JP2019157006A - Thermoplastic resin composition and resin molded product - Google Patents

Abstract

To provide a thermoplastic resin composition including a modified polyester-based thermoplastic elastomer and an ethylene/vinyl alcohol copolymer that has high gas barrier property and moderate flexibility, does not deteriorate gas barrier property when formed into a stretched sheet or film, and is optimal for inflation molding.SOLUTION: The thermoplastic resin composition includes (A) a modified polyester-based thermoplastic elastomer produced by modifying (a) a polyester-based thermoplastic elastomer with an unsaturated carboxylic acid and/or a derivative thereof and (B) an ethylene/vinyl alcohol copolymer. In the thermoplastic resin composition, the modified polyester-based thermoplastic elastomer (A) has a melting peak temperature as measured by a differential scanning calorimeter of 170°C or higher and the modified polyester-based thermoplastic elastomer (A) has JIS-D hardness of 40 or more.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition. Specifically, the present invention relates to a thermoplastic resin composition containing a modified polyester thermoplastic elastomer and an ethylene-vinyl alcohol copolymer, a resin molded body comprising the thermoplastic resin composition, and a stretched resin molded body. It is related with the multilayer laminated body containing the layer which consists of a sheet-shaped or film-shaped molded object formed from this, and this thermoplastic resin composition.

  In general, an ethylene-vinyl alcohol copolymer resin (hereinafter referred to as “EVOH resin”) is a thermoplastic resin that has excellent oxygen non-permeability and mechanical strength, and is easy to mold. For films, sheets, and containers It is used in many applications such as materials, textile fibers, and pipes. However, EVOH resin is poor in flexibility and particularly inferior in impact resistance. In order to solve these problems, attempts have been made to improve the stretchability and flexibility of molded products by blending EVOH resin with other different resins.

  For example, polyester-based thermoplastic elastomers have flexibility, so they are used in a wide range of applications as vulcanized rubber substitute materials, are easy to mold, and have excellent low and high temperature characteristics. No. 1 describes a thermoplastic resin composition in which a modified polyester-based thermoplastic elastomer obtained by modifying a polyester-based thermoplastic elastomer with an unsaturated carboxylic acid or a derivative thereof is blended with an EVOH resin. It is described that a flat plate obtained by injection-molding the composition has high gas barrier properties and good flexibility and mechanical strength.

  Patent Document 2 and Patent Document 3 include other thermoplastic resin compositions in which a modified polyester thermoplastic elastomer obtained by modifying a polyester thermoplastic elastomer with an unsaturated carboxylic acid or a derivative thereof is mixed with EVOH resin. It is described that a multilayer laminate obtained by coextrusion molding or inflation molding with the above resin maintains a good appearance even when it is stretched.

JP 2004-002791 A JP-A-2005-111925 JP 2005-111926 A

  The molded object which consists of a thermoplastic resin composition of EVOH resin and a modified polyester thermoplastic elastomer described in Patent Documents 1 to 3 has gas barrier properties caused by blending other resins with EVOH resin. It is suitable for molding by various molding methods because of its high flexibility.

  However, when a sheet or a film-like molded body made of a thermoplastic resin composition of an EVOH resin and a modified polyester thermoplastic elastomer is stretched, the gas barrier property of the molded body after stretching is extremely worse than that before stretching. It has been found. In general, even when a molded body of EVOH resin alone is stretched, the gas barrier property of the molded body after stretching is inferior to that of the molded body before stretching, but the EVOH resin and modified polyester described in Patent Documents 1 to 3 In the case of a thermoplastic resin composition with a thermoplastic elastomer, the degree of deterioration is considerably greater than that of a molded body of EVOH resin alone.

  In addition, there is also a problem that a bent portion such as a nip portion is whitened when a molded body made of a thermoplastic resin composition of an EVOH resin and a modified polyester thermoplastic elastomer described in Patent Documents 1 to 3 is blown. It was.

  Accordingly, an object of the present invention is a thermoplastic resin composition containing a modified polyester thermoplastic elastomer and an ethylene-vinyl alcohol copolymer, which has a high gas barrier property, an appropriate flexibility, and a stretched sheet. It is an object of the present invention to provide a thermoplastic resin composition that does not deteriorate the gas barrier property even if it is made into a film and is optimal for inflation molding.

  In order to solve the above-mentioned problems, the present inventor has conducted intensive studies. As a result, the deterioration of the gas barrier property of the molded article after stretching is such that voids inside the resin composition become bubbles by stretching, which becomes pores. Identifying the cause, paying attention to the hardness and melting point of the modified polyester thermoplastic elastomer used for blending with EVOH resin, blending modified polyester thermoplastic elastomer and EVOH resin satisfying a certain hardness and melting point Since it is difficult to form bubbles inside the resin composition, voids are less likely to be generated inside the molded body even when stretched, and the extreme deterioration of the gas barrier properties of the molded body after stretching can be suppressed. It has been found that when the strength of the material is increased and the molded product produced by blow molding or the like is bent, the material destruction can be suppressed and whitening can be suppressed. It led to.

  That is, the gist of the present invention resides in [1] to [11].

[1] A modified polyester thermoplastic elastomer (A) obtained by modifying a polyester thermoplastic elastomer (a) with an unsaturated carboxylic acid and / or a derivative thereof, and an ethylene-vinyl alcohol copolymer (B). A thermoplastic resin composition containing the modified polyester-based thermoplastic elastomer (A) having a melting peak temperature of 170 ° C. or higher by a differential scanning calorimeter, and the modified polyester-based thermoplastic elastomer (A) JIS- A thermoplastic resin composition having a D hardness of 40 or more.

[2] The thermoplastic resin composition according to [1], wherein the polyester-based thermoplastic elastomer (a) contains a polyalkylene ether glycol segment.

[3] The thermoplastic resin composition according to [2], wherein the content of the polyalkylene ether glycol segment contained in the polyester-based thermoplastic elastomer (a) is 5 to 60% by mass.

[4] The thermoplastic resin composition according to any one of [1] to [3], wherein the modification of the polyester-based thermoplastic elastomer (a) is performed in the presence of a radical generator.

[5] In modification of the polyester thermoplastic elastomer (a), 0.01 to 30 parts by mass of an unsaturated carboxylic acid and / or a derivative thereof and a radical generator 0 with respect to 100 parts by mass of the polyester thermoplastic elastomer (a). The thermoplastic resin composition according to [4], wherein 0.001 to 3 parts by mass are used.

[6] The thermoplastic resin composition according to any one of [1] to [5], wherein the normalized modification rate of the modified polyester thermoplastic elastomer (A) is 0.01 to 15 (here, normalized) The modified rate represents the degree of modification of the modified polyester-based thermoplastic elastomer (A), and the standardized modified rate is obtained by the method described in this specification).

