Thermoplastic polyurethane resin composition and film

Abstract

To provide a thermoplastic polyurethane resin composition and a film which have relatively excellent coloring resistance and weather resistance.SOLUTION: The thermoplastic polyurethane resin composition contains a thermoplastic polyurethane resin and an additive. The thermoplastic polyurethane resin contains a reaction product of a polyisocyanate component and a polyol component. The polyol component contains a polycarbonate polyol. The additive contains a phosphorus-based antioxidant. The content of the phosphorus-based antioxidant is 0.02-0.50 pt.mass based on 100 pts.mass of the polycarbonate polyol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic polyurethane resin composition and a film. [Background technology]

[0002] Thermoplastic polyurethane resin (TPU) is a rubbery elastomer obtained by the reaction of polyisocyanate, high-molecular-weight polyol, and low-molecular-weight polyol. Thermoplastic polyurethane resin is molded into a film and used as a paint protection film (PPF) to protect the painted surfaces of automobiles.

[0003] More specifically, for example, a thermoplastic polyurethane resin and film obtained by the following method has been proposed. First, Irganox 245 (trade name, manufactured by BASF), Tinuvin 571 (trade name, manufactured by BASF), and Adekastab LA-72 (trade name, manufactured by ADEKA) are added to polycarbonate diol. Next, 1,4-bis(isocyanatomethyl)cyclohexane is mixed with the polycarbonate diol and additives to obtain an isocyanate-terminated prepolymer. Next, the isocyanate-terminated prepolymer is mixed with 1,4-butanediol to obtain a thermoplastic polyurethane resin. The thermoplastic polyurethane resin is pelletized and extrusion-molded to obtain a thermoplastic polyurethane resin film (see, for example, Patent Document 1 (Example 1)). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 065783 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, when polycarbonate diol is used as a raw material for a thermoplastic polyurethane resin, the thermoplastic polyurethane resin tends to be discolored. Therefore, when polycarbonate diol is used, improvement in discoloration resistance is required.

[0006] Furthermore, thermoplastic polyurethane resins are required to have relatively excellent weather resistance.

[0007] The present invention is a thermoplastic polyurethane resin composition and film having relatively excellent stain resistance and weather resistance. [Means for solving the problem]

[0008] The present invention [1] is a thermoplastic polyurethane resin composition containing a thermoplastic polyurethane resin and an additive, wherein the thermoplastic polyurethane resin contains a reaction product of a polyisocyanate component and a polyol component, the polyol component contains a polycarbonate polyol, and the additive contains a phosphorus-based antioxidant, the content of the phosphorus-based antioxidant being 0.02 to 0.50 parts by mass per 100 parts by mass of the polycarbonate polyol.

[0009] The present invention [2] includes the thermoplastic polyurethane resin composition according to the above [1], wherein the polycarbonate polyol contains a crystalline polycarbonate polyol.

[0010] The present invention [3] includes the thermoplastic polyurethane resin composition according to the above [1] or [2], wherein the phosphorus-based antioxidant contains at least one selected from the group consisting of a phosphite-based antioxidant, a phosphate-based antioxidant, and a phosphorus compound-based antioxidant.

[0011] The present invention [4] includes the thermoplastic polyurethane resin composition according to any one of the above [1] to [3], wherein the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane.

[0012] The present invention [5] comprises the thermoplastic polyurethane resin composition according to any one of the above [1] to [4], wherein the polyisocyanate component contains 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane, and the content of 1,4-bis(isocyanatomethyl)cyclohexane is 50 mol% or more based on the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane.

[0013] The present invention [6] includes the thermoplastic polyurethane resin composition according to any one of the above [1] to [5], wherein the additive further contains a hindered amine-based light stabilizer.

[0014] The present invention [7] includes the thermoplastic polyurethane resin composition according to the above [6], in which the hindered amine light stabilizer contains two or more hindered amine groups in one molecule.

[0015] The present invention [8] includes the thermoplastic polyurethane resin composition according to the above [6] or [7], in which the hindered amine light stabilizer contains three or more hindered amine groups in one molecule, or two hindered amine groups and one or more hindered phenol groups in one molecule.

[0016] The present invention [9] includes a film containing the thermoplastic polyurethane resin composition according to any one of the above [1] to [8]. [Effects of the Invention]

[0017] The thermoplastic polyurethane resin composition and film of the present invention contain a thermoplastic polyurethane resin and an additive. The thermoplastic polyurethane resin contains a reaction product of a polyisocyanate component and a polyol component, and the polyol component contains a polycarbonate polyol. The additive contains a phosphorus-based antioxidant. The content of the phosphorus-based antioxidant relative to the polycarbonate polyol is adjusted to a predetermined range.

[0018] Therefore, the thermoplastic polyurethane resin composition and film of the present invention have relatively excellent coloration resistance and weather resistance. DETAILED DESCRIPTION OF THE INVENTION

[0019] 1. Thermoplastic polyurethane resin composition The thermoplastic polyurethane resin composition of the present invention contains a thermoplastic polyurethane resin and an additive. Preferably, the thermoplastic polyurethane resin composition comprises a thermoplastic polyurethane resin and an additive. In other words, the thermoplastic polyurethane resin composition is preferably a thermoplastic polyurethane resin to which an additive has been added.

[0020] (1) Thermoplastic polyurethane resin The thermoplastic polyurethane resin is obtained by reacting a polyisocyanate component with a polyol component. In other words, the thermoplastic polyurethane resin contains a reaction product of the polyisocyanate component and the polyol component. Preferably, the thermoplastic polyurethane resin is a reaction product of the polyisocyanate component and the polyol component.

[0021] [Polyisocyanate component] The polyisocyanate component includes, for example, a polyisocyanate monomer and a polyisocyanate derivative.

[0022] Examples of polyisocyanate monomers include aliphatic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates. These polyisocyanate monomers can be used alone or in combination of two or more.

[0023] Examples of the aliphatic polyisocyanate include chain aliphatic polyisocyanates and alicyclic polyisocyanates.

[0024] Examples of linear aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 1,2-propane diisocyanate, 1,2-butane diisocyanate, 2,3-butane diisocyanate, 1,3-butane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate. These can be used alone or in combination of two or more.

[0025] Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and methylenebis(cyclohexyl isocyanate) (H 12 MDI) and bis(isocyanatomethyl)cyclohexane (H6XDI). These can be used alone or in combination of two or more.

[0026] Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), toluidine diisocyanate (TODI), paraphenylene diisocyanate, and naphthalene diisocyanate (NDI). These can be used alone or in combination of two or more.

[0027] Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate (XDI) and tetramethyl xylylene diisocyanate (TMXDI), which can be used alone or in combination of two or more.

[0028] Examples of polyisocyanate derivatives include modified products obtained by modifying the above polyisocyanate monomers using known methods. Examples of polyisocyanate derivatives include polymers, isocyanurate modified products, allophanate modified products, polyol adducts, biuret modified products, urea modified products, oxadiazinetrione modified products, and carbodiimide modified products. Examples of polyisocyanate derivatives also include polymethylene polyphenylene polyisocyanate. These can be used alone or in combination of two or more types.

[0029] From the viewpoints of mechanical properties, appearance, and coloring resistance, the polyisocyanate component is preferably a polyisocyanate monomer, more preferably an alicyclic polyisocyanate, and even more preferably bis(isocyanatomethyl)cyclohexane (H6XDI).

[0030] That is, from the viewpoints of heat resistance, mechanical properties, and coloration resistance, the polyisocyanate component preferably contains a polyisocyanate monomer, more preferably contains an alicyclic polyisocyanate, and even more preferably contains bis(isocyanatomethyl)cyclohexane (H6XDI).

[0031] Furthermore, from the viewpoints of heat resistance, mechanical properties, and coloration resistance, the polyisocyanate component preferably comprises a polyisocyanate monomer, more preferably comprises an alicyclic polyisocyanate, and even more preferably comprises bis(isocyanatomethyl)cyclohexane (H6XDI).

[0032] Examples of bis(isocyanatomethyl)cyclohexane include 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,2-bis(isocyanatomethyl)cyclohexane. These may be used alone or in combination of two or more.

[0033] From the viewpoints of mechanical properties and heat resistance, preferred are 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane. That is, from the viewpoints of mechanical properties and heat resistance, the polyisocyanate component preferably contains 1,4-bis(isocyanatomethyl)cyclohexane and / or 1,3-bis(isocyanatomethyl)cyclohexane, more preferably contains 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane, and even more preferably consists of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane.

[0034] 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) has stereoisomers, including cis-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred to as cis 1,4 isomer) and trans-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred to as trans 1,4 isomer).

