JP2000218745A - Polyethylene laminated film - Google Patents

Abstract

(57) [Abstract] [Problem] It is excellent in flexibility, transparency, uniformity of stretching, and
Provided is a polyolefin-based laminated film having a strong peeling strength at a lamination interface.
1 is 50% by weight or more, and 20 to 100% by weight of an amorphous polyolefin having a boiling n-heptane insoluble content of 60% by weight or less;
A polyethylene-based laminated film comprising a resin composition of 80% by weight, a layer (B) composed of polyethylene produced by a metallocene catalyst, and a layer (A) and a layer (B) laminated. (B) The polyethylene produced by the metallocene catalyst constituting the layer has a density of 0.890 to 0.935 g / c.
Those having m ³ and a molecular weight distribution of 2.2 to 5.5 are preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soft polyethylene laminated film comprising at least two layers. Specifically, the flexible polyethylene-based laminated film of the present invention is a laminated film having a layer containing amorphous polypropylene having specific properties and a layer made of polyethylene produced using a specific catalyst as constituent layers. Thus, the lamination surface has a strong interfacial peel strength, and is excellent in transparency and uniform stretchability.
This laminated film is used for a surface protective film, a dicing film, an interior film such as a table cloth, and the like.

[0002]

2. Description of the Related Art Conventionally, as a soft film, a soft polyvinyl chloride film containing a plasticizer has been often used. However, the use of a polyvinyl chloride film as a soft polyvinyl chloride film has become a social problem. For example, a harmful gas is generated at the time of incineration, and the contained plasticizer adversely affects living organisms and the environment. Therefore, as a soft film material replacing the polyvinyl chloride film, a film using a polyolefin-based material that does not generate harmful gas during incineration is being developed.
Examples of the polyolefin-based film material include polypropylene, propylene-ethylene copolymer, low-density polyethylene, high-density polyethylene, and linear low-density polyethylene.

[0003]

However, conventional polyolefin-based films are inferior in various points as compared with soft polyvinyl chloride films. For example, a film mainly composed of polypropylene has problems such as high crystallinity, flexibility, stretchability and a narrow range of forming conditions of the film, and a film mainly composed of polyethylene has transparency and mechanical strength. And heat resistance. For the purpose of improving these problems, various research and development have been promoted, and films and laminated films composed of a blend composition obtained by combining various olefin materials have been proposed. For example, Japanese Patent Application Laid-Open No.
JP 300548 discloses a film comprising a blend composition of polypropylene and a block copolymer containing a polypropylene-ethylene random copolymer as a main component. There is also a proposal of a film having flexibility by blending polypropylene with a thermoplastic elastomer such as styrene / ethylene / butylene / styrene or ethylene propylene rubber. These films have improved flexibility, but lacked sufficient transparency due to compatibility with the materials to be blended with the polypropylene, and were stretched in multiple directions compared to soft polyvinyl chloride films. In this case, uniform stretchability and moldability were insufficient.

Japanese Patent Application Laid-Open No. 6-927 discloses that a layer composed of a resin composition mainly containing an amorphous polyolefin having a propylene and / or butene-1 content of 50% by weight or more and a polyethylene composed of polyethylene. A laminated film having a layer as a constituent layer has been proposed. This laminated film has almost the same flexibility and transparency as a soft polyvinyl chloride film. However, when this laminated film is repeatedly bent or partially stretched by vacuum forming, etc.,
The layer containing the amorphous polyolefin as a main component and the polyethylene layer may be easily peeled off at the interface. In addition, uniform stretchability when stretched in multiple directions was insufficient as compared with a soft polyvinyl chloride film.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a polyolefin-based laminated film having less of the above-mentioned problems, that is, excellent in flexibility, transparency, and uniformity of stretching, and having high peel strength at the lamination interface. With the goal.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have studied the properties of films and laminated films of blend compositions using various polyolefins. As a result, a laminated film having a layer composed mainly of an amorphous polyolefin having specific characteristics and a layer made of polyethylene produced using a specific catalyst has a strong interfacial peel strength on the laminated surface, and The present inventors have found that flexibility, transparency, and uniformity of stretching are good, and have reached the present invention.

