JPH11152405A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a thermoplastic resin composition capable of producing a molded product such as a film or a sheet having excellent elongation at a low stress, high recovery stress after elongation and a low residual strain after elongation and a molded product comprising the composition. SOLUTION: The thermoplastic resin composition comprises (a) a thermoplastic polyurethane comprising a polymer polyol unit having 2.01-2.10 hydroxyl groups per molecule and 500-8,000 number-average molecular weight, an organic diisocyanate unit and a chain extender unit, (b) an ethylene-α-olefin copolymer having a molar ratio of ethylene unit/α-olefin unit of 75/25-95/5 and (c) an polyolefin-based resin having 0.01-0.3 g/10 minutes melt index. In this case, the composition includes 30-90 wt.% of the component (a), 70-10 wt.% of the component (b) and 5-17 wt.% of the component (c) based on the total of the components (a) and (b). The molded product is obtained from the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoplastic resin composition comprising a specific thermoplastic polyurethane, an ethylene-α-olefin copolymer and a polyolefin resin, and a film, a sheet and the like comprising the thermoplastic resin composition. Related to molded products. The thermoplastic resin composition of the present invention is excellent in melt moldability, blocking resistance and the like. Further, molded articles such as films and sheets obtained from the thermoplastic resin composition have excellent extensibility at low stress, high recovery stress after elongation, and small residual strain after elongation. It is useful as various elastic materials.

[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 yield 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, it has been proposed to blend a thermoplastic polyurethane with a polyolefin-based resin for the purpose of improving the adhesive property and performance of the thermoplastic polyurethane while maintaining the properties of the thermoplastic polyurethane. For example, Japanese Unexamined Patent Publication
JP-156152 describes a thermoplastic polyurethane resin composition in which a polyethylene-based resin and an ethylene-propylene copolymer-based rubber are blended with a thermoplastic polyurethane.

[0005]

However, according to the study of the present inventors, simply blending a polyolefin-based resin with a general thermoplastic polyurethane and using a T-die type extruder or the like to form a film or the like. It has been found that the neck-in phenomenon that occurs when a molded article such as a sheet is melt-molded is not sufficiently improved.

An object of the present invention is to provide a thermoplastic resin composition in which the neck-in phenomenon which occurs during melt extrusion molding with a T-die extruder or the like is remarkably improved, and which has excellent blocking resistance. A thermoplastic resin composition that can produce molded products such as films and sheets with excellent stretchability, high recovery stress after stretching, and small residual strain after stretching with high yield and high productivity. To provide. It is still another object of the present invention to provide a molded article such as a film or sheet made of the thermoplastic resin composition.

[0007]

The inventors of the present invention have conducted various studies to achieve the above objects, and as a result, have found that the number of hydroxyl groups per molecule is from 2.01 to 2.10. When melt-extrusion molding with a T-die type extruder or the like is the first time that a specific amount of a specific ethylene-α-olefin copolymer and a polyolefin resin is blended with a specific thermoplastic polyurethane composed of The neck-in phenomenon that occurs is remarkably improved, and the blocking resistance is excellent, and it has been found that molded articles such as films and sheets having very suitable mechanical properties as elastic materials can be obtained. Based on this, the present invention has been completed.