[0035] 1,4-bis(isocyanatomethyl)cyclohexane contains, for example, a trans-1,4 isomer (trans isomer) and a cis-1,4 isomer (cis isomer), with the total amount of the trans-1,4 isomer and the cis-1,4 isomer being 100 mol %.

[0036] The content of the trans-1,4 isomer (trans isomer) relative to the total moles of 1,4-bis(isocyanatomethyl)cyclohexane is, for example, 60 to 99.5 mol%, preferably 70 to 99 mol%, more preferably 75 to 96 mol%, and even more preferably 80 to 90 mol%. In other words, the content of the cis-1,4 isomer (cis isomer) relative to the total moles of 1,4-bis(isocyanatomethyl)cyclohexane is, for example, 0.5 to 40 mol%, preferably 1 to 30 mol%, more preferably 4 to 25 mol%, and even more preferably 10 to 20 mol%.

[0037] 1,4-bis(isocyanatomethyl)cyclohexane is produced by a known method. Methods for producing 1,4-bis(isocyanatomethyl)cyclohexane are described in, for example, WO 2009 / 051114 and WO 2019 / 069802.

[0038] 1,4-bis(isocyanatomethyl)cyclohexane may be a monomer or a modified product. Examples of modified products include uretdione modified products, isocyanurate modified products, iminooxadiazinedione, biuret modified products, allophanate modified products, polyol adducts, oxadiazinetrione modified products, and carbodiimide modified products. These may be used alone or in combination of two or more types. 1,4-bis(isocyanatomethyl)cyclohexane is preferably a monomer.

[0039] The 1,3-bis(isocyanatomethyl)cyclohexane (1,3-H6XDI) is not particularly limited, and known 1,3-bis(isocyanatomethyl)cyclohexane may be used.

[0040] 1,3-bis(isocyanatomethyl)cyclohexane may be a monomer or a modified product. Examples of modified products include uretdione modified products, isocyanurate modified products, iminooxadiazinedione, biuret modified products, allophanate modified products, polyol adducts, oxadiazinetrione modified products, and carbodiimide modified products. These may be used alone or in combination of two or more types. 1,3-bis(isocyanatomethyl)cyclohexane is preferably a monomer.

[0041] When the polyisocyanate component contains 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane, the content ratio of 1,4-bis(isocyanatomethyl)cyclohexane and the content ratio of 1,3-bis(isocyanatomethyl)cyclohexane are appropriately set depending on the purpose and application.

[0042] More specifically, from the viewpoints of heat resistance, mechanical properties, and moldability, the content of 1,4-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 10 mol% or more, preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and particularly preferably 65 mol% or more. Furthermore, the content of 1,4-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 99 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, and particularly preferably 75 mol% or less.

[0043] That is, the content of 1,4-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 10 to 99 mol%, preferably 30 to 90 mol%, more preferably 50 to 85 mol%, even more preferably 60 to 80 mol%, and particularly preferably 65 to 75 mol%.

[0044] The content of 1,3-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 1 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and particularly preferably 25 mol% or more. The content of 1,3-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 90 mol% or less, preferably 70 mol% or less, more preferably 50 mol% or less, even more preferably 40 mol% or less, and particularly preferably 35 mol% or less.

[0045] That is, the content of 1,3-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane is, for example, 1 to 90 mol%, preferably 10 to 70 mol%, more preferably 15 to 50 mol%, even more preferably 20 to 40 mol%, and particularly preferably 25 to 35 mol%.

[0046] The polyisocyanate component is produced by a known method, and may contain additives described below in appropriate proportions.

[0047] [Polyol component] The polyol component contains a high molecular weight polyol as an essential component.

[0048] (High molecular weight polyol) High molecular weight polyols are organic compounds with two or more hydroxyl groups in the molecule and a relatively high molecular weight. A relatively high molecular weight means that the number average molecular weight (polystyrene equivalent molecular weight measured by GPC (hereinafter the same)) exceeds 400.

[0049] The high-molecular-weight polyol contains a polycarbonate polyol as an essential component. In other words, the polyol component contains a polycarbonate polyol as an essential component. The polycarbonate polyol improves the stretchability, heat resistance, and finger print recovery of the thermoplastic polyurethane resin in a balanced manner. The polycarbonate polyol also improves the mechanical properties, chemical resistance, and hydrolysis resistance of the thermoplastic polyurethane resin.

[0050] Examples of polycarbonate polyols include crystalline polycarbonate polyols and amorphous polycarbonate polyols.

[0051] Crystalline polycarbonate polyol is a polycarbonate polyol that is solid at 25°C. A solid state refers to a state in which the viscosity at 25°C measured with an E-type viscometer exceeds 500,000 mPa·s.

[0052] Examples of crystalline polycarbonate polyols include ring-opening polymerization products of ethylene carbonate using a polyhydric alcohol as an initiator. Examples of polyhydric alcohols that can be used as initiators include dihydric alcohols having 2 to 8 carbon atoms and trihydric alcohols having 2 to 8 carbon atoms. Examples of dihydric alcohols having 2 to 8 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, diethylene glycol, and triethylene glycol. Examples of trihydric alcohols having 2 to 8 carbon atoms include glycerin, trimethylolethane, and trimethylolpropane. These can be used alone or in combination of two or more. Preferably, the polyhydric alcohol is a dihydric alcohol.

[0053] The method for ring-opening polymerization of ethylene carbonate with a polyhydric alcohol is not particularly limited, and any known method can be used.

[0054] The number average molecular weight (polystyrene equivalent molecular weight) of the crystalline polycarbonate polyol is, for example, more than 400 and not more than 10,000. The number average molecular weight (polystyrene equivalent molecular weight) of the crystalline polycarbonate polyol is preferably 500 to 8,000, more preferably 500 to 5,000, even more preferably 1,000 to 3,000, and particularly preferably 1,000 to 2,000.

[0055] The average number of hydroxyl groups in the crystalline polycarbonate polyol is, for example, 1.8 to 4, preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2. In other words, particularly preferred examples of the crystalline polycarbonate polyol include crystalline polycarbonate diols.

[0056] Amorphous polycarbonate polyol is a polycarbonate polyol that is liquid at 25°C. The term "liquid" refers to a state in which the viscosity at 25°C measured with an E-type viscometer is 500,000 mPa·s or less.

[0057] Amorphous polycarbonate polyols can be obtained, for example, by modifying the above-mentioned crystalline polycarbonate polyol with a polyhydric alcohol as a modifying agent. Examples of polyhydric alcohols as modifying agents include dihydric alcohols having 4 to 10 carbon atoms. Examples of dihydric alcohols having 4 to 10 carbon atoms include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol. These can be used alone or in combination of two or more.

[0058] The method for modifying the ring-opening polymer of ethylene carbonate with a dihydric alcohol is not particularly limited, and any known method can be used. For example, ethylene carbonate is ring-opening polymerized by a known method using a dihydric alcohol as an initiator, and then the resulting ring-opening polymer is copolymerized with the dihydric alcohol as a modifying agent.

[0059] The number average molecular weight (polystyrene equivalent molecular weight) of the amorphous polycarbonate polyol is, for example, more than 400 and, for example, not more than 10,000. The number average molecular weight (polystyrene equivalent molecular weight) of the amorphous polycarbonate polyol is preferably 500 to 8,000, more preferably 500 to 5,000, even more preferably 1,000 to 3,000, and particularly preferably 1,000 to 2,000.

[0060] The average number of hydroxyl groups in the amorphous polycarbonate polyol is, for example, 1.8 to 4, preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2. In other words, particularly preferred examples of the amorphous polycarbonate polyol include amorphous polycarbonate diols.

[0061] The polycarbonate polyols may be used alone or in combination of two or more. As the polycarbonate polyol, from the viewpoint of achieving a balanced improvement in the stretching properties (return force), heat resistance, and finger print recovery of the thermoplastic polyurethane resin, a crystalline polycarbonate polyol is preferably used. That is, from the viewpoint of achieving a balanced improvement in the stretching properties (return force), heat resistance, and finger print recovery of the thermoplastic polyurethane resin, the high-molecular-weight polyol preferably contains, and more preferably consists of, a crystalline polycarbonate polyol.

[0062] The number average molecular weight (polystyrene equivalent molecular weight) of the polycarbonate polyol is, for example, more than 400 and, for example, not more than 10,000. The number average molecular weight (polystyrene equivalent molecular weight) of the polycarbonate polyol is preferably 500 to 8,000, more preferably 500 to 5,000, even more preferably 1,000 to 3,000, and particularly preferably 1,000 to 2,000.

[0063] The average number of hydroxyl groups in the polycarbonate polyol is, for example, 1.8 to 4, preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2. In other words, particularly preferred examples of the polycarbonate polyol include polycarbonate diols.

