JPH0577371A - Laminated film - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a polypropylene film having a good balance of flexibility and mechanical strength. [Structure] (A) A layer made of a resin composition containing 20 to 100% by weight of an amorphous polyolefin having a propylene component content of 50% by weight or more and 80 to 0% by weight of a crystalline polypropylene, and (B) A film in which at least three layers of crystalline polypropylene are laminated, and
A laminated film in which both outer surface layers are composed of the layer (B).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated film having at least three layers. More specifically, the present invention relates to a laminated film having flexibility, mechanical strength, and excellent transparency, haze, and gloss as a soft polypropylene film comparable to a soft vinyl chloride film or a vinylon film.

[0002]

2. Description of the Related Art In recent years, a soft vinyl chloride film containing a plasticizer has been widely used as a soft film. However, soft vinyl chloride resins have social factors such as toxicity and transfer due to bleeding out of plasticizers and monomers, and acid rain due to generation of hydrogen chloride during incineration.

On the other hand, as a soft film comparable to the above soft vinyl chloride film, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ionomer, linear low density polyethylene, extremely low density polyethylene, ethylene / propylene. Some are mainly ethylene such as copolymers. However, these soft films mainly composed of ethylene are inferior to the soft vinyl chloride film in terms of transparency, haze, gloss, etc., and flexibility and mechanical strength,
In particular, there is a drawback that the balance with impact strength is lacking.

Vinylon films, which are often used for fiber packaging, have excellent softness,
Unlike olefin-based materials, there is a problem that the cost becomes extremely high. On the other hand, in the crystalline polypropylene film, transparency and haze are maintained by using a propylene random copolymer whose melting point is lowered by randomly copolymerizing propylene and ethylene and / or α-olefin. At the same time, it is done by giving it flexibility. However, with the current technology, it is difficult to provide a crystalline polypropylene resin with flexibility comparable to that of a soft vinyl chloride film.

[0005]

In view of the above situation, the present invention provides a soft film other than the soft vinyl chloride film, particularly good transparency, haze and gloss, and flexibility and mechanical strength, particularly It is intended to provide a film having high impact resistance. In addition, the present invention has various uses from the above features, for example, packaging films such as food packaging and fiber packaging, medical applications such as infusion bag films, metal protective films, base materials for adhesive tapes, and civil engineering / building fields. The purpose of the present invention is to provide a film suitable for use as a film for building materials in The inventors of the present invention have conducted extensive studies for the above purpose, and as a result, an amorphous polyolefin having a specific composition, or a layer formed by mixing the amorphous polyolefin and crystalline polypropylene in a predetermined ratio, and crystalline polypropylene The present invention has been completed based on the finding that a film in which the crystalline polypropylene layer constitutes the outermost layer of the film, which is a laminated film composed of the following layers, meets the above-mentioned object.

[0006]

According to the present invention, (A)
A layer comprising a resin composition comprising 20 to 100% by weight of an amorphous polyolefin having a propylene component content of 50% by weight or more and 80 to 0% by weight of a crystalline polypropylene, and (B) comprising a crystalline polypropylene. There is provided a laminated film having at least three layers and having both outer surface layers composed of the layer (B).

[0007]

The laminated film of the present invention is configured as described above and is excellent in transparency, haze and gloss by coextruding an amorphous polymer containing propylene and crystalline polypropylene to form a laminated composite, and The film has high flexibility while maintaining the original mechanical strength of polypropylene.

The present invention will be described in detail below. The amorphous polyolefin (hereinafter referred to as amorphous polyolefin) used in the layer (A) of the present invention may be an amorphous olefin polymer having a propylene component content of 50% by weight or more. For example, amorphous polypropylene or a copolymer of propylene and another α-olefin can be used. When the propylene component content of the amorphous polyolefin is less than 50% by weight, the compatibility with the crystalline polypropylene of the layer (B) is lowered, which is not preferable.

The above-mentioned amorphous polyolefin means boiling n-
The heptane-insoluble matter, that is, the Soxhlet-extractable insoluble matter by boiling n-heptane is 70% by weight or less, preferably 60% by weight or less. Boiling n-heptane insoluble matter 70
If it is more than 10% by weight, the ratio of the amorphous portion is small, and it is not possible to impart the desired sufficient flexibility to the obtained film. The above-mentioned amorphous polyolefin of the layer (A) preferably has a number average molecular weight of 1,000 to 2
0,000, preferably 1,500 to 100,000
Is. When the number average molecular weight exceeds 200,000, it is difficult to form a film, and when the number average molecular weight is less than 1,000, the mechanical strength decreases. In the present invention, the amorphous polyolefin may be used alone or in combination of two or more.

