JP3449747B2 - Resin composition and multilayer structure - Google Patents

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has improved gas barrier properties, improved drop impact resistance, flex resistance, air bag prevention, skin pack packaging suitability, shrink film suitability, and other flexibility and transparency. The present invention relates to a resin composition and a multilayer structure having the composition layer.

[0002]

2. Description of the Related Art Saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVOH) is a thermoplastic resin having excellent transparency, gas barrier property, oil resistance, and aroma retention compared to other resins. It is used for various gas barrier films and gas barrier layers of gas barrier containers. But E
Multi-layer films and multi-layer containers using VOH as a gas barrier layer often have problems due to the high rigidity of EVOH. For example, a multi-layer film or container filled with contents may be easily broken or broken when dropped, a pin hole may occur in the multi-layer film filled with contents due to bending or vibration during transportation, The problems include occurrence of wrinkles during skin pack packaging, insufficient stretchability as a shrink wrapping film, and insufficient shrinkability.

Therefore, there has been considered a method of blending EVOH with another thermoplastic resin to improve these drawbacks. For example, a method of adding a plasticizer such as butylene glycol or dioctyl phthalate to EVOH, an ethylene-vinyl acetate copolymer, an ethylene-carboxylic acid vinyl ester copolymer, an ethylene-acrylic acid ester copolymer,
A method of blending an α, β-unsaturated carboxylic acid or an ethylene-carboxylic acid vinyl ester copolymer modified with the carboxylic acid anhydride, or an ethylene-acrylic acid ester copolymer is used. However, the former method has the drawback of bleeding the plasticizer. The latter method has a great effect of improving flexibility and impact resistance, but impairs transparency, which is a characteristic of EVOH.

Further, by blending EVOH with a partially saponified ethylene-vinyl acetate copolymer (hereinafter referred to as partially saponified EVA), and by using the blend, interlayer adhesion between the EVOH and the polyolefin is imparted. Japanese Patent Publication No. S51-4851 and Japanese Patent Application Laid-Open No. S60-161447 describe that a low temperature sealing property is imparted. When a molded article such as a film is produced according to the method described in these prior arts. However, there are problems such as poor flexibility, poor thermal stability, severe neck-in and poor moldability, and the fact that streaks and satin patterns are on the film surface has not been put to practical use. is there.

For this reason, the EVOH has a good balance of drop impact resistance, bending resistance, air bag prevention, flexibility such as skin pack suitability, shrink film suitability, etc., gas barrier property and transparency, and a resin composition or a multilayer structure. It was the present condition that the body was not obtained.

[0006]

As described above, EVOH has various excellent properties, but on the other hand, the multi-layer film container filled with the contents is ruptured by bag dropping and pinholes are generated due to bending and vibration during transportation. Problems often arise due to equal stiffness. The object of the present invention is to improve the above-mentioned problems by imparting flexibility to EVOH,
It is to provide a resin composition having good gas barrier properties.

[0007]

The above objects are (A) 60 to 95% by weight of an ethylene-vinyl acetate copolymer saponified product having (A) an ethylene content of 20 to 60 mol% and a saponification degree of a vinyl acetate component of 90% or more. , (B) 4 to 40% by weight of an ethylene polymer having a density of 0.92 g / cm ³ or less, and (C) a hydrophobic plasticizer having a solubility parameter (SP) of 8 to 12 of 0.1 to 1.
It is achieved by providing a resin composition consisting of 0% by weight, and a multilayer structure having the resin composition layer and a thermoplastic resin layer adjacent thereto.

According to the present invention, there is no bleed-out of the plasticizer, the gas barrier after molding is increased with the lapse of time, and finally, a multilayer structure having substantially the same level as that of the plasticizer-free product is obtained. To be

The present invention will be described in more detail below. EVOH (A) used in the present invention has an ethylene content of 20-
60 mol%, saponification degree of vinyl acetate component is 90% or more,
It is preferably at least 95%. If the ethylene content is less than 20 mol%, the molding temperature will be close to the decomposition temperature and molding will be difficult. If the ethylene content exceeds 60 mol%, the gas barrier property becomes unsatisfactory, which is not preferable. Further, EVOH having a degree of saponification of the vinyl acetate component of less than 90% is not preferable because it has a poor gas barrier property.

