JPH0465855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a saponified ethylene-vinyl acetate copolymer resin composition which has significantly improved low-temperature heat sealability.

The saponified ethylene-vinyl acetate copolymer with an ethylene content of 28 to 60 mol% and a degree of saponification of the vinyl acetate component of 90 mol% or more has oxygen barrier properties, oil resistance, solvent resistance, antistatic properties, fragrance retention, Because of its excellent mechanical properties, its melt-kneaded and molded products are useful for a variety of applications, including food packaging films, sheets, containers, electrical and electronic equipment parts, and mechanical appliance parts.

In such applications, the saponified material is often used as a single layer or as a composite material with the saponified material as the inner layer and a base material such as polyester, nylon, polypropylene, or paper as the outer layer.In practical use, the saponified material layer is often heat-sealed. It is done.

However, heat sealing of saponified ethylene-vinyl acetate copolymer layer usually requires 140 to 190
Since a considerably high temperature of about .degree. C. is required, there is a problem that the properties of the outer layer base material as well as the saponified layer tend to deteriorate, and a solution to this problem is required.

However, as a result of extensive research, the present inventor has found that a composition in which two types of saponified ethylene-vinyl acetate copolymers having specific compositions and properties are mixed at a specific ratio, A remarkable effect is obtained in that the heat sealing temperature can be lowered to about 90 to 130°C, preferably about 90 to 120°C, without any loss of the excellent physical properties as described above.
The inventors have discovered that the above-mentioned conventional difficulties can be completely overcome, and have completed the present invention.

That is, the resin composition of the present invention is a resin composition of two saponified ethylene-vinyl acetate copolymers having different ethylene contents, one of which has (A ₁ ) an ethylene content of 20 to 50 mol% and acetic acid of 20 to 50 mol%. A saponified ethylene-vinyl acetate copolymer with a vinyl component saponification degree of 95 mol% or more and an intrinsic viscosity of 0.6 to 1.5 dl/g, and the other (A ₂ ) is a saponified ethylene-vinyl acetate copolymer with an ethylene content of 70 to 90 mol% and a vinyl acetate component. It is a saponified ethylene-vinyl acetate copolymer having a degree of saponification of 90 mol% or more and a melting index of 2 to 50 g/10 min at 190°C and a load of 2160 g. The weight ratio of (A ₁ )/(A ₂ ) is 80/20 to 60/40, and the ethylene content in the entire composition is 35 to 60.
It is characterized by a range of mol %.

In the present invention, it is important to satisfy all of the above-mentioned conditions, and even if one of the conditions is missing, the desired effect cannot be achieved. Only when all of the above conditions are satisfied is (a) heat sealing between saponified layers at relatively low temperatures of 90 to 130 degrees Celsius, preferably 90 to 120 degrees Celsius, possible, and practically sufficient adhesive strength at such temperatures. is obtained.

(b) In the case of melt extrusion molding of films, sheets, containers, etc., the surging phenomenon is reduced and products with stable thickness can be obtained, and the resulting molded products have extremely few pinholes and fissure eyes.

(c) In injection molding, the injection pressure is stable, the molding shrinkage rate is constant, and as a result, products with stable dimensions can be obtained.

This has this effect.

In the present invention, two types of saponified ethylene-vinyl acetate copolymers are used. First, the saponified ethylene-vinyl acetate copolymer ( _A1 ) has an ethylene content of 25 to 50 mol%, preferably 28 ~50 mol%, () Saponification degree of vinyl acetate component is 95 mol% or more, preferably 97 mol% or more, () Intrinsic viscosity is 0.6 to 1.5 dl/g, preferably 0.7
Must be ~1.4 dl/g. (Values measured at 30°C with a 15% aqueous phenol solution, the same applies hereafter) If the ethylene content is too low, thermal decomposition will occur during melt molding, resulting in problems such as coloring, foaming, and frequent burning eyes. If the ethylene content is too high, properties such as oxygen barrier properties, oil resistance, solvent resistance, antistatic properties, and fragrance retention will be impaired. Even when the degree of saponification of the vinyl acetate component is low, properties such as oxygen barrier properties, oil resistance, solvent resistance, antistatic properties, and fragrance retention are impaired. Intrinsic viscosity is also an important requirement; even if the ethylene content and degree of saponification of the vinyl acetate component are within the above ranges, if the intrinsic viscosity is less than 0.6 dl/g or more than 1.5 dl/g, the film thickness will be reduced. is not stable,
Eyes also occur, making it difficult to obtain products with stable dimensions.