That is, the present invention provides a thermoplastic resin composition comprising (i) a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b) and a polyolefin resin (c); A) thermoplastic polyurethane (a) and ethylene-α
30 to 90% by weight of the thermoplastic polyurethane (a) and 70 to 10% by weight of the ethylene-α-olefin copolymer (b), based on the total weight of the olefin copolymer (b).
And 5 to 17% by weight of a polyolefin resin (c); and (iii) the thermoplastic polyurethane (a) has a number of hydroxyl groups per molecule of 2.01 to 2.10. And a thermoplastic polyurethane comprising a polymer polyol unit having a number average molecular weight of 500 to 8,000, an organic diisocyanate unit and a chain extender unit; (iv) the ethylene-α-olefin copolymer (b).
Has a molar ratio of ethylene units / α-olefin units of 75
(V) the polyolefin-based resin (c) has a melt index (190 ° C., 2.16 kg load) of from 0.01 to 25/95 to 95/5;
A thermoplastic resin composition characterized by being a polyolefin-based resin having a flow rate of 0.3 g / 10 minutes. 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, 1,
3-butylene glycol, 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
Aliphatic diols having 2 to 15 carbon atoms, such as -nonanediol, 2,8-dimethyl-1,9-nonanediol, 1,10-decanediol, 2,2-diethyl-1,3-propanediol; Alicyclic diols such as 4-cyclohexanediol, cyclohexanedimethanol, cyclooctanedimethanol and dimethylcyclooctanedimethanol; per molecule of aromatic dihydric alcohol such as 1,4-bis (β-hydroxyethoxy) benzene Diols having two hydroxyl groups, 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. Among them, 2-methyl-1,4-butanediol, 3
-Methyl-1,5-pentanediol, 2-methyl-
1,8-octanediol, 2,7-dimethyl-1,8
It is preferable to use an aliphatic diol having 5 to 12 carbon atoms having a methyl group as a side chain, such as -octanediol, 2-methyl-1,9-nonanediol, and 2,8-dimethyl-1,9-nonanediol. Further, these aliphatic diols are more preferably used in a proportion of 30 mol% or more, more preferably 50 mol% or more, based on the total amount of the polyol. 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, for example, ε
-Caprolactone, β-methyl-δ-valerolactone and the like.

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 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. 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. Further, since uneven thickness occurs at both ends of a molded product such as a film or a sheet, the yield of a product obtained by trimming the uneven thickness 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, and it is still more preferable that it is 60-75. 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 polyolefin resin (c). When used, a molded article obtained from the thermoplastic resin composition is given sufficient flexibility and good mechanical properties. In addition,
JIS of thermoplastic polyurethane (a) referred to in this specification
The A hardness 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 ethylene units and α-olefin units,
And the molar ratio of ethylene units / α-olefin units is 75
/ 25 to 95/5, and 85/15 to 95 /
It is preferably within the range of 5. When the content of the ethylene unit is less than 75 mol%, the softening temperature of the ethylene-α-olefin copolymer becomes low, and the ethylene-α-olefin copolymer can be uniformly mixed with the thermoplastic polyurethane (a) or the polyolefin resin (c). Because of the difficulty, the film obtained from the thermoplastic resin composition obtained by blending the film tends to stick. On the other hand, when an ethylene-α-olefin copolymer having an ethylene unit content exceeding 95 mol% is used,
It is difficult to obtain a film having a small thickness and excellent elasticity.

Ethylene-α-olefin copolymer (b)
As the α-olefin unit constituting
Butene, 4-methyl-1-pentene, 1-hexene, 1
And units derived from octene, 1-decene, 1-octadecene and the like. These α-olefin units may be contained alone or in combination of two or more. Among these, a unit derived from an α-olefin having 4 or more carbon atoms is preferable, and a carbon number of 7 to 1 is preferable from the viewpoint of recovery performance such as recovery stress after elongation and residual strain.
Units derived from α-olefins of 2 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)
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. , 0.3 to 5.5 g / 10 min. 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, a thin film can be achieved, blocking resistance, flexibility, and after elongation. Which has more excellent recovery performance such as recovery stress and residual strain. The melt index of the ethylene-α-olefin copolymer referred to in the present specification is A
It is a value measured according to STM 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 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.
In addition, the Mooney viscosity referred to in this specification is ASTM D-
It is a value measured according to 1646.

Ethylene-α-olefin copolymer (b)
There is no particular limitation on the production method, and the above-mentioned monomers can be prepared, for example, by a known method such as a solution polymerization method, a bulk polymerization method, or a gas-phase polymer, usually at a temperature of 0 to 250 ° C. and an ordinary pressure of 1000 to 1000 ° C. 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.

Examples of the polyolefin resin (c) 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, the density of the polyolefin resin is 0.93 to 0.1.
High density polyethylene in the range of 97 g / cm ³ is particularly preferred. In addition, the density of the polyolefin-based resin referred to in the present specification is a value measured in accordance with ASTM D-1505.

