing two isocyanate groups and alicyclic isocyanate compounds containing two isocyanate groups. The thermoplastic polyurethane resin elastomer is a block copolymer composed of hard segments formed by the reaction of a short-chain diol acting as a chain extender with diisocyanate and soft segments formed by the reaction of a polydiol with diisocyanate.

[0068] In this embodiment, the hydroxyl group equivalent of polyol (III) (EIII): isocyanate equivalent of isocyanate compound (I) (EI): hydroxyl group equivalent of aliphatic alcohol (II) (EII) is preferably in an equivalent ratio of 1.0:2.0 to 6.0:1.0 to 5.0. When the hydroxyl group equivalent of polyol (III) (EIII) is set to 1, the ratio of isocyanate equivalent of isocyanate compound (I) (EI) / hydroxyl group equivalent of aliphatic alcohol (II) (EII) is expressed as an integer value of 2 / 1, 3 / 2, 4 / 3, 5 / 4, 6 / 5, and includes equivalent ratios in between. Note that the hydroxyl group equivalent is the chemical formula weight per hydroxyl group in the polyol or aliphatic alcohol. Also, the isocyanate equivalent is the chemical formula weight per isocyanate group in the isocyanate compound.

[0069] When the hydroxyl group equivalent (EIII) of polyol (III) is set to 1, setting the isocyanate equivalent (EI) of isocyanate compound (I) to 2.0 or higher reduces the adhesion of the thermoplastic polyurethane resin elastomer to the roll during film molding, further improving mechanical strength, tensile strength, and elastic properties, as well as heat resistance. On the other hand, setting the isocyanate equivalent (EI) of isocyanate compound (I) to 6.0 or lower reduces the elastic modulus of the thermoplastic polyurethane resin elastomer film, suppresses a decrease in elongation at break and a decrease in elastic properties, and improves flexibility at low temperatures. When the hydroxyl group equivalent (EIII) of polyol (III) is set to 1, the isocyanate equivalent (EI) of isocyanate compound (I) is preferably 2.5 to 5.5, and more preferably 3.0 to 5.5, from the perspective of balancing film productivity, various physical properties, and various durabilitys.

[0070] When the hydroxyl group equivalent (EIII) of polyol (III) is set to 1, setting the hydroxyl group equivalent (EII) of aliphatic alcohol (II) to 1.0 or higher reduces the adhesion of the thermoplastic polyurethane resin elastomer to the roll during film molding and further increases its strength. On the other hand, setting the hydroxyl group equivalent (EII) to 5.0 or lower increases flexibility. When the hydroxyl group equivalent (EIII) of polyol (III) is set to 1, the hydroxyl group equivalent (EII) of aliphatic alcohol (II) is preferably 1.5 to 4.5, and more preferably 2.0 to 4.5, considering the balance between film productivity, strength, and flexibility.

[0071] The equivalent ratios of (EI), (EII), and (EIII) in thermoplastic polyurethane resin elastomers can usually be confirmed by measurement using an NMR (nuclear magnetic resonance spectroscopy) device with a frequency of 400 MHz or higher.

[0072] In this embodiment, it is preferable that the equivalent ratio is 0.95 ≤ (EI) / ((EII) + (EIII)) ≤ 1.05. The value of (EI) / ((EII)+(EIII)) is preferably 0.95 or higher, more preferably 0.97 or higher, and even more preferably 0.99 or higher. Furthermore, the value of (EI) / ((EII)+(EIII)) is preferably 1.05 or lower, more preferably 1.04 or lower, and even more preferably 1.03 or lower. By setting the value of (EI) / ((EII)+(EIII)) to be above the lower limit, the adhesion of the thermoplastic polyurethane resin elastomer to the roll during film molding can be reduced, and various physical properties such as chemical resistance and heat resistance can be improved. Furthermore, by setting the value of (EI) / ((EII)+(EIII)) to be below the upper limit, the formation of unintended crosslinking structures and the reaction of unreacted isocyanate groups with moisture in the air or water tank to form amino groups can be suppressed, and as a result, fisheyes in the film can be suppressed, moldability can be improved, yellowing can be suppressed, and mechanical strength can be improved.

[0073] The (EI) / ((EII)+(EIII)) value of thermoplastic polyurethane resin elastomers can be determined not only by the mass ratio of each component during polymerization, but also by measurement using an NMR (nuclear magnetic resonance spectroscopy) device with a frequency of 400 MHz or higher.

[0074] Thermoplastic polyurethane resin elastomers preferably contain 10% by mass or more of structural units derived from biomass resources, more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more. By increasing the content of structural units derived from biomass resources, it is possible to obtain an effect that contributes to mitigating global warming and is environmentally conscious.

[0075] As used herein, biomass resources include materials obtained by the photosynthesis of plants, which convert sunlight energy into starch, sugar, and cellulose, as well as the bodies of animals that feed on plants and grow, and products made by processing plant or animal bodies. Among these, plant resources are the most preferred biomass resources. Examples of plant resources include wood, rice straw, rice husks, rice bran, old rice, corn, sugarcane, cassava, sago palm, okara, corn cob, tapioca residue, bagasse, vegetable oil residue, potatoes, buckwheat, soybeans, oils and fats, waste paper, papermaking residue, fishery residue, livestock excrement, sewage sludge, and food waste. Among these, plant resources such as wood, rice straw, rice hulls, rice bran, old rice, corn, sugarcane, cassava, sago palm, okara, corn cob, tapioca residue, bagasse, vegetable oil cake, potato, buckwheat, soybean, oils and fats, waste paper and papermaking residue are preferred, more preferably wood, rice straw, rice hulls, old rice, corn, sugarcane, cassava, sago palm, potato, oils and fats, waste paper and papermaking residue, and most preferably corn, sugarcane, cassava and sago palm.

[0076] These biomass resources are converted into carbon sources through known pretreatment and saccharification processes, such as chemical treatment with acids and alkalis, biological treatment using microorganisms, and physical treatment, although these processes are not particularly limited. These processes typically include pretreatment steps such as chipping, grinding, and crushing of the biomass resources. If necessary, further grinding steps using a grinder or mill are included.

[0077] The biomass resources thus refined are further processed into a carbon source through pretreatment and saccharification. Specific methods include chemical methods such as acid treatment with strong acids like sulfuric acid, nitric acid, hydrochloric acid, or phosphoric acid, alkaline treatment, ammonia freeze-steam explosion, solvent extraction, supercritical fluid treatment, and oxidizing agent treatment; physical methods such as fine grinding, steam explosion, microwave treatment, and electron beam irradiation; and biological treatments such as hydrolysis by microorganisms or enzymes.