[0064] The high-molecular-weight polyol may optionally contain other high-molecular-weight polyols, which are high-molecular-weight polyols other than polycarbonate polyols.

[0065] Other high molecular weight polyols include, for example, polyether polyols, polyester polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used alone or in combination of two or more.

[0066] The content of the other high molecular weight polyols relative to the total amount of high molecular weight polyols is, for example, 50 mass % or less, preferably 30 mass % or less, more preferably 10 mass % or less, and particularly preferably 0 mass %.

[0067] That is, the content of the polycarbonate polyol is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass, relative to the total amount of the high molecular weight polyol. In other words, the high molecular weight polyol particularly preferably consists of a polycarbonate polyol.

[0068] The number average molecular weight (polystyrene equivalent molecular weight) of the high molecular weight polyol exceeds 400 and is, for example, not more than 10,000. The number average molecular weight (polystyrene equivalent molecular weight) of the high molecular weight polyol is preferably 500 to 8,000, more preferably 500 to 5,000, even more preferably 1,000 to 3,000, and particularly preferably 1,000 to 2,000.

[0069] The content ratio of the high-molecular-weight polyol is appropriately set depending on the purpose and application, and preferably, the content ratio of the high-molecular-weight polyol is appropriately set so that the hard segment concentration of the thermoplastic polyurethane resin falls within a desired range.

[0070] The content of the high molecular weight polyol is, for example, 10 to 95 mol %, preferably 20 to 70 mol %, and more preferably 30 to 50 mol %, based on the total amount of the high molecular weight polyol and the low molecular weight polyol.

[0071] (Low molecular weight polyol) The polyol component can optionally contain a low molecular weight polyol, and preferably contains a low molecular weight polyol.

[0072] That is, the polyol component preferably contains both a high-molecular-weight polyol and a low-molecular-weight polyol, and more preferably consists of a high-molecular-weight polyol and a low-molecular-weight polyol.

[0073] Low-molecular-weight polyols are organic compounds that have two or more hydroxyl groups in the molecule and have a relatively low molecular weight. The term "relatively low molecular weight" refers to a number-average molecular weight of 400 or less.

[0074] Examples of low-molecular-weight polyols include low-molecular-weight diols having 2 to 6 carbon atoms, low-molecular-weight diols having 7 or more carbon atoms, and low-molecular-weight polyols having a valence of 3 or more. These can be used alone or in combination of two or more. Preferred low-molecular-weight polyols include low-molecular-weight diols having 2 to 6 carbon atoms. In other words, the low-molecular-weight polyol preferably contains a low-molecular-weight diol having 2 to 6 carbon atoms, and more preferably consists of a low-molecular-weight diol having 2 to 6 carbon atoms.

[0075] The low molecular weight diol having 2 to 6 carbon atoms is a compound having 2 to 6 carbon atoms in one molecule, two hydroxyl groups in one molecule, and a molecular weight of 400 or less.

[0076] Examples of low-molecular-weight diols having 2 to 6 carbon atoms include alkanediols having 2 to 6 carbon atoms, etherdiols having 2 to 6 carbon atoms, and alkenediols having 2 to 6 carbon atoms. Examples of alkanediols having 2 to 6 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol (1,4-BD), 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2,2-dimethyl-1,3-propanediol. Examples of etherdiols having 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of alkenediols having 2 to 6 carbon atoms include 1,4-dihydroxy-2-butene. These can be used alone or in combination.

[0077] The carbon number of the low-molecular-weight diol having 2 to 6 carbon atoms is 2 to 6, preferably 3 to 5, and particularly preferably 4. As the low-molecular-weight diol having 2 to 6 carbon atoms, preferably, an alkanediol having 2 to 6 carbon atoms is used, more preferably, an alkanediol having 3 to 5 carbon atoms is used, and even more preferably, 1,4-butanediol is used.

[0078] The content ratio of the low-molecular-weight polyol is appropriately set depending on the purpose and application, and preferably, the content ratio of the low-molecular-weight polyol is appropriately set so that the hard segment concentration of the thermoplastic polyurethane resin falls within a desired range.

[0079] For example, the content of the low molecular weight polyol is, for example, 5 to 90 mol %, preferably 30 to 80 mol %, more preferably 50 to 70 mol %, based on the total amount of the high molecular weight polyol and the low molecular weight polyol.

[0080] (2) Manufacturing method of thermoplastic polyurethane resin As described above, the thermoplastic polyurethane resin is a reaction product of raw material components, that is, a polyisocyanate component and a polyol component. In other words, the thermoplastic polyurethane resin is produced by reacting the polyisocyanate component with the polyol component.

[0081] Details of the method for producing the thermoplastic polyurethane resin will be described later as a method for producing a thermoplastic polyurethane resin composition.

[0082] (3) Additives The additive contains a phosphorus-based antioxidant as an essential component.

[0083] [Phosphorus-based antioxidant] The phosphorus-based antioxidant is an antioxidant containing phosphorus. Examples of the phosphorus-based antioxidant include phosphite-based antioxidants, phosphate-based antioxidants, and phosphorus compound-based antioxidants. These can be used alone or in combination of two or more. From the viewpoint of reducing coloration, the phosphorus-based antioxidant preferably contains at least one selected from the group consisting of phosphite-based antioxidants, phosphate-based antioxidants, and phosphorus compound-based antioxidants.

[0084] (Phosphite ester antioxidant) A phosphite antioxidant is a compound that has at least one phosphite structure in its molecule.

[0085] Examples of the phosphite-based antioxidant include organic phosphite compounds.Examples of organic phosphite compounds include trimethyl phosphite, triethyl phosphite, tributyl phosphite, tris(2-ethylhexyl) phosphite, triisooctyl phosphite, tridecyl phosphite, triisodecyl phosphite, tridodecyl phosphite, tris(tridecyl) phosphite, trioleyl phosphite, tristearyl phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, and phenyldiisooctyl Phosphite, phenyl diisodecyl phosphite, diphenyl mono(2-ethylhexyl) phosphite, diphenyl isooctyl phosphite, diphenyl monodecyl phosphite, diphenyl monoisodecyl phosphite, diphenyl mono(tridecyl) phosphite, bis(nonylphenyl) dinonylphenyl phosphite, tetraphenyl dipropylene glycol diphosphite, poly(dipropylene glycol) phenyl phosphite, diisodecyl pentaerythritol diphosphite, bis(decyl) pentaerythritol diphosphite phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, tetra(tridecyl)-4,4'-isopropylidene diphenyl phosphite, trilauryl trithiophosphite, dimethyl hydrogen phosphite, dibutyl hydrogen phosphite, Examples include di(2-ethylhexyl)hydrogen phosphite, dilaurylhydrogen phosphite, dioleylhydrogen phosphite, diphenylhydrogen phosphite, diphenylmono(2-ethylhexyl)phosphite, diphenylmonodecyl phosphite, diphenylmono(tridecyl)phosphite, 4,4'-butylidenebis(3-methyl-6-t-butylphenylditridecyl phosphite), and tris(2,4-di-t-butylphenyl)phosphite. These can be used alone or in combination of two or more types.Preferred examples of the organic phosphite ester compound include bis(decyl)pentaerythritol diphosphite and tridecyl phosphite.

[0086] The phosphite ester-based antioxidants are also available as commercially available products. Examples of commercially available phosphite ester-based antioxidants include those sold under the trade names JPE-10 (bis(decyl)pentaerythritol diphosphite, manufactured by Johoku Chemical Industry Co., Ltd.), JP-310 (tridecyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), JP-360 (triphenyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), JP-304 (tributyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), JP-308E and JPE-308E (tris(2-ethylhexyl) phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), and JPE-318E (tristearyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd.). Examples of suitable phosphite include trade name JP-333E (tris(tridecyl)phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), trade name JPP-100 (tetraphenyldipropylene glycol diphosphite, manufactured by Johoku Chemical Industry Co., Ltd.), trade name JPH-1200 (4,4'-butylidenebis(3-methyl-6-t-butylphenylditridecyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd.), and trade name JP-650 (tris(2,4-di-t-butylphenyl)phosphite, manufactured by Johoku Chemical Industry Co., Ltd.). These can be used alone or in combination of two or more types.

[0087] (phosphate ester antioxidant) Phosphate ester antioxidants are compounds that have at least one phosphate ester structure in the molecule.

