JPH06293119A - Polyamide laminated biaxially oriented film - Google Patents

Abstract

PURPOSE:To provide a film being excellent in oxygen gas barrier properties, bending pinhole resistance and toughness and suitable for soft packing of food, medicines or chemicals. CONSTITUTION:A polyamide laminated biaxially oriented film is composed of a structure containing at least two layers consisting of a mixture of an aromatic polyamide polymer and an ethylene/vinyl acetate copolymer and a mixture of an aliphatic polyamide polymer and the above mentioned mixture and has oxygen permeability of a specific value and bending pinhole resistance of a specific value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is excellent in oxygen gas barrier properties, bending pinhole resistance, toughness, etc., and is suitable for a film for packaging foods, medical products, chemicals, etc. which do not want to deteriorate the contents due to oxygen. The present invention relates to a polyamide-based laminated biaxially stretched film.

[0002]

2. Description of the Related Art Heretofore, unstretched films or stretched films of polyamide polymers have been used as various packaging materials, either alone or laminated with other films. However, the commonly used film made of an aliphatic polyamide polymer alone is excellent in mechanical properties such as tensile strength and bending pinhole resistance, but has a drawback that it is not sufficient in oxygen gas barrier property. . Therefore, in order to impart an oxygen gas barrier property to this film, a method of coating a vinylidene chloride polymer latex on the surface of the film to form a film having an excellent oxygen gas barrier property has been proposed and put into practical use. .

However, the film coated with this vinylidene chloride polymer latex has a drawback that it becomes cloudy when treated with hot water, and further, when it is incinerated, a compound containing chlorine is generated, which causes environmental pollution. It was also the cause. On the other hand, as a film having a good oxygen gas barrier property, an aromatic polyamide polymer containing a polyamide constitutional unit composed of m- and / or p-xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms as a main component is used. A raw material made from coalescence has been proposed. This film is
Although it is excellent in transparency and oil resistance, its use is limited because it is inferior in bending pinhole resistance.

In order to obtain a film having the advantages of both of the above polyamide-based polymers, that is, the tensile strength, flex pinhole resistance, and oxygen gas barrier property, the two polyamide-based polymers are used. A method for producing a laminated biaxially stretched film by an inflation method by separately melting and extruding the coalescence has been proposed (see JP-A-57-51427). Further, a laminated film having a structure in which a layer containing an aromatic polyamide polymer as a main component is sandwiched between layers containing an aliphatic polyamide polymer as a main component has also been proposed (JP-A-56-155762).
(See the official gazette).

However, in the laminated biaxially stretched film proposed in the above publication, for example, if the proportion of the aromatic polyamide polymer is increased in order to improve the oxygen gas barrier property, the flexural pinhole resistance of the laminated film is improved. descend. In addition, in order to improve bending pinhole resistance and toughness,
If the proportion of the aliphatic polyamide polymer is increased, the whole laminated film becomes thicker and cannot be used for flexible packaging, and neither the oxygen gas barrier property nor the flex pinhole resistance is at a satisfactory level.

[0006]

In view of the above situation, the present invention provides a polyamide laminated biaxially stretched film having excellent oxygen gas barrier properties, excellent flex pinhole resistance, toughness, and the like. The purpose is to

[0007]

Means for Solving the Problems The inventors of the present invention have completed the present invention as a result of extensive studies to solve the above problems. However, the gist of the present invention is that a polyamide structural unit consisting of m- and / or p-xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms is contained in the molecular chain in an amount of 70 mol% or more. Aromatic polyamide polymer (A) containing (a)
A layer, a layer (b) comprising an aliphatic polyamide polymer (B),
It has a structure containing at least two types of layers (c) consisting of the mixture (C) of the polymer (A) and the polymer (B), and the content of the vinyl acetate component is from 3% by weight to 20% by weight.
The following ethylene-vinyl acetate copolymer is mixed in the layer (a) in an amount of 0.3 to 5% by weight and in the layer (c) in an amount of 5% by weight or less, respectively, and the temperature is 25 ° C. and the relative humidity is 65%. Oxygen permeability under conditions of 15cc / m ² · 24H · at
Polyamide-based laminate 2 characterized in that the number of pinholes after bending 3000 times by Gelvo Flex Tester is 15/77 inch ² or less under conditions of m or less and temperature of 23 ° C. and relative humidity of 50% It exists in an axially stretched film.

