JPH11256028A - Thermoplastic polyurethane composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a molded product such as a film or a sheet having not only a moderate strength but also a small residual strain after elongation, and also excellent adhesion to various base materials with high productivity. To provide a thermoplastic polyurethane composition which can be produced by the above method and a molded article comprising the composition. SOLUTION: The number of hydroxyl groups per molecule is from 2.01 to 2.10, and the number average molecular weight is from 500 to 8000, comprising a polymer polyol unit, an organic diisocyanate unit and a chain extender unit, and having a nitrogen atom content of 2.5% by weight. The following thermoplastic polyurethane (a), a polyester diol unit having a number average molecular weight of 1500 to 5000, comprising an organic diisocyanate unit and a chain extender unit, the nitrogen atom content is 2.6% by weight or more,
Differential scanning calorimetry shows an endothermic peak at 200 to 220 ° C., and the crystallization enthalpy determined from this endothermic peak is 2 to 15 J / g
Consisting of a thermoplastic polyurethane (b) and an ethylene-α-olefin copolymer (c), based on the total weight of components (a) and (b), 40 to 80% by weight of component (a), (b) 60 ~
A thermoplastic polyurethane composition containing 20% by weight and 5 to 250% by weight of the component (c); and a molded article comprising the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyurethane composition comprising two kinds of thermoplastic polyurethanes and an ethylene-.alpha.-olefin copolymer, and a film, a sheet and other molded articles comprising the thermoplastic polyurethane composition. About goods. The thermoplastic polyurethane composition of the present invention is excellent in melt moldability, and particularly has an appropriate strength by melt extrusion molding or inflation molding, and has not only small residual strain after elongation but also adhesion to various substrates. Molded articles such as films and sheets having excellent properties can be manufactured with high productivity.

[0002]

2. Description of the Related Art Thermoplastic polyurethane has mechanical performance,
Because of its excellent properties such as abrasion resistance, elastic recovery, oil resistance, and flexibility, it is attracting attention as a substitute for rubber and plastic. For example, films and sheets formed by extrusion of thermoplastic polyurethane have attracted attention as stretchable materials for disposable diapers. The stretchable film for a disposable diaper is intended to prevent the disposable diaper from coming off the body with an appropriate force when the disposable diaper is mounted, and preventing the disposable diaper from falling off the body.

In recent years, adult nursing care diapers have been marketed in addition to infants. The elastic film used for disposable diapers for adults with a higher momentum than infants has a moderate strength that does not stretch with a small force compared to the elastic film used for disposable diapers for infants,
It is required to have such characteristics that a stress (recovery stress) for returning to an original shape after elongation is high and dimensional stability is excellent (residual strain is small).

Therefore, in order to satisfy such a demand,
Attempts have been made to reduce the hardness of thermoplastic polyurethane. In such a method, when a molded article such as a film or sheet is melt-extruded using a T-die extruder or the like, a T-die is used. A phenomenon in which the width of the extruded molded product becomes significantly narrower than the effective width of the T-die (hereinafter referred to as “neck-in phenomenon”) occurs, and only a molded product having uneven thickness at both ends can be obtained. . Therefore, in order to obtain a uniform molded article without uneven thickness, it is necessary to trim portions having uneven thickness at both ends of the molded article, and the productivity of the molded article is very poor. Furthermore, since the obtained molded article has poor blocking resistance, when producing molded articles such as films and sheets, it is necessary to produce the molded articles using expensive release paper, for example, which is extremely troublesome and costly. There is a problem that it takes.

In recent years, in order to improve the low-temperature impact resistance of a thermoplastic polyurethane while maintaining the characteristics of the thermoplastic polyurethane, a specific ethylene-α-olefin has been added to generally commercially available thermoplastic polyurethanes. It has been proposed to incorporate a copolymer (Japanese Unexamined Patent Publication No. Hei 8-
No. 501343).

[0006]

However, according to the study of the present inventors, it has been found that a T-die type extrusion is not possible simply by blending an ethylene-α-olefin copolymer with a commercially available thermoplastic polyurethane. It has been found that the neck-in phenomenon that occurs when a molded article such as a film or sheet is melt-extruded using a machine or the like is not sufficiently improved. Further, it has been found that when a molded article such as a film or a sheet is melt-molded from this thermoplastic polyurethane composition using an inflation molding machine, unevenness in thickness and cracks are likely to occur.

An object of the present invention is to improve the neck-in phenomenon that occurs when melt-extrusion molding is performed by a T-die type extruder or the like, and the thickness unevenness and cracks that occur when melt-molding is performed by an inflation forming machine. A thermoplastic polyurethane composition that can produce molded products such as films and sheets that have not only low residual strain after elongation but also excellent adhesion to various substrates with high productivity. To provide. It is a further object of the present invention to provide a molded article such as a film or sheet made of the thermoplastic polyurethane composition.

[0008]

As a result of repeated studies by the present inventors to achieve the above object, the number of hydroxyl groups per molecule of thermoplastic polyurethane is from 2.01 to 2.10.
It has been found that it is important to use a thermoplastic polyurethane having specific crystallinity in combination with a low-hardness thermoplastic polyurethane containing a high molecular weight polyol unit. Furthermore, as a result of repeated studies based on these findings, the number of hydroxyl groups per molecule is from 2.01 to 2.10.
5% by weight or less of a thermoplastic polyurethane (a), and a nitrogen atom content of 2.6% by weight or more of a thermoplastic polyurethane (b) having a specific enthalpy of crystallization,
By blending the ethylene-α-olefin copolymer in a specific amount, the neck-in phenomenon at the time of melt extrusion molding with a T-die type extruder or the like is improved, the blocking resistance is also excellent, and as an elastic material. Not only can high-productivity molded products such as films and sheets having very suitable mechanical performance be produced, but also thickness unevenness and cracks are less likely to occur when melt-molded with an inflation molding machine,
The present inventors have found that a high quality molded product can be manufactured with high productivity, and have completed the present invention.