As the amorphous polypropylene, atactic polypropylene produced as a by-product during the production of crystalline polypropylene may be used, or it may be produced from raw materials and used. Further, the copolymer of propylene and other α-olefin can be used by purposely producing it from a raw material so as to contain a predetermined propylene component. In the case of intended production, it can be obtained, for example, by polymerizing a raw material monomer in the presence / absence of hydrogen using a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. From the viewpoint of the stability of the raw material supply and the stability of the quality, it is preferable to use a predetermined amorphous polyolefin produced for the purpose. In addition, if there is a suitable commercial product, a commercial product can be appropriately selected and used.

As the amorphous polyolefin of the layer (A) of the present invention, specifically, polypropylene, propylene / ethylene copolymer, propylene / butene-1 copolymer having predetermined characteristics such as the above-mentioned propylene component content. , Propylene / butene-1 / ethylene-3 terpolymer, propylene / hexene-1 / octene-1 / 3 terpolymer, propylene / hexene-1 / 4-methylpentene-1 / 3 terpolymer, etc. An amorphous polyolefin whose main component is the propylene component of When the amorphous polyolefin is a propylene / ethylene copolymer, it is desirable that the ethylene component content is 0 to 30% by weight, preferably 1 to 20% by weight. When the ethylene component content is more than 30% by weight, the obtained film becomes too soft.

When the amorphous polyolefin of the layer (A) of the present invention is a propylene / butene-1 copolymer, the butene-1 component content is 50% by weight or less, preferably 1 to 45.
%, More preferably 5 to 44% by weight is desirable. Since the propylene / butene-1 copolymer has a large tensile elongation, impact resilience and cohesive force, it is suitably used as the amorphous polyolefin of the layer (A). Specifically, for example, a commercially available product such as REXTAC made by Rexene Co. of America can be used.

The crystalline polypropylene used in the layer (A) of the present invention includes polypropylene which is usually commercially available for extrusion molding, injection molding, blow molding, etc., and is a boiling n-heptane insoluble isotactic polypropylene. Say. In this case, it may be a propylene homopolymer or a copolymer of isotactic polypropylene having stereoregularity and another α-olefin.
The crystalline polypropylene may be a commercially available product or may be manufactured and used. The production of crystalline polypropylene is not particularly limited, and can be appropriately selected and applied from the conventional methods for producing crystalline polypropylene.

As the α-olefin used for copolymerization with crystalline polypropylene, α-olefin having 2 to 8 carbon atoms is used.
-Olefins such as ethylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1 and the like are preferred. Among these, ethylene or butene-1 is particularly preferable.

In the present invention, the crystalline polypropylene is preferably a propylene homopolymer, a propylene / ethylene random copolymer or a block copolymer containing an ethylene component in an amount of 30% by weight or less, preferably 1 to 25% by weight. Examples thereof include a random copolymer or a block copolymer of propylene / butene-1 containing 20% by weight or less of butene-1. Among these, a copolymer of ethylene or butene-1 and propylene is particularly preferable in terms of applications such as a film or sheet of the resin composition of the present invention. The crystalline polypropylene of the layer (A) can be used alone or in combination of two or more.

Furthermore, the amorphous polyolefin and / or crystalline polypropylene of the layer (A) in the present invention may be modified. The amorphous polyolefin or crystalline polypropylene, for example, unsaturated carboxylic acid such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters, acid anhydrides, metals It can be used after being modified with a derivative such as a salt. Among these modified products, those modified with maleic anhydride or itaconic anhydride are preferably used, and those modified with maleic anhydride are more preferably used.

