KR100788793B1 - Thermoplastic polyurethane resin composition having excellent low-temperature toughness and transparency - Google Patents

Abstract

The present invention relates to a thermoplastic polyurethane resin composition having excellent low temperature impact strength and transparency, and more particularly, to a polyurethane resin comprising (A) a thermoplastic polyurethane resin and (B) a MBS-based thermoplastic graft polymer. By making the graft polymer, the rubber latex used for its manufacture, and the refractive index of the said thermoplastic polyurethane resin equal, the thermoplastic polyurethane resin composition excellent in transparency and low temperature impact strength is provided.

The thermoplastic resin composition according to the present invention is very excellent in low temperature impact strength at -20 ° C or lower without deterioration of transparency.

Low temperature impact strength, transparency, thermoplastic, polyurethane, rubber latex, styrene-butadiene rubber, refractive index

Description

Thermoplastic polyurethane resin composition having excellent low-temperature toughness and transparency

The present invention relates to a thermoplastic polyurethane (hereinafter referred to as "TPU") resin composition, and more particularly to an alkyl (meth) acrylate-conjugated diene monomer-ethylenically unsaturated aromatic compound (hereinafter referred to as "MBS") Thermoplastic) comprising a graft copolymer and a thermoplastic polyurethane resin, wherein the refractive index of the rubber latex, which is a substrate of the graft polymer, and the refractive index of the graft polymer are the same as those of the thermoplastic polyurethane resin, thereby providing excellent low temperature impact strength and transparency. It relates to a polyurethane resin composition.

In order to improve the low temperature flexibility of the TPU, a resin composition composed of TPU resin and graft rubber has been studied for a long time.

US Pat. Nos. 3,049,505 and 4,317,890 disclose resin compositions consisting of acrylonitrile-butadiene-styrene (ABS) graft copolymers and polyurethanes. However, the above methods, the resin composition using the TPU resin and ABS graft copolymer is insignificant in the degree of improvement in low-temperature impact strength, and opaque due to the difference in refractive index of the two components.

In order to solve the problems of the prior art, it is an object of the present invention to provide a method for producing a MBS graft copolymer that can improve the low-temperature impact strength while maintaining the transparency of the TPU resin and a resin composition using the same.

In order to achieve the above object, the present invention (A) 50 to 95% by weight thermoplastic polyurethane; And (B) 5 to 50% by weight of the MBS-based thermoplastic graft polymer,

The thermoplastic graft polymer,

a) 50 to 85% by weight of a rubber latex consisting of a conjugated diene monomer-ethylenically unsaturated aromatic compound; And

b) graft polymerization of 15 to 50% by weight of one or more monomers selected from the group consisting of alkyl (meth) acrylates and ethylenically unsaturated aromatic compounds,

The refractive index (Z) of the thermoplastic graft polymer (X), the rubber latex (Y) used to manufacture the graft polymer, and the thermoplastic polyurethane resin is satisfactory transparency and low temperature impact satisfying the relationship represented by the following equations (1) and (2). Provided is a thermoplastic polyurethane resin composition having excellent strength.

(Equation 1)

0 ≤ | X-Y | ≤ 0.005

(Equation 2)

0 ≤ | X-Z | ≤ 0.005

(Wherein X is the refractive index of the thermoplastic graft polymer, Y is the refractive index of the rubber latex used to prepare the graft polymer, and Z is the refractive index of the thermoplastic polyurethane resin.)

In addition, the present invention a) preparing a rubber latex by emulsion polymerization by introducing a conjugated diene monomer, an ethylenically unsaturated aromatic compound and a crosslinking agent into the reactor; And b) 15 to 50% by weight of at least one monomer selected from the group consisting of alkyl (meth) acrylate having 1 to 20 carbon atoms and an ethylenically unsaturated aromatic compound having 50 to 85% by weight of the rubber latex. Preparing a thermoplastic graft polymer by multi-step graft polymerization of at least one step;

The refractive index of the thermoplastic graft polymer and the rubber latex used in the graft polymer production provides a method for producing a MBS graft copolymer for a thermoplastic polyurethane resin composition that satisfies the relationship represented by Equation 1 below.

(Equation 1)

0 ≤ | X-Y | ≤ 0.005

(Wherein, X is the refractive index of the thermoplastic graft polymer, Y is the refractive index of the rubber latex used to prepare the graft polymer.)