That is, the present invention provides (i) a thermoplastic polyurethane composition comprising a thermoplastic polyurethane (a), a thermoplastic polyurethane (b) and an ethylene-α-olefin copolymer (c); A) the thermoplastic polyurethane (a) has a number of hydroxyl groups per molecule of 2.01 to 2.10 and a number average molecular weight of from 500 to 8,000, a high molecular weight polyol unit;
A thermoplastic polyurethane comprising an organic diisocyanate unit and a chain extender unit and having a nitrogen atom content of 2.5% by weight or less; (iii) the thermoplastic polyurethane (b) has a number average molecular weight of 1,500 to 5, 2,000 polyester diol units, organic diisocyanate units and chain extender units, having a nitrogen atom content of 2.6% by weight or more, and an endothermic peak in the range of 200 to 220 ° C. by differential scanning calorimetry (DSC). A thermoplastic polyurethane having a enthalpy of crystallization (ΔH) of 2 to 15 J / g as determined from the endothermic peak; and (iv) the total weight of the thermoplastic polyurethane (a) and the thermoplastic polyurethane (b) 40 to 80% by weight of thermoplastic polyurethane (a) and 60 to 20% by weight of thermoplastic polyurethane (b) based on And that a thermoplastic polyurethane composition characterized that ethylene -α- olefin copolymer (c) in a proportion of 5 to 250 wt%. Further, the present invention is a molded article such as a film or a sheet comprising the thermoplastic polyurethane composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic polyurethane (a) used in the present invention is composed of a polymer polyol unit, an organic diisocyanate unit and a chain extender unit. Further, the thermoplastic polyurethane (b) used in the present invention
Is composed of a polyesterdiol unit, an organic diisocyanate unit and a chain extender unit.

Examples of the polymer polyol unit constituting the thermoplastic polyurethane (a) include polyester polyol, polyether polyol, polycarbonate polyol, polyester polycarbonate polyol and the like. These polymer polyols may be used alone or in combination of two or more. Among these, it is preferable to use a polyester polyol or a polyether polyol, and it is more preferable to use a polyester polyol.

The above polyester polyol is subjected, for example, to a direct esterification reaction or transesterification reaction between the polyol and a polycarboxylic acid or an ester-forming derivative thereof such as an ester or an anhydride according to a conventional method,
Alternatively, it can be produced by ring-opening polymerization of a lactone using a polyol or the like as an initiator.

As the polyol constituting the polyester polyol, those generally used in the production of polyester can be used. For example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol , 2-methyl-1,3-propanediol, 2,
2-diethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-
1,4-butanediol, neopentyl glycol,
1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1 , 8-octanediol,
Aliphatic diols having 2 to 15 carbon atoms such as 1,9-nonanediol, 2-methyl-1,9-nonanediol, 2,8-dimethyl-1,9-nonanediol, and 1,10-decanediol; 1 Alicyclic diols such as 1,4-cyclohexanediol, cyclohexanedimethanol, cyclooctanedimethanol and dimethylcyclooctanedimethanol; one molecule such as aromatic dihydric alcohols such as 1,4-bis (β-hydroxyethoxy) benzene Diols having two hydroxyl groups per molecule; and trimethylolpropane, trimethylolethane, glycerin, 1,2,2
Examples thereof include polyols having three or more hydroxyl groups per molecule, such as 6-hexanetriol, pentaerythritol, diglycerin, and methylglycoxide. These polyols may be used alone or in combination of two or more. Among them, 2-methyl-1,4
-Butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7
-Dimethyl-1,8-octanediol, 2-methyl-
1,9-nonanediol, 2,8-dimethyl-1,9-
It is preferable to use an aliphatic diol having 5 to 12 carbon atoms having a methyl group as a side chain such as nonanediol, and it is more preferable to use these aliphatic diols in a proportion of 30 mol% or more based on the total amount of the polyol. More preferably, 5
More preferably, it is used in a proportion of 0 mol% or more. In addition, it is preferable to use a small amount of trimethylolpropane from the viewpoint that a thermoplastic polyurethane composition having excellent performance such as flexibility can be obtained.

As the polycarboxylic acid constituting the polyester polyol, those generally used in the production of polyester can be used. For example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid Acid, sebacic acid, dodecandioic acid, methyl succinic acid, 2-methylglutaric acid, 3-methylglutaric acid, trimethyladipic acid, 2-methyloctanedioic acid, 3,8-dimethyldecandioic acid, 3,7-dimethyldecane An aliphatic dicarboxylic acid having 4 to 12 carbon atoms such as a diacid;
Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid; trifunctional or higher polycarboxylic acids such as trimellitic acid and pyromellitic acid; . These polycarboxylic acids may be used alone or in combination of two or more.
Among these, it is preferable to use a fatty acid dicarboxylic acid having 6 to 12 carbon atoms, and it is more preferable to use adipic acid, azelaic acid, and sebacic acid.

Examples of the lactone include ε-caprolactone and β-methyl-δ-valerolactone.

Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and poly (methyltetraethylene glycol) obtained by ring-opening polymerization of a cyclic ether, preferably in the presence of a small amount of a trifunctional or higher polyol. Methylene glycol)
And the like, and one or more of these can be used. Among these, it is preferable to use polytetramethylene glycol.

As the polycarbonate polyol, for example, those obtained by reacting a polyol with a carbonate compound such as dialkyl carbonate, alkylene carbonate and diaryl carbonate can be used. As the polyol constituting the polycarbonate polyol, the polyol exemplified above as the constituent component of the polyester polyol can be used. Also, as the dialkyl carbonate, dimethyl carbonate,
Diethyl carbonate and the like. Further, the alkylene carbonate includes ethylene carbonate, and the diaryl carbonate includes diphenyl carbonate.

The polyester polycarbonate polyol can be obtained, for example, by simultaneously reacting a polyol, a polycarboxylic acid and a carbonate compound.
Alternatively, it can be obtained by previously synthesizing a polyester polyol and a polycarbonate polyol by the above-mentioned method, and then reacting them with a carbonate compound or with a polyol and a polycarboxylic acid.

The high molecular weight polyol constituting the thermoplastic polyurethane (a) has a number of hydroxyl groups per molecule of 2.01.
２．１2.10 and 2.01
More preferably within a range of 2.07 to 2.07.
More preferably, it is in the range of 1-2.05. By using a polymer polyol having a hydroxyl group number per molecule within the above range, the neck-in phenomenon that occurs when a molded article such as a film or sheet is melt-extruded by a T-die type extruder or the like is further improved. Not only is the productivity of the molded product further improved, but even if the molded product such as a film or sheet extruded from the T-die is taken at a high speed,
Defective phenomena such as necking and cracks are less likely to occur. Further, a molded article such as a film or sheet having a small thickness, a good surface condition, and excellent elasticity can be obtained.

Examples of the high molecular polyol constituting the thermoplastic polyurethane (a) include, among the raw material components of the high molecular polyol described above, a component having two functional groups in one molecule and a functional group in one molecule. And a component having three or more hydroxyl groups per molecule of the high molecular polyol.
The polymer polyol produced by using the compound in such a ratio as to be 01 to 2.10 may be used alone, or a polymer diol having 2 hydroxyl groups per molecule and a hydroxyl group per molecule may be used. May be used as a mixture of a polymer polyol having a value of greater than 2 and a ratio of the number of hydroxyl groups per molecule of the polymer polyol being 2.01 to 2.10.