In the present invention, the method for preparing the resin composition in which the amorphous polyolefin (A) and the crystalline polypropylene are blended is not particularly limited, and is conventionally used in the conventional method for producing polypropylene compositions. It can be carried out by heat melting and kneading using a known method, for example, a kneader, a Banbury mixer, a kneader such as a roll, a single-screw or twin-screw extruder, and the like. Further, in the present invention, various additives and fillers, such as a heat resistance stabilizer, an antioxidant, a light stabilizer, an antistatic agent, a lubricant, etc., may be added to the resin composition constituting the layer (A) as desired. Nucleating agents, flame retardants, pigments or dyes, calcium carbonate, calcium sulfate, barium sulfate,
Magnesium hydroxide, mica, talc, clay and the like can be added. Furthermore, other thermoplastic resins,
Thermoplastic elastomers, rubbers and the like can be blended as necessary, and these can be crosslinked.

The resin composition of the layer (A) of the present invention comprises the above-mentioned amorphous polyolefin alone or the above-mentioned amorphous polyolefin and crystalline polypropylene, and the amorphous polyolefin is 20 to 100% by weight, preferably 25-10
It can be obtained by blending so as to be 0% by weight. If the amorphous polyolefin is less than 20% by weight, sufficient flexibility cannot be obtained.

The crystalline polypropylene used in the layer (B) of the present invention may be the same as the crystalline polypropylene used in the layer (A), and in particular, in order to bring out the characteristics of the soft film. It is preferable to use a propylene-based random copolymer having a melting point of 150 ° C. or lower.

The laminated film of the present invention has the above-mentioned (A).
Usually, the layers and the layer (B) are alternately laminated, and the number of layers of the layers (A) and (B) to be laminated is not particularly limited, but the layer is composed of at least three layers, that is, the outermost layer, that is, The layers forming both outer surfaces are composed of the layer (B). For example, (B) / (A) / (B) or (B) /
The laminated film can be formed by a laminated combination such as (A) / (B) / (A) / (B). In the present invention, the layer (A) contributes to impart flexibility to the entire film, but the amorphous polyolefin used has strong surface tackiness, and particularly when it has a low molecular weight, the surface tackiness is remarkable.
On the other hand, the layer (B) has little contribution to the flexibility of the film, but has almost no surface tackiness. Therefore, as described above, the layer (B) constitutes the outermost layers on both sides of the laminated film of the present invention, and the layer (A) constitutes the inner layer, thereby forming a flexible film having no surface tackiness. be able to.
In the laminated film of the present invention, another thermoplastic resin layer, for example, nylon, EVAL, or the like may be laminated and inserted between the layers (A) and (B) to provide a gas barrier.

In the present invention, the thickness of each layer constituting the laminated film is not particularly limited and can be arbitrarily selected. Usually, each layer is about 2-1000 μm
Is formed in the range of. Further, the thickness ratio of the (A) layer and the (B) layer is not particularly limited. Preferably, as described above, the (A) layer contributes to the flexibility of the film,
Since the (B) layer has a surface tackiness preventing function, the total thickness of the (A) layers, which is the total thickness of the (A) layers constituting the film, is about 20 to 99% of the laminated film thickness, More preferably, it is configured to be 30 to 95%.

The method for producing the laminated film of the present invention is not particularly limited. For example, a coextrusion laminating method, a lamination method, a dry lamination method or the like can be used. Of these, the coextrusion laminating method of melt bonding is preferable. Specifically, for example, a method of melt-extruding using an extruder suitable for the number of laminated layers, laminating in a molten state by a known method such as a T-die method or an inflation method, and then cooling with a cooling roll, water cooling or air cooling is used. It can be made into a laminated film. When a cooling roll is used, it is preferable to use an air knife or an air chamber together for rapid cooling. Moreover, in the inflation method, it is preferable to perform rapid cooling by water cooling.

The laminated film of the present invention can be surface-treated in order to improve printability, laminating and pressure-sensitive adhesive coating properties. Examples of the surface treatment method include corona discharge treatment, plasma treatment, flame treatment, acid treatment and the like, and any method can be used in the present invention.
Since continuous processing is possible and can be easily performed before the winding step in the film manufacturing process, plasma processing,
Flame treatment and corona discharge treatment are preferable, and among these, corona discharge treatment is most preferable from the viewpoint of simplicity.

The laminated film of the present invention is laminated, cooled and solidified as described above, optionally treated as described above, and then wound up to the next step, for example, printing, laminating, adhesive. It can be used for the intended purpose through secondary processing steps such as coating and heat sealing. The laminated film of the present invention is applicable to various uses by itself and is useful, and further laminated with polyester, nylon, stretched polypropylene film or the like to obtain its mechanical strength,
It is also possible to improve functions such as gas barrier properties and printing performance.

