JP2836938B2 - Resin composition and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention has excellent gas barrier properties, especially under high humidity conditions, and has excellent drop impact resistance, bending resistance, air back prevention, and skin pack packaging suitability. The present invention relates to a resin composition having excellent flexibility and the like, and a laminate including at least one resin composition layer.

B. Conventional technology Ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) is usually obtained by copolymerizing and saponifying ethylene and vinyl acetate, and has gas barrier properties, oil resistance, solvent resistance, and fragrance retention. Because of its excellent properties, it is used for gas barrier layers of various gas barrier films and gas barrier containers. However, multi-layer films, multi-layer containers and the like using EVOH as a gas barrier layer often have problems due to the high rigidity of EVOH. For example, a multilayer film or container filled with contents may break or break when dropped, pinholes may be generated due to bending or vibration during transportation of the multilayer film filled with contents, or
There are problems such as the occurrence of air back in the multilayer tube and the occurrence of wrinkles in the skin pack packaging. Thus, a method has been proposed in which a flexible olefin resin is blended with EVOH to improve these disadvantages. For example, blending ethylene-carboxylic acid vinyl ester copolymer and ethylene-acrylic acid ester copolymer with EVOH improves the flex resistance (JP-A-61-220839), and shows that EVOH is α, β-unsaturated. It is known that blending a carboxylic acid anhydride-modified ethylene-carboxylic acid vinyl ester copolymer or ethylene-acrylic acid ester copolymer improves the impact resistance of EVOH (Japanese Patent Application Laid-Open No. Sho 61-823035). I have. However, these methods can improve the flex resistance and impact resistance of EVOH, but have a disadvantage that the barrier properties, particularly the gas barrier properties under high humidity conditions, are greatly deteriorated.

C. Problems to be Solved by the Invention The present invention has high gas barrier properties, particularly high gas barrier properties under high humidity conditions, and has flexibility such as drop impact resistance, bending resistance, air back prevention, and skin pack packaging suitability. It is intended to provide a resin composition and a laminate having excellent heat resistance.

D. Means for Solving the Problems The present inventors have proposed EVOH (A) and an olefin-based resin (E) having an ethylene component content of 20 to 65 mol% and a syndiotacticity of 55 mol% or more in diat representation. B) and the weight ratio of (A) to (B) is 93: 7
~ 60:40 resin composition, compared with the conventional composition consisting of EVOH and olefin resin, gas barrier properties,
In particular, it is a flexible resin composition having a remarkably high gas barrier property under high humidity conditions, and a laminate including at least one layer of the resin composition has a drop impact resistance, a bending resistance, an air back prevention property, a skin pack packaging. The present inventors have found that the laminate is extremely useful as a laminate excellent in suitability and the like, and have completed the present invention.

In the present invention, it is important that the content of the ethylene component is 20 to 65 mol%. 20 ethylene content
If it is less than mol%, the gas barrier properties of the resin composition are greatly impaired under high humidity conditions, and a molded article having good appearance cannot be obtained, probably because of poor compatibility with polyolefin. On the other hand, if it is more than 65 mol%, the gas barrier property of the composition is significantly impaired regardless of the relative humidity. A more preferred range of the content of the ethylene component is 25
6060 mol%, furthermore 25-50 mol%.

Next, it is extremely important that the syndiotacticity is at least 55 mol% in order for the resin composition of the present invention to exhibit high barrier properties. If the syndiotacticity is less than 55 mol%, the gas barrier properties will be impaired as will be apparent from the examples described later. Although the upper limit of the syndiotacticity is not particularly limited, it is 65 mol%, and more preferably 70 mol% from the viewpoint of production. here,
The syndiotacticity is based on a diat representation, and is calculated from the integrated intensity ratio of the hydrogen peak of the hydroxyl group existing at 4.0 to 4.7 ppm in ¹ H-NMR.

Furthermore, in the present invention, the melt index of EVOH (the value measured under the conditions of a temperature of 190 ° C. and a load of 2160 g; hereinafter referred to as MI) is not particularly limited, but is preferably 0.1 to 50 g / 10 minutes, more preferably 0.5 to 20 g.

In the present invention, the ethylene-vinyl alcohol copolymer is produced, for example, by the following method.

That is, it is a method of copolymerizing ethylene and a vinyl ester represented by the formula (I), and saponifying the obtained copolymer.

