JP2019137789A - Thermoplastic polyurethane resin composition, and molding including the resin composition - Google Patents

Abstract

To provide a thermoplastic resin composition that can form an article having improved wear resistance, mechanical properties, hydrolysis resistance, transparency, and blooming resistance and required durability.SOLUTION: A thermoplastic polyurethane resin composition is a reaction product of an isocyanate component (A), a chain extender (B), and a polyol component (C). The isocyanate component (A) has an aliphatic polyisocyanate, The polyol component (C) has a polycarbonate polyol (C1), and a polyol (C2) having a cyclic structure. A mass ratio between the polycarbonate polyol (C1) and the polyol (C2) having the cyclic structure,(C1)/(C2), is 10/90 or more and 90/10 or less.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic polyurethane resin composition and a molded body using the resin composition.

Thermoplastic polyurethane resin (hereinafter referred to as TPU) is excellent in strength, flexibility, and wear resistance, and is therefore used as various members that require mechanical durability.
As TPU, TPU using aromatic isocyanate is generally used. However, TPU using aromatic isocyanate has a poor design due to yellowing over time. Therefore, TPU formed from aliphatic or alicyclic diisocyanate is frequently used when emphasizing design properties.

Patent Document 1 discloses a thermoplastic polyurethane elastomer mainly composed of a polymer diol containing an aromatic ring and an aliphatic diisocyanate.
Patent Document 2 discloses a polyurethane molding material composed mainly of a mixed polyol composed of a polycarbonate diol and a polyester diol starting from adipic acid; and 1,6-hexamethylene diisocyanate.
Patent Document 3 discloses a TPU using an aliphatic isocyanate, a polycarbonate polyol, and a diol having 6 or more carbon atoms as a chain extender.

JP-A-63-111011 Japanese Patent Application Laid-Open No. 6-209773 JP-A-6-116355

However, even a TPU formed from an alicyclic diisocyanate has insufficient wear resistance under a use environment in which a severe mechanical load is applied, and is insufficient for maintaining designability. Therefore, the TPU obtained from the polyurethane molding material according to Patent Document 2 and the TPU according to Patent Document 3 have insufficient wear resistance, and further improvement has been demanded.
In addition, the thermoplastic polyurethane elastomer according to Patent Document 1 lacks hydrolysis resistance because the polymer diol containing an aromatic ring in the molecule is a polyester polyol.

  As a result of intensive studies to solve the above problems, the present inventors are a reaction product of an aliphatic polyisocyanate and a polyol component, and the polyol component has a polycarbonate polyol and a cyclic structure. It has been found that a thermoplastic polyurethane resin containing a specific proportion of polyol exhibits higher wear resistance than when these polyols are used alone. As a result of further earnest studies on this specific TPU, various properties have been achieved at a high level, and a thermoplastic polyurethane resin composition that can be put to practical use and a molded product using the same have been completed. .

  Therefore, one embodiment of the present invention provides a thermoplastic polyurethane resin composition that has excellent mechanical properties, hydrolysis resistance, transparency, bloom resistance, wear resistance, and can suppress a decrease in durability over a long period of time. Is aimed at providing. In addition, another embodiment of the present invention is directed to providing a molded body made of the thermoplastic polyurethane resin composition.

The thermoplastic polyurethane resin composition according to one embodiment of the present invention is a thermoplastic polyurethane resin composition that is a reaction product of an isocyanate component (A), a chain extender (B), and a polyol component (C). Because
The isocyanate component (A) includes an aliphatic polyisocyanate,
The polyol component (C) is
Polycarbonate polyol (C1);
A polyol (C2) having a cyclic structure,
The mass ratio (C1) / (C2) of the polycarbonate polyol (C1) and the polyol (C2) having the cyclic structure is 10/90 or more and 90/10 or less.
Moreover, the molded object concerning other embodiment of this invention consists of said thermoplastic polyurethane resin composition.