[0025]

EXAMPLES The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples. In addition, in the following Examples of the present invention, the measurement of each inspection item was performed by the following methods.

[Tensile Properties] Tensile test was conducted according to JIS-Z17.
02, (1) Tensile yield strength (kg / cm
⁴ ) of ² ), (2) tensile breaking strength (kg / cm ² ), (3) tensile elongation (%), (4) tensile modulus (kg / cm ² ).
The items were evaluated. [Haze: Haze (%)] The haze was measured according to ASTM D1003. [Gloss (%)] It was performed according to ASTM D2457. [Elmendorf tear strength (kg / cm)] JIS-P
It carried out according to 8116. [Dirt Impact (g / 26in)] ASTM D1
709.

Examples 1 to 4 [Preparation of resin composition for layer (A)] As the resin composition constituting the layer (A), the density was 0.86 g / cm ³ , the propylene content was 65% by weight, and butene-1 was contained. Amorphous polyolefin with an amount of 35% by weight and a melt viscosity of 10,000 cps (190 ° C.) (manufactured by Lexen, trade name APAO RT2780)
And a density of 0.90 g / cm ³ and a melt flow rate (M
FR) (230 ° C.) = 1.0 g / 10 minutes of crystalline polypropylene (manufactured by Ube Industries, Ltd., trade name B301H) at a weight ratio of 50/50 and mixed at a temperature of 200 ° C. for 30 minutes.
A resin composition prepared by melt-kneading for 1 minute was used.

[Molding of Laminated Film] The resin composition prepared above is used in the layer (A) and has a density of 0.91 g / cm 3.
³ , melt flow rate (MFR) (230 ℃) = 9g
A crystalline polypropylene (manufactured by Ube Industries, Ltd., trade name RF395) having a melting point of 138 ° C. for / 10 minutes was used for the (B) layer. Outer layer / middle layer / inner layer (B) / (A) / (B)
So as to have the thickness ratio shown in Table 1, and using three extruders each having three independent layers and a three-layer die connected thereto,
After co-extruding the melted three layers, it was rapidly cooled with an air ring and a water-cooled sizing ring, blow-up molded into a tubular film, and immediately wound up.
A layer laminated film was obtained. The characteristics of each obtained three-layer laminated film were measured. The results are shown in Table 1.

[0029]

[Table 1]

Example 5 The resin composition used for the layer (A) is shown in Table 1 in the same manner as in Example 1 except that the mixing ratio of amorphous polyolefin and crystalline polypropylene was adjusted to 70/30. A three-layer laminated film having a total thickness was obtained. The characteristics of the obtained three-layer laminated film were measured, and the results are shown in Table 1.

Example 6 The resin composition used for the layer (A) is shown in Table 1 in the same manner as in Example 1 except that the mixing ratio of amorphous polyolefin and crystalline polypropylene was adjusted to 30/70. A three-layer laminated film having a total thickness was obtained. The characteristics of the obtained three-layer laminated film were measured, and the results are shown in Table 1.

Comparative Example 1 As a film raw material, a low density polyethylene (LDPE) having a density of 0.92 g / cm ³ and a melt index (MI) (230 ° C.) = 0.9 g / 10 min (Ube Industries, Ltd.)
Manufactured by the trade name RF019), and using an inflation film molding apparatus equipped with an extruder and a ring-shaped die, the tube-shaped film is wound up to a thickness of 50 μm.
A DPE monolayer film was obtained. The characteristics of the obtained film were measured, and the results are shown in Table 1.

Comparative Examples 2 to 5 As film raw materials, the density was 0.92 g / cm, respectively.
³ , MI (230 ° C.) = 0.8 g / 10 min linear low density polyethylene (LLDPE) (trade name, FB123M, manufactured by Ube Industries, Ltd.), density 0.91 g / cm ³ , MI (2
30 ° C.) = 1.5 g / 10 minutes ultra-low density polyethylene (VLDPE) (manufactured by Ube Industries, Ltd., trade name Z517)
A), density 0.93 g / cm ³ , MI (230 ° C.) =
Ethylene / vinyl acetate copolymer (EVA) having 2.0 g / 10 minutes and a vinyl acetate content of 15% by weight (Ube Industries, Ltd.)
Made, trade name V215), density 0.96 g / cm ³ , MI
(230 ° C.) = 0.1 g / 10 min High-density polyethylene (HDPE) (manufactured by Tosoh Corporation, trade name 6000) (Comparative Example 5) was used, and the results are shown in Table 1 in the same manner as in Comparative Example 1. Thickness of LLDPE monolayer film (Comparative Example 2), VL
A DPE single layer film (Comparative Example 3), an EVA single layer film (Comparative Example 4) and an HDPE single layer film (Comparative Example 5) were obtained. The characteristics of each of the obtained films were measured, and the results are shown in Table 1.

