JPH11228810A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition capable of manufacturing formed products such as films and sheets having excellent quality in high productivity, and the formed products obtained from the composition. SOLUTION: This composition comprises (a) a thermoplastic polyurethane consisting of a polymer polyol unit having 2.01 to 2.10 of hydroxyl groups per molecule and a number overage molecular weight of 500 to 8000, an organic diisocyante unit and a chain extender unit, (b) an ethylene-α-olefin copolymer, (c) a block copolymer consisting of an aromatic vinyl polymer block and a conjugated diene polymer block and their hydrogenated products, and containing 30 to 90 wt.%. of the component (a), 70 to 10 wt.%. of the component (b), 1-30 wt.%. of the component (c) based on the sum of the components (a) and (b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a specific thermoplastic polyurethane, an ethylene-α-olefin copolymer, a block copolymer comprising an aromatic vinyl compound polymer block and a conjugated diene polymer block, and the block copolymer. The present invention relates to a thermoplastic resin composition comprising at least one hydrogenated copolymer, a film, a sheet, and other molded articles comprising the thermoplastic resin composition. The thermoplastic resin composition of the present invention is excellent in melt moldability, and in particular, a high-quality molded product such as a film or sheet can be produced by melt extrusion molding.

[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. This elastic film for disposable diapers is intended to prevent the disposable diaper from coming off the body with a moderate force when the disposable diaper is attached, and to be thin and can be stretched with a small force. Instead, the stress (recovery stress) that tries to return to the original shape after elongation is high,
It is required to have the property of being excellent in dimensional stability (small residual strain).

[0003] In order to satisfy such demands,
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.

[0004] In recent years, it has been proposed to blend an olefin or styrene elastomer for the purpose of improving the adhesive property and performance of the thermoplastic polyurethane while maintaining the properties of the thermoplastic polyurethane. For example, JP-A-8-
No. 143766 discloses polyester diol units,
A thermoplastic polymer composition in which an olefin elastomer and an aromatic vinyl compound-conjugated diene block copolymer are blended with a general thermoplastic polyurethane comprising an organic diisocyanate unit and a chain extender unit is described.

[0005]

However, according to the study of the present inventors, it is impossible to obtain a T-die type extruder or the like simply by blending an olefin or styrene elastomer with a general thermoplastic polyurethane. It has been found that the neck-in phenomenon that occurs when melt-extrusion of a molded article such as a film or a sheet by using the same is not sufficiently improved.

An object of the present invention is to improve a neck-in phenomenon that occurs when melt-extrusion molding is performed using a T-die extruder or the like,
It is an object of the present invention to provide a thermoplastic resin composition capable of producing high-quality molded articles such as films and sheets with high productivity. It is a further object of the present invention to provide a molded article such as a film or sheet made of the thermoplastic resin composition.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted various studies to achieve the above object, and as a result, have found that the number of hydroxyl groups per molecule is from 2.01 to 2.10. And a specific thermoplastic polyurethane comprising a chain extender unit, an ethylene-α-olefin copolymer, a block copolymer comprising an aromatic vinyl compound polymer block and a conjugated diene polymer block, and the block copolymer. By blending at least one of the combined hydrogenated products, the neck-in phenomenon at the time of melt-extrusion molding with a T-die type extruder or the like is sufficiently improved, and a molded article free from defective phenomena such as necking and cracking can be obtained. They have found that they can be manufactured with good productivity, and have completed the present invention based on these findings.

That is, the present invention relates to (i) a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b), and a block composed of an aromatic vinyl compound polymer block and a conjugated diene polymer block. A thermoplastic resin composition comprising a copolymer and at least one kind of a hydrogenated product of the block copolymer (c) (hereinafter may be referred to as “block copolymer (c)”);
(Ii) thermoplastic polyurethane (a) and ethylene-α
-30 to 90% by weight of thermoplastic polyurethane (a), 70 to 10% by weight of ethylene-α-olefin copolymer (b), and aromatic vinyl based on the total weight of olefin copolymer (b). A block copolymer composed of a compound polymer block and a conjugated diene polymer block and at least one kind (c) of a hydrogenated product of the block copolymer in a proportion of 1 to 30% by weight; and ( ii
i) 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 500 to 8,000, a high molecular weight polyol unit, an organic diisocyanate unit and a chain extension. It is a thermoplastic resin composition characterized by being a thermoplastic polyurethane comprising an agent unit. Further, the present invention is a molded article such as a film or a sheet made of the thermoplastic resin composition.

