JPH08311276A - Composition of saponified ethylene/vinyl acetate copolymer resin and multilayer structure using the same - Google Patents

Abstract

PURPOSE: To obtain an EVOH resin composition which, when used in a laminate thereof with a thermoplastic resin, e.g. polypropylene, is excellent in stretchability and gas-barrier properties; and to obtain a multilayer structure using the composition. CONSTITUTION: This composition is characterized by its fusion curve having an endothermic peak and obtained with a differential scanning calorimeter. The curve has a total area (total quantity of heat) of 45J/g or larger and an area (quantity of heat) corresponding to 150 deg.C and higher of 55J/g or smaller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) resin composition and a multi-layer structure using the same, and more specifically to a thermoplastic such as polypropylene. The present invention relates to an EVOH resin composition that is excellent in stretchability and gas barrier property when laminated with a resin, and a multilayer structure using the same.

[0002]

2. Description of the Related Art Generally, EVOH is excellent in transparency, antistatic property, oil resistance, solvent resistance, gas barrier property, and aroma retention, but on the other hand, EVOH is inferior in impact resistance. It is used by laminating it with a thermoplastic resin. However, when this multi-layer structure is stretched, there is a problem that breakage, pinholes, cracks, etc. occur in the EVOH layer during stretching, resulting in deterioration of appearance, transparency, and gas barrier property. Therefore, in order to improve the stretchability, E
Addition of various plasticizers to VOH (JP-A-53-88067, JP-A-59-20345) and blend of polyamide resin (JP-A-52-141785, JP-A-58-36412). ) Etc. have been proposed.

On the other hand, two or more different EVOHs
A resin composition formed by blending, for example, EVOH having an ethylene content of 45 to 60 mol% and ethylene content of 25 to
Blend with 40 mol% EVOH (JP-A-63-2)
No. 64656), an EVO having a saponification degree of 96 mol% or more.
A blend of H and EVOH having a saponification degree of less than 96 mol% (JP-A-63-230757) has also been proposed. Further, Japanese Patent Laid-Open No. 7-40516 describes that a specific EVOH specified on the basis of measurement by a differential calorimeter is excellent in hot stretch formability.

[0004]

However, in the techniques disclosed in JP-A-53-88067 and JP-A-59-20345, it is necessary to add a large amount of a plasticizer in order to sufficiently improve the stretching properties. Yes, this significantly reduces the gas barrier property. The techniques disclosed in JP-A-52-141785 and JP-A-58-36412 are not preferable because long-run processability remains a problem, a large number of gels are generated in the molded product, and coloring occurs. Regarding the technique disclosed in JP-A-63-264656, blends of EVOHs having greatly different ethylene contents have poor transparency and gas barrier properties.
No. 30757 discloses an EV having a low saponification degree.
Since OH is used, thermal stability is deteriorated and gel is generated.

Furthermore, in the technique disclosed in Japanese Patent Laid-Open No. 7-40516, at the time of stretching, first, the temperature is raised to 10 to 30 ° C. higher than the stretching temperature, and then heat is drawn to the stretching temperature for stretching, that is, crystallization of EVOH is taken into consideration. The stretchability (voids, cracks, unevenness) is improved, but the stretchability is such a stretch ratio as to be used in the production of containers from the examples of the publications, and the area ratio is 20 times. It is still unsatisfactory for applications requiring high stretching as described above, for example, stretched barrier film applications, and there is room for improvement in further stretchability. Therefore, when it is used for lamination with a thermoplastic resin such as polypropylene, it has excellent transparency without impairing the excellent gas barrier property of EVOH, and has excellent stretchability without causing breakage, pinholes, cracks, stretching unevenness, or the like. Development of a good EVOH resin composition is desired.

[0006]

However, as a result of earnest studies to solve such a problem, the inventors of the present invention have found that in the melting curve showing an endothermic peak measured by a differential scanning calorimeter, the total area ( The present invention has been completed by finding that an EVOH resin composition having a total heat amount of 45 J / g or more and an area (heat amount) of 150 ° C. or more of 55 J / g or less can solve such problems. In the present invention, such EVO
When the H resin composition further contains at least one compound selected from a boron compound, a copper compound, an aluminum compound, a titanium compound and a zirconium compound, the effects of the present invention such as excellent stretchability and gas barrier property are particularly remarkable. Shown in. Regarding the measurement with the differential scanning calorimeter,
After heating up to 230 ° C at 10 ° C / min, 10 ° C / m
The total area and the area of 150 ° C. or higher are measured by determining the melting curve showing the endothermic peak when the temperature is lowered to 30 ° C. in and the temperature is raised again at 10 ° C./min.

