JPH07717B2 - Ethylene-vinyl alcohol copolymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application Ethylene-vinyl which is free from pinholes, cracks, local uneven thickness, etc., and has excellent gas barrier properties during the heating and stretching of the present invention, especially the heating and high-speed stretching operation. The present invention relates to an alcohol copolymer (hereinafter referred to as EVOH) composition.

B. Conventional Technology EVOH is recognized today to be effective in fields intended for use as packaging films for food products, especially food products that require oxygen barrier properties and other products that require aroma retention. ing. However, the EVOH single film lacks toughness and has a drawback that it does not exhibit an effective barrier property against water and water vapor.

In order to improve these drawbacks, it is used in the form of a multilayer structure formed by laminating a thermoplastic resin such as polypropylene and polystyrene and various heat sealant layers represented by ionomers and ethylene-vinyl acetate copolymers. There is. By the way, when multi-layered structures (films, sheets, varisons, etc.) manufactured by various methods are secondarily processed into containers, especially when stretch molding is performed below the melting point of EVOH, small voids, cracks, and local Uneven thickness often occurs, and as a result, the oxygen barrier property of the molded container is greatly deteriorated. In addition, the appearance was poor and the container could not be used as a container for food or the like.

Therefore, conventionally, various plasticizers were added to EVOH for the purpose of preventing pinholes, cracks, etc. in the EVOH layer during heating and stretching (JP-A-53-88067, JP-A-59-20345) and blends of polyamide resins. (JP-A-52-141785, JP-A-58-1547
55, JP-A-58-36412) and the like have been studied, but it was found that in any case, the following points were not sufficiently satisfactory. That is, in a hydroxyl group-containing system, a plasticizer system represented by an aromatic sulfonamide system, etc., in order to improve the heat stretching characteristics, the addition amount is required to be 10 to 20 parts by weight with respect to 100 parts by weight of EVOH, EVOH, which is thought to be due to a large decrease in gas barrier properties and bleeding of the plasticizer
There are many problems such as a decrease in the adhesive strength between the resin layer and other resin layers, making it difficult to use.

On the other hand, a method of blending EVOH with a polyamide-based resin to impart flexibility and increasing secondary processability is known and many patents have been filed (Japanese Patent Publication No. 44-24277, Japanese Patent Publication No. 60-24813,
JP-A-58-129035, JP-B-54-38897, JP-A-58-36412 and the like) are polyamides that can improve the high-speed stretch moldability by heating.
Probably because of the large chemical reaction with EVOH, many gel-like substances are present in the molded product, and it is not possible to use because it is markedly colored. On the other hand, gel and EVOH, which have relatively little coloring, and EVOH
Although a patent for a blend system with
Because of poor compatibility with OH or heat stretchability under low speed, the appearance seems to be a good molded product without cracks, pinholes, uneven thickness, etc., but the result of measurement of gas barrier properties,
The measured values vary widely, suggesting the presence of tiny pinholes that cannot be observed with the naked eye. To make matters worse, recently, due to the increase in speed of the heating / drawing machine, the variation in the measured value of the gas barrier property greatly increased when the heating / high speed stretch molding was performed, and the reliability as a gas barrier container decreased. The result is. Therefore, gas barrier properties and reliability as barrier containers (variation)
Is good. That is, one of the important issues is the development of EVOH having good molding and processing characteristics, in which minute pinholes, cracks, uneven thickness, etc. do not occur in the EVOH layer during high-speed heating and stretching.

C. Problems to be Solved by the Invention EVOH has excellent properties as described above, but when a laminate with a thermoplastic resin is secondarily processed into a container,
Cracks, pinholes, local uneven thickness, etc. occur in the EVOH layer, greatly deteriorating the gas barrier property. Therefore, the present inventors arise when the secondary body is processed into a container or the like without impairing the excellent gas barrier property of EVOH.
An EV for multi-layer containers that has high gas barrier properties by preventing cracks, pinholes, and local uneven thickness in the EVOH layer.
As a result of intensive studies to develop an OH composition, the present invention has been completed.

D. Means for Solving the Problems The present invention provides an ethylene content of 25 to 60 mol%, a content of olefinically unsaturated monomer containing silicon represented by the following general formula of 0.0005 to 0.2 mol% and saponification. 70-95% by weight of a silicon-containing ethylene-vinyl alcohol copolymer having a degree of 90% or more, a melting point of 110-180 ° C, and a melt viscosity index of 0.1-10g.
An ethylene-vinyl alcohol copolymer composition comprising 5 to 30% by weight of a polyamide copolymer for 10 minutes.