Here, R ¹ and R ² represent hydrogen or a hydrocarbon group, and R ³
Represents a hydrocarbon group, and examples of the hydrocarbon group include methyl,
A lower alkyl group such as ethyl, propyl, butyl and t-butyl; an aryl group such as phenyl; a C1-C18 hydrocarbon group such as a cycloalkyl group such as a cyclohexyl group. Among them, R ¹ , R ² , and R ³ are each preferably a lower alkyl group, particularly preferably a methyl group. That is, the vinyl ester component is most preferably vinyl pivalate in which R ¹ , R ² , and R ³ are all methyl groups.

Copolymerization of ethylene-vinyl ester includes bulk polymerization,
It is carried out by solution polymerization, suspension polymerization, or emulsion polymerization, but may be carried out under the conditions of 0 ° C to 100 ° C, preferably 30 ° C to 60 ° C, by solution polymerization in the presence of a bulk or a solvent. preferable. Polymerization rate is 20-80
%, Preferably 30 to 60%. In the case of solution polymerization, the solvent concentration is 50% or less, preferably 30% or less.

The solvent used in the solution polymerization is preferably an alcohol, and is usually methanol, ethanol, propanol,
Lower alcohols such as t-butanol are preferred. These solvents can be used alone or in combination of two or more. As the copolymerization operation, any of a batch system and a continuous system can be used, but a flow system operation using a stirring and mixing type polymerization tank is preferable.

The ethylene content of the ethylene-vinyl ester copolymer is determined by the vinyl ester present in the system and the amount of dissolved ethylene in the solution, and the latter depends on the ethylene pressure and temperature in the system. It is well known that when performing polymerization in a batch system, the copolymer composition fluctuates with the degree of polymerization in accordance with the copolymerization reactivity ratio, but one or both monomers are used so that the monomer composition is constant. In order to obtain a copolymer having a uniform copolymer composition, it is more preferable to employ a semi-batch method in which a polymer is added. An example of a method for calculating the amount of addition at this time is RJHanna (Industrial and Engineering Chemistry).
istyr vol.49,208 (1957)). In the case of the continuous method, a one-stage flow-type reaction system of a complete mixing type in which a stirring and mixing tank is used as a copolymerization reaction tank is preferable. For this reason, it is more preferable to carry out the reaction while adding the monomers to the second and subsequent tanks so that the monomer composition in the copolymerization tank at each stage becomes constant.

In the copolymerization reaction, a radical polymerization initiator is used, for example, 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 2,4,4-trimethylvaleronitrile, 2,2 Nitriles such as' -azobis-isobutyronitrile, carbonates such as di-n-propylperoxycarbonyl, bis-4-tert-butylcyclohexylperoxydicarbonate, bis-2-ethyl-hexylperoxydicarbonate And peroxides such as acetylcyclohexanesulfonyl peroxide, benzoyl peroxide and lauroyl peroxide. The copolymer thus obtained is then subjected to a saponification reaction.

Generally, vinyl esters having a bulky group in the side chain as represented by the formula (I), for example, vinyl pivalate, are not easily hydrolyzed due to their steric hindrance, and are usually used in copolymers with ethylene. Alkali saponification under conditions such as those performed for ethylene-vinyl acetate copolymers does not provide sufficient saponification. Therefore, it is preferable to saponify under the following conditions.

First, it is important to perform saponification in the absence of oxygen or in the presence of an antioxidant, and furthermore, the molar ratio of the amount of basic substance / the content of vinyl ester unit is 0.1%.
It is important that the saponification temperature is 60 ° C. or higher.

Here, the absence of oxidation is typically represented by a method of performing replacement by an inert gas (such as nitrogen). The antioxidant is not particularly limited as long as it does not adversely affect the saponification reaction and does not lose the antioxidant effect in the saponification system. Compound represented by <IRGANOX 1010 (manufactured by Ciba-Geigy Japan)> Hindered phenolic antioxidants such as the compound {IRGANOX 1098 (manufactured by Nippon Ciba Geigy)}, phenolic antioxidants such as hydroquinone, SANOL LS-
Hindered amine-based antioxidants such as 770 (manufactured by Nippon Ciba Geigy) are typical examples.