[0009]

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.

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 to, for example, a direct esterification reaction or a transesterification reaction between the polyol and an ester-forming derivative such as a polycarboxylic acid or an ester or an anhydride thereof 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. 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,
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. It is preferable to use a small amount of trimethylolpropane from the viewpoint that a thermoplastic resin 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 can be used. 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 (methyltetrafluoroethylene) 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, diaryl carbonate and the like 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 is 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 hydroxyl group number of 2.01 per molecule.
２．１2.10.
7, and more preferably 2.01 to 2.05. When the number of hydroxyl groups per molecule of the polymer polyol is less than 2.01, when a molded article such as a film or a sheet is melt-extruded from a thermoplastic resin composition obtained by a T-die extruder or the like, a neck-in phenomenon occurs. As a result, the width of a molded product such as an extruded film or sheet becomes considerably smaller than the effective width of the T-die. Furthermore, since unevenness in thickness occurs at both ends of a molded product such as a film or a sheet, the productivity of a product obtained by trimming the thickness unevenness portion is low. Further, when a molded product such as a film or a sheet extruded from a T-die is taken up at a high speed, defective phenomena such as necking and cracking are likely to occur.
On the other hand, when a polymer polyol having more than 2.10 hydroxyl groups per molecule is used, a film having a small thickness, a good surface state, and excellent stretchability is obtained from the obtained thermoplastic resin composition. It will be difficult to obtain.

Examples of the high molecular polyol constituting the thermoplastic polyurethane (a) include, among the above-mentioned raw material components of the high molecular polyol, 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 in this range, a thermoplastic resin composition having more excellent mechanical performance and melt moldability can be obtained. The number average molecular weight of the high molecular polyol referred to in the present specification is J
It is a number average molecular weight calculated based on a hydroxyl value measured according to IS K-1577.

The organic diisocyanate used for producing the thermoplastic polyurethane (a) is not particularly limited.
Any of the organic diisocyanates conventionally used in the production of ordinary thermoplastic polyurethanes may be used. For example, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, 1,5- Naphthylene diisocyanate, 3,3'-dichloro-4,
Aromatic diisocyanates such as 4'-diphenylmethane diisocyanate and toluylene diisocyanate; aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and hydrogenated xylylene diisocyanate; it can. These organic diisocyanates may be used alone or in combination of two or more. Among these,
It is preferred to use 4,4'-diphenylmethane diisocyanate.

The chain extender used in the production of the thermoplastic polyurethane (a) is not particularly limited, and any of the chain extenders conventionally used in the production of ordinary thermoplastic polyurethanes may be used. Molecular weight 3 having at least two active hydrogen atoms capable of reacting with isocyanate groups in the molecule
It is preferable to use a low-molecular compound of not more than 00. For example, ethylene glycol, propylene glycol, 1,
4-butanediol, 1,6-hexanediol, 1,
4-bis (β-hydroxyethoxy) benzene, 1,4
Diols such as cyclohexanediol, bis (β-hydroxyethyl) terephthalate and xylylene glycol; hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine and derivatives thereof, phenylenediamine, tolylenediamine, xylenediamine, Diamines such as adipic dihydrazide and isophthalic dihydrazide; and 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 these, it is preferable to use an aliphatic diol having 2 to 10 carbon atoms, and it is more preferable to use 1,4-butanediol.

In producing the thermoplastic polyurethane (a) by reacting the above-mentioned polymer polyol, organic diisocyanate and chain extender, the mixing ratio of each component depends on the hardness to be imparted to the target thermoplastic polyurethane. It is appropriately determined in consideration of the isocyanate group contained in the organic diisocyanate is 0.9 to 1 mol per active hydrogen atom contained in the polymer polyol and the chain extender.
It is preferable to use each component at a ratio of 1.2 mol.

