JPH08118570A - Coextrusion laminated film scarcely occurring with pinhole - Google Patents

Abstract

PURPOSE: To prevent the generation of pinhole even by repeated twisting by forming by four or more layers having a laminated structure of a layer made of polyamide resin, a layer of adhesive polymer, a layer of the same resin and a layer of the same polymer in a layer layout as seen from the outside. CONSTITUTION: A coextrusion laminated film in which a pinhole scarcely occurs and comprises four layers or more having a laminated structure of a layer A made of polyamide resin N1, a layer B made of adhesive polymer M1, a layer C of a polyamide resin N2, and a layer D of adhesive polymer M2. The thicknesses of the layers A, B, C and C are 5 to 60μm, 3 to 100μm, 5 to 60μm and 20 to 150μm, respectively. The sum of the layers A and C is 10 to 60% to the sum of the laminated film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a coextrusion laminating method in which pinholes are less likely to occur even after 1000 repeated twisting tests, as a convenient means for realizing rigor far exceeding various types of deformation expected in ordinary use. Regarding film. Specifically, the present invention is a layer of polyamide resin (N1) in the layer arrangement viewed from the outside (A) // layer of adhesive polymer (M1) (B) // layer of polyamide resin (N2) ( C) // Layer made of adhesive polymer (M2) (D)
The present invention relates to a co-extruded laminated film which is free from pinholes even when it is repeatedly twisted a large number of times and which has at least a laminated structure consisting of. More specifically, the present invention relates to a coextrusion laminated film in which a sealant resin layer is further laminated on the inside of the above laminated film, and pinholes are less likely to be generated even by repeated twisting many times.

The expression "pinholes are unlikely to occur" used in the present invention does not always mean that pinholes at the measurement level exist from the beginning, and the measurement level is reached only by the harsh treatment of "many repeated twists". It represents the original state that there are weaknesses that change into pinholes of a certain degree.

[0003]

2. Description of the Related Art Polyamide resin (N1) layer (A) // Adhesive polymer (M1) layer (B) // Sealant polymer (S) made of polyolefin in layer arrangement viewed from the outside Many laminated films composed of the layer (E) have already been used.
However, this laminated film is shown in Comparative Example 1 using a Gelbo flex tester, which is a stricter test than practical conditions in that there is a risk that a large number of pinholes will be left depending on the severe usage conditions encountered in practice.

An olefin resin is used as an improved laminated film which is less likely to cause pinholes than the conventional films described above.
(P1) layer (F) // adhesive olefin polymer (M1) layer (B)
// Layered film composed of polyamide resin (N2) layer (C) // adhesive polymer (M2) layer (D) // olefin resin (S) layer (F) Has been.

Although this laminated film is improved in pinhole resistance as compared with the laminated film mentioned at the beginning, it still has a problem that pinholes are generated by repeated twisting many times.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have extensively searched for various laminated films and their laminating methods in order to realize a high level of pinhole suppression which could not be realized by any of the laminated films described above. Finally, the present invention was completed. Moreover, the present inventor divides the polyamide resin layer into two or more layers while maintaining the overall layer thickness of the polyamide resin layer constituting the laminated film to be equal to the layer thickness of the single layer of polyamide resin in the conventional laminated film. Even if the layer thickness of each polyamide resin layer is greatly reduced by interposing another type of resin layer in the above, the number of pinholes generated was successfully reduced.

Although it seems to be similar to this, even if each of the divided polyamide resin layers is selected as a different type of polyamide resin, the number of pinholes is apt to be generated if another different polymer layer is not interposed therebetween. It is worth noting that it will not decrease. Furthermore, the present inventor has also found that the coextrusion laminating method is the most suitable method for forming the laminated film of the present invention. The reason is that the laminated film obtained by the conventional lamination method such as dry lamination becomes hard.

[0008]

Means for Solving the Problems The present inventor can achieve the above-mentioned object for the first time by the constitutions defined in the following "basic constitution of invention" and "improved constitution 1 of invention" to "improved constitution 7 of invention". Was successfully resolved.

[Basic Construction of the Invention] Layer (A) // adhesive polymer made of polyamide resin (N1) in a layer arrangement viewed from the outside
(M1) layer (B) // polyamide resin (N2) layer (C) // adhesive polymer (M2) layer (D) Co-extrusion laminated film that does not easily generate pinholes.