The present invention will be described in detail below. The main raw materials for the polyamide-based laminated biaxially stretched film according to the present invention are two types of polyamide-based polymers and ethylene-vinyl acetate copolymer. One type of polyamide-based polymer is m-
And / or p-xylylenediamine and 6 to 1 carbon atoms
It is a polymer (hereinafter referred to as "polymer (A)") containing 70 mol% or more in the molecular chain of the polyamide constitutional unit consisting of the α, ω aliphatic dicarboxylic acid of 2.

Specific examples of the polymer (A) include polymeta-xylylene adipamide, poly-meta-xylylene pimeramide, poly-meta-xylylene-azeramide, poly-para-xylylene-azeramide and poly-para-xylylene-decanamide. Homopolymer, meta-xylylene / para-xylylene adipamide copolymer, meta-xylylene / para-xylylene pimeramide copolymer, meta-xylylene / para-xylylene azelamide copolymer, meta-xylylene / para-xylylene sepacamide copolymer Copolymers such as coalesced.

In addition, 70 mol% or more of polyamide constituent units consisting of m- or / and p-xylylenediamine and α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms are contained in the molecular chain. And a copolymer composed of other polyamide constituent components. Other polyamide constituent components include diamine components, dicarboxylic acid components and other components. Specific examples of the diamine component include
There are aliphatic diamines such as hexamethylenediamine and 2,2,4-trimethylhexamethylenediamine, diamines containing heterocyclic rings or heteroatoms such as piperazine bispropylamine and neopentyl glycol bispropylamine, and dicarboxylic acids. Specific examples of the acid component include aliphatic dicarboxylic acids such as adipic acid, azelaic acid and sebacic acid, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and cyclic fatty acids such as 1,4-cyclohexanedigalbonic acid. Other components include lactams such as ε-caprolactam and ω-aminocarboxylic acids such as ε-aminocarboxylic acid.

The polymer (A) may contain a polymer (D) compatible with the polymer (A) up to a range of 20% by weight. Examples of the polymer (D) that is compatible with the polymer (A) include polyamide polymers and other thermoplastic resins not exemplified above. The polymer (A) must have a polyamide constituent unit consisting of m- or / and p-xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain in an amount of 70 mol% or more. . Outside this range, the oxygen permeability to be imparted to the finally obtained laminated biaxially stretched film cannot reach 15 cc / m ² · 24H · atm or less under the conditions of temperature 25 ° C and relative humidity 65%. , Not preferable. Further, when the amount of the polymer (D) when the polymer (D) is contained in the polymer (A) exceeds 20% by weight, it is not preferable for the same reason.

Another type of polyamide polymer is an aliphatic polyamide polymer (hereinafter referred to as "polymer (B)"). The polymer (B) may be a chain polyamide having an amide bond, and specific examples thereof include homopolymer of ε-caprolactam, polyhexamethylene adipamide, and ε-caprolactam or hexamethylene. Examples thereof include a copolymer mainly composed of adipamide and 2 to 10 mol% of a compound copolymerizable therewith.

Examples of compounds copolymerizable with ε-caprolactam or hexamethylene adipamide include nylon salts of aliphatic diamines and aliphatic dicarboxylic acids. Specific examples of the aliphatic diamines include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine and the like. Specific examples of the aliphatic dicarboxylic acids include adipic acid, sebacic acid, cork acid, glutaric acid, azelaic acid, β-methyladipic acid, decamethylenedicarboxylic acid, dodecamethylenedicarboxylic acid, pimelic acid and the like.