Hereinafter, the present invention will be described in detail.

The present inventors equalize the refractive index of the rubber latex and the graft polymer, which are the substrates of the MBS graft polymer, in preparing the thermoplastic resin composition comprising the thermoplastic polyurethane resin (TPU) and the MBS graft polymer. By adjusting the refractive index of the same as the refractive index of the thermoplastic polyurethane, the low temperature impact strength and the transparency of the thermoplastic resin composition were found to change, thereby completing the present invention.

In particular, the refractive index of the grafting polymer in the present invention is proportional to the weight ratio. That is, the refractive index of the graft polymer is determined by the refractive index and content of the rubber latex used in the manufacture of the graft polymer, the components of the grafted monomer, and the respective contents. Further, in manufacturing the thermoplastic resin composition, by adjusting the refractive index of the rubber latex and the refractive index of the graft polymer to be equal to the refractive index of the thermoplastic polyurethane, not only the transparency but also the low temperature impact strength can be improved. For example, according to the present invention, the refractive index of material C consisting of A and B materials satisfies the relationship RI _C = RI _A * Wt _A + RI _B * Wt _B (where RI _C is the refractive index of C, RI _A is the refractive index of A, Wt _A is the weight of A, RI _B is the refractive index of B, Wt _B Is the weight of B.)

Preferably, the refractive index relationship between the thermoplastic graft polymer, the rubber latex used to manufacture the graft polymer, and the thermoplastic polyurethane resin satisfies the formulas represented by Equations 1 and 2 below to improve transparency and low temperature impact strength. Can be.

(Equation 1)

0 ≤ | X-Y | ≤ 0.005

(Equation 2)

0 ≤ | X-Z | ≤ 0.005

Wherein X, Y and Z are as defined above.

More preferably, in the present invention, the difference in refractive index between the graft polymer (X) and the rubber latex (Y) used for the production of the graft polymer is approximately equal to about 0.0000 to 0.0020 (Equation 1a). In addition, the difference between the refractive index (X) of the graft polymer and the refractive index (Z) of the polyurethane resin is also preferably 0.0000 to 0.0020 (Equation 2a).

(Equation 1a)

0.0000 ≤ | X-Y | ≤ 0.0020

(Equation 2a)

0.0000 ≤ | X-Z | ≤ 0.0020

(Wherein X, Y, and Z are as defined above).

The TPU is a rubbery elastomer having a urethane group (-NHCOO-) in its molecular structure, and is processed through injection, extrusion, calendar, tee-die, and the like. Thermoplastic polyurethane resin is excellent in mechanical strength and abrasion resistance, and has excellent properties such as bend resistance, coloring, and feel.It is harmless to human body because there is no danger of environmental hormone, and it does not emit air or soil pollutants when incinerated. Friendly.

Conjugated diene-based monomers and ethylene-saturated aromatic compounds that can be used in the production of the rubber latex are used to control the glass transition temperature and the refractive index of the rubber latex, the content and type of the TPU and the desired physical properties It is possible to change accordingly. Therefore, the content of the conjugated diene monomer, the ethylenically unsaturated aromatic compound and the crosslinking agent used for crosslinking thereof is not specifically limited in the present invention.

In addition, the conjugated diene monomer used in the production of the rubber latex serves to absorb shock from the outside to improve impact resistance, for example, butadiene, isoprene and chloroisoprene selected from the group consisting of at least one. Can be.

The ethylenically unsaturated aromatic compound used in the production of rubber latex serves to maintain the transparency by suppressing the scattering of light caused by the refractive index difference by making the refractive index of the rubber latex equal to the TPU. The ethylenically unsaturated aromatic compound may be selected from the group consisting of styrene, alphamethylstyrene, isopropenyl naphthalene, vinylnaphthalene, alkyl styrene substituted with C ₁ to C ₃ alkyl group, and styrene substituted with halogen. Can be.

In addition, a crosslinking agent may be used when preparing the SB-based rubber latex, and the crosslinking agent used serves to control the degree of crosslinking of the rubber latex. Examples of crosslinking agents include divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, aryl methacrylate and It is preferable that it is 1 or more types of compounds chosen from the group which consists of 1, 3- butylene glycol diacrylate.

