JPH07331060A - Thermoplastic resin composition and film comprising the same - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition having the same degrees of excellent elastic recovery, strength and flexibility as those of a thermoplastic polyurethane and improved film-forming stability. CONSTITUTION:A thermoplastic resin composition comprises (A) a prescribed thermoplastic polyurethane and (B) a specific aromatic vinyl compound- conjugated diene block copolymer [the weight ratio of the component A/B=>=30/70]. The component A is a polyurethane having 55-85 hardness (JIS A) obtained by reacting a polyester diol comprising 1,9-nonanediol and 2- methyl-1,8-octanediol components as diol components having the ratio of 1,9- nonanediol/2-methyl-1,8-octanediol of 80/20-0/100 and 1,300-5,000 number-average molecular weight with an organic diisocyanate and a chain extender. The component B is an aromatic vinyl compound-conjugated diene block copolymer having 5-50 wt. of the aromatic vinyl composition content and <=30 MFR (200 deg.C, 5kg).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic resin composition comprising a specific thermoplastic polyurethane and a specific aromatic vinyl compound-conjugated diene block copolymer, and a film comprising the resin composition. The thermoplastic resin composition of the present invention is excellent in elastic recovery, strength and elongation, heat resistance, flexibility and film forming property. The film of the present invention effectively exhibits the features of the resin composition and is useful as a stretchable film.

[0002]

2. Description of the Related Art Thermoplastic polyurethanes have elastic recoverability,
Although it has excellent performance in terms of strength and flexibility, it is a relatively expensive resin. On the other hand, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene /
Polyolefin resins such as methyl acrylate copolymer and aromatic vinyl compound resins such as polystyrene are cheaper than thermoplastic polyurethane. Therefore, in order to inexpensively obtain a thermoplastic resin material that retains the excellent properties of the thermoplastic polyurethane, it has been attempted to blend the thermoplastic polyurethane with a polyolefin resin or an aromatic vinyl compound resin.

However, the thermoplastic polyurethane is incompatible with the polyolefin resin and the aromatic vinyl compound resin, and when they are simply blended, the dispersed state is not good. Probably because of this, when a resin composition of thermoplastic polyurethane and a polyolefin resin or an aromatic vinyl compound resin is subjected to film forming, there is a problem that film forming stability is low and it is difficult to form a thin film. This difficulty in forming a thin film becomes particularly remarkable when the thermoplastic polyurethane is flexible. Further, even in a film obtained from a resin composition of a thermoplastic polyurethane and a polyolefin-based resin or an aromatic vinyl compound-based resin, there is a problem that performance such as elastic recovery, strength, heat resistance and flexibility is insufficient. is there. In addition, attempts have been made to blend other components or introduce a functional group into a part of the resin composition to improve the dispersion state of the polyolefin resin or the aromatic vinyl compound resin and improve various physical properties. There is. However, even in that case, there is still a problem that elasticity recovery and heat resistance are insufficient.

[0004]

One of the objects of the present invention is that it is composed of a thermoplastic polyurethane and another thermoplastic resin, is cheaper than the thermoplastic polyurethane, and has an excellent elastic recovery property which the thermoplastic polyurethane has. Another object of the present invention is to provide a thermoplastic resin composition which retains heat resistance and strength and elongation, has high film-forming stability, and can be formed into a thin film. Another object of the present invention is to provide a film made of thermoplastic polyurethane and another thermoplastic resin and having excellent elastic recovery, heat resistance, strength and elongation, and flexibility.