The number average molecular weight of the high molecular polyol is 500
8,000, preferably 600-5,000, and more preferably 800-5,000. By using a polymer polyol having a number average molecular weight within this range, a thermoplastic polyurethane composition having more excellent mechanical performance and melt moldability can be obtained. In addition,
The number average molecular weight of the high molecular polyol referred to in the present specification is a number average molecular weight calculated based on a hydroxyl value measured according to JIS K-1577.

As the polyester diol constituting the thermoplastic polyurethane (b), for example, a diol and an ester-forming derivative such as a dicarboxylic acid or an ester or an anhydride thereof are directly subjected to an esterification reaction or a transesterification reaction according to a conventional method. Or by subjecting a lactone to ring-opening polymerization using a diol or the like as an initiator.

As the diol constituting the polyester diol, those generally used in the production of polyester can be used. Examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and 1,3-propanediol. , 2-methyl-1,3-propanediol, 2,2-
Diethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,
4-butanediol, neopentyl glycol, 1,5
-Pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol,
2,7-dimethyl-1,8-octanediol, 1,9
-Nonanediol, 2-methyl-1,9-nonanediol, 2,8-dimethyl-1,9-nonanediol, 1,
Aliphatic diols having 2 to 15 carbon atoms such as 10-decanediol; alicyclic diols such as 1,4-cyclohexanediol, cyclohexanedimethanol, cyclooctanedimethanol, dimethylcyclooctanedimethanol; 1,4-bis ( Examples thereof include diols having two hydroxyl groups per molecule such as aromatic dihydric alcohols such as β-hydroxyethoxy) benzene. These diols may be used alone or in combination of two or more. Among these, 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,4-butanediol,
Methyl-1,8-octanediol, 2-methyl-1,
Use is made of an aliphatic diol having 5 to 12 carbon atoms having a methyl group as a side chain, such as 9-nonanediol, 2,7-dimethyl-1,8-octanediol and 2,8-dimethyl-1,9-nonanediol. Preferably, these aliphatic diols are added in an amount of 30 mol% based on the total amount of
It is more preferably used in the above ratio, and further preferably used in a ratio of 50 mol% or more.

As the dicarboxylic acid constituting the polyester diol, those generally used in the production of polyester can be used. For example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid , Sebacic acid, dodecanedioic acid, methylsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, trimethyladipic acid, 2-methyloctanedioic acid,
Aliphatic dicarboxylic acids having 4 to 12 carbon atoms such as 3,8-dimethyldecandioic acid and 3,7-dimethyldecandioic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, orthophthalic acid; And aromatic dicarboxylic acids such as naphthalenedicarboxylic acid. These dicarboxylic acids may be used alone or in combination of two or more. Among these, it is preferable to use a fatty acid dicarboxylic acid having 6 to 12 carbon atoms, and it is more preferable to use adipic acid, azelaic acid, and sebacic acid.

Examples of the lactone include ε-caprolactone and β-methyl-δ-valerolactone.

The number average molecular weight of the polyester diol constituting the thermoplastic polyurethane (b) is from 1,500 to 5,
000, preferably from 1,800 to 4,000. By using a polyester diol having a number average molecular weight within this range, a thermoplastic polyurethane composition having more excellent mechanical performance and melt moldability can be obtained.

Thermoplastic polyurethanes (a) and (b)
There is no particular limitation on the organic diisocyanate used in the production of the thermoplastic polyurethane, and any organic diisocyanate conventionally used in the production of ordinary thermoplastic polyurethanes may be used. For example, 4,4′-diphenylmethane diisocyanate, tri Range isocyanate, phenylene diisocyanate, xylylene diisocyanate,
1,5-naphthylene diisocyanate, 3,3′-dichloro-4,4′-diphenylmethane diisocyanate,
Aromatic diisocyanates such as tolylene diisocyanate; aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate. These organic diisocyanates may be used alone or in combination of two or more. Among these, it is preferable to use 4,4'-diphenylmethane diisocyanate.

Thermoplastic polyurethanes (a) and (b)
There is no particular limitation on the chain extender used in the production of
Any of the chain extenders conventionally used in the production of ordinary thermoplastic polyurethanes may be used, and low molecular weight compounds having a molecular weight of 300 or less and having two or more active hydrogen atoms capable of reacting with isocyanate groups in the molecule. It is preferable to use For example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate And diols such as xylylene glycol; diamines such as hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine and derivatives thereof, phenylenediamine, tolylenediamine, xylenediamine, adipic dihydrazide, and isophthalic dihydrazide; Examples include amino alcohols such as aminoethyl alcohol and aminopropyl alcohol. These low molecular compounds may be used alone or in combination of two or more. Among them, those having 2 to 10 carbon atoms
It is preferable to use an aliphatic diol, and more preferable to use 1,4-butanediol.

The above-mentioned polymer polyol or polyester diol is reacted with an organic diisocyanate and a chain extender to form a thermoplastic polyurethane (a) or (b).
In producing, the mixing ratio of each component is appropriately determined in consideration of the hardness to be imparted to the intended thermoplastic polyurethane and the like, but the polymer polyol or polyester diol and the chain extender have It is preferable to use each component in such a ratio that the isocyanate group contained in the organic diisocyanate is 0.9 to 1.2 mol per 1 mol of active hydrogen atoms. The use of each component at the above ratio is preferable because a thermoplastic polyurethane composition excellent in melt moldability, blocking resistance, elastic recovery and the like can be obtained.

Thermoplastic polyurethanes (a) and (b)
The production method is not particularly limited, using the above-mentioned polymer polyol or polyester diol, an organic diisocyanate and a chain extender, utilizing a known urethanation reaction technique, a prepolymer method and a one-shot method. Any of them may be manufactured. Among these, it is preferable to carry out melt polymerization substantially in the absence of a solvent, and it is more preferable to employ a continuous melt polymerization method using a multi-screw extruder.

The nitrogen content of the thermoplastic polyurethane (a) is at most 2.5% by weight, preferably from 1.0 to 2.5% by weight, more preferably from 1.5 to 2.5% by weight. More preferably, it is 1.7 to 2.5% by weight. When the nitrogen content of the thermoplastic polyurethane (a) is more than 2.5% by weight, the resulting thermoplastic polyurethane composition has a high hardness, and has a high elastic recovery property such as a stretchable film or sheet. Molded products cannot be obtained.

The nitrogen content of the thermoplastic polyurethane (b) is at least 2.6% by weight, preferably 2.6 to 6.0% by weight, and preferably 2.8 to 5.0% by weight. More preferably, the content is 3.0 to 4.0% by weight. If the nitrogen content of the thermoplastic polyurethane (b) is less than 2.6% by weight, the resulting thermoplastic polyurethane composition will have poor melt moldability and blocking resistance.