In addition, the amount of the crosslinking agent may be used in an amount of 5% by weight or less based on 100% by weight of the total monomer, but in order to improve the low temperature impact strength of the TPU resin, it is preferable to use 2% by weight or less.

The production method of the rubber latex in the present invention is not particularly limited and can be prepared by methods well known to those skilled in the art. The particle size and gel content of the rubber latex of the present invention are also not particularly limited.

In addition, the MBS-based graft copolymer production method of the present invention is a group consisting of 50 to 85% by weight of the rubber latex prepared by the above method, and alkyl (meth) acrylate and ethylenically unsaturated aromatic compound having 1 to 20 carbon atoms Graft emulsion polymerization of 15 to 50% by weight of one or more monomers selected from one step or multiple steps.

Particularly, in the present invention, the graft polymer is prepared through one or more steps of one or more multistage polymerization steps using at least one monomer selected from the group consisting of rubber latex and alkyl (meth) acrylates and ethylenically unsaturated aromatic compounds. In this case, in one or more stages of multistage polymerization, the monomer component grafted to the rubber latex may be different for each stage. However, the content in the first and second stages may vary depending on the type of monomer to be grafted and the refractive index value of interest.

If the amount of rubber latex is less than 50% by weight when the MBS graft copolymer is manufactured, there is a problem that the low-temperature impact strength is reduced. There is a problem of poor physical properties.

The alkyl (meth) acrylate serves to increase the compatibility of the rubber latex and TPU, for example methyl methacrylate, ethyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate and butyl acryl One or more types can be selected and used from the group which consists of a rate etc.

The ethylenically unsaturated aromatic compound serves to maintain the transparency by suppressing the scattering of light generated by the refractive index difference by making the refractive index of the MBS graft copolymer equal to PVC. The ethylenically unsaturated aromatic compound may be the same as that used in the production of the rubber latex.

In the production method of the present invention, the reaction medium, the initiator, the emulsifier, the catalyst, the stabilizer and the like can be used in a conventional content without particular limitation as long as it is known in the art. For example, the emulsifier may be selected from various kinds well known in the emulsion polymerization technique, preferably fatty acid salts such as fatty acid potassium salts, potassium oleate salts and alkali metal salts of weak acids. The polymerization initiator may be a water-soluble polymerization initiator such as sodium persulfate, potassium persulfate or a peroxy compound, or cumene hydroperoxide, diisopropyl benzenehydro peroxide, azobis isobutylnitrile or tertiary butyl hydroperoxide. Fat-soluble polymerization initiators such as, paramethane hydroperoxide, or benzoyl peroxide can be used. In this regard, reference is made to the description of the examples.

Polymerization conditions of the rubber latex and MBS graft polymer in the present invention is also not particularly limited.

On the other hand, it is preferable that the thermoplastic polyurethane resin composition of this invention consists of 5-50 weight% of said MBS graft polymers, and 50-95 weight% of TPU resins.

When the amount of the MBS graft copolymer is less than 5% by weight, the effect of improving low temperature impact strength is small, and when the amount of the MBS graft copolymer is more than 50% by weight, the mechanical strength of the resin composition is lowered.

In addition, the thermoplastic resin composition of the present invention may further include additives such as process oils, lubricants, antioxidants, heat stabilizers, lubricants, and pigments known in the art, if necessary.

The transparency of the thermoplastic resin composition composed of the MBS graft polymer and the TPU resin prepared as described above had a Haze value of 5 or less using a Haze Meter of ASTM D1003 standard, and the low temperature impact strength was 400 at -20 ° C. by the following evaluation method. It is preferable that it is rpm or more.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, an Example is for illustrating this invention and does not limit this invention only to these.

EXAMPLE

Example  One

(Manufacture of rubber latex)

The weight percentages of the following compounds are based on 100% by weight of the total amount of monomers used for the preparation of rubber latex, and parts by weight are based on 100 parts by weight of the total amount of the monomers.

In a 120 liter high pressure polymerization vessel equipped with a stirrer, 150 parts by weight of ion-exchanged water, 0.5 parts by weight of a buffer solution as an additive, 1.0 parts by weight of potassium oleate, 0.0047 parts by weight of ethylenediamine tetrasodium acetate, 0.003 parts by weight of ferrous sulfate, sodium 0.02 parts by weight of formaldehyde sulfoxy acid and 0.1 parts by weight of diisopropylbenzene hydroperoxide were initially charged.