Among these polymers (B), polyhexamethylene adipamide called nylon 6 or nylon 66, which is a homopolymer of ε-caprolactam, is
It is preferable because it can be obtained at low cost and the biaxial stretching operation can be smoothly performed. The mixture (C) is a mixture of the polymer (A) and the polymer (B), but may be a mixture of virgins, or the polyamide-based laminated biaxially stretched film of the present invention. It may be a nonstandard film produced at the time of manufacturing, or a scrap mixture such as a cut end material (edge trim) of the film side end, or a scrap mixture to which virgin is added. The mixing ratio of these two kinds of polymers is not particularly limited, but it is preferable to select the polymer (A) and the polymer (B) in a weight ratio of 7: 3 to 1: 9. .

The polymers (A), (B) and the mixture (C) of the polyamide-based polymers all have high hygroscopicity, and if they absorb moisture, when the raw materials are heat-melted and extruded, Since water vapor and oligomers are generated and inhibit film formation, it is preferable to dry in advance so that the water content is 0.1% by weight or less. Various additives such as a lubricant, an antistatic agent, an antioxidant, an antiblocking agent, a stabilizer, a dye, a pigment, and inorganic fine particles are added to these polyamide polymers within a range that does not affect the properties of the film. can do.

The ethylene-vinyl acetate copolymer as a main raw material has a vinyl acetate component content of 3% by weight or more.
It is an ethylene-vinyl acetate copolymer having a content of 0% by weight or less. When the content of the vinyl acetate component is less than 3% by weight, the dispersibility in the polyamide polymer is deteriorated, which may cause poor dispersion, which is not preferable. On the other hand, when it exceeds 20% by weight, the polymer melted during extrusion may be clogged in the filter in the melt pipe, which is not preferable because continuous production for a long time cannot be performed.

In order to disperse the ethylene-vinyl acetate copolymer in the polyamide polymer more uniformly, a suitable compatibilizer may be used in combination. When a compatibilizer is used in combination, it is desirable to mix it with an ethylene-vinyl acetate copolymer in advance and pelletize it, but if the dispersibility in the polyamide polymer does not change, it is not limited to this. Not something.

The three types of layers constituting the polyamide-based laminated biaxially stretched film according to the present invention are a layer (a) in which an ethylene-vinyl acetate copolymer is mixed with the polymer (A), and a polymer (B). (B) layer, and mixture (C) is mixed with ethylene-vinyl acetate copolymer (c) layer. The layer structure of the polyamide-based laminated biaxially stretched film of the product is such that at least two types of layers are contained by appropriately selecting and combining the layers (a), (b), and (c), and the number of layers is three. It is preferable to select in the range of 5 to 5 layers. Specific examples of the combination of layers and the number of layers in this case include (a) /
(B) / (c), (b) / (a) / (c), (b) /
(C) / (a), (b) / (a) / (b), (c) /
(A) / (c), (b) / (c) / (a) / (b),
(B) / (c) / (a) / (c) / (b), (b) /
(A) / (c) / (a) / (b), (c) / (b) /
Examples thereof include (a) / (b) / (c), but are not limited thereto.

In this case, the mixing ratio of the ethylene-vinyl acetate copolymer contained in the layer (a) is in the range of 0.3 to 5% by weight based on the total amount of all the polymers contained in the layer (a). If it is less than 0.3% by weight, there is no effect of improving the bending pinhole resistance of the obtained film, while it is 5% by weight.
If it exceeds, the obtained film becomes hazy, which is not preferable. Particularly preferable in the above range is 0.5 to 4% by weight. In addition, the layer (c) contains an ethylene-vinyl acetate copolymer since the ear trim and the like contain an ethylene-vinyl acetate copolymer when an ear trim or the like produced during the production of a laminated film is used. Although it may not be added in some cases, it may be newly added when the amount of the ethylene-vinyl acetate copolymer contained in the layer (c) is adjusted. The mixing ratio of the ethylene-vinyl acetate copolymer contained in the layer (c) is 5% by weight or less based on the total amount of all the polymers contained in the layer (c). The resulting film becomes hazy and is not preferable. Particularly preferred in the above range is 0.1 to 3% by weight.

