JPH0362850A - Thermoplastic polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent injection moldability, water resistance, cold resistance and mechanical properties, etc., by mixing a specific thermoplastic polyurethane with a small amount of thermoplastic resin containing aromatic vinyl compound and vinyl cyanide compound as essential ingredients. CONSTITUTION:A1: Polyester diol having 1500-3500 number-averaged mol.wt.- containing units derived from diol expressed by formula I and/or formula II in a molar ratio of formula I: formula II=(100:0)-(50:50) and units derived from dicarboxylic acid expressed by formula III and/or formula IV ((n) is 4-12; Ar is 6-12C bifunctional aromatic hydrocarbon group) in a molar ratio of formula III: formula IV=(80:20)-(35:65) as essential ingredients is mixed with A2: diisocyanate and A3: chain extender in an amount of 13-40wt.% A2+A3 to total weight of A1+A2+A3 to obtain a thermoplastic polyurethane (A). Then, 92-99wt.% said composition (A) is mixed with (B) 8-1wt.% thermoplastic resin containing aromatic vinyl compound and vinyl cyanide compound as essential ingredients to afford the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a composition comprising a specific thermoplastic polyurethane blended with a small amount of a thermoplastic resin. The composition provided by the present invention has excellent injection moldability, as well as excellent water resistance, cold resistance, mechanical performance, and the like.

[Conventional technology]

Conventionally, thermoplastic polyurethane has many features such as high elastic modulus and excellent abrasion resistance and oil resistance, so it is attracting attention as an alternative material to rubber and plastic. It has come to be used in large quantities in a wide range of applications as an applicable molding material. Thermoplastic polyurethanes are produced by mixing and polymerizing polymeric diols, diisocyanates, and chain extenders such as 1,4-butanediol.

As thermoplastic polyurethanes, polyester polyurethanes, polyether polyurethanes, and polycarbonate polyurethanes are known, and each is used for various purposes by taking advantage of its characteristics. Among these, polyester polyurethane has excellent mechanical performance, but is known to have poor water resistance.

Mold release properties (prevention of stickiness) during molding of thermoplastic polyurethane
Proposal 3-Proposal: For the purpose of improving the molding shrinkage rate and reducing the molding shrinkage rate, a maximum of 99 to 50 weights of thermoplastic polyshale and a maximum of 1 to 50 weights of an acrylonitrile-styrene copolymer or blend polymer are blended. Thermoplastic polyurethane 90 has been developed (see Japanese Patent Publication No. 46-659) for the purpose of improving the mold releasability (prevention of stickiness) during molding of thermoplastic polyurethane and reducing the temperature dependence of melt viscosity. Attempts have been made to blend ethylene-propylene rubber with a maximum weight of 10 to 90% by weight of a resin obtained by graft polymerizing an aromatic vinyl compound and a vinyl cyanide compound (Japanese Patent Publication No. 60-17
(See Japanese Patent Publication No. 281 and Japanese Patent Publication No. 62-34265).

In addition, in order to improve the molding processability of thermoplastic polyurethane, 99 to 70 parts by weight of thermoplastic polyurethane is blended with 1 to 30 parts by weight of acrylonitrile-styrene-butadiene terpolymer or tertiary blend polymer. It has been proposed (see Japanese Patent Publication No. 54-7827).

[Problem to be solved by the invention]

Conventional thermoplastic polyurethanes have problems in injection moldability, such as long injection molding cycle times, poor productivity, and generation of sink marks.1 Improvements in these problems are strongly desired.

4 The thermoplastic polyurethane composition containing a resin obtained by graft polymerizing an aromatic vinyl compound and a vinyl cyanide compound to the above-mentioned ethylene-propylene rubber contains a large amount of graft polymer. Although the adhesion of thermoplastic polyurethane is improved, there are problems in that the original characteristics of thermoplastic polyurethane such as increased hardness, decreased elongation, and decreased bending resistance are lost. Also,
Thermoplastic polyurethane compositions containing an acrylonitrile-styrene copolymer or friend polymer and thermoplastic polyurethane compositions containing an acrylonitrile-styrene-butadiene terpolymer or terpolymer blend polymer are The reality is that the molding processability has not been improved to a satisfactory level 1 without any problems.

