JPH0735108B2 - Thermoformed product - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoformed article which is free from pinholes, cracks, local uneven thickness, and the like, and which has excellent gas barrier properties during heating and drawing, especially during heating and high speed drawing.

[0002]

2. Description of the Related Art Saponified products of ethylene-vinyl acetate copolymer (hereinafter referred to as EVOH) are used today as a film for packaging foods and the like, particularly foods that need a barrier property against oxygen, and other products that need aroma retention. It has been recognized as effective in fields intended for use in products and the like. However, EVO
The H simple substance 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 often used in the form of a multi-layer structure comprising a polypropylene layer and various heat sealant layers represented by ionomers and ethylene-vinyl acetate copolymers. .

By the way, a multilayer structure having an EVOH layer and a polypropylene layer (film, sheet, parison, etc.)
When secondary molding is applied to a container, etc., especially when stretch molding is performed below the melting point of EVOH, small voids, cracks, and local uneven thickness frequently occur in the EVOH layer, resulting in a large oxygen barrier property of the molding container. It gets worse in width. In addition, the appearance was poor, and the container could not be used as a container for food or the like.

Conventionally, various plasticizers have been added to EVOH for the purpose of preventing pinholes, cracks and the like in the EVOH layer generated during heating and stretching (Japanese Patent Laid-Open Nos. 53-88067 and 5).
9-20345), blends of polyamide resins (JP-A-52-141785, JP-A-58-154755, JP-A-58-36412) and the like are being studied, but in any case, they should be sufficiently satisfied. is not.

Further, JP-A-52-101182 discloses that the ethylene content is 50 mol% or less, the ethylene content is 50 to 90 mol% in 95 to 99.5 parts by weight of EVOH having a saponification degree of 96 mol% or more, and the saponification degree is 50 to 95%. It is described that a polyolefin laminate is laminated on at least one surface of a mixture layer containing 0.5 to 5 parts by weight of EVOH at a mol% to obtain a multilayer laminated container having excellent barrier properties and adhesiveness. A layer of a mixture of EVOH such as
Even if it is heated and stretched, it is difficult to prevent minute pinholes, cracks, uneven thickness, and the like. This is also clear from the comparative example described later.

Therefore, when a laminate of an EVOH layer and a polypropylene layer is heated and stretched, especially when heated and stretched at high speed, EV
One of the important issues is to develop an EVOH that has good molding and processing characteristics without causing minute pinholes, cracks, uneven thickness, etc. in the OH layer.

[0008]

EVOH has various excellent properties as described above, but when a laminate with polypropylene is secondarily processed into a container or the like, cracks, pinholes or local Uneven thickness occurs, and the gas barrier property is greatly deteriorated. Also, it looks bad,
It cannot be used as a food packaging container. Therefore, the present inventors prevent the generation of cracks, pinholes, local uneven thickness, etc. of the EVOH layer that would occur when the laminate is subjected to secondary processing without impairing the excellent gas barrier properties of EVOH. Then, as a result of intensive studies to develop a thermoformed product having a high gas barrier property, the present invention has been completed.

[0009]

According to the present invention, an ethylene-vinyl acetate copolymer saponified product (A) having an ethylene content of 45 to 60 mol% and a saponification degree of a vinyl acetate component of 96 mol% or more is used .
70% by weight , an ethylene content of 25 to 40% by mole, and a saponification degree of a vinyl acetate component of 96% by mole or more (B) 94 to 30% by weight of an saponified product of ethylene-vinyl acetate copolymer, and (I) to A resin composition layer satisfying the formula (III) and having a melting curve with a differential scanning calorimeter having a plurality of endothermic peaks has a polypropylene layer on at least one side, and the tensile tension of the resin composition layer with respect to the polypropylene layer. A thermoformed product having a ratio of 5 or less. 1 ≦ E ′ (B) / E ′ (A) …… (I) E ′ (A) ≦ 10 ⁹ dyne / cm ² …… (II) 0.05 ≦ MI (A) / MI (B) ≦ 20 …… (III) Dynamic viscoelasticity of E ′ (A) ... A at thermoforming temperature −10 ° C. Dynamic viscoelasticity of dyne / cm ² E ′ (B) ... B at thermoforming temperature dyne / cm ² MI (A) ・ ・ ・ A, melt index g / 10 min under 190 ° C., 2160 g load MI (B) ・ ・ ・ B, melt index g / 190 ° C. under 2160 g load 10 minutes

