JP5982733B2 - Thermoplastic polyurethane resin composition - Google Patents

Description

  The present invention relates to a thermoplastic polyurethane resin composition, and particularly to a thermoplastic polyurethane resin composition excellent in strength, transparency and the like.

  Thermoplastic polyurethane resin has excellent mechanical properties such as tensile strength and compression set, and wear resistance, and exhibits rubber elasticity in a wide temperature range. Therefore, it is widely used as industrial parts, daily necessities, vehicle interior materials, sports equipment, etc. ing. Generally, thermoplastic polyurethane resins are obtained by reacting chain extenders such as polyols, diisocyanates and low molecular weight diols, and consist of hard segments composed of diisocyanates and chain extenders, and soft segments based on polyols. Is done.

  In order to improve the mechanical properties, heat resistance, gas barrier properties, and the like of the thermoplastic polyurethane resin, attempts have been made to disperse the layered clay mineral in the thermoplastic polyurethane resin. However, the layered clay mineral has high hydrophilicity, and the method of simply mixing with the thermoplastic polyurethane resin causes the layered clay mineral to aggregate in the polyurethane resin, and the effect of adding the layered clay mineral cannot be sufficiently obtained. was there.

  Therefore, various methods have been proposed as a method for uniformly dispersing a layered clay mineral in a thermoplastic polyurethane resin. For example, a layered silicate having a cation exchange capacity of 30 meq / 100 g or more is used as an ash content. A thermoplastic polyurethane composition characterized by containing 0.01 to 10% by weight (see, for example, Patent Document 1), an organically modified layered clay mineral was separated into layers and finely dispersed in a thermoplastic urethane elastomer. Thermoplastic urethane elastomer composite materials (see, for example, Patent Document 2) have been proposed.

Japanese Patent Laid-Open No. 08-041315 (refer to the claims) JP 2004-059660 A (refer to the claims)

  However, the uniform dispersibility of the layered silicate in Patent Document 1 refers to a state in which the average particle diameter of the dispersed particles is 5000 angstroms or less, and the average particle diameter is obtained from an image obtained by observation with a transmission electron microscope, for example. The amount is described. In Patent Document 2, the fine dispersion of the layered clay mineral is a state in which when the organically modified layered clay mineral is dispersed in the thermoplastic urethane elastomer, the interlayer distance of the organically modified layered clay mineral is spread by 1.3 nanometers or more. These dispersibility still have problems in fully exhibiting the blending effect of the layered clay mineral, and further improvement in dispersibility has been desired.

  Furthermore, the thermoplastic polyurethane composition of Patent Document 1 is obtained by melting and mixing 0.01 to 40 parts by weight of an intercalation compound and 100 parts by weight of thermoplastic polyurethane under mechanical shearing. The thermoplastic urethane elastomer is obtained by melt-kneading a lamellar clay mineral having an organic substance inserted between layers and a thermoplastic urethane elastomer having a number average molecular weight of 5,000 to 40,000. These thermoplastic elastomers produced by melt-kneading have problems such as fear of thermal deterioration and yellowing, and costs associated with melt-kneading.

  Then, this invention aims at providing the thermoplastic polyurethane resin composition which improves the dispersibility of a layered clay mineral and is excellent in intensity | strength, transparency, etc.

  As a result of intensive studies on the above problems, the present inventors have found that a thermoplastic polyurethane resin composition comprising a combination with a layered clay mineral treated with a specific organic agent and manufactured by a specific method is excellent. The inventors have found that strength, transparency, and the like are expressed, and have completed the present invention.