The saponified ethylene-vinyl acetate copolymer ( _A2 ) has an ethylene content of 70 to 90 mol%, preferably 72 to 88 mol%, and () a degree of saponification of the vinyl acetate component of preferably 90 mol% or more. 95 mol% or more; () The melting index at 190° C. and a load of 2160 g should be between 2 and 50 g/10 min, preferably between 2.5 and 45 g/10 min.

If the ethylene content is less than 70 mol%, the effect of improving low-temperature sealing properties will be poor, and if it is more than 90 mol%, the oxygen barrier properties will be greatly reduced, making it impractical. If the degree of saponification is less than 90 mol%, the oxygen barrier property decreases. If the melting index is outside the above range, the compatibility with (A ₁ ) will decrease and the physical properties of the molded product will decrease.

Furthermore, the composition of the present invention has a mixing weight ratio of (A ₁ )/(A ₂ )=80/20 to 60/40, preferably 80/
It is necessary to limit the ratio to 20 to 65/35 and to specify the ethylene content in the entire composition to be 35 to 60 mol%, preferably 35 to 55 mol%.

When (A ₁ )/(A ₂ ) is 80/20 or more, it is difficult to notice the effect of improving low-temperature heat sealability, while when it is 60/40 or less, the oxygen barrier properties and compatibility of the molded product decrease.

In addition, the ethylene content in the entire composition is 35 to 60 mol%.
It is also important to preferably specify 35 to 55 mol%.
At 35 mol% or less, water resistance, oxygen barrier properties at high humidity,
The flexibility and pinhole resistance are poor, and if the content exceeds 60 mol%, the low temperature heat sealability and pinhole resistance are maintained, but the oxygen barrier properties are greatly inferior, making both of them impractical.

In the present invention, two types of saponified ethylene-vinyl acetate copolymers are melt-kneaded to form pellets, films, sheets, containers, fibers, rods, tubes, various molded products, and the like. These pulverized products (when reusing collected products, etc.) and pellets are often used again for melt molding. As the melt-kneading method, extrusion molding (T-die extrusion, inflation extrusion, blow molding, melt spinning, profile extrusion, etc.) and injection molding are mainly employed. The melt kneading temperature is
It is often selected from the range of 170 to 270℃. The above injection molding methods include general injection molding, two-color molding, injection blow molding, etc., and can produce molded products with good dimensional accuracy.

In melt molding, in addition to the above two saponified ethylene-vinyl acetate copolymers, plasticizers (polyhydric alcohols, etc.), stabilizers, surfactants, crosslinking substances (epoxy compounds, polyvalent metal salts, inorganic or (organic polybasic acids or their salts, etc.), fillers, colorants,
An appropriate amount of fibers (glass fiber, carbon fiber, etc.) as a reinforcing material can be blended. In addition, other thermoplastic resins can be blended in appropriate amounts, such as polyolefins (low and
Medium/high density polyethylene, isotactic polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, copolymer of ethylene and α-olefin having 4 or more carbon atoms,
Ethylene-vinyl acetate copolymer or its saponified product with an ethylene content of 55 to 70 mol%, ethylene-acrylic acid ester copolymer, ionomer,
polybutene, polypentene, etc.) or modified polyolefins obtained by graft-modifying these with unsaturated carboxylic acids or derivatives thereof, polyvinyl chloride, polyvinylidene chloride, polyester, polystyrene, polyacrylonitrile, polyurethane, polyacetal, melt-moldable polyvinyl alcohol resins, etc. can be given.