That is, according to the present invention, in the (A) layer, the content of propylene and / or butene-1 is 50% by weight or more;
A resin composition comprising 20 to 100% by weight of an amorphous polyolefin having an amount of boiling n-heptane insolubles of 60% by weight or less, and 0 to 80% by weight of crystalline polypropylene,
The layer (B) is a polyethylene-based laminated film in which the layer (A) and the layer (B) are laminated and made of polyethylene produced with a metallocene catalyst.

It is generally known that a laminated film having a polyethylene layer as a constituent layer has a problem that the peel strength at the lamination interface is low. A feature of the present invention is that it has been found that the lamination interface of a film obtained by laminating a layer containing a specific amorphous polyolefin as a main component of the present invention and a layer made of polyethylene produced by a metallocene catalyst has a strong laminate strength. is there. Although the reason why the peel strength is increased is not clear, it is considered that since the peel strength is related to the catalyst for producing polyethylene and the density, the crystal structure of polyethylene produced with the metallocene catalyst is affecting.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The layer (A) of the present invention is composed of a resin composition comprising 20 to 100% by weight of a specific amorphous polyolefin and 0 to 80% by weight of a crystalline polypropylene. (A) The specific amorphous polyolefin, which is one component of the layer, comprises 50% by weight or more of propylene and / or butene-1,
If necessary, a polyolefin copolymerized with an α-olefin having 2 to 8 carbon atoms excluding propylene and butene-1, wherein the amount of boiling n-heptane-insoluble matter is 60% by weight or less, preferably 50% by weight. These are: Except for propylene and butene-1 which are copolymer components, the carbon number is 2
8 as the α-olefin, ethylene, pentene-
Examples thereof include 1,4-methyl-1-pentene, hexene-1, heptene-1, and octene-1. These α-
The olefin can be used alone or in combination of two or more. When the content of propylene and / or butene-1 in the amorphous polyolefin is less than 50% by weight, it is difficult to form a film layer, and the mechanical strength and heat resistance are reduced.

Further, the amount of the boiling n-heptane insoluble content is 60
When the amount is more than the weight%, the flexibility and uniform stretchability of the film decrease. The proportion of the boiling n-heptane-insoluble component is 50 to 200 with respect to the weight of the amorphous polyolefin to be measured using a double tube Soxhlet extractor.
Using a double volume of n-heptane for several hours, usually 5 to 2 hours
The mixture is boiled under reflux for 4 hours and calculated from the weight ratio of the measurement sample before and after extraction with boiling n-heptane. Further, the specific amorphous polyolefin of the present invention is a polyolefin that exhibits substantially the same behavior as amorphous, and means a low-crystalline polyolefin having a crystallinity of 30% or less, usually 0.1 to 20%. And the density is 0.885 g / cm ³ or less, usually 0.85 g / cm ^3.
5 to 0.885 g / cm ³ . This crystallinity is determined by JI
Based on the density measured by the density gradient tube method of SK 7112, the density of 100% crystal of polypropylene was determined to be 0.936.
g / cm ^3, it is the value calculated density of amorphous as 0.855 g / cm ^3. The sample used for the density measurement is formed by sandwiching an amorphous polyolefin pellet between metal plates coated with Teflon, heating and compressing the sheet at 190 ° C., forming a sheet, and then allowing the sheet to cool at 23 ° C.

Specific examples of the amorphous polyolefin include:
Propylene homopolymer, butene-1 homopolymer, propylene / butene-1 copolymer, propylene component and / or butene-1 having a boiling n-heptane insoluble content of 60% by weight or less.
A propylene / ethylene copolymer having a component content of 50% by weight or more;
Original copolymer, propylene / hexene-1 / octene-1
Terpolymer of propylene / hexene-1 / 4-methylpentene-1, polybutene-1, butene-1 / ethylene copolymer, butene-1 / hexene-1
A ternary copolymer of octene-1 and a terpolymer of butene-1.hexene-1,4-methylpentene-1; When the amorphous polyolefin is a propylene / ethylene copolymer, the ethylene component content is 0.01 to 30.
%, Preferably 1 to 20% by weight.
When the content of the ethylene component is more than 30% by weight, the mechanical strength decreases. In the present invention, the amorphous polyolefin can be used alone or in combination of two or more.