[Wherein n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, R ² is an alkoxyl group having 1 to 40 carbon atoms,
The alkoxyl group may have a substituent containing oxygen. R ³ is hydrogen or a methyl group, R ⁴ is hydrogen or a lower alkyl group, R ⁵ is an alkylene group or a divalent organic residue in which chain carbon atoms are mutually bonded by oxygen or nitrogen, R ⁶ is hydrogen, halogen, A lower alkyl group, an aryl group or a lower alkyl group having an aryl group, R ⁷ represents an alkoxyl group or an acyloxyl group (wherein the alkoxyl group or the acyloxyl group may have a substituent having oxygen or nitrogen), R ⁸ is hydrogen, halogen, a lower alkyl group, an aryl group or a lower alkyl group having an aryl group, and R ⁹ is a lower alkyl group. E. Effects of the Invention When various sheets having a thermoplastic resin are prepared on one or both sides of the EVOH composition layer with an adhesive resin interposed therebetween, reheatability and stretching operations are performed to form secondary processing into cups and bottles. It is possible to judge the superiority or inferiority of the molding processability and the gas barrier property of the EVOH layer by measuring the appearance of the container and the gas barrier property. Therefore, the present inventors blended various plasticizers, polymers and the like with EVOH and measured the molding processability and gas barrier property of EVOH. As a result, the melting point is 110-180 ℃
And a melt viscosity index (index value measured at 190 ° C and 2160g load) of 0.1 to 10g / 10 minutes of polyamide 5 to 30
The EVOH composition blended by weight% seemed to be good at first glance, with few cracks, unevenness, uneven thickness, etc., which occur during container molding. However, when measuring the O ₂ gas barrier property of the container, the gas barrier property varies greatly depending on the measurement location, and worse, due to recent advances in molding technology, molding speed,
That is, there is a direction in which the stretching speed is greatly increased,
When high-speed stretching is performed on the sheet, the appearance is good, but the deterioration of the gas barrier property (average value) and the variation due to the measurement location increase depending on the stretching speed, which is a major problem. Is. Therefore, as a result of further diligent studies, the inventors have surprisingly found that when silicon-containing EVOH is used, there is no great difference in the gas barrier properties between the raw material and the molding container, and the barrier properties vary depending on the container. It has been found that not only can a very small thing be realized even in high-speed stretch molding, but also that it has the effect of greatly reducing gels and lumps that are likely to occur during long-term continuous operation, and arrived at the present invention. This fact is clear from the examples described later.

By the way, blending polyamide with silicon-containing EVOH has good gas barrier properties, and it is not a major cause that heating and high-speed stretch molding with less variation became possible, but introducing an active silicon compound into EVOH. This improves the compatibility of EVOH and polyamide, prevents microcracks that may occur at the blend interface during high-speed drawing, and has effective barrier properties and accuracy with little variation,
It seems that a highly reliable gas barrier container was obtained. In addition, the cause of the formation of gels and spots is not critical, but the silicon-containing EV used
Since OH has a relatively low molecular weight, the thickening effect due to cross-linking with polyamide is relatively low, so it is thought that the generation of gels and spots is suppressed to a low level.

F. More Detailed Description of the Invention The silicon compound-containing ethylene-vinyl alcohol copolymer in the present invention has an ethylene content of 25 to 60 mol%, preferably 25 to 55 mol%, and the content of the vinyl acetate component of the copolymer is The saponification degree is preferably 95 mol% or more. If the ethylene content is less than 25 mol%, the molding temperature will be close to the decomposition temperature and molding will be difficult. On the other hand, the ethylene content is 60
When it is more than mol%, the gas barrier property is deteriorated, which is not preferable. On the other hand, if the degree of saponification of the vinyl acetate component is less than 95%, the gas barrier property is lowered, and it becomes difficult to receive the effects of the present invention.

The silicon-containing olefinically unsaturated monomer used in the present invention is one or more selected from compounds represented by the following general formulas (I), (II) and (III). Can be preferably used.