[0078] Examples of carbon sources derived from biomass resources include hexoses such as glucose, mannose, galactose, fructose, sorbose, and tagatose; pentoses such as arabinose, xylose, ribose, xylulose, and ribulose; disaccharides or polysaccharides such as pentosan, saccharose, starch, and cellulose; fatty acids such as butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, monotic acid, arachidic acid, eicosenoic acid, arachidonic acid, behenic acid, erucic acid, docosapentaenoic acid, docosahexaenoic acid, lignoceric acid, and seracolenic acid; and fermentable carbohydrates such as polyalcohols such as glycerin, mannitol, xylitol, and ribitol. Among these, glucose, maltose, fructose, sucrose, lactose, trehalose, and cellulose are preferred.

[0079] Among the various biomass resources, thermoplastic polyurethane resin elastomers using biomass resources derived from non-edible plants are most preferred because they do not compete with humanity's food supply problems and also from the perspective of animal welfare. The content of non-edible plant-derived materials in the raw material diol of the raw material polyol for thermoplastic polyurethane resin elastomers is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 50% by mass or more. Examples of biomass resources derived from non-edible plants include non-edible grasses, trees, oil palm pomace and empty fruit clusters, castor beans, corn cobs and stems and leaves, bagasse, soybean and rapeseed pomace and empty pods, food processing residues, or extracts from such biomass (vegetable oils such as castor oil, cellulose, glucose, etc.). Examples of diols derived from non-edible plants include 1,10-decanediol derived from castor oil, 1,3-propanediol and 1,4-butanediol derived from corn cobs and stems and leaves, etc. However, in recent years, since corn cultivation requires a large amount of water, castor oil derived from castor beans, which require only a small amount of water during cultivation, is preferable to non-edible castor oil derived from corn, from the perspective of addressing humanity's water shortage problem.

[0080] To obtain a thermoplastic polyurethane resin elastomer with a biomass resource content of 10% by mass or more, the biomass resource component may be used in any of the polyol (III), isocyanate compound (I), or aliphatic alcohol (II), but it is preferable to use the biomass resource component in the raw material diol of polyol (III). Since polyol (III) has the highest mass composition ratio in thermoplastic polyurethane resin elastomers, the biomass resource content can be increased. The content of non-edible plant-derived materials in the raw material diol of polyol (III) is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more.

[0081] Furthermore, the following methods can be used to increase the biomass resource content in the raw materials for the manufacture of thermoplastic polyurethane resin elastomers: 1) Use 1,5-pentamethylene diisocyanate derived from biomass resources as the isocyanate compound (I). 2) Use ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,10-decanediol derived from biomass resources as the aliphatic alcohol (II). 3) Use a polycarbonate diol (IIIA) that uses ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,10-decanediol derived from biomass resources as copolymer components.

[0082] To obtain a non-yellowing thermoplastic polyurethane film and co-extruded multilayer film using a thermoplastic polyurethane resin elastomer that has special properties such as easy control of the elastic modulus value with temperature and appropriate control of tensile strength, as well as various durability such as weather resistance and chemical resistance, and excellent transparency and texture, it is particularly preferable to use 1,10-decanediol produced from castor oil derived from non-edible plants.

[0083] Furthermore, as mentioned above, when using polyol (III) in combination with polycarbonate diol (IIIA) and other polyols, it is preferable to use polyols derived from biomass resources as the polyols used in combination, as this increases the biomass content of the thermoplastic polyurethane resin elastomer.

[0084] As a method for increasing the biomass content of thermoplastic polyurethane resin elastomers, it is preferable to set the content of non-edible plant-derived diols in the raw material diol of polyol (III), particularly polycarbonate diol (IIIA), to 10 mol% or more. 1,10-decanediol, which is particularly preferred as a non-edible plant-derived diol for biomass resources, is preferably used as a component of polycarbonate diol (IIIA). The content of non-edible plant-derived diols in the raw material diol of polyol (III), particularly polycarbonate diol (IIIA), is more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and particularly preferably 50 mol% or more.

[0085] The molecular weight of the thermoplastic polyurethane resin elastomer is adjusted as appropriate according to the application of the co-extruded multilayer film to be manufactured, and there are no particular restrictions. However, it is preferably 50,000 to 500,000, and more preferably 100,000 to 300,000, as measured by gel permeation chromatography (GPC) in terms of polystyrene weight-average molecular weight (Mw). Setting the weight-average molecular weight (Mw) above the lower limit makes it easier to obtain sufficient strength, hardness, and durability. Conversely, setting the weight-average molecular weight (Mw) below the upper limit makes it easier to improve handling properties such as moldability and processability.

[0086] The molecular weight distribution (Mw / Mn) of the thermoplastic polyurethane resin elastomer is preferably 1.5 to 3.5, more preferably 1.7 to 3.0, and even more preferably 1.8 to 2.5. Setting the molecular weight distribution below the upper limit makes it easier to improve moldability. Furthermore, setting the molecular weight distribution above the lower limit improves purification efficiency. The molecular weight distribution of the thermoplastic polyurethane resin elastomer can be measured by GPC.

[0087] The tensile storage modulus of thermoplastic polyurethane resin elastomer, as determined by a tensile test at room temperature, is preferably 50 MPa to 400 MPa, and more preferably 55 MPa to 380 MPa. When used in applications such as films and sheets, a tensile storage modulus of 60 MPa to 360 MPa is particularly preferred. By setting the tensile storage modulus above the lower limit, the mechanical strength can be increased. Conversely, by setting the tensile storage modulus below the upper limit, the mechanical strength, elongation at break, and elastic properties can be improved. The tensile storage modulus can be measured in accordance with JIS K6301 (2010).

[0088] The durometer hardness of thermoplastic polyurethane resin elastomer is preferably Shore A70 to Shore D80, and more preferably Shore A75 to Shore D65. For applications such as films and sheets, Shore A80 to Shore D65 is particularly preferred. When flexibility is particularly required, Shore A80 to Shore A95 is particularly preferred. Setting the Shore hardness to Shore A70 or higher facilitates cutting and molding and improves demolding during molding. Furthermore, setting the Shore hardness to Shore D80 or lower improves elastic properties. Shore hardness can be measured with a hardness tester.

[0089] The melt viscosity of thermoplastic polyurethane resin elastomer is preferably 0.05 to 150 g / 10 min, and more preferably 0.1 to 100 g / min, when the melt mass flow rate (MFR) is measured at a load of 2.16 kg using a melt mass flow rate measuring device (manufactured by Tateyama Kagaku Kogyo, device name: Melt Indexer) in accordance with JIS K 7210-1 A method (2014) (ISO 1133) at a normal molding temperature of 150°C to 220°C. By keeping the melt viscosity within the above range, fluidity can be increased and moldability can be improved.