The amorphous polyolefin used in the present invention is a raw material monomer comprising propylene and / or butene-1 and, if necessary, an α-olefin as a copolymer component,
It is produced by polymerizing in the presence or absence of hydrogen using a known polymerization catalyst system, for example, a catalyst system comprising a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. In addition, a commercially available amorphous polyolefin having the same composition and characteristics as the present invention can be used. Commercially available products include, for example, REXTA (REXTA) of the United States.
C) and Ube Lexen's Ubetak.

[0013] The crystalline polypropylene, which is another component optionally used in the layer (A), is mostly a boiling n-heptane-insoluble polypropylene having an isotactic structure, and is used for extrusion molding and injection molding. And commercially available crystalline polypropylene for blow molding and the like. The crystalline polypropylene may be a propylene homopolymer or a copolymer composed of propylene and another α-olefin, and usually has a density of 0.890 g / cm.
^Three or more can be used. As the α-olefin used for the copolymerization, except for propylene, an α-olefin having 2 to 8 carbon atoms, for example, ethylene, butene-1, pentene-1, 4-methyl-1-pentene, hexene-1,
Heptene-1, octene-1 and the like. Of these, ethylene and butene-1 are preferred.

Specific examples of the crystalline polypropylene include a propylene homopolymer, a propylene / ethylene random copolymer or a block copolymer containing 30% by weight or less, preferably 1 to 25% by weight of an ethylene component, 1
Propylene-butene-1 random copolymer or block copolymer, propylene-ethylene-butene ternary random copolymer or ternary block copolymer containing 20% by weight or less.

The production of crystalline polypropylene is not particularly limited, and it can be produced by a known method for producing crystalline polypropylene. For example, using a catalyst system in which a solid catalyst component comprising magnesium, titanium, a halogen atom and an electron donor, an organoaluminum compound, an alkoxy group-containing aromatic compound and, if necessary, an electron donating compound, a gas-phase one-stage It is produced by a method such as a synthesizing method, a slurry one-stage polymerization method, a gas-phase multi-stage polymerization method, and a slurry multi-stage polymerization method.

The amorphous polyolefin and the optionally used crystalline polypropylene include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters and acids. Derivatives such as anhydrides and derivatives of metal salts, unsaturated amides, amino compounds, glycidyl methacrylate, hydroxy methacrylate and the like may be modified by a known method using a twin-screw kneader or the like. Among these modified products, those modified with maleic anhydride and itaconic anhydride are preferably used.

The resin composition of the layer (A) of the present invention comprises an amorphous polyolefin alone or an amorphous polyolefin and a crystalline polypropylene, and the proportion of the amorphous polyolefin is 20 to 100% by weight, preferably 25% by weight. ~ 90% by weight
And the content of the crystalline polypropylene is 0 to 80% by weight, preferably 10 to 75% by weight. When the proportion of the amorphous polyolefin is less than 20% by weight, it is difficult to obtain flexibility and uniform stretchability. The amorphous polyolefin contributes to the flexibility of the laminated film and the uniformity of stretching, and the crystalline polypropylene contributes to increasing the mechanical strength such as heat resistance and tensile modulus of the laminated film.

The resin composition comprising the amorphous polyolefin and the crystalline polypropylene for the layer (A) is produced by a known method. For example, a kneader such as a kneader, a Banbury mixer, a roll, or a single-screw or twin-screw extruder may be used. It is manufactured by a method of heating and melting and kneading.

The polyethylene produced with the metallocene catalyst of the layer (B) can be obtained by a known production method. For example, a metallocene compound and an organic aluminum compound and / or
Alternatively, using a catalyst system consisting of a combination of ionic compounds, fluidized bed gas phase polymerization or stirring gas phase polymerization in an inert gas, slurry polymerization in an inert solvent, bulk polymerization using a monomer as a solvent, etc. Manufactured.

As the metallocene catalyst of the present invention, a combination of a metallocene compound and an organic aluminum compound and / or an ionic compound is used. Specific examples of the metallocene compound include dimethylsilyl (2,4-dimethylcyclopentadienyl) (3 ′, 5′-dimethylcyclopentadienyl) zirconium dichloride and dimethylsilyl (2,4-dimethylcyclopentadienyl) (3 ',
Silicon-bridged metallocene compounds such as 5'-dimethylcyclopentadienyl) hafnium dichloride; and indenyl-based bridged metallocene compounds such as ethylenebisindenylzirconium dichloride and ethylenebisindenylhafnium dichloride.