That is, in the present invention, the HLB value according to the Davis method is within the range of -5 to 1 with respect to 100 parts by weight of the total amount of the urethane prepolymer having a isocyanate group as a terminal group and a diol by reacting polyol and diisocyanate . It is obtained by mixing 0.1 to 10 parts by weight of a layered clay mineral treated with a quaternary ammonium ion and chain-extending the urethane prepolymer, and the blending ratio of the urethane prepolymer and the diol is as follows: The present invention relates to a thermoplastic polyurethane resin composition characterized by satisfying (a) .
(A) When the hydroxyl group mole number of the polyol constituting the urethane prepolymer is (M _OH1 ), the isocyanate group mole number of the diisocyanate is (M _NCO ), and the hydroxyl group mole number of the diol is (M _OH2 ) (M _{NCO -M OH1) / (M OH2} ) a = 0.9 to 1.2.

  The thermoplastic polyurethane resin composition of the present invention is a diol which is a urethane prepolymer as a chain extender in the presence of a layered clay mineral treated with a quaternary ammonium ion having an HLB value in the range of -5 to 1. It is a resin composition prepared by extending the chain by a thermoplastic polyurethane.

  The urethane prepolymer is obtained by reacting a polyol with an excessive amount of diisocyanate with respect to the polyol, and has an isocyanate group as a terminal group.

  Examples of the diisocyanate include 4,4′- or 2,4′-diphenylmethane diisocyanate (also referred to as MDI), toluene diisocyanate, 1,5-phthalene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, and the like. Aromatic diisocyanates; aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, norbornene diisocyanate, isophorone diisocyanate, hydrogenated MDI, etc., among others, a thermoplastic polyurethane resin composition having particularly excellent strength Therefore, 4,4′-diphenylmethane diisocyanate is preferable.

  Examples of the polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol; adipic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic anhydride, maleic acid, fumaric acid Dibasic acids such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 2-methylpropanediol, 3-methyl-1,5-pentanediol Polyester polyols obtained by polycondensation with low molecular weight diol components such as lactones; lactone-based polyester polyols obtained by ring-opening polymerization of cyclic esters such as ε-caprolactone and methylvalerolactone; -Diphenyl carbonate or phosgene is allowed to act on low molecular weight diol components such as butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and 1,8-octanediol. Condensed polycarbonate diols; Polyolefin polyols such as polybutadiene polyols, polyisoprene polyols, and hydrogenated products thereof; and vegetable oil-based polyols such as castor oil-modified polyol, dimer acid-modified polyol, soybean oil-modified polyol, etc., among others Since it becomes a thermoplastic polyurethane resin composition having particularly excellent strength, a polyester polyol is preferable.

  The molecular weight of the polyol may be selected according to the intended thermoplastic polyurethane resin composition, and is particularly preferably 500 to 3,000 because a thermoplastic polyurethane resin composition excellent in strength is obtained. The polyol may be one kind or a combination of two or more kinds, and the ratio is not particularly limited and can be arbitrarily set according to the use.

  And this urethane prepolymer can mix this diisocyanate and this polyol, and can add catalysts, such as an amine compound and an organometallic compound, as needed in the case of a urethanation reaction. Examples of the amine catalyst include triethylenediamine, tetramethylethylenediamine, tetramethylhexylenediamine, dimethylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminoethylamine, dimethylaminooctylamine, dipropylaminopropylamine, triethylamine, Examples include diethylethanolamine and dimethylethanolamine. Examples of the organometallic compound include tin catalysts such as tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dichloride. Etc. The catalysts can be used alone or in combination of two or more.

The ratio of the diisocyanate and the polyol in the urethane prepolymer is arbitrary as long as the urethane prepolymer is obtained, and among them, the thermoplastic polyurethane resin composition having an excellent balance between flexibility and strength, Therefore, the value of (M _NCO ) / (M _OH1 ) when the number of moles of hydroxyl group of the polyol is (M _OH1 ) and the number of moles of isocyanate group of the diisocyanate is (M _NCO ) is in the range of 1.5 to 8. It is preferable that it is a urethane prepolymer.