[0088] Examples of the phosphate ester-based antioxidant include organic phosphate ester compounds. Examples of organic phosphate ester compounds include butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, oleyl acid phosphate, isotridecyl acid phosphate, ammonium ethyl acid phosphate, diethylbenzyl phosphate, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, tris(butoxyethyl)phosphate, tris(2-ethylhexyl)phosphate, tris(2-chloroethyl)phosphate, tris(2-dichloropropyl)phosphate, triphenyl phosphate, butyl pyrophosphate, tricresyl phosphate, trixylenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphosphate, monobutyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, diisotridecyl phosphate, and monoisodecyl phosphate. These can be used alone or in combination of two or more. Preferred examples of the phosphate ester antioxidant include butoxyethyl acid phosphate and isotridecyl acid phosphate.

[0089] Phosphate ester antioxidants are also available as commercially available products. Examples of commercially available phosphate ester antioxidants include JP-506H (butoxyethyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd.), JP-513 (isotridecyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd.), JP-518-O (oleyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd.), and JP-508 (2-ethylhexyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd.). These can be used alone or in combination of two or more types.

[0090] The phosphorus compound-based antioxidant is a compound that contains phosphorus and does not have a phosphite ester structure or a phosphate ester structure in the molecule.

[0091] Examples of phosphorus compound-based antioxidants include non-phosphate organic compounds. Examples of non-phosphate organic compounds include phosphine compounds. Examples of phosphine compounds include triphenylphosphine, diphenylbutylphosphine, diphenyloctadecylphosphine, tris(p-tolyl)phosphine, tris(p-nonylphenyl)phosphine, tris(naphthyl)phosphine, diphenyl(hydroxymethyl)phosphine, diphenyl(acetoxymethyl)phosphine, diphenyl(β-ethylcarboxyethyl)phosphine, tris(p-chlorophenyl)phosphine, tris(p-fluorophenyl)phosphine, diphenylbenzylphosphine, diphenyl-β-cyanoethylphosphine, diphenyl(p-hydroxyphenyl)phosphine, diphenyl-1,4-dihydroxyphenyl-2-phosphine, and phenylnaphthylbenzylphosphine. These compounds can be used alone or in combination of two or more. Phosphine compounds are preferred, and triphenylphosphine is more preferred.

[0092] Phosphorus compound-based antioxidants are also available as commercially available products. For example, a commercially available phosphorus compound-based antioxidant is JC-263 (triphenylphosphine, manufactured by Johoku Chemical Industry Co., Ltd.). These can be used alone or in combination of two or more types.

[0093] The phosphorus-based antioxidants can be used alone or in combination of two or more. From the viewpoint of weather resistance, preferred examples of the phosphorus-based antioxidant include phosphite-based antioxidants and phosphate-based antioxidants, and more preferred examples include phosphite-based antioxidants.

[0094] (Phosphorus-based antioxidant content) The amount of the phosphorus-based antioxidant is adjusted according to the amount of the polycarbonate polyol. That is, the amount of the antioxidant is usually adjusted as a proportion (phr) to the total amount of the thermoplastic polyurethane resin (the total amount of the polyisocyanate component and the polyol component).

[0095] On the other hand, when the polycarbonate polyol is used as a raw material for a thermoplastic polyurethane resin, the thermoplastic polyurethane resin is likely to be discolored. Therefore, when a polycarbonate polyol is used, improvement in discoloration resistance is required.

[0096] Therefore, from the viewpoint of discoloration resistance, by adjusting the lower limit of the amount of the phosphorus-based antioxidant depending on the amount of the polycarbonate polyol, discoloration resistance when the polycarbonate polyol is used is particularly significantly improved.

[0097] Specifically, from the viewpoint of discoloration resistance, the lower limit of the content of the phosphorus-based antioxidant is 0.02 parts by mass or more, preferably 0.022 parts by mass or more, more preferably 0.024 parts by mass or more, even more preferably 0.025 parts by mass or more, even more preferably 0.05 parts by mass or more, still more preferably 0.10 parts by mass or more, and particularly preferably 0.15 parts by mass or more, per 100 parts by mass of the polycarbonate polyol.

[0098] On the other hand, if the content of the phosphorus-based antioxidant is excessive relative to the polycarbonate polyol, the weather resistance of the thermoplastic polyurethane resin may be reduced. Therefore, from the viewpoint of weather resistance, the upper limit of the amount of the phosphorus-based antioxidant is adjusted according to the amount of the polycarbonate polyol.

[0099] Specifically, from the viewpoint of weather resistance, the upper limit of the content of the phosphorus-based antioxidant is 0.50 parts by mass or less, preferably 0.45 parts by mass or less, more preferably 0.40 parts by mass or less, even more preferably 0.35 parts by mass or less, even more preferably 0.30 parts by mass or less, still more preferably 0.25 parts by mass or less, and particularly preferably 0.20 parts by mass or less, per 100 parts by mass of polycarbonate polyol.

[0100] That is, from the viewpoint of excellent discoloration resistance and weather resistance, the content of the phosphorus-based antioxidant is 0.02 to 0.50 parts by mass, preferably 0.022 to 0.45 parts by mass, more preferably 0.024 to 0.40 parts by mass, even more preferably 0.025 to 0.35 parts by mass, still more preferably 0.05 to 0.30 parts by mass, still more preferably 0.10 to 0.25 parts by mass, and particularly preferably 0.15 to 0.20 parts by mass, relative to 100 parts by mass of the polycarbonate polyol.

[0101] As long as the content ratio of the phosphorus-based antioxidant to the polycarbonate polyol is within the above range, the content ratio (phr) of the phosphorus-based antioxidant to the total amount of the thermoplastic polyurethane resin (total amount of the polyisocyanate component and the polyol component) is not particularly limited.

[0102] (Phosphite ester antioxidant content) When the phosphorus-based antioxidant contains a phosphite ester-based antioxidant, from the viewpoint of discoloration resistance, the lower limit of the content of the phosphite ester-based antioxidant is, for example, 0.02 part by mass or more, preferably 0.022 part by mass or more, more preferably 0.024 part by mass or more, even more preferably 0.025 part by mass or more, still more preferably 0.05 part by mass or more, still more preferably 0.10 part by mass or more, and particularly preferably 0.15 part by mass or more, per 100 parts by mass of polycarbonate polyol.

[0103] Furthermore, from the viewpoint of weather resistance, the upper limit of the content of the phosphite ester-based antioxidant is, for example, 0.50 parts by mass or less, preferably 0.45 parts by mass or less, more preferably 0.40 parts by mass or less, even more preferably 0.35 parts by mass or less, even more preferably 0.30 parts by mass or less, still more preferably 0.25 parts by mass or less, and particularly preferably 0.20 parts by mass or less, per 100 parts by mass of polycarbonate polyol.

[0104] That is, from the viewpoint of excellent discoloration resistance and weather resistance, the content of the phosphite ester-based antioxidant is, for example, 0.02 to 0.50 parts by mass, preferably 0.022 to 0.45 parts by mass, more preferably 0.024 to 0.40 parts by mass, even more preferably 0.025 to 0.35 parts by mass, still more preferably 0.05 to 0.30 parts by mass, still more preferably 0.10 to 0.25 parts by mass, and particularly preferably 0.15 to 0.20 parts by mass, relative to 100 parts by mass of the polycarbonate polyol.

[0105] (Phosphate ester antioxidant content) When the phosphorus-based antioxidant contains a phosphate ester-based antioxidant, from the viewpoint of discoloration resistance, the lower limit of the content of the phosphate ester-based antioxidant is, for example, 0.02 part by mass or more, preferably 0.022 part by mass or more, more preferably 0.024 part by mass or more, even more preferably 0.025 part by mass or more, still more preferably 0.05 part by mass or more, still more preferably 0.10 part by mass or more, and particularly preferably 0.15 part by mass or more, per 100 parts by mass of the polycarbonate polyol.

[0106] Furthermore, from the viewpoint of weather resistance, the upper limit of the content of the phosphate ester-based antioxidant is, for example, 0.50 parts by mass or less, preferably 0.45 parts by mass or less, more preferably 0.40 parts by mass or less, even more preferably 0.35 parts by mass or less, even more preferably 0.30 parts by mass or less, still more preferably 0.25 parts by mass or less, and particularly preferably 0.20 parts by mass or less, per 100 parts by mass of polycarbonate polyol.

[0107] That is, from the viewpoint of excellent discoloration resistance and weather resistance, the content of the phosphate ester-based antioxidant is, for example, 0.02 to 0.50 parts by mass, preferably 0.022 to 0.45 parts by mass, more preferably 0.024 to 0.40 parts by mass, even more preferably 0.025 to 0.35 parts by mass, still more preferably 0.05 to 0.30 parts by mass, still more preferably 0.10 to 0.25 parts by mass, and particularly preferably 0.15 to 0.20 parts by mass, relative to 100 parts by mass of the polycarbonate polyol.