  According to the thermoplastic polyurethane resin composition of one embodiment of the present invention, it has excellent mechanical properties, hydrolysis resistance, transparency, bloom resistance, and wear resistance, and suppresses deterioration in durability over a long period of time. A thermoplastic polyurethane resin composition can be provided. Moreover, according to the molded object concerning other embodiment of this invention, the molded object which consists of this thermoplastic polyurethane resin composition can be provided.

  Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail.

[Thermoplastic polyurethane resin composition]
The thermoplastic polyurethane resin composition according to one embodiment of the present invention is a thermoplastic polyurethane resin composition that is a reaction product of an isocyanate component (A), a chain extender (B), and a polyol component (C). Because
The isocyanate component (A) includes an aliphatic polyisocyanate,
The polyol component (C) is
Polycarbonate polyol (C1);
A polyol (C2) having a cyclic structure,
The mass ratio (C1) / (C2) of the polycarbonate polyol (C1) and the polyol (C2) having the cyclic structure is 10/90 or more and 90/10 or less.

<Isocyanate component (A)>
The isocyanate component (A) contains an aliphatic polyisocyanate. Examples of the aliphatic polyisocyanate include chain aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and trimethyl-hexamethylene diisocyanate; cyclohexane diisocyanate And alicyclic diisocyanates having an alicyclic structure such as dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and norbornane diisocyanate. In addition, the aliphatic polyisocyanate includes isocyanate group-terminated compounds by reaction of these isocyanates with active hydrogen group-containing compounds, or reactions of these compounds themselves, such as uretdioneization reaction, isocyanuration reaction, carbodiimidization reaction, etc. A polyisocyanate modified product by the above can also be used.
Among these isocyanates, 1,6-hexamethylene diisocyanate is preferable from the viewpoint of improving toughness and flexibility.

<Chain extender (B)>
Examples of the chain extender (B) include low molecular diols and bifunctional low molecular glycol ethers.

Examples of the low molecular diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-butanediol, Pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl- 2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol, 1,4-bis One or a mixture of two or more such as (2-hydroxyethoxy) benzene may be mentioned.
Moreover, as long as the properties of the thermoplastic resin are not impaired, 1-decanol, 1-dodecanol, stearyl alcohol, 1-docosanol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, etc. An active hydrogen compound having a functional group number of 1 or an active hydrogen compound having a functional group number greater than 2, such as glycerin, trimethylolpropane, pentaerythritol, diglycerin, sorbitol, or the like can be used in combination.

  Examples of the bifunctional low-molecular glycol ethers include 2,2-bis (4-polyoxyethylene-oxyphenyl) propane, 2,2-bis (4-polyoxypropylene-oxyphenyl) propane, and dimethylolheptane. Examples include ethylene oxide adducts and glycol ethers of dimethylol heptane propylene oxide adducts. Moreover, these 1 type (s) or 2 or more types can be used together.

The number average molecular weight of the chain extender (B) is preferably 60 or more and 300 or less in order to make use of flexibility and flexibility, which are inherent characteristics of the thermoplastic resin.
When the number average molecular weight of the chain extender (B) is less than 60, the urethane group concentration of the TPU becomes relatively high, so that an unmelted product is generated or the TPU melt is increased in viscosity. Occasionally, molding defects may occur, resulting in poor appearance. When the number average molecular weight is less than 60, the hardness, 100% modulus, tensile strength, and tear strength are increased, but the elongation is reduced, and the flexibility and flexibility, which are inherent properties of the thermoplastic resin, are reduced. It may be difficult to save.
On the other hand, when the number average molecular weight of the chain extender (B) exceeds 300, the urethane group concentration becomes relatively low, and the desired physical properties may not be obtained. A molded article of the thermoplastic polyurethane resin composition obtained using this TPU may have insufficient mechanical properties.

  Of these, the chain extender (B) is preferably at least one selected from the group consisting of 1,4-butanediol and 1,6-hexanediol.

<Polyol component (C)>
The polyol component (C) includes a polycarbonate polyol (C1) and a polyol (C2) having a cyclic structure.