[7] The thermoplastic resin composition according to any one of [1] to [6], which satisfies the following condition (1).
(1) For a film having a thickness of 1000 μm or less molded from the thermoplastic resin composition, the oxygen gas permeability measured in accordance with JIS K7162-2 is 10 cm ³ / m ² · 24 hr · atm or less

[8] A resin molded article comprising the thermoplastic resin composition according to any one of [1] to [7].

[9] A sheet-like or film-like stretched molded product obtained by stretching the resin molded product according to [8].

[10] A layer composed of the thermoplastic resin composition according to any one of [1] to [7], and B layer composed of another thermoplastic resin composition laminated on one side or both sides of the A layer A multilayer laminate comprising:

[11] The multilayer laminate according to [10], wherein the other thermoplastic resin composition constituting the B layer is an adhesive resin for polyolefin, and further, a C layer made of a polyolefin resin is laminated on the B layer. .

  According to the thermoplastic resin composition of the present invention, since a high gas barrier property can be maintained even in a molded article after stretching, and whitening during inflation molding can be suppressed, a high-quality sheet or film-like molded article can be obtained by stretching. And the deterioration of workability and appearance can be effectively suppressed even in inflation molding.

  Hereinafter, embodiments of the present invention will be described in detail. The following embodiment is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to the following description. The present invention is not limited to the gist of the present invention. It can be implemented by being modified. In addition, in this specification, when a numerical value or a physical property value is inserted before and after using “to”, the value before and after that is used.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention comprises a modified polyester thermoplastic elastomer (A) obtained by modifying a polyester thermoplastic elastomer (a) with an unsaturated carboxylic acid and / or a derivative thereof, and an ethylene-vinyl alcohol copolymer. A thermoplastic resin composition comprising a polymer (B), wherein the modified polyester thermoplastic elastomer (A) has a melting peak temperature of 170 ° C. or higher measured by a differential scanning calorimeter, and the modified polyester thermoplastic The elastomer (A) has a JIS-D hardness of 40 or more.

<Modified polyester thermoplastic elastomer (A)>
The modified polyester-based thermoplastic elastomer (A) according to the present invention (hereinafter sometimes referred to as “modified polyester-based thermoplastic elastomer (A) of the present invention”) is a polyester containing an unsaturated carboxylic acid and / or a derivative thereof. It can be obtained by modifying the thermoplastic elastomer (a). In the modification, a radical generator is preferably used. In this modification reaction, it is considered that a graft reaction in which an unsaturated carboxylic acid and / or a derivative thereof is added to the polyester-based thermoplastic elastomer (a) mainly occurs. It is considered that a reaction in which an unsaturated carboxylic acid and / or a derivative thereof is added to the terminal, a transesterification reaction, a decomposition reaction, or the like also occurs.

  As the polyester thermoplastic elastomer (a), those using aromatic polyester as a hard segment and polyalkylene ether glycol or aliphatic polyester as a soft segment are preferable. In particular, a polyester polyether block copolymer using a polyalkylene ether glycol as a soft segment is preferable. Among them, the content of the polyalkylene ether glycol component in the block copolymer is 5 to 60% by mass, preferably 5 to 50% by mass. %, More preferably 5 to 45% by mass. If the content of the polyalkylene ether glycol component in the block copolymer exceeds 60% by mass, the hardness may not be exhibited, or a surface layer peeling phenomenon may occur in the injection molded product, and if the content is less than 5% by mass Elastomeric properties may decrease, resulting in insufficient flexibility and impact resistance, and surface peeling may occur in injection molded products. The content of the polyalkylene ether glycol component can be calculated based on the chemical shift of the hydrogen atom and its content using NMR.

  The polyester polyether block copolymer includes i) an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, ii) an aromatic and / or aliphatic dicarboxylic acid or an alkyl ester thereof, and iii) A polycondensation of an oligomer obtained by esterification or transesterification using a polyalkylene ether glycol having a number average molecular weight of 400 to 6,000 as a raw material is preferably used.

  Examples of the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms include those generally used as raw materials for polyesters, particularly polyester elastomers, such as ethylene glycol, propylene glycol, Examples include methylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. Among them, 1,4-butanediol and ethylene glycol are preferable, and 1,4-butanediol is particularly preferable. preferable. These diols can be used as one kind or a mixture of two or more kinds.

  As the aromatic dicarboxylic acid, those generally used as raw materials for polyesters, particularly polyester elastomers, can be used. For example, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, and the like can be used. Among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferable, and terephthalic acid is particularly preferable. These aromatic dicarboxylic acids can be used as one kind or a mixture of two or more kinds.

  As the aromatic dicarboxylic acid alkyl ester, dimethyl ester or diethyl ester of the above aromatic dicarboxylic acid is used, and among them, dimethyl terephthalate and 2,6-dimethyl naphthalene dicarboxylate are preferable.

  The aliphatic dicarboxylic acid is preferably cyclohexane dicarboxylic acid, and the aliphatic dicarboxylic acid alkyl ester is preferably dimethyl ester or diethyl ester of cyclohexane dicarboxylic acid.

  In addition to the above components, a small amount of trifunctional alcohol, tricarboxylic acid or ester thereof may be copolymerized, and aliphatic dicarboxylic acid such as adipic acid or dialkyl ester thereof can also be used as a copolymerization component.

  As the polyalkylene ether glycol, those having a number average molecular weight of usually 400 to 6,000, preferably 500 to 4,000, particularly preferably 600 to 3,000 are used. When the number average molecular weight is less than 400, the block property of the copolymer is insufficient, and when the number average molecular weight is more than 6,000, phase separation tends to occur in the system and the physical properties of the polymer tend to be lowered. Here, the number average molecular weight means that measured by gel permeation chromatography (GPC). For calibration of GPC, for example, POLYTETRAHYDROFURAN calibration kit manufactured by POLYMER LABORATORIES, UK can be used.

  Specific examples of the polyalkylene ether glycol include polyethylene glycol, poly (1,2- and / or 1,3-propylene ether) glycol, poly (tetramethylene ether) glycol, poly (hexamethylene ether) glycol and the like. Is done.

  Examples of commercially available polyester elastomers include “Primalloy” manufactured by Mitsubishi Chemical Corporation, “Perprene” manufactured by Toyobo Co., Ltd., “Hytrel” manufactured by Toray DuPont Co., Ltd., and the like.