The EVOH referred to in the present invention may be modified with a copolymerization monomer in the range of 5 mol% or less. Examples of the modifying monomer include propylene, 1-butene and 1-butene.
Hexene, 4-methyl-1-pentene, acrylic acid ester, methacrylic acid ester, maleic acid, fumaric acid,
Itaconic acid, higher fatty acid, vinyl ester, alkyl vinyl ether, N- (2-dimethylaminoethyl) methacrylamide or its quaternary compound, N-vinylimidazole, or its quaternary compound, N-vinylpyrrolidone, N-N- Examples thereof include butoxymethyl acrylamide, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane and the like.

The ethylene polymer (B) used in the present invention has a density of 0.92 g / cm ³ or less, preferably 0.
It is 90 g / cm ³ or less. When the density of the ethylene-based polymer is 0.92 g / cm ³ or more, the degree of crystallinity is high, and there is a problem in the desired flexibility.

The ethylene-based polymer contains ethylene as a main component and is one of α-olefins having 3 or more carbon atoms, preferably 3 to 10 carbon atoms, such as propylene, butene, isobutene, 4-methylpentene, hexene and octene. Alternatively, two or more kinds or butadiene and a chrome-based catalyst or a Ziegler catalyst at a pressure of 7 to 45 kg / cm ² and a temperature of 75 to 100 ° C. with a solution method liquid phase method, a slurry method liquid phase method, a fluidized bed gas phase method. , A copolymer obtained by polymerization using a stirred bed gas phase method or the like, or ethylene as a main component, vinyl acetate, acrylate ester, methacrylic acid ester, etc., in the same manner as ordinary low density polyethylene polymerization. ~ 3000
It is obtained by polymerization using a radical catalyst at a pressure of kg / cm ² and a temperature of 120 to 250 ° C. using a fluidized bed gas phase method, a stirred bed gas phase method or the like.

It is important for the SP value of the hydrophobic plasticizer (C) used in the present invention to satisfy 8 to 12, and preferably between the SP value of the adjacent thermoplastic resin and the SP value of EVOH. SP value of, more preferably SP that is a little closer to the thermoplastic resin
It is a value, and a preferable range is 8.5 to 11.5. SP
When the value is less than 8, the hydrophobic plasticizer not only migrates into the thermoplastic resin layer but bleeds out to the surface of the thermoplastic resin layer because it approaches the SP value of the thermoplastic resin.
Further, when the SP value exceeds 12, the hydrophobic plasticizer remains in the resin composition layer, resulting in deterioration of the gas barrier. Examples of the hydrophobic plasticity include aromatic esters, aliphatic esters, phosphoric acid esters, and epoxy compounds thereof.

As the aromatic ester, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate,
Di2 ethylhexyl phthalate, dicyclohexyl phthalate, butyl lauryl phthalate, diisooctyl phthalate, butyl coconut alkyl phthalate, ditridecyl phthalate, dilauryl phthalate, diisodecyl phthalate, butyl benzyl phthalate, octyl decanoyl phthalate, dimethyl glycol phthalate, ethyl phthalyl Ethylene glycolate, methylphthalyl ethylene glycolate, butylphthalyl butylene glycolate, dinonyl phthalate, diheptyl phthalate, octyl decyl phthalate, ditridecyl phthalate, dicapryl phthalate, di3,5,5 trimethylhexyl phthalate, isooctyl isolate Decyl phthalate, dimethoxyethyl phthalate, dibutoxycidiethyl phthalate, bis ( Ethylene glycol monomethyl ether) phthalate, and benzo phenol.

Examples of the aliphatic ester include monoesters and diesters of polyhydric alcohols (dihydric, trihydric or higher polyhydric alcohols) and higher fatty acids (higher fatty acids having 8 or more carbon atoms, preferably 8 to 30 carbon atoms). , Or higher ester such as glycerin monostearate, glycerin distearate, glycerin tristearate,
And polypropylene adipate, diisodecyl adipate, di2-methylhexyl adipate,
Dicapryl adipate, diisooctyl adipate, octyldecyl adipate, isooctyl isodecyl adipate, dibutyl fumarate, dioctyl fumarate,
Examples thereof include triethyl citrate, acetyl triethyl citrate, tributyl citrate, acetyl tributyl citrate, acetyl tri-2-ethylhexyl citrate and the like. Further, as the phosphoric acid ester, tricresyl phosphate, phenyl dicrezif phosphate, xylenyl dicresyl phosphate, cresyl dixylenyl phosphate, triphenyl phosphate, tributyl phosphate, trichloroethyl phosphate, trioctyl. Examples thereof include phosphates, tributyl phosphates, trichloroethyl phosphates, trioctyl phosphates, triethyl phosphates, arylalkyl phosphates, diphenylmonoorthoxenyl phosphates and the like.