More detailed description will be given with reference to FIG.
Is a melting curve of a typical example of the EVOH resin composition of the present invention (not limited to this), the starting point of the peak of the melting curve is a, the ending point of the peak is b, and 15
When a straight line is drawn on 0 ° C., a point intersecting the curves a to b is c, and a point intersecting the straight line ab is d, the total area in the present invention is the curves a to c and the straight line a. The area surrounded by −d−b (S ₁ + S ₂ ), and the area of 150 ° C. or higher is the area surrounded by the curves c to b, the straight line b−d, and the straight line c−d (S ₂ ). That is, in the present invention, the above area (S ₁ +
The heat quantity represented by S ₂ ) may be 45 J / g or more, and the heat quantity represented by the area (S ₂ ) may be 55 J / g or less.

The present invention will be described in detail below. The EVOH of the present invention has a total area (total calorific value) of 45 J / g or more, preferably 50 J / g or more, more preferably 53 in the melting curve showing the endothermic peak measured by the differential scanning calorimeter as described above. ~ 80 J / g and 150
Area (heat quantity) above ℃ is 55 J / g or less, preferably 5
EVOH may be 0 J / g or less, and in such a melting curve, if the total area (total calorific value) is less than 45 J / g, the oxygen barrier property becomes poor, and the area (calorific value) of 150 ° C. or higher exceeds 55 J / g. Therefore, the stretchability becomes insufficient and the effect of the present invention is not exhibited.

The method for obtaining the above specific EVOH resin composition is not particularly limited, and 100 parts by weight of EVOH is added to EVOH with a plasticizer having a high melting point, for example, polyalcohols having an alkyl chain having 2 to 20 carbon atoms. Against 1
-10 parts by weight, preferably 2-5 parts by weight,
A specific functional group such as a monocarboxylic acid compound, an epoxy compound or an amino compound is added to the EVOH in an amount of 0.1 to 10
Examples thereof include a method of grafting mol%, preferably 0.5 to 5 mol%, a method of blending two or more kinds of EVOH having different ethylene contents, and the like. Among them, the most simple method for obtaining the specific EVOH resin composition is to blend two or more kinds of EVOH having different ethylene contents, and the method will be described in detail below.

The EVOH used is not particularly limited, but in any case, the ethylene content is 20 to 60 mol%, preferably 25 to 50 mol%, more preferably 27 to 45.
It is desirable that the saponification degree is 96 mol% or more in mol%. If the ethylene content is less than 20 mol%, the gas barrier properties and melt moldability at high humidity will deteriorate, and if it exceeds 60 mol%, sufficient gas barrier properties cannot be obtained. If the saponification degree is less than 96 mol%, the gas barrier property, thermal stability and moisture resistance will be reduced.

The EVOH is obtained by saponification of an ethylene-vinyl acetate copolymer, and the ethylene-vinyl acetate copolymer can be obtained by any known polymerization method such as suspension polymerization,
It is produced by emulsion polymerization, solution polymerization and the like, and saponification of the ethylene-vinyl acetate copolymer can be performed by a known method. The EVOH is a small amount of α-olefin,
It may be "copolymer-modified" with other comonomers such as unsaturated carboxylic acid compounds, unsaturated sulfonic acid compounds, (meth) acrylonitrile, (meth) acrylamide, vinyl ether, vinyl chloride and styrene.
Further, “post-modification” such as urethanization, acetalization or cyanoethylation may be carried out within a range that does not impair the gist of the present invention.

In the present invention, it is only necessary to blend two or more kinds of EVOH arbitrarily selected from such EVOH, but it is particularly preferable to use two or more kinds of EVOH having different ethylene contents, In the blend, the difference in ethylene content between the EVOH (A) with the largest blending amount and the EVOH (B) with the next largest blending amount is 3 to 20.
Mol%, preferably 3 to 15 mol%, more preferably 5
It is preferably ˜15 mol%. If the difference in ethylene content is less than 3 mol%, the effect of the present invention will not be exhibited, and if it exceeds 20 mol%, the transparency will be poor and the film-forming stability will be poor, which is not preferable in practice. The difference in ethylene content is the ethylene content of EVOH (A) (a),
If the ethylene content of EVOH (B) is (b), |
(A)-(b) |

The blending amount of each EVOH to be blended is appropriately selected depending on the type of EVOH to be blended. The blending method is not particularly limited, and a method of dissolving each EVOH in a water-alcohol solvent and mixing, a method of dissolving each EVOH before saponification ethylene-vinyl acetate copolymer in an alcohol solvent such as methanol. Examples of the method include a method of mixing and saponifying in the above state, a method of melting and mixing each EVOH, and the like, but a method of melting and mixing is usually used.