[0090] The yellowness index (YI) of the thermoplastic polyurethane resin elastomer is preferably 10 or less, more preferably 5 or less, and most preferably 3 or less. By keeping the yellowness index (YI) below the above upper limit, yellowing becomes less noticeable even in thin films and sheets. YI can be measured by the method described in JIS K7373 (2006).

[0091] The transparency of films and the like made using thermoplastic polyurethane resin elastomers can usually be measured by a haze meter or visual inspection. Films made using thermoplastic polyurethane resin elastomers have excellent transparency. Thermoplastic polyurethane resin elastomers can be manufactured, for example, by the method described in WO 2020 / 208507. The provisions relating to the method for manufacturing thermoplastic polyurethane resin elastomers described in WO 2020 / 208507 are incorporated herein by reference as constituting a part of this specification.

[0092] (Additives) The thermoplastic polyurethane resin elastomer may contain one or more additives selected from the group consisting of hindered phenol antioxidants, ultraviolet absorbers, light stabilizers (HALS), and lubricants as stabilizers. These additives are preferred because the compounded composition improves the stability of the resin. The thermoplastic polyurethane resin elastomer may also contain internal release agents, external release agents, fillers, plasticizers, colorants (dyes, pigments), flame retardants, crosslinking agents, reaction accelerators, reinforcing agents, etc., depending on the application.

[0093] Examples of internal mold release agents include fatty acid amides, fatty acid esters, fatty acids, fatty acid salts, and silicone oil. Examples of fatty acid amides include caproic acid amide, lauric acid amide, myristic acid amide, stearic acid amide, oleic acid amide, ethylenebisstearate amide, and ethylenebisoleic acid amide. Examples of fatty acid esters include esters of long-chain fatty acids and alcohols, specifically sorbitan monolaurate, butyl stearate, butyl laurate, octyl palmitate, and stearyl stearate. Examples of fatty acids include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, montanic acid, lindeic acid, oleic acid, erucic acid, and linoleic acid. Examples of fatty acid salts include metal (e.g., barium, zinc, magnesium, calcium, etc.) salts of fatty acids.

[0094] Examples of fillers include talc, calcium carbonate, chalk, calcium sulfate, clay, kaolin, silica, glass, fumed silica, mica, wollastonite, feldspar, aluminum silicate, calcium silicate, alumina, alumina trihydrate and other alumina hydrates, glass microspheres, ceramic microspheres, thermoplastic resin microspheres, barite, wood powder, glass fiber, carbon fiber, marble dust, cement dust, magnesium oxide, magnesium hydroxide, antimony oxide, zinc oxide, barium sulfate, titanium dioxide, titanates, and combinations thereof. Preferably, the filler is talc, calcium carbonate, barium sulfate, silica, glass, glass fiber, alumina, titanium dioxide, or a combination thereof, and more preferably talc, calcium carbonate, barium sulfate, glass fiber, or a combination thereof. As fillers, those listed in Zweifel Hans et al.'s "Plastics Additives Handbook," Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 17, pp. 901–948 (2001) can be used.

[0095] Examples of plasticizers include mineral oil, abietic acid esters, adipic acid esters, alkyl sulfonic acid esters, azelaic acid esters, benzoic acid esters, chlorinated paraffin, citrate esters, epoxides, glycol ethers and their esters, glutaric acid esters, hydrocarbon oils, isobutyric acid esters, oleic acid esters, pentaerythritol derivatives, phosphate esters, phthalic acid esters, polybutene, ricinoleic acid esters, sebaciate esters, sulfonamides, trimellitic acid esters, pyromellitic acid esters, biphenyl derivatives, stearic acid esters, difrangic acid esters, fluorine-containing plasticizers, hydroxybenzoic acid esters, isocyanate ester adducts, polycyclic aromatic compounds, natural product derivatives, siloxane-based plasticizers, tar-based products, thioesters, thioethers, and combinations thereof. As plasticizers, those listed in George Wypych's paper "Handbook of Plasticizers" (ChemTec Publishing, Toronto-Scarborough, Ontario, 2004) can be used.

[0096] Examples of colorants (dyes, pigments) include inorganic pigments such as metal oxides (e.g., iron oxide, zinc oxide, titanium dioxide), mixed metal oxides, carbon black, and combinations thereof; organic pigments such as anthraquinone, antantrone, azo compounds, monoazo compounds, arylamides, benzimidazolone, bona lake, diketopyrrolopyrrole, dioxazine, disazo compounds, diarylide compounds, flavanthrone, indanthrone, isoindolinone, isoindoline, monoazo salts, naphthol, β-naphthol, naphthol AS, naphthol lake, perylene, perinone, phthalocyanine, pyrantrone, quinacridone, quinophthalone, and combinations thereof; and combinations of inorganic and organic pigments. As colorants, those listed in Zweifel Hans et al.'s "Plastics Additives Handbook," Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 15, pp. 813–882 (2001) can be used.

[0097] Examples of antioxidants include aromatic amines or hindered amines such as alkyldiphenylamine, phenyl-α-naphthylamine, alkyl-substituted phenyl-α-naphthylamine, aralkyl-substituted phenyl-α-naphthylamine, alkylated p-phenylenediamine, and tetramethyl-diaminodiphenylamine; phenolic compounds such as 2,6-di-t-butyl-4-methylphenol; 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)benzene; and tetrakis[(methyl Examples include: len(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane (e.g., IRGANOX® 1010, manufactured by Ciba Specialty Chemicals); acryloyl-modified phenols; octadecyl-3,5-di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX® 1076, manufactured by Ciba Specialty Chemicals); phosphite esters; phosphonic acid esters; hydroxylamines; benzofuranone derivatives; combinations thereof; etc. As antioxidants, those described in Zweifel Hans et al., "Plastics Additives Handbook," Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 1, pp. 1-140 (2001) can be used.

[0098] Examples of UV stabilizers include benzophenone, benzotriazole, aryl esters, oxanilide, acrylic acid esters, formamidine, carbon black, hindered amines, nickel quenchers, phenolic compounds, metal salts, zinc compounds, and combinations thereof. UV stabilizers listed in Zweifel Hans et al.'s "Plastics Additives Handbook," Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 2, pp. 141-426 (2001) can be used.

[0099] Examples of heat stabilizers include phosphorus-based heat stabilizers, and commercially available examples include Ciba Specialty Chemicals' products: Irgaphos 38, 126, and P-EPQ, and Asahi Denka Kogyo's products: Adekastab PEP-4C, 11C, 24, and 36.