<< Polycarbonate polyol (C1) >>
Examples of the polycarbonate polyol (C1) include 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, ethylene glycol, Diols including 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, and dimethyl Examples thereof include polycarbonate diols which can be obtained by dealcoholization reaction, dephenol reaction, etc. with carbonate, diethyl carbonate, diphenyl carbonate, diethylene carbonate and the like. Two or more kinds of polycarbonate diols can be used in combination.
Among these, polycarbonate diols are preferable from the viewpoint of improving durability such as hydrolysis resistance. In order to further improve the wear resistance, polycarbonate diols in which the reaction residue is composed only of a linear alkylene group are further preferred. That is, polycarbonate diols having no cyclic structure or branched alkyl group are more preferred.

<< Polyol having a cyclic structure (C2) >>
The polyol (C2) having a cyclic structure is a polyol having a cyclic structure such as an aromatic ring structure or an alicyclic structure in the molecule, and examples thereof include polyester diols, polycarbonate diols, polylactone diols, and polyether diols. 1 type, or 2 or more types can be used together. The polyol (C2) having a cyclic structure is preferably a polyether diol containing a structural unit derived from isophthalic acid.
Among these polyols, from the viewpoints of transparency, compatibility of bloom-causing substances such as cyclic oligomers and stabilizers contained as a by-product in TPU, hydrolysis resistance, and economical aspects, components derived from isophthalic acid, and 1 Polyester diols comprising a component derived from 1,6-hexanediol are particularly preferred.

<< Number average molecular weight of polyol component (C) >>
Further, the number average molecular weight of the polyol component (C) is preferably 750 or more and 3000 or less, more preferably 800 or more and 2000 or less, and still more preferably 1000 or more and 2000 or less.
When the number average molecular weight is 750 or more and 3000 or less, the moldability at the time of processing the thermoplastic polyurethane resin is improved, and the mechanical properties and transparency of the molded product of the resin composition can be further improved.
In addition, the number average molecular weight of the polyol component (C) is based on JIS K 7252-3 (Plastic-Determination of average molecular weight and molecular weight distribution of polymer by size exclusion chromatography-Part 3: Method near normal temperature) Can be measured.

<< mass ratio (C1) / (C2) >>
The mass ratio (C1) / (C2) of the polycarbonate polyol (C1) and the polyol (C2) having a cyclic structure is 10/90 or more and 90/10 or less, more preferably 30/70 or more and 70/30 or less. is there.
By mixing and using the polycarbonate polyol (C1) and the polyol (C2) having a cyclic structure, it is possible to develop wear resistance superior to the case where each polyol is used alone. However, when the mass ratio of the polycarbonate polyol (C1) or the polyol (C2) having a cyclic structure is less than 10/90, the wear resistance is insufficient and the appearance is deteriorated.

<< Other polyol components >>
In addition, as long as the gist of the present disclosure is not impaired, polylactone diols and polyether diols may be used in combination with the polycarbonate polyol (C1) and the polyol (C2) having a cyclic structure.

<< R 'value: number of moles of active hydrogen groups in chain extender (B) / number of moles of active hydrogen groups in polyol component (C) >>
The blending ratio of the chain extender (B) and the polyol component (C) is the ratio of the number of moles of active hydrogen groups in the chain extender (B) to the number of moles of active hydrogen groups in the polyol component (C) ([chain extender The number of moles of active hydrogen groups in (B) / [number of moles of active hydrogen groups in the polyol component (C)] = R ′ value) is an index of the hard segment amount of TPU and affects the expression of physical properties. From this viewpoint, the R ′ value is preferably 0.1 or more and 15 or less, and more preferably 0.3 or more and 12 or less.

<<< R value: total number of isocyanate group moles / total number of active hydrogen group moles >>>
The ratio of the total number of moles of isocyanate groups in the isocyanate component to the total number of moles of active hydrogen groups, which is the sum of the number of moles of active hydrogen groups in the chain extender (B) and the number of active hydrogen groups in the polyol component (C) ([total isocyanate The number of moles of groups] / [number of moles of all active hydrogen groups] = R value) is preferably 0.7 or more and 1.3 or less, more preferably from the viewpoint of adjusting the molecular weight or viscosity of TPU to a preferable range. 0.8 or more and 1.2 or less.