In order to mix the polymer (A) constituting the layer (a) and the ethylene-vinyl acetate copolymer, the pellets of each polymer are uniformly dry-blended so as to have the above mixing ratio. Any of a method, a method of melting a dry blended product with an extruder and pelletizing the product may be used. The polyamide-based laminated biaxially stretched film according to the present invention can be manufactured by a conventionally known general method. First, a raw material comprising a polymer (A) mixed with an ethylene-vinyl acetate copolymer, a polymer (B) not mixed with an ethylene-vinyl acetate copolymer, and a mixture (C) mixed with an ethylene-vinyl acetate copolymer , Producing a substantially amorphous, non-oriented, unstretched laminated film.

This unstretched laminated film does not require an adhesive for adhering single films to each other, and it is preferable to adopt a co-extrusion method capable of obtaining a laminated film having excellent performance.
In the production method by the co-extrusion method, the above raw materials are melted by two or three extruders, extruded from a flat die or an annular die, and then rapidly cooled to obtain a flat or annular unstretched laminated film.

Next, the above-mentioned unstretched laminated film is biaxially stretched 2.5 to 5 times in the film flow (vertical axis) direction and in the direction (horizontal axis) perpendicular thereto. When the draw ratio is less than 2.5 times in the longitudinal direction and the transverse direction of the film, there is no effect of drawing, the strength of the film is poor, and when the draw ratio is greater than 5 times in each axial direction, The film is easily torn during stretching, which is not preferable. As the biaxial stretching method, a conventionally known stretching method such as tenter type sequential biaxial stretching, tenter type simultaneous biaxial stretching, tubular type simultaneous biaxial stretching, etc. can be adopted as long as it does not exceed the gist of the present invention.

For example, in the case of the tenter type sequential biaxial stretching method, the unstretched laminated film is heated to a temperature range of 50 to 110 ° C., and the roll type longitudinal stretching machine makes it 2.5 to 5 times in the longitudinal direction. Stretching is carried out, and subsequently, by a tenter type horizontal stretching machine within a temperature range of 60 to 120 ° C., a transverse direction of 2.5 to
It can be produced by stretching it 5 times. On the other hand, in the case of the tenter simultaneous biaxial stretching method or the tubular simultaneous biaxial stretching method, for example, 60 to 110 ° C.
2.5 to 5 in each axial direction in the temperature range of
It can be produced by stretching twice.

The film stretched by the above method is then heat treated. By performing heat treatment, a stretched film having excellent dimensional stability can be obtained. The heat treatment temperature is selected such that the lower limit is 110 ° C. and the upper limit is 5 ° C. lower than the melting point of the polymer (B).
In addition to a stretched film having excellent dimensional stability, a stretched film having an arbitrary heat shrinkage rate can be obtained.

The laminated biaxially stretched film, which is sufficiently heat-set by the heat treatment operation, is cooled by a conventional method and wound into a roll. The polyamide-based laminated biaxially stretched film according to the present invention has an oxygen permeability of 15 cc / m ² · 24 H · atm or less under the conditions of a temperature of 25 ° C and a relative humidity of 65%, and a temperature of 23 ° C and a relative humidity of 50%. Number of pinholes after bending 3000 times by Gelvo Flex Tester under
It is necessary that the number is 5/77 inch ² or less. The measured value of oxygen permeability in the present invention is measured under the conditions of a temperature of 25 ° C. and a relative humidity of 65% using an OXY-TRAN100 type oxygen permeability measuring device manufactured by Modern Control Co. In addition, the measurement value of the number of pinholes after being bent 3000 times by the Gelbo Flex Tester is that a film cut into a size of 8 inches × 11 inches is kept at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours or more. Let it stand and condition it, Gelbo flex tester (Rigaku Kogyo Co., Ltd., No. 901 type) (MIL-B-13
The bending test was repeated as follows, and the number of pinholes was measured.