The logarithmic viscosity of the thermoplastic polyurethane (a) is determined by dissolving the thermoplastic polyurethane (a) in an N, N-dimethylformamide solution to a concentration of 0.5 g / dl and measuring at 30 ° C. It is preferably at least 0.8 dl / g, more preferably at least 0.9 dl / g, even more preferably at least 1.0 dl / g. When the thermoplastic polyurethane (a) having the logarithmic viscosity in the above range is used, a thermoplastic polyurethane composition which gives a molded article with less residual strain can be obtained.

The logarithmic viscosity of the thermoplastic polyurethane (b) is determined by dissolving the thermoplastic polyurethane (b) in an N, N-dimethylformamide solution to a concentration of 0.5 g / dl and measuring at 30 ° C. 0.2 to 1.2 dl / g
Is preferably 0.3 to 1.1 dl / g, and more preferably 0.5 to 1.1 dl / g. When the thermoplastic polyurethane (b) having the logarithmic viscosity in the above range is used, a thermoplastic polyurethane composition having more excellent melt moldability and blocking resistance can be obtained.

The thermoplastic polyurethane (b) shows an endothermic peak in the range of 200 to 220 ° C. by differential scanning calorimetry (DSC), and has a crystallization enthalpy (ΔH) determined from this endothermic peak of 2 to 15 J / g. And preferably 3 to 10 J / g. When the temperature of the endothermic peak is less than 200 ° C., or when the crystallization enthalpy (ΔH) is less than 2 J / g, the resulting thermoplastic polyurethane composition has poor extrusion moldability and blocking resistance. On the other hand, when the endothermic peak temperature exceeds 220 ° C. or the crystallization enthalpy (ΔH) exceeds 15 J / g, an unmelted substance is liable to be generated in the obtained thermoplastic polyurethane composition, and a film, a sheet, etc. When molding into a molded article of the above, bumps are likely to occur. Also, the blocking resistance is poor.

Ethylene-α-olefin copolymer (c)
Is composed of an ethylene unit and an α-olefin unit. Examples of the α-olefin unit constituting the ethylene-α-olefin copolymer (c) include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, -Units derived from octadecene and the like. These α-olefin units may be contained alone or in combination of two or more. Among them, a unit derived from an α-olefin having 4 or more carbon atoms is preferable, and an α-olefin having 7 to 12 carbon atoms is preferable because recovery performance such as recovery stress or residual strain after elongation is more excellent. Units derived from olefins are more preferred, units derived from α-olefins having 7 to 10 carbon atoms are more preferred, and units derived from 1-hexene or 1-octene are particularly preferred. Further, a small amount of a non-conjugated diene unit can be used together with the above-mentioned α-olefin unit, if necessary. Examples of the non-conjugated diene unit include units derived from ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene, methylene norbornene, and the like.

Ethylene-α-olefin copolymer (c)
Is a molar ratio of ethylene units / α-olefin units = 55/45 to 55/45.
99/1, preferably 75/25 to 95/5
Is more preferable, and it is still more preferable that it is 85/15 to 95/5. When the content of ethylene units is 55
When the amount is less than mol%, the softening temperature of the ethylene-α-olefin copolymer becomes low, and it becomes difficult to uniformly mix with the thermoplastic polyurethanes (a) and (b). When a copolymer is used, the film obtained from the thermoplastic polyurethane composition tends to stick easily. Furthermore, when melt extrusion molding, the range of thickness unevenness that occurs at both ends of molded products such as films and sheets due to neck-in phenomenon increases, and when inflation molding, defective phenomena such as uneven thickness and cracks May occur, and the productivity of the product tends to decrease. On the other hand, if the ethylene unit content is 9
When an ethylene-α-olefin copolymer exceeding 9 mol% is used, it tends to be difficult to obtain a film having a small thickness and excellent elasticity.

Ethylene-α-olefin copolymer (c)
The melt index measured at 190 ° C. under a load of 2.16 kg is preferably from 0.1 to 12 g / 10 min, more preferably from 0.2 to 7 g / 10 min, and preferably from 0.4 to 7 g / 10 min. More preferably, it is 5 g / 10 minutes. When the ethylene-α-olefin copolymer (c) having a melt index in the above range is used, it is excellent in melt moldability when producing a film or a sheet, a thin film can be achieved, blocking resistance, and after elongation. A material having better recovery performance such as recovery stress and residual strain can be obtained. In addition,
The melt index of the ethylene-α-olefin copolymer (c) referred to in the present specification is ASTM D-123.
It is a value measured according to 8.

Ethylene-α-olefin copolymer (c)
Is preferably in the range of 30 to 90, more preferably in the range of 40 to 85. Ethylene-α having a Shore A hardness in the above range
-When the olefin copolymer (c) is used, it is possible to obtain a thermoplastic polyurethane composition and a molded article obtained therefrom which have more excellent elastic recovery and mechanical performance. The Shore A hardness of the ethylene-α-olefin copolymer (c) referred to in this specification is ASTM D-22.
It is a value measured according to No. 40.

Ethylene-α-olefin copolymer (c)
The density is preferably 0.85~0.93g / cm ^3, more preferably from 0.86~0.91g / cm ^3, in the range of 0.86~0.90g / cm ³ Is more preferred. Ethylene-α having a density in the above range
The use of the olefin copolymer (c) is preferable because a product having more excellent recovery properties such as melt extrusion moldability, blocking resistance, and residual strain can be obtained. In addition, the density referred to in the present specification is a value measured in accordance with ASTM D-792.

Ethylene-α-olefin copolymer (c)
Preferably, the Mooney viscosity measured at 100 ° C. using an L-shaped rotor is 5 to 70 ML _{1 + 4} (100 ° C.), more preferably 10 to 55 ML _{1 +4} (100 ° C.). When the ethylene-α-olefin copolymer (c) having the Mooney viscosity in the above range is used, those having more excellent melt extrusion moldability, blocking resistance, recovery performance after elongation recovery stress and residual strain, and the like can be obtained. can get. In addition,
The Mooney viscosity of the ethylene-α-olefin copolymer (c) referred to in the present specification is a value measured according to ASTM D-1646.