[0108] (Content of phosphorus compound antioxidant) When the phosphorus-based antioxidant contains a phosphorus compound-based antioxidant, from the viewpoint of discoloration resistance, the lower limit of the content of the phosphorus compound-based antioxidant is, for example, 0.02 parts by mass or more, preferably 0.022 parts by mass or more, more preferably 0.024 parts by mass or more, even more preferably 0.025 parts by mass or more, still more preferably 0.05 parts by mass or more, still more preferably 0.10 parts by mass or more, and particularly preferably 0.15 parts by mass or more, per 100 parts by mass of the polycarbonate polyol.

[0109] Furthermore, from the viewpoint of weather resistance, the upper limit of the content of the phosphorus compound-based antioxidant is, for example, 0.50 parts by mass or less, preferably 0.45 parts by mass or less, more preferably 0.40 parts by mass or less, even more preferably 0.35 parts by mass or less, even more preferably 0.30 parts by mass or less, still more preferably 0.25 parts by mass or less, and particularly preferably 0.20 parts by mass or less, per 100 parts by mass of polycarbonate polyol.

[0110] That is, from the viewpoint of excellent discoloration resistance and weather resistance, the content of the phosphorus compound-based antioxidant is, for example, 0.02 to 0.50 parts by mass, preferably 0.022 to 0.45 parts by mass, more preferably 0.024 to 0.40 parts by mass, even more preferably 0.025 to 0.35 parts by mass, still more preferably 0.05 to 0.30 parts by mass, still more preferably 0.10 to 0.25 parts by mass, and particularly preferably 0.15 to 0.20 parts by mass, relative to 100 parts by mass of the polycarbonate polyol.

[0111] [Other additives] The additive may contain other additives as optional components. The other additives are additives other than the phosphorus-based antioxidant.

[0112] Examples of other additives include other antioxidants (antioxidants other than phosphorus-based antioxidants), ultraviolet absorbers, light stabilizers, heat stabilizers, acidity regulators, hydrolysis inhibitors, dyes, plasticizers, antiblocking agents, surface modifiers, lubricants, mold release agents, pigments, fillers, rust inhibitors, and bulking agents. These may be used alone or in combination of two or more. The amount and timing of addition of the additives are appropriately determined depending on the purpose and application.

[0113] Preferable examples of the additives include other antioxidants (antioxidants excluding phosphorus-based antioxidants), ultraviolet absorbers, and light stabilizers.

[0114] (Other antioxidants (antioxidants excluding phosphorus-based antioxidants)) Examples of other antioxidants (antioxidants other than phosphorus-based antioxidants) include hindered phenol-based antioxidants. The other antioxidants preferably contain a hindered phenol-based antioxidant. In other words, the additive preferably further contains a hindered phenol-based antioxidant.

[0115] Examples of hindered phenol antioxidants include 2,6-t-butyl-p-cresol, n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetrakis(methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)methane, 4,4'-thiobis-(6-tert-butyl-3-methylphenol), 1,3,5-tris[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-1,3,5-triazine-2,4,6(1H ,3H,5H)-trione, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], N,N'-(hexane-1,6-diyl)-bis[4-hydroxy-3,5-bis(tert-butyl)benzenepropanamide], and benzenepropanoic acid 3,5-bis(1,1-dimethyl-ethyl)-4-hydroxy-branched alkyl (C7-9 alkyl) ester. These can be used alone or in combination of two or more. These are also commercially available.

[0116] The content of other antioxidants (antioxidants excluding phosphorus-based antioxidants) is not particularly limited and may be appropriately determined depending on the purpose and application.

[0117] (ultraviolet absorber) Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber. The ultraviolet absorber preferably contains a benzotriazole-based ultraviolet absorber. In other words, the additive preferably further contains a benzotriazole-based ultraviolet absorber.

[0118] Examples of benzotriazole-based ultraviolet absorbers include 4-methyl-2-(2H-benzotriazol-2-yl)phenol, 2,4-bis(α,α-dimethylbenzyl)-6-(2H-benzotriazol-2-yl)phenol, phenol, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methyl, and 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole. These can be used alone or in combination. These can also be commercially available.

[0119] In addition to the above, other examples of ultraviolet absorbers include 2-(2H-benzotriazol-2-yl)-4-methyl-6-dodecylphenol, bis[1,2,2,6,6-pentamethyl-4-piperidinyl]2-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylpropanedioate, 2-[4,6-bis(1,1'-biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol, and the reaction product of methyl 3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate with polyoxyethylene glycol. These may be used alone or in combination. These are also commercially available.

[0120] The content of the ultraviolet absorber is not particularly limited and may be appropriately determined depending on the purpose and application.

[0121] (light stabilizer) Examples of light stabilizers include hindered amine light stabilizers and benzophenone light stabilizers, which can be used alone or in combination of two or more.

[0122] As the light stabilizer, a hindered amine light stabilizer is preferably used. That is, the additive preferably further contains a hindered amine light stabilizer.

[0123] A hindered amine light stabilizer is a compound containing one or more hindered amine groups in one molecule.

[0124] More specifically, examples of the hindered amine light stabilizer include a hindered amine light stabilizer containing a single (one) hindered amine group in one molecule, and a hindered amine light stabilizer containing multiple (two or more) hindered amine groups in one molecule.

[0125] An example of a hindered amine light stabilizer containing a single hindered amine group per molecule is a reaction product of one molecule of butanedicarboxylic acid, one molecule of dimethyl ester, and one molecule of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol. Another example of a hindered amine light stabilizer containing a single hindered amine group per molecule is methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate. These may be used alone or in combination. These may also be commercially available.

[0126] Examples of hindered amine light stabilizers containing multiple (two or more) hindered amine groups in one molecule include hindered amine light stabilizers containing two hindered amine groups in one molecule and hindered amine light stabilizers containing three or more hindered amine groups in one molecule.

[0127] An example of a hindered amine light stabilizer containing two hindered amine groups per molecule is a copolymer of two molecules of butanedicarboxylic acid, two molecules of dimethyl ester, and two molecules of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol. Examples of hindered amine light stabilizers containing two hindered amine groups per molecule include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate and bis(1,2,2,6,6-pentamethyl-4-piperidylsebacate). These can be used alone or in combination of two or more. These are also commercially available.

[0128] Examples of hindered amine light stabilizers containing three or more hindered amine groups per molecule include copolymers of three or more molecules of butanedicarboxylic acid, three or more molecules of dimethyl ester, and three or more molecules of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol. Examples of hindered amine light stabilizers containing three or more hindered amine groups per molecule include the reaction product of 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol. Examples of hindered amine light stabilizers containing three or more hindered amine groups per molecule include 1,2,3,4-butanetetracarboxylic acid tetrakis(2,2,6,6-tetramethyl-4-piperidinyl). These stabilizers can be used alone or in combination. These stabilizers are also commercially available.

[0129] The hindered amine light stabilizer may contain one or more hindered phenol groups in addition to the hindered amine group. Examples of hindered amine light stabilizers containing a hindered phenol group include hindered amine light stabilizers containing two hindered amine groups and one hindered phenol group in one molecule, and more specifically, bis[1,2,2,6,6-pentamethyl-4-piperidinyl]2-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylpropanedioate.

[0130] The light stabilizer may be used alone or in combination of two or more kinds. From the viewpoint of weather resistance, the light stabilizer is preferably a hindered amine light stabilizer.

[0131] That is, when the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, the addition of a hindered amine-based light stabilizer provides even better weather resistance. Therefore, when the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, the light stabilizer preferably contains a hindered amine group.

[0132] Furthermore, from the viewpoint of weather resistance, the hindered amine light stabilizer preferably contains two or more hindered amine groups in one molecule. That is, preferred examples of the hindered amine light stabilizer include hindered amine light stabilizers containing multiple (two or more) hindered amine groups in one molecule.

[0133] When the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, particularly excellent weather resistance can be obtained if the hindered amine light stabilizer contains multiple (two or more) hindered amine groups in one molecule. Therefore, when the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, the hindered amine light stabilizer preferably contains multiple (two or more) hindered amine groups in one molecule.

[0134] Furthermore, from the viewpoint of weather resistance, among the above-mentioned hindered amine light stabilizers containing multiple (two or more) hindered amine groups in one molecule, preferred are hindered amine light stabilizers containing three or more hindered amine groups in one molecule and hindered amine light stabilizers containing two hindered amine groups and one hindered phenol group in one molecule.

[0135] That is, from the viewpoint of weather resistance, the hindered amine light stabilizer more preferably contains three or more hindered amine groups in one molecule, or two hindered amine groups and one or more hindered phenol groups in one molecule.

