JP2020196790A - Ethylene-vinyl alcohol resin composition, and molding and multilayered structure including the same - Google Patents

Abstract

To provide an EVOH resin composition that suppresses decrease in tensile elasticity and yield strength, without causing bleedout, and has improved resin fluidity.SOLUTION: An ethylene-vinyl alcohol copolymer resin composition has an ethylene-vinyl alcohol copolymer (A), and an additive (B) that is an additive (B1) composed of a fluorene derivative or an additive (B2) composed of a carboxylic acid amide derivative, the additive (B) content of 0.01-20 mass%.SELECTED DRAWING: None

Description

The present invention relates to a resin composition having good fluidity without bleeding out of additives, and a molded product and a multilayer structure using the same.

The ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as "EVOH") has excellent gas barrier properties and organic solvent resistance derived from vinyl alcohol units, and melt moldability and water resistance derived from ethylene units. It is a crystalline polymer and has a wide range of applications.

According to Patent Document 1, a resin composition having an additive composed of a specific hydroxyl group-containing compound in an ethylene-vinyl alcohol copolymer has a high oxygen barrier property, a low glass transition temperature, and no bleed-out. , It is stated that a highly flexible resin molded body can be realized.

WO2015 / 163437

However, the additives used in the invention described in Patent Document 1 are 1,1,1-trimethylolpropane and the like, and these additives contribute to improving the fluidity of EVOH (lowering the melting point). At the same time, there is a problem that the tensile elastic modulus and the yield strength are lowered.

An object of the present invention is to provide an EVOH resin composition in which bleed-out does not occur, a decrease in tensile elastic modulus and yield strength is suppressed, and the fluidity of the resin is improved.

That is, the present invention includes [1] ethylene-vinyl alcohol copolymer (A) (hereinafter sometimes abbreviated as "EVOH (A)") and an additive (B), and the additive (B) is generally described below. Additive (B1) represented by the formula (1) (hereinafter sometimes abbreviated as "additive (B1)") or additive (B2) represented by the following general formula (2) (hereinafter "additive (B2)" ) ”), And the content of the additive (B) is 0.01 to 20% by mass, EVOH resin composition.
[In the formula, R ¹ is a group independently selected from the group consisting of a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, and a hydroxyalkoxy group having 1 to 3 carbon atoms, and R ² is a group. It is a group independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and an alkoxy group having 1 to 3 carbon atoms. ]
[In the formula, R ³ and R ⁴ are alkyl groups having 1 to 20 carbon atoms each having one or more independent hydroxyl groups. ];
[2] The EVOH resin composition of [1], wherein the additive (B) has a melting point of 100 ° C. or higher and 200 ° C. or lower.
[3] The EVOH resin composition of [1] or [2], wherein the additive (B2) is metaxylenebis-12-hydroxystearic acid amide;
[4] The EVOH resin composition according to any one of [1] to [3], wherein the ethylene unit content of EVOH (A) is 20 to 60 mol%;
[5] A molded product made of the EVOH resin composition according to any one of [1] to [4];
[6] A multilayer structure containing at least one layer composed of the EVOH resin composition according to any one of [1] to [4];
Is achieved by providing.

According to the present invention, an EVOH resin composition that does not cause bleed-out, suppresses a decrease in tensile elastic modulus and yield strength, and has improved resin fluidity, and a molded product and a multilayer structure using the same. Can be provided.

It is the evaluation result of the rheological property in the molten state about the molten blend products obtained in Comparative Example 1, Example 2 and Example 4. It is a measurement result of dynamic viscoelasticity about the sample film obtained in Comparative Example 1, Example 1 and Example 2. It is the measurement result of the dynamic viscoelasticity about the sample film obtained in Comparative Example 1, Example 3 and Example 4. It is the measurement result of the free volume about the sample film obtained in Comparative Example 1 and Examples 1 to 4.