When various sheets having a polypropylene (PP) layer on one or both sides of the EVOH layer with an adhesive resin interposed therebetween are prepared and subjected to secondary processing into cups and bottles by reheating and stretching operations, the appearance of the container is Also, it is possible to judge the superiority or inferiority of the moldability and gas barrier property of the EVOH layer by measuring 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, an EVOH composition prepared by blending EVOH with polyamide or the like in an amount of 5 to 30% by weight is a glycol-based or amide-based plasticizer, or a polyethylene-based or ethylene-based plasticizer.
It seemed that a good molded product free from cracks and unevenness was obtained at the time of thermoforming than the EVOH composition obtained by blending the vinyl acetate copolymer and these maleic anhydride modified products. However, when the oxygen gas barrier property of the container was measured, it was found to be worse than the gas barrier property of the raw material, and worse, the measured value greatly varied depending on the container, and sometimes the barrier property was 1/10 to Even those that deteriorate to 1/50 are recognized. In particular, when the heat drawing speed during thermoforming is increased, when the thickness of the EVOH composition layer is increased,
Alternatively, this tendency becomes remarkable when the draw ratio (drawing ratio) is increased. Therefore, it poses a great problem in terms of reliability as a gas barrier container.

Therefore, as a result of further diligent studies, the present inventors have found that EVOH having an ethylene content of 45 mol% or more.
(A) and EVOH with an ethylene content of 40 mol% or less
By blending (B) with a specific amount, satisfying the above formulas (I) to (III), and further using a resin composition having a melting curve by a differential scanning calorimeter having a plurality of endothermic peaks,
It has been found that not only a thermoformed product having a good appearance can be obtained irrespective of the stretching speed, but also a thermoformed product having a deteriorated gas barrier property and less variation in measured values can be obtained.

The EVOH (A) used in the present invention has an ethylene content of 45 to 60 mol%, preferably 45 to 55 mol%, and a vinyl acetate component having a saponification degree of 96 mol% or more. It is a saponified polymer. If the ethylene content is less than 45 mol%, cracks and pinholes are likely to occur during thermoforming, and the measured gas barrier properties also vary, which is not preferable. On the other hand, when the ethylene content exceeds 60 mol%, the gas barrier property is deteriorated and the performance as a gas barrier container is insufficient, which is not preferable. Further, EVOH having a saponification degree of the vinyl acetate component of less than 96 mol% is not preferable because not only the gas barrier property is not sufficient, but also the thermal stability is poor and gel is generated during film formation. The preferred degree of saponification is 98 mol%
That is all.

On the other hand, another EVOH used in the present invention
(B) is an EVOH having an ethylene content of 25 to 40 mol% and a saponification degree of a vinyl acetate component of 96 mol% or more, preferably 98 mol% or more. When the ethylene content of (B) is less than 25 mol%, molding is performed. Is insufficient, and if it exceeds 40 mol%, the gas barrier property is also insufficient, and the saponification degree of (B) is 96.
If it is less than mol%, the gas barrier property becomes insufficient. Further, in the present invention, the resin composition of EVOH (A) and (B) is a differential scanning calorimeter (scanning speed 10 ° C. /
It is important that the melting curve according to (min) has multiple endothermic peaks. Single peak has cracks and uneven thickness
It will be.