[0005]

According to the present invention, one of the above objects is to provide a thermoplastic resin composition comprising a thermoplastic polyurethane and an aromatic vinyl compound-conjugated diene block copolymer. The weight ratio of the aromatic vinyl compound-conjugated diene block copolymer is 3
0/70 or more, the thermoplastic polyurethane is 1,
A 9-nonanediol and a 2-methyl-1,8-octanediol component were used as diol components, and a 1,9-nonanediol / 2-methyl-1,8-octanediol molar ratio was 80/20 to 0/100. Some number average molecular weight 130
A hardness (JI) obtained by reacting 0 to 5000 polyester diol, an organic diisocyanate and a chain extender.
S-A) 55 to 85 polyurethane, and the aromatic vinyl compound-conjugated diene block copolymer has an aromatic vinyl compound component content of 5 to 50% by weight and a melt flow rate (200 ° C, 5 kg). It is achieved by providing a thermoplastic resin composition characterized by being an aromatic vinyl compound-conjugated diene block copolymer having 30 or less. Further, according to the present invention, the above-mentioned other object is achieved by providing a film made of the above thermoplastic resin composition.

Thermoplastic polyurethane is generally obtained by reacting a polymeric diol, an organic diisocyanate and a chain extender. In the present invention, 1,9-nonanediol and 2-methyl-1,2 are used as the polymeric diol.
Using 8-octanediol as a diol component, a polyester diol having a number average molecular weight of 1300 to 5000 and a molar ratio of 1,9-nonanediol / 2-methyl-1,8-octanediol of 80/20 to 0/100 is used. It is important to.

The polyester diol used in the present invention is
It has a 1,9-nonanediol and a 2-methyl-1,8-octanediol component as at least a part of the diol component. When a polyester diol having no 1,9-nonane diol and a 2-methyl-1,8-octane diol component as the diol component is used, the resulting thermoplastic polyurethane is prepared from the aromatic vinyl compound-conjugated diene block copolymer. Even if it is mixed with the polymer to form a resin composition, the resulting resin composition may have a large dispersed particle diameter of the aromatic vinyl compound-conjugated diene block copolymer, or may be elastic recovery, heat resistance, strength, and flexibility. Property becomes insufficient, and film forming stability becomes poor.
Also, by adding other components or introducing functional groups,
When the dispersed particle size of the aromatic vinyl compound-conjugated diene block copolymer in the resin composition becomes relatively small, elastic recovery, strength and flexibility are improved, but high elastic recovery is required. In this case, its elastic recovery property is insufficient, and improvement in heat resistance is not sufficient.

Generally, the higher the proportions of 1,9-nonanediol and 2-methyl-1,8-octanediol components in the diol component, the better the elastic recovery, strength and flexibility of the resulting resin composition. Therefore, 20 mol% or more of the diol component is preferably 1,9-nonanediol and 2-methyl-1,8-octanediol component, and 40 mol% or more of 1,9-nonanediol and It is more preferably a 2-methyl-1,8-octanediol component. When the molar ratio of 1,9-nonanediol / 2-methyl-1,8-octanediol is not in the range of 80/20 to 0/100, the elastic recovery and flexibility of the obtained resin composition are poor, which is not preferable. When the molar ratio of 1,9-nonanediol / 2-methyl-1,8-octanediol is in the range of 80/20 to 0/100, elastic recovery, heat resistance, strength and flexibility of the obtained resin composition are obtained. Excellent, but the molar ratio is 80/20
In the range of up to 20/80, the effect becomes more remarkable.

As described above, the diol component in the polyester diol of the present invention may be composed of 1,9-nonanediol and 2-methyl-1,8-octanediol component and other diol components. . 1,9
Examples of the diol component that may be contained together with the nonanediol and the 2-methyl-1,8-octanediol component include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, Neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,
Examples thereof include diol components derived from saturated aliphatic diols such as 10-decanediol, and two or more types of these diol components may be contained. Furthermore, in the polyester diol in the present invention, a trifunctional or higher functional polyol component may coexist as long as the flexibility of the resulting thermoplastic resin composition is not deteriorated. The content of the trifunctional or higher functional polyol component is preferably 5 mol% or less based on the total diol components.

Examples of the dicarboxylic acid component which constitutes the polyester diol together with the diol component include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid,
Derived from a dicarboxylic acid such as 2-methylsuccinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctanedioic acid or its ester-forming derivative (eg, esterified product) A dicarboxylic acid component is included.