When an extrusion molding method is adopted as a melt-kneading method, it is not only necessary to mold only the saponified ethylene-vinyl acetate copolymer composition, but also to separately melt-knead the composition and other thermoplastic resins. At the same time, coextrusion is often carried out by joining with a combining adapter or inside a die or outside the die. The saponified ethylene-vinyl acetate copolymer composition can also be extrusion coated onto a base film such as plastic film, metal foil, or paper. As other thermoplastic resins in the case of coextrusion, the thermoplastic resins mentioned above in the case of thermoplastic resin compounding are used, and as plastic films in the case of extrusion coating, cellophane, polypropylene film, polyamide film, etc. Films such as polyester films (which may be uniaxially or biaxially stretched, and may be coated on one or both sides with polyvinylidene chloride resin, etc.), laminate films, and the like can be mentioned. These films, containers, etc. are useful as packaging materials for various foods, medical drugs, industrial chemicals, agricultural chemicals, and the like.

Next, the resin composition of the present invention will be further explained by giving examples. Hereinafter, "parts" and "%" are expressed on a weight basis unless otherwise specified.

Example 1 (A ₁ ): Ethylene content 26 mol%, degree of saponification of vinyl acetate component 99.3 mol%, intrinsic viscosity
0.7 dl/g saponified ethylene-vinyl acetate copolymer (A ₂ ): ethylene content 85 mol%, degree of saponification of vinyl acetate component 99.5 mol%, melting index 20
g/10 min saponified ethylene-vinyl acetate copolymer The pellets of the above (A ₁ ) and the pellets of the above (A ₂ ) were mixed at a weight ratio of 80:20 (ethylene content in the total composition was 38%). % by mole), the mixture was supplied to an extruder equipped with a T-die, melted and kneaded, and extruded from the die to form a film with a thickness of 20 μm. The conditions for extrusion molding are: Extruder 40mm diameter extruder Screw Full flight screw, L/
D=25, compression ratio 3.5 T-die width 450 mm Extrusion temperature Feed zone 180°C Compression zone 210°C Metering zone 220°C Die 200°C Screw rotation speed 40 rpm Film take-up speed 25 m/min.

The obtained film was heat-sealed using a heat sealer at a pressure of 1 Kg/cm ² , a temperature of 120° C., and a time of 2 seconds. Heat sealing was performed perfectly and the sealing strength was 2500g/15mm. Also, 25℃, 75%
The oxygen permeability under RH was only 1.8cc/ ^m2・24hr・atm. Further 440° twist (3.5 inches straight)
Pinball resistance was tested 50 times under conditions of 2.5 inches of straight forward movement, but no pinballs occurred.

Example 2 (A ₁ ) has an ethylene content of 36 mol%, a degree of saponification of vinyl acetate component of 99.1 mol%, and an intrinsic viscosity of 0.77.
dl/g saponified ethylene-vinyl acetate copolymer (A ₂ ): ethylene content 73 mol%, degree of saponification of vinyl acetate component 99.5 mol%, melting index 12 g/10
The saponified ethylene-vinyl acetate copolymer was mixed in a ratio of (A ₁ ):(A ₂ )=70:30 so that the ethylene content in the composition was 47 mol%, and the mixture was prepared in the same manner as in Example 1. A film with a thickness of 20μ was produced.

The sealing strength is 2100 when heat sealed at a sealing temperature of 100℃, a pressure of 2Kg/cm ² and a sealing time of 1 second.
g/15mm. Also, the oxygen permeability is 8.3cc/ ^m2 .
There were no occurrences of 24-hour ATM pinball.