Next, regarding the mixing ratio (weight ratio) of EVOH (A) and EVOH (B), A / B = 6/94 to 70/30
Is. When the mixing ratio is A / B <6/94 , cracks, unevenness, and pinholes are likely to occur at the time of molding the container, and the gas barrier properties also vary greatly, which is not preferable.
On the other hand, in the case of A / B> 70/30 , local uneven thickness is generated at the time of molding the container, which is not preferable in appearance. The preferred range is 7/93 ≦ A / B
≦ 45/55 .

Further, in the present invention, it is important that EVOH (A) and EVOH (B) satisfy the above formulas (I) to (III). Dynamic viscoelasticity is greatly influenced by ethylene content of EVOH, degree of saponification, melt index, etc., but E '(A)> 10 ⁹ dyne / c
If m ^2, and during the container forming, cracks, pinholes tend to occur, and the measured value of the gas barrier properties and uneven undesirably. E '(B) is 10 ¹³ dyne / cm ²
The following is preferable. Melt index ratio is M
I (A) / MI (B)> 20 or MI (A) / MI
(B) <0.05, EVOH (A) and EVOH
In the blending with (B), the dispersed particles do not become finer and become non-uniformly mixed, and thus cracks and pinholes are likely to occur at the time of molding the container, and variations in the gas barrier property become large. MI (A) and MI (B) are 0.1-20g / 1
It is selected from the range of 0 minutes, preferably 1 to 15 g / 10 minutes.

When measuring the melt index,
If the melting point is around 190 ° C or exceeds 190 ° C, it is measured at a plurality of temperatures above the melting point under a load of 2160 g, and the reciprocal of absolute temperature is plotted on the horizontal axis and the melt index is plotted on the semilogarithmic graph. The value obtained by extrapolation is the melt index value. The dynamic viscoelasticity E'at thermoforming temperatures
When E ′ (B) / E ′ (A) <1, local uneven thickness occurs during molding of the container, which is not preferable in appearance.

The preferred ranges of the above formulas (I) to (III) are as follows. 10 ≦ E ′ (B) / E ′ (A) …… (I ′) E ′ (A) ≦ 8 × 10 ⁸ dyne / cm ² …… (II ′) 0.06 ≦ MI (A) / MI (B) ≤18 …… (III´)

The blending method of EVOH (A) and EVOH (B) is not particularly limited, but E
There is a method of dry blending VOH (A) and (B) and pelletizing with a Banbury mixer single screw or twin screw extruder. The blend is uneven,
Also, if there is a mixture of gel and spots during the blending operation,
Since there is a high possibility that the EVOH blend layer will be torn or uneven during thermoforming, especially during hot stretch molding, an extruder with a high degree of kneading should be used in the heat blending by an extruder, and a N ² seal at the hopper mouth, Low temperature extrusion is preferred.

On the other hand, when these are mixed, it is free to use other additives (various resins, antioxidants, plasticizers, coloring agents, etc.) within the range where the effects of the present invention are not impaired. In particular, as a measure against the thermal stability of the resin and the prevention of gel generation, it is preferable to add 0.01 to 1% by weight of a hydrotalcite-based compound, a hindered phenol-based or a hindered amine-based thermal stabilizer.

The EVOH composition of the present invention can be formed into any thermoformed product such as a film, a sheet, a tube or a bottle by the well-known melt molding method or compression molding method. By stacking in layers,
Since remarkable features are exhibited, this point will be described below.

The PP used in the present invention is not particularly limited, and polypropylene, propylene and other comonomers can be used.
A block copolymer such as ethylene, etc.
Or a random copolymer, and further, a blended product of the above resins, and the like. Other thermoplastic resin (for example, other polyolefin such as polyethylene) may be blended with these PP.

As a method for obtaining a multilayer structure, the EVO is used.
Extrusion laminating method, dry laminating method, co-extrusion laminating method, co-extrusion sheet forming method (feed block or multi-manifold method, etc.), co-extrusion pipe forming method, co-injection method, H composition and PP via an adhesive resin A method in which a laminate is obtained by various solution coating methods or the like, and then the mixture is thermoformed, for example, a vacuum pressure air deep drawing machine, a biaxial stretching blower, or the like, is reheated to a temperature not higher than the melting point of PP, and a stretching operation is performed ( SPPF molding), melt molding performed at a melting point of PP or higher, or a method of subjecting the laminate (sheet or film) to a biaxial stretching machine and heating and stretching, and further EVOH
Examples include a method of co-injection biaxial stretching of the composition and PP.