The EVOH resin composition of the present invention contains EVOH (A) and an additive (B), and the additive (B) is an additive (B1) or an additive (B2) and contains the additive (B). The rate is 0.01 to 20% by mass.

(EVOH (A))
Since the resin composition of the present invention contains EVOH (A), it exhibits good gas barrier properties. EVOH (A) can usually be obtained by saponifying an ethylene-vinyl ester copolymer. The ethylene-vinyl ester copolymer can be produced and saponified by a known method. Vinyl acetate is a typical vinyl ester, but other fatty acid vinyls such as vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate and vinyl versatic acid. It may be an ester.

The ethylene unit content of EVOH (A) is preferably 20 mol% or more, more preferably 25 mol% or more, still more preferably 33 mol% or more. The ethylene unit content of the EVOH (A) is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less. When the ethylene unit content is 20 mol% or more, the melt moldability tends to be good. On the other hand, when the ethylene unit content is 60 mol% or less, the barrier property tends to be enhanced. The ethylene unit content of EVOH (A) can be determined by a nuclear magnetic resonance (NMR) method.

The degree of saponification of the vinyl ester component of EVOH (A) is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 99 mol% or more. By setting the degree of saponification to 90 mol% or more, the gas barrier property of the molded product can be enhanced. Further, the degree of saponification of EVOH (A) may be 100 mol% or less or 99.99 mol% or less. The degree of saponification of EVOH (A) can be calculated by performing ¹ H-NMR measurement and measuring the peak area of hydrogen atoms contained in the vinyl ester structure and the peak area of hydrogen atoms contained in the vinyl alcohol structure.

Further, EVOH (A) may have a unit derived from a monomer other than ethylene and vinyl ester and a saponified product thereof, as long as the object of the present invention is not impaired. When EVOH (A) has the other monomer unit, the content of the other monomer unit with respect to all the structural units of EVOH (A) is preferably 30 mol% or less, more preferably 20 mol% or less. It is more preferably 10 mol% or less, and particularly preferably 5 mol% or less. When EVOH (A) has a unit derived from the other monomer, the lower limit thereof may be 0.05 mol% or 0.10 mol%. Examples of the other monomer include alkens such as propylene, butylene, penten, and hexene; 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-. Diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diasiloxy-2- Methyl-1-butene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diasiloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6- Alken having an ester group such as asyloxy-1-hexene, 5,6-diasiloxy-1-hexene, 1,3-diacetoxy-2-methylenepropane or a saponified product thereof; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, etc. Unsaturated acid or its anhydride, salt, mono or dialkyl ester, etc .; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefins such as vinyl sulfonic acid, allyl sulfonic acid and metaallyl sulfonic acid. Sulphonic acid or a salt thereof; vinylsilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxy-ethoxy) silane, γ-methacryloxypropylmethoxysilane; alkyl vinyl ethers, vinyl ketone, N-vinylpyrrolidone, vinyl chloride , Vinylidene chloride and the like.

The EVOH (A) may be EVOH (A) post-denatured by a method such as urethanization, acetalization, cyanoethylation, or oxyalkyleneization.

The melt flow rate (MFR) at 190 ° C. and a load of 2160 g, measured in accordance with JIS K 7210: 2014 of EVOH (A), is preferably 5 g / 10 min or more, and more preferably 10 g / 10 min or more. On the other hand, the MFR of EVOH (A) is preferably 100 g / 10 min or less, and more preferably 40 g / 10 min or less. If there is MFR in the above range, the melt moldability tends to be excellent.

One type of EVOH (A) may be used alone, or two or more types may be mixed and used.

(Additive (B))
By having the additive (B), the EVOH resin composition of the present invention can improve the fluidity of the resin composition while suppressing the decrease in tensile elastic modulus and yield strength. Further, by using the additive (B), it is possible to prevent the additive (B) from bleeding out from the resin composition.

The additive (B) is an additive (B1) or an additive (B2). The additive (B1) is a compound represented by the following general formula (1).