[Wherein n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group or a lower alkyl group having an aryl group, and R ² is a saturated branched or unbranched group having 1 to 40 carbon atoms. It is an alkoxyl group, and the alkoxyl group may have a substituent containing oxygen. R ³ is hydrogen or a methyl group,
R ⁴ is hydrogen or a lower alkyl group, R ⁵ is an alkylene group or a divalent organic residue in which chain carbon atoms are bonded to each other by oxygen or nitrogen, R ⁶ is hydrogen, halogen, a lower alkyl group, an aryl group, or A lower alkyl group having an aryl group, R ⁷ is an alkoxyl group or an acyloxyl group (wherein the alkoxyl group or the acyloxyl group may have a substituent having oxygen or nitrogen), R ⁸ is hydrogen, halogen, lower An alkyl group, an aryl group, or
A lower alkyl group having an aryl group, R ⁹ is a lower alkyl group. More specifically, R ¹ represents a lower alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a lower alkyl group having 1 to 5 carbon atoms having an aryl group having 6 to 18 carbon atoms. , R ⁴ represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and R ⁵ represents an alkylene group having 1 to 5 carbon atoms or a chain carbon atom bonded to each other by oxygen or nitrogen 2
Represents a valent organic residue, R ⁶ is hydrogen, halogen, or a carbon number of 1 to 1.
5 is a lower alkyl group having 5 to 5 carbon atoms, an aryl group having 6 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R ⁷ is an alkoxyl or acyloxyl group having 1 to 40 carbon atoms. (Here, the alkoxyl group or the acyloxyl group may have a substituent having oxygen or nitrogen.), And R ⁸ is hydrogen, halogen, or a carbon number of 1.
To a lower alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R ⁹ is a lower alkyl group having 1 to 5 carbon atoms. Indicates.

By the way, the content of silicon compound is 0.0005 to 0.2 mol%,
Particularly, the range of 0.001 to 0.1 mol% is preferable. Content is 0.
[0005] If the amount is less than 5,000 mol%, the effect of improving the moldability during polyamide blending is not sufficient. On the other hand, the content of silicon compounds is 0.2
If it is more than mol%, the lumps and gels are likely to be developed and the film-forming property is deteriorated. Here, the silicon content means the amount (mol%) of the silicon-containing monomer in the silicon-containing monomer-vinyl acetate-ethylene copolymer.

EVOH in the present invention has a melt viscosity index (melt index) of 190 ° C. measured by ASTM D-1238-T,
0.05-10g / 10min is preferable at a load of 2160g, especially 0.1-10
Those having g / 10 minutes are preferably used.

Further, EVOH in the present invention may contain another third substance as a copolymerization component within a range that does not affect the characteristics of the present invention. Examples of the third substance include α having 3 or more carbon atoms.
-Olefin, acrylic acid, meth-acrylic acid and esters of these acids.

As the polyamide used in the present invention, 6-nylon, 6,6 nylon, 6/1 which is produced by polycondensation reaction of aminocarboxylic acid or polycondensation reaction of dibasic acid and diamine
Examples thereof include 2 nylon, 6,10 nylon, 6,9 nylon, 11 nylon and copolymers thereof, and block copolymers such as polyether and polyester. Especially 6 nylon, 6,6 nylon, 6/12 nylon, 6,9 nylon, 12
Nylon-based polyether / polyamide block copolymers are effective. It is more preferable that the content of 6-nylon is low in order to prevent thermal stability, that is, to prevent the formation of spots and gels during film formation. There is a tendency that the barrier property is deteriorated and the dispersion of measured values is increased. Further, the melting point of polyamide is 110 to 180 ° C, and the melt viscosity index (MI) (value measured at 190 ° C under a load of 2160g) is 0.1 to 10g.
Only when it is / 10 minutes, it is possible to obtain a good multi-layered container having a good appearance and little variation in gas barrier property and gas barrier property during high-speed heating and stretching. The amount of polyamide added to EVOH is 5 to 30% by weight, preferably 7 to 25% by weight. If the addition amount is 5% by weight or less, the effect of improving the moldability is not sufficient and cracks and unevenness easily occur. On the other hand, when it is 30% by weight or more, the gas barrier property is significantly lowered, and it cannot be used as a gas barrier container.