  Examples of unsaturated carboxylic acids and / or derivatives thereof used for modification include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid; 2-octen-1-yl anhydride, 2-dodecen-1-yl succinate, 2-octadecen-1-yl succinate, maleic anhydride, 2,3-dimethylmaleic anhydride, Bromomaleic anhydride, dichloromaleic anhydride, citraconic anhydride, itaconic anhydride, 1-butene-3,4-dicarboxylic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, 1, 2,3,6-tetrahydrophthalic anhydride, 3,4,5,6, -tetrahydrophthalic anhydride, exo-3,6-epoxy-1 2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, endo-bicyclo [2.2.2] Unsaturated carboxylic acid anhydrides such as oct-5-ene-2,3-dicarboxylic acid anhydride and bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid anhydride Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2- (meth) acrylic acid 2- Ethylhexyl, lauryl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, dimethyl maleate, maleic acid (2-ethylhexyl , And unsaturated carboxylic acid esters such as 2-hydroxyethyl (meth) acrylate. Of these, unsaturated carboxylic acid anhydrides are preferred. In the present specification, the expression “(meth) acryl” means “acryl or methacryl”.

  These unsaturated carboxylic acids and / or derivatives thereof can be appropriately selected according to the copolymer containing the polyalkylene ether glycol segment to be modified and the modification conditions, and two or more of them can be used in combination. Good. The unsaturated carboxylic acid and / or derivative thereof may be added after being dissolved in an organic solvent or the like.

  The amount of the unsaturated carboxylic acid and / or derivative thereof used for modification is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyester-based thermoplastic elastomer (a). More preferably, it is 0.1 to 1 part by mass. If the blending amount of the unsaturated carboxylic acid and / or derivative thereof is 0.01 parts by mass or more, sufficient modification can be performed, and the obtained modified polyester thermoplastic elastomer (A) and ethylene-vinyl alcohol can be combined. Good compatibility can be obtained by blending the polymer (B), and the occurrence of a surface peeling phenomenon on the surface of an injection molded product of a thermoplastic resin composition obtained by blending the polymer (B) is prevented. If the blending amount of the unsaturated carboxylic acid and / or derivative thereof is 30 parts by mass or less, the viscosity of the resulting modified polyester thermoplastic elastomer (A) upon melting is suppressed, and this is an ethylene-vinyl alcohol copolymer. The moldability of the thermoplastic resin composition obtained by blending (B) is improved.

  In the present invention, radical generators used for the modification include t-butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2. , 5-bis (tert-butyloxy) hexane, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxybenzoate, benzoyl peroxide, dicumyl peroxide, 1,3-bis (tert-butylperoxyisopropyl) benzene, Organic and inorganic peroxides such as dibutyl peroxide, methyl ethyl ketone peroxide, potassium peroxide, hydrogen peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (isobutylamide) dihalide, 2,2 ′ Azobis [2-methyl-N (2-hydroxyethyl) propionamide], azo compounds such as azodi -tert- butane, and carbon radical generators such as dicumyl are exemplified.

  The radical generator can be appropriately selected according to the type of the polyester-based thermoplastic elastomer (a) used for the modification treatment, the type of the unsaturated carboxylic acid and / or its derivative, and the modification conditions, and two or more types can be selected. May be used in combination. The radical generator can also be added after being dissolved in an organic solvent or the like.

  The amount of the radical generator used for modification is preferably 0.001 to 3 parts by mass, more preferably 0.005 to 0.5 parts by mass, and still more preferably 100 parts by mass of the polyester-based thermoplastic elastomer (a). Is 0.01 to 0.2 parts by mass, particularly preferably 0.01 to 0.1 parts by mass. If the blending amount of the radical generator is 0.001 part by mass or more, the modification has occurred sufficiently, and the resulting modified polyester thermoplastic elastomer (A) and ethylene-vinyl alcohol copolymer (B) are blended. Sufficient compatibility can be obtained, and the occurrence of the delamination phenomenon on the surface of the injection molded product of the obtained thermoplastic resin composition is prevented. If the blending amount of the radical generator is 3 parts by mass or less, the viscosity of the resulting modified polyester thermoplastic elastomer (A) when melted is suppressed, and this is blended with the ethylene-vinyl alcohol copolymer (B). The moldability of the thermoplastic resin composition obtained in this way becomes good.

  The modification method for obtaining the modified polyester thermoplastic elastomer (A) using the polyester thermoplastic elastomer (a), the modified polyester thermoplastic elastomer (A) and the radical generator includes a melt-kneading reaction method, a solution Various known reaction methods such as a reaction method and a suspension dispersion reaction method can be used, and among them, a melt-kneading reaction method is preferable.

  When modifying by melt kneading reaction method, using a Henschel mixer, ribbon blender, V-type blender, etc., polyester-based thermoplastic elastomer (a) and unsaturated carboxylic acid and / or derivative thereof at a predetermined blending ratio After the radical generator is uniformly mixed, the mixture is melt-kneaded using an ordinary kneader such as a Banbury mixer, a kneader, a roll, a multi-screw kneading extruder such as a single screw or a twin screw. If necessary, an unsaturated carboxylic acid and / or derivative thereof and a radical generator may be dissolved in an organic solvent and used for the reaction.

  The melt-kneading is usually carried out in the range of 100 ° C to 300 ° C, preferably 120 ° C to 280 ° C, and particularly preferably 150 ° C to 250 ° C so that the resin is not thermally deteriorated.

  The modified polyester-based thermoplastic elastomer (A) of the present invention has a JIS-D hardness (hardness according to durometer type D measured according to JIS K6253) of 40 or more, preferably 45 or more, more preferably 50 or more. When the JIS-D hardness of the modified polyester thermoplastic elastomer (A) is less than 40, the gas barrier property when the thermoplastic resin composition using the modified polyester resin is stretched is deteriorated or the molded product is formed by inflation molding. There is a possibility that whitening may occur at the bent portion of the.

  The melting peak temperature of the modified polyester thermoplastic elastomer (A) of the present invention measured by a differential scanning calorimeter is 170 ° C. or higher, preferably 180 ° C. or higher, more preferably 200 ° C. or higher. When the melting peak temperature of the modified polyester-based thermoplastic elastomer (A) is less than 170 ° C., the gas barrier property when the thermoplastic resin composition using the modified polyester resin is stretched is deteriorated or the molded product is formed by inflation molding. There is a possibility that whitening may occur at the bent portion of the. In addition, the upper limit of the melting peak temperature of the modified polyester thermoplastic elastomer (A) is usually about 220 ° C. because the effect may be reduced from the viewpoint of softening the ethylene-vinyl alcohol copolymer.

The degree of modification of the modified polyester thermoplastic elastomer (A) of the present invention is determined by the infrared absorption spectrum method described below, and is calculated by the following formula (1) (hereinafter referred to as “normalized modification rate”). "Is preferably 0.01 to 15, more preferably 0.03 to 2.5, still more preferably 0.1 to 2.0, and particularly preferably 0.2 to 1.8. If the standardized modification rate is 0.01 or more, the above-mentioned surface layer peeling hardly occurs, and if it is 15 or less, the mechanical strength can be maintained.
Normalized denaturation rate = A ₁₇₈₆ / (Ast × r) (1)

In the formula (1), A ₁₇₈₆ is a peak intensity measured at a wave number of 1786 cm ⁻¹ for a 20 μm-thick film made of the modified polyester thermoplastic elastomer (A), and As is a standard sample (polyalkylene ether glycol) It is a peak intensity measured at a standard wave number for a film having a thickness of 20 μm made of a saturated polyester elastomer having a segment content of 65% by mass. As the reference wave number, a wave number that is not affected by denaturation and has no absorption peak that overlaps in the vicinity thereof is selected. r is a value obtained by dividing the mole fraction of the polyester segment in the modified polyester thermoplastic elastomer (A) by the mole fraction of the polyester segment in the standard sample, and is 1 in the standard sample.