<Stabilizer>
The thermoplastic polyurethane resin composition may further contain at least one stabilizer selected from the group consisting of UV (Ultraviolet) absorbers, light stabilizers, and antioxidants.

  A conventionally well-known thing can be used as a UV absorber. As typical examples, for example, Tinuvin-328: 2- (2H-1,2,3-benzotriazol-2-yl) -4,6-di-tert-pentylphenol (manufactured by BASF), JF-83 : 2- [2-hydroxy-5- (1,1,3,3-tetramethylbutyl) phenyl] benzotriazole (manufactured by Johoku Chemical Industry Co., Ltd.), Tinuvin-326: 2- (2′-hydroxy-3′- t-butyl-5′-methylphenyl) -5-chlorobenzotriazole (manufactured by BASF), Adekastab LA-46: 2-ethylhexanoic acid = 2- [3-hydroxy-4- (4,6-diphenyl-1) , 3,5-triazin-2-yl) phenoxy] ethyl (manufactured by ADEKA), Tinuvin-1577: 2- (4,6-diphenyl-1,3,5-triazine 2-yl) -5- (hexyloxy) phenol (manufactured by BASF), Hostavin-VSU: N- (2-ethylphenyl) -N ′-(2-ethoxyphenyl) oxalic acid diamide (manufactured by Clariant), etc. Can be mentioned. These may be used alone or in combination of two or more.

  A conventionally well-known thing can be used as a light stabilizer. Representative examples include, for example, Chimassorb-944: poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2, 2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (manufactured by BASF), Tinuvin-622: dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (BASF), Tinuvin-770: bis (2,2,6,6-tetramethyl) Piperidin-4-yl) = decandioate (manufactured by BASF), Tinuvin-765: bis (1,2,2,6,6-pentamethyl-4-piperidyl) = decandioea Doo (BASF), and the like. These may be used alone or in combination of two or more.

  A conventionally well-known thing can be used as antioxidant. As typical examples, for example, IRGANOX-1010: pentaerythritol = tetrakis [3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] (manufactured by BASF), Sumilizer GA-80 : 2,2′-dimethyl-2,2 ′-(2,4,8,10-tetraoxaspiro [5.5] undecane-3,9-diyl) dipropane-1,1′-diyl = bis [3 -(3-tert-butyl-4-hydroxy-5-methylphenyl) propanoate] (manufactured by Sumitomo Chemical Co., Ltd.). These may be used alone or in combination of two or more.

<Other additives>
For the thermoplastic polyurethane resin composition, in addition to those described above, if necessary, a thermal stabilizer, an antioxidant, an ultraviolet absorber, a flame retardant, and a hydrolysis inhibitor that are usually used when producing TPU. , Heat resistance improver, weather resistance improver, reactive retarder, lubricant, plasticizer, antistatic agent, conductivity imparting agent, antibacterial agent, antifungal agent, colorant, inorganic and organic filler, fiber-based reinforcing material, Various additives such as a crystal nucleating agent can be appropriately added.

<Method for producing thermoplastic polyurethane resin composition>
The thermoplastic polyurethane resin composition is prepared by mixing raw materials (TPU, stabilizers, other additives) blended in an appropriate ratio with a kneader or Henschel mixer, etc., and then feeding to an extruder to extrude ordinary TPU. After melt-kneading at a temperature (about 150 ° C. or more and 220 ° C. or less), it can be prepared in a pellet shape by strand cutting or underwater cutting. In addition, since both a stabilizer and other additives are optional components, an appropriate amount of one or two or more selected from these may be added as needed during mixing.

  Moreover, after mixing arbitrary components with the raw material at the time of manufacturing the said TPU, for example, a polyol component (C) or an isocyanate component (A) and mixing it uniformly, it is made to react and prepares a thermoplastic polyurethane resin composition. You can also.

  As a method for adding an optional component such as a stabilizer, in addition to the method of adding directly to TPU, a master batch containing an optional component at a high concentration is prepared in advance, and the master batch is converted into a desired concentration. A method of mixing with TPU in such a manner can also be used.