[Improved Structure 1 of the Invention] The layer thickness of the layer (A) made of the polyamide resin (N1) constituting the coextruded laminated film is 5 to 5.
60 μm, the layer thickness of the adhesive polymer (M1) layer (B) is 3 to 10
0 μm, the layer thickness of the polyamide resin (N2) layer (C) is 5 to 60
μm and the layer thickness of the adhesive polymer (M2) layer (D) is 20 to 15
The coextrusion laminated film according to the "basic constitution of the invention" having a thickness of 0 µm.

[Improved Structure 2 of the Invention] The sum of the layer thickness of the polyamide resin (N1) layer (A) and the polyamide resin (N2) layer (C) constituting the coextruded laminated film is The coextruded laminated film according to "Basic constitution of the invention" and "Improved constitution 1 of the invention", which is 10 to 60% of the total layer thickness of the laminated film.

[Improved Structure 3 of the Invention] The polyamide resin layers are the same or different kinds of polyamide resin (N1) and polyamide resin (N2), and each is selected from homopolymerized polyamide resin and copolymerized polyamide resin. The coextrusion laminated film described in "Basic Structure of the Invention" and "Improved Structure 1 of the Invention" and "Improved Structure 2 of the Invention", which is a layer formed of one or more polyamide resins.

[Improved Structure 4 of the Invention] Polyamide Resin (N1)
And the polyamide resin (N2) is one or more selected from the following homopolymerized polyamide resin group or a combination of two or more homopolymerized polyamide resins, or one or more selected from the following copolymerized polyamide resin group Alternatively, a "basic constitution of the invention" which is a combination of two or more kinds of copolyamide resins thereof or selected from the following cocondensates
And the coextruded laminated film described in "Improved constitution 1 of invention" to "improved constitution 3 of invention": (1) Homopolymerized polyamide resin: 6-polyamide, 7-polyamide, 11-polyamide and 12-polyamide; ) Copolymerized polyamide resin: 6,6-polyamide, 6,7-polyamide, 6,10-polyamide, 6,12-polyamide and metaxylylenediamine-adipic acid cocondensation polymer; (3) 6-polyamide and 6 Co-condensate with 6,6-polyamide and 6-
Co-condensate of polyamide and 12-polyamide.

[Improved Structure 5 of the Invention] The adhesive polymer (M1) and the adhesive polymer (M2) are adhesive polymers of the same kind or different kinds, and each is selected from the following group. Adhesiveness that is an adhesive polymer or is a mixture of one or more adhesive polymers (Mx) selected from adhesive polymers (M1) and adhesive polymers (M2) and non-adhesive polymers "Basic structure of the invention" and "improved structure 1 of the invention" prepared from a polymer
~ Coextruded laminated film described in "Improved constitution 4 of the invention": (2) at least one selected from olefin copolymer elastomers modified with unsaturated fatty acid anhydride; (3) with unsaturated fatty acid anhydride Modified ethylene-vinyl acetate copolymer; (4) Copolymer of 1-olefin and unsaturated aliphatic carboxylic acid; (5) From two or more groups of the above groups (1) to (4) A mixture of two or more polymers each selected from one or more.

[Improved Structure 6 of the Invention] When the adhesive polymer (M1) and the adhesive polymer (M2) are the same or different kinds of adhesive polymers, the adhesive polymer is modified. As the one or more selected from the modified olefin polymer resin and the olefin polymer wax modified with unsaturated fatty acid anhydride, the unsaturated fatty acid anhydride is maleic anhydride. A blended resin, an ethylene-based polymer wax, a propylene polymer wax, or a mixture of two or more selected from them, or an adhesive polymer which is an olefin copolymer elastomer modified with an unsaturated fatty acid anhydride. Ethylene-propylene copolymer elastomer, ethylene-1-butene copolymer elastomer and propylene-1-butene whose saturated fatty acid anhydride is maleic anhydride Or an ethylene-vinyl acetate copolymer in which the adhesive polymer is modified with an unsaturated fatty acid anhydride, and the unsaturated fatty acid anhydride is maleic anhydride. Ethylene is selected as the 1-olefin when the adhesive polymer is a copolymer of 1-olefin and an unsaturated aliphatic carboxylic acid and the unsaturated aliphatic carboxylic acid (meta ) A coextruded laminated film as described in "basic constitution of invention" and "improved constitution 1 of invention" to "improved constitution 5 of invention", in which acrylic acid is a copolymer selected.