R ¹ in the general formula (1) independently has a hydroxyl group (-OH), a hydroxyalkyl group having 1 to 3 carbon atoms (-C _n H _2n OH: n = 1 to 3), and 1 carbon number. It is a group selected from the group consisting of hydroxyalkoxy groups of ~ 3 (-OC _n H _2n OH: n = 1-3), and R ² is independently a hydrogen atom (-H) and 1 to 1 carbon atoms, respectively. Selected from the group consisting of 3 alkyl groups (-C _n H _{2n + 1} : n = 1-3) and alkoxy groups with 1-3 carbon atoms (-OC _n H _{2n + 1} : n = 1-3). It is a base.

Among them, R ¹ is a group selected from a hydroxyl group (-OH) and a hydroxyalkoxy group having 1 to 3 carbon atoms (-OC _n H _2n OH: n = 1 to 3), and R ² is a hydrogen atom. It is preferably (−H).

The additive (B2) is a compound represented by the following general formula (2).

R ³ and R ⁴ in the general formula (2) are alkyl groups having 1 to 20 carbon atoms each having one or more independent hydroxyl groups. The number of hydroxyl groups is preferably 1 to 8, more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 1.

R ³ and R ⁴ are preferably alkyl groups having 10 to 20 carbon atoms having one or more hydroxyl groups, and more preferably alkyl groups having 12 to 20 carbon atoms having one or more hydroxyl groups.

Among them, it is preferable that the additive (B2) is metaxylenebis-12-hydroxystearic acid amide because the yield strength and tensile elastic modulus of the EVOH resin composition of the present invention can be improved and the fluidity can be improved.

From the viewpoint of suppressing the bleed-out of the additive (B), the melting point of the additive (B) is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. The melting point of the additive (B) is preferably 200 ° C. or lower, more preferably 170 ° C. or lower, from the viewpoint of improving the fluidity of the EVOH resin composition of the present invention. The melting point of the additive (B) can be measured according to JIS K0064: 1992.

The content of the additive (B) in the resin composition of the present invention is 0.01 to 20% by mass. If the content of the additive (B) is less than 0.01% by mass, the fluidity is not sufficiently improved. Further, when the content of the additive (B) is more than 20% by mass, the gas barrier property of the resin composition tends to decrease and the tensile elongation at break tends to decrease remarkably. From the viewpoint of sufficiently improving the fluidity, the content of the additive (B) is preferably 3% by mass or more, more preferably 7% by mass or more. Further, from the viewpoint of maintaining good gas barrier properties and suppressing a decrease in tensile elongation at break, the content of the additive (B) is preferably 17% by mass or less, more preferably 12% by mass or less.

The MFR at 190 ° C. and a load of 2160 g, measured according to JIS K 7210: 2014 of the resin composition of the present invention, is preferably 5 g / 10 min or more, and more preferably 10 g / 10 min or more. When the MFR at 190 ° C. and a load of 2160 g is 10 g / 10 min or more, the fluidity tends to be good, and the appearance of the obtained molded product tends to be good. Further, the MFR at 190 ° C. and a load of 2160 g, measured in accordance with JIS K 7210: 2014 of the resin composition of the present invention, may be 50 g / 10 min or less, 40 g / 10 min or less, or 30 g. It may be / 10 min or less. By containing the additive (B), the resin composition of the present invention has improved MFR of the resin composition and good fluidity as compared with the MFR of EVOH (A).

(Other ingredients)
The resin composition of the present invention is, for example, a carboxylic acid compound, a phosphoric acid compound, a boron compound, a metal salt, a stabilizer, an antioxidant, an ultraviolet absorber, and an antistatic agent as long as the effect of the present invention is not impaired. , Lubricants, colorants, fillers, desiccants, and other components such as reinforcing agents such as various fibers may be contained.