[0136] When the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, particularly excellent weather resistance can be obtained if the hindered amine light stabilizer contains three or more hindered amine groups per molecule. Furthermore, particularly excellent weather resistance can be obtained if the hindered amine light stabilizer contains two hindered amine groups and one hindered phenol group per molecule. Therefore, when the polyol component contains a polycarbonate polyol and the additive contains a phosphorus-based antioxidant, the hindered amine light stabilizer preferably contains three or more hindered amine groups per molecule, or two hindered amine groups and one or more hindered phenol groups per molecule.

[0137] A preferred example of such a hindered amine light stabilizer is bis[1,2,2,6,6-pentamethyl-4-piperidinyl]2-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylpropanedioate. A preferred example of the hindered amine light stabilizer is a reaction product of 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol. A preferred example of the hindered amine light stabilizer is a copolymer of three or more molecules of butanedicarboxylic acid, three or more molecules of dimethyl ester, and three or more molecules of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol.

[0138] In particular, from the viewpoint of weather resistance, among the above-mentioned hindered amine light stabilizers containing multiple (two or more) hindered amine groups in one molecule, particularly preferred are hindered amine light stabilizers containing two hindered amine groups and one hindered phenol group in one molecule.

[0139] That is, from the viewpoint of weather resistance, it is particularly preferable that the hindered amine light stabilizer contains two hindered amine groups and one or more hindered phenol groups in one molecule. That is, a particularly preferable example of the hindered amine light stabilizer is a hindered amine light stabilizer containing two hindered amine groups and one hindered phenol group in one molecule.

[0140] More specifically, a particularly preferred example of the hindered amine light stabilizer is bis[1,2,2,6,6-pentamethyl-4-piperidinyl]2-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylpropanedioate.

[0141] The content of the light stabilizer is not particularly limited and may be appropriately determined depending on the purpose and application.

[0142] (4) Method for producing thermoplastic polyurethane resin composition The thermoplastic polyurethane resin composition contains a thermoplastic polyurethane resin and an additive, as described above. The thermoplastic polyurethane resin is a reaction product of a polyisocyanate component and a polyol component, which are raw material components.

[0143] The method for producing a thermoplastic polyurethane resin composition is not particularly limited. For example, an additive is added to raw material components of a thermoplastic polyurethane resin. In such a case, a thermoplastic polyurethane resin is obtained by reaction of the raw material components containing the additive, and a thermoplastic polyurethane resin composition containing the additive and the thermoplastic polyurethane resin is also obtained.

[0144] More specifically, in this method, first, an additive is added to the raw material components of the thermoplastic polyurethane resin (addition step).

[0145] The raw material components of the thermoplastic polyurethane resin include the polyisocyanate component and the polyol component, preferably the polyol component. The polyol component includes, for example, the high-molecular-weight polyol and the low-molecular-weight polyol, preferably the high-molecular-weight polyol.

[0146] That is, in this method, the additive is preferably added to the high-molecular-weight polyol in the above-mentioned ratio to prepare a polyol composition containing the high-molecular-weight polyol and the additive.

[0147] Next, in this method, a thermoplastic polyurethane resin is produced by reacting a polyisocyanate component with a polyol component (including a polyol composition (the same applies hereinafter)) (reaction step).

[0148] In the reaction step, the polyisocyanate component and the polyol component can be reacted by a known method, such as a one-shot method or a prepolymer method.

[0149] In the one-shot method, for example, a polyisocyanate component and a polyol component are reacted at once. In the prepolymer method, for example, a polyisocyanate component is first reacted with a high-molecular-weight polyol to synthesize an isocyanate-terminated prepolymer. Then, the isocyanate-terminated prepolymer is reacted with a low-molecular-weight polyol. From the viewpoint of improving various physical properties, the prepolymer method is preferred.

[0150] In the prepolymer method, first, a polyisocyanate component is reacted with a high-molecular-weight polyol (preferably a polyol composition containing a high-molecular-weight polyol and an additive) to synthesize an isocyanate-terminated prepolymer (prepolymer synthesis step).

[0151] In the prepolymer synthesis step, a polyisocyanate component and a high-molecular-weight polyol (preferably a polyol composition containing a high-molecular-weight polyol and an additive) are mixed in a predetermined ratio, which is adjusted based on the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group in the polyisocyanate component to the hydroxyl group in the high-molecular-weight polyol.

[0152] That is, the equivalent ratio of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the high molecular weight polyol (isocyanate groups / hydroxyl groups) is, for example, 1.3 to 20, preferably 1.5 to 10, and more preferably 1.5 to 8.

[0153] In terms of mass, the amount of the polyisocyanate component per 100 parts by mass of the high-molecular-weight polyol is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and for example, 150 parts by mass or less, preferably 100 parts by mass or less, more preferably 90 parts by mass or less.

[0154] In the prepolymer synthesis step, the method for reacting the polyisocyanate component with the high-molecular-weight polyol is not particularly limited, and examples of the reaction method include bulk polymerization and solution polymerization.

[0155] In bulk polymerization, for example, a polyisocyanate component and a high-molecular-weight polyol are reacted under a nitrogen stream. The reaction temperature is, for example, 50°C or higher. The reaction temperature is, for example, 250°C or lower, preferably 200°C or lower. The reaction time is, for example, 0.5 hours or higher, preferably 1 hour or higher. The reaction time is, for example, 48 hours or lower, preferably 24 hours or lower.

[0156] In solution polymerization, a polyisocyanate component and a high-molecular-weight polyol are reacted in the presence of a known organic solvent. The reaction temperature is, for example, 50°C or higher. The reaction temperature is, for example, 120°C or lower, preferably 100°C or lower. The reaction time is, for example, 0.5 hours or higher, preferably 1 hour or higher. The reaction time is, for example, 48 hours or lower, preferably 24 hours or lower.

[0157] As a result, an isocyanate-terminated prepolymer is obtained as a reaction product liquid between the polyisocyanate component and the high-molecular-weight polyol. Also, an isocyanate-terminated prepolymer is obtained. As a result, a prepolymer composition containing the isocyanate-terminated prepolymer and the additive is obtained.

[0158] In the prepolymer synthesis step, a known urethanization catalyst may be added as needed. The amount of the urethanization catalyst added is appropriately determined depending on the purpose and application.

[0159] In the prepolymer synthesis step, the isocyanate-terminated prepolymer may be purified by a known method, such as distillation or extraction, if necessary.

[0160] Next, in this method, the isocyanate group-terminated prepolymer is reacted with a low-molecular-weight polyol to obtain a thermoplastic polyurethane resin (chain extension step).

[0161] In the chain extension step, an isocyanate-terminated prepolymer (preferably a prepolymer composition) and a low-molecular-weight polyol are mixed in a predetermined ratio, which is adjusted based on the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate groups in the isocyanate-terminated prepolymer to the hydroxyl groups in the low-molecular-weight polyol.

[0162] That is, the equivalent ratio of the isocyanate groups in the isocyanate-terminated prepolymer to the hydroxyl groups in the low-molecular-weight polyol (isocyanate groups / hydroxyl groups) is, for example, 0.75 or more, preferably 0.9 or more.Further, the equivalent ratio of the isocyanate groups in the isocyanate-terminated prepolymer to the hydroxyl groups in the low-molecular-weight polyol (isocyanate groups / hydroxyl groups) is, for example, 1.3 or less, preferably 1.1 or less.

[0163] In terms of mass, the amount of the low-molecular-weight polyol relative to 100 parts by mass of the isocyanate group-terminated prepolymer is, for example, 1.0 part by mass or more, preferably 2.5 parts by mass or more, more preferably 3.5 parts by mass or more, even more preferably 4.5 parts by mass or more, and particularly preferably 5.5 parts by mass or more, and for example, 15.0 parts by mass or less, preferably 10.0 parts by mass or less, more preferably 9.0 parts by mass or less.

[0164] In the chain extension step, the method for reacting the isocyanate-terminated prepolymer with the low-molecular-weight polyol is not particularly limited, and examples of the reaction method include the above-mentioned bulk polymerization and solution polymerization.

[0165] This produces a thermoplastic polyurethane resin as a reaction product of the isocyanate-terminated prepolymer and the low-molecular-weight polyol, resulting in a thermoplastic polyurethane resin composition containing the thermoplastic polyurethane resin and the additive.

[0166] In the chain extension step, a known urethanization catalyst may be added as needed. The amount of the urethanization catalyst added is appropriately determined depending on the purpose and application.

[0167] In this manner, a thermoplastic polyurethane resin composition containing a thermoplastic polyurethane resin and an additive is produced.