The method for producing the thermoplastic polyurethane (a) is not particularly limited, and the prepolymer method and the urethanization reaction technique using the above-mentioned polymer polyol, organic diisocyanate and chain extender are used. It may be manufactured by any one-shot method. Among them, it is preferable to carry out melt polymerization substantially in the absence of a solvent, and particularly preferable to use continuous melt polymerization using a multi-screw extruder.

JIS A for thermoplastic polyurethane (a)
The hardness is preferably from 55 to 85, and is preferably from 60 to 80.
Is more preferable. The thermoplastic polyurethane (a) having a JIS A hardness in this range has more excellent compatibility with the ethylene-α-olefin copolymer (b) and the block copolymer (c). In the case where is used, sufficient flexibility and good mechanical properties are imparted to a molded article obtained from the thermoplastic resin composition. In addition, the thermoplastic polyurethane (a) referred to in this specification
Is a value measured according to JIS K-7311.

The logarithmic viscosity of the thermoplastic polyurethane (a) is determined by dissolving the thermoplastic polyurethane (a) in an N, N-dimethylformamide solution at 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. It is preferable to use a thermoplastic polyurethane having the above-mentioned logarithmic viscosity, since a thermoplastic resin composition that gives a molded article with less residual strain can be obtained.

Ethylene-α-olefin copolymer (b)
Is composed of an ethylene unit and an α-olefin unit. Examples of the α-olefin unit constituting the ethylene-α-olefin copolymer (b) 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 (b)
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. Content of ethylene unit is 5
When the amount is less than 5 mol%, the softening temperature of the ethylene-α-olefin copolymer becomes low, and it becomes difficult to uniformly mix with the thermoplastic polyurethane (a) or the block copolymer (c). When the ethylene-α-olefin copolymer is used, the film obtained from the thermoplastic resin composition tends to stick easily. On the other hand, when an ethylene-α-olefin copolymer having an ethylene unit content of more than 99 mol% is used, it tends to be difficult to obtain a film having a small thickness and excellent stretchability.

Ethylene-α-olefin copolymer (b)
The melt index measured at 190 ° C. under a load of 2.16 kg is preferably in the range of 0.1 to 12 g / 10 min, more preferably in the range of 0.2 to 7 g / 10 min. More preferably, it is in the range of 0.4 to 5 g / 10 minutes. When the ethylene-α-olefin copolymer (b) having the above melt index is used, it is excellent in melt moldability when producing a film or a sheet, can achieve a thin film, has anti-blocking properties, flexibility,
A material having more excellent recovery performance such as recovery stress and residual strain after elongation can be obtained. In addition, ethylene-α referred to in this specification
-The melt index of the olefin copolymer (b) is
It is a value measured in accordance with ASTM D-1238.

Ethylene-α-olefin copolymer (b)
Is preferably in the range of 30 to 90, more preferably in the range of 40 to 85. When the ethylene-α-olefin copolymer (b) having the above Shore A hardness is used, a thermoplastic resin composition and a molded article obtained therefrom are more excellent in elastic recovery and mechanical performance. . The Shore A hardness of the ethylene-α-olefin copolymer (b) referred to in the present specification is a value measured according to ASTM D-2240.

Ethylene-α-olefin copolymer (b)
Is preferably a Mooney viscosity measured at 100 ° C. using an L-shaped rotor is in the range of _{5~60ML 1 + 4 (100 ℃)} , within the scope of 10~38ML ₁ + 4 (100 ℃) More preferably, there is. When the ethylene-α-olefin copolymer (b) having the above Mooney viscosity is used, one having more excellent blocking resistance, flexibility, and recovery performance such as recovery stress after elongation and residual strain can be obtained.
The Mooney viscosity of the ethylene-α-olefin copolymer (b) referred to in the present specification is a value measured according to ASTM D-1646.

Ethylene-α-olefin copolymer (b)
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.