To this, 75% by weight of butadiene, 24% by weight of styrene and 1% by weight of divinylbenzene were polymerized at 50 ° C. for 16 hours to obtain a styrene-butadiene rubber latex having a particle size of 1000 mm 3, and the final polymerization conversion thereof was 98%. It was.

(Production of MBS Graft Polymer)

The weight percentages of the following compounds are based on 100% by weight of the total amount of the styrene-butadiene rubber latex and newly added monomers used for preparing the graft copolymer, and the weight parts are based on the SB-based rubber latex and the newly added monomers. The total amount is based on 100 parts by weight.

The obtained styrene-butadiene rubber latex 70% by weight (solid content) was added to a closed reactor, and charged with nitrogen, and 0.0094 parts by weight of ethylenediamine tetrasodium acetate, 0.006 parts by weight of ferrous sulfate, and sodium formaldehyde sulfide. After adding 0.04 parts by weight of oxycylate, 15% by weight of methyl methacrylate, 0.15 parts by weight of potassium oleate, 15 parts by weight of ion-exchanged water, and 0.05 parts by weight of t-butyl hydroperoxide were added to polymerize at 60 ° C. for 2 hours. Then, 0.0094 parts by weight of ethylenediamine tetrasodium acetate, 0.006 parts by weight of ferrous sulfate, 0.04 parts by weight of sodium formaldehyde sulfoxylate, 15% by weight of styrene, 0.15 parts of potassium oleate, 15 parts by weight of ion-exchanged water, and After adding 0.05 part by weight of t-butyl hydroperoxide, polymerization was performed at 60 ° C. for 2 hours.

(Preparation of MBS Graft Polymer Powder)

0.5 parts by weight of antioxidant (Irganox-245) and 2.0 parts by weight of hydrochloric acid were added to the graft copolymer (MBS graft copolymer) reaction solution of methyl methacrylate-butadiene-styrene prepared in Examples and Comparative Examples. The polymer and water were separated at 70 ° C. and then dehydrated to obtain MBS powder.

Preparation of TPU Resin Composition Specimen

75 wt% of a TPU resin having a refractive index of 1.5360 and 25 wt% of the MBS-based graft polymer prepared by the above method were mixed, and a 0.5 mm thick sheet was prepared for low temperature rotational impact strength measurement using a roll at 160 ° C. .

Example  2

The same procedure as in Example 1 was carried out except that 15 wt% of styrene was added in one step and 15 wt% of methyl methacrylate was added in two steps.

Example  3

In the same manner as in Example 1, except that the polymerization was carried out by adding 20% by weight of methyl methacrylate in one step and 20% by weight of styrene in two steps to 60% by weight of the rubber latex when the MBS graft polymer was polymerized.

Example  4

In the same manner as in Example 1, except that the polymerization was carried out by adding 10% by weight of methyl methacrylate in one step and 10% by weight of styrene in two steps to 80% by weight of the rubber latex when the MBS graft polymer was polymerized.

Comparative example  One

In the same manner as in Example 1 except that the polymerization was carried out by adding 95% by weight of butadiene, 4% by weight of styrene and 1% by weight of divinylbenzene during the polymerization of rubber latex.

Comparative example  2

In the same manner as in Example 1, except that 55 wt% butadiene, 44 wt% of styrene and 1 wt% of divinylbenzene were polymerized by polymerizing rubber latex.

Comparative example  3

In the same manner as in Example 1 except that the polymerization was carried out by adding 30% by weight of methyl methacrylate in one step and 25% by weight of styrene in two steps to 45% by weight of the rubber latex when the MBS graft polymer was polymerized.

Comparative example  4

In the same manner as in Example 1, except that the polymerization was performed by adding 5% by weight of methyl methacrylate in 5 steps and 5% by weight of styrene in 2 steps to 90% by weight of the rubber latex when the MBS graft polymer was polymerized.

Comparative example  5

The same process as in Example 1 except that the TPU resin composition was prepared using 40% TPU resin and 60% by weight of MBS-based graft polymer.

Comparative example  6

The same process as in Example 1 was performed except that 99% of TPU resin and 1% by weight of MBS graft polymer were used to prepare the TPU resin composition specimen.