An object of the present invention is to provide a thermoplastic polyurethane composition that is excellent in water resistance, cold resistance, mechanical performance, etc., and also has excellent injection moldability.

[Means to solve the problem]

According to the present invention, the above objects are achieved by: (4) thermoplastic bow 5;
- The thermoplastic polyurethane is composed of (a) 92 to 99 polyurethanes and (B) 8 to 1 times more thermoplastic resin containing an aromatic vinyl compound and a vinyl cyanide compound as essential constituents; Average molecular weight 1.500-3
, 500 and (b) a diisocyanate and (c) a chain extender, and component (b)
) and (c) are in the range of 3 to 40% of the sum of the weights of components (a), (b) and (c),
The polyester diol contains the following structural units (I) and/or (II) as essential structural units derived from diols.
It has the following structural units (I[l) and (IV) as essential structural units derived from dicarboxylic acid, and the mole fraction of structural unit (I) and the mole of structural unit (U) The ratio of the fractions is in the range of Zoo to O to 50 to 50, and the ratio of the mole fraction of the structural unit (Iff) to the mole fraction of the structural unit (IV) is in the range of 8 to 20 to 35 to 65. This is achieved by providing a thermoplastic polyurethane composition characterized in that:

(I)' O+CH2+fO- 6- (n): CHa -O-CH2-CH+CH++i; O-OO 1]1] (I[I): -C+CH2+fO- (in the formula, n is 4
represents an integer of ~12, Ar represents a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ) In order for the composition of the present invention to exhibit high properties such as a high injection molding cycle speed, a small molding strain rate, and excellent mechanical performance, water resistance, and cold resistance, it is necessary to use thermoplastic polyurethane. It is important to have the structure specified above. In the case of a thermoplastic polyurethane composition that does not have this specified structure, the effect exhibited by the composition of the present invention is hardly observed.

It is extremely important that the polyester diol constituting the thermoplastic polyurethane in the present invention has a number average molecular weight in the range of 1,500 to 3,500, determined from the hydroxyl value and acid value. It is particularly preferable that the prestrain is in the range of 1,800 to 3,000. When the number average molecular weight is less than 1,500, there is almost no improvement in the injection molding cycle speed and molding strain rate, and when it exceeds 3,500, the change in melt viscosity during molding is severe and stable. It becomes difficult to mold the product.

The polyester diol has the above structural units (I) and/or (n) as essential structural units derived from diol, and the above structural units (III) and (IV) as essential structural units derived from dicarboxylic acid. has.

As a representative compound giving structural unit (I), 1゜9-
Examples include nonanediol, and 2-methyl-1,8-octanediol is a typical compound providing structural unit (II). The larger the proportion of structural units (I) and /''!, or (II) in the diol-derived structural units, the more a composition that exhibits the above-mentioned excellent properties can be obtained.Structural units (I) and /″! Taha (n)
The proportion of the diol-derived structural units is preferably on a 30-weight plate, and more preferably on a 50-weight plate. Structural units derived from diol are structural units (I) and/or
It is especially preferable to use only the case (II).

The ratio of the mole fraction of structural unit (I) to the mole fraction of structural unit (II) ranges from 100:0 to 50:50.

When the mole fraction of structural unit (II) is greater than the mole fraction of structural unit (I), the heat resistance and cold resistance of the composition are poor. Examples of diols used in conjunction with the production of polyester diol in the present invention include ethylene glycol, propylene gelicol, 1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, Examples include 3-methyl-1,5-bentanediol, 1,6-hexanediol, and 1,10-decanediol. These diols can be used alone or in twos.
Used in mixtures of more than one species.

Examples of the aliphatic dicarboxylic acid that provides the structural unit (II[) include adipic acid, azelaic acid, sebacic acid, and totecanniic acid, with adipic acid and azelaic acid being preferred. These aliphatic dicarboxylic acids may be used alone or in a mixture of two or more. Specifically, the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by Ar in the structural unit (IV) is a phenylene group or a naphthylene group. Examples of the aromatic dicarboxylic acid providing the structural unit (IV) include terephthalic acid, inphthalic acid, orthophthalic acid, 1°5-naphthalenedicarboxylic acid, 2. s-naphthalene dicarboxylic acid, 2.6
Examples include naphthalenedicarboxylic acid, and isophthalic acid and terephthalic acid are preferred. These aromatic dicarboxylic acids may be used alone or in a mixture of two or more. Molar fraction of structural unit (In) and structural unit (IV)
The ratio of mole fractions ranges from 80:20 to 35:65. The molar fraction of the structural unit (III) is this and the structural unit (I
Compositions obtained from polyester diols in which the sum of the mole fractions of V) exceeds 80 do not exhibit the above-mentioned excellent properties of the present invention. However, if the molar fraction of the structural unit (IV) is more than 6596% of the sum of this and the molar fraction of the structural unit (III), the injection moldability and cold resistance of the composition decrease. .