For example, a method of dry blending each EVOH and then melting and blending, a method of blending each EVOH in a molten state, or a kind of EVO in a molten state
Examples thereof include a method of adding other EVOH to H in a dry state. Among them, the method of dry-blending each EVOH and then melting and blending them is practical in terms of the simplicity of the apparatus and the cost of the blended product.

Thus, according to the above-mentioned manufacturing method, in the melting curve showing the endothermic peak measured by the differential scanning calorimeter, the total area (total calorific value) is 45 J / g or more, and 15
EVO having an area (calorific value) of 0 ° C or higher of 55 J / g or less
H resin composition is obtained, and EVOH in the above range is obtained.
The effect of the present invention is exhibited only when the resin composition is prepared. In the present invention, by using the EVOH resin composition, a film or sheet excellent in stretchability and gas barrier property can be obtained. In particular, the EVOH resin composition may further contain a boron compound, a copper compound and aluminum. By containing at least one compound selected from a compound, a titanium compound, and a zirconium compound, the stretchability is further improved, the thickness accuracy during film formation is improved, no streaks occur, and there is no stretching unevenness during stretching. A film is obtained.

Among the boron compounds, copper compounds, aluminum compounds, titanium compounds and zirconium compounds used, boron compounds are preferably used because of their low toxicity when used as food packaging materials, and examples of the boron compound include boric acid and boronic acid. Examples thereof include acid salts, boric acid esters, borax, boron halides, trialkylborones, triarylborones and the like. The method of incorporating the above boron compound or the like into the EVOH resin composition is not particularly limited, but it is added at the same time when EVOH is blended, is added to at least one EVOH in advance, or is added after blending. Alternatively, the boron compound may be dissolved in a solvent such as water and mixed with EVOH, or the EVOH may be dipped in a solution of the boron compound. The content of the boron compound is 0.01 to 5% by weight, preferably 0.01 to 1% by weight, and more preferably 0.01 to 0.5% by weight, based on the total weight of EVOH in terms of boron. If less than 0.01% by weight, the effect of containing a boron compound cannot be obtained, while on the other hand, 5% by weight
If it exceeds the range, gel is generated probably because the boron compound is localized, which is not preferable.

Further, in the present invention, if necessary, a plasticizer,
It is also possible to use additives such as heat stabilizers, ultraviolet absorbers, antioxidants, colorants, fillers and other resins.
In particular, a hydrotalcite-based compound, a hindered phenol-based, a hindered amine-based heat stabilizer, or a metal salt of a higher aliphatic carboxylic acid can be added as a gel generation inhibitor.

The EVOH resin composition of the present invention thus obtained is frequently used for moldings, and is molded by melt-kneading into pellets, films, sheets, containers, fibers, rods, tubes, various molded products and the like. In many cases, these crushed products (such as when the collected products are reused) and pellets are used again for melt molding. As a melt molding method, an extrusion molding method (T-
Die extrusion, inflation extrusion, blow molding, melt spinning, profile extrusion, etc.) and injection molding methods are mainly adopted.
The melt molding temperature is often selected from the range of 200 to 250 ° C.

The EVOH resin composition obtained by the present invention is
It can be used for the molded article as described above, but especially the EV
It is preferable to use it as a multilayer structure in which a thermoplastic resin layer is laminated on at least one surface of a layer composed of an OH resin composition, and a multilayer structure suitable for practical use can be obtained. Since the multilayer structure uses the EVOH resin composition of the present invention, it exhibits not only excellent gas barrier properties and transparency but also excellent stretchability during high stretching.

In producing the multilayer structure, another substrate is laminated on one side or both sides of the layer of the resin composition obtained in the present invention. As a laminating method, for example, the resin composition is used. , A method of melt-extruding a thermoplastic resin into a film or a sheet, a method of melt-extruding the resin composition to a base material such as a thermoplastic resin, and a method of co-extruding the resin composition with another thermoplastic resin. Further, a method of laminating a film of the resin composition obtained in the present invention, a sheet and a film of another base material, a sheet with a known adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound, etc. Is mentioned.