[Performance test method]

Refractive index evaluation

The refractive index was measured at 25 ° C. using an Abbe Refractometer.

Evaluation of low temperature impact strength

Low-temperature impact strength was obtained by cutting the sheet prepared by the method in Example 1, and fabricating a specimen 0.5 mm thick and 10 cm x 14 cm, aged at -20 ° C. for 2 hours, and then rotating the circular saw blade to the saw blade at a speed of 15 mm / sec. The lowest rpm at which the specimen was broken was measured.

Evaluation of transparency

The sheet prepared by the above method was prepared using a heat press to prepare a specimen of 3mm thickness for the transparency measurement of ASTM D1003 standard and measured the Haze value using a Haze Meter.

The content of graft polymer used in the TPU resin composition, the rubber latex content and the composition of the monomers according to Examples 1 to 4 and Comparative Examples 1 to 6, and thus the refractive index, transparency and low temperature of the rubber latex and the graft polymer, respectively The impact strength was measured and shown in Table 1, respectively.

Graft Polymer Content (wt%) Monomer composition (% by weight) of the polymerization stage of the graft polymer Refractive index Transparency (Haze) Low temperature impact strength (rpm) Rubber latex 1 ^st grafting 2 ^nd grafting Rubber latex Graft polymer Example 1 25 70 MMA 15 SM 15 1.5355 1.5369 2.8 550 Example 2 25 70 SM 15 MMA 15 1.5355 1.5369 2.5 500 Example 3 25 60 MMA 20 SM 20 1.5355 1.5374 2.0 450 Example 4 25 80 MMA 10 SM 10 1.5355 1.5364 4.5 600 Comparative Example 1 25 70 MMA 5 SM 25 1.5207 1.5367 8.2 400 Comparative Example 2 25 70 MMA 25 SM 5 1.5503 1.5371 7.6 300 Comparative Example 3 25 45 MMA 30 SM 25 1.5355 1.5355 1.8 200 Comparative Example 4 25 90 MMA 5 SM 5 1.5355 1.5360 6.6 250 Comparative Example 5 60 70 MMA 15 SM 15 1.5355 1.5369 3.8 380 Comparative Example 6 One 70 MMA 15 SM 15 1.5355 1.5369 1.6 200

In Table 1, MMA represents methyl methacrylate and SM represents styrene, respectively.

As shown in Table 1, it was confirmed that the transparency and low temperature impact strength of the TPU resin composition were changed when the refractive index and content of the rubber latex were changed. That is, when the refractive index of the rubber latex is almost the same as that of the TPU resin as in Examples 1 to 4, the transparency and low temperature impact strength are excellent, but when the difference in the refractive index is large as in Comparative Examples 1 to 2, it is opaque. Done In addition, as in Comparative Examples 3 to 4, even when the refractive index of the rubber latex was the same as that of the TPU resin, when the content of the rubber latex was too low or high, there was no effect of improving the low temperature impact strength. In addition, when too little or too much MBS-based graft polymer is used in the TPU resin composition as in Comparative Examples 5 to 6, there is no effect of improving the low temperature impact strength or the mechanical strength of the resin composition is lowered.

Therefore, it was confirmed that the MBS-based graft polymer using a rubber latex having the same refractive index as the TPU resin according to the present invention as a substrate may have excellent transparency and low temperature impact strength.

As described above, when the MBS graft copolymer prepared by the method of the present invention is used together with the TPU resin, a TPU resin composition having excellent transparency and low temperature impact strength can be produced.

While several embodiments of the invention have been disclosed and described, those skilled in the art will understand that changes can be made to these embodiments without departing from the spirit and spirit of the invention. Therefore, the scope of the present invention is defined by the following claims and their equivalents.