The number average molecular weight of the polyester diol used in the present invention is 1300 to 5000. When the number average molecular weight is less than 1300, the properties such as elastic recovery, heat resistance and strength and elongation of the resulting resin composition are insufficient. On the other hand, when the number average molecular weight exceeds 5,000, the moldability becomes insufficient such that the melt viscosity of the resulting thermoplastic resin composition tends to increase during extrusion molding, which is not preferable.

The method for producing the polyester diol used in the present invention is not particularly limited. Therefore, the polyester diol can be produced by a method similar to the known method used in the production of polyesters such as polyethylene terephthalate and polybutylene terephthalate, that is, transesterification or direct esterification followed by melt polycondensation reaction. . In the polycondensation reaction, a titanium-based or tin-based polycondensation catalyst may be used. However, when a titanium-based polycondensation catalyst is used, it is preferable to deactivate the polycondensation catalyst in the obtained polyester diol after the polycondensation reaction. By deactivating the polycondensation catalyst, it is possible to suppress the deterioration of the block property of the hard segment and the soft segment, which gradually occurs while the obtained thermoplastic polyurethane is molten and retained at a high temperature,
The heat resistance that the thermoplastic polyurethane originally had even in the film obtained from the resin composition by the melt extrusion molding method,
Various properties such as elastic recovery are effectively exhibited.

As a method for deactivating the polycondensation catalyst in the polyester diol, contact treatment with water is preferable. For example, 1 to 4% by weight of water is added to the polyester diol, and the mixture is stirred at 80 to 150 ° C. It is possible to employ a method of stirring at 100 to 150 ° C. while passing water vapor through the polyester diol. In addition, the polycondensation catalyst can be deactivated by adding a phosphorus compound which is generally used for deactivating the catalyst of polyester.

In the present invention, it is preferable to use the above polyester diol alone as the polymer diol, but if desired, other polymer diols (for example, polycarbonate diol, polyether diol, polyester other than the above polyester diol) may be used. Diol etc.) may be used together. The amount of the other polymer diol used is preferably 30% by weight or less based on the whole polymer diol.

As the organic diisocyanate used in the present invention, 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4 '
Examples are the organic diisocyanates known to be commonly used in polyurethane production, such as dicyclohexylmethane diisocyanate. Among these,
4,4'-diphenylmethane diisocyanate is preferred.

Further, in the present invention, as the chain extender,
Chain extenders known to be commonly used in polyurethane production can be used. As the chain extender, a low molecular weight compound having a molecular weight of 300 or less and containing at least two hydrogen atoms capable of reacting with an isocyanate group (-NCO) in the molecule is preferable. As examples thereof, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (2
Examples include diols such as -hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate and xylylene glycol. These chain extenders may be used alone or in admixture of two or more. Among these chain extenders, 1,
4-Butanediol is particularly preferred.

In the production of polyurethane, based on the total amount of active hydrogen atoms (that is, hydrogen atoms capable of reacting with isocyanate groups) of the polymer diol and the chain extender, isocyanate per mole of active hydrogen atoms is used. The number of moles of the group is 0.90 to 1.30, preferably
It is preferable to use the organic diisocyanate in a ratio such that it is 0.95 to 1.30.

As a method for producing a thermoplastic polyurethane by reacting a polymer diol, an organic diisocyanate and a chain extender, known techniques for urethanization reaction such as melt polymerization and solution polymerization can be adopted. Among them, it is preferable to carry out melt polymerization in the substantial absence of a solvent, and particularly preferable is a continuous melt polymerization method using a multi-screw extruder. The melt polymerization temperature is not particularly limited,
It is preferably 180 ° C. or higher and 260 ° C. or lower.

In addition, a colorant,
Various additives such as flame retardants, UV absorbers, antioxidants, hydrolysis resistance improvers, antifungal agents; various fibers such as glass fibers and polyester fibers; inorganic substances such as mica and talc; various coupling agents, etc. You may select suitably and may add.