Examples of the epoxy compound include epoxy monoester, butyl epoxy stearate, octyl epoxy stearate, epoxy butyl oleate, epoxidized butyl oleate, epoxidized soybean oil, epoxidized linseed oil, epoxidized alkylfruyl oil. , Epoxidized alkyl oil alcohol ester and the like. Among them, glycerin monostearate, glycerin tristearate, benzophenol, butylbenzyl phthalate, epoxidized soybean oil, epoxidized linseed oil,
Dinetylhexyl adipate, diisooctyl adipate, dibutyl phthalate, diethyl phthalate, di2 ethylhexyl phthalate, methylphthalyl ethylene glycolate and the like are preferably used. As the compound (B), one type or two or more types of the above-mentioned compounds are used.

Regarding the blending ratio of the components (A), (B) and (C), EVOH (A) is 60 to 95% by weight, preferably 70 to 95% by weight, and the ethylene polymer (B) is used. ) Is 4 to 40% by weight, preferably 4 to 25% by weight, and the hydrophobic plasticizer (C) is 0.1 to 10% by weight, preferably 0.1 to 5% by weight.

The greatest feature of the present invention is that the disadvantage of bleeding out of the plasticizer is used in reverse. Since the flexibility of the present invention is not sufficient just by blending the EVOH with the ethylene polymer, a plasticizer is added to give more flexibility. It increases with the passage of, and finally shows almost the same level as that of the plasticizer-free product. The resin composition of the present invention is often used in multiple layers.

For example, when the resin composition layer of the present invention is used as an intermediate layer and a thermoplastic resin layer is provided in a layer adjacent thereto, the present inventors have found that the plasticizer of the resin composition layer is Naturally, it remains in the resin composition layer, but with the passage of time, it is thought that it may move in the direction of the resin close to the SP value (dissolution parameter) which is an index of solubility, and attention was paid to this SP value. Therefore, a thorough study was conducted to prevent the bleed out of the plasticizer.

First, the SP value of EVOH of the resin composition layer,
As expected when a plasticizer having an SP value smaller than the SP value of the thermoplastic resin adjacent to the resin composition layer was used, the plasticizer passed through the thermoplastic resin layer and bleeded out to the surface. Next, the present inventors examined a plasticizer having an SP value close to EVOH. As a result, the plasticizer did not bleed out on the surface of the thermoplastic resin layer, and it was confirmed from the measurement of gas barrier properties that the plasticizer remained in the resin composition layer. Furthermore, there was no problem with respect to the film surface, transparency, and moldability, and the results were tentatively achieved. However, the inventors of the present invention made use of the SP value characteristics to keep the plasticizer in the bleed hood from the resin composition layer and We made a diligent study, thinking that it could be captured by the thermoplastic resin layer that As a result, the SP value of the plasticizer is slightly closer to the SP value of the thermoplastic resin than the intermediate value of the SP values of the EVOH and the adjacent thermoplastic resin,
Moreover, when the one having a SP value larger than that of the thermoplastic resin, for example, preferably 0.3 or more, more preferably 0.5 or more, is used, the bleed-out of the plasticizer from the surface of the thermoplastic resin (outer layer) occurs. Moreover, since the gas barrier after molding increased with the passage of time and finally reached almost the same level as the plasticizer-free product, the plasticizer migrated from the resin composition layer to the adjacent thermoplastic resin layer. Then, it was confirmed that they were caught in that layer. Furthermore, there were no problems in terms of film surface, transparency and moldability, and the present invention was completed.

According to the present invention, since the resin composition layer contains a plasticizer during molding and processing, it has more flexibility, but after processing, the plasticizer escapes from the resin composition layer. Then, the gas barrier property gradually increased, and finally, it reached the level of the performance of the plasticizer-free product.

In order to blend the EVOH with the ethylene polymer alone to impart flexibility, it is necessary to increase the ethylene polymer, resulting in deterioration of the barrier property. On the other hand, EV
If only OH is blended with a hydrophobic plasticizer, after the molding, the hydrophobic plasticizer may move to the thermoplastic resin layer, resulting in a significant loss of flexibility and a situation in which the polymer cannot be used. A blend of hydrophobic plasticizers is essential.