  The TPU constituting the thermoplastic polyurethane resin composition can be obtained by a known TPU production method, for example, a one-shot method, a prepolymer method, a batch reaction method, a continuous reaction method, a kneader method, an extruder method, or the like. it can.

  And a thermoplastic polyurethane resin composition is individually obtained as shapes, such as a flake, a pellet, powder, a granule, a rod, a sheet | seat, a block, by the said manufacturing method.

  Furthermore, the powdery or block-like solid obtained as described above is pulverized to obtain a flaky product, which is supplied to an extruder to extrude ordinary TPU (about 150 ° C. or higher). After melt-kneading at 220 ° C. or lower), a pellet-shaped product can be obtained by strand cutting or underwater cutting.

  In the kneader method, the kneader is charged with the polyol component (C), the chain extender (B), and optional components such as a stabilizer, heated to 100 ° C. with stirring, and then the isocyanate component (A). Is added, reacted for 10 to 120 minutes, and cooled to produce a powdery or block-shaped thermoplastic polyurethane resin composition. In these methods, a catalyst can be added as necessary.

<< Catalyst >>
Examples of the catalyst used in the production of the TPU include triethylamine, triethylenediamine, N-methylimidazole, N-ethylmorpholine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU; diazabicyclo undecene). Amines such as potassium acetate, stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, titanate ester, zirconium compound, bismuth compound, iron compound, etc .; tributylphosphine, phosphorene, phosphorene And phosphorus compounds such as oxides. These compounds can be used alone or in combination of two or more.
Of these, organic metals, particularly titanic acid esters, iron, tin, zirconium, and bismuth compounds are preferred. The total amount of the catalyst used is preferably about 5% by mass or less, more preferably 0.001% by mass to 2% by mass with respect to TPU.

  As a molding method of the thermoplastic polyurethane resin composition, a commonly used TPU molding method can be applied. For example, extrusion molding, injection molding, inflation molding, blow molding, vacuum molding, centrifugal molding, rotational molding, calendering, Forming methods such as roll processing and press processing can be used.

[Molded body]
The thermoplastic polyurethane resin composition described above can be suitably used as various molded articles. Therefore, the molded object concerning one Embodiment of this invention consists of a thermoplastic polyurethane resin composition mentioned above.
Examples of the molded body include interior / exterior materials for houses, communication cables, industrial cables, automobiles, various vehicle interior / exterior materials, household appliances, ornaments, wind turbines for wind power generation, protective films, and the like. These can be used in a wide range of indoor and outdoor fields.

[1]: The thermoplastic polyurethane resin composition according to the first embodiment of the present invention is a reaction product of an isocyanate component (A), a chain extender (B), and a polyol component (C). A thermoplastic polyurethane resin composition comprising:
The isocyanate component (A) includes an aliphatic polyisocyanate,
The polyol component (C) is
Polycarbonate polyol (C1);
A polyol (C2) having a cyclic structure,
The mass ratio (C1) / (C2) of the polycarbonate polyol (C1) and the polyol (C2) having the cyclic structure is 10/90 or more and 90/10 or less.
[2]: In the thermoplastic polyurethane resin composition according to the second embodiment of the present invention, the mass ratio (C1) / (C2) is 30/70 or more and 70/30 or less. The thermoplastic polyurethane resin composition described in 1.
[3]: The thermoplastic polyurethane resin composition according to the third embodiment of the present invention is described in the first or second embodiment, in which the aliphatic polyisocyanate is 1,6-hexamethylene diisocyanate. Thermoplastic polyurethane resin composition.
[4]: In the thermoplastic polyurethane resin composition according to the fourth embodiment of the present invention, the chain extender (B) is selected from the group consisting of 1,4-butanediol and 1,6-hexanediol. The thermoplastic polyurethane resin composition according to any one of the first to third aspects, which is at least one kind.
[5]: In the thermoplastic polyurethane resin composition according to the fifth embodiment of the present invention, any one of the first to fourth items is characterized in that the polycarbonate polyol (C1) is a polycarbonate diol. The thermoplastic polyurethane resin composition described.
[6]: The thermoplastic polyurethane resin composition according to the sixth embodiment of the present invention is characterized in that the polyol (C2) having the cyclic structure is a polyester diol containing a structural unit derived from isophthalic acid. The thermoplastic polyurethane resin composition according to any one of Items 1 to 5.
[7]: The thermoplastic polyurethane resin composition according to the seventh embodiment of the present invention is characterized in that the polycarbonate polyol (C1) is a polycarbonate diol in which a reaction residue consists of only a linear alkylene group. The thermoplastic polyurethane resin composition according to any one of 1 to 6.
[8]: The thermoplastic polyurethane resin composition according to the eighth embodiment of the present invention further includes at least one stabilizer selected from the group consisting of a UV absorber, a light stabilizer, and an antioxidant. The thermoplastic polyurethane resin composition according to any one of Items 1 to 7, which is characterized by the following.
[9]: A molded body according to the ninth embodiment of the present invention is composed of the thermoplastic polyurethane resin composition according to any one of the first to eighth aspects.