In particular, the effect of preventing blocking between films at the time of film formation is great, it can be wound up without using release paper, and the elastic recovery, heat resistance and strength of the film obtained by adding it and from the viewpoint of flexibility does not drop, the general formula ^{(I), R 1 -CO-} NH-R 2 -NH-CO-R 3 (I) ( in formula, R ^1, R ³ is an alkyl group, R ² is A compound represented by (which represents an alkylene group) is preferably blended in an amount of 0.3 to 5% by weight based on the thermoplastic resin composition. From the viewpoints of the effect of preventing blocking, the compatibility with the thermoplastic resin composition, the melting point of the compound, etc., R ¹ and R ³ in the formula (I) are alkyl groups having 6 to 35 carbon atoms, and R ² is the carbon number. 1-9 alkylene groups are preferred. More preferably, R ¹ and R ³ are alkyl groups having 10 to 35 carbon atoms, and R ² is an alkylene group having 1 to 6 carbon atoms.

It is important that the thermoplastic polyurethane used in the present invention has a hardness (JIS-A) in the range of 55 to 85. When the hardness exceeds 85, the flexibility of the obtained thermoplastic resin composition becomes insufficient, and when the hardness is less than 55, the elastic recovery, heat resistance and strength of the obtained thermoplastic resin composition. It is not preferable because the above becomes insufficient.

Aromatic vinyl compound used in the present invention
The conjugated diene block copolymer contains 5 to 50% by weight of an aromatic vinyl compound component and has a melt flow rate (200 ° C., 5 kg) of 30 or less. The block copolymer contains one or more, preferably two or more, polymer blocks mainly containing an aromatic vinyl compound component, and further contains one or more polymer blocks mainly containing a conjugated diene compound component. It is a thing.

When the content of the aromatic vinyl compound component in the block copolymer exceeds 50% by weight, the obtained thermoplastic resin composition has the aromatic vinyl compound-conjugated diene block copolymer particles dispersed therein. It is not preferable because the elastic recovery property, the strength, etc. are deteriorated, probably because the particle size is large. On the other hand, when the content of the aromatic vinyl compound component is less than 5% by weight, disadvantages such as increase in tackiness of the film formed from the thermoplastic resin composition occur, which is not preferable.

When the melt flow rate (200 ° C., 5 kg) of the block copolymer exceeds 30, the dispersion state of the aromatic vinyl compound-conjugated diene block copolymer in the thermoplastic resin composition is poor. In addition, elastic recovery, heat resistance, strength and flexibility are reduced, and film formation becomes difficult. Elastic recovery of the resulting thermoplastic resin composition,
From the point that strength, flexibility and film-forming property are particularly good,
The melt flow rate of the aromatic vinyl compound-conjugated diene block copolymer is preferably 10 or less, and 5
The following is more preferable. The lower limit of the melt flow rate is not particularly limited, but is preferably 0.1 or more.

Examples of the aromatic vinyl compound component constituting the block copolymer include components derived from aromatic vinyl compounds such as styrene, α-methylstyrene and vinyltoluene. Examples of the conjugated diene compound component include components derived from a conjugated diene compound such as isoprene, butadiene, and 1,3-pentadiene.

In the thermoplastic resin composition of the present invention,
The mixing ratio of the thermoplastic polyurethane having the specific structure to the specific aromatic vinyl compound-conjugated diene block copolymer is 30 by weight ratio of thermoplastic polyurethane / aromatic vinyl compound-conjugated diene block copolymer. /
It is important that it is 70 or more. When the weight of the thermoplastic polyurethane is less than 30% by weight based on the total weight of the thermoplastic polyurethane and the aromatic vinyl compound-conjugated diene block copolymer, the elastic recovery property is higher than that of the thermoplastic polyurethane alone. However, it is not preferable because properties such as heat resistance and strength are largely deteriorated. From the viewpoint that properties such as elastic recovery, strength, and heat resistance are particularly good, the weight ratio of the thermoplastic polyurethane / aromatic vinyl compound-conjugated diene block copolymer is preferably 50/50 or more.