Ethylene-α-olefin copolymer (c)
The production method of is not particularly limited, the above monomers, for example, by a known method such as a solution polymerization method, a bulk polymerization method, and a gas phase polymerization method, usually at a temperature of 0 to 250 ° C. and a normal pressure to 1000 It is obtained by polymerization at atmospheric pressure (100 MPa). In the polymerization, it is preferable to use a single-site catalyst having a uniform polymerization active point, since a polymer having a narrow molecular weight distribution and a narrow copolymer composition distribution can be easily obtained. Among the single-site catalysts, metallocene compounds containing a tetravalent transition metal are particularly preferable. For example, cyclopentadienyltitanium tris (dimethylamide), methylcyclopentadienyltitanium tris (dimethylamide), bis (cyclopentadiene) Enyl) titanium dichloride, dimethylsilyltetramethylcyclopentadienyl-t-
Butylamidozirconium dichloride, dimethylsilyltetramethylcyclopentadienyl-t-butylamidohafnium dichloride, dimethylsilyltetramethylcyclopentadienyl-pn-butylphenylamidozirconium dichloride, methylphenylsilyltetramethylcyclopentadienyl- t-butylamide hafnium dichloride, (t-butylamide) (tetramethyl-
Cyclopentadienyl) -1,2-ethanediyltitanium dichloride, indenyl titanium tris (dimethylamide), indenyl titanium tris (diethylamide), indenyl titanium bis (di-n-butylamide) (di-n-propylamide ). When a metallocene compound is used as a polymerization catalyst, since polymerization activity is not exhibited by itself, a co-catalyst such as methylaluminoxane or a non-coordinating boron compound is used in an amount of 2 to 1,000,000 per mole of the metallocene compound. 2,000 mol, preferably 50 to 5,000 mol, in combination.

The thermoplastic polyurethane composition of the present invention comprises:
Based on the total weight of the thermoplastic polyurethane (a) and the thermoplastic polyurethane (b), the thermoplastic polyurethane (a) is contained in a proportion of 40 to 80% by weight, and the thermoplastic polyurethane (b) is contained in a proportion of 60 to 20% by weight. It is necessary that the thermoplastic polyurethane (a) is 45-75.
It is preferable that the thermoplastic polyurethane (b) is contained at a ratio of 55 to 25% by weight. When the content of the thermoplastic polyurethane (a) is less than 40% by weight (when the content of the thermoplastic polyurethane (b) exceeds 60% by weight), the hardness of the thermoplastic polyurethane composition becomes high, so that the However, it is difficult to obtain a thin film and a good surface condition of the film or sheet, and the resulting film or sheet has poor elastic recovery. On the other hand, when the content of the thermoplastic polyurethane (a) exceeds 80% by weight [the content of the thermoplastic polyurethane (b) is
% By weight], the neck-in phenomenon that occurs when melt extruding a film or sheet with a T-die extruder or the like is not sufficiently improved, and both ends of a molded article such as a film or sheet are not improved. The range of the thickness unevenness generated in the portion becomes wide, and the productivity of a uniform product obtained by trimming the portion of the thickness unevenness decreases. Further, when performing inflation molding, defective phenomena such as uneven thickness and cracks are not sufficiently improved, and the productivity of a homogeneous product is reduced. Furthermore, the blocking resistance of a molded product obtained by melt extrusion molding, inflation molding or the like is also poor.

Ethylene-α-olefin copolymer (c)
Is in the range of 5 to 250% by weight, and preferably in the range of 20 to 180% by weight, based on the total weight of the thermoplastic polyurethane (a) and the thermoplastic polyurethane (b). When the content of the ethylene-α-olefin copolymer (c) is less than 5% by weight, the blocking resistance and the strength of the obtained molded product are inferior. On the other hand, when the content ratio of the ethylene-α-olefin copolymer (c) is 25
When the amount exceeds 0% by weight, the strength of the obtained molded product is inferior.

The thermoplastic polyurethane composition of the present invention comprises:
The above-mentioned thermoplastic polyurethane composition comprising the thermoplastic polyurethane (a), the thermoplastic polyurethane (b) and the ethylene-α-olefin copolymer (c) is further provided with a bisamide compound (d) and a thermoplastic polyurethane (a).
And preferably 0.05 to 8% by weight, more preferably 0.05 to 8% by weight, and still more preferably 0.1 to 6% by weight based on the total weight of the thermoplastic polyurethane (b). %.
By containing the bisamide compound (d) at the above ratio, a thermoplastic polyurethane composition with further improved blocking resistance and releasability can be obtained.

As the bisamide compound (d), for example, bisamide compounds represented by the following general formulas (1) and (2) are preferable. R ¹ -CONH-R ² -NHCO-R ³ (1) (wherein, R ¹ and R ³ each represent an alkyl group or an alkenyl group, and R ² represents an alkylene group or an arylene group.) R ⁴ -NHCO —R ⁵ —CONH—R ⁶ (2) (wherein, R ⁴ and R ⁶ each represent an alkyl group or an alkenyl group, and R ⁵ represents an alkylene group or an arylene group.) In the above general formula (1), , R ¹ and R ³ have 6 to ³ carbon atoms
More preferably, R 5 is an alkyl or alkenyl group having 5 and R ² is an alkylene group or an arylene group having 2 to 12 carbon atoms. In the above general formula (2), R ⁴ and R ⁶
Is an alkyl or alkenyl group having 6 to 35 carbon atoms,
More preferably, R ⁵ is an alkylene group or an arylene group having 2 to 12 carbon atoms.

The bisamide compound represented by the general formula (1) is a compound obtained from an aliphatic monocarboxylic acid and a diamine, and among them, an aliphatic monocarboxylic acid having 6 to 35 carbon atoms and a C2 to C2 compound. Compounds derived from a diamine of 12 are more preferable, and specific examples thereof include methylene bisstearic acid amide, ethylenebiscaprylic amide, ethylenebiscapric amide, ethylenebislauric amide, ethylenebismyristic amide, and ethylene Bispalmitic acid amide, ethylenebisstearic acid amide, ethylenebisisostearic acid amide, ethylenebisbehenic acid amide, ethylenebismontanamide, tetramethylenebisstearic acid amide,
Tetramethylenebisisostearic acid amide, tetramethylenebismontanamide, hexamethylenebiscaprylic amide, hexamethylenebiscapric amide,
Hexamethylene bislaurate amide, hexamethylene bismyristate amide, hexamethylene bispalmitate amide, hexamethylene bis stearamide,
Hexamethylenebisisostearamide, Hexamethylenebisbehenamide, Hexamethylenebismontanamide, Ethylenebisoleamide, Ethylenebiserucamide, Tetramethylenebisoleamide, Tetramethylenebiserucamide, Hexamethylenebis Oleic acid amide, m-xylylenebisstearic acid amide, m-xylenebismontanamide and the like can be mentioned.

The bisamide compound represented by the general formula (2) is a compound obtained from an aliphatic monoamine and a dicarboxylic acid, and among them, an aliphatic monoamine having 6 to 35 carbon atoms and a dicarboxylic acid having 2 to 12 carbon atoms. Compounds derived from acids are more preferable, and specific examples thereof include:
N, N'-distearyl adipamide, N, N'-
Distearyl sebacamide, N, N'-distearyl azelaic amide, N, N'-dioleyl adipamide, N, N'-dioleyl sebacamide,
N, N'-dioleyl azelaic acid amide, N, N'-
Distearyl isophthalamide, N, N'-dioleyl isophthalamide and the like can be mentioned.