With respect to the thickness constitution of the multilayer structure, a good molded product is obtained in the multilayer structure in which the tensile tension ratio of the EVOH layer to the PP layer is 5 or less, preferably 1 or less at the thermoforming temperature, particularly the hot stretch forming temperature. Is obtained.
When the tensile ratio is 5 or more, cracks, unevenness, etc. are likely to occur even in the EVOH composition, which is not preferable.
Here, the tensile strength of the PP layer of the multi-layer structure is a value measured at 100% elongation at the same temperature as the heat-stretching temperature at a pulling speed of 50 mm / min, a chuck interval of 50 mm, and a multi-layer structure before heating and stretching. The tensile tension of the EVOH layer is a value measured under the same conditions as described above for an EVOH single layer composed of a blend of (A) and (B). Further, these tensile tensions may be obtained by subjecting the multilayer structure after heating and stretching to hot pressing, releasing the stretching and returning to the state before heating and stretching, and measuring the state under the same conditions as described above. It is possible.

The structure of the multilayer structure is EVOH.
Typical examples are composition layer / adhesive resin layer / PP layer, PP layer / adhesive resin layer / EVOH composition layer / adhesive resin layer / PP layer. Here, the adhesive resin is EVO
There is no particular limitation as long as it can be stretch-molded at a temperature below the melting point of H and can bond the EVOH composition layer and the PP layer, but it is preferably an ethylenically unsaturated carboxylic acid or its anhydride (for example, anhydrous). Examples thereof include polyolefins (eg polyethylene, polypropylene), ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester (eg methyl ester, ethyl ester) copolymers to which maleic acid) has been added or grafted.

In the present invention, the thermoformed article, particularly the heat-stretched multilayer structure, is a container such as a cup or bottle obtained by heat-stretching as described above, or a sheet or film, and heating means The multi-layer structure may be left at a temperature necessary for heating and stretching for a predetermined time, and the multi-layer structure may be operated so that the multi-layer structure is thermally uniform. In consideration of operability, various heaters may be used. A method of heating and homogenizing is preferable. 110-230 ℃ as thermoforming temperature,
It is preferably selected from the range of 120 to 210 ° C. The heating operation may be performed at the same time as the stretching, or may be performed before the stretching. Stretching means an operation of uniformly molding a multi-layered structure that has been heated uniformly uniformly into a container, cup, sheet, or film by chuck, plug, vacuum pressure, blow, etc., uniaxial stretching, biaxial Stretching (simultaneous or sequential)
Either 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 means that the stretching speed {stretching area ratio (%) / min} is 5 × 10 ⁵ %.
It means a method of uniformly thermoforming into a container or a film at a high speed of not less than / min. The thermoformed article thus obtained does not necessarily have to be oriented.

On the other hand, with respect to the draw ratio, an area ratio of 3 or more can be expected to have a remarkable effect in the present invention. A suitable draw ratio is 3 to 60 times. The upper limit of the draw ratio is about 70 times, and if the draw ratio is 70 times or more, it becomes difficult to draw PP, and it is difficult to obtain a good multi-layer structure.