[0100] Examples of flame retardants include halogen-based organic flame retardants such as polybromodiphenyl ether, ethylene bisbrominated phthalimide, bis(brominated phenyl)ethane, bis(brominated phenyl) terephthalamide, and perchloropentacyclodecane; phosphorus-based organic flame retardants; nitrogen-based organic flame retardants; and inorganic flame retardants such as antimony trioxide, aluminum hydroxide, and magnesium hydroxide.

[0101] Examples of crosslinking agents include organic peroxides such as alkyl peroxides, aryl peroxides, peroxyesters, peroxycarbonates, diacyl peroxides, peroxyketals, and cyclic peroxides; silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltriacetoxysilane, vinylmethyldimethoxysilane, and 3-methacryloyloxypropyltrimethoxysilane; and radical crosslinking agents having multiple (preferably three or more) carbon-carbon double bonds in the molecule, such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and tolcrylformal. Crosslinking agents described in Zweifel Hans et al.'s "Plastics Additives Handbook," Hanser Gardner Publications, Cincinnati, Ohio, 5th edition, Chapter 14, pp. 725-812 (2001) can be used. Among these, radical crosslinking agents are preferred, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and tolacrylic formal are more preferred, and trimethylolpropane triacrylate and trimethylolpropane trimethacrylate are even more preferred.

[0102] The amount of these additives added is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, as a mass ratio to the thermoplastic polyurethane resin elastomer. Furthermore, the amount of additives added is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less. The above-mentioned additives may be used individually, or two or more may be used in any combination and ratio.

[0103] Furthermore, in this embodiment, thermoplastic polyurethane resin elastomer can also be used by compounding it with other thermoplastic polyurethane resin elastomers, such as vinyl chloride-based, styrene-based, polyolefin-based, polydiolefin-based, polyester-based, amide-based, and silicone-based thermoplastic elastomers.

[0104] (Layer (b) mainly composed of a resin other than thermoplastic urethane resin) The layer (b) mainly composed of a resin other than thermoplastic urethane resin is preferably a layer laminated on the layer (a) mainly composed of thermoplastic urethane resin. Figure 1 is a cross-sectional view illustrating the structure of the co-extruded multilayer film of this embodiment. As shown in Figure 1, it is preferable that layer (a) 2 and layer (b) 4 are laminated in direct contact.

[0105] The lamination configuration of each layer in the co-extruded multilayer film of this embodiment is not particularly limited. For example, it may be a configuration such as layer (a) / layer (b), layer (a) / layer (b) / layer (a), layer (b) / layer (a) / layer (b), layer (a) / layer (b) / layer (a) / layer (b), or layer (a) / layer (b) / layer (a). In particular, it is preferable that at least one of the outermost layers is layer (b), and both outermost layers may be layer (b).

[0106] In this embodiment, layer (b) is composed of a resin other than thermoplastic urethane resin. In particular, the resin other than thermoplastic urethane resin that constitutes layer (b) is preferably at least one selected from polyester resins and polycarbonate resins. By using the above resin as the resin that constitutes layer (b), the interlayer adhesion with layer (a) can be more effectively improved. Furthermore, by using the above resin as the resin that constitutes layer (b), the tensile storage modulus and impact resistance of the co-extruded multilayer film can be more effectively improved.

[0107] In accordance with JIS K7210-1 Method A (2014), a high-efficiency flow tester (Shimadzu Corporation, "CFT-500D") was used with a temperature of 200°C, a preheating time of 5 minutes, and a shear rate of 1.0 × 10⁻⁶. ２ The melt viscosity of layer (b), measured under / sec conditions, is 0.05 × 10⁻⁶. ３ It is preferable that the concentration be Pa·s or higher, and 0.06 × 10 ３ It is more preferable that the concentration be Pa·s or higher, and 0.07 × 10 ３ It is even more preferable that the viscosity is Pa·s or higher. Also, the melt viscosity of layer (b) is 1.00 × 10⁻⁶. ４ It is preferable that it be Pa·s or less, and 9.50 × 10 ３ It is more preferable that it be Pa·s or less, and 9.00 × 10 ３ It is even more preferable that the value is Pa·s or less.

[0108] (Polyester resin) The polyester resin can be any resin containing a polyester condensation polymer that includes a dicarboxylic acid component and a glycol component.

[0109] Examples of dicarboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, benzophenone dicarboxylic acid, anthracene dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid and 4,4'-dicyclohexyl dicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, azelaic acid, and dimer acid; and alicyclic dicarboxylic acids such as hexahydroterephthalic acid, 1,3-adamantanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid.

[0110] The polyester resin preferably contains terephthalic acid in a proportion of 75 mol% or more of the total dicarboxylic acid components, and more preferably in a proportion of 80 mol% or more, and more preferably in a proportion of 85 mol% or more.

[0111] Polyester resins may further contain glycol components other than ethylene glycol. Examples of glycol components other than ethylene glycol include aromatic diols such as diethylene glycol, 1,4-chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxybenzophenone, and p-xylene glycol, as well as aliphatic and alicyclic diols such as 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol.

[0112] From the viewpoint of extrusion moldability, the polyester resin is preferably amorphous polyester. Specifically, the polyester resin is subjected to a high-temperature flow tester (Shimadzu Corporation, "CFT-500D") in accordance with JIS K7210-1 Method A (2014) at a temperature of 200°C, a preheating time of 5 minutes, and a shear rate of 1.0 × 10⁻⁶ ２ The melt viscosity measured under / sec conditions was 0.05 × 10⁻⁶. ３ It is preferable that the concentration be Pa·s or higher, and 0.06 × 10 ３ It is more preferable that the concentration be Pa·s or higher, and 0.07 × 10 ３ It is even more preferable that it be Pa·s or higher. Also, 1.00 × 10 ４ It is preferable that it be Pa·s or less, and 9.50 × 10 ３ It is more preferable that it be Pa·s or less, and 9.00 × 10 ３ It is even more preferable that the value is Pa·s or less.

[0113] The polyester resin preferably contains structural units derived from biomass resources. In this case, it is preferable that the dicarboxylic acid component and / or diol component are raw materials derived from biomass resources, and more preferably that the diol component is a raw material derived from biomass resources. For example, it is preferable that ethylene glycol is a raw material derived from biomass. The content of structural units derived from biomass resources is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on the total mass of the polyester resin. The upper limit of the content of structural units derived from biomass resources is usually 99% by mass or less. The biomass resources mentioned above can be similarly exemplified as biomass resources.