Comparative Example 6 Using the three-layer laminated film molding apparatus used in Example 1, the same raw material as the crystalline polypropylene used as the component of the resin composition for layer (B) in Example 1 was melted from each extruder. A 60 μm film was obtained in the same manner as in Example 1 except that three layers were coextruded. The characteristics of the obtained film were measured, and the results are shown in Table 1.

As is clear from the above Examples and Comparative Examples, the three-layer laminated film comprising the layers (A) and (B) of the present invention has a tensile elongation and other tensile properties as compared with the films of Comparative Examples. It can be seen that there is a good balance with, flexibility, and excellent mechanical strength. Further, it can be seen from the values of haze and gloss that the transparency, haze and gloss are also good.

[0036]

INDUSTRIAL APPLICABILITY The laminated film of the present invention is a soft film having good transparency, haze and gloss, and having a good balance of flexibility and mechanical strength such as impact resistance, and is socially friendly due to environmental pollution. It can be applied to various applications in place of the problematic soft vinyl chloride film.

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[Procedure amendment]

[Submission date] April 30, 1992

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[0029]

[Table 1]

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Examples 7 to 8 [(A) Layer Resin Composition] The resin constituting the (A) layer has a density of 0.88 g / cm ³ and a melt flow rate (M).
FR) (230 ° C.) = 8.4 g / 10 min of amorphous polypropylene (boiling n-heptane insoluble matter = 46%, number average molecular weight = 48,000) was used. [Structure of Laminated Film] Example 7: The composition (A)
Layer, density 0.90 g / cm ³ , melt flow rate (MFR) (230 ° C.) = 2.7 g / 10 min, melting point 1
Crystalline polypropylene (trade name: FL453, manufactured by Ube Industries, Ltd.) at 39 ° C. was used for the (B) layer. Outer layer / middle layer /
As the inner layer, (B) / (A) / (B) had the thickness ratio shown in Table 1. Example 8: The above composition in the (A) layer and a density of 0.91
g / cm ³ , melt flow rate (MFR) (230
C.) = 9.0 g / 10 min, melting point 138.degree. C. crystalline polypropylene (manufactured by Ube Industries, Ltd., trade name RF395) was used for the (B) layer. Outer layer / middle layer / (B) as inner layer /
The thickness ratio (A) / (B) was set to the thickness ratio shown in Table 1. [Molding of Laminated Film] Using the three extruders each having three independent layers and the three-layer die connected thereto to co-extrude the melted three layers so as to have the above-described configuration, and then air ring and water-cooled sizing ring. Then, it was rapidly cooled to a tubular film, blow-up molded, and immediately wound up to obtain a three-layer laminated film having the total thickness shown in Table 1. The characteristics of each obtained three-layer laminated film were measured. The results are shown in Table 1. As is clear from the above Examples and Comparative Examples, the three-layer laminated film comprising the (A) layer and the (B) layer of the present invention has a balance between tensile elongation and other tensile properties as compared with the films of Comparative Examples. It is found that the material has good hardness, flexibility, and excellent mechanical strength. Also, transparency from the value of haze and gloss,
It can be seen that haze and gloss are also good. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 19, 1992

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When the amorphous polyolefin of the layer (A) of the present invention is a propylene / butene-1 copolymer, a copolymer containing propylene as a main component and a copolymer containing butene-1 as a main component. , Propylene and butene-1 are the main components. It is desirable that these main components are 50% by weight or more and the remaining components are less than 50% by weight, preferably 1 to 45% by weight, more preferably 5 to 44% by weight. propylene·
All of the butene-1 copolymers have high tensile elongation, impact resilience and cohesive force, and can be optionally used as the amorphous polyolefin of the (A) layer. Specifically, for example, a commercially available product such as REXTAC made by Rexene Co. of America can be used.