The polyolefin resin (c) is 190
The melt index measured at 2.degree. C. under a load of 2.16 kg is in the range of 0.01 to 0.3 g / 10 minutes, and more preferably in the range of 0.02 to 0.2 g / 10 minutes.
Melt index of polyolefin resin is 0.01
In the case of less than g / 10 minutes, it becomes difficult to uniformly mix with the thermoplastic polyurethane (a) and the ethylene-α-olefin copolymer (b), and the thermoplastic resin composition obtained by blending the same is used. This causes cracks to occur in the film obtained from the above. On the other hand, when the melt index of the polyolefin resin exceeds 0.3 g / 10 minutes,
The film obtained from the thermoplastic resin composition containing the polyolefin resin has poor blocking resistance.

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 polyolefin resin (c) is
It is in the range of 5 to 17% by weight, preferably 5 to 12% by weight, based on the total weight of the thermoplastic polyurethane (a) and the ethylene-α-olefin copolymer (b). When the content of the polyolefin-based resin (c) is less than 5% by weight, the blocking resistance is inferior. On the other hand, when the content exceeds 17% by weight, the film-forming stability is impaired. In addition, recovery performance such as recovery stress and residual strain after elongation of the obtained film is impaired.

The thermoplastic resin composition of the present invention may further contain a reinforcing agent, a coloring agent,
Various additives such as flame retardant, ultraviolet absorber, antioxidant, hydrolysis resistance improver, fungicide, stabilizer, etc .; glass fiber,
Various components such as polyester fibers; inorganic materials such as talc and silica; and optional components such as various coupling agents can be blended as required.

The thermoplastic resin composition of the present invention comprises the thermoplastic polyurethane (a), the ethylene-α-olefin copolymer (b), the polyolefin resin (c) and other components as required. It can be produced by mixing in a desired manner. For example, a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b), and a polyolefin-based resin (c) are mixed with a vertical or horizontal mixer as generally used for mixing resin materials. Is premixed at a predetermined ratio, and then melt-kneaded in a batch or continuous manner with heating using a single-screw or twin-screw extruder, mixing roll, Banbury mixer, or the like. As another method, an ethylene-α-olefin copolymer (b) or a polyolefin-based resin (c) may be blended at a later stage of polymerization when producing the thermoplastic polyurethane (a).

The thermoplastic resin composition of the present invention can be melt-molded and heat-processed, and various molded articles can be smoothly molded by any molding method such as extrusion molding, injection molding, blow molding, calender molding and casting. Can be manufactured. 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 yield of the product obtained by trimming the uneven thickness 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 have recovery performance such as recovery stress and residual strain after elongation, and mechanical performance such as tensile breaking strength and tensile breaking elongation. And has a smooth surface and good surface condition. In particular, since it has excellent recovery performance such as recovery stress and residual strain after elongation, taking advantage of these characteristics, it is used for stretch films used for disposable diapers, sanitary napkins, seals, dust proofing, etc. Is particularly preferred. 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. Further, 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 also 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.

[0040]

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), 50% recovery stress and residual strain were measured or evaluated by the following methods.

[Melt 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 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 and surface state] A film extruded from a T-die extruder onto a cooling roll at 30 ° C. and cooled 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 was somewhat defective, such as cracks, but could be wound up. ×: A defective phenomenon such as cracking occurred in the film, and winding was impossible. 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 from a T-die type extruder onto a cooling roll at 30 ° C. and cooled was wound up 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. ：: Smooth rewinding is possible. Δ: A considerable tensile force was required, but rewinding was possible. ×: Adhesion between the films was remarkable, and rewinding was impossible.

[100% modulus (M100), 50
% Recovery stress, residual strain] From a 50 μm thick film formed using a T-die extruder, a test piece (20 cm
× 5 cm). The test piece was stretched 100% at room temperature at a tensile speed of 300 mm / min by using an autograph measuring device IS-500D (manufactured by Shimadzu Corporation).
The 0% modulus (M100) was measured. Then 300m
After returning to the position before elongation at the speed of m / min (first cycle), and then extending 100% at the same speed, the hysteresis curve was measured for two cycles by returning to the position before elongation. The stress at the time of returning to 50% elongation at the second cycle (50% recovery stress) and the residual strain at the time of returning to the position before elongation were determined. 100% modulus (M10
The smaller the value of 0), the better the extensibility at low stress. The greater the value of the 50% recovery stress, the greater the force to shrink from the stretched state. In addition, the smaller the value of the residual strain, the better the recovery performance that returns to the original state after elongation.