[0114] Biomass-derived ethylene glycol can be obtained from ethanol produced using biomass as a raw material (biomass ethanol). Specifically, biomass-derived ethylene glycol can be obtained by producing ethylene glycol from biomass ethanol via ethylene.

[0115] (Polycarbonate resins) Polycarbonate resins are compounds that have structural units derived from dihydroxy compounds and carbonate bonds. Polycarbonate resins may be homopolycarbonates or copolymerized polycarbonate resins.

[0116] Copolymerized polycarbonate resins may be copolymerized (hereinafter also referred to as copolymerized polycarbonate resin (X)) by using two or more dihydroxy compounds in a polycarbonate composed of multiple carbonate units. Alternatively, copolymerized polycarbonate resins may be copolymerized (hereinafter sometimes referred to as copolymerized polycarbonate resin (Y)) by having units other than carbonate units in their molecules. However, copolymerized polycarbonate resin (Y) may also use two or more dihydroxy compounds.

[0117] The copolymerized polycarbonate resin (Y) may have units other than carbonate units in addition to the carbonate units, and examples include copolymers having units with a siloxane structure, units with a phosphorus atom, units with an anthraquinone structure, units with an olefin-based structure such as polystyrene, and ester units. The copolymerized polycarbonate resin (Y) is preferably a copolymer having units with a siloxane structure and ester units, and among these, a polyester carbonate copolymer resin having both carbonate units and ester units is more preferred. The carbonate unit referred to here consists of a carbonate bond and a structural unit derived from a dihydroxy compound, and specifically has a structure represented by the following formula (1), and is a unit that does not contain ester bonds other than carbonate bonds. The ester unit is as described later.

[0118]

[0119] However, in equation (1), R １ This is a structural unit derived from a dihydroxy compound.

[0120] Examples of dihydroxy compounds used in polycarbonate resins include aromatic dihydroxy compounds, aliphatic dihydroxy compounds, and alicyclic dihydroxy compounds. However, it is preferable that the polycarbonate resin has structural units derived from aromatic dihydroxy compounds. Having structural units derived from aromatic dihydroxy compounds makes it easier to improve the heat resistance of the polycarbonate resin.

[0121] Polycarbonate resins may be produced using any known method, such as the phosgene method, the transesterification method, and the pyridine method, but the phosgene method and the transesterification method are preferred. The phosgene method is a method for obtaining polycarbonate resins by reacting a dihydroxy compound with phosgene and then carrying out interfacial polymerization in the presence of a polymerization catalyst. The transesterification method is a production method in which a dihydroxy compound and a diester carbonate are reacted with a basic catalyst, and an acidic substance to neutralize this basic catalyst, and then molten transesterification polymerization is carried out.

[0122] Examples of diester carbonates include diphenyl carbonate, ditrile carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(biphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate, among which diphenyl carbonate is preferred.

[0123] In polycarbonate resins, when incorporating units other than carbonate units into the molecule, such as in polyester carbonate copolymer resins, it is advisable to mix components for obtaining the units other than carbonate units into the reaction system of each of the above manufacturing methods. For example, in the case of polyester carbonate copolymer resins, a polyester prepolymer can be added to the reaction system.

[0124] Examples of polyester prepolymers include polylactone prepolymers and polyesters obtained by polycondensation of dicarboxylic acids and dihydroxy compounds. In the case of polyester carbonate copolymer resins, they can also be produced by polymerization using a combination of dihydroxy compounds, dicarboxylic acids or their derivatives (such as dicarboxylic acid esters), and diester carbonates.

[0125] Bisphenol is preferred as the aromatic dihydroxy compound used in polycarbonate resins. Specific examples of bisphenol include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP), 2,2-bis(4-hydroxyphenyl)hexafluoropropane (bisphenol AF), 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), bis(4-hydroxyphenyl)diphenylmethane (bisphenol BP), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol E), bis(4-hydroxyphenyl)methane (bisphenol F), 2,2-bis( Examples include 4-hydroxy-3-isopropylphenyl)propane (bisphenol G), 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol M), bis(4-hydroxyphenyl)sulfone (bisphenol S), 1,4-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol P), 5,5'-(1-methylethylidene)-bis[1,1'-(bisphenyl)-2-ol]propane (bisphenol PH), 1,1-bis(4-hydroxyphenyl)3,3,5-trimethylcyclohexane (bisphenol TMC), and 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z). In polycarbonate resins, bisphenol may be used alone or in combination of two or more types.

[0126] Aliphatic dihydroxy compounds used in polycarbonate resins are not particularly limited in terms of the number of carbon atoms, but preferably have about 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms. Specifically, examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 2-ethyl-1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, hydrogenated dilinoleyl glycol, hydrogenated dioleyl glycol, and the like. Preferably, at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol is included, and more preferably, at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol is included.

[0127] The structural units derived from the alicyclic dihydroxy compound preferably include at least one of a five-membered ring structure or a six-membered ring structure, and the six-membered ring structure may be fixed in a chair-like or boat-like shape by covalent bonds. The number of carbon atoms in the alicyclic dihydroxy compound is, for example, 5 to 70, preferably 6 to 50, and more preferably 8 to 30. As the alicyclic dihydroxy compound, at least one selected from cyclohexanedimethanol, tricyclodecanedimethanol, adamantanediol, and pentacyclopentadecanedimethanol is preferred, and from the viewpoint of economy and heat resistance, cyclohexanedimethanol or tricyclodecanedimethanol is more preferred, and cyclohexanedimethanol is even more preferred. Of the cyclohexanedimethanol, 1,4-cyclohexanedimethanol is particularly preferred because it is readily available industrially.

[0128] Polycarbonate resin was subjected to a high-efficiency flow tester (Shimadzu Corporation, "CFT-500D") in accordance with JIS K7210-1 Method A (2014), at a temperature of 200°C, a preheating time of 5 minutes, and a shear rate of 1.0 × 10⁻⁶. ２ The melt viscosity measured under / sec conditions was 0.05 × 10⁻⁶. ３ It is preferable that the concentration be Pa·s or higher, and 0.06 × 10 ３ It is more preferable that the concentration be Pa·s or higher, and 0.07 × 10 ３ It is even more preferable that it be Pa·s or higher. Also, 1.00 × 10 ４ It is preferable that it be Pa·s or less, and 9.50 × 10 ３ It is more preferable that it be Pa·s or less, and 9.00 × 10 ３ It is even more preferable that the value is Pa·s or less.