The polyester diol in the present invention can be produced by a method similar to the known method used in the production of polyethylene terephthalate or polybutylene terephthalate, for example, a transesterification reaction or a direct esterification reaction followed by a melt polycondensation reaction. be done.

In the thermoplastic polyurethane of the present invention, the sum of the weights of components (b) and (c), that is, the weight of the hard segment component is 13 to 40q6 relative to the sum of the weights of components (a), (b), and (c). It is important that the If the weight of the hard segment component is less than 13%, the effect of improving the injection moldability of the composition is small;
If it exceeds 40%, the melt viscosity of the composition will change significantly over time, resulting in poor moldability.

The thermoplastic polyurethane according to the present invention is obtained by melt polymerizing a polyester diol, a diisocyanate, and a chain extender. The diisocyanate used is an aliphatic, alicyclic or aromatic diisocyanate containing two incyanate groups in the molecule, such as 4,4-diphenylmethane diisocyanate, p-phenylene diisocyanate. Isocyanate, tolylene diisocyanate, 15-naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate, 4-. Examples include 4-dicyclohexylmethane diisocyanate. As the diisocyanate, 4,4-diphenylmethane diisocyanate is particularly preferred. Further, as the chain extender, a commonly used chain grower in the polyurethane industry, that is, a low molecular weight compound having a molecular weight of 400 or less and containing at least two hydrogen atoms capable of reacting with incyanate, such as ethylene glycol, propylene glycol, ，
4-butanediol, neopentyl glycol, 3-methyl-1,5-bentanediol, 1°6-hexanediol, 1,4-cyclohexanediol, xylylene glycol, 1,4-bis(β-hydroxyethoxy)benzene, Polyols such as bis(β-hydroxyethyl) terephthalate, trimethylolpropane, glycerin; ethylenediamine, propylene diamine, xylylene diamine, 4,4-diaminodiphenylmethane, 3,3
Diamines such as -dichloro-44-diaminodiphenylmethane, inphoron cyan, piperazine, phenylene cyan, and tolylene diamine; hydrazine; hydrazides such as adipic acid dihydrazide and inphthalic acid dihydrazide;

As a chain extender, 1,4-butanediol''! or 14
Most preferably, -bis(β-hydroxyethoxy)benzene is used. These compounds may be used alone or in combination of two or more. The polymerization conditions are those employed in known urethane production reactions, but the polymerization temperature is preferably in the range of 200 to 240°C. By keeping the polymerization temperature at 200°C or higher, a polyurethane with good moldability can be obtained, and by keeping the polymerization temperature at 240°C or lower, a polyurethane with increased heat resistance can be obtained. As the polymerization method, it is particularly preferable to employ a continuous melt polymerization method using a multi-screw extruder.

3 In the composition of the present invention, a thermoplastic resin containing an aromatic beer compound and a vinyl cyanide compound as essential constituents may be blended in a specific ratio with the thermoplastic polyurethane having the above-specified structure. This is an important requirement for achieving the above object of the present invention. In the present invention, it is necessary to mix a maximum of 92 to 99 weights of thermoplastic polysauce and a maximum of 8 to 1 weight of the above-mentioned thermoplastic resin. If the blending ratio of the thermoplastic resin is less than the maximum of 1 layer, the effect of the present invention will hardly be exhibited, and if it exceeds the maximum of 8 layers, the hardness of the composition will increase and the elongation will decrease. . Therefore, when comparing a composition having an increased hardness with a thermoplastic resin content of more than 8% by weight and a composition of the present invention having the same hardness, the former composition has a hardness of polyurethane. If the segment content is lower than that of the latter composition, no improvement in injection moldability is observed compared to the latter composition, and the bending resistance is also reduced, and the original characteristics of thermoplastic polyurethane are impaired. , its use will be limited.