[0168] The method for producing a thermoplastic polyurethane resin composition is not limited to the above. In other words, in the above description, an additive is added to a high-molecular-weight polyol to prepare a polyol composition. Then, a prepolymer composition is prepared by mixing and reacting a polyisocyanate component with the polyol composition. Then, a thermoplastic polyurethane resin composition is produced by mixing and reacting the prepolymer composition with a low-molecular-weight polyol. Meanwhile, for example, the additive may be added to at least one selected from the group consisting of the polyisocyanate component, the high-molecular-weight polyol, and the low-molecular-weight polyol. That is, the additive may be added to the polyisocyanate component. Alternatively, the additive may be added to the low-molecular-weight polyol. Alternatively, the additive may be added to two or more of the polyisocyanate component, the high-molecular-weight polyol, and the low-molecular-weight polyol. Furthermore, the additive may be prepared separately from the polyisocyanate component, the high-molecular-weight polyol, and the low-molecular-weight polyol and then blended during mixing. For example, the additive may be added when the polyisocyanate component and the high-molecular-weight polyol are mixed, or when the isocyanate-terminated prepolymer and the low-molecular-weight polyol are mixed. In either of the above methods, a thermoplastic polyurethane resin composition containing a thermoplastic polyurethane resin and an additive is produced.

[0169] The thermoplastic polyurethane resin composition is subjected to an aging treatment as needed (aging step). In the aging step, the above-mentioned thermoplastic polyurethane resin composition (unaged product) is subjected to an aging treatment. This gives an aged product of the thermoplastic polyurethane resin composition.

[0170] The aging temperature is, for example, 50 to 100° C., preferably 60 to 90° C., and more preferably 70 to 90° C. The aging time is, for example, 1 to 10 days, preferably 3 to 9 days, more preferably 5 to 8 days, and still more preferably 6 to 8 days.

[0171] (5) Physical properties of thermoplastic polyurethane resin composition [Hard segment concentration] In the thermoplastic polyurethane resin composition, the hard segment concentration of the thermoplastic polyurethane resin is not particularly limited, but from the viewpoint of heat resistance, it is, for example, 18 to 35 mass%, preferably 20 to 30 mass%, and more preferably 22 to 25 mass%.

[0172] The concentration of the hard segment (the hard segment formed by the reaction of the polyisocyanate component with the low-molecular-weight polyol) of the thermoplastic polyurethane resin can be calculated by a known method, for example, from the blending ratio (charge) of each component.

[0173] More specifically, when a prepolymer method is used, the hard segment concentration can be calculated from the formulation (charge) of each component using the following formula:

[0174] [Low molecular weight polyol (g) + (Low molecular weight polyol (g) / Molecular weight of low molecular weight polyol (g / mol)) × Average molecular weight of polyisocyanate component (g / mol)] ÷ (Polyisocyanate component (g) + Total mass of polyol component (g)) × 100

[0175] (6) Effects The thermoplastic polyurethane resin composition contains a thermoplastic polyurethane resin and an additive. The thermoplastic polyurethane resin contains a reaction product of a polyisocyanate component and a polyol component, and the polyol component contains a polycarbonate polyol. The additive contains a phosphorus-based antioxidant. The content of the phosphorus-based antioxidant relative to the polycarbonate polyol is adjusted to a predetermined range.

[0176] More specifically, from the viewpoint of mechanical properties, the polyol component contains a polycarbonate polyol, which means that the thermoplastic polyurethane resin has excellent mechanical properties.

[0177] On the other hand, when polycarbonate polyol is used as a raw material for a thermoplastic polyurethane resin, a particular problem occurs in that the thermoplastic polyurethane resin may become discolored.

[0178] Therefore, the thermoplastic polyurethane resin composition contains a thermoplastic polyurethane resin and an additive, the additive contains a phosphorus-based antioxidant, and the proportion of the phosphorus-based antioxidant is a predetermined proportion or more, so that the thermoplastic polyurethane resin composition has excellent discoloration resistance.

[0179] However, if the proportion of the phosphorus-based antioxidant is excessive, this may cause a decrease in weather resistance, and even if the polyol component contains a polycarbonate polyol, the mechanical properties of the thermoplastic polyurethane resin composition may be reduced.

[0180] Therefore, in the thermoplastic polyurethane resin composition, the ratio of the phosphorus-based antioxidant is a predetermined ratio or less. As a result, the thermoplastic polyurethane resin composition has excellent weather resistance. In other words, the thermoplastic polyurethane resin composition has relatively excellent mechanical properties derived from the polycarbonate polyol even after weather resistance testing.

[0181] Therefore, the thermoplastic polyurethane resin composition can be suitably used in the production of various molded articles. That is, the thermoplastic polyurethane resin composition can be molded by a known molding method to obtain a molded article containing the thermoplastic polyurethane resin composition.

[0182] 2. Molded products and films The molded article containing the thermoplastic polyurethane resin composition is not particularly limited and can be produced by a known method.

[0183] Examples of molding methods include thermal compression molding, injection molding, extrusion molding, cut molding, melt spinning molding, and 3D printer molding. These can be used alone or in combination of two or more types.

[0184] A preferred molding method is extrusion molding. In extrusion molding, for example, the thermoplastic polyurethane resin composition is first subjected to primary molding to obtain pellets of the thermoplastic polyurethane resin composition. The pellets of the thermoplastic polyurethane resin composition are then subjected to secondary molding to obtain a molded product having a desired shape. In the primary molding and secondary molding, the above-mentioned additives may be added as necessary.

[0185] Examples of the shape of the molded product include film, sheet, plate, fiber, strand, pipe, hollow, and box shapes. These may be used alone or in combination of two or more. A preferred shape of the molded product is film.

[0186] In other words, the molded article is preferably a film containing the thermoplastic polyurethane resin composition.

[0187] The film contains the above-mentioned thermoplastic polyurethane resin composition, and therefore has excellent color resistance and weather resistance.

[0188] Therefore, the film can be suitably used in fields where the various physical properties described above are required. For example, the film can be suitably used as a base film for a paint protection film (PPF) for protecting the painted surfaces of various products in various industrial fields such as the automotive industry.

[0189] The protective film (PPF) is attached to the painted surface of various products (e.g., automobiles and motorcycles), thereby protecting the surface of the various products.

[0190] The protective film (PPF) comprises at least a film containing the thermoplastic polyurethane resin composition. More specifically, the protective film (PPF) comprises, for example, a release layer containing a polyester resin, an acrylic adhesive layer disposed on the release layer, and a base film layer disposed on the acrylic adhesive layer. The protective film (PPF) may further comprise a surface protective layer disposed on the base film layer.

[0191] For example, a film containing the thermoplastic polyurethane resin composition described above is used as the base film layer of a protective film (PPF). This provides the protective film (PPF) with excellent stretchability (recovery force), heat resistance, and finger print recovery. Therefore, the protective film (PPF) can provide excellent protection for various products (automobiles, motorcycles, etc.).

[0192] The thermoplastic polyurethane resins described above can be suitably used in various industrial fields where relatively excellent color resistance and weather resistance are required. [Example]

[0193] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited thereto. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, and parameters described in the above "Modes for Carrying Out the Invention."

[0194] 1.Raw materials (1) Polyisocyanate component (a) Manufacturing Example 1 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) was obtained in accordance with the description of Production Example 3 in International Publication WO2019 / 069802. The purity of the obtained 1,4-H6XDI measured by gas chromatography was 99.9%, the color of the obtained 1,4-H6XDI measured by APHA was 5, 13 The trans / cis ratio measured by C-NMR was 86 mol % trans isomer and 14 mol % cis isomer.

[0195] Meanwhile, commercially available 1,3-bis(isocyanatomethyl)cyclohexane (1,3-H6XDI, trade name Takenate 600, manufactured by Mitsui Chemicals, Inc.) was prepared.

[0196] In addition, a commercially available antioxidant (organic phosphorus compound, trade name JP-310, manufactured by Johoku Chemical Industry Co., Ltd.) was prepared as an additive.

[0197] Then, 22 parts by mass of 1,4-bis(isocyanatomethyl)cyclohexane, 9 parts by mass of 1,3-bis(isocyanatomethyl)cyclohexane, and 0.002 parts by mass (100 ppm) of an antioxidant (organic phosphorus compound, trade name JP-310, manufactured by Johoku Chemical Industry Co., Ltd.) were mixed together to obtain a polyisocyanate component.

[0198] The proportion of 1,4-bis(isocyanatomethyl)cyclohexane relative to the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane was 30 mol %.