The rectangular test film is wound into a cylindrical shape having a length of 8 inches, one end of the wound cylindrical film is on the outer circumference of the disk-shaped fixed head of the tester, and the other end is the disk-shaped of the tester. The movable head is fixed to the outer periphery of the movable head, and the movable head is parallel to the direction of the fixed head along the axis of both heads (the fixed head and the movable head face each other at a distance of 7 inches). Rotate 440 ° while approaching for 0.5 inch, then straight forward for 2.5 inch without rotating, and then reverse these operations to return the movable head to the initial position. A bending test of one cycle was continuously performed at a speed of 40 cycles per minute for 3000 cycles, and then fixed to the outer periphery of the fixed head and the movable head of the tested film. The pin number of holes generated in a portion of the 7 inches × 11 inches excluding the amount is a measure.

The total thickness of the polyamide-based laminated biaxially stretched film according to the present invention is preferably 10 μm or more and 40 μm or less. When the total thickness is less than 10 μm, the oxygen gas barrier property and the bending pinhole resistance are poorly balanced, and the abrasion resistance is also poor, so that a satisfactory film for packaging cannot be obtained. On the other hand, when the thickness exceeds 40 μm, the film becomes hard, and when the sealant layer is further laminated, the entire film becomes very thick, which is not suitable for soft packaging.

[0028]

EXAMPLES The contents and effects of the present invention will be described below in more detail with reference to Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples, the film was evaluated by each of the following methods. Table 1 shows the layer structure of the film and the evaluation results. <Oxygen permeability (cc / m ² · 24H · atm)> It was measured under the conditions of a temperature of 25 ° C and a relative humidity of 65% using an OXY-TRAN100 type oxygen permeability measuring device manufactured by Modern Control Co. <Bending resistance to pinholes (pieces / 77 inch ² )> A film cut into a size of 8 inches x 11 inches was used for gelbo flex tester (manufactured by Rigaku Kogyo, No. 901).
Type) (according to the standard of MIL-B-131C) was used and measured under the above-mentioned conditions.

Example 1 Polymethaxylylene adipamide (MXD-nylon 6121 manufactured by Mitsubishi Gas Chemical Co., Inc.) (polymer (A)) and an ethylene-vinyl acetate copolymer having a vinyl acetate component content of 11% by weight. Polymer (Mitsubishi Petrochemical Co., Ltd., Mitsubishi Polyethylene-EVA25K) mixed at a ratio of 97: 3, poly-ε-caproamide (Mitsubishi Kasei Co., Ltd., Novamid 1022) (polymer ( B)), and the trimmed end material of the film (the mixing ratio of the polymer (A) and the polymer (B) is 40:60, and the mixing ratio of the ethylene-vinyl acetate copolymer in the total polymer is 1). .2% by weight) are separately melted using three 65 mmφ extruders, laminated in a co-extrusion T-die to be extruded as a laminated film having a three-layer structure, and rapidly cooled by adhesion to a cast roll at 30 ° C. Then Outer layer is about 54 μm polymer (B), middle layer is about 36
A laminated unstretched film made of a mixture of the polymer (A) and ethylene-vinyl acetate copolymer having a thickness of μm, a polymer (A) having an inner layer of about 45 μm, and a mixture of the polymer (B) and an ethylene-vinyl acetate copolymer. Got

The laminated unstretched film thus obtained was stretched 3 times in the longitudinal direction with a roll-type stretching machine at 60 ° C.,
Then, the end portion of this film was held by a tenter clip, stretched in the tenter oven at 90 ° C. in the transverse axis direction by 3 times, and then heat-treated at 205 ° C. for 6 seconds. After heat treatment, the film grips with clips and cut off both ears of the film to make scrap. The product film is wound on a winder, and the polymer (B) layer ((b) layer) of about 6 μm, about 4 μm Of a mixture of the polymer (A) and ethylene-vinyl acetate copolymer ((a)
Layer), a polymer (B) of about 5 μm, and a layer of the mixture of the polymer (A) and an ethylene-vinyl acetate copolymer (layer (c)) are laminated in this order, and the total thickness of the layer is about 15 μm. A system laminated biaxially stretched film was obtained.