As the organoaluminum compound, a linear or cyclic polymer represented by the general formula (-Al (R) O-) n (R is a hydrocarbon group having 1 to 10 carbon atoms; Including those partially substituted with halogen atoms and / or RO groups, n is the degree of polymerization and is 5 or more, preferably 10 or more.
Specific examples include methylalumoxane, ethylalumoxane, isobutylethylalumoxane, and the like. Examples of other organoaluminum compounds include trialkylaluminum, dialkylhalogenoaluminum, and the like.

The ionic compound is represented by the general formula: C ⁺ .A
^- , C ⁺ is an oxidizing cation of an organic compound, an organometallic compound, or an inorganic compound, or a Bronsted acid comprising a Lewis base and a proton, and reacts with an anion of a metallocene ligand to form a metallocene cation. Can be generated. Specific examples thereof include an ionic compound of a tetrakis (pentafluorophenyl) borate anion and a triphenylcarbonium cation or a dialkylanilinium cation.

The polyethylene produced with the metallocene catalyst may be an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. Specific examples of the α-olefin having 3 to 10 carbon atoms include propylene, butene-1, pentene-1, hexene-1, 4-methyl-1-pentene, heptene-1,
Octene-1, nonene-1, decene-1 and the like. These α-olefins may be used alone or in combination of two or more.

The copolymer of ethylene and α-olefin may be a random copolymer or a block copolymer. The content of ethylene in the copolymer is 90 mol% or more, preferably 93 to 99.
9 mol%. When the amount of ethylene is less than 90 mol%, the mechanical strength decreases. Further, unless the object of the present invention is hindered, vinyl acetate, maleic acid, vinyl alcohol, methacrylic acid, methyl methacrylate, ethyl methacrylate, etc., in a range of 10 mol% or less of the whole copolymer,
It may be copolymerized.

The polyethylene used in the present invention is manufactured by using a metallocene catalyst, and has a density of 0.890-0.
935, preferably 0.895 to 0.930, and a molecular weight distribution of 2.2 to 5.5, preferably 2.2 to 2.0.
4.0. When the density and the molecular weight distribution are out of the above ranges, it becomes difficult to produce a good film, or the peel strength of the interface between the layer containing the amorphous polyolefin as the main component and the polyethylene layer of the laminated film is reduced. There is.

The resin composition of the layer (A) and / or the polyethylene of the layer (B) may contain, if necessary, known additives, antioxidants, and the like, as long as the properties of the present invention are not impaired.
Heat stabilizer, light stabilizer, ultraviolet absorber, antistatic agent, dispersant, chlorine scavenger, flame retardant, crystallization nucleating agent, antiblocking agent, slip agent, antifogging agent, release agent, pigment, organic substance filling Materials, inorganic fillers, neutralizers, lubricants, decomposers, metal deactivators, antifouling agents, antibacterial agents and other resins, thermoplastic elastomers, etc., can be added as long as the effects of the invention are not impaired. .

Examples of these additives include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol and 2,6-dicyclohexyl-4-ethylphenol. Organic phosphite antioxidants such as trioctyl phosphite and tristridecyl phosphite; and sulfur antioxidants such as dilauryl thiodipropionate and pentaerythritol tetralauryl thiopropionate. As a light stabilizer, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidine) -1,2,3,4- There are hindered amine stabilizers such as butanetetracarboxylate. Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers such as 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone, and 2,2 ′
-Methylene-bis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazole-2-
Yl) phenol]], and benzotriazole-based ultraviolet absorbers such as 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole.

Examples of the antistatic agent include nonionic antistatic agents such as poly (oxyethylene) alkylamine and poly (oxyethylene) alkylamide; cationic antistatic agents such as quaternary ammonium chloride and quaternary ammonium sulfate; There are anionic antistatic agents such as alkylsulfonates and alkylbenzenesulfonates. Ethylene bisoleic acid amide as a dispersant,
There are bisamide-based dispersants such as ethylenebisstearic acid amide, wax-based dispersants such as microcrystalline wax, and organic metal salt-based dispersants such as barium stearate, calcium stearate, and zinc stearate.