[Improved Structure 7 of the Invention] Layer (A) // adhesive polymer made of polyamide resin (N1) in a layer arrangement viewed from the outside
(M1) layer (B) // polyamide resin (N2) layer (C) // adhesive polymer (M2) layer (D) // sealant polymer (S) layer (E )
The coextrusion laminated film described in "Basic configuration of the invention" and "Improved configuration 1 of the invention" to "Improved configuration 6 of the invention" in which a pinhole having a laminated structure consisting of is difficult to form.

<Preferred embodiment of the invention> The laminated film of the present invention is a layer (A) made of a polyamide resin (N1) in a layer arrangement viewed from the outside // a layer (B) made of an adhesive polymer (M1) // Polyamide resin (N
2) A layered structure having at least a layer (C) // a layer (D) made of an adhesive polymer (M2). The characteristic is that pinholes are less likely to occur even after repeated twisting of about 1000 times as a convenient means for realizing rigor that far exceeds various types of deformation expected in normal use.

A more preferred layer arrangement of the laminated film of the present invention is a layer structure in which a layer (E) made of a sealant polymer (S) is added to the inside of the above laminated film (on the basis of a tubular film), that is,
Layer made of polyamide resin (N1) in the layer arrangement viewed from the outside
(A) // layer of adhesive polymer (M1) (B) // polyamide resin (N2)
Layer (C) // adhesive polymer (M2) layer (D) // sealant polymer (S) layer (E), which is characterized by many repeated twists. Is a coextrusion laminated film that is less likely to cause pinholes.

<< Materials Constituting Laminated Body >> Each layer constituting the laminated film of the present invention has two or more layers formed of different materials. Among them, the layer (A) and the layer (C) made of polyamide resin (N) are, in principle, expressed by mutually different polyamide resins (N1) and polyamide resins (N2). ing. Polyamide resin (N
When 1) and the polyamide resin (N2) are different from each other, a unique and preferable property can be realized in each combination, but the case where they are the same kind is of course included in the embodiments of the present invention. Similarly, the layers (B) and (D) made of the adhesive resin (M) are expressed as belonging to different foreign compound groups from each other. The adhesive resin (M1) and the adhesive resin (M2) are usually the same kind or homologous compound in many cases because of the ease of actual availability.

<< Polyamide Resin (N) >> The polyamide resin (N) constituting the laminated film of the present invention can be roughly classified into a homopolymerized polyamide resin, a copolymerized polyamide resin and a cocondensate of both resins. Preferred examples of each are as listed below: (1) Homopolymerized polyamide resin: 6-polyamide, 7-polyamide, 11-polyamide and 12-polyamide. The polyamide resin is also called “nylon”; (2) Copolymerized polyamide resin: 6,6-polyamide, 6,7-polyamide, 6,10-polyamide, 6,12-polyamide and metaxylylenediamine- Adipic acid co-condensation polymer; (3) Co-condensation product of 6-polyamide and 6,6-polyamide (6 / 66-
Polyamide resin) and a cocondensation product of 6-polyamide and 12-polyamide (6 / 12-polyamide resin).

Of the above polyamide resins (N), homopolymerized polyamide resins are generally easy to use. The reason is that it is economically available as compared with the copolyamide resin and economically available as compared with the copolyamide resin. Among them, the preferred homopolymerized polyamide resin is
It is 6-polyamide (6-nylon).

On the other hand, the copolyamide resin is often used for the first time in applications where it is difficult to deal with the homopolyamide resin. The reason for this is that it is more expensive than the homopolymerized polyamide resin. The advantage of the copolyamide resin is that it is soft and that it is possible to select one having a combination of various properties.

<< Adhesive Polymer (M) >> The adhesive polymer (M) that constitutes the laminated film of the present invention can be roughly classified into the following: (1) Modified with unsaturated fatty acid anhydride One or more selected from olefin polymer wax modified with olefin polymer resin and unsaturated fatty acid anhydride; (2) One or more selected from olefin copolymer elastomer modified with unsaturated fatty acid anhydride (3) An ethylene-vinyl acetate copolymer modified with an unsaturated fatty acid anhydride. (4) Copolymer of 1-olefin and unsaturated aliphatic carboxylic acid (unsaturated fatty acid); (5) At least one member selected from two or more groups of the above groups (1) to (4) 2 Mixture of at least one adhesive polymer; (6) A mixture of at least one adhesive polymer selected from the above groups (1) to (5) and a non-adhesive polymer.