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The laminated film of the present invention has the above-mentioned (A).
Usually, the layers and (B) are alternately laminated, and the number of layers (A) and (B) to be laminated is not particularly limited, but it is composed of at least three layers and is the outermost layer, that is, both. The layer forming the outer surface is composed of the layer (B). For example, (B) / (A) / (B) or (B) /
The laminated film can be formed by a laminated combination such as (A) / (B) / (A) / (B). In the present invention, the layer (A) contributes to impart flexibility to the entire film, but the amorphous polyolefin used has strong surface tackiness, and particularly when it has a low molecular weight, the surface tackiness is remarkable.
On the other hand, the layer (B) has little contribution to the flexibility of the film, but has almost no surface tackiness. Therefore, as described above, the layer (B) constitutes the outermost layers on both sides of the laminated film of the present invention, and the layer (A) constitutes the inner layer, thereby forming a flexible film having no surface tackiness. be able to.
Further, the laminated film of the present invention comprises another thermoplastic resin layer between the (A) layer and the (B) layer, for example, nylon for imparting a gas barrier, polyvinyl alcohol, a saponified ethylene / vinyl acetate copolymer. , Polyester or the like may be inserted in layers.

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[Table 1]

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Comparative Example 1 As a film raw material, a low density polyethylene (LDPE) having a density of 0.92 g / cm ³ and a melt index (MI) (190 ° C.) of 0.9 g / 10 min (Ube Industries, Ltd.)
Manufactured by trade name F019), using an extruder and an inflation film molding device equipped with a ring-shaped die,
LDPE with a film thickness of 50 μm
A monolayer film was obtained. The characteristics of the obtained film were measured, and the results are shown in Table 1.

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Comparative Examples 2 to 5 As film raw materials, the density was 0.92 g / cm, respectively.
³ , MI (190 ° C.) = 0.8 g / 10 min linear low density polyethylene (LLDPE) (trade name, FB123M, manufactured by Ube Industries, Ltd.), density 0.91 g / cm ³ , MI (1
90 ° C.) = 1.5 g / 10 min ultra-low density polyethylene (VLDPE) (manufactured by Ube Industries, Ltd., trade name Z517)
A), density 0.93 g / cm ³ , MI (190 ° C.) =
Ethylene / vinyl acetate copolymer (EVA) having 2.0 g / 10 minutes and a vinyl acetate content of 15% by weight (Ube Industries, Ltd.)
Made, trade name V215), density 0.96 g / cm ³ , MI
(190 ° C.) = 0.1 g / 10 min High Density Polyethylene (HDPE) (Tosoh Corp., trade name 6000) (Comparative Example 5) was used and shown in Table 1 in the same manner as Comparative Example 1. Thickness of LLDPE monolayer film (Comparative Example 2), VL
A DPE single layer film (Comparative Example 3), an EVA single layer film (Comparative Example 4) and an HDPE single layer film (Comparative Example 5) were obtained. The characteristics of each of the obtained films were evaluated, and the results are shown in Table 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takafumi Manabe, Takafumi Manabe 3-1 Ube Industries Co., Ltd., 3-1 Chikko Shinmachi, Sakai City, Osaka Prefecture (72) Inventor Isao Nagayasu 3-1, Tsukiko Shinmachi, Sakai City, Osaka Prefecture Ube Industries Co., Ltd. Inside the Sakai Plant (72) Inventor Mutsuo Emoto 3-1 Chikko Shinmachi, Sakai City, Osaka Prefecture Ube Industries Ltd. Inside the Sakai Plant

Claims (3)

[Claims] 1. An amorphous polyolefin having a propylene component content of (A) 50% by weight or more is 20 to 100% by weight.
And a layer made of a resin composition containing 80 to 0% by weight of crystalline polypropylene and (B) a layer made of crystalline polypropylene, which are laminated in at least three layers,
A laminated film in which both outer surface layers are composed of the layer (B). 2. The laminated film according to claim 1, wherein the amorphous polyolefin is a propylene / butene-1 copolymer. 3. The laminated film according to claim 1, wherein the crystalline polypropylene forming the layer (B) is a propylene-based random copolymer having a melting point of 150 ° C. or lower.