When the resin composition of the present invention contains a carboxylic acid compound, it tends to prevent coloring during melt molding. The carboxylic acid contained in the resin composition of the present invention may be a monocarboxylic acid or a polyvalent carboxylic acid, or a combination thereof. The carboxylic acid contained in the resin composition of the present invention may be an ion, and the carboxylic acid ion may form a salt with a metal ion. The content of carboxylic acid and carboxylic acid ion is preferably 1 to 400 ppm.

When the resin composition of the present invention contains a phosphoric acid compound, it tends to prevent coloring during melt molding. The phosphoric acid compound contained in the resin composition of the present invention is not particularly limited, and various acids such as phosphoric acid and phosphorous acid and salts thereof can be used. The phosphate may be contained in any form of a first phosphate, a second phosphate, or a third phosphate, but the first phosphate is preferable. The cation species is also not particularly limited, but an alkali metal salt is preferable. Of these, sodium dihydrogen phosphate and potassium dihydrogen phosphate are preferable. When the resin composition of the present invention contains a phosphoric acid compound, the content of the phosphoric acid compound is preferably 1 to 500 ppm in terms of phosphoric acid root. When the content of the phosphoric acid compound is 1 ppm or more, the color resistance during melt molding tends to be good. On the other hand, when the content of the phosphoric acid compound is 500 ppm or less, the melt moldability tends to be good.

When the resin composition of the present invention contains a boron compound, it tends to be able to suppress torque fluctuations during heating and melting. The boron compound contained in the resin composition of the present invention is not particularly limited, and examples thereof include boric acids, borate esters, borates, and boron hydrides. Specifically, examples of boric acids include orthoboric acid, metaboric acid, tetraboric acid and the like, examples of boric acid esters include triethyl borate and trimethyl borate, and examples of borate salts include the above-mentioned various boric acids. Examples thereof include alkali metal salts of acids, alkaline earth metal salts, and boric acid. Among these compounds, orthoboric acid (hereinafter, may be simply referred to as boric acid) is preferable. When the resin composition of the present invention contains a boron compound, the content of the boron compound is preferably 20 to 2000 ppm in terms of boron element. When the content of the boron compound is 20 ppm or more, the torque fluctuation at the time of heating and melting tends to be suppressed. On the other hand, when the content of the boron compound is 2000 ppm or less, the moldability tends to be kept good.

When the resin composition of the present invention contains an alkali metal salt, the interlayer adhesiveness between the layer made of the resin composition of the present invention and another resin layer is improved in a multilayer structure having a layer made of the resin composition of the present invention. It tends to be good. The cationic species of the alkali metal salt is not particularly limited, but a sodium salt or a potassium salt is preferable. The anion species of the alkali metal salt is also not particularly limited. It can be added as a carboxylate, a carbonate, a hydrogen carbonate, a phosphate, a hydrogen phosphate, a borate, a hydroxide, or the like. When the resin composition of the present invention contains an alkali metal salt, the content of the alkali metal salt is preferably 10 to 500 ppm in terms of metal element. When the content of the alkali metal salt is 10 ppm or more, the interlayer adhesiveness tends to be good. On the other hand, when the content of the alkali metal salt is 500 ppm or less, the melt stability tends to be excellent.

When the resin composition of the present invention contains an alkaline earth metal salt, there is a tendency that deterioration can be suppressed and generation of deteriorated substances such as gel can be suppressed when the molded product is repeatedly melt-molded. The cationic species of the alkaline earth metal salt is not particularly limited, but a magnesium salt or a calcium salt is preferable. The anionic species of the alkaline earth metal salt is also not particularly limited. It can be added as a carboxylate, a carbonate, a hydrogen carbonate, a phosphate, a hydrogen phosphate, a borate, a hydroxide, or the like. When the resin composition of the present invention contains an alkaline earth metal salt, the content of the alkaline earth metal salt is preferably 10 to 500 ppm.