The blending method of EVOH and polyamide is not particularly limited, but dry blending EVOH and polyamide, a method of pelletizing and drying with a Banbury mixer single or twin screw extruder, or EVOH, both polyamide. A dissolving solvent such as water-methanol,
After the solution-blending with a water-phenol mixed solvent, the solvent is removed and dried. The blend is uniform,
In addition, if gel or lumps are mixed during the blending operation, the EVOH blend layer may be broken or uneven during heat stretch molding, so an extruder with a high degree of kneading should be used for heat blending with an extruder. , N ₂ seal of hopper mouth, low temperature extrusion is preferable. Also, solution blending is most preferred. When the blended pellets are molded into a 50μ sheet by a hot press at 220 ° C and the nylon particle size is measured, the particle size of 0.1μ or less is 50% or more, preferably 0.05.
It is desirable that μ is 50% or more. On the other hand, when these are mixed, other additives (various resins, antioxidants, plasticizers, coloring agents, etc.) can be freely used within the range that the effects of the present invention are not impaired. Especially the thermal stability of the resin,
As a measure to prevent gel generation, hydrotalside compounds,
It is preferable to add 0.01 to 1% by weight of a hindered phenol-based or hindered amine-based heat stabilizer.

The EVOH composition of the present invention can be molded into an arbitrary molded article such as a film, a sheet, a tube and a bottle by a well-known melt molding method and compression molding method, but as described above, the composition has a multilayer structure. Since remarkable features are exhibited when used as a single layer, description will be added to this point below.

The thermoplastic resin used on at least one surface of the composition layer of the present invention may be a resin that can be stretch-molded at the following temperature, polypropylene resin, polystyrene resin,
Polyamide resin and polyvinyl chloride resin are suitable.

When the melting point of EVOH is X ° C and the heating and drawing temperature of the thermoplastic resin is Y ° C. X-10 ≧ Y ≧ X-110 When Y is higher than (X-10) ° C, EVOH is softened and melted during molding. Usually, molding is possible without adding additives. On the other hand, when Y is (X-110) ° C or lower, the glass transition temperature (Tg) of the thermoplastic resin becomes room temperature or lower, so that the shape stability and dimensional change of the molded product at room temperature are large, and the molded product is resistant to use. Absent.

As a method for obtaining a multilayer structure, an extrusion laminating method, a dry laminating method, a coextrusion laminating method, a coextrusion sheet forming method (feed block or multi-manifold method) is used to bond the EVOH composition and a thermoplastic resin through an adhesive resin. Etc.), co-extrusion pipe making method, co-injection method, various solution coating methods, etc. to obtain a laminated body, and then using a vacuum pressure air deep drawing machine, a biaxial stretching blow machine, etc., within the range below the melting point of EVOH. A method of reheating and performing a stretching operation, or a method of subjecting the laminate (sheet or film) to a biaxial stretching machine and heating and stretching, and a method of co-injection biaxially stretching an EVOH composition and a thermoplastic resin. Can be given.

Further, the thickness configuration of the multilayer structure is not particularly limited, but in consideration of moldability and cost,
The thickness ratio of the EVOH layer to the total thickness is preferably about 2 to 20%.

In addition, the structure of the multilayer structure includes EVOH composition layer / adhesive resin layer / thermoplastic resin layer, thermoplastic resin layer / adhesive resin layer / EVOH composition layer / adhesive resin layer / thermoplastic resin layer. It can be given as a representative one. When thermoplastic resin layers are provided on both outer layers, the resins may be different or the same.

Here, the adhesive resin is not particularly limited as long as it can be stretch-molded at a temperature equal to or lower than the melting point of EVOH and can bond the EVOH composition layer and the thermoplastic resin layer. Saturated carboxylic acid or its anhydride (eg maleic anhydride) added or grafted polyolefin (eg polyethylene, polypropylene), ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester (eg methyl ester, ethyl ester) copolymer Examples include polymers.

In the present invention, the heat-stretched multilayer structure is a container such as a cup or a bottle or a sheet or film obtained by heat-stretching as described above, and heating is necessary for heat-stretching the multilayer structure. Any method may be used as long as it is allowed to stand at a temperature for a predetermined time so that the multilayer structure is thermally substantially uniform, and in consideration of operability, a method of heating and homogenizing with various heaters is preferable. The heating operation may be performed at the same time as the stretching, or may be performed before the stretching. Stretching is a container in which a multilayer structure that has been heated thermally uniformly is chucked, plugged, vacuum-pressurized, blown, etc.
It means an operation of uniformly molding into a cup, sheet or film, and either uniaxial stretching or biaxial stretching (simultaneous or sequential) can be used. The stretching ratio and the stretching speed can be appropriately selected according to the purpose. In the present invention, the high-speed stretching is a method of uniformly forming a container or a film at a high stretching speed of 5 × 10 ^50/0 / min or more. Means that the molded article does not necessarily have to be oriented.

The water content of the EVOH composition layer, which is a constituent of the multilayer structure in the present invention, is not particularly limited during heating and stretching, but it is preferably 0.01 to 10% or less.