The saponification reaction is performed in the presence of a basic substance, and any of a transesterification reaction and a direct saponification reaction can be selected according to the type, concentration, and solvent type of the basic substance.
Examples of the basic substance include strong bases such as sodium hydroxide, potassium hydroxide, and calcium hydroxide, and metal alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, and potassium-t-butoxide. No. The molar ratio of the amount of the basic substance used / the content of the vinyl ester unit is represented by a molar ratio to the vinyl ester unit contained in the copolymer, and is 0.1 to 10, preferably 0.5 to 3. This additional amount varies depending on the target degree of saponification, degree of polymerization, solvent, type of basic substance, etc., but generally below 0.1 the saponification degree does not increase, and above 10 the saponification degree decreases during the saponification reaction. Occurs remarkably. The amount of the basic substance to be used may be different from those in the case where the monomer unit other than the copolymer contains a group that reacts with the basic substance (for example, a carboxyl group) or when the antioxidant reacts with the basic substance. Is set by compensating for the amount consumed.

The saponification temperature is 60 ° C or higher, preferably 60 to 140 ° C,
More preferably, it is 80 to 120 ° C.

The saponification reaction time is appropriately set depending on the target degree of saponification, polymer concentration, solvent, basic substance, temperature and the like. After completion of the saponification, it is preferable to immediately neutralize the basic substance remaining in the reaction system with an acid. Acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and carbonic acid,
Organic acids such as formic acid, acetic acid, benzoic acid and the like can be mentioned. Organic acids are preferred, and acetic acid is most preferred. If the basic substances remaining in the reaction system are not neutralized after completion of saponification,
The degree of polymerization of the copolymer decreases.

The solvent used at the time of saponification is a solvent capable of dissolving or swelling the ethylene-vinyl ester copolymer, and desirably a solvent capable of dissolving the basic substance and the polymer after saponification. Solvents having these properties include cyclic ethers such as tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone and ethyl isobutyl ketone; sulfoxides such as dimethyl sulfoxide; amides such as dimethylformamide; and aromatics such as toluene and benzene. Group hydrocarbons; alcohols such as methanol, methanol, t-butanol, n-propanol, iso-propanol, sec-butanol and cyclohexanol;
Particularly, tetrahydrofuran, methyl ethyl ketone, t-butanol and the like are preferable. These may be used alone or in combination of two or more.

The concentration of the ethylene-vinyl ester copolymer in the solvent solution in the saponification system is appropriately determined according to the degree of polymerization of the copolymer, and is usually between 3 and 70% by weight.

The saponification degree of the vinyl ester component represented by the formula (I) of EVOH obtained by saponification by such a method is 90 mol% or more, preferably 98 mol% or more, and most preferably 99 mol% or more. The higher the degree of saponification, the better the thermal stability and the better the gas barrier properties. In addition, the EVOH
As long as the object of the present invention is not impaired, propylene, α-olefins such as isobutene, olefinic unsaturated monomers containing silicon, acrylic acid, methacrylic acid,
Unsaturated carboxylic acid such as maleic acid or a salt thereof, or an ester thereof, or ethylene such as vinyl acetate and a comonomer other than the above formula (I) may be contained as a copolymerization component.

In the present invention, as the olefin-based resin, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, propylene-butene-1 copolymer, polypentene-1, a copolymer mainly composed of these olefins, for example, An ethylene-vinyl acetate copolymer or a saponified product thereof having an ethylene content of 70 to 95 mol%, preferably 80 to 95 mol%, an ethylene-acrylic acid ester copolymer, an ion-crosslinked olefin polymer, or the like; The above mixtures are illustrated. Of these, polyethylene, ethylene-vinyl acetate copolymer or a saponified product thereof is particularly preferably used. The olefin resin may be modified with an epoxy group-containing monomer such as glycidyl methacrylate or the like, or a silicon-containing monomer such as vinyltrimethoxysilane or triethoxysilane, for example, in an amount of about 5 mol% or less.

The resin composition of the present invention is a mixture of EVOH (A) and an olefin resin (B), and it is important that the weight ratio of (A) and (B) is from 93: 7 to 60:40. is there. When the blending ratio of the olefin-based resin (B) is less than 7% by weight, flexibility such as drop impact resistance and bending resistance is poor. On the other hand, if it exceeds 40% by weight, the gas barrier properties are significantly impaired, and the appearance of the molded article becomes poor.