In the case of coextrusion, the other resin is linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene. -Acrylic vinegar ester copolymer, polypropylene, propylene-α-olefin (having 4 to 20 carbon atoms)
.Alpha.-olefin) copolymers, homo- or copolymers of olefins such as polybutene and polypentene, or polyolefins in a broad sense such as those obtained by graft-modifying homo- or copolymers of these olefins with unsaturated carboxylic acids or their esters. Examples thereof include resin, polyester, polyamide, copolyamide, polyvinyl chloride, polyvinylidene chloride, acrylic resin, styrene resin, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene and chlorinated polypropylene. Saponified ethylene-vinyl acetate copolymers can also be coextruded. Among the above, polypropylene, polyamide, and polyethylene are preferably used from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength).

Further, a molded product such as a film or sheet is once obtained from the resin composition obtained in the present invention, and another substrate is extrusion coated thereon, or the film or sheet of the other substrate is bonded with an adhesive. When laminating using, any substrate (paper, metal foil, uniaxially or biaxially stretched plastic film or sheet, woven fabric, non-woven fabric, metallic cotton, wood, etc.) can be used in addition to the above thermoplastic resin. is there. The layer structure of the multi-layer structure is the same as the layer of the resin composition obtained in the present invention with a (a ₁ , a ₂ ,
...), another substrate such as a thermoplastic resin layer b
(B ₁ , b ₂ , ...) When a film, a sheet,
If it is a bottle, not only a / b two-layer structure but also b /
a / b, a / b / a, a 1 / a 2 / b, a / b 1 / b 2, b
Any combination such as ₂ / b ₁ / a / b ₁ / b ₂ is possible, and in the filament form, a and b are bimetal type, core (a) -sheath (b) type, core (b) -sheath (a ) Type or an eccentric core-sheath type.

In the case of co-extrusion, a may be blended with b, b may be blended with a, or at least one of a and b may be blended with a resin for improving the adhesiveness of both layers. In the present invention, the multilayer structure is used as it is in various shapes, but in order to further improve the physical properties of the multilayer structure, it is preferable to carry out a stretching treatment. Even when stretched 20 times or more, breakage, pinholes,
Since it has excellent stretchability without cracks and gas barrier properties and transparency, it is a structure excellent in thinning.

The stretching may be either uniaxial stretching or biaxial stretching, and it is better in terms of physical properties to perform stretching at the highest possible ratio. In the case of uniaxial stretching, it is 5 times or more, particularly 10 times or more, and in the case of biaxial stretching, the area ratio is 5 times or more.
It is preferable from the viewpoint of physical properties that the area ratio is 20 times or more, particularly 24 to 50 times. It is possible to obtain a stretched film, a stretched sheet, or the like that does not cause holes, cracks, or stretching unevenness.

Examples of the stretching method include a roll stretching method, a tenter stretching method, a tubular stretching method and a stretching blow method.
Of the deep drawing and vacuum forming, those having a high draw ratio can be used. In the case of biaxial stretching, either simultaneous biaxial stretching method or sequential biaxial stretching method can be adopted. Stretching temperature is 80
To 170 ° C., preferably about 100 to 160 ° C.

In the present invention, the EVOH of the present invention
By using a resin composition, that is, an EVOH resin composition having a specific amount of heat absorbed in melting EVOH,
For the first time, it was possible to stretch a multi-layer structure at a high magnification. After the stretching is completed in this way, heat setting is then performed.
The heat setting can be carried out by a known means, and the stretched film is heat-treated at 80 to 170 ° C., preferably 100 to 160 ° C. for about 2 to 600 seconds while keeping the stretched state.
Further, the obtained stretched film may be subjected to cooling treatment, rolling treatment, printing treatment, dry laminating treatment, solution or melt coating treatment, bag making processing, deep binding processing, box processing, tube processing, split processing, etc., if necessary. You can

The multilayer structure thus obtained may have any shape, and examples thereof include films, sheets, tapes, bottles, pipes, filaments, and modified cross-section extrudates. In addition, the resulting multilayer structure may, if necessary,
A heat treatment, a cooling treatment, a rolling treatment, a printing treatment, a dry laminating treatment, a solution or melt coating treatment, a bag making process, a deep tie process, a box process, a tube process, a split process and the like can be performed. The film, sheet or container obtained as described above is useful as various packaging materials for foods, pharmaceuticals, industrial chemicals, agricultural chemicals and the like.