Aromatic vinyl compound in the block copolymer (c) Examples of the aromatic vinyl compound constituting the polymer block include styrene, α-methylstyrene,
3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, 1-vinylnaphthalene, and the like. Species or two or more can be used. Of these, styrene and α-methylstyrene are preferably used.

The conjugated diene constituting the conjugated diene polymer block in the block copolymer (c) includes, for example, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,2 Examples thereof include 3-butadiene, 2-neopentyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene, and one or more of these can be used. Among these, 1,3-butadiene and 2-methyl-1,3-butadiene are preferably used.

The bonding form between the aromatic vinyl compound polymer block and the conjugated diene polymer block in the block copolymer (c) is not particularly limited, and may be linear, branched, radial, or two or more of them. Any combination of bonding forms may be used, and a linear bonding form is preferable. As examples of the block copolymer (c), when an aromatic vinyl compound polymer block is represented by X and a conjugated diene polymer block is represented by Y, (XY) nX,
(XY) m, Y- (XY) p [n, m and p each represent an integer of 1 or more. ] And the like. Among them, X-
It is preferable to use a diblock copolymer represented by Y and a triblock copolymer represented by XYX.

As the block copolymer (c), those in which part or all of the unsaturated double bonds in the conjugated diene polymer block are hydrogenated can also be used. Such a hydrogenated block copolymer (c)
When a is used, a thermoplastic polymer composition having better heat resistance, light resistance and the like can be obtained.

In the block copolymer (c), the content of the structural unit derived from the aromatic vinyl compound is preferably from 5 to 75% by weight based on all the structural units, and is preferably from 10 to 65% by weight.
More preferably, it is% by weight. When a block copolymer (c) containing a structural unit derived from an aromatic vinyl compound within the above range is used, excellent melt moldability when producing a film or sheet, thinning can be achieved, and blocking resistance is achieved. It is possible to obtain a resin having better recovery properties such as flexibility, flexibility, recovery stress after elongation and residual strain.

230 ° C. of the block copolymer (c);
The melt index measured under a load of 16 kg is 10
It is preferably at most 0 g / 10 min, more preferably at most 80 g / 10 min. When the block copolymer (c) having the above melt index is used, it is excellent in melt moldability when producing a film or a sheet, can be formed into a thin film, has blocking resistance, flexibility, recovery stress after elongation, and the like. A material having better recovery performance such as residual strain can be obtained. In addition, the melt index of the block copolymer (c) referred to in the present specification is a value measured according to ASTM D-1238.

The JIS A hardness of the block copolymer (c) is preferably from 30 to 98. The block copolymer (c) having a JIS A hardness within this range has better compatibility with the thermoplastic polyurethane (a) and the ethylene-α-olefin copolymer (b). When a polymer is used, a molded article obtained from the thermoplastic resin composition is given sufficient flexibility and good mechanical performance. The JIS A hardness of the block copolymer (c) referred to in the present specification is a value measured according to JIS K-6301.

The thermoplastic resin composition of the present invention contains 30 to 90 parts of the thermoplastic polyurethane (a) based on the total weight of the thermoplastic polyurethane (a) and the ethylene-α-olefin copolymer (b). % By weight, ethylene-α-
It is necessary to contain the olefin copolymer (b) at a ratio of 70 to 10% by weight, and the thermoplastic polyurethane (a) is 45 to 90% by weight, and the ethylene-α-olefin copolymer (b) is used. Is preferably contained at a ratio of 55 to 10% by weight. When the content of the thermoplastic polyurethane (a) is less than 30% by weight, the mechanical performance, recovery stress, and recovery performance such as residual strain of a film obtained from the thermoplastic resin composition are impaired. 9 content
If it exceeds 0% by weight, the blocking resistance is poor.

The content of the block copolymer (c) is in the range of 1 to 30% by weight based on the total weight of the thermoplastic polyurethane (a) and the ethylene-α-olefin copolymer (b). , Preferably in the range of 2 to 20% by weight. When the content of the block copolymer (c) is less than 1% by weight, the blocking resistance is poor. Even when the content of the block copolymer (c) exceeds 30% by weight, the blocking resistance is inferior, and the mechanical performance, recovery stress, and residual strain of a film obtained from the thermoplastic resin composition are also poor. Be impaired.