[0129] Polycarbonate resins preferably contain structural units derived from biomass resources. In this case, it is preferable that the dihydroxy compound and / or the compound having a carbonate bond is a raw material derived from biomass resources, and it is more preferable that the dihydroxy compound is a raw material derived from biomass resources. For example, isosorbide, isomannide, isoidette, 1,3-propanediol, 1,4-butanediol, and 1,10-decanediol are preferably raw materials derived from biomass. Among these, isosorbide is preferred from the viewpoint of excellent optical properties of the polycarbonate resin composition. The content of structural units derived from biomass resources is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. The upper limit of the content of structural units derived from biomass resources is usually 99% by mass or less. The biomass resources mentioned above can be similarly exemplified as biomass resources.

[0130] Polycarbonate resins containing structural units derived from biomass resources tend to have a lower glass transition temperature compared to general polycarbonate resins that do not contain structural units derived from biomass resources. For example, the Tg of polycarbonate resin containing structural units derived from biomass resources (DURABIO) is 100°C, while the Tg of general polycarbonate resins is 140-150°C. When the co-extruded multilayer film of this embodiment is used as a decorative film, the temperature range for secondary molding of the decorative film is 100-140°C. Therefore, polycarbonate resins containing structural units derived from biomass resources have a greater tensile elongation at break compared to general polycarbonate resins. This reduces the risk of breakage during secondary molding of the decorative film. Furthermore, the yield stress is also lower, which can more effectively improve the secondary moldability of the decorative film.

[0131] (Method for Manufacturing Co-Extruded Multilayer Film) This embodiment may also relate to the method for manufacturing the co-extruded multilayer film described above. The method for manufacturing the co-extruded multilayer film according to this embodiment preferably includes a step of supplying the thermoplastic urethane resin constituting layer (a) and a resin other than the thermoplastic urethane resin constituting layer (b) to an extruder, melting them, and then co-extruding them. That is, the method for manufacturing the co-extruded multilayer film according to this embodiment preferably includes a step of manufacturing the co-extruded multilayer film by a co-extrusion method. In each extruder, each polymer is heated above its melting point to form a molten polymer. The molten polymer is then extruded from the die and cooled and solidified on a rotating cooling drum to a temperature below the glass transition point of the polymer to obtain the co-extruded multilayer film.

[0132] The extrusion temperature in the extruder is preferably 170°C or higher, more preferably 175°C or higher, and even more preferably 180°C or higher. Furthermore, the extrusion temperature is preferably 220°C or lower, more preferably 215°C or lower, and even more preferably 210°C or lower.

[0133] In this embodiment, a step of stretching the unstretched co-extruded multilayer film may be provided. In the stretching step, the unstretched co-extruded multilayer film is first stretched in one direction using a roll or tenter type stretcher. At this time, the stretching temperature is usually 25 to 100°C, preferably 35 to 70°C, and the stretching ratio is usually 2.5 to 7 times, preferably 2.8 to 6 times. Next, it is preferable to stretch in a direction perpendicular to the first stretching direction. At this time, the stretching temperature is usually 50 to 100°C, and the stretching ratio is usually 3.0 to 7 times, preferably 4.0 times or more, more preferably 4.5 to 5.0 times. In addition, in the stretching step, a method of performing unidirectional stretching in two or more stages can also be employed.

[0134] Then, it is preferable to continue the heat-setting process at a temperature of 100 to 140°C under tension or under relaxation of 30% or less. In this way, a biaxially oriented multilayer film is obtained. The heat-setting process may be carried out in two or more steps at different temperatures. Alternatively, cooling may be performed in a cooling zone after the heat-setting process.

[0135] (Laminated Film) This embodiment may also relate to a laminated film having a printed layer on at least one surface of the co-extruded multilayer film described above.

[0136] The printed layer preferably contains a binder such as a polyvinyl resin, polyamide resin, polyester resin, acrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, or alkyd resin. In addition, the printed layer preferably contains a suitable pigment or dye as a coloring agent in addition to the above-mentioned resins.

[0137] Printing methods that can be used include, for example, gravure printing, offset printing, gravure-offset printing, flexographic printing, inkjet printing, and thermal transfer printing.

[0138] (Applications) The co-extruded multilayer film of this embodiment can be used, for example, in resin plates, films, sheets, tubes, hoses, belts, rolls, synthetic leather, shoe soles, automobile parts, motorcycles, ships, aircraft, mobility such as flying cars, escalator handrails, road sign components, etc. More specifically, it can be used in pneumatic equipment, painting equipment, analytical instruments, scientific and chemical instruments, metering pumps, water treatment equipment, industrial robots, etc., as well as tubes and hoses, spiral tubes, fire hoses, etc. It can also be used as belts such as round belts, V-belts, and flat belts in various transmission mechanisms, spinning machines, packaging machines, printing machines, etc. It can also be used as heel tops and soles of footwear, couplings, packing, ball joints, bushings, gears, rolls and other equipment parts, sports goods, leisure goods, watch straps, etc. Furthermore, as an automobile part, it can be used in oil stoppers, gearboxes, spacers, chassis parts, interior parts, tire chain substitutes, etc. Furthermore, it can be used for keyboard films, automotive films (exterior and interior films), coiled cords, cable sheaths, bellows, conveyor belts, flexible containers, binders, synthetic leather, dipping products, adhesives, etc. It is also suitable for automotive exterior films, interior and exterior decorative films, and interior synthetic leather sheets. Moreover, the co-extruded multilayer film of this embodiment can be used for marking films used on the surfaces of mobility devices such as automobiles, motorcycles, ships, aircraft, and flying cars, as well as for decorative films used on various resins, metals, and glass surfaces.

[0139] This embodiment may relate to an automotive exterior film, an interior / exterior decorative film, or an interior synthetic leather sheet having the co-extruded multilayer film described above. Furthermore, this embodiment may relate to the use of the co-extruded multilayer film described above for manufacturing an automotive exterior film, an interior / exterior decorative film, or an interior synthetic leather sheet. Moreover, this embodiment may relate to a method for manufacturing an automotive exterior film, an interior / exterior decorative film, or an interior synthetic leather sheet using the co-extruded multilayer film described above.

[0140] In recent years, there has been a strong demand for environmental protection and climate change prevention, particularly in clothing and automotive applications. The non-yellowing thermoplastic polyurethane resin elastomer of the present invention, which uses biomass-derived raw materials, is expected to solve these problems. Furthermore, there is a need to use raw materials derived from non-edible plants, which are desirable from an animal welfare perspective and avoid competition with human food supply issues as biomass resources. The co-extruded multilayer film of this embodiment is a next-generation film that can solve these problems.

[0141] The features of the present invention will be further described below with reference to examples and comparative examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following specific examples.