  The thermoplastic polyurethane resin constituting the thermoplastic polyurethane resin composition of the present invention is obtained by chain-extending the prepolymer with a diol which is a chain extender. Examples of the diol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, 2-methyl-1,3-propanediol. , 3-methyl-1,5-pentanediol, cyclohexanediol, cyclohexanedimethanol and the like, and among them, a thermoplastic polyurethane resin composition having particularly excellent strength can be obtained. It is preferable that

As the layered clay mineral constituting the thermoplastic polyurethane resin composition of the present invention, any layered clay mineral treated with a quaternary ammonium ion having an HLB value in the range of -5 to 1 should be used. The layered clay mineral is obtained by treating the layered clay mineral with a quaternary ammonium ion having an HLB value in the range of -5 to 1, and exchanging exchangeable cations such as sodium and calcium existing between the layers with ammonium. It can be obtained by methods such as a method of ion exchange with ions, a method of modifying by chemical bonds or hydrogen bonds using hydroxyl groups present on the surface of the layered clay mineral. Here, in the case of an untreated layered clay mineral or a layered clay mineral treated with a quaternary ammonium ion whose HLB value is outside the range of -5 to 1, the dispersibility in the thermoplastic polyurethane resin becomes poor, and A thermoplastic polyurethane resin composition cannot be obtained. Here, the HLB value is a value representing the degree of hydrophilicity and hydrophobicity, and the higher the HLB value, the higher the hydrophilicity. In addition, the HLB value in the present invention can be determined by, for example, the Davis method. According to the Davis method, a unique number of functional groups is determined, and “HLB value = 7 + total number of hydrophilic group number + lipophilic oil”. It is defined as the “total number of bases”.

  Examples of layered clay minerals include smectite clay minerals such as montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite; vermiculite, halloysite, swellable mica, etc., and these layered clay minerals are natural products. Or may be a composite, and may be one or a combination of two or more, and the ratio is not particularly limited.

  The quaternary ammonium ion having an HLB value in the range of -5 to 1 is not particularly limited as long as it is within the range of the HLB value. For example, the alkyl group having 1 to 20 carbon atoms, the alkyl group And quaternary ammonium ions having beef tallow, which is a mixture of Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, an octadecyl group, a tetradecyl group, a hexadecyl group, and an octadecyl group. Specific examples of the quaternary ammonium ion include dimethyldioctadecyl quaternary ammonium ion (HLB value: -1.7), dimethyldi-tallow quaternary ammonium ion (HLB value; -0.9), dimethyldihydrogenated Beef tallow quaternary ammonium ion (HLB value: -0.9), and the like.

  The layered clay mineral treated with a quaternary ammonium ion having an HLB value in the range of -5 to 1 may be a commercial product, for example, an organic treatment with dimethyldihydrogenated tallow quaternary ammonium ions. Montmorillonite (manufactured by Southern Clay Products, (trade name) Cloisite 20A), montmorillonite organically treated with dimethyldioctadecyl quaternary ammonium ion (manufactured by Hojun Co., Ltd., (trade name) Sven NX), dimethyldi tallow quaternary ammonium Swellable mica that has been organically treated with ions (manufactured by Coop Chemical Co., Ltd., (trade name) Somasif MAE) and the like are available as commercial products.

  The amount of quaternary ammonium ions contained in the layered clay mineral treated with the quaternary ammonium ions is not particularly limited, and among them, a thermoplastic polyurethane resin composition having particularly excellent transparency and strength is obtained. % Is preferred.

  In addition, the layered clay mineral treated with the quaternary ammonium ion is a thermoplastic polyurethane resin composition that is particularly excellent in transparency, and therefore has an average primary particle size of 0.5 μm to 10 μm. preferable.