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance of the obtained film by the above-mentioned methods. Example 2 In the example described in Example 1, the ethylene-vinyl acetate copolymer was used as an ethylene-vinyl acetate copolymer having a vinyl acetate component content of 5% by weight (Mitsubishi Polyethylene Corporation, Mitsubishi Polyethylene). A polyamide-based laminated biaxially stretched film was obtained by the same method as described in the same example except that EVAV223H) was used instead.

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance by the above-mentioned methods for the obtained film. Example 3 In the example described in Example 1, the ethylene-vinyl acetate copolymer was used as an ethylene-vinyl acetate copolymer having a vinyl acetate component content of 20% by weight (manufactured by Mitsubishi Petrochemical Co., Ltd., Mitsubishi Polyethylene). A polyamide-based laminated biaxially stretched film was obtained by the same method as described in the same example except that EVAV501H) was used instead.

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance by the above-mentioned methods for the obtained film. Examples 4 to 9 In the examples described in Example 1, the layer constitution, the thickness of the film, the composition ratio of the raw materials, and the mixing ratio of the ethylene-vinyl acetate copolymer were changed as shown in Table 1, respectively. A polyamide-based laminated biaxially stretched film was obtained by the same method as described in the same example.

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance of the obtained film by the methods described above. Comparative Example 1 A polyamide laminated biaxially stretched film was obtained by the same method as described in Example 1 except that the ethylene-vinyl acetate copolymer was not used in the example described in Example 1.

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance of the obtained film by the methods described above. Comparative Example 2 In the example described in Example 1, the ethylene-vinyl acetate copolymer was changed to an ethylene-vinyl acetate copolymer having a vinyl acetate content of 2% by weight (Mitsubishi Polyethylene EVA V103H, manufactured by Mitsubishi Petrochemical Co., Ltd.). Other than the above, an attempt was made to prepare a polyamide-based laminated biaxially stretched film by the same method as described in the same example, but gel was generated due to poor dispersion of the ethylene-vinyl acetate copolymer, and stretching was not stable. No good product was obtained.

Comparative Example 3 In the example described in Example 1, the ethylene-vinyl acetate copolymer was used as an ethylene-vinyl acetate copolymer (manufactured by Mitsubishi Petrochemical Co., Ltd.) having a vinyl acetate component content of 33% by weight. Mitsubishi Polyethylene EVA X700) was used, and a polyamide-based laminated biaxially stretched film was tried to be produced by the same method as described in the same example, but a filter (absolute dust precision 20 μm) put in the melt pipe was used. I got clogged,
No product was obtained.

Comparative Example 4 Commercially available vinylidene chloride-coated biaxially stretched nylon film (manufactured by Mitsubishi Kasei Co., Santonir S)
Table 1 shows the results of measuring the oxygen gas barrier property and the bending pinhole resistance by the method described above using G, thickness 17 μm).

[0038]

[Table 1]

In Table 1, each abbreviation has the following meaning. A: Polymer (A) B: Polymer (B) EVA: Ethylene-vinyl acetate copolymer K-ONY: Vinylidene chloride coated biaxially stretched nylon film From Table 1, the polyamide-based laminated biaxially stretched film according to the present invention. Indicates that the measured values of oxygen gas barrier property, bending pinhole resistance, etc. are within the numerical values defined in the claims, and in particular, the bending pinhole resistance is excellent. Regarding the film of the comparative example, it is understood that the oxygen gas barrier property is within the numerical values defined in the claims, but the bending pinhole resistance value is outside the claims.