[0142] (Example 1) The raw materials used for the intermediate and outer layers are shown below. (1) Thermoplastic urethane resin-1 In a 5 L glass separable flask equipped with a stirrer, distillate trap, and pressure regulator, 1065.2 g of 1,4-butanediol (hereinafter sometimes referred to as "1,4BD") derived from petrochemicals, 280.9 g of 1,10-decanediol (hereinafter sometimes referred to as "1,10DD") derived from non-edible plants (castor oil), 2653.9 g of diphenyl carbonate (hereinafter sometimes referred to as "DPC"), and 7.2 mL of magnesium acetate tetrahydrate aqueous solution (concentration: 8.4 g / L, magnesium acetate tetrahydrate: 60 mg) were placed and the flask was purged with nitrogen gas. Under stirring, the internal temperature was raised to 160°C and the contents were heated and dissolved. After that, the pressure was reduced to 24 kPa over 2 minutes, and the reaction was carried out for 90 minutes while removing phenol from the system. Next, the pressure was reduced to 9.3 kPa over 90 minutes, and then further reduced to 0.7 kPa over 30 minutes to continue the reaction. After that, the temperature was raised to 170°C and the reaction was continued for 60 minutes while removing the phenol and unreacted dihydroxy compound from the system to obtain a polycarbonate diol-containing composition. Subsequently, 2.8 mL of 0.85% by mass aqueous phosphoric acid solution was added to deactivate the magnesium acetate and obtain a polycarbonate diol-containing composition.

[0143] The obtained polycarbonate diol-containing composition was fed into a thin-film distillation apparatus at a flow rate of approximately 20 g / min, and thin-film distillation was performed (temperature: 170°C, pressure: 53-67 Pa). The thin-film distillation apparatus had a diameter of 50 mm, a height of 200 mm, and an area of ​​0.0314 m². ２ A special-type molecular distillation apparatus, the MS-300, manufactured by Shibata Scientific Co., Ltd., with an internal capacitor and jacket, was used.

[0144] The phenol content of the polycarbonate diol obtained by thin-film distillation was 100 ppm by mass or less. The magnesium content was also 100 ppm by mass or less. The polycarbonate diol produced in this manner is referred to as "PCD1". The evaluation results of the properties and physical characteristics of PCD1 are shown in Table 1.

[0145] In the storage tank of an extrusion molding machine equipped with a stirrer, PCD1 preheated to 80°C, 4,4'-dicyclohexylmethane diisocyanate (hereinafter sometimes referred to as "H12MDI"), and 1,4-butanediol (hereinafter sometimes referred to as "1,4BD") were used in such a ratio of hydroxyl group equivalents (EIII) of PCD1, isocyanate equivalents (EI) of H12MDI, and hydroxyl group equivalents (EII) of 1,4BD to 1.00:3.70:2.72 ((EI) / ((EII)+(EIII))=0.995). Furthermore, Neostan U-830 (hereinafter U-830, manufactured by Nitto Kasei Co., Ltd.) was charged at a concentration of 2 ppm by mass relative to the total mass of PCD1 and H12MDI as a urethane catalyst. Next, all components were rapidly mixed in a mixer rotating at 2000 rpm using a metering pump, and then continuously supplied to a twin-screw extruder rotating in the same axis direction, maintaining an in-machine polymerization temperature in the range of 140°C to 220°C. The rotation speed at this time was controlled to 250 rpm, and the residence time in the extruder was controlled to 1 to 3 minutes. The strands continuously extruded at the die outlet were cooled in water and cut with a pelletizer. The pellets were then dried at 100°C for 24 hours. Thermoplastic urethane resin-1 was obtained in this manner. Thermoplastic urethane resin-1 has a hardness A90 and a melt viscosity of 0.11 × 10⁻⁶. ３ The tensile storage modulus was 79 MPa in Pa·s.

[0146] (2) Polyester resin SKYGREEN SF700 (manufactured by SK Chemical, melt viscosity 2.01 × 10) ３ (Pa·s, tensile storage modulus 1.9 GPa, amorphous polyester) (3) Polycarbonate resin DURABIO D5360R (manufactured by Mitsubishi Chemical Corporation, melt viscosity 4.43 × 10) ３ (4) Polyethylene resin Novatec LL UF230 (manufactured by Nippon Polyethylene Co., Ltd., melt viscosity 2.1 × 10) ３ Pa·s (Tensile storage modulus: 1.6 MPa)

[0147] (Tensile Storage Modulus) In accordance with JIS K7244-10 (2005), the tensile storage modulus E' of a co-extruded multilayer film was measured using a rheometer (TA Instruments, "DiscoveryHR2") at a vibration frequency of 10 Hz and in tensile mode at 23°C.

[0148] <Examples 1-4> Co-extruded multilayer films were manufactured by melting and kneading each raw material at 200°C with the composition and layer configuration shown in Table 2 below, and then extruding them from a laminating die at 200°C so that layer (a) and layer (b) had predetermined thicknesses.

[0149] <Examples 5 and 6> Each raw material was melt-kneaded at 200°C with the composition and layer configuration shown in Table 2 below, and extruded from a 200°C laminating die to produce a co-extruded multilayer film with a total thickness of 150 μm, in which the outer layer (layer (a)), intermediate layer (layer (b)), and outer layer (layer (a)) were laminated in this order.

[0150] <Comparative Example 1> A single-layer film made of thermoplastic urethane resin was produced by melting and kneading the raw materials shown in Table 2 below at 200°C and extruding them from a laminate die at 200°C.

[0151] <Comparative Examples 2 and 3> Co-extruded multilayer films were manufactured in the same manner as in Examples 1 to 4, with the compositions shown in Table 2 below, and with layers (a) and (b) having predetermined thicknesses.

[0152] [Evaluation] The co-extruded multilayer films obtained in the examples and comparative examples were evaluated for extrusion feasibility, melt viscosity, tensile storage modulus, and interlayer adhesion using the methods described below. The results are shown in Table 2.

[0153] (Tensile Storage Modulus) In accordance with JIS K7244-10 (2005), the tensile storage modulus E' in the TD (perpendicular to the transverse direction of the film formation flow) direction was measured using a rheometer (TA Instruments, "DiscoveryHR2") at a vibration frequency of 10 Hz and tensile mode at 23°C.