In the present invention, the water content of the EVOH composition layer, which is a constituent of the multi-layer structure during thermoforming, especially heat stretching, is not particularly limited, but is within 0.01-10%. And more preferably 0.01 to 5%. There is no particular limitation on the method of collecting scraps such as trims and defective containers generated during container molding. The scrap is crushed and, if it is hygroscopic, dried, and then dry blended with the raw material PP resin, the scraped material is pelletized and then dry blended with the raw material PP resin, and the crushed scrap and the raw material PP resin are mixed. There are methods such as blending into pellets. Regarding the blending ratio of the raw material PP and the scrap, the higher the scrap ratio, the more easily abnormalities such as uneven thickness, unevenness, cracks, and whitening occur during stretch forming. It is blended in a certain ratio. At this time, to improve the dispersibility, thermal stability and suppress the above abnormalities during container molding, maleic anhydride modified polyolefins,
It may be preferable to blend a plurality of metal soaps, hydrotalcite-based compounds and the like.

The thermoforming of the present invention thus obtained,
In particular, the heat-stretched, especially high-speed heat-stretched multilayer structure does not show pinholes, cracks, or uneven thickness in the EVOH composition layer, so it has a very good gas barrier property and is a very good container for tableware packaging with little variation. Alternatively, it is effective for a container or the like that requires aroma retention. The present invention will be further described with reference to examples below, but the present invention is not limited thereto.

[0029]

Example 1 EVOH having an ethylene content of 50 mol%, a saponification degree of 99.4 mol%, a melt index (MI) (190 ° C.) of 160 g / 10 min
Vibron (A) (Measured frequency by Toyo Boardwin
Dynamic viscoelasticity E '(A) (140 ℃) 10 ⁸ dyn
It was e / cm ² . On the other hand, ethylene content 32 mol%, saponification degree 99.6 mol%, melt index (MI 190 ℃)
Dynamic viscoelasticity E '(B) of EVOH (B) of 1.5g / 10min
(150 ° C.) was 3 × 10 ⁹ dyne / cm ² . EVOH
(A) and EVOH (B) were mixed in a weight ratio of A / B = 20/80, and a twin screw type vent type 40φ extruder was used for N
₂ and extruded at 200 ° C. for pelletization. The obtained pellet was dried at 80 ° C. for 8 hours. The pellets were applied to a feedblock type 3 layer 5 layer coextrusion device to prepare a sheet. The sheet is composed of both outermost polypropylene layers (Mitsubishi Noblen MA-6) of 800μ or adhesive resin layers (Mitsubishi Petrochemical Modic P-300F; maleic anhydride modified polypropylene) of 50μ, and the innermost layer (center) is EVOH above. The layer is 50μ. This pellet is DSC
When measured at (scanning speed 10 ° C./min), endothermic peaks were found at two points (150 ° C., 183 ° C.). The resulting sheet was pulled at 150 ° C with tensile tension (pulling speed 5
0 mm / min, chuck interval 50 mm), 100%
The tension of the polypropylene layer at the time of elongation was 1.0 kg / 15 mm width. The tension of the EVOH single layer (50 μ) under the same conditions was 0.2 kg / 15 mm width. That is, EVO
The tensile tension ratio of the H layer / polypropylene layer was 0.2. The sheet was placed in a vacuum pressure air forming machine (drawing speed 9 × 10
Thermoforming (SPPF molding) was performed at 150% at ⁵ % / min, a drawing ratio of 1 and a drawing area ratio of 7 times. 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. and 65% RH was measured using a Model 10/50 manufactured by Mocon Co., and the oxygen permeation amount was 0.7 cc.
・ 20 μ / m ² · 24 hr · atm, which not only shows very good gas barrier properties, but also oxygen when measuring 10 samples
Variation in transmission amount (R = maximum value-minimum value) is 0.1 cc ・ 2
It was a very good barrier container with a very small value of 0 μ / m ² · 24 hr · atm.

Comparative Example 1 The procedure of Example 1 was repeated except that the EVOH (A) / EVOH (B) blend ratio was changed to 4/94 weight ratio. As a result, there were many cracks and uneven thicknesses, and the gas barrier property was 5 cc · 20 μ / m ² · 24 hr · atm, which was too great for use.