Example 3 As (A ₁ ), ester content is 32 mol%, degree of saponification of vinyl acetate component is 99.4 mol%, and intrinsic viscosity is 1.3.
dl/g saponified ethylene-vinyl acetate copolymer (A ₂ ): ethylene content 80 mol%, degree of saponification of vinyl acetate component 98.6 mol%, melting index 8.5 g/g
Using a 10-minute saponified ethylene-vinyl acetate copolymer, (A ₁ ):(A ₂ )=75:25, the ethylene content in the composition was 44 mol%, and the mixture was prepared as in Example 1. A film with a thickness of 20 μm was produced in the same manner.

The sealing strength is 2800 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is 6.4cc/ ^m2 .
During the 24-hour ATM, there were no pinball incidents.

Control example 1 (A ₁ ) has an ethylene content of 20 mol%, a degree of saponification of vinyl acetate component of 98.5 mol%, and an intrinsic viscosity of 0.82.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 87 mol%, degree of saponification of vinyl acetate component 99.1 mol%, melting index 33
g/10 minutes of saponified ethylene-vinyl acetate copolymer, (A ₁ ):(A ₂ )=94:6, and mixed so that the ethylene content in the composition was 24 mol%, Example 1
A film with a thickness of 20μ was produced in the same manner as above.

The sealing strength is 60g/cm when heat sealed at a sealing temperature of 120℃, a pressure of 2Kg/cm ² , and a sealing time of 2 seconds.
It was 15mm. Also, the oxygen permeability is 1.2cc/ ^m2・
24hr/ATM, pinhole occurrence was 250.

Control example 2 (A ₁ ) has an ethylene content of 60 mol%, a degree of saponification of vinyl acetate component of 98.5 mol%, and an intrinsic viscosity of 0.75.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 85 mol%, degree of saponification of vinyl acetate component 99.1 mol%, melting index 28
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=65:35, the ethylene content in the composition was 69 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The seal strength is 1300 when heat sealed at a sealing temperature of 110℃, a pressure of 1Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is ^330c.c./m2 .
24hr/ATM, pinhole occurrence was 13.

Control example 3 (A ₁ ) has an ethylene content of 37 mol%, a degree of saponification of vinyl acetate component of 99.3 mol%, and an intrinsic viscosity of 0.77.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 85 mol%, degree of saponification of vinyl acetate component 99.1 mol%, melting index 28
g/10 minutes of saponified ethylene-vinyl acetate copolymer, (A ₁ ):(A ₂ )=99.8:0.2, and mixed so that the ethylene content in the composition was 37 mol%. A film with a thickness of 20 μm was produced in the same manner as in 1.

The sealing strength is 50g/cm2 when heat sealed at a sealing temperature of 120℃, a pressure of 2Kg/ ^cm2 , and a sealing time of 2 seconds.
It was 15mm. In addition, the oxygen permeability is 1.9cc/ ^m2・
The number of 24hr ATM pinholes was 180.

Control example 4 (A ₁ ) has an ethylene content of 26 mol%, a degree of saponification of vinyl acetate component of 99.4 mol%, and an intrinsic viscosity of 0.80.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 48 mol%, degree of saponification of vinyl acetate component 98.3 mol%, melting index 45
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=50:50, the ethylene content in the composition was 37 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The seal strength is 1200 when heat sealed at a sealing temperature of 120℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is 1.8cc/
^m2・24hr・atm, the number of pinholes was 20.

Control example 5 (A ₁ ) has an ethylene content of 36 mol%, a degree of saponification of vinyl acetate component of 99.1 mol%, and an intrinsic viscosity of 0.55.
dl/g saponified ethylene-vinyl acetate copolymer, ethylene content as (A ₂ ) 73 mol%, degree of saponification of vinyl acetate component 99.5 mol%, melting index 12
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=70:30, the ethylene content in the composition was 47 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The seal strength is 1900 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. In addition, the oxygen permeability is 11 c.c./m ² .
24hr/ATM, pinhole occurrence was 25.