The bisamide compounds represented by the above general formulas (1) and (2) may be used alone or in combination of two or more.

The thermoplastic polyurethane composition of the present invention comprises:
To the thermoplastic polyurethane composition comprising the thermoplastic polyurethane (a), the thermoplastic polyurethane (b) and the ethylene-α-olefin copolymer (c), a polyolefin resin (e) is further added with a thermoplastic polyurethane (a). ) And the thermoplastic polyurethane (b), preferably in a proportion of 3 to 25% by weight, more preferably in a proportion of 5 to 17% by weight.
By blending the polyolefin-based resin (e) at the above ratio, a resin having more excellent blocking resistance and melt moldability can be obtained.

Examples of the polyolefin-based resin (e) include high-density polyethylene, medium-density polyethylene, low-density polyethylene, polypropylene, and polybutylene. These polyolefin resins may be used alone or in combination of two or more. Among these, it is more preferable to use a high-density polyethylene having a density in the range of 0.93 to 0.97 g / cm ³ .
In addition, the density of the polyolefin-based resin referred to in this specification,
It is a value measured according to ASTM D-1505.

190 ° C. of the polyolefin resin (e),
The melt index measured under a 2.16 kg load is
It is preferably 0.01 to 0.3 g / 10 minutes,
More preferably, it is 0.03 to 0.2 g / 10 minutes.

The thermoplastic polyurethane composition of the present invention contains a reinforcing agent, a coloring agent, a lubricant, a flame retardant, an ultraviolet absorber, an antioxidant, and a hydrolysis resistance improver as long as the effects of the present invention are not impaired. , Fungicides, antibacterial agents, stabilizers and other additives; glass fibers, polyester fibers and other fibers;
Inorganic substances such as talc, silica and the like; optional components such as various coupling agents can be blended as required.

The thermoplastic polyurethane composition of the present invention comprises:
The above-mentioned thermoplastic polyurethane (a), thermoplastic polyurethane (b), ethylene-α-olefin copolymer (c)
It can be produced by mixing other components as required and in a desired manner. For example, a thermoplastic polyurethane (a), a thermoplastic polyurethane (b), an ethylene-α-olefin copolymer (c) and a thermoplastic polyurethane (a), using a vertical or horizontal mixer as generally used for mixing resin materials. After pre-mixing the other components at a predetermined ratio as necessary, by using a single-screw or twin-screw extruder, mixing roll, Banbury mixer, etc., melt-kneading in a batch or continuous manner under heating Can be manufactured.

The thermoplastic polyurethane composition of the present invention comprises:
Melt molding is possible, and various molded articles can be produced smoothly by any molding method such as extrusion molding, inflation molding, injection molding, blow molding, calendar molding, and casting. In particular, since the thermoplastic polyurethane composition of the present invention is excellent in melt moldability, for example, in a melt extrusion molding of a film or a sheet by a T-die extruder, the composition was extruded from the effective width of the T-die. The neck-in phenomenon in which the width of molded products such as films and sheets is considerably reduced has been significantly improved, and the range of thickness unevenness at both ends of molded products such as films and sheets caused by the neck-in phenomenon is narrowed, The productivity of a product obtained by trimming the thickness unevenness portion is improved. Also, when a molded product such as a film or a sheet extruded from a T-die is taken at a high speed, the entire molded product such as a film or a sheet is not uniformly stretched and necking or cracking which causes constriction. As a result, high quality products can be obtained with high productivity. Further, also in the molding of films and sheets by an inflation molding machine, defective phenomena such as uneven thickness and cracks of the obtained molded product are remarkably improved, and a high-quality molded product can be obtained with high productivity. Furthermore, molded articles such as films and sheets obtained by using the thermoplastic polyurethane composition of the present invention have appropriate strength, recovery performance such as recovery stress or residual strain after elongation, tensile breaking strength and tensile breaking. It has excellent mechanical performance represented by elongation and the like, and has a smooth surface and good surface condition. In particular, it is excellent in recovery performance such as recovery stress and residual strain after elongation.
It is particularly preferable to use it for stretchable films used for disposable diapers, sanitary napkins, seals, dust proofing and the like. Further, it can be used for various uses such as sheet use for general-purpose conveyor belts, various keyboard sheets, laminated products, various containers, and the like. Furthermore, the film or sheet made of the thermoplastic polyurethane composition of the present invention has excellent adhesiveness with a fibrous substrate made of nonwoven fabric or other fiber cloth, or a substrate made of another polymer film or sheet. Therefore, it is suitable for manufacturing a laminate. For example, the thermoplastic polyurethane composition of the present invention can be melt-extruded into a film or a sheet on a fibrous substrate or another substrate to produce a laminate.

[0056]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In Examples and Comparative Examples, the nitrogen atom content, logarithmic viscosity, and differential scanning calorimetry (DS
C), melt extrusion moldability, film production state, surface state, blocking resistance, 100% modulus (M10
0), residual strain, adhesiveness and inflation moldability were measured or evaluated by the following methods.

[Nitrogen atom content] It was determined by elemental analysis of thermoplastic polyurethane using an elemental analyzer (Model 240-2, manufactured by PerkinElmer).

[Logarithmic viscosity] A thermoplastic polyurethane was added to an N, N-dimethylformamide solution at a concentration of 0.5 g / dl.
The polyurethane solution was dissolved using an Ubbelohde viscometer and the flow time at 30 ° C. was measured.
The logarithmic viscosity was determined by the following equation. Logarithmic viscosity = [ln (t / t ₀ )] / c [where t is the flow time (seconds) of the polyurethane solution, t ₀
Represents the flow time (second) of the solvent, and c represents the concentration (g / dl) of the polyurethane solution. ]

[Differential Scanning Calorimetry (DSC)] The enthalpy of fusion of the thermoplastic polyurethane was measured using a differential scanning calorimeter (DSC30 manufactured by Mettler). 10 mg of thermoplastic polyurethane was used for the measurement, and the temperature was measured at a rate of 10 ° C./min in a nitrogen gas atmosphere. The crystallization enthalpy (ΔH) was determined from the endothermic peak temperature and the endothermic peak area in the range of 200 to 220 ° C. I asked.