  According to the thermoplastic polyurethane resin composition according to one embodiment of the present invention, the wear resistance of the aliphatic TPU having high durability against yellowing with time is improved, and further, better mechanical properties by specifying the TPU composition, By achieving hydrolysis resistance and appearance, it is possible to achieve both design and durability.

  The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto.

<Examples 1-12, Comparative Examples 1-5>
(Sample preparation)
In a reaction vessel equipped with a stirrer and a thermometer, the polyol component (C) and the chain extender (B) are charged in the amounts (parts by mass) listed in Tables 1 to 3 and mixed uniformly. Obtained.
After heating the obtained liquid mixture at 100 degreeC, the isocyanate component (A) of the quantity (mass part) of Table 1-Table 3 was added, and the urethanation reaction was performed. When the reaction product reached 90 ° C., it was poured onto a vat and solidified to obtain a solid. The obtained solid was aged in an electric furnace at 80 ° C. for 16 hours and cooled to room temperature, and then the solid was pulverized to obtain a flaky TPU.
The obtained flake-shaped TPU is pelletized with an extruder, and the obtained pellet is subjected to T-die extrusion molding or injection molding at 180 to 220 ° C. to give a film having a thickness of 0.15 mm (extrusion molding) and a thickness of 2 mm. Sheet (injection molding) was prepared and used as samples (thermoplastic polyurethane resin compositions) of Examples 1 to 12 and Comparative Examples 1 to 5.

The raw materials used in Tables 1 to 3 are as follows.
<Isocyanate component (A)>
HDI: 1,6-hexamethylene diisocyanate, manufactured by Tosoh Corporation <Chain extender (B)>
1,4-BG: 1,4-butanediol (number average molecular weight = 90), manufactured by Mitsubishi Chemical Corporation 1,6-HG: 1,6-hexanediol (number average molecular weight = 118), manufactured by Mitsubishi Chemical Corporation <Polycarbonate diol (C1) whose reaction residue consists only of a linear alkyl group>
PCD (HG / MPD = 10/0) -1000: Polyhexamethylene carbonate diol (number average molecular weight = 1000), manufactured by Tosoh Corporation <Polycarbonate diol (C1) containing an alkyl group whose reaction residue has a side chain>
PCD (HG / MPD = 1/9) -1000: polycarbonate diol (number average molecular weight = 1000) having a molar ratio of hexamethylene residue and 3-methyl-pentamethylene residue of 1/9, manufactured by Tosoh Corporation <Polyol (C2) having a cyclic structure>
IPA / HG-1000: polyester diol (number average molecular weight = 1000) containing a structural unit derived from isophthalic acid and a structural unit derived from 1,6-hexanediol, manufactured by Tosoh Corporation <polyester diol>
BA-1000: Polyester diol (number average molecular weight = 1000) containing a structural unit derived from adipic acid and a structural unit derived from 1,4-butanediol, manufactured by Tosoh Corporation

(Characteristic test)
Various characteristics shown below were evaluated for the T-die extruded film or injection-molded sheet as a molded product produced by the above procedure. The obtained results are shown in Tables 1 to 3.