Specifically, the standardized modification value of the modified polyester thermoplastic elastomer (A) is determined by the following method. That is, a film-like sample having a thickness of 20 μm is dried under reduced pressure at 100 ° C. for 15 hours to remove unreacted substances, and then an infrared absorption spectrum is measured. Absorption peak due to stretching vibration of carbonyl group derived from an acid anhydride appearing at a wave number of 1786 cm ⁻¹ on the obtained spectrum (tangent line connecting the mountain hems on both sides of the absorption band in the range of 1750 to 1820 cm ⁻¹ is defined as the baseline. The peak height is calculated as “peak intensity A ₁₇₈₆ ”. On the other hand, an infrared absorption spectrum is similarly measured for a film having a thickness of 20 μm made of a standard sample (saturated polyester elastomer having a polyalkylene ether glycol segment content of 65 mass%). In the case of an aromatic polyester-based elastomer containing a benzene ring on the obtained spectrum, for example, an absorption peak (850 to 900 cm ⁻¹⁾ due to an out-of-plane variation angle of C—H of the benzene ring appearing at 872 cm ⁻¹ as a peak of the standard wave number. The peak height is calculated as “peak intensity As” by using a tangent line connecting the mountain hems on both sides of the absorption band in the range of (5) as the base line.

From the obtained peak intensity A ₁₇₈₆ and peak intensity As, a standardized denaturation rate is calculated according to equation (1). r is a value obtained by dividing the mole fraction of the polyester segment in the modified polyester elastomer by the mole fraction of the polyester segment in the standard sample as described above, and the mole fraction mr of the polyester segment in each sample is It calculates | requires by following formula (2) from the weight fraction (w1 and w2) of a polyester segment and a polyalkylene ether glycol segment, and the molecular weight (e1 and e2) of the monomer unit which comprises both segments.
mr = (w1 / e1) / [(w1 / e1) + (w2 / e2)] (2)

  The thermoplastic resin composition of the present invention may contain one type of the modified polyester thermoplastic elastomer (A), and contains two or more types having different types and physical properties of the constituent components. Also good.

<Ethylene-vinyl alcohol copolymer (B)>
The ethylene-vinyl alcohol copolymer (EVOH resin) (b) constituting the thermoplastic resin composition of the present invention is usually obtained by saponifying an ethylene-vinyl acetate copolymer. As the EVOH resin (B), a copolymer having an ethylene content of usually 10 to 70 mol%, preferably 20 to 60 mol%, and a saponification rate of a vinyl acetate component of 95 mol% or more is suitable. If the ethylene content is 10 mol% or more, the gas barrier property in a high humidity state is likely to be sufficient, and if it is 70 mol% or less, sufficient gas barrier property can be obtained. Further, when the degree of saponification is 95 mol% or more, gas barrier properties, moisture resistance and thermal stability can be sufficiently obtained.

  The melt flow rate (MFR) (JIS K7210, 230 ° C., load 2.16 kg) of the EVOH resin (B) is preferably 0.5 to 100 g / 10 minutes, particularly 1 to 60 g / 10 minutes. If the MFR is 0.5 g / 10 min or more, the moldability is excellent and the appearance of the resulting molded product tends to be good, and if it is 100 g / 10 min or less, sufficient gas barrier properties can be obtained.

  The modified polyester thermoplastic elastomer (A) of the present invention may contain one type of EVOH resin (B), or may contain two or more types having different physical properties such as ethylene content and MFR. Good.

<Blending ratio of modified polyester thermoplastic elastomer (A) and EVOH resin (B)>
The content of the modified polyester thermoplastic elastomer (A) and EVOH resin (B) contained in the thermoplastic resin composition of the present invention is a total of 100 of the modified polyester thermoplastic elastomer (A) and EVOH resin (B). It is preferable that the content of the modified polyester thermoplastic elastomer (A) is 5 to 95% by mass and the content of the EVOH resin (B) is 95 to 5% by mass with respect to 5% by mass. More preferably, the content of the plastic elastomer (A) is 5 to 45% by mass, the content of the EVOH resin (B) is 95 to 55% by mass, and the content of the modified polyester thermoplastic elastomer (A) is More preferably, the content of the EVOH resin (B) is 5 to 30% by mass and 95 to 70% by mass.
By including the modified polyester thermoplastic elastomer (A) and the EVOH resin (B) in the above range, a thermoplastic resin composition excellent in balance among flexibility, impact resistance and gas barrier properties can be obtained.
If the EVOH resin (B) content is low and the modified polyester thermoplastic elastomer (A) is too much, the gas barrier property becomes insufficient, and conversely, the EVOH resin (B) is large and the modified polyester thermoplastic elastomer (A ) Is too small, flexibility cannot be obtained and impact resistance is also lowered. In addition, within the range of the blending ratio of the EVOH resin (B), the blending ratio of the EVOH resin (B) can be further selected depending on the application. For example, when desired for flexibility, high impact resistance, and appropriate gas barrier properties, a relatively large amount of the modified polyester thermoplastic elastomer (A) may be blended.

<Other ingredients>
In the thermoplastic resin composition of the present invention, other than the above-described modified polyester thermoplastic elastomer (A) and EVOH resin (B), other objects may be used depending on the purpose within a range not impairing the objects and effects of the present invention. Resin component, rubber component, talc, calcium carbonate, mica, glass fiber filler, plasticizer such as paraffin oil, antioxidant, heat stabilizer, light stabilizer, UV absorber, neutralizer, lubricant, anti-fogging Add one or more kinds of any additional compounding materials such as agents, anti-blocking agents, slip agents, cross-linking agents, cross-linking aids, coloring agents, flame retardants, dispersants, antistatic agents, antibacterial agents, and fluorescent brightening agents can do. Among them, it is preferable to add one or more antioxidants such as phenol, phosphite, thioether, and aromatic amine.