  The thermoplastic polyurethane resin composition of the present invention is a layered material treated with quaternary ammonium ions having an HLB value in the range of -5 to 1 with respect to 100 parts by weight of the total amount of the urethane prepolymer and the diol. 0.1 to 10 parts by weight of a clay mineral is mixed and the urethane prepolymer is subjected to a chain extension reaction. Especially, the thermoplastic polyurethane resin composition having excellent strength and transparency is 1 to 10 weights. It is preferable that the part is blended. Here, when the amount of the layered clay mineral is less than 0.1 parts by weight, the obtained polyurethane resin composition has poor mechanical strength. On the other hand, when the layered clay mineral exceeds 10 parts by weight, the layered clay mineral aggregates in the thermoplastic polyurethane resin composition, resulting in poor dispersibility, resulting in a thermoplastic polyurethane resin composition having poor strength and transparency. .

  The thermoplastic polyurethane resin composition of the present invention comprises a mixture of a urethane prepolymer and a diol mixed with a layered clay mineral treated with a quaternary ammonium ion having an HLB value in the range of -5 to 1, and then the urethane. The prepolymer is made to have a high molecular weight by a chain extension reaction to form a thermoplastic polyurethane resin. This makes it possible to disperse the layered clay mineral well in the thermoplastic polyurethane resin, and as a result, heat having excellent strength and transparency. It becomes a plastic polyurethane resin composition. Here, in the case of a thermoplastic polyurethane resin obtained by directly mixing and dispersing a layered clay mineral in a thermoplastic polyurethane resin, the dispersibility of the layered clay mineral is inferior, and the strength and transparency are inferior. For this reason, a low molecular weight polymer has a property of dispersing fine particles in a polymer better than a high molecular weight polymer. Therefore, a layered clay mineral is previously dispersed in a urethane prepolymer. Then, it is considered that good dispersibility is maintained even in the thermoplastic polyurethane resin by performing a chain extension reaction. Further, the quaternary ammonium ion having an HLB value in the range of -5 to 1 on the surface of the layered clay mineral has a high affinity with the urethane prepolymer, and as a result, the interface between the surface of the layered clay mineral and the thermoplastic polyurethane resin. Therefore, the strength of the thermoplastic polyurethane resin composition is particularly excellent.

  The thermoplastic polyurethane resin composition of the present invention is a thermoplastic polyurethane resin composition that is excellent in dispersibility of the layered clay mineral and is excellent in transparency and strength. Therefore, in accordance with JIS K 7136 (2000 version), The value obtained by subtracting the haze value of the thermoplastic polyurethane resin measured in the same manner from the haze value of the thermoplastic polyurethane resin composition measured under the condition that the thickness of the test piece is 0.5 mm, that is, the delta haze is within the range of 0 to 10%. It is preferable to have it.

  Conventionally, as a method for evaluating the dispersibility of the layered clay mineral, direct observation of the dispersion state using a transmission electron microscope (sometimes referred to as TEM) and measurement of the interlayer distance of the layered clay mineral by the X-ray diffraction method are used. It's being used. However, direct observation by TEM is an evaluation method suitable for observing the dispersion state of a very limited portion of the sample, and it cannot be said that the result of TEM observation necessarily shows the average dispersibility of the entire sample. . Moreover, about the interlayer distance of a layered clay mineral, the presence or absence of aggregation of a layered clay mineral cannot necessarily be judged by this evaluation method. On the other hand, the increase in delta haze is that the transparency of thermoplastic polyurethane resin with haze as an indicator deteriorates when blended with lamellar clay minerals. This is because aggregates of lamellar clay minerals are generated in the polyurethane resin. And show that it is distributed. The formation of such agglomerates not only reduces the blending effect of the layered clay mineral, but also significantly decreases the transparency and strength of the thermoplastic polyurethane resin composition. Therefore, the evaluation based on the delta haze is suitable for evaluating the dispersibility of the layered clay mineral in the thermoplastic polyurethane resin composition of the present invention, and serves as an index of transparency, strength, and the like.

  Strength when layered clay mineral treated with quaternary ammonium ions having an HLB value in the range of -5 to 1 constituting the thermoplastic polyurethane resin composition of the present invention is uniformly dispersed in the thermoplastic polyurethane resin. Examples of the effect on the surface include improvement in tensile strength.