In the present invention, as a method for mixing the EVOH (A) and the olefin-based resin (B), there is a method using a Banbury mixer, a single-screw or twin-screw extruder, a Brabender plastmill, or the like. The molding may be performed while being supplied to various molding machines and kneaded with the molding machine. When mixing them, a plasticizer, a lubricant, a filler, an antioxidant, an antistatic agent, a colorant, various resins, and the like may be added as long as the effects of the present invention are not impaired.

The resin composition of the present invention is preferably used in a laminate. As the resin to be laminated with the resin composition of the present invention, polyethylene, polypropylene, ethylene-propylene copolymer, olefin-based resin such as ethylene-vinyl acetate copolymer, thermoplastic polyester such as polyethylene terephthalate, 6-nylon, 6 Polyamides such as 1,6-nylon, polystyrene, polyvinyl chloride, polycarbonate, ordinary EVOH (obtained by saponifying an ethylene-vinyl acetate copolymer), polyvinyl alcohol and the like, or a mixture of two or more thereof are preferred. Of these,
Particularly preferred are low moisture permeable thermoplastic resins, especially polyethylene, polypropylene, ethylene-propylene copolymer, thermoplastic polyester, polystyrene and polycarbonate. The layer configuration of the laminate is as follows: resin composition of the present invention / thermoplastic resin, thermoplastic resin / resin composition of the present invention / thermoplastic resin, thermoplastic resin / resin composition of the present invention /
Thermoplastic resin / resin composition of the present invention / thermoplastic resin, etc., and the resin composition of the present invention and the thermoplastic resin may each be a single layer, or may be a multilayer in some cases. Good. If necessary, an adhesive resin may be arranged between the layers of the laminate. The adhesive resin is not particularly limited, but may be polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene, or the like. -Acrylic acid ester or the like modified with an ethylenically unsaturated acid or an acid anhydride thereof, particularly a maleic anhydride-modified or maleic anhydride-modified unmodified polymer blended, more preferably Used.

The resin composition of the present invention can be formed into a film, a sheet, a tube, a bottle, or the like as a laminate, and the thickness configuration of each layer is not particularly limited, but the resin composition layer of the present invention has a thickness of 300 μ or less. Preferably, it is 200 μm or less.

The method of forming the laminate of the present invention is not particularly limited, and examples thereof include a co-extrusion method, an extrusion lamination method, and a dry lamination method, and the characteristics of the resin composition of the present invention are particularly high according to the co-extrusion method. It is preferable because it can be exhibited.

The laminate thus obtained can be used as a container with excellent drop impact resistance, a tube with excellent air back prevention, a bag in box with excellent bending resistance, and a film with excellent skin pack suitability. it can.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. “Parts” or “%” in the examples are on a weight basis unless otherwise specified.

E. Examples Example 1 Ethylene content 32 mol%, saponification degree 99.7 mol%, syndiotacticity 61 mol%, MI (190 ° C., 2160 g) 1.8 g / 10 produced as EVOH (A) under the conditions described below. Minute EVO
H, an olefin resin (B), an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% by weight and a MI (190 ° C., 2160 g) of 2.0 / 10 minutes as the olefin resin (B); Were evaluated for film surface and various physical properties.

(1) Production of EVOH A pressure-resistant polymerization tank was charged with 100 parts by weight of vinyl pivalate, 23 parts by weight of methanol, 7.5 parts by weight of ethanol, and 0.065 parts by weight of 2,2 'azobisisobutyronitrile as a polymerization initiator. After oxygen was replaced with ethylene, the ethylene pressure was maintained at 25 kg / cm ² , polymerization was carried out at 60 ° C. with stirring for 5 hours, and then a polymerization inhibitor was added. The conversion of vinyl pivalate was 50%. Next, unreacted ethylene was purged out of the tank, and unreacted vinyl pivalate was distilled off at 60 ° C. under reduced pressure. Next, 30 parts by weight of the ethylene-vinyl pivalate copolymer was placed in a pressure-resistant saponification tank together with 450 parts by weight of tetrahydrofuran, and the mixture was heated to 60 ° C. while blowing nitrogen.
And dissolved. Then, a solution consisting of 78 parts by weight of potassium hydroxide and 225 parts by weight of methanol was prepared.After removing oxygen, the solution was charged into a pressure-resistant saponification tank.
The saponification reaction was performed at 75 ° C. for 75 minutes with stirring. Next, the saponified product was thoroughly washed with methanol and pure water, and dried at 80 ° C. for 5 hours and further at 105 ° C. for 15 hours in nitrogen. The analytical values of EVOH thus obtained are as described above. The measurement of the ethylene content, the degree of saponification, and the syndiotacticity were carried out using ¹ H-NMR using d ₆ -dimethylsulfoxide (DSMO) as a solvent. The syndiotacticity was calculated from the integrated intensity of the hydroxyl hydrogen peak present at 4.9 to 4.7 ppm.