Comparative Example 2 A single EVOH having the same ethylene content as the average ethylene content (36 mol%) of the blend (20/80) of EVOH (A) and EVOH (B) in Example 1. (D
SC single peak, MI 190 ° C. 4.0 g / 10 min, dynamic viscoelasticity E′3 × 10 ⁸ dyne / cm ² ) and the same procedure as in Example 1. As a result, there were many cracks and uneven thicknesses, and they could not be used.

Example 2 EVOH having an ethylene content of 47 mol%, a saponification degree of 99.4 mol% and a melt index (MI190 ° C.) of 10 g / 10 min.
Dynamic viscoelasticity E '(A) (180 ° C) of (A) is 10 ⁸ dyne / c
It was less than m ² . On the other hand, ethylene content 27 mol%, saponification degree 99.6 mol%, melt index (190 ° C) 1.3 g /
10 minutes {(MI 210 ℃) 2.8g / 10 minutes; (MI 230 ℃) 5.5
The value obtained by extrapolating from g / 10 min} of the dynamic viscoelasticity E ′ (B) (190 ° C.) of EVOH (B) was 10 ⁹ dyne / cm ² . EVOH (A) and EVOH (B) are A / B = 10 /
80 weight ratio was added, and pelletization and sheet formation were carried out in the same manner as in Example 1. When this pellet was measured by DSC (scanning speed 10 ° C./minute), endothermic peaks were found at two points (198 ° C. and 175 ° C.). When the tensile tension of the obtained sheet at 190 ° C. was measured, the tension of the polypropylene layer at 100% elongation was 0.2 kg / 15 mm width,
The tension of EVOH single layer (50μ) under the same condition is 0.1kg.
/ 15 mm width or less. That is, the tensile tension ratio of the EVOH layer / polypropylene layer was 0.5. The sheet was vacuum-compressed and air-molded (stretching speed 6 × 10 ⁸ %, drawing ratio 1.8,
Thermoforming was performed at 190 ° C. using a stretching area ratio of 12 times. The obtained molded product was good in appearance without cracks, unevenness, and uneven thickness. In addition, the gas barrier property of this container has an oxygen permeation amount of 0.4 cc · 20 μ / m ² · 24 hr · atm (20
℃, 65% RH) is good, when 10 samples are measured
Variation in oxygen permeation amount (R) is 0.1 cc · 20 μ / m ² · 24
It was a very good gas barrier container with a very small hr · atm.

Comparative Example 3 In Example 2, EVOH (A) was used in an ethylene content of 47 mol%, a saponification degree of 99.4 mol%, and a melt index (MI).
190 ° C) 60 g / 10 minutes {MI (A) / MI (B) = 46.
2}, EV with dynamic viscoelasticity E '(A) 10 ⁸ dyne / cm ² or less
It changed into OH and it carried out like Example 2. as a result,
A large number of small uneven thicknesses were found in the molded container, and it could not be used in appearance.

Comparative Example 4 EVOH (B) in Example 1 was mixed with ethylene content of 42 mol%, saponification degree of 99.6 mol% and melt index (190
℃) 20g / 10min, dynamic viscoelasticity E '(B) 1 × 10 ⁹ dyne /
The same procedure as in Example 1 was carried out in place of cm ² of EVOH (B). As a result, slight unevenness (uneven thickness) was recognized in the molding container, and the variation (R) of the measured value of the oxygen permeation amount was also found.
It was 1.2 cc · 20 μ / m ² · 24 hr · atm and could not be used.

Example 3 The same procedure as in Example 1 was carried out by using the polypropylene containing the recovered product obtained by crushing the trim and the defective container after thermoforming in Example 1 and blending the polypropylene (MA-6) with 10% by weight. did. The appearance of the resulting molded product is good and the gas barrier property is such that the oxygen permeation amount is 0.7 cc · 20 μ / m ²
The variation (R) of the measured values of 24 hr · atm and oxygen permeation amount was 0.1 cc · 20 μ / m ² · 24 hr · atm, which was a very small barrier container.