  Examples of the method for producing the thermoplastic polyurethane resin composition of the present invention include a layered clay mineral treated with a mixture of the urethane prepolymer and diol and a quaternary ammonium ion having an HLB value in the range of -5 to 1. Are mixed by a general method, and then the urethane prepolymer mixture is supplied to a melt kneader and the urethane prepolymer is subjected to chain extension reaction with a diol, or the urethane prepolymer mixture is filled in a mold, It can be produced by a method of chain extension reaction in the mold. The chain extension reaction can also be carried out by dissolving or dispersing the urethane prepolymer mixture in a solvent. As described above, the thermoplastic polyurethane resin composition of the present invention is obtained by mixing and dispersing the layered clay mineral in the process of producing the thermoplastic polyurethane resin, so that the thermoplastic polyurethane resin and the layered clay mineral are obtained. Compared with a thermoplastic polyurethane resin composition obtained by, for example, melt kneading, the production cost is kept low.

  In the reaction for extending the urethane prepolymer, a catalyst such as an amine compound or an organometallic compound can be added as necessary. Examples of the amine catalyst include triethylenediamine, tetramethylethylenediamine, tetramethylhexylenediamine, dimethylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminoethylamine, dimethylaminooctylamine, dipropylaminopropylamine, triethylamine, Examples include diethylethanolamine and dimethylethanolamine. Examples of the organometallic compound include tin catalysts such as tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dichloride. Etc. The catalysts can be used alone or in combination of two or more.

The ratio of the urethane prepolymer and the diol in the thermoplastic polyurethane resin composition is arbitrary as long as the thermoplastic polyurethane resin composition can be obtained, and among them, the heat having particularly excellent strength and moldability. since the thermoplastic polyurethane resin, a hydroxyl number of moles _{(M OH1)} polyols, hydroxyl number of moles _{(M OH2)} of the diol, in the case of an isocyanate group number of moles of diisocyanate _{(M NCO) (M NCO} - The value of M _OH1 ) / (M _OH2 ) is preferably in the range of 0.9 to 1.2.

  The weight average molecular weight of the thermoplastic polyurethane resin thus obtained is preferably in the range of 50,000 to 1,000,000 because it becomes a thermoplastic polyurethane resin composition having an excellent balance between strength and moldability.

  The thermoplastic polyurethane resin composition of the present invention can be formed into a molded body by a conventionally known molding method. For example, injection molding, injection compression molding, gas assist method injection molding, melt extrusion molding, multilayer extrusion molding, solution casting ( Solution casting), calender molding, rotational molding, hot press molding, blow molding, inflation molding, foam molding, and the like can be molded into injection molded articles, films, tubes, sheets, pipes, bottles and the like.

  Moreover, since the thermoplastic polyurethane resin composition of this invention has the outstanding intensity | strength, transparency, etc., it can be used for the following uses, for example.

  Automotive parts: inner liners for tires, ball joints, dust covers, pedal stoppers, door lock strikers, bushes, spring covers, bearings, anti-vibration parts, interior and exterior parts, tire chains, side molds, timing belts, headrests, seats.

  Machinery, industrial parts; various gears, sealing materials, rollers, packing, vibration-proof parts, pickers, bushes, bearings, caps, connectors, rubber screens, printing drums, O-rings, casters.

  Shoes: Bases, golf, soles and points of soccer shoes, air cushions, women's shoes top lifts, ski shoes, safety shoes.

  Hose, tube; high pressure hose, medical tube, oil / pneumatic tube, air tube, fuel tube, painting hose, fire hose.

Electric wire, cable; power / communication cable, computer / car wiring, various curl cords, etc .; conveyor belt, air mat, diaphragm, keyboard sheet, waterproof sheet, synthetic leather, life jacket, wet suit, roller, grip, watch band, golf Balls, ear tags, various ropes, round belts, V belts, anti-slip, line-of-sight markers, flexible containers, binders, hot melts, adhesives, synthetic leather, ropes, wires, gloves, coatings, food and medical packaging materials , Artificial organs, artificial skin, paper diapers, wound bands, wallpaper.