Stabilizers for improving melt stability, etc. include hydrotalcite compounds, hindered phenolic compounds, hindered amine-based thermal stabilizers, and metal salts of higher aliphatic carboxylic acids (for example, calcium stearate, magnesium stearate, etc.). When the resin composition of the present invention contains a stabilizer, the content thereof may be 0.001 to 1% by mass.

Antioxidants include 2,5-di-t-butyl-hydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis- (6-t-butylphenol), 2,2. '-Methylene-bis- (4-methyl-6-t-butylphenol), octadecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-Butylphenol) and the like.

Examples of the ultraviolet absorber include ethylene-2-cyano-3,3'-diphenylacrylate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, and 2- (2'-hydroxy-3'-t-). Butyl-5'-methylphenyl) 5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone and the like can be mentioned.

When the resin composition of the present invention contains the other components, the ratio of EVOH (A) and the additive (B) in the resin composition of the present invention is preferably 95% by mass or more, more preferably 97% by mass or more. 99% by mass or more is more preferable.

The method for producing the resin composition of the present invention is not particularly limited, and for example, it can be produced by mixing or kneading EVOH (A) and the additive (B) under melting conditions. Mixing or kneading under melting conditions can be performed using a known mixing or kneading device such as a kneader ruder, extruder, mixing roll, Banbury mixer or the like. The temperature at the time of mixing or kneading may be appropriately adjusted according to the melting point of EVOH (A) to be used, but usually a temperature within the temperature range of 160 ° C. or higher and 300 ° C. or lower may be adopted.

Further, the melting point of the resin composition of the present invention is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, because melt molding is facilitated. The melting point of the resin composition of the present invention is preferably 220 ° C. or lower, more preferably 190 ° C. or lower.

<Molded body>
Since the resin composition of the present invention has thermoplasticity, the molded product made of the resin composition of the present invention uses a normal molding processing method or molding processing apparatus used for a general thermoplastic polymer. Can be molded. As the molding method, for example, any method such as injection molding, extrusion molding, press molding, blow molding, calender molding, vacuum forming, compression molding molding and the like can be adopted. The shape of the molded product containing the resin composition produced by such a method includes a mold, a pipe, a sheet, a film, a disk, a ring, a bag, a bottle, a string, a fibrous, and the like. A wide variety of shapes are included, preferably in the form of a film. The molded product may substantially contain only the resin composition.

The molded product of the present invention can be used, for example, as a single-layer film-like structure. Suitable uses of the molded product include food and drink packaging materials, container packing materials, medical infusion bag materials, gasoline tank materials, tire tube materials, cosmetic packaging materials, pharmaceutical packaging materials, toothpaste packaging materials, and the like. And cushioning material for shoes.

<Multi-layer structure>
The multilayer structure of the present invention has a layer containing the resin composition. The layer containing the resin composition may be a layer containing substantially only the resin composition. By having the layer containing the resin composition, the multilayer structure of the present invention can improve moisture resistance, mechanical properties and the like. The number of layers constituting the multilayer structure is not particularly limited as long as it is 2 or more, but for example, 2 or more and 10 or less are preferable, and 3 or more and 5 or less are more preferable.

The multilayer structure of the present invention has, for example, at least one layer containing the resin composition (the resin composition layer) and at least one layer composed of other materials. As the other material, a suitable material can be appropriately selected according to the required characteristics, the planned application, etc. For example, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-propylene. Polypolymers, polyolefins such as polypropylene; thermoplastic polymers such as ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, polystyrenes, vinyl chloride resins, vinylidene chloride resins; ionomers and the like.

In the multilayer structure of the present invention, an adhesive layer or an adhesive may be interposed between the resin composition layer and a layer composed of other materials. By interposing an adhesive layer or an adhesive, the two layers on both sides thereof can be firmly joined and integrated. Examples of the adhesive layer and the adhesive include an acid anhydride modified product of a diene polymer, an acid anhydride modified product of a polyolefin, and a mixture of a polymer polyol and a polyisocyanate compound. However, when the layer composed of other materials is a polyolefin layer, it is not necessary to interpose the adhesive layer or the adhesive because the interlayer adhesiveness is excellent without interposing the adhesive layer or the adhesive. It should be noted that known methods such as co-extrusion, co-injection, and extrusion coating can also be used to form the multilayer structure of the multilayer structure.