Control example 6 (A ₁ ) has an ethylene content of 36 mol%, a degree of saponification of vinyl acetate component of 99.2 mol%, and an intrinsic viscosity of 1.6.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 73 mol%, degree of saponification of vinyl acetate component 99.5 mol%, melting index 13
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=70:30, the ethylene content in the composition was 47 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The sealing strength is 1600 when heat sealed at a sealing temperature of 100℃, a pressure of 1Kg/cm ² , and a sealing time of 1 second.
g/15mm. In addition, the oxygen permeability is 10 c.c./m ² .
24hr/ATM, pinhole occurrence was 14.

Control example 7 (A ₁ ) has an ethylene content of 32 mol%, a degree of saponification of vinyl acetate component of 99.4 mol%, and an intrinsic viscosity of 1.3.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 80 mol%, degree of saponification of vinyl acetate component 98.6 mol%, melting index 1.6
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=75:25, the ethylene content in the composition was 44 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The seal strength is 1400 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 1 second.
g/15mm. Also, the oxygen permeability is 9.2cc/
^m2・24hr・atm, the number of pinholes was 30.

Control example 8 (A ₁ ) has an ethylene content of 32 mol%, a degree of saponification of vinyl acetate component of 99.4 mol%, and an intrinsic viscosity of 1.3.
saponified ethylene-vinyl acetate copolymer of dl/g, ethylene content as (A ₂ ) 80 mol%, degree of saponification of vinyl acetate component 99.1 mol%, melting index 55
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=75:35, the ethylene content in the composition was 44 mol%, and 1
A film with a thickness of 20μ was produced in the same manner as above.

The seal strength is 900 when heat sealed at a sealing temperature of 110°C, a pressure of 2Kg/cm ² and a sealing time of 1 second.
g/15mm. Also, the oxygen permeability is 8.7cc/
^m2・24hr・atm, the number of pinholes was 25.

Control example 9 (A ₁ ): ethylene content 15 mol%, saponification degree of vinyl acetate component 95.5 mol% or more, intrinsic viscosity
As a saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.65 dl/g, the ethylene content is 85 mol%, the degree of saponification of the vinyl acetate component is 96.0 mol%, and the melting index is 23.
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=70:30, the ethylene content in the composition was 36 mol%, and Example 1 A film with a thickness of 20μ was produced in the same manner as above. The seal strength is 50g/15mm when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² , and a sealing time of 2 seconds.
It was hot. Also, the oxygen permeability is 2.5cc/ ^m2・24hr・
ATM, pinhole occurrence was 230.

Control example 10 (A ₁ ) has an ethylene content of 55 mol%, a degree of saponification of vinyl acetate component of 98.5 mol% or more, and an intrinsic viscosity of
As a saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.63 dl/g, the ethylene content is 70 mol%, the degree of saponification of the vinyl acetate component is 99.2 mol%, and the melting index is 18.
Using a saponified ethylene-vinyl acetate copolymer of g/10 min, (A ₁ ):(A ₂ )=80:20, the ethylene content in the composition was 58 mol%, and Example 1 A film with a thickness of 20μ was produced in the same manner as above. The sealing strength is 2300g/15 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/ ^cm2 , and a sealing time of 2 seconds.
It was warm in mm. In addition, the oxygen permeability is 30c.c./m ²・24hr・
ATM, pinhole occurrence was 2.

Control example 11 (A ₁ ) has an ethylene content of 35 mol%, a degree of saponification of vinyl acetate component of 99.1 mol% or more, and an intrinsic viscosity of
Ethylene content 95 mol% as saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.75 dl/g, saponification degree of vinyl acetate component 98.5 mol% or more, melting index 30 g/10 min ethylene-vinyl acetate copolymer Using a saponified polymer, (A ₁ ):(A ₂ ) = 75:25, the ethylene content in the composition was 50 mol%, and a film with a thickness of 20μ was prepared in the same manner as in Example 1. was manufactured. The seal strength is 1800 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is >100c.c./
^m2・24hr・atm, the number of pinholes was 210.