From the viewpoint of the performance of the obtained resin composition, the upper limit of the weight ratio of thermoplastic polyurethane / aromatic vinyl compound-conjugated diene block copolymer is not particularly limited. From the aspect of the invention, the weight ratio of the thermoplastic polyurethane / aromatic vinyl compound-conjugated diene block copolymer is preferably set to 90/10 or less because it does not suit the purpose of the present invention.

The thermoplastic resin composition of the present invention can be produced by a usual polymer blending method except that the thermoplastic polyurethane and the aromatic vinyl compound-conjugated diene block copolymer are used. For example, the above-mentioned thermoplastic polyurethane and aromatic vinyl compound-conjugated diene block copolymer were pre-mixed at a predetermined ratio using a vertical or horizontal mixer which is usually used for mixing resin materials. After that, it is produced by kneading under heating in a batch system or a continuous system using a single-screw or twin-screw extruder, a mixing roll, a Banbury mixer and the like. Upon mixing, light resistance, stabilizer for improving heat resistance, plasticizer, lubricant such as aliphatic amide, filler,
You may add additives, such as an antistatic agent and a pigment, in the quantity which does not impair the effect of this invention.

As a method for producing a film from the thermoplastic resin composition of the present invention, a usual film forming method by melt extrusion molding such as inflation molding and T die molding can be adopted. As the conditions for melt extrusion molding, suitable conditions can be appropriately selected and adopted.

The above-mentioned specific thermoplastic polyurethane and aromatic vinyl compound constituting the thermoplastic resin composition of the present invention
With the conjugated diene block copolymer, minute particles of the aromatic vinyl compound-conjugated diene block copolymer can be uniformly dispersed in the matrix of the thermoplastic polyurethane simply by mixing them under melting conditions. Therefore, when a film is produced from the thermoplastic resin composition of the present invention, the film-forming stability is good and the film can be made thin.
Further, the obtained film is excellent in elastic recovery property, heat resistance, strength and elongation and flexibility, and in particular, the effect of improving elastic recovery property and heat resistance is large, and the aromatic vinyl compound-conjugated diene block copolymer is fine. The effect is more than the dispersed effect.

[0031]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, the elastic recovery property, heat resistance, strength, film-forming property, and blocking prevention property between films during film-forming were evaluated by the following methods.

[Elastic recovery] A test piece prepared from a film having a thickness of 50 μm formed by using a T-die was subjected to a pulling speed of 200 at a temperature of 23 ° C. and a humidity of 65% RH.
250m elongation at mm / min, hold for 2 minutes, then 200m
An elongation-stress curve when returning to the original length at a speed of m / min was obtained, and the residual strain at the position where the stress was zero was used as an index of elastic recovery.

[Heat resistance] Film thickness of 5 using T-die
The dynamic viscoelasticity of a test piece prepared from a 0 μm film was measured at a frequency of 11 Hz, and the end temperature on the high temperature side of the rubber-like flat region of the dynamic storage elasticity E ′ was used as an index of heat resistance.

[Strength] Film thickness 50 formed by using T-die
The tensile elongation of the test piece prepared from the film having a thickness of μm was measured by performing a tensile test under conditions of a tensile speed of 200 mm / min, a temperature of 23 ° C. and a humidity of 65% RH.

[Flexibility] Film thickness of 5 using T-die
With respect to the 0 μm film, the flexibility (feel) was evaluated by the feel of the hand according to the following criteria. ◯: It is soft without any mess. Δ: Slightly stiff and slightly lacking in softness. X: Rigid, lacking in softness, unsuitable as a stretch film.

[Film Formability] Film-forming properties were evaluated by using a T-die with films having various thicknesses, and the film-forming properties were evaluated according to the following criteria. ◯: A film having a film thickness of 30 μm or less and 20 μm can be stably formed. Δ: It is difficult to form a film having a film thickness of 30 μm or less, but a film having a film thickness larger than 30 μm can be stably formed. ×: Even a film having a film thickness of 100 μm cannot be stably formed.