[0028]

[Working] Since the EVOH resin composition of the present invention is composed of those exhibiting a specific melting curve measured by a differential scanning calorimeter, it has not only gas barrier property and transparency but also thermoplastic resin such as polypropylene. It is possible to obtain a film, sheet or the like having excellent stretchability that does not cause breakage, pinholes, cracks, stretch unevenness, etc.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "parts" and "%" are based on weight unless otherwise specified. Example 1 Production of EVOH Resin Composition EVOH (A) having an ethylene content of 45 mol% and a saponification degree of 97.0 mol% and EVOH (B having an ethylene content of 30 mol% and a saponification degree of 99.5 mol% ) Is mixed in a weight ratio of 6
The mixture was fed to a single-screw extruder at 0:40, melt-mixed at 220 ° C., pelletized, put into a 1% aqueous boric acid solution, and stirred at 80 ° C. for 12 hours,
Wash with pure water at 15 ℃, dry at 110 ℃ for 8 hours,
An EVOH resin composition of the present invention was obtained. The total area (total calorific value) of the melting curve showing the endothermic peak of the EVOH resin composition measured by a differential scanning calorimeter is 53 J / g, and the area (caloric value) at 150 ° C. or higher is 35 J / g. It was The differential scanning calorimeter is Perkin Elmer DSC7.
Was used.

Manufacture of Multi-layered Structure Using the above EVOH resin composition, the feed block 5
Layer T-die, polypropylene layer / adhesive resin layer / EV
A film was formed so as to have a layer structure of OH resin composition layer / adhesive resin layer / polypropylene layer to prepare a multilayer laminated film. The film composition is 100 μm for both outer polypropylene layers (polypropylene MI 1.2 g / 10 min).
The adhesive resin layer (the adhesive resin is maleic anhydride-modified polypropylene and its MI is 2.6 g / 10 min) has a thickness of 25 μm,
The EVOH resin composition layer of the intermediate layer has a thickness of 50 μm. For such a multilayer structure, stretchability, stretch unevenness, oxygen permeability,
Transparency was evaluated as follows.

(Stretchability) The above-mentioned multilayer structure was 8 cm × 8 c
m, sample was preheated at 150 ° C. for 1 minute, and stretched at 100 mm / sec at a stretching rate of 4 in the machine direction.
The film was sequentially biaxially stretched in the order of 6 times in the transverse direction and 6 times in the transverse direction (stretching ratio: 24 times), and the appearance change of the obtained stretched film was evaluated according to the following criteria. ◯: A smooth film is obtained even after stretching. X: The film is whitened or fibrillated after stretching.

(Stretching unevenness) In the stretched film obtained in the same manner as above, the appearance change was evaluated according to the following criteria. O: No streak was generated. Δ: 1-2 streaks were generated. X: Three or more streaks were generated.

(Oxygen Permeability) The oxygen permeability of the stretched film obtained in the same manner as described above was measured by MODERN-CONT.
20 using OX-TRAN10-50 manufactured by OROL
Measured under conditions of ℃ and 65% RH (cc / m ² · da
y • atm). (Transparency) Murakami Color Research Laboratory RM
The haze value of the stretched film obtained in the same manner as above was measured using -15A.

Examples 2 to 4 and Comparative Examples 1 to 5 EVOH was prepared according to Example 1 using EVOH shown in Table 1.
A resin composition was obtained. With respect to the EVOH resin composition, a multi-layer structure was prepared in the same manner as in Example 1 and each physical property was evaluated. For Example 3, EVOH (A) and E
In addition to VOH (B), as EVOH (C), Et:
45 mol% and Sv: 97.0 mol% were used, and the compounding ratio A /
Three kinds of EVOH so that B / C = 40/30/30
Was mixed. Table 2 shows the evaluation results of the examples and the comparative examples.

[0035]

[Table 1] EVOH (A) EVOH (B) Boron content Blending ratio Et Sv Et Sv (%) A / B Example 1 45 97.0 30 99.5 0.02 60/40 〃 2 40 99.5 45 97.0 0.03 70/30 〃 3 30 99.5 40 98.5 0.03 40/30 〃 4 40 99.5 45 97.0 0 70/30 Comparative Example 1 40 99.5 − − 0.02 − 〃 1 45 97.0 − − 0.02 − 〃 2 30 99.5 50 99.5 0.02 85/15 〃 3 32 99.5 44 99.5 0 50/50 〃 4 40 99.5 45 97.0 0.03 90/10

Note) Et: ethylene content (mol%) Sv: saponification degree (mol%) The boron content was determined by an atomic absorption method.