14- In the present invention, the thermoplastic resin containing an aromatic vinyl compound and a vinyl cyanide compound as essential constituents may be, for example, a copolymer or blend polymer (hereinafter referred to as , this is abbreviated as As resin), an elastomer (graft base) containing an aromatic vinyl compound and a vinyl cyanide compound (
Examples include thermoplastic graft polymers obtained by graft polymerization of graft monomers). Examples of aromatic vinyl compounds include styrene, α-methylstyrene,
Nuclear alkyl-substituted styrene, nuclear halogen-substituted styrene, etc. are used. It is particularly preferred to use styrene.

Additionally, as the vinyl cyanide compound, for example, acrylonitrile, methacrylonitrile, etc. are used. Particular preference is given to using acrylonitrile. As the elastomer for the above-mentioned graft base, it is preferable to use one having a second-order transition temperature lower than -30°C.

Typical examples of As resins include copolymers obtained by emulsion polymerization of styrene and acrylonitrile, and blend polymers obtained by blending styrene homopolymers and acrylonitrile homopolymers. A copolymer is suitable as the As resin. The proportion of the aromatic vinyl compound and vinyl cyanide compound to be used is not particularly limited, but it is preferable that the former be used in a maximum amount of 60 to 90% by weight, and the latter be used as a maximum amount of 40 to 10% by weight.

Examples of thermoplastic graft polymers include resins obtained by graft polymerizing ethylene-propylene rubber with aromatic vinyl compounds and vinyl cyanide compounds (hereinafter referred to as ABS resins). As the ethylene-propylene comb, ethylene-propylene copolymer rubber and ethylene-propylene-diene copolymer rubber are used. The weight ratio of ethylene and propylene is 9:l
A range of ~2:8 is preferable! Yes. Examples of the cleaved diene monomers used include norbornenes such as alkenylnorbornene, cyclic dienes such as dicyclopentadiene, and aliphatic dienes such as hexadiene. The diene monomers may be used alone or in combination of two or more. The weight ratio of ethylene-propylene rubber to vinyl compounds used for graft polymerization such as aromatic vinyl compounds and vinyl cyanide compounds is suitably in the range of 5:95 to 50:50, and 10:90 to 40:60. A range of is preferred. AB
S resin can be used in bulk polymerization, emulsion polymerization, solution polymerization, and bulk polymerization.
It is produced by a suspension polymerization method, a suspension polymerization method, an emulsion-suspension polymerization method, etc.

Examples of the dried thermoplastic graft polymer include a copolymer obtained by adding both acrylonitrile and styrene graft monomers to a butadiene-based polymer latex and emulsion polymerizing the mixture, and an acrylonitrile-butadiene copolymer and a styrene-acrylonitrile copolymer. Friend polymer etc. obtained by blending (hereinafter referred to as ABS)
(generally referred to as resin). As the butadiene polymer latex, for example, polybutadiene latex, acrylonitrile-butadiene copolymer latex, styrene-butadiene copolymer latex, etc. are used. The ratio 17 of each of the above components is as follows: butane is at most 50 times the weight, steref is at most 85 times the most, and acrylonitrile is at most 5 to 40 times the most.

The thermoplastic polyurethane composition of the present invention can be produced by mixing the above-mentioned thermoplastic polyurethane and a thermoplastic resin containing an aromatic vinyl compound and a vinyl cyanide compound as essential constituents, for example, by mixing the thermoplastic polyurethane described above and a thermoplastic resin containing an aromatic vinyl compound and a vinyl cyanide compound as essential components. After premixing in a predetermined ratio using a type or horizontal mixer, it is mixed using a screw or twin screw extruder, mixing roll,
It is produced by heating and kneading in a batch or continuous manner using a Banbury mixer or the like. Lightfastness when mixed,
Additives such as stabilizers, plasticizers, montan acid wax, lubricants such as aliphatic amide, fillers, antistatic agents, and pigments to improve heat resistance are added in amounts that do not impair the effects of the present invention. It is possible to do so.