The thus obtained heat-stretched multilayer structure of the present invention has no pinholes, cracks, or uneven thickness in the EVOH composition layer, and therefore has very good gas barrier properties and very little variation. It is effective for food packaging containers or containers that require aroma retention.

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

G. Example 1 In a polymerization tank with a stirrer having a capacity of 10 liters and having a cooling coil inside, continuous polymerization was carried out under the following conditions to obtain a silicon-containing ethylene-vinyl acetate copolymer.

Vinyl acetate supply 480g / hr Methanol supply 40g / hr Vinyl-tri-methoxysilane supply 355mg / hr 2,2'-azobisisobutyronitrile 33mg / hr Polymerization temperature 77 ℃ Polymerization tank ethylene pressure 60kg / cm ² G Average residence time 6 hrs The polymerization rate of vinyl acetate was about 50%. The copolymerization reaction liquid was supplied to a discharge column, and unreacted vinyl acetate was removed from the top of the column by introducing methanol vapor from the lower part of the column to obtain a 45% methanol solution of the copolymer. The copolymer had a vinyltrimethoxysilane unit content of 0.02 by nuclear magnetic resonance analysis.
It was confirmed to contain 7 mol%, vinyl acetate units 59.5 mol% and ethylene units about 40.5 mol%. A methanol solution of the copolymer was introduced into a tower-type saponification reactor, and sodium hydroxide was further supplied to the reactor so that the molar ratio to the vinyl acetate component contained in the copolymer was 0.05.
Methanol vapor was sucked in from the lower part of the tower, saponification reaction was performed while removing by-produced methyl acetate from the top of the tower, and a methanol solution of modified EVOH was obtained from the bottom of the tower. After blowing a mixed vapor with a weight ratio of methanol / water = 7/3 into the methanol solution to change the solvent composition in the solution to a water / methanol mixed system,
The EVOH was isolated as pellets by discharging into a 10% aqueous solution of methanol at 5 ° C in the form of strands, solidifying and precipitating, and cutting. After thoroughly washing with water, it was immersed in dilute acetic acid water and dried at 65 ° C to 110 ° C. The saponification degree was 99.3 mol%.

6 / 12-nylon with a caproad content of 60 wt% (m.
p.l55 ° C, MI = 4g / 10min) was blended at 15% and extruded into pellets at 200 ° C under N ₂ with a twin screw type vent type 40φ extruder. The obtained pellet was dried at 80 ° C. for 8 hours. Feed block type 3 using this pellet
A 5-layer coextrusion apparatus was used to prepare a sheet. Seat structure is polypropylene on both outermost layers (Mitsubishi Noblen MA-6)
Is 800μ and the adhesive resin layer (Mitsubishi Yuka Modec P-330
F (maleic anhydride modified polypropylene type) is 50μ each, and the innermost layer (center) is the EVOH layer 50μ.

The obtained sheet is subjected to a vacuum pressure forming machine (drawing speed: 9
^{Thermoforming} (SPPF molding) was performed at 155 ° C. (× 10 ^50/0 / min). The obtained molded product had good transparency and appearance, and was free from cracks and uneven thickness. The gas barrier property of this container at 20 ° C-65% RH was measured (Mocon 10/50 type) 0.7cc
Not only does it show a very good gas barrier property of 20 μ / m ² · 24 hr · atm, but the dispersion of the measured values (R = maximum value-minimum value) when measuring 10 samples is 0.1 cc · 20 μ / m ² · 24hr
・ It was a very small and very good barrier container.

Comparative Example 1 In Example 1, the ethylene content was 41 mol%,
Saponification degree 99.3 mol%, MI 1g / 10min Silicon-free E
When VOH was used and carried out in the same manner as in Example 1, the sheet E
Many gels were seen in the VOH layer. In the draw-molded container, unevenness and cracks were found around the gel. Also, the O ₂ gas barrier property was measured to be 1.9 cc · 20 μ / m ² · 24 hr · atm (20 ° C
-65% RH), and the variation (R) of the measured values of 20 samples was as large as 5 cc · 20 μ / m ² · 24 hr · atm, and there was a problem in reliability as a barrier container.

Comparative Example 2 The procedure of Example 1 was repeated except that the amount of polyamide added was changed to 3% by weight. As a result, the draw-molded container has cracks and uneven thickness, which is problematic in appearance and has an O ₂ gas barrier property of 1.2cc ・ 20μ / m ²・ 24hr ・ atm.
(20 ° C-65% RH), which was high, and a good barrier container could not be obtained.