The thermoplastic resin composition of the present invention may contain a polyolefin resin such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, polypropylene and polybutylene, and a paraffinic oil for the purpose of further improving blocking resistance. Can be blended.

Further, the thermoplastic resin composition of the present invention comprises:
Various additives such as a reinforcing agent, a coloring agent, a flame retardant, an ultraviolet absorber, an antioxidant, a hydrolysis resistance improving agent, a fungicide, an antibacterial agent, and a stabilizer, as long as the effects of the present invention are not impaired; Various components such as fibers and polyester fibers; inorganic materials such as talc and silica; and optional components such as various coupling agents can be added as necessary.

The thermoplastic resin composition of the present invention comprises the above-mentioned thermoplastic polyurethane (a), ethylene-α-olefin copolymer (b), block copolymer (c) and, if necessary, other components. And by mixing in a desired manner. For example, a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b), and a block copolymer (c) are prepared by using a vertical or horizontal mixer as generally used for mixing resin materials. After pre-mixing other components at a predetermined ratio as required, melt-kneading is performed batchwise or continuously by heating using a single-screw or twin-screw extruder, mixing roll, Banbury mixer, etc. Can be manufactured. As another method, for example, an ethylene-α-olefin copolymer (b), a block copolymer (c), and other components as necessary, may be used in the late stage of polymerization when producing the thermoplastic polyurethane (a). May be blended.

The thermoplastic resin composition of the present invention can be melt-molded, and can smoothly produce various molded articles by any molding method such as extrusion molding, injection molding, blow molding, calender molding, and casting. be able to. In particular, since the thermoplastic resin composition of the present invention is excellent in melt extrusion moldability, for example, in molding of a film or a sheet by a T-die type extruder, a film extruded from the effective width of the T-die. The neck-in phenomenon, in which the width of molded articles such as sheets and sheets, is considerably reduced, has been significantly improved, and the range of thickness unevenness at both ends of molded articles such as films and sheets caused by the neck-in phenomenon is narrowed. The productivity of the 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, resulting in necking or cracking that causes constriction. As a result, a high quality product can be obtained with high productivity. Furthermore, molded articles such as films and sheets obtained by using the thermoplastic resin composition of the present invention are excellent in stretchability at low stress, recovery performance such as recovery stress or residual strain after elongation, tensile fracture. Excellent mechanical performance represented by strength and tensile elongation at break, etc.
Moreover, it has a smooth surface and good surface condition.
In particular, it excels in elasticity at low stress and recovery performance such as recovery stress after elongation and residual strain.Employing these characteristics, it is used for disposable diapers, sanitary napkins, sealing, and dustproofing. It is particularly preferred to use it for stretch film applications. 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 resin composition of the present invention has excellent adhesiveness with a fibrous base material made of a nonwoven fabric or another fiber cloth, or a base material made of another polymer film or sheet. Therefore, it is suitable for manufacturing a laminate. For example, the thermoplastic resin composition of the present invention can be melt-extruded on a fibrous base material or another base material into a film or a sheet to produce a laminate.

[0046]

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, melt moldability, film production state, surface state, blocking resistance, 100% modulus (M100) and residual strain were measured or evaluated by the following methods.

[Melt Formability] While discharging the film extruded from the T-die extruder, the film width 10 cm below the T-die exit was measured, and the following formula (1) was obtained.
The neck-in rate (%) was determined in accordance with the above and was used as an index of the melt moldability. The smaller this value is, the more the neck-in phenomenon is improved, indicating that the melt-moldability is excellent. Neck-in rate (%) = (W ₂ −W ₁ ) / W ₂ × 100 (1) (where W ₁ is the film width 10 cm below the T-die exit, and W ₂ is the effective width of the T-die Is shown.)

[Film Production State, Surface State] The film cooled by being extruded from a T-die type extruder onto a cooling roll at 30 ° C. is taken up at a winding speed of about 2.5 m / min without using release paper. Rolled up. 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 2.5 m / min without using release paper. . The wound film is allowed to stand at room temperature for 24 hours.
After being left for a while, it 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 50 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 smaller the value of the 100% modulus (M100), the better the extensibility at low stress. In addition, the smaller the value of the residual strain, the better the recovery performance that returns to the original state after elongation.