The thermoplastic polyurethane composition of the present invention has particularly excellent moldability including injection moldability, and can be easily molded using commonly used injection molding machines, extrusion molding machines, roller molding machines, calendars, etc. be done.

The thermoplastic polyurethane composition of the present invention has high molding dimensional accuracy and excellent heat resistance, cold resistance, oil resistance, abrasion resistance, toughness, and mechanical performance, so it can be used in sheets, films, rolls, etc. Materials for gears, solid tires, snow tires, snow chains, bell l-, watch bands, hoses, tubes, banking materials, anti-vibration materials, shoe soles, sports shoes, and other various laminate products, mechanical parts, automobile parts, and sporting goods. , elastic fibers, etc. In addition, the thermoplastic polyurecne composition of the present invention can be dissolved in a solvent to produce artificial leather, coating agents, fiber treatment agents, adhesives, etc.
Binder Also used in paints, etc.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, in the reference examples, the number average molecular weight was determined according to the following method. The test examples, water resistance, and cold resistance were evaluated according to the following methods. Hard segment content of a thermoplastic polyurethane means the weight proportion in the thermoplastic polyurethane of segments based on diincyaner I- and chain extenders.

(I) Number average molecular weight: Determined from the hydroxyl value and acid value of polyester diol.

(2) Injection moldability: molding cycle time (injection time +
The injection molding was carried out by changing the cooling time (cooling time), and the molding cycle time at which no sink marks or deformation occurred was measured, and the injection bottom shape was evaluated from 1 to 1.

(3) Mechanical performance: A film with a thickness of lOOμ obtained by compression molding a pellet of a polyurethane composition was punched out using a No. 3 dumbbell, and the tensile speed was 30 cm /
The breaking strength and breaking elongation were measured using rnin, and the mechanical performance was evaluated17 accordingly.

(4) Water resistance: A 100μ thick film obtained by compression molding the polyurethane composition Beren 1-
A hydrolysis acceleration test 1- was performed by placing the film in hot water at a temperature of 0.degree. C. for two weeks, and the water resistance was evaluated by the tensile strength retention of the film before and after the test.

(5) Cold resistance: A test piece prepared from a polyurethane composition film with a thickness of 100 μm was measured by temperature dispersion using a dynamic viscoelasticity measuring device [DVE Rheospectra manufactured by Rheology Co., Ltd.]. 9Tα (peak temperature of E!, 1lH
z) was measured, and cold resistance was evaluated based on this.

Reference Example 1 Production of polyester diol 1. Mixture of 9-nonanediol and 2-methyl-1,8-octanediol (molar ratio = 95:5) 2, osof
, and a mixture of adipic acid and inphthalic acid (molar ratio =
so:5o)1. s6og (molar ratio of diol and adipic acid = 1.3:1.0) was charged into a reactor, and while nitrogen gas was passed through the system under normal pressure, the reaction temperature was increased from 160°C to 22°C.
While gradually raising the temperature to 0°C, the condensed water was distilled out of the system, and an esterification reaction was carried out. When the acid value of the polyester became 0.5 or less, the degree of vacuum was gradually increased using a vacuum pump to complete the reaction. The polyester diol thus obtained had a hydroxyl value of 55.8. Acid value 03, number average molecular weight approximately 2,000
It had

Reference Example 2 ~] 1 Manufacture of polyester diol The esterification reaction was carried out in the same manner as in Reference Example 1 except that the dicarboxylic acid giving the dicarboxylic acid component and the diol giving the diol component shown in Table 1 were used, respectively.
Polyester diols shown in Table 1 were obtained.

Regarding the polyester diols obtained in Reference Examples 1 to 11, the diol component and its proportion, the dicarboxylic acid component,
The number average molecular weights are shown in Table IK. In Table 1, diol components and dicarboxylic acid components are represented by diols and dicarboxylic acids represented by the following abbreviations, respectively.