Examples of the flame retardant include phosphoric acid flame retardants such as tricresyl phosphate and ammonium phosphate, antimony trioxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, and red phosphorus. As the antiblocking agent, silica, natural zeolite,
Synthetic zeolite, kaolin, talc, silicone resin,
Examples include fine particles of silicone rubber, fused silica, melamine resin, acrylic resin, and hydrotalcite. As the slip agent, higher fatty acid amides such as lauric amide and oleic amide are suitable. Other resins that can be added include high-density polyethylene, low-density polyethylene, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, polyethylene wax, and petroleum. Resins, terpene resins, cumarone-indene resins, rosin resins and hydrogenated derivatives thereof. Examples of the thermoplastic elastomer include a styrene / butadiene / styrene block copolymer and a hydrogenated styrene / ethylene / butylene / styrene block copolymer;
There are an isoprene / styrene block copolymer and its hydrogenated styrene / ethylene / propylene / styrene block copolymer, ethylene propylene rubber, ionomer and the like.

The laminated film of the present invention is constituted by alternately laminating the (A) layer and the (B) layer, and the number of the laminated (A) and (B) layers is not particularly limited. It is preferred that the outermost layer, that is, at least one of the layers forming both outer surfaces, be constituted by the layer (B). For example, (B) / (A), (B) / (A) /
(B), (B) / (A) / (B) / (A), (B) /
(A) / (B) / (A) / (B).

In the present invention, the thickness of the layers (A) and (B) constituting the laminated film is not particularly limited, and can be arbitrarily selected according to the application. Usually, the thickness of each layer is in the range of 2 to 500 μm, preferably 3 to 100 μm. Further, the ratio of the thickness of the (A) layer to the thickness of the (B) layer is also
It is appropriately selected depending on the application. Usually, the thickness of the layer (A) is 20 to 99%, preferably 30 to 95%, more preferably 35 to 90% of the total thickness of the laminated film.
When the thickness of the (A) layer is smaller than the above lower limit, the flexibility and uniform stretchability of the laminated film may decrease. If the upper limit is exceeded, the mechanical strength of the laminated film will decrease.

The laminated film of the present invention can be produced by a known film production method. For example, a coextrusion lamination method, a lamination method, a dry lamination method, or the like can be used. Among these methods, a co-extrusion lamination method in which a film is melt-bonded at the time of film production is preferable. In this method, melt extrusion is performed using an extruder suitable for the number of layers, and the layers are laminated in a molten state by a known method such as a T-die method or an inflation method. It is a manufacturing method. Also, if necessary, the laminated film is a uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method,
The film is stretched by a multiaxial stretching method or another known stretching method. Usually, it is stretched at a surface stretching ratio of 1.1 to 30 times.
The polyethylene-based laminated film of the present invention has excellent stretching uniformity when stretched biaxially or multiaxially.

In the laminated film of the present invention, the layer (A) and the layer (B) are firmly adhered to each other by the coextrusion lamination method in which the layers are melt-bonded at the time of the production without using an adhesive. Peel strength is high. The peel strength is also high when the (A) layer and the (B) layer are bonded with an adhesive to form a laminated film.
At this time, specific examples of the adhesive that can be used include epoxy resin,
Thermosetting resin adhesive such as silicone resin, thermoplastic resin adhesive such as polyvinyl ether, acrylic resin, vinyl acetate-ethylene copolymer, polyamide resin hot melt adhesive, rubber adhesive such as nitrile rubber, etc. No.

The laminated film of the present invention can be subjected to a surface treatment for the purpose of improving printability, lamination and adhesive applicability. Examples of the surface treatment method include corona discharge treatment, plasma treatment, flame treatment, and acid treatment. Among these treatments, a plasma treatment, a flame treatment, and a corona discharge treatment, which can be performed continuously and can be easily performed before the winding step in the film production process, are preferable.

The laminated film of the present invention is laminated, cooled and solidified, subjected to a surface treatment if necessary, wound up, and wound up to the next step, for example, printing, laminating, tackifying, heat sealing, etc. A secondary processing step can also be performed.