[0037]

[Table 2] Stretchability over 150 ° C over the entire area Stretching unevenness Oxygen permeability Transparency (total calorie) Area (calorie) (cc / m ² · day · atm) (J / g) (J / g) Example 1 53 35 ○ ○ 23 2.1 〃 2 66 48 ○ ○ 10 1.9 〃 3 59 40 ○ ○ 18 1.9 〃 4 66 48 ○ △ 30 2.1 Comparative Example 1 71 63 × -over 31.5 〃 236 14 ○ ○ 75 1.9 〃 3 7 7 766 × − over 42.3 〃 4 77 769 × − over 35.4 〃 5 7266 × − over 32.5 Note)-: Whitening of film, fibrillation, etc. As a result, the number of streaks could not be measured. over: The oxygen permeability could not be measured because it exceeded the measurable range of the measuring device.

[0038]

Since the EVOH resin composition of the present invention comprises a composition exhibiting a specific melting curve measured by a differential scanning calorimeter, it has not only gas barrier property and transparency but also thermoplasticity such as polypropylene. When it is used for lamination with a resin, it exhibits an excellent effect of stretchability without causing breakage, pinholes, cracks, stretch unevenness, and the like.

[Brief description of drawings]

FIG. 1 is a melting curve of a saponified ethylene-vinyl acetate copolymer resin composition of the present invention measured by a differential scanning calorimeter.

[Explanation of symbols]

a: the point at which the peak of the melting curve begins to rise b: the end of the peak of the melting curve c: when a straight line is drawn on 150 ° C, the point where it intersects curves a to b d: when a straight line is drawn on 150 ° C At a point intersecting the straight line a-b S ₁ : area surrounded by the curves a to c, the straight lines a to d and the straight line c d S ₂ : surrounded by the straight lines c to b, the straight line b d and the straight line c d area

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 14, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

In the case of coextrusion, the other resin is linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene. -Acrylic ester copolymer, polypropylene, propylene-α-olefin (having 4 to 20 carbon atoms)
Α-olefin) copolymer, polybutene, homopolymer or copolymer of olefin such as polypentene, or a polyolefin in a broad sense such as homo- or copolymer of these olefins graft-modified with unsaturated carboxylic acid or its ester Examples thereof include resins, polyesters, polyamides, copolyamides, polyvinyl chloride, polyvinylidene chloride, acrylic resins, styrene resins, vinyl ester resins, polyester elastomers, polyurethane elastomers, chlorinated polyethylene, and chlorinated polypropylene. Saponified ethylene-vinyl acetate copolymers can also be coextruded. Among the above, polypropylene, polyamide, and polyethylene are preferably used from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength).

Claims (7)

[Claims] 1. A melting curve showing an endothermic peak measured by a differential scanning calorimeter has a total area (total calorific value) of 45.
Area (heat quantity) of J / g or more and 150 ° C or more is 5
An ethylene-vinyl acetate copolymer saponified resin composition, which is 5 J / g or less. 2. The ethylene-vinyl acetate-based copolymerization product according to claim 1, further comprising at least one compound selected from a boron compound, a copper compound, an aluminum compound, a titanium compound and a zirconium compound. Combined saponified resin composition. 3. The ethylene-vinyl acetate copolymer saponifier according to claim 1, which is a blend of two or more kinds of saponified ethylene-vinyl acetate copolymers having different ethylene contents. Resin composition. 4. A difference in ethylene content between the saponified ethylene-vinyl acetate copolymer (A) having the largest content and the saponified ethylene-vinyl acetate copolymer (B) having the second largest content. Is 3 to 20 mol%, and the saponified ethylene-vinyl acetate copolymer resin composition according to claim 3. 5. The ethylene according to any one of claims 1 to 4.
A multilayer structure comprising a thermoplastic resin layer laminated on at least one side of a layer made of a saponified vinyl acetate copolymer resin composition. 6. The multilayer structure according to claim 5, which is stretched in at least a uniaxial direction. 7. The multilayer structure according to claim 5, wherein the thermoplastic resin is a polyolefin resin.