MOD: 2-methyl-1,8-octanediol ND:
1,9-nonanediol 2 HD: 16-hexanediol AD: adivic acid AZA: azelaic acid SA: sebacic acid IPA: inphthalic acid TA: terephthalic acid Below margin Example 1 Production and performance evaluation of polyurethane composition Polyester diol (4 ) and 1,4-butanediol (hereinafter referred to as
This is abbreviated as BD) at a molar ratio of 1 to 2.
4,4-') heated to 50°C and melted to 50°C.
Phenylmethane diisocyanate (hereinafter referred to as MDI)
(abbreviated as ) to polyester diol (4 pairs MDI to B
D was continuously charged into a twin-screw extruder rotating in the same direction using a metering pump in an amount such that the molar ratio of D was 1:3:2, and a continuous melt polymerization reaction was carried out. When the interior of this twin-screw extruder was divided into three zones: a front section, a middle section, and a rear section, the temperature (polymerization temperature) of the middle section, which was the highest temperature, was set at 220°C. The polyurethane produced was continuously extruded into water in the form of a strand, and then formed into pellets using a pelletizer.

3 parts of the obtained polyurethane pellet The mixture was mixed and added at a temperature of 180° C.) to form pellets. Then, obtain 'i'1. The pellets of the polyurethane composition were molded using an injection molding machine (manufactured by Nissei Jushi Kogyo ■, FS80S12ASE, cylinder temperature 175-20
The molded product ( I50mm x 25mm x 6 ribs) was created.

The molding cycle time at which sink marks and deformation stopped occurring was measured for the obtained molded product. Pellets of the above polyurethane composition were then molded according to the method described above, and mechanical performance, water resistance and cold resistance were evaluated. The evaluation results are shown in Table 2.

The above polyurethane composition has injection moldability, mechanical performance,
Both water resistance and cold resistance were good.

Comparative Example 1 Manufacture and Performance Evaluation of Polyurethane Composition 6 A pellet of a polyurethane composition was obtained by the same operation as in Example 1 except that the AS resin was not added, and this pellet was injection molded in the same manner to obtain a molded product. Created. The same evaluation as in Example 1 was performed, and the evaluation results are shown in Table 2. Injection moldability was extremely poor.

Examples 2 to 7 and Comparative Examples 2 to 13 Production and performance evaluation of polyurethane composites In Example 1, polyester diol (polyester diol shown in Table 2 was used instead of the ladle, and polyester diol was added at the molar ratio shown in Table 2). Polyurethane pellets were obtained by carrying out the reaction and operation in the same manner except for charging MDI and BD.These pellets were treated with AS resin (as described above) and ABS in the same manner as in Example 1. A pellet of a polyurethane composition is obtained by adding or not adding a resin (manufactured by Japan Synthetic Rubber, AESllo) or ABS resin (manufactured by Nippon Synthetic Rubber, ABSIO) at a predetermined ratio. The pellets were injection molded in the same manner to produce a molded product.

In Example 1 Perform the same evaluation as that Table 2 shows the evaluation results of Shown below.

Margin below 6r 000) Ll'') 1.1') 0 ++
0 Co DJC'J's
N 廿 -〇 N+ -G) C', I CN G'+ (no's IN OC
Jch CQ Q'l Cn LI') Co (0(
')■Cl'l C1'1 [Effects of the Invention] As is clear from Table 2 above, the thermoplastic polyurethane composition provided by the present invention has excellent injection moldability, mechanical performance, water resistance and Excellent in all aspects of cold resistance. Additionally, the composition has excellent heat resistance, oil resistance, abrasion resistance, and toughness.

Claims (1)

[Scope of Claims] (A) 92 to 99% by weight of thermoplastic polyurethane and (B)
(a) a polyester diol having a number average molecular weight of 1,500 to 3,500; and(
b) diisocyanate and (c) a chain extender, and the sum of the weights of components (b) and (c) is
), (b) and (c) 13-40 for the sum of the weights
%, and the polyester diol has the following structural units (I) and/or (II) as essential structural units derived from diol, and the following structural units (III) as essential structural units derived from dicarboxylic acid. ) and (IV), and the ratio of the mole fraction of the structural unit (I) to the mole fraction of the structural unit (II) is in the range of 100:0 to 50:50, and the structural unit (III ) and the structural unit (IV)
A thermoplastic polyurethane composition characterized in that the molar fraction ratio of is in the range of 80:20 to 35:65. (I): ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II): ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III): ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV): ▲ Mathematical formulas, chemical formulas , tables, etc. ▼ (In the formula, n represents an integer from 4 to 12, and Ar represents a carbon number from 6 to
Represents 12 divalent aromatic hydrocarbon groups. )