The above-mentioned adhesive polymer (M) can be explained in more detail as follows: ◆ The adhesive polymer (M) is unsaturated as a polyolefin resin modified with unsaturated fatty acid anhydride. Ethylene polymer resin whose fatty acid anhydride is maleic anhydride, propylene polymer resin, ethylene polymer wax and propylene polymer wax (including atactic polypropylene), and a mixture of two or more selected from them. Preferably, it is a maleic anhydride modified product of a linear low density polyethylene resin, or the unsaturated fatty acid anhydride is an olefin copolymer elastomer in which the adhesive polymer (M) is modified with an unsaturated fatty acid anhydride. Maleic anhydride ethylene-propylene copolymer elastomer, ethylene-1-butene copolymer elastomer and propylene-1-butene It is a maleic anhydride modified product of one or more elastomers selected from polymer elastomers, preferably ethylene-propylene copolymer elastomer, or the adhesive polymer (M) is modified with unsaturated fatty acid anhydride. As an ethylene-vinyl acetate copolymer,
Ethylene whose unsaturated fatty acid anhydride is maleic anhydride
Is it a modified product of vinyl acetate copolymer? ◆ Adhesive polymer
(M) is an ethylene- (meth) acrylic acid copolymer as a copolymer of 1-olefin and an unsaturated aliphatic carboxylic acid.

<< Sealant Polymer (S) >> The sealant polymer (S) that constitutes the laminated film of the present invention is a polymer that is rich in fusion bonding (melt adhesion). In other words, it is in the temperature range above the softening point. It is a polymer that easily sticks to. This polymer also includes a so-called elastomer or a soft polymer such as ethylene-vinyl acetate copolymer (EVA).

An important property that the sealant polymer (S) should have is that it exhibits a moderate viscosity (generally, a high viscosity) in addition to melting (melting) at a relatively low temperature. The significance thereof is that the sealant polymer (S) can be retained between the adhered portions in a required thickness when the fusion-bonded portions are pressure-bonded to each other at the time of melting to form a strong fusion-bonded layer at the time of solidification.

However, if the sealant polymer (S) has too low a viscosity during melting, the sealant polymer (S) flows away by itself in the process from softening to melting, or the sealant polymer (S ) Is extruded, which makes it difficult to form a fusion layer having a required thickness. As a result, the desired strength cannot be achieved when the sealant polymer (S) is solidified.

<< Layer Thickness of Each Layer of Laminated Body >> The respective layers constituting the laminated film of the present invention may have mutually different layer thicknesses. Although the change also affects molding conditions, etc., the outermost layer made of polyamide resin (N1)
Different layer thicknesses can be intentionally adopted in applications where a particularly large difference is required between the roles expected of (A) and the layer (C) made of the polyamide resin (N2) located in the inner layer.

The layer thickness of the layer (A) made of the polyamide resin (N1) constituting the coextrusion laminated film is usually 5 to 60 μm, preferably 10 to 40 μm, and the layer (B) made of the adhesive polymer (M1) is The layer thickness is usually 3 to 100 μm, preferably 5 to 40 μm, and the layer thickness of the polyamide resin (N 2) layer (C) is usually 5 to 60 μm 10
The layer thickness of the layer (D) made of 40 μm and the adhesive polymer (M2) is usually 2
A setting of 0 to 150 μm, preferably 30 to 100 μm is sufficient for most applications. In addition, sealant polymer
When (S) is used, the layer thickness of the layer (F) is usually 20.
.About.150 .mu.m, preferably 30 to 100 .mu.m.

Layer thickness of layer (A) made of polyamide resin (N1) and layer made of polyamide resin (N2) constituting the coextrusion laminated film
The sum of the layer thickness of (C) and the total layer thickness of the laminated film (80 μm)
On the other hand, it is important to set 15 to 60%, preferably 25 to 60% in order to further suppress the occurrence of pinholes.