[0040]

EFFECT OF THE INVENTION Since the polyamide-based laminated biaxially stretched film according to the present invention has excellent oxygen gas barrier properties, excellent bending pinhole resistance, toughness, etc.,
It has a particularly remarkable effect that it is suitable for a packaging film for foods, medical products, medicines, etc. that do not like the deterioration of the contents due to oxygen, and its industrial utility value is extremely large.

[Procedure amendment]

[Submission date] March 15, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

Example 1 Polymethaxylylene adipamide (MXD-nylon 6121 manufactured by Mitsubishi Gas Chemical Co., Inc.) (polymer (A)) and an ethylene-vinyl acetate copolymer having a vinyl acetate component content of 5 % by weight Polymer (Mitsubishi Oil Chemical Co., Ltd., Mitsubishi Polyethylene
EVA V223H ) and a polymer obtained by mixing them at a ratio of 97: 3, poly-ε-caproamide (manufactured by Mitsubishi Kasei Co., Ltd.,
Novamid 1022) (polymer (B)), and film trim pieces of the ear trim of the film (polymer (A) and polymer (B))
And the mixing ratio of ethylene-vinyl acetate copolymer in the total polymer is 40:60, and the mixing ratio of ethylene-vinyl acetate copolymer is 1.2% by weight) is separately melted by using three 65 mmφ extruders. The film was laminated in an extrusion T-die and extruded as a laminated film having a three-layer structure, and was rapidly adhered to a cast roll at 30 ° C. and rapidly cooled.
A laminated unstretched film made of a mixture of the polymer (A) and ethylene-vinyl acetate copolymer having a thickness of μm, a polymer (A) having an inner layer of about 45 μm, and a mixture of the polymer (B) and an ethylene-vinyl acetate copolymer. Got

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance of the obtained film by the above-mentioned methods.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Example 2 In the example described in Example 1, an ethylene-vinyl acetate copolymer having an ethylene-vinyl acetate content of 20% by weight (manufactured by Mitsubishi Petrochemical Co., Ltd., A polyamide-based laminated biaxially stretched film was obtained by the same method as described in the same example except that it was replaced with Mitsubishi Polyethylene-EVAV501H).

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

Table 1 shows the results of measuring the layer structure of the film, the oxygen transmission rate, and the bending pinhole resistance by the above-mentioned methods for the obtained film. Examples 3 to 5 In the examples described in Example 1, except that the layer constitution, the thickness of the film, the composition ratio of the raw materials, and the mixing ratio of the ethylene-vinyl acetate copolymer were changed as shown in Table 1, respectively. A polyamide-based laminated biaxially stretched film was obtained by the same method as described in the same example.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

[0038]

[Table 1]

Claims (1)

[Claims] 1. An aromatic polyamide polymer containing, in its molecular chain, 70% by mole or more of a polyamide constitutional unit composed of m- and / or p-xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms. Composed of (A) (a)
A layer, a layer (b) comprising an aliphatic polyamide polymer (B),
It has a structure containing at least two types of layers (c) consisting of the mixture (C) of the polymer (A) and the polymer (B), and the content of the vinyl acetate component is from 3% by weight to 20% by weight.
The following ethylene-vinyl acetate copolymer is mixed in the layer (a) in an amount of 0.3 to 5% by weight and in the layer (c) in an amount of 5% by weight or less, respectively, and the temperature is 25 ° C. and the relative humidity is 65%. Oxygen permeability under conditions of 15cc / m ² · 24H · at
Polyamide-based laminate 2 characterized in that the number of pinholes after bending 3000 times by Gelvo Flex Tester is 15/77 inch ² or less under conditions of m or less and temperature of 23 ° C. and relative humidity of 50% Axial stretched film.