The laminated film of the present invention is used in various fields because of its flexibility, high peel strength between the laminated films, and excellent transparency and uniformity of stretching. For example, industrial applications such as surface protection films and dicing films, decorative films, interior films such as tablecloths, aluminum evaporated films, medical supplies such as infusion bags,
There is a cushioning material or the like which is used by enclosing air. Among them, it is particularly suitable for a table cloth and a dicing film. Further, the laminated film of the present invention comprises (A) layer and (B)
Another thermoplastic resin layer, for example, nylon, ethylene-vinyl alcohol copolymer, polyester, or the like, may be inserted between the layers to improve the gas barrier properties.
Further, another polyolefin-based film can be laminated on the outer layer of the laminated film of the present invention.

[0037]

The present invention will be described below in detail with reference to examples and comparative examples. The characteristics described in the examples and comparative examples were measured by the following methods.

1) Determination of boiling n-heptane insoluble content About 2 g of amorphous polyolefin was placed in a dry tubular filter paper, weighed, set in a double tube Soxhlet extractor, and 150 g of n-heptane was obtained. Is placed in a Soxhlet vessel, heated and boiled under reflux for 10 hours to extract the dissolved components in the amorphous polyolefin. Thereafter, the tubular filter paper in which the n-heptane-insoluble portion remains is taken out, dried under reduced pressure until the weight becomes constant, and the weight is measured. The boiling n-heptane insoluble content is calculated from the weight ratio before and after the extraction of n-heptane.

2) Measurement of density The density was measured using a density gradient tube according to JIS K7112. A sample for measuring the density of the amorphous polyolefin was prepared by sandwiching an amorphous polyolefin pellet between metal plates coated with Teflon, heating and compressing the sheet at 190 ° C., forming a sheet, and then allowing the sheet to cool at 23 ° C. In addition, a sample for measuring the density of polyethylene produced with the metallocene catalyst was heat-treated at 100 ° C. for 1 hour at a strand of about 9 mm diameter extruded at 190 ° C. using an extruder, and then cooled to room temperature over 1 hour. Created.

3) Measurement of molecular weight distribution GPC 150CV manufactured by Waters Co., Ltd. was used. The column was PL Mixed B, the temperature was 135 ° C., and the solvent was obtained from the weight average molecular weight and the number average molecular weight measured using o-dichlorobenzene.

4) Measurement of Peeling Strength: From the three-layer laminated film (B) / (A) / (B), 25
A test piece having a width of 150 mm and a length of 150 mm was cut out. After stretching the end portion of this test piece by hand,
An adhesive tape was stuck and a part of the stretched portion was peeled off to obtain a film in which the intermediate layer (A) and the outer layer (B) were separated at the lamination interface. The peeled film portion was sandwiched between chucks of a tensile tester (AGS 500 manufactured by Shimadzu Corporation) to perform a tensile test, and the strength was defined as the peel strength.

5) Measurement of transparency Haze was measured according to ASTM D1003.

6) Measurement of stretchability Using an oil-based oil pen, a square sample having a length of 90 mm and a width of 90 mm was cut out from a laminated film in which grids were filled in grids at 10 mm intervals. Using a biaxial stretching machine BIX-703 type (manufactured by Iwamoto Seisakusho) at 50 ° C.
Simultaneously up to 100% vertically and horizontally at 10% / min 2
The film was axially stretched, heat-set at 100 ° C. for 5 minutes, and then taken out after cooling to room temperature. The shape of the mesh of the stretched laminated film was evaluated using a ruler. One in which the meshes were almost uniformly stretched was defined as uniform, and one in which the meshes were deformed was defined as deformation.