Comparative Example 5 EVOH (A) in Example 1 was ethylene content 52 mol%, saponification degree 70 mol%, melt index (MI).
190 ° C) 15g / 10 minutes, changed to EVOH of E '(A) 5 × 10 ⁷ dyne / cm ² and EVOH (A) / EVOH
The mixing ratio of (B) was changed to 4/96, and the same procedure as in Example 1 was carried out. In the obtained molded product, a large number of spots were found in the EVOH layer, and a minute mark was found in the EVOH layer around the spot. As a result, the gas barrier property was as high as 23 cc · 20 μ / m ² · 24 hr · atm for oxygen transmission, and it could not be used.

Comparative Example 6 In place of 20 parts by weight of EVOH (A) in Example 1,
Tilene content 43 mol%, saponification degree 99.4%, MI 10 g /
10 minutes, E '(A) 2 × 10 ⁸ dyne / cm ² EVOH 50 weight
80 parts by weight of EVOH (B) and 50 parts by weight of EVOH (B).
The same procedure as in Example 1 was repeated except that the weight part was replaced. That
The gas barrier property of the resulting container has an oxygen transmission rate of 5.8.
cc · 20μ / m ² · 24hr · atm, bad, and oxygen permeability
The variation (R) of the measured value of the excess amount is also 1.0 cc ・ 20 μ / m ² ・
It was as large as 24 hr · atm. Also, local uneven thickness is generated on the container.
However, it was not preferable in appearance.

Comparative Example 7 In Example 1, 20 parts by weight of EVOH (A) was used instead of 20 parts by weight.
Ren content 70 mol%, saponification degree 99.5%, MI 30 g / 10
Min, E '(A) 5 × 10 ⁷ dyne / cm ² EVOH 30 parts by weight
Example 1 was repeated except that was used. That conclusion
As a result, a slight thickness unevenness (uneven thickness) was observed in the molded container,
The gas barrier property is that the oxygen permeation amount is 6.5 cc · 20 μ / m ² · 24
It was bad at hr.atm.

Comparative Example 8 The ethylene content as EVOH (A) in Example 1 was 72
Mol%, saponification degree 40%, MI 4g / 10 minutes, E '(A)
As Example 1 except that 10 ⁷ dyne / cm ² of EVOH was used.
The same was done. As a result, the molding container has unevenness (uneven thickness)
Is recognized, and the gas barrier property is an oxygen permeation amount of 12 cc · 20.
μ / m ² · 24 hr · atm
Constant value variation (R) is also 2.2cc ・ 20μ / m ² ・ 24hr ・
Atm was big.

Comparative Example 9 In Example 1, ethylene was used instead of EVOH (A).
Amount 60 mol%, Saponification degree 99.5%, MI 9g / 10min, E '
(A) Using 8 × 10 ⁷ dyne / cm ² of EVOH,
Instead of H (B), ethylene content 29 mol%, saponification degree 9
9.5%, MI 0.3g / 10min, E '(B) 4 × 10 ⁹ dyne /
The procedure was as in Example 1 except that cm ² of EVOH was used.
became. As a result, the molded container has cracks and pinholes.
Occurs, and the gas barrier property is an oxygen permeation amount of 8cc · 20μ.
/ M ² · 24 hr · atm, bad, and measurement of oxygen transmission rate
Variation in value (R) is also 1.9cc · 20μ / m ² · 24hr · a
It was as big as tm.

Comparative Example 10 Ethylene was used instead of EVOH (A) in Example 1.
Content 48 mol%, Saponification degree 99 mol%, MI 12 g / 10
Min, E '(A) 9 × 10 ⁷ dyne / cm ² EVOH is used
In place of EVOH (B), the ethylene content is 31 mol%,
Saponification degree 99%, MI 0.5g / 10 minutes, E '(B) 3 × 10 ⁹ dy
Same as Example 1 except that ne / cm ² EVOH was used.
Like that. As a result, there is unevenness (local deviation) in the molding container.
(Meat) is recognized, and the gas barrier property is an oxygen transmission amount of 9 cc.
・ 20μ / m ² ・ 24hr ・ atm, bad, and oxygen transmission rate
Variation of measured value (R) is also 2.0cc ・ 20μ / m ² ・ 24h
It was as large as r · atm.