[Melt Extrusion Formability] While discharging the film extruded from the T-die type extruder, the film width 10 cm below the T-die exit was measured, and the neck-in rate (%) was determined according to the following equation. , And an index of melt extrusion moldability. The smaller this value is, the more the neck-in phenomenon is improved,
It shows that it has excellent melt extrusion moldability. Neck-in rate (%) = (W ₂ −W ₁ ) / W ₂ × 100 (where W ₁ represents a film width 10 cm below the T-die exit, and W ₂ represents an effective width of the T-die. )

[Film production state, surface state] A film cooled by being extruded from a T-die type extruder onto a cooling roll at 30 ° C. is wound at a winding speed of about 3 m / min without using release paper. I took it. During the winding, the production state of the film was observed and evaluated according to the following criteria. ：: Without causing a defect phenomenon such as cracking in the film,
Can be wound up normally. Δ: The film could be wound up although some defects such as cracks occurred in the film. X: A defective phenomenon such as a crack occurred in the film, and the film could not be wound. Furthermore, observe the surface condition of the wound film,
平滑 indicates a smooth surface, and X indicates an uneven surface due to poor dispersion.

[Blocking Resistance] A film extruded and cooled from a T-die type extruder onto a cooling roll at 30 ° C. was wound at a winding speed of about 3 m / min without using release paper. After leaving the wound film at room temperature for 24 hours, the film was rewound by hand, and the resistance at that time was evaluated according to the following criteria. ◎: Rewinding is extremely easy without requiring any tensile force. ：: Can be smoothly rewound. Δ: A considerable tensile force was required, but rewinding was possible. X: The adhesive property is large and rewinding is impossible.

[100% Modulus (M100) and Residual Strain] A test piece (20 cm × 5 cm) was prepared from a 30 μm thick film formed using a T-die type extruder. This test piece was subjected to an autograph measuring device IS-
Using a 500D (manufactured by Shimadzu Corporation), 100% elongation was performed at room temperature at a tensile speed of 300 mm / min, and the 100% modulus (M100) was measured. Next, it is returned to the position before elongation at a speed of 300 mm / min (first cycle), and after elongating 100% at the same speed continuously, the residual strain at the time when it is returned to the position before elongation (second cycle) is obtained. Was. The lower the value of the 100% modulus (M100), the lower the stress and the higher the elongation. In addition, the smaller the value of the residual strain, the better the recovery performance that returns to the original state after elongation.

[Adhesiveness] A test piece having a width of 25 mm was prepared from a film having a thickness of 30 μm by using a T-die type extruder. An adhesive tape (manufactured by Nichiban Co., Ltd., cloth adhesive tape LS No. 101) is attached to the test piece, and the resistance value when the adhesive tape is peeled off is measured using an autograph measuring device IS-500D (manufactured by Shimadzu Corporation). Then, it was measured at room temperature under the condition of a tensile speed of 300 mm / min, and was used as an index of the adhesiveness to the substrate.

[Inflation Formability] A single screw extruder (50 mmφ, cylinder temperature: 170-200 ° C., die temperature: 200) equipped with an inflation die.
C)), and while the film was extruded in a tube shape in the vertical direction, the film was continuously wound for 2 hours at a winding speed of about 8 m / min. The state of film production was observed and evaluated according to the following criteria. ：: The film can be wound up normally without causing defects such as uneven thickness and cracks in the film. Δ: The film was somewhat defective, such as uneven thickness and cracks, but could be wound up. ×: Inferior phenomena such as uneven thickness and cracks occurred on the film, and winding was impossible.

Abbreviations relating to the resins and compounds used in the following Examples and Comparative Examples are shown below.

TPU-a1 : 1 produced by reacting 3-methyl-1,5-pentanediol with adipic acid
A polyester diol having a number of hydroxyl groups per molecule of 2.00 and a number average molecular weight of 3500 (hereinafter referred to as “polyester diol (1)”);
The number of hydroxyl groups per molecule produced by reacting -methyl-1,5-pentanediol, trimethylolpropane and adipic acid is 3.00, and the number average molecular weight is 2
A mixture of polyester polyol (hereinafter, referred to as "polyester polyol (2)") having a molar ratio of 98/2 polyester diol (1) / polyester polyol (2) of 2 and a hydroxyl number per molecule of 2 .02] with 4,4′-diphenylmethane diisocyanate and 1,4-butanediol to obtain a thermoplastic polyurethane [having a nitrogen atom content of 2.4.
% By weight, logarithmic viscosity is 1.25 dl / g]

TPU-a2 : a mixture of polyester diol (1) and polyester polyol (2) [molar ratio of polyester diol (1) / polyester polyol (2) is 95/5, and the number of hydroxyl groups per molecule is 2.05 Is reacted with 4,4'-diphenylmethane diisocyanate and 1,4-butanediol to obtain a thermoplastic polyurethane having a nitrogen atom content of 1.9% by weight and a logarithmic viscosity of 1.20 dl / g.

TPU-a3 : 2,7-dimethyl-1,8
A mixture of octanediol and 2,8-dimethyl-1,9-nonanediol (at a molar ratio of 35/65) and adipic acid, the number of hydroxyl groups per molecule being 2.00, Polyester diol having an average molecular weight of 2000 (hereinafter referred to as "polyester diol (3)") and polyester polyol (2)
[Polyester diol (3) / polyester polyol (2) molar ratio of 97/3, number of hydroxyl groups per molecule is 2.03] with 4,4′-diphenylmethane diisocyanate and 1,4-butanediol [The nitrogen atom content is 2.2% by weight and the logarithmic viscosity is 1.31 dl / g]

TPU-a4 : a mixture of polyester diol (1) and polyester polyol (2) [polyester diol (1) / polyester polyol (2) molar ratio is 88/12, and the number of hydroxyl groups per molecule is 2.12 Is reacted with 4,4'-diphenylmethane diisocyanate and 1,4-butanediol to obtain a thermoplastic polyurethane having a nitrogen atom content of 2.4.
Wt%, insoluble in DMF solvent]

TPU-b1 : polyester diol (1) / 4,4′-diphenylmethane diisocyanate / 1,4-butanediol-based thermoplastic polyurethane [nitrogen atom content: 3.2% by weight, differential scanning calorimetry (DS)
Endothermic peak temperature of 204 ° C., crystallization enthalpy (ΔH) 3.5 J / g, logarithmic viscosity 0.74 dl / g]

TPU-b2: Polyester diol (1) / 4,4′-diphenylmethane diisocyanate / 1,4-butanediol thermoplastic polyurethane [nitrogen atom content: 2.8% by weight, differential scanning calorimetry (DS)
Endothermic peak temperature of C) 202 ° C., crystallization enthalpy (ΔH) 4.0 J / g, logarithmic viscosity 0.57 dl / g]