(1) Physical properties (mechanical properties)
Using a T-die extruded film, measurement was performed according to the measurement method described in JIS K 7311 (Testing method for polyurethane-based thermoplastic elastomer). An injection molded sheet was used for the hardness measurement and the Taber abrasion amount measurement.
[Hardness (JIS-A hardness)]
It can be said that 56 or more is sufficient.
[100% modulus (tensile stress, MPa)]
It can be said that 3.0 MPa or more is sufficient.
[Tensile strength (MPa)]
It can be said that 12 MPa or more is sufficient.
[Elongation (%)]
It can be said that 400% or more is sufficient.
[Tear strength (kN / m)]
60 kN / m or more is sufficient.
[Taber wear amount (mg)]
Less than 130 mg is sufficient, and less than 50 mg is good. For this reason, a sample of 130 mg or more was designated as D, a sample of less than 130 mg and 50 mg or more was designated as B, and a sample of less than 50 mg was designated as A.

(2) Transparency T-die extrusion film (thickness 0.15 mm) was used as a test piece, and haze was measured. A sample having a haze of less than 3% was designated as A, and a sample having a haze of 3% or more was designated as D. Haze was measured using a haze meter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

(3) Bloom resistance T-die extruded film (thickness 0.15 mm) was used as a test piece, and the change in haze was measured after immersion in pure water at 45 ° C. for 2 days. A change in haze ("Haze% after test"-"Haze% before test") less than 4% is A, 4% or more and less than 6% is B, and 6% or more is D. . Haze was measured by the same measurement method as in the transparency evaluation.

(4) Hydrolysis resistance Using a T-die extruded film (thickness 0.15 mm), punched into a dumbbell shape (No. 3) defined in JIS K7311 (Testing method for polyurethane-based thermoplastic elastomer), and a test piece It was. The test piece was immersed in warm water of 85 ° C. for 21 days, and the tensile strength was measured using a tensile tester (UTA-500, manufactured by Orientec Corp.). Compared with the physical properties (tensile strength) of the film before the test, the hydrolysis resistance was evaluated according to the retention rate according to the following criteria. A retention rate of 60% or more was designated as A, and retention rate less than 60% was designated as D.

Claims (9)

A thermoplastic polyurethane resin composition that is a reaction product of an isocyanate component (A), a chain extender (B), and a polyol component (C),
The isocyanate component (A) includes an aliphatic polyisocyanate,
The polyol component (C) is
Polycarbonate polyol (C1);
A polyol (C2) having a cyclic structure,
A thermoplastic polyurethane resin, wherein a mass ratio (C1) / (C2) of the polycarbonate polyol (C1) and the polyol (C2) having the cyclic structure is 10/90 or more and 90/10 or less. Composition.   The thermoplastic polyurethane resin composition according to claim 1, wherein the mass ratio (C1) / (C2) is 30/70 or more and 70/30 or less.   The thermoplastic polyurethane resin composition according to claim 1 or 2, wherein the aliphatic polyisocyanate is 1,6-hexamethylene diisocyanate.   The chain extender (B) is at least one selected from the group consisting of 1,4-butanediol and 1,6-hexanediol. The thermoplastic polyurethane resin composition according to Item.   The thermoplastic polyurethane resin composition according to any one of claims 1 to 4, wherein the polycarbonate polyol (C1) is a polycarbonate diol.   The thermoplastic polyurethane resin composition according to any one of claims 1 to 5, wherein the polyol (C2) having a cyclic structure is a polyester diol containing a structural unit derived from isophthalic acid.   The thermoplastic polyurethane resin composition according to any one of claims 1 to 6, wherein the polycarbonate polyol (C1) is a polycarbonate diol having a reaction residue consisting of only a linear alkylene group.   The thermoplastic polyurethane resin composition according to any one of claims 1 to 7, further comprising at least one stabilizer selected from the group consisting of UV absorbers, light stabilizers, and antioxidants. object.   The molded object which consists of a thermoplastic polyurethane resin composition of any one of Claims 1 thru | or 8.