(2) Production and film formation of a resin composition 70 parts by weight of the above EVOH and 30 parts by weight of an ethylene-vinyl acetate copolymer having an ethylene content of 88 mol% were dry-blended, and subjected to temperature control using a 30 mmφ bidirectional twin screw extruder. Pelletized at 220 ° C. Then, using this pellet, the extruder temperature was set to 18 by a film forming machine consisting of a 40 mmφ extruder and a T die.
Film formed at 0-220 ° C, T-die temperature 215 ° C, thickness 20μ
Film was obtained.

(3) Evaluation of film surface and various physical properties
The results were ranked in three stages of A to C shown in the table.

The loop stiffness is a 20%, 65% rebound force when a 15mm wide film is bent into a 60mm long loop using a Toyo Seiki loop stay ness tester and the loop is compressed to a 20mm diameter. It was measured under the condition of RH. The loop stiffness is important as a measure of the air back prevention. It is considered that the smaller the loop stiffness, the better the air back prevention.

The flex resistance was evaluated by using a gelbo flex tester manufactured by Rigaku Kogyo Co., Ltd., and measuring a film of 12 inches × 8 inches in diameter.
3.5 inch cylindrical shape, grip both ends, initial grip interval 7 inch, maximum grip interval 1 inch, first 3.5 inches of stroke, 440 degree twist, then 2.5 inches straight Repetitive reciprocating motion of horizontal motion at a speed of 40 times / min.
The number of pinholes was determined for the film after the repetition of the number of times.

Young's modulus is 20 ° C, 65% R according to ASTM D-882-67.
Measured under H conditions. Young's modulus is important in relation to skin packability. That is, it can be said that a skin pack having a low Young's modulus that can be stretched with a smaller force is suitable for the skin pack packaging including the stretching step.

Oxygen gas permeation amount (OTR) is 20 ° C, 65% RH and 100% R using OX-TRAN 10-15A manufactured by Modern Control.
It was measured under the condition of H.

Table 2 shows the evaluation results of the above items. A film-formed product of the resin composition has a good film surface, and is excellent in loop stiffness, bending resistance, flexibility represented by Young's modulus, and gas barrier properties.

Comparative Example 1 Ethylene content 32 mol%, degree of saponification 99.7 mol%, syndiotacticity 61 mol%, MI (190 ° C., 2160 g) 1.
A film was formed in the same manner as in Example 1 except that EVOH alone was used at 8 g / 10 minutes, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. Although the film surface and the gas barrier were good, the flexibility was extremely poor.

Comparative Example 2 Ethylene content of 32 mol% as EVOH (A), saponification degree
99.5 mol%, syndiotacticity 52 mol%, MI
(190 ° C., 2160 g) A film was formed in the same manner as in Example 1 except that a saponified ethylene-vinyl acetate copolymer of 1.6 g / min was used, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. Although the film surface and flexibility are good,
The gas barrier properties under high humidity (100% RH) conditions were poor.

Example 2 Using EVOH (A) and ethylene-vinyl acetate copolymer (B) described in Example 1, the mixing ratio was (A) :( B) =
A pellet-shaped resin composition was produced in the same manner as in Example 1 except that the ratio was 80:20 (weight ratio; the same applies hereinafter), and then a film was formed, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. The film surface, flexibility, and gas barrier properties were all good.

Comparative Example 3 Using EVOH (A) and ethylene-vinyl acetate copolymer (B) described in Example 1, the mixing ratio was (A) :( B) =
A pellet-shaped resin composition was produced in the same manner as in Example 1 except that the ratio was set to 95: 5, then a film was formed, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. Although the film surface and gas barrier properties were good, the flexibility was poor.