<Method for producing thermoplastic resin composition>
The thermoplastic resin composition of the present invention is, for example, modified polyester thermoplastic elastomer (A) and EVOH resin (B), if necessary, as in the case of modifying the above-mentioned polyester thermoplastic elastomer (a). It is obtained by blending the additional blending material in a predetermined ratio, mixing thoroughly, and then melt-kneading. Further, when modifying the polyester thermoplastic elastomer (a), in addition to the polyester thermoplastic elastomer (a), the unsaturated carboxylic acid and / or derivative thereof, and a radical generator, an EVOH resin (B) is blended, The thermoplastic resin composition can be simultaneously produced from the modified polyester thermoplastic elastomer (A) and EVOH resin (B) produced by modification of the thermoplastic elastomer (a). Usually, a method in which the modified polyester thermoplastic elastomer (A) is first produced and then kneaded with the EVOH resin (B) is preferable from the viewpoint of obtaining a thermoplastic resin composition exhibiting more excellent characteristics. .

<Physical properties of thermoplastic resin composition>
The thermoplastic resin composition of the present invention has excellent gas barrier properties. In particular, the EVOH resin (B) has a blending ratio of 70 to 95% by mass with respect to a total of 100% by mass of the modified polyester thermoplastic elastomer (A) and the EVOH resin (B), and more excellent gas barrier properties. Become.
The gas barrier property of the thermoplastic resin composition of the present invention is determined by the measurement method shown in the examples described later in accordance with JIS K7162-2 for a film having a thickness of 1000 μm or less molded from the thermoplastic resin composition of the present invention. The measured oxygen gas permeability is preferably 10 cm ³ / m ² · 24 hr · atm or less, more preferably 1 cm ³ / m ² · 24 hr · atm or less, particularly preferably 0.5 cm ³ / m ² · 24 hr · atm or less. It is.

The thermoplastic resin composition of the present invention has excellent transparency. In particular, the blending ratio of the EVOH resin (B) is more excellent in transparency at 70 to 95% by mass with respect to 100% by mass in total of the modified polyester thermoplastic elastomer (A) and the EVOH resin (B). Become.
The transparency of the thermoplastic resin composition of the present invention is preferably 10% or less, more preferably 8 as the haze measured in accordance with JIS K7105 for a film having a thickness of 20 μm comprising the thermoplastic resin composition of the present invention. % Or less, particularly preferably 6% or less.

  The thermoplastic resin composition of the present invention has excellent impact resistance. In particular, the impact resistance is higher when the blending ratio of the modified polyester thermoplastic elastomer (A) is 1 to 45% by mass with respect to 100% by mass in total of the modified polyester thermoplastic elastomer (A) and the EVOH resin (B). It will be excellent.

[Resin moldings and stretch moldings]
There is no particular limitation on the method of molding the resin molded body of the present invention using the thermoplastic resin composition of the present invention, and molding can be performed by a conventional method such as injection molding, extrusion molding, vacuum molding, or hollow molding. it can.

  Further, the resin molded body comprising the thermoplastic resin composition of the present invention may be further stretched to form a sheet-like or film-like molded body. In this case, the stretching method is not particularly limited, and is in accordance with a conventional method. It can be carried out.

  For example, after cooling and solidifying the unstretched resin molded product of the present invention, it is reheated to a stretching temperature of 80 to 200 ° C. in-line or offline, and uniaxially or biaxially using a tenter, a plug, compressed air, etc. Examples of the method include obtaining a stretch-molded body such as a film or sheet that is stretched at least 4 times in area ratio and uniaxially or biaxially stretch-molded. As a draw ratio, it is 4-50 times normally by area ratio, Preferably it is 5-20 times. If the draw ratio is less than 2 times, the above-mentioned effect of stretching cannot be obtained, and if it exceeds 60 times, the strength of the stretched molded product tends to decrease, such as breakage during molding.

  In the case of producing an inflation film, a method such as a simultaneous biaxial stretching method for inflation, a tenter simultaneous biaxial stretching method in the case of a T-die film, and a sequential biaxial stretching method based on a roll and a tenter can be used.

  In addition, the stretched molded product of the present invention can be further improved in heat resistance (however, shrinkage is slightly reduced) by performing reheating after stretching, that is, heat setting, as necessary. Moreover, the stretched molded product of the present invention and a separately produced film or sheet can be laminated to form a laminate.

  The resin molded body and stretched molded body produced from the thermoplastic resin composition of the present invention can be used as various industrial parts and packaging materials because of their excellent gas barrier properties, transparency, and impact resistance. Specifically, it can be preferably used for food packaging containers, medical packaging containers, retort containers, and the like. Moreover, it can be used as an automobile interior part, an automobile exterior part, an automobile functional part, a home appliance part, an electric device, an electronic part, an electric wire, a building material, a sporting article, a daily necessities, a fiber, a tube, and the like.

[Multilayer laminate]
When producing a film, sheet, bottle, pipe or the like using the thermoplastic resin composition of the present invention, it may be used alone or as a multilayer laminate combined with other materials. Moreover, the thermoplastic resin composition of the present invention can also be used as an adhesive layer of a multilayer laminate. When used as an adhesive layer of a multilayer laminate, a multilayer comprising an A layer composed of the thermoplastic resin composition of the present invention and a B layer composed of another thermoplastic resin composition laminated on one or both sides of the A layer A laminate is preferred. Other thermoplastic resin compositions constituting the B layer include polyester, a thermoplastic resin composition containing the polyester, or a polyester-based thermoplastic elastomer resin, an adhesive resin for polyolefin, an EVOH resin, or a heat containing EVOH resin. A plastic resin composition is exemplified.

  In particular, the multilayer laminate having a structure in which the other thermoplastic resin composition constituting the B layer is made of a polyester resin, preferably a polyethylene terephthalate resin, and the B layer is laminated on both sides of the A layer has an excellent function. It is useful for various films, sheets, bottles and the like.

  Examples of the polyester resin constituting the B layer include thermoplastic polyesters produced by condensing dicarboxylic acid or its lower alkyl ester, acid halide, anhydride and other derivatives with glycol.

  Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, p-carboxyphenoacetic acid, p, p'-dicarboxydiphenyl. P, p′-dicarboxydiphenylsulfone, p-carboxyphenoxyacetic acid, p-carboxyphenoxypropionic acid, p-carboxyphenoxybutyric acid, p-carboxyphenoxyvaleric acid, p-carboxyphenoxyhexanoic acid, p, p′-di Carboxydiphenylmethane, p, p′-dicarboxydiphenylpropane, p, p′-dicarboxydiphenyloctane, 3-alkyl-4- (β-carboxyethoxy) -benzoic acid, 2,6-naphthalene dicarboxylic acid and 2,7 -Naphthalene dicarboxylic acid, etc. Is exemplified group and aliphatic dicarboxylic acids, these dicarboxylic acids may be used as a mixture of two or more kinds, among them terephthalic acid is particularly preferred.