Further, in the present invention, JP-A-60-19 is used.
A salt or oxide containing at least one element selected from Group I, Group II and Group III of the periodic law disclosed in No. 9040 can be blended, and other conventional additives can be blended. You can also do it. Examples of such additives include antioxidants, UV absorbers, plasticizers,
Examples thereof include antistatic agents, lubricants, colorants, fillers, and other polymer compounds, and these can be blended within a range that does not impair the effects of the present invention.
The following are specific examples of the additive.

Antioxidants: 2,5-di-t-butylhydroquinone, 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.

UV absorber: ethylene-2-cyano-
3,3-diphenyl acrylate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2
-(2'hydroxy-3'-t-butyl-5'-methylphenyl) 5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2-hydroxy-
Octoxybenzophenone etc.

Antistatic agent: pentaerythritol monostearate, sorbitan monopalmitate, sulfated oleins, polyethylene oxide, carbowax and the like. Lubricants: ethylene bis stearamide, butyl stearate, etc. Coloring agents: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, red iron oxide, titanium oxide and the like.

Examples of means for blending the respective components for obtaining the composition of the present invention include a ribbon blender, a high speed mixer co-kneader, a mixing roll, an extruder and an intensive mixer.

The resin composition of the present invention is a well-known melt extrusion molding machine, compression molding machine, transfer molding machine, injection molding machine,
Using blow molding machine, thermoforming machine, rotation molding machine, dip molding machine, etc., film, sheet, tube, bottle,
It can be molded into any molded product such as a cup. The extrusion temperature at the time of molding is appropriately selected depending on the type of resin, the molecular weight, the compounding ratio of the composition, the properties of the extruder and the like, but in most cases, it is in the range of 170 to 350 ° C.

The resin composition of the present invention may have any layer constitution of at least two layers having this composition layer and a thermoplastic resin layer adjacent thereto, but preferably the above composition layer is used as an intermediate layer. , And has a layer structure of three or more layers having thermoplastic resin layers adjacent to both side layers thereof.

As layers other than the resin composition layer of the present invention,
Examples thereof include a thermoplastic resin layer (including an adhesive resin layer).
Here, as the thermoplastic resin, high-density, medium-density, or low-density polyethylene, vinyl acetate, acrylate, or polyethylene in which α-olefins such as butene, hexene, and 4-methyl-1-pentene are copolymerized, Ionomer resin, polypropylene homopolymer,
Polypropylene graft-polymerized with ethylene, polypropylene copolymerized with α-olefins such as ethylene, butene, hexene and 4-methyl-1-pentene, modified polypropylene blended with a rubber-based polymer, poly-1-butene, poly-4- It contains methyl-1-pentene or a modified polyolefin obtained by reacting maleic anhydride with the above-mentioned polyolefin.

Alternatively, polyamide resin, polyester resin, polystyrene resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride resin, polyurethane resin, polyvinyl acetate resin, polyacetal resin, polycarbonate resin And so on.

As the adhesive resin, a polyolefin modified with an unsaturated carboxylic acid or its derivative is preferable. The modified polyolefin resin is an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, its ester or its anhydride; methyl acrylate, methyl methacrylate, Ethyl acrylate,
At least one kind selected from the group consisting of propyl acrylate, butyl acrylate, butyl methacrylate, vinyl acetate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate, unsaturated carboxylic acid derivatives such as sodium methacrylate; The polyolefin resin modified by the unsaturated carboxylic acid or its derivative or its blend.
Preferred examples of the polyolefin resin include polyethylene, polypropylene, ethylene-vinyl acetate, and acrylic acid ester copolymer.

As a suitable example of the layer constitution, when the resin composition of the present invention is represented by D, the thermoplastic resin E and the adhesive resin are represented by AD, the following layer constitution is obtained. 3 layers E / D / E 4 layers E / D / AD / E, E / D / AD / D 5 layers E / AD / D / AD / E

Since the multilayer structure having the above-mentioned layer structure contains EVOH having excellent gas barrier properties, it is particularly required for food packaging materials and medical products (pharmaceutical products, pharmaceutical products, which require gas barrier properties).
It is useful as a packaging material such as medical equipment. In particular, a multilayer structure having at least one resin composition (D) layer is preferable because it is excellent in gas barrier properties.