Comparative Example 4 Using EVOH (A) and ethylene-vinyl acetate copolymer (B) described in Example 1, the mixing ratio was (A) :( B) =
A pellet-shaped resin composition was produced in the same manner as in Example 1 except that the ratio was set to 50:50, then a film was formed, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. Although the flexibility was good, the film surface and gas barrier properties were extremely poor.

Comparative Example 5 Ethylene content 32 mol%, saponification degree 85.2 mol%, syndiotacticity 61 mol%, produced in the same manner as in Example 1 except that the saponification conditions were changed to EVOH (A).
A pellet-shaped resin composition was produced in the same manner as in Example 1 except that MI (190 ° C., 2160 g) 2.3 g / 10 minutes EVOH was used, then a film was formed, and the film surface and various physical properties of the film were evaluated. did. The results are shown in Table 2. Although the film surface and flexibility were poor, the gas barrier properties were poor.

Example 3 Except that the saponification conditions were changed as EVOH (A), an ethylene content of 32 mol%, a degree of saponification of 94.2 mol%, a syndiotacticity of 61 mol% were produced in the same manner as in Example 1.
A pellet-shaped resin composition was produced in the same manner as in Example 2 except that EV (2.1 g / 10 minutes, MI, 190 ° C., 2160 g) was used, and a film was formed, and the film surface and various physical properties were evaluated. The results are shown in Table 2. The film surface, flexibility, and gas barrier properties were all good.

Examples 4-5 As EVOH (A), ethylene content 44 mol%, saponification degree 99.1 mol%, syndiotacticity 60 mol%, MI (190 ° C, 2160 g) 5.2 g / Saponified ethylene-vinyl pivalate copolymer for 10 minutes, ethylene content 89 mol% as olefin resin (B), degree of saponification 95 mol%, MI (190 degrees, 2160 g) 4.8 g / 10 minutes ethylene-vinyl acetate Example 1 Using Saponified Copolymer
In the same manner as described above, a pellet-shaped resin composition having a mixing ratio of (A) :( B) = 80: 20 (Example 4) and (A) :( B) = 90: 10 (Example 5) was produced, respectively. Then, a film was formed, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. The film surface, flexibility, and gas barrier properties were all good.

Comparative Example 6 As EVOH (A), ethylene content 68 mol%, saponification degree 99.6 mol%, syndiotacticity 58 mol%, MI (190 ° C., 2160 g) 13 g / 10 min produced according to Example 1 A pellet-shaped resin composition was produced in the same manner as in Example 4 except that the saponified ethylene-vinyl pivalate copolymer was used.
Then, a film was formed, and the film surface and various physical properties of the film were evaluated. The results are shown in Table 2. Although the flexibility was good, the film surface and gas barrier properties were poor.

Example 6 Ethylene content of 27 mol%, saponification degree 98.6 mol%, syndiotacticity 62 mol%, MI (210 ° C., 2160 g) 3.5 g / 10 min as EVOH (A) produced according to Example 1. Saponified ethylene-vinyl pivalate copolymer, oleic resin (B) using linear low-density polyethylene modified with 1 mol% of glycidyl methacrylate (GMA) 1/10% for MI (190 ° C, 2160 g) 3.0 / 10 minutes Other than that, a pellet-shaped resin composition was produced in the same manner as in Example 1, and then a film was formed, and the film surface and various physical properties of the film were evaluated. Second result
It is shown in the table. The film surface, flexibility, and gas barrier properties were all good.

Comparative Example 7 As EVOH (A), ethylene content 19 mol%, saponification degree 98.5 mol%, syndiotacticity 60 mol%, MI (210 ° C., 2160 g) 1.0 g / 10 min produced according to Example 1 A pellet-shaped resin composition was produced in the same manner as in Example 6 except that the saponified ethylene-vinyl pivalate copolymer was used, and then a film was formed. The film surface and various physical properties of the film were evaluated. The results are shown in Table 2. The film surface, flexibility, and gas barrier properties under high humidity (100% RH) conditions were all poor.