  Examples of the glycol include those having 2 to 12 carbon atoms such as ethylene glycol, 1,3-propylene glycol, 1,6-hexylene glycol, 1,10-decamethylene glycol, and 1,12-dodecamethylene glycol. Examples are alicyclic glycols such as chain alkylene glycol and 1,4-cyclohexanedimethanol. Moreover, you may substitute a part or all of the said linear alkylene glycol by aromatic glycols, such as p-xylylene glycol, pyrocatechol, resorcinol, hydroquinone, or the alkyl substituted derivative of these compounds. Among these, preferred glycols are linear alkylene glycols having 2 to 4 carbon atoms.

  As the polyester resin constituting the B layer, polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate are preferable, and polyethylene terephthalate is particularly preferable. Commercial products of such polyester resins include “Novapex” manufactured by Mitsubishi Chemical Corporation, “Novadour” manufactured by Mitsubishi Engineering Plastics Co., Ltd., “Duranex” manufactured by Polyplastics Co., Ltd., Eastman Chemical Co., Ltd. ) “PET-G” and the like are exemplified.

  The multilayer laminate of the present invention is a B comprising the thermoplastic resin composition containing the above-described modified polyester thermoplastic elastomer (A) of the present invention on one or both sides of the A layer comprising the thermoplastic resin composition of the present invention. A layer may be laminated. In this case, the thermoplastic resin composition constituting the B layer can have the same configuration as the thermoplastic resin composition of the present invention except that it does not contain the EVOH resin (B). Hereinafter, the thermoplastic resin composition containing the modified polyester thermoplastic elastomer (A) and not containing the EVOH resin (B) may be referred to as the “adhesive thermoplastic resin composition of the present invention”.

  Such a multilayer laminate of the present invention can be produced by various conventionally known methods. For example, a coextrusion molding method in which the thermoplastic resin composition of the present invention that constitutes the A layer and another thermoplastic resin composition that constitutes the B layer are coextruded, a sheet comprising the thermoplastic resin composition of the present invention, A method of extruding and laminating another thermoplastic resin composition constituting the B layer on the film (A layer), and conversely, a book comprising the A layer on a sheet or film (B layer) comprising the other thermoplastic resin composition. The method of extrusion laminating the thermoplastic resin composition of the invention is mentioned.

  Furthermore, inflation molding method, blow molding method, rotational molding method, press molding method, injection molding method (insert injection molding method, two-color injection molding method, core back injection molding method, sandwich injection molding method, injection press molding method), etc. The multilayer laminate of the present invention can also be produced using various molding methods.

  The molded body produced from the multilayer laminate of the present invention can be used, for example, as various industrial parts and packaging materials. Specifically, it can be preferably used for food packaging containers, medical packaging containers, retort containers, and the like. Also used as automotive interior parts, automotive exterior parts, automotive functional parts, home appliance parts, electrical equipment, electronic parts, electric wires, building materials, sports equipment, daily necessities, textiles, stretched or unstretched films, sheets, bottles, pipes, tubes, etc. can do.

  When producing a film, sheet, bottle, pipe or the like using the multilayer laminate of the present invention, the adhesive heat of the present invention laminated on one side or both sides of the A layer comprising the thermoplastic resin composition of the present invention. A C layer made of a base resin may be laminated on a B layer made of a plastic resin composition. The B layer comprising the adhesive thermoplastic resin composition of the present invention containing the modified polyester thermoplastic elastomer (A) of the present invention exhibits good adhesion to various resins. Therefore, various resins can be used as the base resin constituting the C layer. Polyester, a thermoplastic resin composition containing the polyester, or a polyester-based elastomer resin, a polyamide resin, a polystyrene resin, a polycarbonate resin, an EVOH resin, or The thermoplastic resin composition containing EVOH resin is illustrated.

  In particular, a multilayer laminate in which the other thermoplastic resin composition constituting the C layer is a polyester resin, preferably a polyethylene terephthalate resin, has an excellent function and is useful for various films, sheets, bottles and the like.

  Examples of the polyester resin constituting the C layer include the thermoplastic polyester described as the polyester resin constituting the B layer.

  In addition, a multilayer laminate in which a D layer made of an adhesive resin for polyolefin is laminated on the surface of the A layer where the B layer is not laminated, and an E layer made of a polyolefin resin is laminated on the D layer has an excellent function. It is useful for various films, sheets, bottles, pipes and the like. In particular, C layer composed of a base resin / B layer composed of an adhesive thermoplastic resin composition of the present invention / A layer composed of a thermoplastic resin composition of the present invention / D layer composed of an adhesive resin for polyolefin / polyolefin resin The multi-layer laminate of 5 types and 5 layers comprising the E layer is suitably used for the above-mentioned applications.

  The polyolefin adhesive resin constituting the D layer is usually composed of a modified polyolefin resin. Such a modified polyolefin resin is produced by copolymerizing and / or graft-polymerizing an α, β-unsaturated carboxylic acid and / or a derivative thereof to a polyolefin resin mainly composed of an ethylene component and / or a propylene component.

  Examples of the polyolefin resin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ethylene-ethylacrylic acid. Examples thereof include a copolymer and an ethylene-sodium acrylate copolymer.

  Examples of the α, β-unsaturated carboxylic acid and / or its derivative to be copolymerized include acrylic acid, methacrylic acid, methyl methacrylic acid, sodium acrylate, zinc acrylate, vinyl acetate, glycidyl methacrylate, and the like. It may be copolymerized in the molecular chain in a range of 40 mol% or less. Examples of the copolymer-modified polyolefin resin include an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-ethyl acrylic acid copolymer, and an ethylene-sodium acrylate copolymer.

  Examples of the grafted α, β-unsaturated carboxylic acid and / or derivative thereof include, for example, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid or acid anhydrides thereof, or of these acids. Examples include esters. Among these modifying compounds, maleic anhydride is particularly preferably used. The graft amount is selected from the range of 0.01 to 25% by weight, preferably 0.05 to 1.5% by weight, based on the polyolefin resin.

  The graft reaction is carried out according to a conventional method, for example, by melt-mixing a polyolefin resin and an α, β-unsaturated carboxylic acid and / or derivative thereof at a resin temperature of 150 to 300 ° C. In the graft reaction, 0.001 to 0.05% by weight of an organic peroxide such as α, α'-bis-t-butylperoxy-p-diisopropylbenzene is blended in order to perform the reaction efficiently.

  Examples of the polyolefin-based resin constituting the E layer include ethylene, propylene, and 1-butene, which are α-olefins having 2 to 4 carbon atoms, or crystalline polymers containing these as main components. Specific examples of these polyolefins include polyethylene, polypropylene, and poly-1-butene, but these are not limited to homopolymers, and as long as these olefins are the main component, other 2 carbon atoms. -20 α-olefin or a copolymer with vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid and styrene, and unsaturated carboxylic acids such as maleic anhydride, maleic acid and acrylic acid. A graft copolymer graft-modified with an acid or a derivative thereof may also be used. Furthermore, these polyolefins may be a mixture. Moreover, the crosslinked polyolefin resin which bridge | crosslinked these polyolefin resin may be sufficient.