Control Example 12 A saponified ethylene-vinyl acetate copolymer alone having an ethylene content of 37 mol%, a degree of saponification of the vinyl acetate component of 99.2 mol% or more, and an intrinsic viscosity of 0.78 dl/g was used in the same manner as in Example 1. A film with a thickness of 20μ was produced. The seal strength when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds is
It was 90g/15mm. Also, the oxygen permeability is 1.5cc/
^m2・24hr・atm, the number of pinholes was 110.

Control Example 13 A saponified ethylene-vinyl acetate copolymer with an ethylene content of 85 mol%, a degree of saponification of the vinyl acetate component of 97.5 mol% or more, and a melt index of 35 g/10 minutes was used, and the thickness was increased in the same manner as in Example 1. A film with a thickness of 20μ was produced. The seal strength when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds is
It was 1750g/15mm. Also, the oxygen permeability is >100
cc/ ^m2・24hr・atm, no pinholes occurred.

Control example 14 (A ₁ ) has an ethylene content of 35 mol%, a degree of saponification of vinyl acetate component of 99.3 mol% or more, and an intrinsic viscosity of
As saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.85 dl/g, the ethylene content is 50 mol%, the degree of saponification of the vinyl acetate component is 99.8 mol% or more, and the melting index is 10 g/10 min. Using saponified polymers, (A ₁ ):(A ₂ ) = 60:40, the ethylene content in the composition was 41 mol %, and a film with a thickness of 20 μm was prepared in the same manner as in Example 1. was manufactured. The seal strength is 120 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is 5.5cc/
^m2・24hr・atm, the number of pinholes was 85.

Control example 15 (A ₁ ) has an ethylene content of 25 mol%, a degree of saponification of vinyl acetate component of 98.5 mol% or more, and an intrinsic viscosity of
As saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.68 dl/g, the ethylene content is 85 mol%, the degree of saponification of the vinyl acetate component is 95.0 mol% or more, and the melting index is 25 g/10 min. Using a saponified polymer, (A ₁ ):(A ₂ ) = 50:50, mixed so that the ethylene content in the composition was 52.5 mol%,
A film with a thickness of 20 μm was produced in the same manner as in Example 1. The seal strength is 1600 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. In addition, the oxygen permeability is ^85c.c./m2 .
24hr/ATM, pinhole occurrence was 180.

Control example 16 (A ₁ ) has an ethylene content of 20 mol%, a saponification degree of vinyl acetate component of 98.5 mol% or more, and an intrinsic viscosity.
As a saponified ethylene-vinyl acetate copolymer (A ₂ ) of 0.68 dl/g, the ethylene content is 70 mol%, the degree of saponification of the vinyl acetate component is 99.1 mol% or more, and the melting index is 16 g/10 min. Using a saponified polymer, (A ₁ ):(A ₂ ) = 80:20, the ethylene content in the composition was 30 mol%, and a film with a thickness of 20 μm was prepared in the same manner as in Example 1. was manufactured. The seal strength is 45 when heat sealed at a sealing temperature of 110℃, a pressure of 2Kg/cm ² and a sealing time of 2 seconds.
g/15mm. Also, the oxygen permeability is 1.2cc/
^m2・24hr・atm, the number of pinholes was 250.

Claims (1)

[Claims] 1 ( _A1 ) Ethylene content 20 to 50 mol%, degree of saponification of vinyl acetate component 95 mol% or more, intrinsic viscosity
0.6 to 1.5 dl/g saponified ethylene-vinyl acetate copolymer and ( _A2 ) ethylene content 70 to 90 mol%,
Saponification degree of vinyl acetate component: 90 mol% or more, 190℃
It consists of a mixture with saponified ethylene-vinyl acetate copolymer with a melting index of 2 to 50 g/10 minutes at a load of 2160 g, and the mixing weight ratio is (A ₁ )/(A ₂ ).
= 80/20 to 60/40, and the ethylene content in the total mixture is 35 to 60 mol%.