Example 2 In Example 1, EVOH was changed to the following conditions.

Using the same polymerization tank as in Example 1, continuous polymerization was carried out under the conditions shown below.

Vinyl acetate supply 440g / hr t-butanol supply 60〃 2,2'-azobis- (2,4-dimethylvaleronitrile) 11
0mg / hr 3-acrylamido-propyltrimethoxysilane 150m
g / hr Polymerization temperature 60 ° C. Average residence time 8 hrs Polymerization tank ethylene pressure 46 kg / cm ² G The polymerization rate of vinyl acetate was about 55%. It was confirmed by nuclear magnetic resonance analysis that the copolymer contained 0.013 mol% 3-acrylamido-propyltrimethoxysilane units, 65 mol% vinyl acetate units, and about 35 mol% ethylene units.

In the same manner as in Example 1, saponification, isolation, post-treatment, and drying were performed to obtain modified EVOH. Saponification degree is 99.2 mol%
And MI was 0.7 g / 10 minutes.

In addition, polyamide is made of 12 nylon-polyether elastomer (polyoxytetramethylene content 50%, mp = 160
C., MI = 2 g / 10 min), and polypropylene was changed to polystyrene (Idemitsu Styrol MA-6), and the same procedure as in Example 1 was performed. As a result, the thermoformed container at 130 ° C has no cracks, uneven thickness, etc., and is not only good in appearance, but the O ₂ gas barrier property of the container at 20 ° C-65% RH is 0.5cc ・ 20μ / Good at m ² · 24 hr · atm, and also 20
The variation of the barrier measurement value of each container is 0.2cc ・ 20μ / m
^It was as small as ²・ 24hr ・ atm and showed good barrier properties.

Comparative Example 3 Obtained by polymerization and saponification in Example 2 without adding 3-acrylamido-propyltrimethoxysilane.
EVOH (ethylene content 34 mol%, saponification degree 99.6 mol%, MI
8.9 g / 10 minutes), and carried out in the same manner as in Example 2,
Although it was a good container with almost no cracks or uneven thickness, the O ₂ gas barrier was measured and found to be 1.2cc ・ 20μ.
It is as high as / m ² · 24hr · atm, and the variation (R) of the measured values of 20 samples is as large as 8cc · 20μ / m ² · 24hr · atm, and there was a problem in reliability as a barrier container.

Comparative Example 4 In Comparative Example 3, when the molding speed of the vacuum / pneumatic molding machine was significantly reduced and the stretching speed was 10 ^50/0 / min, the appearance (molds, cracks, uneven ^thickness ) of the molded products was compared. Example 3
The gas barrier property (average value) of the container is slightly improved to 0.7cc ・ 20μ / m ²・ 24hr ・ atm, and the dispersion of measured values is 0.9cc ・ 20μ / m ²
・ It tended to decrease to 24hr ・ atm. This shows that the moldability and gas barrier property (variation) greatly depend on the molding speed (stretching speed). That is, recently, it is important and highly desired that the stability and reliability of the quality of the molded product due to the increase of the molding speed, and it is clear from this comparative example.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location (C08L 29/04 77:00)

Claims (1)

[Claims] 1. A silicon-containing ethylene-vinyl compound having an ethylene content of 25 to 60 mol%, a silicon-containing olefinically unsaturated monomer content of 0.0005 to 0.2 mol%, and a saponification degree of 90% or more. 70-95% by weight of alcohol copolymer, melting point 110-180 ℃, melt viscosity index 0.1-10g
An ethylene-vinyl alcohol copolymer composition comprising 5 to 30% by weight of a polyamide polymer for 10 minutes. [Wherein n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, R ² is an alkoxyl group having 1 to 40 carbon atoms,
The alkoxyl group may have a substituent containing oxygen. R ³ is hydrogen or a methyl group, R ⁴ is hydrogen or a lower alkyl group, R ⁵ is an alkylene group or a divalent organic residue in which chain carbon atoms are mutually bonded by oxygen or nitrogen, R ⁶ is hydrogen, halogen, A lower alkyl group, an aryl group or a lower alkyl group having an aryl group, R ⁷ represents an alkoxyl group or an acyloxyl group (wherein the alkoxyl group or the acyloxyl group may have a substituent having oxygen or nitrogen), R ⁸ is hydrogen, halogen, a lower alkyl group, an aryl group or a lower alkyl group having an aryl group, and R ⁹ is a lower alkyl group. ]