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

TPU-A : Polyester polyol produced by reacting 3-methyl-1,5-pentanediol with adipic acid, having 2.00 hydroxyl groups per molecule and having a number average molecular weight of 3500 (Hereinafter, referred to as “polyester polyol (1)”), and 3-methyl-1,5-pentanediol, trimethylolpropane, and adipic acid, which have a hydroxyl group number of 3 per molecule. And a mixture of polyester polyols having a number average molecular weight of 2,000 (hereinafter referred to as “polyester polyol (2)”) in which the molar ratio of polyester polyol (1) / polyester polyol (2) is 98/2. The number of hydroxyl groups per molecule is 2.02], 4,4'-diphenylmethane diisocyanate and Thermoplastic polyurethane [JIS A hardness obtained is reacted with 4-butanediol 7
5, logarithmic viscosity is 1.02 dl / g]

TPU-B : a mixture of polyester polyol (1) and polyester polyol (2) [polyester polyol (1) / polyester polyol (2) molar ratio: 95/5, number of hydroxyl groups per molecule: 2.05 Is reacted with 4,4'-diphenylmethane diisocyanate and 1,4-butanediol to obtain a thermoplastic polyurethane [JIS A hardness of 6
5, logarithmic viscosity is 1.25 dl / g]

TPU-C : 2,7-dimethyl-1,8-
A mixture of octanediol and 2,8-dimethyl-1,9-nonanediol (molar ratio: 35:65) and adipic acid produced, the number of hydroxyl groups per molecule was 2.00, and the number average A mixture of a polyester polyol having a molecular weight of 2,000 (hereinafter referred to as “polyester polyol (3)”) and a polyester polyol (2) [polyester polyol (3) / polyester polyol (2) has a molar ratio of 97/3] A thermoplastic polyurethane obtained by reacting 2.03] of hydroxyl groups per molecule with 4,4'-diphenylmethane diisocyanate and 1,4-butanediol [JI
SA hardness is 70, logarithmic viscosity is 1.15 dl / g]

TPU-D : Polyester polyol (1) having 2.00 hydroxyl groups per molecule,
4'-diphenylmethane diisocyanate and 1,4
-Thermoplastic polyurethane obtained by reaction with butanediol [JIS A hardness: 75, logarithmic viscosity: 1.00 d
l / g]

TPU-E: a mixture of polyester polyol (1) and polyester polyol (2) [polyester polyol (1) / polyester polyol (2) has a molar ratio of 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 [JIS A hardness: 75;
DMF solvent insoluble]

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 ℃)]

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)]

TPS-A : hydrogenated product of a triblock copolymer consisting of a polystyrene block-polyisoprene block-polystyrene block [styrene content is 30
% By weight, the content of 1,2-bonds and 3,4-bonds in the polyisoprene block is 7%, the hydrogenation ratio in the polyisoprene block is 95%, and the melt index (230 ° C., 2.16 kg load) is 70 g. / 10 minutes, J
IS A hardness is 80]

TPS-B : hydrogenated triblock copolymer composed of polystyrene block-polyisoprene block-polystyrene block [styrene content is 20
% By weight, the content of 1,2-bonds and 3,4-bonds in the polyisoprene block is 55%, the hydrogenation rate in the polyisoprene block is 92%, and the melt index (230 ° C., 2.16 kg load) is 6 g. / 10 minutes, JI
SA hardness is 52]

TPS-C : a mixture (weight ratio) of a hydrogenated product of a diblock copolymer composed of a polystyrene block and a polyisoprene block and a hydrogenated product of a triblock copolymer composed of a polystyrene block—a polyisoprene block—a polystyrene block 20:80) [styrene content: 13% by weight, content of 1,2-bond and 3,4-bond in polyisoprene block: 5%, hydrogenation rate in polyisoprene block: 98%, melt index (230 ° C., 2.16 kg load) is 0.
5 g / 10 min, JIS A hardness is 52]