[Anti-blocking property between films during film formation] A T-die was used to pass a cooling roll adjusted to 30 ° C., the film was wound up without using release paper, and the film was evaluated according to the following criteria. The antiblocking property during the period was evaluated. A: The film can be easily rewound after the film formation. ◯: The film can be rewound after film formation, but a slight tensile force is required. Δ: The film can be rewound after film formation, but a considerable tensile force is required. X: The film cannot be easily rewound after the film formation.

In the examples, the compounds are represented by the abbreviations shown in Table 1 below.

[Table 1]

[Reference Example 1] (Production of polyester diol A) 192 kg of ND / MOD (molar ratio: 65/35) and 146 kg of AD were charged in a reactor, and nitrogen gas was passed through the system under atmospheric pressure to about 220 ° C. At the temperature of 1, the esterification reaction was carried out while distilling the produced water out of the system. When the acid value of the produced polyester is 30 or less, tetraisopropyl titanate is added to the mixture, and 200-100 mmHg
The polycondensation reaction was continued under reduced pressure. When the acid value reached 1.0, the degree of vacuum was gradually raised by a vacuum pump to complete the reaction. As a result, 293 kg of polyester diol having a number average molecular weight of 2000 (this is referred to as "polyester diol A") was obtained.

[Reference Example 2] (Production of polyester diol B) ND / MOD (molar ratio: 65/35) and AD were charged into a reactor, and esterification reaction and polycondensation reaction were carried out in the same manner as in Reference Example 1, A polyester diol having a number average molecular weight of 4000 was obtained. The obtained polyester diol is 100 ° C.
The mixture was heated to 3% by weight of water and stirred at the same temperature for 2 hours to deactivate the titanium catalyst, and then the water was distilled off under reduced pressure. By this treatment, a polyester diol in which the titanium catalyst was deactivated (this is referred to as "polyester diol B") was obtained.

Reference Examples 3 and 4 (Production of Polyester Diols C and D) Esters were the same as in Reference Example 1 except that the diol used was BD (Reference Example 3) or ND (Reference Example 4). The polyesterification reaction and the polycondensation reaction were performed to obtain a polyester diol having a number average molecular weight of 2,000. The obtained polyester diol was inactivated in the same manner as in Reference Example 2 to deactivate the titanium catalyst. By this treatment, polyester diols in which the titanium catalyst was deactivated (these are referred to as "polyester diol C or D") were obtained. The compositions of these polyester diols are shown in Table 2.

[0042]

[Table 2]

[Reference Example 5] {Production of Polyurethane P} Polyester diol A, MDI and BD obtained in Reference Example 1 had a polyester diol A / MDI / BD molar ratio of 1 / 2.40 / 1.40. And a speed at which the total amount of these becomes 300 g / min, a twin-screw extruder (30 mmφ; L / D = 36; cylinder temperature: about 200 per block, which rotates in the coaxial direction by a metering pump. (Set in the range of 0 ° C to about 250 ° C) was continuously charged to carry out continuous melt polymerization reaction. The resulting thermoplastic polyurethane melt was continuously extruded in strands into water, then cut with a pelletizer and formed into pellets. The pellets were dehumidified and dried at 80 ° C. for 20 hours to obtain a thermoplastic polyurethane having a hardness (JIS-A) of 75 (this is referred to as “polyurethane P”).

[Reference Examples 6 to 9] {Polyurethane Q to T]
Manufacture of} The polyester diol obtained in Reference Examples 2 to 4 was used in place of the polyester diol A, and the molar ratio of polyester diol / MDI / BD was changed to the ratio shown in Table 3 and Reference Example 5 was used. Similarly, continuous melt polymerization reaction, pelletization, and dehumidification drying are performed to obtain thermoplastic polyurethane (these are referred to as “polyurethane Q ...
T "). The hardness (JIS-A) of these thermoplastic polyurethanes is also shown in Table 3.