  The thermoplastic polyurethane resin composition of the present invention can be used in various applications because the layered clay mineral is uniformly dispersed and has excellent strength and transparency.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  Below, the measuring method of each physical-property value is shown.

~ Tensile strength, elongation ~
Based on JIS K 7311 (1995), the tensile speed was measured under the condition of 300 mm / min. The thickness of the test piece was 0.5 mm.

~ Measurement of delta haze ~
A value obtained by subtracting the haze value of the thermoplastic polyurethane resin from the haze value of the thermoplastic polyurethane resin composition measured according to JIS K 7136 (2000) was determined as delta haze. The thickness of the test piece was 0.5 mm.

~ Measurement of YI ~
Measured according to JIS K 7373 (2006). The thickness of the test piece was 0.5 mm.

~ Polyol ~
Polyol A: Polyester polyol manufactured by Nippon Polyurethane Industry Co., Ltd. (trade name) Nipponporan 152, molecular weight: 2000, hydroxyl value: 56 mgKOH / g.

  Polyol B: Polyester polyol manufactured by Nippon Polyurethane Industry Co., Ltd. (trade name) NIPPOLAN 141, molecular weight: 1000, hydroxyl value: 105 mgKOH / g.

~ Diisocyanate ~
4,4'-diphenylmethane diisocyanate (hereinafter referred to as MDI); Nippon Polyurethane Industry Co., Ltd. (trade name) Millionate MT.

~ Layered clay mineral ~
Layered clay mineral A; manufactured by Hojun Co., Ltd., (trade name) S-ben NX (dimethyldioctadecyl quaternary ammonium ion (HLB value; -1.7), montmorillonite, average primary particle size = 1.6 μm, Organic matter amount = 42 wt%).

  Layered clay mineral B; manufactured by Hojun Co., Ltd. (trade name) S-ben NX80 (montmorillonite treated with dimethyldioctadecyl quaternary ammonium ion (HLB value: -1.7), average primary particle size = 1.6 μm, Organic matter amount = 50 wt%).

  Layered clay mineral C; manufactured by Southern Clay Products, (trade name) Cloisite 20A (montmorillonite treated with dimethyldihydrogenated tallow quaternary ammonium ion (HLB value: -0.9), average primary particle size = 1.7 μm , Organic matter amount = 38 wt%).

  Layered clay mineral D: manufactured by Co-op Chemical Co., Ltd. (trade name) Somasifu MAE (swelling mica treated with dimethyl ditallow quaternary ammonium ions (HLB value: −0.9), average primary particle size = 7 μm, Organic content = 39% by weight).

  Layered clay mineral E; manufactured by Hojun Co., Ltd., (trade name) Esbene Nz (montmorillonite treated with dimethyloctadecylbenzyl quaternary ammonium ion (HLB value: 3.6), average primary particle size = 1.6 μm, organic matter Amount = 38% by weight).

  Layered clay mineral F; manufactured by Hojun Co., Ltd., (trade name) Esbene Nz70 (dimethyloctadecylbenzyl quaternary ammonium ion (HLB value: 3.6), montmorillonite, average primary particle size = 1.6 μm, organic matter Amount = 51% by weight).

  Layered clay mineral G: manufactured by Hojun Co., Ltd., (trade name) Esben E (montmorillonite treated with trimethyloctadecyl quaternary ammonium ion (HLB value: 6.4), average primary particle size = 1.6 μm, amount of organic matter = 26% by weight).

Imaginary clay mineral H; manufactured by Southern Clay Products, (trade name) CloisiteNa ⁺ (unmodified organic montmorillonite, average primary particle size = 1.7 μm)
Synthesis example 1
_MDI142g nitrogen purged 1 liter separable flask (M NCO: 1.13mol), polyol _A420g (M OH1: _0.42mol) were charged, for 1 hour 20 minutes of reaction at 80 ° C., to obtain a urethane prepolymer A .