Example 7 A 15 μm thick intermediate layer made of the resin composition described in Example 1 and a 30 μm thick MI (190 ° C., 2160
g) 2.1 g / 10 min. 4-Methyl-1-pentene 3.2 mol% Modified linear low-density polyethylene Surface layer, between each layer 5 μm thick vinyl acetate content 20% by weight, maleic anhydride content A laminated film having a total thickness of 85 μm arranged via an adhesive resin layer composed of 0.5% by weight of maleic anhydride-modified ethylene-vinyl acetate copolymer was prepared by using three extruders and three types of five-layer die heads. It was manufactured by a co-extrusion method. The laminated film is subjected to a gel boflex test until the occurrence of pinholes is recognized, and the oxygen gas permeation amount (OTR) at each stage until the pinholes are generated is measured by the gas permeation manufactured by Modern Control. The measurement was performed under the conditions of 20 ° C., 65% RH, and 100% RH using a volume measuring device.
Table 3 shows the measurement results. In the bending fatigue test process up to the occurrence of the pinhole, the oxygen gas permeation amount hardly changed. Further, no pinhole was observed until the bending fatigue test passed 7000 reciprocations, and after the elapse of 7,100 reciprocations, it was recognized that one pinhole had already occurred when the inspection for pinholes was performed. . The film had no streaks or satin, and had a good appearance.

Comparative Example 8 Three kinds of five-layer laminated films were produced in the same manner as in Example 7 except that EVOH alone described in Comparative Example 1 was used for the intermediate layer, and a bending fatigue test and a measurement of oxygen permeation amount were performed. The results are shown in Table 3. After 1000 reciprocations, 100 or more pinholes were generated due to poor bending fatigue resistance.

Comparative Example 9 A laminated film of three types and five layers was produced in the same manner as in Example 7, except that the resin composition described in Comparative Example 2 was used for the intermediate layer.
The bending fatigue test and the measurement of the amount of oxygen permeation were performed. The results are shown in Table 3. Although the flex fatigue resistance is good,
The gas barrier properties under high humidity (100% RH) conditions were poor.

Example 8 A 50 μm thick intermediate layer made of the resin composition described in Example 4 and 70 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5% by weight and maleic anhydride on both sides of the intermediate layer.
A container having a thickness of 300 μm and an inner / outer layer comprising 30 parts by weight of a 0.5% by weight modified ethylene-vinyl acetate copolymer (capacity: 10
) Was produced by a co-extrusion / direct blow molding method using two extruders and two types of three-layer die heads.
The container was filled with water 10 and dropped from a height of 1 m three times, but there was no destruction and good impact resistance was exhibited.

Comparative Example 10 A container having two and three layers was produced in the same manner as in Example 8, except that the intermediate layer was changed to EVOH alone as described in Example 4. The container broke in the first drop test and had poor impact resistance.

Example 9 A 20 μm thick intermediate layer made of the resin composition described in Example 4 and a 150 μm thick surface layer made of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 8% by weight were provided on both sides of the intermediate layer. And between each layer, a vinyl acetate content of 15 μm in thickness of 20% by weight,
A laminated tube having a total thickness of 350 μm disposed through an adhesive resin layer made of an ethylene-vinyl acetate copolymer modified with 0.5% by weight of maleic anhydride was connected to three extruders and three types of five-layer die heads. And manufactured by a coextrusion / direct blow molding method. The center of the body of the tube was cut at a width of 15 mm, and the repulsive force of the tube when compressed by 10 mm with a loop stiffness tester was 700 mg.

Comparative Example 11 A three-layer, five-layer laminated tube was manufactured in the same manner as in Example 9 except that the intermediate layer was changed to EVOH alone as described in Example 4. The repulsive force of the tube by the Loop Stay Fune Tester was 1500 mg, which was extremely large as compared with Comparative Example 9.

F. Effect of the Invention The resin composition of the present invention has a gas barrier property, particularly under high humidity conditions, which is significantly higher than that of a conventional resin composition comprising EVOH and an olefin-based resin, and is flexible and flexible. Yes, the laminate including at least one resin composition layer,
It is extremely useful as a container excellent in drop impact resistance, a tube excellent in air back prevention, a back in box excellent in bending resistance, a film excellent in skin pack suitability, and the like.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08L 23/00-23/36 C08L 29/00-29/04

Claims (2)

(57) [Claims] An ethylene-vinyl alcohol copolymer (A) having an ethylene component content of 20 to 65 mol% and a syndiotacticity of 55 mol% or more in diat.
And an olefin resin (B), and (A)
A resin composition wherein the weight ratio of (B) to (B) is from 93: 7 to 60:40. 2. A laminate comprising at least one resin composition layer according to claim 1.