As a multilayer molding method, generally, the number of extruders corresponding to the type of resin layer is used, and the coextrusion molding is carried out in a layered state in which the flows of the resin melted in the extruder are superposed. The method carried out by so-called coextrusion molding is the best. As another method, a multilayer molding method such as extrusion coating or dry lamination can be adopted. Also, a single molded product of the resin composition of the present invention,
Alternatively, a multilayer structure containing the resin composition of the present invention is subjected to stretching such as uniaxial stretching, biaxial stretching, or blow stretching to obtain a molded product having more physical properties such as mechanical properties and gas barrier properties. be able to. Thus, the molded product obtained from the resin composition of the present invention has many properties such as strength physical properties and gas barrier properties because not only the blend composition is uniform and the appearance is beautiful, but also the compatibility is good and uniform. It has excellent features and its industrial significance is great. Hereinafter, the present invention will be described more specifically by way of examples.
The parts mean parts by weight.

[0036]

【Example】

Example 1 Ethylene content was 32 mol%, saponification degree of vinyl acetate component was 99%, MI was 1.0 g / 10 min (190 ° C., 216
(Measured under 0 g load) 70 parts by weight of EVOH with SP value of 12.3 and low density polyethylene 25 with a density of 0.90 g / cm ³
15 parts by weight of a hydrophobic plasticizer dibutyl phthalate having an SP value of 9.5 and a weight of 15 μm, and 4-methyl-1-pentene having a thickness of 30 μm on both sides of the intermediate layer as a copolymerization component, The copolymerization component was contained in an amount of 3.2 mol% and MI was 2.
Linear low density polyethylene SP value of 1 g / 10 min 7.8
5 μm thick maleic acid-modified polyethylene-based adhesive resin (Mitsui Petrochemical A
A laminated film having 85 μm of all layers arranged via a DMER NF500) SP value of 7.7 was obtained by a coextrusion method using three extruders and a three-layer, five-layer multi-layer die head. The composition used for the intermediate layer was previously blended by an extruder (220
Pellets of 30 ° different-direction biaxial extruder (° C.) were used.
A gelbo flex test was performed on the obtained laminated film until generation of pinholes was observed in the laminated film, and the oxygen gas permeation amount was measured under the condition of 20 ° C. and 65% RH every one week after conditioning. As a result, the occurrence of pinholes was not observed until after 8000 round trips of the bending fatigue test, and after 10500 round trips,
It was confirmed that pinholes had already occurred at the time of inspection for the presence of pinholes. No delamination between the layers was observed at all. On the other hand, the amount of oxygen gas permeation decreased with the passage of days and became almost stable in 3 weeks, reaching 1.1c.
The value of c / m ² · day · atm is shown. Table 1 shows almost the same level of haze immediately after film formation (10%) and after 4 weeks (11%).

Comparative Example 1 The same evaluation as in Example 1 was carried out except that the hydrophobic plasticizer was not used among those blended with the intermediate EVOH in Example 1. The measurement results are shown in Table 1. Compared with Example 1, the oxygen gas permeation amount showed a slightly lower value after 2 weeks, but showed the same value after 3 weeks. Also, bending fatigue test (6100 times) and haze (20 immediately after film formation)
%) Was inferior to Example 1.

COMPARATIVE EXAMPLE 2 Maleic anhydride-modified (maleic anhydride content 0.02% by weight) polyethylene 90% by weight, ethylene content 32% by mole, saponification degree of vinyl acetate component 99% EVOH 10% by weight, glycerin 5 parts by weight Example 1 on both sides of a 15 μm thick intermediate layer consisting of (amount per 100 parts by weight of EVOH)
A laminated film having the same polymer and thickness as in Example 1 was obtained under the same extruder and extrusion conditions as in Example 1. The same evaluation as in Example 1 was performed on the obtained laminated film. The measurement results are shown in Table 1. The oxygen gas permeation amount was significantly inferior to that of Example 1. (1.1 cc → 2 after 4 weeks)
560 cc) The bending fatigue test (9800 times) and the haze (9% immediately after film formation) were at the same level.