Comparative Example 11 In Example 1, instead of EVOH (A), ethylene was used.
Content 46 mol%, degree of saponification 99.5%, MI 10 g / 10 minutes,
E '(A) (120 ° C) 5 × 10 ¹⁰ dyne / cm ² of EVOH
Use, instead of EVOH (B) ethylene content 30 mol
%, Saponification degree 99.5%, MI 1.5g / 10 minutes, E '(B)
(130 ° C) Using 6 × 10 ¹⁰ dyne / cm ² of EVOH,
In addition, instead of polypropylene (MA-6) ethylene-
Uses propylene copolymer (Mitsubishi Noblen Ex-6)
Then, the same procedure as in Example 1 was carried out except that thermoforming was performed at 130 ° C.
It was As a result, cracks and pinholes are generated in the molding container.
Oxygen permeation amount of 8.5cc ・ 20μ / m ²
・ 24 hr ・ atm, which is bad.
Ratsuki (R) is also 2.0cc · 20μ / m ² · 24hr · atm
It was great.

Comparative Example 12 In Comparative Example 11, ethylene was used instead of EVOH (B).
Content 30 mol%, saponification degree 98 mol%, MI 1.5 g / 10
Min, E '(B) (130 ℃) 4 × 10 ¹⁰ dyne / cm ² EVO
The procedure of Comparative Example 11 was repeated except that H was used. E '
(B) / E '(A) = 0.8. As a result,
There are cracks and pinholes on the vessel
(Local uneven thickness) occurs, and the gas barrier property is the amount of oxygen permeation.
9.5cc ・ 20μ / m ² ・ 24hr ・ atm, bad, and oxygen
The variation (R) of the measured transmission amount is also 1.8cc ・ 20μ / m ² ・
It was as large as 24 hr · atm.

[0044]

EFFECT OF THE INVENTION Thermoforming obtained by using the resin composition of the present invention
The product has few cracks and thickness unevenness, has extremely excellent gas barrier properties, and has little variation in gas barrier properties.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29K 96:00

Claims (2)

[Claims] 1. An ethylene-vinyl acetate copolymer saponification product (A) having an ethylene content of 45 to 60 mol% and a saponification degree of a vinyl acetate component of 96 mol% or more (A) of 6 to 70 wt% and an ethylene content of 1.
Saponification product of ethylene-vinyl acetate copolymer (B) having a viscosity of 25 to 40 mol% and a saponification degree of vinyl acetate component of 96 mol% or more (B) 94 to 30
And a polypropylene layer on at least one side of the resin composition layer having a plurality of endothermic peaks in melting curve by differential scanning calorimeter, and having the following formulas (I) to (III). A thermoformed product in which the tensile tension ratio of the resin composition layer to the polypropylene layer is 5 or less. 1 ≦ E ′ (B) / E ′ (A) …… (I) E ′ (A) ≦ 10 ⁹ dyne / cm ² …… (II) 0.05 ≦ MI (A) / MI (B) ≦ 20 …… (III) Dynamic viscoelasticity of E ′ (A) ... A at thermoforming temperature −10 ° C. Dynamic viscoelasticity of dyne / cm ² E ′ (B) ... B at thermoforming temperature dyne / cm ² MI (A) ・ ・ ・ A, melt index g under 190 ° C., 2160 g load g / 10 minutes MI (B) ・ ・ ・ B, melt index g / 190 ° C., under 2160 g load g / 10 minutes 2. The thermoformed product according to claim 1, which satisfies the following (I ′) to (III ′). 10 ≦ E ′ (B) / E ′ (A) …… (I ′) E ′ (A) ≦ 8 × 10 ⁸ dyne / cm ² …… (II ′) 0.06 ≦ MI (A) / MI (B) ≤18 …… (III´)