Abbreviations for 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 a hydroxyl number per molecule of 2.00 and a number average molecular weight of 3,500 (Hereinafter, referred to as “polyester polyol (1)”), and 3-methyl-1,5-pentanediol, trimellilolpropane, and adipic acid produced by reacting with 3 hydroxyl groups 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, the logarithmic viscosity is 1.10 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 1.13 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 and logarithmic viscosity is 1.10 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: 1.02 d
1 / 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 : an 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} (100 ℃)]

PO-A : polyethylene [“HI-ZEX 7000F” manufactured by Mitsui Petrochemical Industry Co., Ltd .; melt index (190 ° C., 2.16 kg load) is 0.04 g.
/ 10 min, density 0.956 g / cm ³ ]

PO-B : polyethylene [“HI-ZEX 5000H” manufactured by Mitsui Petrochemical Industry Co., Ltd .; 0.11 g of melt index (190 ° C., 2.16 kg load)
/ 10 min, density 0.960 g / cm ³ ]

PO-C : polyethylene [“MIRASON 102” manufactured by Mitsui Petrochemical Industries, Ltd .; melt index (190 ° C., 2.16 kg load) 0.35 g /
10 minutes, density 0.919 g / cm ³ ]

Example 1 A mixture consisting of 84 parts by weight of TPU-A, 16 parts by weight of POE-A and 5.3 parts by weight of PO-A was mixed with a single screw extruder (25 mmφ, cylinder temperature: 180 to 200).
And a die temperature: 200 ° C.) to produce a thermoplastic resin composition. Table 1 below shows the results of the evaluation of the thermoplastic resin composition by the above evaluation method.

Examples 2 to 5 The same method as in Example 1 except that the amounts of the thermoplastic polyurethane, ethylene-α-olefin copolymer and polyolefin resin were changed to the amounts shown in Table 1 below. Produced a thermoplastic resin composition. Table 1 below shows the results of the evaluation of the thermoplastic resin composition by the above evaluation method.

[0058]

[Table 1]

Comparative Examples 1 and 3-5 Same as Example 1 except that the amounts of the thermoplastic polyurethane, ethylene-α-olefin copolymer and polyolefin resin were changed to the amounts shown in Table 2 below. A thermoplastic resin composition was produced by the method described above. Table 2 below shows the results of the evaluation of the thermoplastic resin composition by the above evaluation method.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the amounts of the thermoplastic polyurethane, ethylene-α-olefin copolymer and polyolefin resin were changed to the amounts shown in Table 2 below. A plastic resin composition was manufactured. An attempt was made to produce a film having a thickness of 50 μm from this thermoplastic resin composition, but the film was cracked, and the film could be evaluated for blocking resistance, 100% modulus (M100), 50% recovery stress and residual strain. Was not obtained.

[0061]

[Table 2]

[0062]

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 articles such as films and sheets having excellent extensibility at low stress, high recovery stress after elongation, and small residual strain after elongation can be obtained with high yield and high yield. It can be manufactured with productivity.

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Claims (3)

[Claims] 1. A thermoplastic resin composition comprising (i) a thermoplastic polyurethane (a), an ethylene-α-olefin copolymer (b) and a polyolefin resin (c); (ii) a thermoplastic polyurethane (A) and ethylene-α
30 to 90% by weight of the thermoplastic polyurethane (a) and 70 to 10% by weight of the ethylene-α-olefin copolymer (b), based on the total weight of the olefin copolymer (b).
And 5 to 17% by weight of a polyolefin resin (c); and (iii) the thermoplastic polyurethane (a) has a number of hydroxyl groups per molecule of 2.01 to 2.10. And a thermoplastic polyurethane comprising a polymer polyol unit having a number average molecular weight of 500 to 8,000, an organic diisocyanate unit and a chain extender unit; (iv) the ethylene-α-olefin copolymer (b).
Has a molar ratio of ethylene units / α-olefin units of 75
(V) the polyolefin-based resin (c) has a melt index (190 ° C., 2.16 kg load) of from 0.01 to 25/95 to 95/5;
A thermoplastic resin composition, which is a polyolefin resin having a weight of 0.3 g / 10 minutes. 2. A molded article comprising the thermoplastic resin composition according to claim 1. 3. The molded article according to claim 2, wherein the molded article is a film or a sheet.