[0154] (Delamination properties) Co-extruded multilayer films were cut into 10 mm wide strips, delamination was initiated with tweezers, and the strips were peeled off by hand. The following criteria were used for evaluation: [Evaluation criteria] ○: Difficult to peel off by hand △: Can be peeled off slowly by hand ×: Can be easily peeled off by hand

[0155] (Handling) Co-extruded multilayer film (350 mm wide, 10 m long) was wound onto a 3-inch paper core and left at room temperature for 7 days. The co-extruded multilayer film was then unwound and evaluated according to the following criteria: ○: Easily unwound by hand ×: Difficult to unwound by hand

[0156] (Tensile elongation at break) Co-extruded multilayer film was cut into strips (test piece: width 10 mm, initial length 40 mm), and a tensile test was performed on a tensile testing machine (Shimadzu Universal Tester AG-XPlus) at a tensile speed of 200 mm / min in an atmosphere of 23°C or 120°C, and the length elongated before the test piece broke was measured.

[0157] (Puncture Impact Strength) The puncture impact strength of co-extruded multilayer film was measured in accordance with JIS K7211-2 (2006). At room temperature of 23°C, a hemispherical striker was struck and penetrated against a fixed co-extruded multilayer film surface at a speed of 3.0 m / sec. The striker was equipped with sensors to measure load and displacement, respectively, and the load at the time of impact and penetration was measured.

[0158] (Puncture elongation) The puncture elongation of the co-extruded multilayer film was measured in accordance with JIS K7211-2 (2006). At room temperature of 23°C, a hemispherical striker was struck and penetrated the fixed co-extruded multilayer film surface at a speed of 3.0 m / sec. The striker was equipped with sensors to measure load and displacement, respectively, and the amount of displacement at the time of penetration of the co-extruded multilayer film, that is, the depth to which the striker pushed the co-extruded multilayer film just before penetration, was measured.

[0159] (Yield Stress) Co-extruded multilayer film was cut into strips (test specimen: width 10 mm, initial length 40 mm), and a tensile test was performed on a tensile testing machine (Shimadzu Universal Testing Machine AG-XPlus) at a 120°C atmosphere and a tensile speed of 200 mm / min. The point at which the load did not increase or temporarily decreased was defined as the "yield point," and the load at the yield point was measured. The yield stress was calculated by dividing the load at the yield point by the initial cross-sectional area of ​​the test specimen.

[0160]

[0161] The co-extruded multilayer film of the example, in which a layer containing polyester resin or polycarbonate resin was laminated onto a layer containing polyurethane resin, exhibited a high tensile storage modulus and excellent interlayer adhesion. Furthermore, by setting the total thickness ratio of the polyurethane resin layer to the polyester resin or polycarbonate resin layer within a predetermined range, the tensile elongation at break could be increased. The co-extruded multilayer film of the example also exhibited excellent impact resistance. On the other hand, the single-layer film obtained in Comparative Example 1 had poor handling properties, and the co-extruded multilayer film obtained in Comparative Example 2 had a low tensile elongation at break because the total thickness ratio of the polyurethane resin layer to the polyester resin or polycarbonate resin layer was within a predetermined range. In addition, the co-extruded multilayer film of Comparative Example 3, in which a layer containing polyethylene resin (non-polar resin) was laminated onto a polyurethane resin layer, was obtained by extrusion molding, but exhibited peelability and therefore lacked practicality.

[0162] 2 layers (a) 4 layers (b) 10 Multilayer film

Claims

1. A co-extruded multilayer film comprising a layer (a) mainly composed of a thermoplastic urethane resin and a layer (b) mainly composed of a resin other than a thermoplastic urethane resin, wherein the resin constituting layer (b) is at least one selected from polyester resins and polycarbonate resins, the total thickness of layer (a) is 30 μm or more and 500 μm or less, the total thickness of layer (b) is 3 μm or more and 500 μm or less, the ratio of the total thickness of layer (a) to the total thickness of layer (b) (a / b) is 0.7 or more and less than 19, and the tensile storage modulus in at least one direction at 23°C is 200 MPa or more and 1700 MPa or less.

2. The co-extruded multilayer film according to claim 1, wherein the ratio (a / b) of the total thickness of layer (a) to the total thickness of layer (b) is 1 or more and less than 19.

3. The thermoplastic polyurethane resin elastomer is a thermoplastic polyurethane resin elastomer having structural units derived from an isocyanate compound (I), structural units derived from an aliphatic alcohol (II) having a number average molecular weight of less than 300 as determined from its hydroxyl value and having only hydroxyl groups as functional groups, and structural units derived from a polyol (III) having a number average molecular weight of 300 or more and 10,000 or less as determined from its hydroxyl groups, wherein the isocyanate compound (I) contains a total of 90 mol% or more of aliphatic isocyanate compounds containing two isocyanate groups and alicyclic isocyanate compounds containing two isocyanate groups, as described in claim 1.

4. The co-extruded multilayer film according to claim 3, wherein the aliphatic alcohol (II) contains 90 mol% or more of an aliphatic diol having 12 or fewer carbon atoms.

5. The co-extruded multilayer film according to claim 3, wherein the polyol (III) contains 80 mol% or more of polycarbonate diol (IIIA) comprising repeating structural units represented by the following formula (A) and / or repeating structural units represented by the following formula (B). (In formula (A), R １ R is a hydrocarbon group having 3 to 5 carbon atoms, in formula (B), ２ (This refers to a hydrocarbon group with 6 to 20 carbon atoms.) 6. The co-extruded multilayer film according to claim 3, wherein the hydroxyl group equivalent (EIII) of the polyol (III): isocyanate equivalent (EI) of the isocyanate compound (I): hydroxyl group equivalent (EII) of the aliphatic alcohol (II) is in an equivalent ratio of 1.0:2.0 to 6.0:1.0 to 5.0, and the equivalent ratio of 0.95 ≤ (EI) / ((EII) + (EIII)) ≤ 1.

05.

7. The co-extruded multilayer film according to claim 5, wherein the number average molecular weight of the polycarbonate diol (IIIA), determined from its hydroxyl value, is 500 or more and 5,000 or less.

8. The co-extruded multilayer film according to claim 3, wherein the thermoplastic polyurethane resin elastomer contains 10% by mass or more of structural units derived from biomass resources.

9. The co-extruded multilayer film according to claim 1, wherein the polyester resin or polycarbonate resin contains structural units derived from biomass resources.

10. The co-extruded multilayer film according to claim 1, wherein the tensile elongation at break in at least one direction at 23°C is 150% or more.

11. The co-extruded multilayer film according to claim 1, wherein the puncture impact strength at 23°C is 3.0 J or more.

12. A laminated film further having a printed layer on at least one surface of a co-extruded multilayer film according to any one of claims 1 to 11.

13. An automotive outer layer film having a co-extruded multilayer film according to any one of claims 1 to 11.

14. An interior and exterior decorative film having a co-extruded multilayer film according to any one of claims 1 to 11.

15. A synthetic leather sheet for interior use having a co-extruded multilayer film according to any one of claims 1 to 11.

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