<< Manufacturing Method of Laminated Body >> There are various methods for manufacturing a laminated body, but the coextrusion laminating method is the most prominent method for manufacturing the laminated film of the present invention, and other methods. Is unrivaled. This coextrusion laminating method is a method in which each polymer layer is fusion-laminated in an extrusion die at a stage when they are in a molten state. In order to produce the laminated film of the present invention with high productivity, it is preferable to perform inflation molding in a laminated state from a multiple annular die.

According to the coextrusion laminating method, the layers can be fused at the time when they are close to the state of being discharged from the extruder, and thus the interlayer adhesive force of the obtained laminate can be approximated to the upper limit. In addition to that, it is effective in that the time during which the high temperature polymer is exposed to air (oxygen) can be kept short.

That is, it is possible to limit undesired changes such as discoloration due to the deterioration of the polymer to such an extent that it does not pose a practical problem. This effect can meet the demand for minimizing the adverse effect of the temperature normally used for extrusion lamination exceeding 200 ° C.

[0034]

EXAMPLES The present invention will be specifically described below based on examples. However, the present invention is not of course limited to this. In addition, as a means for measuring the number of pinholes generated in Examples and Comparative Examples, a measuring machine called "Gelbo Flex Tester" was used. The "Gerbo flex test" using this measuring device is a measuring method performed by the following procedure: << humidity control of measuring piece >> 23 ° C. of original film; 65% RH
Exposed to the atmosphere for 88 h. After completion of this exposure, a measuring piece 305 mm (12 in.) X 203 mm (8 i
n.) is created in the machine direction (vertical direction) and in the direction perpendicular to it (horizontal direction), two sheets each. As a control measurement piece, two films are cut out from the original film before the exposure process by operating in the same manner as described above in the longitudinal direction and the lateral direction.

Both short sides of the exposed and unexposed measurement pieces are bound with a binding margin of 12.7 mm (0.5i).
n.) Width heat-sealed into a tubular [diameter 82.6 mm (3.2
5 in.) × length 203 mm (8 in.)].

<< Flexing operation >> The above-mentioned measuring piece is mounted on the circular head of the section "Gelbo Flex Tester" which is a pinhole generation tester, and one end of the measuring piece is fixed to the head by a clamp. Fix the edge to the device body side. At room temperature, twist the head against the main body of the device at a test speed of 40 cycles / min to the device side while twisting 440 °.
mm (3.5 in.) close and then 63. from the device without twisting.
Separate to 5 mm (2.5 in.). This treatment is applied 1000 times.

<< Measurement of the Number of Pinholes Generated >> The number of pinholes generated in the above-mentioned measurement strip film is electrostatically measured using a horoscope. That is, when a low voltage is applied to a brush-shaped contact measuring tool made by planting a copper wire and the end of the wire is brought into contact with the measuring piece, a buzzer sounds as a result of energization at a place where a pinhole exists.

[0038]

Example 1 In a layer arrangement viewed from the outside, a layer (A) made of a polyamide resin (N1) // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N2) ( C) // Layer made of adhesive polymer (M2) (D)
A laminated film consisting of multiple circular dies and a die temperature of 25
Coextrusion inflation molding was performed at 0 ° C. and a swelling ratio (blow-up ratio) of 0.6 to obtain a laminated tubular film having 4 layers of 2 types, a total layer thickness of 80 μm and a folding width of 200 mm.

The layer thickness ratio of each layer constituting the obtained laminated film is as follows: layer (A) 15 / layer (B) 10 / layer (C) 10 / layer (D) 65
(Total = 100). As can be seen, the sum of the layer thickness of the polyamide resin (N1) layer (A) and the polyamide resin (N2) layer (C) was 25% of the total layer thickness.

In the above laminated film, the polyamide resins (N1) and (N2) forming the layers (A) and (C) are 6-
Using nylon [trade name: 1021FS (manufactured by Toray)], a linear shape modified by grafting maleic anhydride as adhesive resins (M1) and (M2) forming layers (B) and (D) Low-density polyethylene [trade name: Adomer NF300 (manufactured by Mitsui Petrochemical Co., Ltd.)] was used. The number of pinholes generated in this laminated film was measured as described above. The results are shown in Table 1 together with other characteristics.

[0041]

Example 2 In a layer arrangement viewed from the outside, a layer (A) made of a polyamide resin (N1) // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N2) ( C) // Layer made of adhesive polymer (M2) (D)
// Co-extrusion inflation molding of a laminated film composed of a layer (E) made of a sealant polymer (S) from a multiple annular die at a die temperature of 250 ° C. and an expansion ratio (blow-up ratio) of 0.6. A laminated tubular film having a total layer thickness of 70 μm and a folding width of 200 mm was obtained.