Since the multilayer structure of the present invention has excellent gas barrier properties and mechanical properties in a well-balanced manner, it can be used as daily necessities, packaging materials, mechanical parts, etc. that require these properties. Examples of applications in which the features of the multilayer structure are particularly effectively exhibited are food and drink packaging materials, container packing materials, medical infusion bag materials, gasoline tank materials, tire tube materials, and cosmetic packaging materials. , Pharmaceutical packaging material, toothpaste packaging material, shoe cushioning material, container, bag-in-box inner bag material, organic liquid storage tank material, organic liquid transportation pipe material, hot water pipe material for heating (hot water for floor heating) (Pipe material, etc.), resin wallpaper, etc.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto.

[Example 1]
Ethylene-vinyl alcohol copolymer (A) with an ethylene unit content of 44 mol%, saponification degree of 99.9 mol%, MFR 12 g / 10 min EVOH at 190 ° C. in 95 parts by mass, Osaka Gas Chemicals as an additive (B1) After dry blending 5 parts of Ogsol MF-11 (B1-1) manufactured by Ogsol Co., Ltd. and kneading at 200 ° C. at 20 rpm for 3 minutes using a lab plast mill (“50M” biaxially different direction manufactured by Toyo Seiki Seisakusho Co., Ltd.). , Kneaded at 50 rpm for 7 minutes and cut with scissors to obtain a 5 mm square molten blend product.

[Melt flow rate (MFR)]
For the molten blend product obtained above, a sample outflow rate (g / 10 minutes) was used under the conditions of a temperature of 190 ° C. and a load of 2160 g in accordance with JIS K 7210: 2014 using a melt indexer (L244 manufactured by Takara Kogyo Co., Ltd.). Was measured to determine the MFR.

[Melting point (Tm) of resin composition]
The molten blend product obtained above is heated from 30 ° C. to 210 ° C. at a rate of 10 ° C./min, cooled to 50 ° C. at 10 ° C./min, and again at 50 ° C. according to JIS K7121: 2012. Measurements were carried out at a heating rate of 10 ° C./min from to 210 ° C. (Shimadzu Differential Scanning Calorimeter (DSC) "DSC-60A"). The melting peak temperature (Tpm) was determined from the 2nd run chart according to the JIS, and this was used as the melting point of the resin composition.

[Film production]
By placing 3 g of the molten blend product obtained above in a 10 cm × 10 cm aluminum frame and pressurizing it at 200 ° C. at a pressure of 10 MPa using a heat press machine (manufactured by Imoto Seisakusho Co., Ltd., model: MH-10). , A film having a thickness of 300 μm (hereinafter referred to as a sample film) was obtained.

[Yield strength, elongation at break, tensile modulus]
The sample film was cut into a dumbbell shape and used as a test piece. The size of the sample piece was 60 mm in total length, 10 mm in length at the center, 4 mm in width at the center, and 300 μm in thickness. Between chucks by a precision universal testing machine (trade name: Autograph EZ-Test, JIS B 7721: 2009 0.5 class and ISO 750-1 (2004) class 0.5, manufactured by Shimadzu Corporation) A constant-speed tensile test was performed on the test piece under the conditions of a distance of 10 mm and a tensile speed of 20 mm / min, and the yield strength, breaking elongation, and tensile elastic modulus were measured.