[0039]

[Table 1]

Example 2 Ethylene content 32 mol%, saponification degree of vinyl acetate component 99%, MI 1.0 g / 10 minutes, SPOH 12.3 parts by weight of EVOH 70 parts by weight, density 0.90 g / cm 3. ^An average thickness of 2 consisting of 25 parts by weight of ³ low-density polyethylene and 5 parts by weight of the hydrophobic plasticizer dimethyl phthalate having an SP value of 10.8.
A 0 μm intermediate layer and a surface layer having an average thickness of 150 μm each consisting of an ethylene-vinyl acetate copolymer SP value of 9.5 with a vinyl acetate content of 8% by weight on both sides of the intermediate layer, and acetic acid between each layer. A maleic anhydride-modified ethylene-vinyl acetate copolymer having a vinyl content of 20% by weight and a maleic anhydride content of 0.5% by weight and having an SP value of 9.6, and having an average thickness of 15 μ, were all disposed through an adhesive resin layer. A tube having an average layer thickness of 350 μ (internal volume of 250 ml) was obtained by a direct blow method using three extruders and a three-layer five-layer die head. As the composition used for the intermediate layer, pellets preliminarily blended by an extruder were used. 15m wide at the center of the body of the obtained tube
Cut with m and loop stay funnel tester 10mm
The repulsive force when compressed was 500 mg.

Comparative Example 3 Example 2 was repeated except that the hydrophobic plasticizer was not used among those blended with the intermediate EVOH in Example 2.
When the same evaluation as above was performed, the repulsive force was 800 mg.

Example 3 Ethylene content 32 mol%, vinyl acetate component saponification degree 99%, MI 1.0 g / 10 minutes, SP value 12.3 EVOH 70 parts by weight, density 0.90 g / cm 3. An intermediate layer (B) having a thickness of 140 μ, which comprises 25 parts by weight of low-density polyethylene ³ and 5 parts by weight of a hydrophobic plasticizer dibutyl phthalate having an SP value of 9.5, and an MI having a thickness of 140 μ on both sides of the nuclear intermediate layer.
(230 ° C.) 0.5 g / 10 min surface layer (A) made of polypropylene resin (A) SP value of 8.0, and a 60 μm-thick maleic acid-modified polypropylene-based adhesive resin (Mitsui Petrochemical Co., Ltd.). ADMER QF-500) layer (C)
3 layers of 1960μ in all layers arranged through SP value 8.0
Coextrusion of the layers was carried out to obtain a sheet. Extrusion molding is A
Has a diameter of 65 mm and an extruder equipped with a single screw of L / D = 22 at a temperature of 200 to 240 ° C., and B has a diameter of 4
0 mm, the extruder equipped with a single screw L / D = 26, the temperature of 170 ~ 210 ℃, C is 40 mm diameter,
L / D = 22 single screw extruder 160
A feedblock die (width 600 mm) was set to 240 ° C. at a temperature of ˜230 ° C. to obtain a sheet having a thickness of 1960 μ. As the composition used for the intermediate layer, pellets preliminarily blended by an extruder were used. Further, a cup having an opening of 7.5 cm and a drawing ratio of 1: 2 was formed by a known thermoforming method. The cup was filled with water, the lid was heat-sealed, and the cup was left standing at 5 ° C. for 3 hours and dropped onto a concrete floor from a height of 2 m three times, but it did not break and showed good drop impact resistance.

Comparative Example 4 The same molding as in Example 3 was carried out except that EVOH was used alone in the intermediate layer in Example 3, and the same drop test was carried out. The cup broke on the first drop.

[0044]

According to the present invention, a resin composition having excellent flexibility can be obtained without deteriorating the gas barrier property. As a result, it is possible to provide a multilayer structure having excellent bending resistance, drop impact resistance, air bag prevention, skin pack suitability, and shrink film suitability.

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Claims (6)

(57) [Claims] 1. A (A) an ethylene content of 20 to 60 mol%, is saponification degree of 90% or more of vinyl acetate component ethylene - vinyl acetate copolymer saponified 60-95 wt%, (B) Density 0. 92 g / cm ³ or less of an ethylene polymer 4 to 40% by weight, (C) a hydrophobic plasticizer having a solubility parameter of 8 to 12
A resin composition comprising 1 to 10% by weight. 2. A multilayer structure having a layer of the resin composition according to claim 1 and a layer of another thermoplastic resin adjacent thereto. 3. The multi-layer structure is a film.
Mounted multi-layer structure. 4. The multilayer structure is a direct blow container.
The multilayer structure according to claim 2, wherein 5. The multilayer structure is a thermoformed container.
The described multilayer structure. 6. A layer and a layer of the resin composition according to claim 1.
A layer of another thermoplastic resin adjacent to it is formed by the coextrusion method.
A method for producing a multilayer structure obtained by remolding.