TPS-D : hydrogenated triblock copolymer consisting of polystyrene block-polyisoprene block-polystyrene block [styrene content is 30
% By weight, content of 1,2- and 3,4-bonds in the polyisoprene block is 5%, hydrogenation rate in the polyisoprene block is 98%, melt index (230 ° C, 2.16 kg load) is flowing Measurement is not possible

TPS-E : triblock copolymer composed of polystyrene block-polyisoprene block-polystyrene block [styrene content: 15% by weight, content of 1,2-bond and 3,4-bond in polyisoprene block Is 5%, melt index (190 ° C,
2.16 kg load) is 2 g / 10 min, JIS A hardness is 37]

PE : polyethylene [melt index (190 ° C., 2.16 kg load) is 0.04 g / 10
Min, density 0.956 g / cm ³ ]

PP : polypropylene [melt index (230 ° C., 2.16 kg load) is 240 g / 10
Minutes)

Oil : paraffinic oil [containing 70% by weight of paraffin and 30% by weight of naphthene, and having a kinematic viscosity of 4 × 10 ^-4 m ^-2 / sec (40 ° C)]

Examples 1 to 6 Thermoplastic polyurethane (TPU), ethylene-α-olefin copolymer (POE), block copolymer (TP
A mixture of S) and other components (PE, PP, oil) compounded in the proportions shown in Table 1 below was prepared using a single-screw extruder (25 mmφ, cylinder temperature: 180 to 200 ° C,
The thermoplastic resin composition was manufactured by melt-kneading at a die temperature of 200 ° C.). Table 1 below shows the results of the evaluation of the thermoplastic resin composition by the above evaluation method.

[0068]

[Table 1]

Comparative Examples 1 and 2 Thermoplastic polyurethane (TPU), ethylene-α-olefin copolymer (POE) and block copolymer (T
PS) was used in the same manner as in Examples 1 to 6, except that the thermoplastic resin composition was used in the proportions shown in Table 2 below. Table 2 below shows the results of the evaluation of the thermoplastic resin composition by the above evaluation method.

Comparative Examples 3 and 4 Thermoplastic polyurethane (TPU), ethylene-α-olefin copolymer (POE) and block copolymer (T
PS) was used in the same manner as in Examples 1 to 6, except that the thermoplastic resin composition was used in the proportions shown in Table 2 below. A thickness of 50 μm is obtained from the thermoplastic resin composition.
An attempt was made to produce a film having a film thickness of m, but the film cracked during the production, and no film was obtained whose blocking resistance, 100% modulus (M100) and residual strain could be evaluated. The obtained evaluation results are shown in Table 2 below.

[0071]

[Table 2]

[0072]

As described above, the thermoplastic resin composition of the present invention has a remarkably improved neck-in phenomenon which is generated when a melt-extrusion molding is performed by a T-die type extruder or the like, and is excellent in blocking resistance. By using the thermoplastic resin composition of the present invention, molded products such as high quality films and sheets can be manufactured with high productivity.

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁶ identifications FI C08L 23:04 53:02)

Claims (3)

[Claims] (I) a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b), a block copolymer comprising an aromatic vinyl compound polymer block and a conjugated diene polymer block, and A thermoplastic resin composition comprising at least one type (c) of a hydrogenated product of the block copolymer; (ii) a thermoplastic polyurethane (a) and ethylene-α
-30 to 90% by weight of thermoplastic polyurethane (a), 70 to 10% by weight of ethylene-α-olefin copolymer (b), and aromatic vinyl based on the total weight of olefin copolymer (b). A block copolymer composed of a compound polymer block and a conjugated diene polymer block and at least one type (c) of a hydrogenated product of the block copolymer in a proportion of 1 to 30% by weight; iii) 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 500 to 8,000, a high molecular weight polyol unit, an organic diisocyanate unit and a chain extension. A thermoplastic resin composition characterized in that it is a thermoplastic polyurethane composed of an agent unit. 2. A molded article comprising the thermoplastic resin composition according to claim 1. 3. The molded article according to claim 2, which is a film or a sheet.