[Long period, lamella thickness, amorphous thickness]
The sample film was measured for long period, lamella thickness, and amorphous thickness using a small-angle X-ray scattering device (BL40B2 of a large radiation facility (Spring-8)) under the following conditions.
Standard sample: Silver behenate Wavelength: 1 Å
Exposure time: 5s

[Bleed out]
The sample film was stored under the condition of 40 ° C./100% RH for 7 days, bleed-out was visually confirmed, and the determination was made as follows.
A: No bleed out has occurred.
B: Bleedout occurred.
The obtained measurement results are shown in Table 1.

(Examples 2 to 4, Comparative Example 1)
As shown in Table 1, a melt-blended product (resin composition) and a sample film were prepared and evaluated in the same manner as in Example 1 except that the amount and type of the additive added were changed. The results are shown in Table 1. In the table, the additive (B2-1) represents metaxylenebis-12-hydroxystearic acid amide.

The melt-blended products of Examples 2 and 4 and Comparative Example 1 were measured for viscoelasticity, dynamic viscoelasticity, and free volume according to the following methods, and the evaluation results are shown in FIGS. 1 to 4.
[Viscoelasticity]
The melt viscosity of the obtained melt-blended product in the low shear region was measured using a rotary rheometer (MCR302 manufactured by AntonioPaar) under the following conditions.
Atmosphere: Nitrogen measurement temperature: 200 ° C
Strain: 1.0%
[Dynamic viscoelasticity]
The dynamic viscosity of the obtained sample film was measured under the following conditions using a dynamic viscoelasticity measuring device (RHEOGEL-E4000 manufactured by UBM Co., Ltd.).
Between chucks: 2 cm
Frequency: 8Hz
Heating rate: 3 ° C / min
[Free volume]
The free volume of the obtained sample film was measured under the following conditions using a positron annihilation lifetime measuring device.
Temperature: 23 ° C, vacuum positron source: ²² Na
Analysis software: PALS Fits

From the comparison between the examples and the comparative examples, it is found that by using a specific additive, bleed-out does not occur, the decrease in the physical properties of the tensile elastic modulus and the yield strength is suppressed, and the fluidity is effectively improved. Understand. From the crystallization rate, long-period, and low-frequency region viscous measurements, the composition containing the additive (B1) has the characteristic of delaying the crystallization process but maintaining the hydrogen-bonded natework structure. The composition containing the additive (B2) promotes crystallization, but is considered to have the characteristic of breaking hydrogen bonds in the molten state.

The application is not limited to the use of the present invention, and can be applied to a wide range of fields such as food, pharmaceutical, industrial chemicals, and pesticides.

Claims (6)

It contains an ethylene-vinyl alcohol copolymer (A) and an additive (B), and the additive (B) is an additive (B1) represented by the following general formula (1) or an additive represented by the following general formula (2). An ethylene-vinyl alcohol copolymer resin composition which is an agent (B2) and has an additive (B) content of 0.01 to 20% by mass.
[In the formula, R ¹ is a group independently selected from the group consisting of a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, and a hydroxyalkoxy group having 1 to 3 carbon atoms, and R ² is a group. It is a group independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and an alkoxy group having 1 to 3 carbon atoms. ]
[In the formula, R ³ and R ⁴ are alkyl groups having 1 to 20 carbon atoms each having one or more independent hydroxyl groups. ] The ethylene-vinyl alcohol copolymer resin composition according to claim 1, wherein the additive (B) has a melting point of 100 ° C. or higher and 200 ° C. or lower. The ethylene-vinyl alcohol copolymer resin composition according to claim 1 or 2, wherein the additive (B2) is metaxylenebis-12-hydroxystearic acid amide. The ethylene-vinyl alcohol copolymer resin composition according to any one of claims 1 to 3, wherein the ethylene-vinyl alcohol copolymer (A) has an ethylene unit content of 20 to 60 mol%. A molded product made of the ethylene-vinyl alcohol copolymer resin composition according to any one of claims 1 to 4. A multilayer structure including at least one layer composed of the ethylene-vinyl alcohol copolymer resin composition according to any one of claims 1 to 4.