Example 1 The resin composition constituting the (A) layer had a propylene content of 6
5% by weight, butene-1 content 35% by weight copolymer,
Amorphous polyolefin having a boiling n-heptane insoluble content of 5% by weight and a crystallinity of 6% (trade name: Ubetack UT2780, manufactured by Ube Industries, density 0.86 g / cm ³ ) and a density of 0.
50/50 of 91 g / cm ³ crystalline polypropylene (trade name: F226D, manufactured by Grand Polymer Co., Ltd.)
Glycerin monostearate was added to 100 parts by weight of the mixture, and the mixture was melt-kneaded at a temperature of 200 ° C. for 30 minutes and then pelletized. The polyethylene produced using the metallocene catalyst constituting the layer (B) has a density of 0.918 g /
cm ³ , molecular weight distribution 2.8 (trade name UME manufactured by Ube Industries, Ltd.)
RIT 2040F) was used. Layer structure is (B) /
(A) / (B) using three extruders each having three independent layers and T dies connected to these extruders, respectively.
A melt three-layer co-extrusion is performed at a temperature of 190 ° C., and the thickness is 15 μm / 60 μm / 15 μm under the condition of a cooling roll temperature of 20 ° C.
Was formed into a three-layer laminated film. The peel strength, transparency and stretchability of the obtained laminated film were measured, and the results are shown in Table 1.

Comparative Example 1 A density of 0.940 g / cm ³ and a molecular weight distribution of 2.8 produced using a metallocene catalyst as the polyethylene of the (B) layer.
Example 1 was repeated except that polyethylene was used. The peel strength, transparency and stretchability of the obtained laminated film were measured, and the results are shown in Table 1.

Comparative Example 2 The density of 0.922 g / cm was used in place of polyethylene produced using a metallocene catalyst as the polyethylene of the layer (B).
³ low-density polyethylene (Ube Industries, Ltd., trade name F
222) was carried out in the same manner as in Example 1 except that the above-mentioned Example 222 was used. The peel strength, transparency and stretchability of the obtained laminated film were measured, and the results are shown in Table 1.

Comparative Example 3 A polyethylene having a density of 0.920 g / c was used in place of polyethylene produced using a metallocene catalyst as the polyethylene of the layer (B).
linear m ³ low-density polyethylene (Ube Industries, Ltd., trade name FS150A) except for using was performed in the same manner as in Example 1. The peel strength, transparency and stretchability of the obtained laminated film were measured, and the results are shown in Table 1.

Example 2 As the amorphous polyolefin of the resin composition constituting the layer (A), a copolymer having a propylene content of 85% by weight and an ethylene content of 15% by weight and having a boiling n-heptane insoluble content of 0% was used. (B) a non-crystalline polyolefin having a crystallinity of 2% (trade name: Ubetack UT2585, manufactured by Ube Industries, Ltd.) and a density of 0,7 as polyethylene produced using a metallocene catalyst constituting the layer (B). 904 g / cm
^3. Molecular weight distribution 2.8 (UMERIT, Ube Industries, Ltd.)
Except that 0540F) was used, the procedure was the same as in Example 1. The peel strength, transparency and stretchability of the obtained laminated film were measured, and the results are shown in Table 1.

[0049]

[Table 1]

[0050]

The amorphous polyolefin 20 to 100 in which the (A) layer has a propylene and / or butene-1 content of 50% by weight or more and a boiling n-heptane insoluble content of 60% by weight or less. % By weight and crystalline polypropylene 0
(B) layer comprising a metallocene-catalyzed polyethylene, (A)
The polyethylene-based laminated film in which the layer and the layer (B) are laminated has excellent peel strength at the lamination interface, transparency and uniformity of stretching.

Continued on the front page F term (reference) 4F100 AK03A AK04B AK04K AK07A AK09A AK62B AK66A AK67A AL05A BA02 BA10A BA10B BA16 GB08 GB90 JA07B JA11A JA12A JA13B JA20A JK06 JK08 JK13 JL00 JN01YY00A

Claims (2)

[Claims] An amorphous polyolefin 20 to 100 in which the layer (A) has a content of propylene and / or butene-1 of 50% by weight or more and a boiling n-heptane insoluble content of 60% by weight or less. % By weight and crystalline polypropylene 0
(B) layer comprising a metallocene-catalyzed polyethylene, (A)
A polyethylene-based laminated film, wherein a layer and a layer (B) are laminated. 2. The density of polyethylene produced with the metallocene catalyst constituting the layer (B) according to claim 1 is 0.89.
In the range of 0~0.935g / cm ^3, and a polyethylene-based laminate film according to claim 1, wherein the molecular weight distribution is characterized in that in the range of 2.2 to 5.5.