The layer thickness ratio of each layer constituting the obtained laminated film is as follows: layer (A) 15 / layer (B) 10 / layer (C) 10 / layer (D) 5 /
It was layer (E) 60 (total = 100). As can be seen from this, the sum of the layer thickness of the layer (A) and the layer thickness of the layer (C) was 25% of the total layer thickness of the laminated film. This sum was the same as the value in Example 1.

In this laminated film, as the polyamide resins (N1) and (N2) forming the layer (A) and the layer (C), 6-
Polyamide resin [Product name: 1021FS (Toray)]
The same polypropylene crystalline resin as the adhesive polymers (M1) and (M2) forming the layers (B) and (D) [trade name: Polytack E
100 (manufactured by Idemitsu Kabushiki Kaisha)], and a polypropylene crystalline resin [trade name: FM201B (manufactured by Chisso)] was used as the sealant polymer (S) forming the layer (E).

The number of pinholes generated in the obtained coextruded laminated film was measured. The results are shown in Table 1 together with other characteristics.
Shown in

[0045]

Example 3 In a layer arrangement viewed from the outside, a layer (A) made of a polyamide resin (N1) // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N2) ( C) // Layer made of adhesive polymer (M2) (D)
// Co-extrusion inflation molding of a laminated film composed of a layer (E) made of a sealant polymer (S) from a multiple annular die at a die temperature of 250 ° C. and an expansion ratio (blow-up ratio) of 0.6. A laminated tubular film having a total layer thickness of 70 μm and a folding width of 200 mm was obtained.

The layer thickness ratio of each layer constituting the obtained laminated film is as follows: layer (A) 15 / layer (B) 10 / layer (C) 10 / layer (D) 5 /
It was layer (E) 60 (total = 100). As can be seen, the sum of the layer thickness of the polyamide resin (N1) layer (A) and the polyamide resin (N2) layer (C) is 2 with respect to the overall layer thickness.
5%. This sum was the same as the value in Example 1.

In this laminated film, the polyamide resin (N1) forming the layer (A) is a homopolymer resin 6-
Polyamide resin [Product name: 1021FS (Toray)] and layer (C)
Is a co-condensation resin as a polyamide resin (N2) that forms
6 / 66-Adhesive polymer forming layer (B) and layer (D) using polyamide resin [trade name: 5023FD-1 (manufactured by Ube Industries)]
An ethylene polymer resin [trade name: Atomer NF300 (manufactured by Mitsui Petrochemicals)] is used as (M1) and (M2), and an ethylene polymer [trade name: as a sealant resin (S) forming a layer (E). G5518
(Manufactured by Nippon Unicar Co., Ltd.)] was used. The number of pinholes generated in the obtained laminated film was measured as described above. The results are shown in Table 1 together with other characteristics.

[0048]

[Comparative Example 1] A layer (A) made of a polyamide resin (N1) in a layer arrangement viewed from the outside // A layer (B) made of an adhesive polymer (M1) // A layer made of a sealant resin (S) (E 3) a laminated film composed of
From a double layer annular die at a die temperature of 250 ° C. and an expansion ratio (blow-up ratio) of 0.6 by coextrusion inflation molding method, 3 layers of 3 types, a total layer thickness of 80 μm and a folding width of 20.
A 0 mm laminated tubular film was obtained. The layer thickness ratio of each layer is
(A) 25 / layer (B) 10 / layer (E) 65 (total = 100).

In this laminated film, as the polyamide resin (N1) forming the layer (A) and the adhesive polymer (M1) forming the layer (B), the same ones as in Example 1 were used. As the sealant resin (S) forming (E), the same one as in Example 2 was used. The number of pinholes generated in the obtained laminated film was measured as described above. The results are shown in Table 1 together with other properties.

[0050]

Comparative Example 2 As another laminated film, an adhesive polymer (M
1) layer (B) // polyamide resin (N2) layer (C) // sealant polymer (S) layer (E) And expansion ratio (blow-up ratio) of 0.6 by coextrusion inflation molding
A laminated tubular film having three layers of seeds, a total layer thickness of 70 μm and a folding width of 200 mm was obtained. The layer thickness ratio of each layer is 25 layers / layer (B)
(C) 15 / layer (E) 60 (total = 100).