TPU-b3: Polyester diol comprising 1,4-butanediol and adipic acid (number average molecular weight 1000) / 4,4′-diphenylmethane diisocyanate / 1,4-butanediol-based thermoplastic polyurethane [nitrogen atom content 4.4% by weight, differential scanning calorimetry (DSC) endothermic peak temperature of 175 ° C., crystallization enthalpy (ΔH) 0 J / g, logarithmic viscosity 0.90 dl / g]

TPU-b4: Polyester diol (number average molecular weight 2000) / 4 comprising a mixture of 1,9-nonanediol and 2-methyl-1,8-octanediol (molar ratio 65:35) and adipic acid 4'-diphenylmethane diisocyanate / 1,4-butanediol-based thermoplastic polyurethane [nitrogen atom content 4.3% by weight,
Endothermic peak temperature 228 of differential scanning calorimetry (DSC)
° C, crystallization enthalpy (ΔH) 20.5 J / g, logarithmic viscosity 0.70 dl / g]

POE-A : ethylene-1-octene copolymer [“ENGAG” manufactured by Dupont Dow Elastomer Co., Ltd.]
EEG8100 "; the molar ratio of ethylene units / 1-octene units is 92.7 / 7.3, and the melt index (1
90 ° C., 2.16 kg load) 1.0 g / 10 min, Shore A hardness 75, Mooney viscosity 35.6 ML
_{1 + 4} (100 ° C), density 0.870g / cm ³ ]

POE-B : ethylene-1-octene copolymer [“ENGAG” manufactured by Dupont Dow Elastomer Co., Ltd.]
EEG8200 "; the molar ratio of ethylene units / 1-octene units is 92.2 / 7.8, and the melt index (1
90 ° C., 2.16 kg load) 4.2 g / 10 min, Shore A hardness 75, Mooney viscosity 12.1 ML _{1 + 4} (1
00 ° C.) and a density of 0.870 g / cm ³ ]

PO : polyethylene [melt index (190 ° C., 2.16 kg load) is 0.11 g / 10
Min, the density is 0.960 g / cm ³ ]

AM : ethylene bisstearic acid amide

Examples 1-4 Thermoplastic polyurethane (TPU) and ethylene-α-
A mixture obtained by blending an olefin copolymer (POE) at a ratio shown in Table 1 below was mixed with a single screw extruder (25 mmφ,
Cylinder temperature: 180-200 ° C, die temperature: 20
(0 ° C.) to produce a thermoplastic polyurethane composition. Table 1 below shows the results of the evaluation of the thermoplastic polyurethane composition by the above evaluation method.

Example 5 Thermoplastic polyurethane (TPU), ethylene-α-olefin copolymer (POE) and polyolefin (P
O) was used in the proportions shown in Table 1 below,
In the same manner as in Examples 1 to 4, a thermoplastic polyurethane composition was produced. Table 1 below shows the results of the evaluation of the thermoplastic polyurethane composition by the above evaluation method.

Example 6 Thermoplastic polyurethane (TPU), ethylene-α-olefin copolymer (POE) and bisamide compound (A
M) was used in the proportions shown in Table 1 below,
In the same manner as in Examples 1 to 4, a thermoplastic polyurethane composition was produced. Table 1 below shows the results of the evaluation of the thermoplastic polyurethane composition by the above evaluation method.

[0082]

[Table 1]

Comparative Examples 1 and 2 Thermoplastic polyurethane (TPU) and ethylene-α-
A thermoplastic polyurethane composition was produced in the same manner as in Examples 1 to 4, except that the olefin copolymer (POE) was used at a ratio shown in Table 2 below. Table 2 below shows the results of the evaluation of the thermoplastic polyurethane composition by the above evaluation method.

Comparative Example 3 Thermoplastic polyurethane (TPU) and ethylene-α-
A thermoplastic polyurethane composition was produced in the same manner as in Examples 1 to 4, except that the olefin copolymer (POE) was used at a ratio shown in Table 2 below. A film having a thickness of 30 μm was produced from this thermoplastic polyurethane composition. However, since the film had poor blocking resistance and was difficult to be rewound, a 100% modulus (M1
00), the residual strain and the adhesiveness could not be evaluated. The obtained evaluation results are shown in Table 2 below.

Comparative Examples 4, 5 Thermoplastic polyurethane (TPU) and ethylene-α-
A thermoplastic polyurethane composition was produced in the same manner as in Examples 1 to 4, except that the olefin copolymer (POE) was used at a ratio shown in Table 2 below. A film having a thickness of 30 μm was produced from this thermoplastic polyurethane composition. However, the resulting film was cracked, and a film whose blocking resistance, 100% modulus (M100), residual strain and adhesion could be evaluated could not be obtained. Was. The obtained evaluation results are shown in Table 2 below.

[0086]

[Table 2]

[0087]

According to the thermoplastic polyurethane composition of the present invention, the neck-in phenomenon that occurs when melt-extrusion molding is performed with a T-die type extruder or the like is remarkably improved, and the blocking resistance is also excellent. Furthermore, thickness unevenness and cracks generated when melt-molding with an inflation molding machine are remarkably improved. By using the thermoplastic polyurethane composition of the present invention, a molded article such as a film or a sheet having an appropriate strength, not only having a small residual strain after elongation, but also having excellent adhesion to various substrates, It can be manufactured with high productivity.

Claims (3)

[Claims] 1. A thermoplastic polyurethane composition comprising (i) a thermoplastic polyurethane (a), a thermoplastic polyurethane (b) and an ethylene-α-olefin copolymer (c); (ii) the thermoplastic polyurethane A polyurethane (a) having a number of hydroxyl groups per molecule of 2.01 to 2.10 and a number of high molecular weight polyol units having a number average molecular weight of 500 to 8,000,
A thermoplastic polyurethane comprising an organic diisocyanate unit and a chain extender unit and having a nitrogen atom content of 2.5% by weight or less; (iii) the thermoplastic polyurethane (b) has a number average molecular weight of 1,500 to 5; 2,000 polyester diol units, organic diisocyanate units and chain extender units, having a nitrogen atom content of at least 2.6% by weight, and an endothermic peak in the range of 200 to 220 ° C. by differential scanning calorimetry (DSC). A thermoplastic polyurethane having a enthalpy of crystallization (ΔH) of 2 to 15 J / g as determined from the endothermic peak; and (iv) the total weight of the thermoplastic polyurethane (a) and the thermoplastic polyurethane (b) 40 to 80% by weight of thermoplastic polyurethane (a) and 60 to 20% by weight of thermoplastic polyurethane (b) based on And that the thermoplastic polyurethane composition characterized ethylene -α- olefin copolymer (c) are contained in a proportion of 5 to 250 wt%. 2. A molded article comprising the thermoplastic polyurethane composition according to claim 1. 3. The molded article according to claim 2, which is a film or a sheet.