[0045]

[Table 3]

Example 1 70 wt% of the thermoplastic polyurethane P obtained in Reference Example 5 was added with 21 wt% of styrene component content (hereinafter abbreviated as “St content”) and melt flow rate (200 ° C., 5 kg). (Hereinafter abbreviated as "MFR") 3
A thermoplastic resin composition was produced by melt-kneading 30% by weight of SIS at dg / min with a 25 mmφ extruder (cylinder temperature and die temperature: 205 ° C.). The formed thermoplastic resin composition was extruded from a T die and wound through a cooling roll to obtain a film having a thickness of 50 μm. The wound film required a considerable amount of tensile force, but could be rewound. The film for measuring the physical properties was wound with release paper sandwiched between them. We also tried to reduce the thickness to 20 μm, but
The film could be stably formed even at m. The obtained film having a thickness of 50 μm was allowed to stand at 25 ° C. for 7 days, and then elastic recovery, strength and elongation, and heat resistance were evaluated. The evaluation results are shown in Table 4 below.

[Examples 2 to 5, Comparative Examples 1 to 7] Thermoplastic polyurethane, aromatic vinyl compound-conjugated diene block copolymer and ESBA were melt-kneaded in the same manner as in Example 1 in the combinations shown in Table 4. Then, a film having a thickness of 50 μm made of the thermoplastic resin composition was obtained by forming a film. In addition, the film for measuring the physical properties,
It was wound up with a release paper sandwiched between them. Each of the obtained films was allowed to stand in the same manner as in Example 1 and then evaluated. The results are shown in Table 4 together with the film-forming properties at the time of film-forming and blocking prevention properties.

[0048]

[Table 4]

From Table 4 above, Examples 1-5 according to the present invention
The thermoplastic resin composition provides a film having excellent film-forming stability, elastic recovery, heat resistance, strength and flexibility, and in particular, it uses a polyester diol that has been subjected to a deactivation treatment of a polycondensation catalyst. It can be seen that in Examples 2 to 5 using the thermoplastic polyurethane produced by the above, the elastic recovery property, heat resistance, strength and flexibility of the film are further improved. Further, when a fatty acid bisamide is blended, it is excellent in blocking prevention during film formation. On the other hand, the thermoplastic resin compositions of Comparative Examples 1 to 7, which are different from the present invention,
The film-forming property is unstable, and only a film having inferior elastic recovery, strength and heat resistance can be obtained, and the blocking property during film-forming is large.

[0050]

According to the present invention, a thermoplastic resin composition having excellent elastic recovery, heat resistance, strength and flexibility possessed by thermoplastic polyurethane is provided. Furthermore, by blending a fatty acid bisamide, a thermoplastic resin composition having excellent blocking prevention during film formation is provided. Since the aromatic vinyl compound-conjugated diene block copolymer is blended with the thermoplastic polyurethane, the thermoplastic resin composition is less expensive than the thermoplastic polyurethane alone. The film of the present invention effectively exhibits the characteristics of the thermoplastic resin composition and is useful as a stretchable film.

Claims (3)

[Claims] 1. A thermoplastic resin composition comprising a thermoplastic polyurethane and an aromatic vinyl compound-conjugated diene block copolymer, wherein a weight ratio of thermoplastic polyurethane / aromatic vinyl compound-conjugated diene block copolymer is 30 /. 70 or more, the thermoplastic polyurethane,
The 1,9-nonanediol and 2-methyl-1,8-octanediol components were used as diol components, and the molar ratio of 1,9-nonanediol / 2-methyl-1,8-octanediol was 80/20 to 0 /. Number average molecular weight of 1 is 1
A polyurethane having a hardness (JIS-A) of 55 to 85 obtained by reacting 300 to 5000 polyester diol, an organic diisocyanate and a chain extender, and the aromatic vinyl compound-conjugated diene block copolymer is an aromatic A thermoplastic resin composition, which is an aromatic vinyl compound-conjugated diene block copolymer having a vinyl compound component content of 5 to 50% by weight and a melt flow rate (200 ° C., 5 kg) of 30 or less. 2. The thermoplastic resin composition according to claim 1, wherein R ¹ —CO—NH—R ² —NH—CO—R ³ (wherein R ¹ and R ³ are alkyl groups, R ² Represents an alkylene group) in an amount of 0.3 to 5% by weight. 3. A film made of the thermoplastic resin composition according to claim 1.