Synthesis example 2
A 1-liter separable flask purged with nitrogen was charged with 165 g of MDI (M _NCO : 1.32 mol) and 330 g of polyol A (M _{OH 1} : 0.33 mol), and reacted at 80 ° C. for 1 hour and 20 minutes to obtain urethane prepolymer B. .

Synthesis example 3
_MDI215g nitrogen purged 1 liter separable flask (M NCO: 1.72mol), polyol _B340g (M OH1: _0.64mol) were charged, for 1 hour 20 minutes of reaction at 80 ° C., to obtain a urethane prepolymer C .

Reference example 1
In a 300 ml polypropylene beaker, 105 g of the urethane prepolymer A obtained in Synthesis Example 1 was provided, and 6.6 g of 1,4-butanediol (M _OH2 : 0.15 mol) was added thereto, and then a disperser (Primix Co., Ltd.) was added. The urethane prepolymer mixture was stirred for 2 minutes under the condition of 1400 revolutions, using (trade name) TK Robotics). Next, the obtained urethane prepolymer mixture was charged into a batch-type melt kneader mixer having an internal volume of 100 ml, and subjected to chain extension reaction by performing melt kneading at 190 ° C. for 11 minutes to obtain a thermoplastic polyurethane resin A. It was.

  Subsequently, using the obtained thermoplastic polyurethane resin, hot press molding was performed at 190 ° C. to obtain a test piece having a thickness of 0.5 mm. The obtained test piece was heat-treated at 105 ° C. for 16 hours and then allowed to stand for 24 hours or more in an atmosphere of 23 ° C. and humidity: 50%, and then the physical properties were measured. The results are shown in Table 3.

Reference Examples 2-3
Thermoplastic polyurethane resins B to C and test pieces were obtained in the same manner as in Reference Example 1 except that the blending ratio of urethane prepolymers B to C and 1,4-butanediol was changed as shown in Table 3. . Table 3 shows the results of measuring physical properties using this test piece.

Example 1
After adding 105 g of urethane prepolymer A obtained in Synthesis Example 1 to a 300 ml polypropylene beaker, 6.6 g of 1,4-butanediol (M _OH2 : 0.15 mol) and 3.0 g of layered clay mineral A were added thereto. The urethane prepolymer mixture was stirred for 2 minutes under the condition of 1400 rotations using a disperser (manufactured by PRIMIX Corporation, (trade name) TK Robotics). Next, the obtained urethane prepolymer mixture was charged into a batch-type melt kneader mixer having an internal volume of 100 ml, and subjected to chain extension reaction by performing melt kneading for 11 minutes at 190 ° C., thereby producing a thermoplastic polyurethane resin composition. Obtained.

  Subsequently, using the obtained thermoplastic polyurethane resin composition, hot press molding was performed at 190 ° C. to obtain a test piece having a thickness of 0.5 mm. The obtained test piece was heat-treated at 105 ° C. for 16 hours and then allowed to stand for 24 hours or more in an atmosphere of 23 ° C. and humidity: 50%, and then the physical properties were measured. The results are shown in Table 2.

Examples 2-7
A thermoplastic polyurethane resin composition was produced in the same manner as in Example 1 except that the blending ratios of urethane prepolymers A to C, 1,4-butanediol, and layered clay minerals A to D were changed as shown in Table 4. And a specimen was obtained. Table 4 shows the results of physical property measurement using this test piece.

Comparative Example 1
By filling the thermoplastic polyurethane resin A111g and the layered clay mineral A3.0g obtained by the method of Reference Example 1 into a batch type melt kneader mixer having an internal volume of 100 ml, and performing melt kneading for 11 minutes at 190 ° C. A thermoplastic polyurethane resin composition was obtained. Next, a test piece was obtained by the same method as in Example 1. Table 5 shows the results of measuring physical properties using this test piece.