Specific examples of the polyethylene include, for example, high pressure method low density polyethylene (LDPE), ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene polymer, ethylene-1- Examples include hexene copolymers, high density polyethylene (HDPE), ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, and the like. Among these, LDPE, ethylene-α-olefin random copolymer, ethylene-vinyl acetate copolymer, and the like are preferable because they are excellent in transparency and low-temperature heat sealability, and in particular, the density is 0.910 to 0.960 g / cm. ³ and a melting point in the range of 100 to 135 ° C are preferred. The melt flow rate (MFR) of polyethylene (JIS K2710, 190 ° C., load 2.16 kg) is not particularly limited, but is usually 0.01 to 30 g / 10 minutes, preferably 0.1, from the viewpoint of moldability. The range is from 10 to 10 g / 10 minutes.

  Specific examples of the polypropylene include propylene random copolymers such as polypropylene (propylene homopolymer), propylene-ethylene random copolymer, propylene-ethylene-1-butene random copolymer, and propylene-1-butene random copolymer ( Propylene content is usually 90 mol% or more, preferably 95 mol% or more), propylene-ethylene block copolymer (ethylene content is usually 5 to 30 mol%). Among these, a homopolymer and a random copolymer are preferable from the viewpoint of excellent transparency, and a random copolymer having a melting point of 130 to 140 ° C. is particularly preferable because of excellent heat sealability. The melt flow rate (MFR) (JIS K2710, 230 ° C., load 2.16 kg) of polypropylene is not particularly limited, but is usually 0.5 to 30 g / 10 minutes, preferably 0.5 from the viewpoint of moldability. The range is from 10 to 10 g / 10 minutes.

  Specific examples of the poly 1-butene include 1-butene homopolymer, 1-butene-ethylene copolymer, 1-butene-propylene copolymer and 1-butene-4-methyl-1-pentene copolymer. Is exemplified. The melt flow rate (MFR) of poly-1-butene (JIS K2710, 230 ° C., load 2.16 kg) is not particularly limited, but is preferably 0.01 to 100 g / 10 min from the viewpoint of moldability. Is in the range of 0.03 to 30 g / 10 min.

  As a method for producing a multilayer laminate having the above-mentioned C layer, D layer and E layer, the thermoplastic resin composition of the present invention constituting the multilayer laminate of the present invention and the adhesive thermoplastic resin composition of the present invention And other thermoplastic resin compositions, a method of extruding and laminating other molten thermoplastic resin compositions to sheets and films based on the multilayer laminate of the present invention, and vice versa A method of extrusion laminating the molten multilayer laminate of the present invention to a sheet or film of the resin composition is mentioned. Moreover, you may dry-laminate other thermoplastic resins using an adhesive agent to the sheet | seat and film of the multilayer laminated body of this invention.

  The multilayer laminate of the present invention can be formed into a stretched laminate, a tube, a pipe, a bottle and the like by various forming methods. The production of each molded body will be described below.

Production of stretched laminate:
By stretching the multilayer laminate of the present invention to obtain a stretched laminate (hereinafter sometimes referred to as “stretched laminate of the present invention”), B layer (adhesive layer) has better fusing properties. Can be demonstrated. Various conventionally known methods can be employed as a method for producing the stretched laminate. For example, after cooling and solidifying the unstretched multilayer laminate (sheet or film) obtained as described above, it is reheated to a stretching temperature of 60 to 160 ° C. inline or offline, and a tenter, plug, compressed air, etc. It is possible to obtain a molded body such as a film, a cup, a bottle or the like that is stretched by 1.5 times or more in an area ratio in a uniaxial direction or a biaxial direction by using it. As a draw ratio, it is 1.5-50 times normally by area ratio, Preferably it is 1.5-20 times. If the draw ratio is less than 1.5 times, the effect of better adhesion of the adhesive layer by drawing cannot be obtained, and if the draw ratio exceeds 50 times, breakage may occur at the time of molding. The strength tends to decrease.

  Specifically, in the case of an inflation film, it can be produced by the inflation simultaneous biaxial stretching method or the like, and in the case of a T-die film, it can be produced by a tenter simultaneous biaxial stretching method or a sequential biaxial stretching method using a roll and a tenter. In the case of manufacturing a cup, it can be manufactured by a compressed air molding method using only compressed air or the like in a mold, or an SPPF molding method using a plug and compressed air in combination.

  Further, the stretched laminate of the present invention is further improved in heat resistance (reduced shrinkage slightly) by performing reheating after stretching, that is, heat setting, as necessary. Moreover, the stretched laminate of the present invention and a separately produced film can be laminated to form a laminate.

Tube manufacturing:
As a method for forming a multilayer tube using the multilayer laminate of the present invention, the thermoplastic resin composition of the present invention that constitutes each layer, the adhesive thermoplastic resin composition of the present invention, and other thermoplastic resins or resin compositions And the method of co-extrusion. The multilayer tube manufactured by the above method is excellent in low temperature impact resistance, transparency, bending fatigue resistance and gas barrier properties, and is a medical or quasi-drug tube, wasabi, face wash, toothpaste, hand cream, etc. It can be used as a tube for grocery products such as mustard and ginger.

Pipe manufacturing:
As a method for forming a multilayer pipe using the multilayer laminate of the present invention, the thermoplastic resin composition of the present invention constituting the multilayer laminate of the present invention, the adhesive thermoplastic resin composition of the present invention and other thermoplastics The method of co-extrusion with a resin composition is mentioned. The multilayer pipe manufactured by the above method is excellent in low-temperature impact resistance, bending fatigue resistance, and gas barrier properties, and can be used as floor heating, water supply / hot water supply, and industrial pipe.

Manufacturing bottles by blow molding:
Using the multilayer laminate of the present invention, for example, using the multilayer laminate of the present invention, for example, a three-layer laminate structure of B layer / A layer / B layer or C layer / B layer / A layer / B layer / After forming into a preform by injection molding so as to have a 5-layer laminated structure of C layer, by stretch blow molding, by blow molding a parison molded by extrusion molding, or by vertically stacking the laminated pipe After the stretching, the bottle can be produced by a pipe stretching method in which the film is stretched in the transverse direction with compressed air or the like in the mold. The obtained multilayer bottle has excellent gas barrier properties, impact resistance, and transparency, and can be used as a container for liquid seasonings such as carbonated beverages, alcoholic beverages, soy sauce, sauces, mirin, and dressings. Furthermore, it can use suitably as drink containers, such as fruit juice drinks, tea, and mineral water, by heat-setting.

  Hereinafter, although the specific aspect of this invention is demonstrated in detail using an Example, this invention is not limited by a following example, unless the summary is exceeded.

[raw materials]
The raw materials of the resin composition used in Examples, Comparative Examples and Reference Examples are as follows.