[0199] (2) High molecular weight polyol (b) UH-100W: Product name, high molecular weight polyol, crystalline polycarbonate polyol, average number of hydroxyl groups: 2, number average molecular weight: 1000, manufactured by Ube Industries

[0200] (3) Low molecular weight polyol (c) 1,4-BD: 1,4-butanediol, manufactured by Mitsubishi Chemical Corporation

[0201] (4) Phosphorus-based antioxidants JPE-10: Trade name, phosphite ester antioxidant, bis(decyl)pentaerythritol diphosphite, manufactured by Johoku Chemical Industry Co., Ltd. JP-310: Trade name, phosphite ester antioxidant, tridecyl phosphite, manufactured by Johoku Chemical Industry Co., Ltd. JP-506H: Trade name, phosphate ester antioxidant, butoxyethyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd. JP-513: Trade name, phosphate ester antioxidant, isotridecyl acid phosphate, manufactured by Johoku Chemical Industry Co., Ltd. JC-263: Trade name, phosphorus compound antioxidant, triphenylphosphine, manufactured by Johoku Chemical Industry Co., Ltd.

[0202] (5) Light stabilizers Tin.PUR866: Product name: Tinuvin PUR866, bis[1,2,2,6,6-pentamethyl-4-piperidinyl] 2-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-2-butylpropanedioate, hindered amine group count: 2, hindered phenol group count: 1, BASF Japan LA-63P: Trade name: Adeka STAB LA-63P, reaction product of 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol, with 3 or more hindered amine groups and 0 hindered phenol groups, manufactured by ADEKA Tin.622SF: Product name: Tinuvin 622SF, a copolymer of one molecule of butanedicarboxylic acid, one molecule of dimethyl ester, and one molecule of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, with one hindered amine group and zero hindered phenol groups. BASF Japan

[0203] 2. Thermoplastic polyurethane resin composition and film Examples 1 to 21 and Comparative Examples 1 to 6 According to Tables 1 to 4, thermoplastic polyurethane resin compositions and films were obtained by the following methods.

[0204] More specifically, first, the macropolyol (b) whose temperature had been adjusted to 80°C was weighed. The macropolyol (b) was stirred in an oil bath at 80°C under a nitrogen atmosphere for 1 hour. Next,

[0205] Next, according to Tables 1 to 4, a phosphoric acid-based antioxidant and a light stabilizer were added to the high molecular weight polyol, and a commercially available hindered phenol-based antioxidant and a commercially available UV absorber were also added. These were then stirred at 700±50 rpm for 30 minutes in an 80°C oil bath using a high-speed stirring disper to obtain a mixture. In Comparative Examples 3 to 6, no phosphoric acid-based antioxidant was added.

[0206] Next, the polyisocyanate component (a) was added to the mixture of high molecular weight polyol (b) and additives in the proportions shown in Tables 1 to 4. Furthermore, a solution of stannous octoate (solvent: diisononyl adipate, concentration: 4% by mass) as a urethanization catalyst was added at a ratio of 5 ppm to the mixture. The mixture was then stirred and mixed in an 80°C oil bath for 5 minutes to allow the reaction to occur. This resulted in an isocyanate-terminated prepolymer (prepolymer synthesis step).

[0207] The amount of polyisocyanate component (a) added was adjusted so that the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group in polyisocyanate component (a) to the hydroxyl group in high molecular weight polyol (b) was 2.65. The tin octoate solution was added appropriately while monitoring the heat generation rate.

[0208] Next, the low-molecular-weight polyol (c) adjusted to a temperature of 80°C was added to the isocyanate-terminated prepolymer, and the mixture was stirred and mixed for 3 to 20 minutes.

[0209] The amount of low-molecular-weight polyol (c) added was adjusted so that the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group in the isocyanate-terminated prepolymer to the hydroxyl group in the low-molecular-weight polyol (c) was 1.01. The tin octoate solution was added appropriately while monitoring the heat generation rate.

[0210] The reaction product liquid was then poured into a Teflon (registered trademark) tray whose temperature had been adjusted to 150°C, and reacted at 150°C for 2 hours, and then further reacted at 100°C for 20 hours (chain extension step). This resulted in a thermoplastic polyurethane resin. Also, a thermoplastic polyurethane resin composition containing the thermoplastic polyurethane resin and additives was obtained.

[0211] Next, the thermoplastic polyurethane resin (unaged product) was taken out and cut into cubes using a bale cutter. The cube-shaped thermoplastic polyurethane resin was then pulverized using a pulverizer. This resulted in pulverized pellets.

[0212] The crushed pellets were then aged in an oven at 80° C. for 7 days and dried under reduced pressure in vacuum at 23° C. for 12 hours, thereby obtaining an aged thermoplastic polyurethane resin composition.

[0213] The aged thermoplastic polyurethane resin composition was then molded using a single-screw extruder (model: SZW40-28MG, manufactured by Technobel Co., Ltd.) to obtain pellets (primary molded product). The screw rotation speed of the extruder was 30 rpm, and the cylinder temperature was 150°C to 250°C. The pellets of the thermoplastic polyurethane resin composition were dried under reduced pressure in vacuum at 80°C for 12 hours.

[0214] The pellets were then molded using a single-screw extruder (model: SZW40-28MG, manufactured by Technobel Co., Ltd.) to obtain a film (secondary molded product) with a thickness of 150 μm. The screw rotation speed of the extruder was 20 rpm, and the cylinder temperature was 150° C. to 250° C. The film of the thermoplastic polyurethane resin composition was used in the following evaluation tests.

[0215] 3. Evaluation (1) Color resistance The discoloration resistance of the thermoplastic polyurethane resin composition was measured by the following method.

[0216] That is, the yellowness (b value) of the film (secondary molded product) having a thickness of 150 μm obtained by the above method immediately after production was measured using a color difference meter (Color Ace MODEL TC-1, manufactured by Tokyo Denshoku Co., Ltd.).

[0217] (2) Weather resistance The weather resistance of the film was measured as follows. Specifically, a test piece measuring 20 × 60 mm was cut out from a 150 μm thick film. Next, the test piece was irradiated with ultraviolet light using a QUV weathering tester (Ultraviolet Fluorescent Lamp Weather Meter FUV, manufactured by Suga Test Instruments Co., Ltd.) equipped with an ultraviolet fluorescent lamp. The ultraviolet light irradiation was repeated for a predetermined time (QUV 240 hours, 500 hours, and 740 hours), with one set consisting of irradiation (8 hours) and non-irradiation (4 hours) as shown below.

[0218] [irradiation] Temperature: 80℃ Relative humidity: 10% UV wavelength: 270~720nm Irradiation intensity: 28W / m 2 Duration: 8 hours

[0219] [Non-irradiation] Temperature: 50℃ Relative humidity: 95% Duration: 4 hours

[0220] Test pieces were then punched out using a JIS No. 4 dumbbell. The tensile strength (TS) of the test pieces after the UV irradiation test was measured using a tensile testing machine (Tensilon universal material testing machine RTG-1310, manufactured by A&D Co., Ltd.). The tensile strength (TS) of the test pieces before the UV irradiation test (QUV0 hours) was also measured.

[0221] The tensile strength (TS) was measured at a temperature of 23° C.±2° C., a pulling speed of 300 mm / min, and a chuck distance of 50 mm. The results are shown in Tables 1 to 4.

[0222]

Table 1

[0223]

Table 2

[0224]

Table 3

[0225]

Table 4

Claims

1. A thermoplastic polyurethane resin composition containing a thermoplastic polyurethane resin and an additive, The thermoplastic polyurethane resin contains a reaction product of a polyisocyanate component and a polyol component, the polyol component contains a polycarbonate polyol, The additive contains a phosphorus-based antioxidant, The thermoplastic polyurethane resin composition has a content of the phosphorus-based antioxidant of 0.02 to 0.50 parts by mass per 100 parts by mass of the polycarbonate polyol.

2. The thermoplastic polyurethane resin composition according to claim 1 , wherein the polycarbonate polyol contains a crystalline polycarbonate polyol.

3. The phosphorus-based antioxidant is 2. The thermoplastic polyurethane resin composition according to claim 1, further comprising at least one antioxidant selected from the group consisting of a phosphite ester-based antioxidant, a phosphate ester-based antioxidant, and a phosphorus compound-based antioxidant.

4. The thermoplastic polyurethane resin composition according to claim 1 , wherein the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane.

5. the polyisocyanate component contains 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane, 2. The thermoplastic polyurethane resin composition according to claim 1, wherein the content of 1,4-bis(isocyanatomethyl)cyclohexane is 50 mol% or more based on the total amount of 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane.

6. The thermoplastic polyurethane resin composition according to claim 1 , wherein the additive further comprises a hindered amine light stabilizer.

7. The hindered amine light stabilizer is The thermoplastic polyurethane resin composition according to claim 6, which contains two or more hindered amine groups in one molecule.

8. The hindered amine light stabilizer is Contains three or more hindered amine groups in one molecule, or The thermoplastic polyurethane resin composition according to claim 6, which contains two hindered amine groups and one or more hindered phenol groups in one molecule.

9. A film comprising the thermoplastic polyurethane resin composition according to any one of claims 1 to 8.

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