Comparative Example 2
Using the thermoplastic polyurethane resin B obtained by the method of Reference Example 2, a thermoplastic polyurethane resin composition and a test piece were obtained by the same method as in Comparative Example 1. Table 5 shows the results of measuring physical properties using this test piece.

Comparative Example 3
Using the thermoplastic polyurethane resin C obtained by the method of Reference Example 3, a thermoplastic polyurethane resin composition and a test piece were obtained by the same method as in Comparative Example 1. Table 5 shows the results of measuring physical properties using this test piece.

Comparative Examples 4-8
Except for changing the blending ratio of urethane prepolymer A, 1,4-butanediol, lamellar clay minerals A, E, F, G, and H as shown in Table 5, thermoplasticity was obtained in the same manner as in Example 1. A polyurethane resin composition and a test piece were obtained. Table 5 shows the results of measuring physical properties using this test piece.

  Since the thermoplastic polyurethane resin composition of the present invention is excellent in strength, transparency, etc., it can be used as a raw material for various industrial applications.

Claims (6)

A quaternary ammonium ion having an HLB value by the Davis method in the range of -5 to 1 with respect to 100 parts by weight of the total amount of urethane prepolymer having an isocyanate group as an end group and a diol, which is a reaction product of a polyol and a diisocyanate. The urethane prepolymer is chain-extended with the diol in the presence of 0.1 to 10 parts by weight of the layered clay mineral treated with the following, and the blending ratio of the urethane prepolymer and the diol is as follows: A thermoplastic polyurethane resin composition characterized by satisfying (a).
(A) When the hydroxyl group mole number of the polyol constituting the urethane prepolymer is (M _OH1 ), the isocyanate group mole number of the diisocyanate is (M _NCO ), and the hydroxyl group mole number of the diol is (M _OH2 ) (M _{NCO -M OH1) / (M OH2} ) a = 0.9 to 1.2. 2. The thermoplastic polyurethane resin composition according to claim 1, wherein the urethane prepolymer is a urethane prepolymer comprising 4,4'-diphenylmethane diisocyanate and a polyester polyol. The thermoplastic polyurethane resin composition according to claim 1 or 2, wherein the diol is 1,4-butanediol. The thermoplastic polyurethane resin composition according to any one of claims 1 to 3, wherein the layered clay mineral has an average primary particle size of 0.5 µm to 10 µm. According to JIS K 7136 (2000 version), the delta haze value calculated by the following formula (1) is within the range of 0 to 10% from the haze value measured under the condition that the thickness of the test piece is 0.5 mm. The thermoplastic polyurethane resin composition according to any one of claims 1 to 4.
Delta haze (%) = (ab) (1)
(Where a is the haze value of the thermoplastic polyurethane resin composition, b is a thermoplastic polyurethane resin comprising a urethane prepolymer and diol corresponding to the thermoplastic polyurethane resin composition from which a is measured, and containing no layered clay mineral. The haze value is shown.) A quaternary ammonium ion having an HLB value in the range of -5 to 1 with respect to a total amount of 100 parts by weight of a mixture of a urethane prepolymer having an isocyanate group as a terminal group by reacting a polyol and a diisocyanate and a diol. 0.1 to 10 parts by weight of the layered clay mineral treated in step 1 is mixed, and the urethane prepolymer is subjected to chain extension reaction, and the blending ratio of the urethane prepolymer and the diol satisfies the following (a): A process for producing a thermoplastic polyurethane resin composition.
(A) When the hydroxyl group mole number of the polyol constituting the urethane prepolymer is (M _OH1 ), the isocyanate group mole number of the diisocyanate is (M _NCO ), and the hydroxyl group mole number of the diol is (M _OH2 ) (M _{NCO -M OH1) / (M OH2} ) a = 0.9 to 1.2.