<Modified polyester thermoplastic elastomer (A)>
A-1: Maleic anhydride-modified aromatic polyester-based thermoplastic elastomer "Modic GQ730" manufactured by Mitsubishi Chemical Corporation
A-2: Maleic anhydride-modified aromatic polyester-based thermoplastic elastomer Synthetic product A-3: Maleic anhydride-modified aromatic polyester-based thermoplastic elastomer "Modic GQ131" manufactured by Mitsubishi Chemical Corporation
A-4: Maleic anhydride-modified aromatic polyester-based thermoplastic elastomer “Modic GQ430” manufactured by Mitsubishi Chemical Corporation
The physical properties of the maleic anhydride-modified polyester thermoplastic elastomer are summarized in Table 1 below.

<Ethylene-vinyl alcohol copolymer (B)>
B-1: EVOH resin “Soarnol DC3203RB” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
Ethylene content 32 mol%
MFR 3.8 g / 10 min (temperature 230 ° C., load 2.16 kg)
B-2: EVOH resin “EVAL H171B” manufactured by Kuraray Co., Ltd.
Ethylene content 38 mol%
MFR 3.5g / 10min (temperature 230 ° C, load 2.16kg)

[Evaluation of the physical properties]
In Examples, Comparative Examples, and Reference Examples, physical properties of the obtained films were evaluated by the following methods.
(1) Oxygen gas permeability About the film (before stretching) formed by <film formation of resin composition> and the stretched film (after stretching) obtained by <molding of stretched film>, in accordance with JIS K7162-2, temperature 23 ° C. using MOCON Inc. the "OX-TRAIN 2/21", humidity 50% RH, and measured under the conditions of the transmission area 50 cm ² or 5 cm ^2. In addition, a measurement lower limit (ND) is 0.01 cm < ³ > / (m < ² > 24h * atm).
(2) Evaluation of whitening at the time of film folding The film formed by <film forming of resin composition> was cut into 100 mm in length and 100 mm in width, and the degree of whitening was visually confirmed by bending it into a cross at positions of 50 mm in length and width. In addition, “○” indicates that no whitening is observed, and “X” indicates that the material is clearly whitened.

[Example 1]
<Film molding of resin composition>
10 parts by weight of maleic anhydride-modified aromatic polyester-based thermoplastic elastomer (A-1) and 90 parts by weight of EVOH resin (B-1) were converted into a twin screw extruder “KZW15” (screw diameter 15 mmφ, Extruded at a set temperature of 220 to 240 ° C. and a rotational speed of 100 to 200 rpm at the same direction biaxial L / D = 45), and with a 150 mmφ cooling roll, the roll temperature is 40 to 60 ° C. and the line speed is 1 to 10 m / min. A film having a thickness shown in Table 2 was obtained.

<Formation of stretched film>
Using the tenter type biaxial stretching device (manufactured by Toyo Seiki), the film obtained above was biaxially stretched in a ratio of length × width of 3 × 3 and stretched films having the thicknesses shown in Table 2 Got. The stretching conditions were a preheating temperature of 80 to 180 ° C., a preheating time of 10 seconds, and a stretching speed of 3 to 4 m / min.

  The evaluation results of the obtained film are shown in Table 2.

[Example 2, Comparative Examples 1 to 3, Reference Examples 1 and 2]
Except that the resin composition raw material composition was changed as shown in Table 2, film formation and stretching were performed in the same manner as in Example 1 (however, in Comparative Examples 1 and 2 only film formation).
The evaluation results of the obtained film are shown in Table 2.

Table 2 shows the following.
In Comparative Examples 1 and 2 using the modified polyester thermoplastic elastomer (A) having a low melting peak temperature and low JIS-D hardness, there is a problem of whitening. In Comparative Example 3, the gas barrier property is remarkably lowered by stretching.
On the other hand, in Examples 1 and 2 using the modified polyester thermoplastic elastomer (A) whose melting peak temperature and JIS-D hardness satisfy the provisions of the present invention, the gas barrier property is excellent even after stretching and the problem of whitening Nor.
In the above examples, the presence or absence of whitening was evaluated for the extruded film. However, since whitening is not observed when the extruded film is folded, it is considered that the problem of whitening does not occur even if inflation molding is performed. .
Reference Examples 1 and 2 using only the EVOH resin (B) have excellent gas barrier properties and no whitening problem, but EVOH resins are inferior in flexibility.

Claims (11)

  Thermoplastic containing modified polyester thermoplastic elastomer (A) obtained by modifying polyester thermoplastic elastomer (a) with unsaturated carboxylic acid and / or derivative thereof, and ethylene-vinyl alcohol copolymer (B) A resin composition, wherein the modified polyester-based thermoplastic elastomer (A) has a melting peak temperature of 170 ° C. or higher by a differential scanning calorimeter, and the modified polyester-based thermoplastic elastomer (A) has a JIS-D hardness of A thermoplastic resin composition characterized by being 40 or more.   The thermoplastic resin composition according to claim 1, wherein the polyester-based thermoplastic elastomer (a) contains a polyalkylene ether glycol segment.   The thermoplastic resin composition according to claim 2, wherein the content of the polyalkylene ether glycol segment contained in the polyester-based thermoplastic elastomer (a) is 5 to 60% by mass.   The thermoplastic resin composition according to any one of claims 1 to 3, wherein the modification of the polyester-based thermoplastic elastomer (a) is performed in the presence of a radical generator.   In modification | denaturation of a polyester-type thermoplastic elastomer (a), 0.01-30 mass parts of unsaturated carboxylic acid and / or its derivative, and radical generator 0.001-100 mass parts of polyester-type thermoplastic elastomer (a). The thermoplastic resin composition according to claim 4, wherein 3 parts by mass is used.   The standardized modification rate of the modified polyester-based thermoplastic elastomer (A) is 0.01 to 15. The thermoplastic resin composition according to any one of claims 1 to 5, wherein the standardized modification rate is This represents the degree of modification of the modified polyester-based thermoplastic elastomer (A), and the normalized modification rate is determined by the method described in this specification.). The thermoplastic resin composition according to any one of claims 1 to 6, which satisfies the following condition (1).
(1) For a film having a thickness of 1000 μm or less molded from the thermoplastic resin composition, the oxygen gas permeability measured in accordance with JIS K7162-2 is 10 cm ³ / m ² · 24 hr · atm or less   The resin molding which consists of a thermoplastic resin composition in any one of Claims 1-7.   A sheet-like or film-like stretched molded product obtained by stretching the resin molded product according to claim 8.   A multilayer laminate comprising an A layer comprising the thermoplastic resin composition according to claim 1 and a B layer comprising another thermoplastic resin composition laminated on one or both sides of the A layer. .   The multilayer laminate according to claim 10, wherein another thermoplastic resin composition constituting the B layer is an adhesive resin for polyolefin, and a C layer made of a polyolefin resin is further laminated on the B layer.