In this laminated film, the same polyamide resin (N1) forming the layer (C), the adhesive polymer (M1) forming the layer (B) and the layer (D) as in Example 1 was used. As the sealant resin (S) forming the layer (E), the same one as in Example 2 (PP type) was used. The number of pinholes generated in the obtained laminated film was measured. The results are shown in Table 1 together with other properties.

[0052]

[Comparative Example 3] Further, a layer (A) made of a polyamide resin (N1) // a layer (B) made of a polyamide resin (N2) // a layer made of an adhesive polymer (M1)
Laminated film composed of layer (S) made of (C) // olefin resin (P1) is subjected to coextrusion inflation molding from a multiple annular die at a die temperature of 250 ° C. and a swelling ratio (blow-up ratio) of 0.6. 4 layers, total layer thickness 70μm and folding width 20
A 0 mm laminated tubular film was obtained. The layer thickness ratio of each layer is as follows: layer (A) 15 / layer (B) 10 / layer (C) 15 / layer (E) 60 (total =
100).

In the above laminated film, the polyamide resin (N1) forming the layer (A), the polyamide resin (N2) forming the layer (B), and the adhesive resin forming the layer (C) and the layer (E) (M1)
The same as in Example 3 was used as (S) and (S). The number of pinholes generated in the obtained laminated film was measured. The results are shown in Table 1 together with other properties.

[0054]

[Comparative Example 4] In a layer arrangement viewed from the outside, a layer (F) made of polyethylene (P1) // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N1) (C ) // Layer (D) made of adhesive polymer (M1) //
Layer (E) made of ethylene resin (S) as a sealant polymer
A laminated film consisting of multiple circular dies and a die temperature of 25
Coextrusion inflation molding was performed at 0 ° C and a swelling ratio (blow-up ratio) of 0.6, and 4 layers of 5 layers and a total layer thickness of 70μ
A laminated tubular film having m and a folding width of 200 mm was obtained.

The layer thickness ratio of each layer constituting the obtained laminated film is as follows: layer (F) 15 / layer (B) 5 / layer (C) 25 / layer (D) 5 / layer
(E) It was 60 (total = 100). As can be seen, the layer thickness of the polyamide resin (N1) layer (A) was 25% of the total layer thickness. This value was the same as that in Example 1.

In this laminated film, 6-polyamide resin [trade name: 1021FS (manufactured by Toray)] is used as the polyamide resin (N1) forming the layer (C), and the adhesive polymer forming the layer (B) is used. (Trade name: Atomer NF300 (manufactured by Mitsui Petrochemical Co., Ltd.)) is used as both (M1) and the adhesive polymer (M2) forming the layer (D),
As the sealant resin (S) forming the layer (E), an ethylene polymer resin [trade name: G5518 (manufactured by Nippon Unicar Co., Ltd.)] was used. The number of pinholes generated in the obtained laminated film was measured as described above. The results are shown in Table 1 together with other characteristics.
Shown in

[0057]

EFFECT OF THE INVENTION The coextruded laminated film of the present invention can exhibit the following various effects: (1) It exhibits sufficient reliability even in applications where gas permeation, especially oxygen, is disliked. ) Mechanical properties sufficient for practical use In particular, in addition to tensile strength, tensile elongation and Young's modulus, it is possible to realize particularly low haze (haze value) in appearance (3) While keeping the layer thickness of the polyamide resin layer as it is The number of pinholes generated can be significantly reduced. (4) Coextrusion laminating can provide a laminated film that is considerably soft as a whole. However, it is inevitable that a laminated film formed by another lamination method such as dry lamination becomes hard.