Claims (11)

(A) 50 to 95% by weight thermoplastic polyurethane resin; And (B) A thermoplastic polyurethane resin composition comprising 5 to 50% by weight of an MBS-based thermoplastic graft polymer, The thermoplastic graft polymer, a) 50 to 85% by weight of a rubber latex consisting of a conjugated diene monomer-ethylenically unsaturated aromatic compound; And b) graft polymerization of 15 to 50% by weight of at least one monomer selected from the group consisting of alkyl (meth) acrylates having 1 to 20 carbon atoms and ethylenically unsaturated aromatic compounds, The refractive index (X) of the thermoplastic graft polymer, the refractive index (Y) of the rubber latex used to manufacture the graft polymer, and the refractive index (Z) of the thermoplastic polyurethane resin satisfy the relationship represented by the following equations (1) and (2). Thermoplastic polyurethane resin composition excellent in transparency and low temperature impact strength. (Equation 1) 0 ≤ | X-Y | ≤ 0.005 (Equation 2) 0 ≤ | X-Z | ≤ 0.005 (Wherein, X is the refractive index of the (B) thermoplastic graft polymer, Y is the refractive index of the a) rubber latex used to prepare the graft polymer, Z is the refractive index of the (A) thermoplastic polyurethane resin.) The method according to claim 1, wherein the difference between the refractive index (X) of the thermoplastic graft polymer and the refractive index (Y) of the rubber latex used to prepare the graft polymer, and the refractive index (X) of the thermoplastic graft polymer and the thermoplastic polyurethane The difference in refractive index (Z) of the resin is 0.0000 to 0.0020 thermoplastic polyurethane resin composition, respectively. The thermoplastic polyurethane resin composition of claim 1, wherein the conjugated diene monomer is selected from the group consisting of butadiene, isoprene, and chloroisoprene. According to claim 1, wherein the alkyl (meth) acrylate is selected from the group consisting of methyl methacrylate, ethyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate Phosphorus thermoplastic polyurethane resin composition. The method according to claim 1, wherein the ethylenically unsaturated aromatic compound is selected from the group consisting of styrene, alphamethylstyrene, isopropenyl naphthalene, vinylnaphthalene, alkyl styrene substituted with C ₁ to C ₃ alkyl group, and styrene substituted with halogen. Thermoplastic polyurethane resin composition is selected from at least one species. The thermoplastic polyurethane resin composition of claim 1, wherein the thermoplastic resin composition further comprises at least one additive selected from the group consisting of process oils, lubricants, antioxidants, heat stabilizers, lubricants, and pigments. i) preparing a rubber latex by emulsion polymerization by adding a conjugated diene monomer, an ethylenically unsaturated aromatic compound and a crosslinking agent to the reactor; ii) 50 to 85% by weight of the rubber latex 15 to 50% by weight of one or more monomers selected from the group consisting of alkyl (meth) acrylates and ethylenically unsaturated aromatic compounds having 1 to 20 carbon atoms in one step or one step Preparing a thermoplastic graft polymer by the above multi-stage graft polymerization; And iii) mixing 5 to 50 weight percent of said thermoplastic graft polymer and 50 to 95 weight percent of thermoplastic polyurethane resin, The refractive index (X) of the thermoplastic graft polymer, the refractive index (Y) of the rubber latex used to manufacture the graft polymer, and the refractive index (Z) of the thermoplastic polyurethane resin are represented by the following formulas (1) and (2). A method for producing a thermoplastic polyurethane resin composition according to claim 1. (Equation 1) 0 ≤ | X-Y | ≤ 0.005 (Equation 2) 0 ≤ | X-Z | ≤ 0.005 Wherein X is the refractive index of the thermoplastic graft polymer in step iii), Y is the refractive index of the rubber latex used to prepare the graft polymer in step ii), and Z is the refractive index of the thermoplastic polyurethane resin in step iii). .) The method of claim 7, wherein the conjugated diene monomer is selected from the group consisting of butadiene, isoprene and chloroisoprene. According to claim 7, wherein the alkyl (meth) acrylate is selected from the group consisting of methyl methacrylate, ethyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate The manufacturing method of phosphorus thermoplastic polyurethane resin composition. According to claim 7, wherein the ethylenically unsaturated aromatic compound is a group consisting of styrene, alpha methyl styrene, isopropenyl naphthalene, vinyl naphthalene, alkyl styrene substituted with an alkyl group of C ₁ to C ₃ , and styrene substituted with halogen Method for producing a thermoplastic polyurethane resin composition is selected from one or more. The method of claim 7, wherein the crosslinking agent is divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, aryl A method for producing a thermoplastic polyurethane resin composition which is at least one compound selected from the group consisting of methacrylate and 1,3-butylene glycol diacrylate.