[0058]

[Table 1]

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Claims (8)

[Claims] 1. A layer (A) made of a polyamide resin (N1) in a layer arrangement seen from the outside // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N2) (C ) // Layer (D) made of adhesive polymer (M2)
A coextrusion laminated film that is less likely to generate pinholes and is formed of four or more layers having at least a laminated structure of 2. The layer thickness of the layer (A) made of polyamide resin (N1) constituting the coextruded laminated film is 5 to 60 μm, and the layer thickness of the layer (B) made of the adhesive polymer (M1) is 3 to. 100 μm, the layer thickness of the polyamide resin (N2) layer (C) is 5 to 60 μm, and the adhesive polymer
The layer thickness of the layer (D) made of (M2) is 20 to 150 μm.
The coextruded laminated film according to. 3. The overall layer of the laminated film, wherein the sum of the layer thickness of the polyamide resin (N1) layer (A) and the layer thickness of the polyamide resin (N2) layer (C) constituting the coextruded laminated film is The coextrusion laminated film according to claim 1 or 2, which has a thickness of 10 to 60%. 4. The polyamide resin layer is a polyamide resin (N1) and a polyamide resin (N2) which are the same or different from each other and each of which is one or more selected from homopolymerized polyamide resin and copolymerized polyamide resin. The coextrusion laminated film according to claim 1, which is a layer formed of a polyamide resin. 5. A polyamide resin (N1) and a polyamide resin
(N2) is selected from the following homopolymerized polyamide resin group 1
One or more or a combination of two or more homopolymerized polyamide resins thereof, or one or more selected from the following copolymerized polyamide resin group or a combination of two or more thereof copolymerized polyamide resins, or The coextruded laminated film according to any one of claims 1 to 4, which is selected from cocondensates: (1) homopolymerized polyamide resin: 6-polyamide, 7-polyamide, 11-polyamide and 12-polyamide; Polymerized polyamide resin: 6,6-polyamide, 6,7-polyamide, 6,10-polyamide, 6,12-polyamide and metaxylylenediamine-adipic acid co-condensation polymer; (3) 6-polyamide and 6,6 -Cocondensation with polyamide and 6-
Co-condensate of polyamide and 12-polyamide. 6. Adhesive polymer (M1) and adhesive polymer (M2)
Are mutually the same kind or different kinds of adhesive polymers, each is an adhesive polymer selected from the following group, or selected from the adhesive polymer (M1) and the adhesive polymer (M2) Claims 1 to 3 prepared from an adhesive polymer which is a mixture of one or more adhesive polymers (Mx) and a non-adhesive polymer
The coextrusion laminated film according to any one of 5: (1) One or more selected from an olefin polymer resin modified with an unsaturated fatty acid anhydride and an olefin polymer wax modified with an unsaturated fatty acid anhydride (2) one or more selected from olefin copolymer elastomers modified with unsaturated fatty acid anhydride; (3) ethylene-vinyl acetate copolymer modified with unsaturated fatty acid anhydride; (4) Copolymer of 1-olefin and unsaturated aliphatic carboxylic acid; (5) A mixture of two or more polymers each selected from one or more groups selected from the two or more groups of the above groups (1) to (4). 7. Adhesive polymer (M1) and adhesive polymer (M2)
When the adhesive polymers are the same or different from each other, the adhesive polymer is selected from an olefin polymer resin modified and an olefin polymer wax modified with an unsaturated fatty acid anhydride. As the one or more kinds, it is an ethylene-based polymer resin whose unsaturated fatty acid anhydride is maleic anhydride, a propylene-based polymer resin, an ethylene-based polymer wax and a propylene polymer wax, and a mixture of two or more kinds selected from them. As an olefin copolymer elastomer whose adhesive polymer is modified with unsaturated fatty acid anhydride, an ethylene-propylene copolymer elastomer whose unsaturated fatty acid anhydride is maleic anhydride, ethylene-1-butene copolymer Combined elastomer and propylene-1
-One or more elastomers selected from butene copolymer elastomers, or ethylene-vinyl acetate copolymers in which the adhesive polymer is modified with unsaturated fatty acid anhydride, and the unsaturated fatty acid anhydride is maleic anhydride. If the elastomer is an acid or the adhesive polymer is a copolymer of 1-olefin and an unsaturated aliphatic carboxylic acid, ethylene is selected as the 1-olefin and the unsaturated aliphatic carboxylic acid is ( The coextrusion laminated film according to any one of claims 1 to 6, wherein (meth) acrylic acid is a selected copolymer. 8. A layer (A) made of a polyamide resin (N1) // a layer (B) made of an adhesive polymer (M1) // a layer made of a polyamide resin (N2) (C ) // Layer (D) made of adhesive polymer (M2)
// The coextrusion laminated film according to any one of claims 1 to 6, which is less likely to form a pinhole having a laminated structure composed of the layer (E) made of the sealant polymer (S).