JP2000301677A - Polypropylene laminated film - Google Patents

Abstract

(57) [Summary] [Problem] To provide a polypropylene-based laminated film which is excellent in flexibility and hardly exudes low molecular weight substances when used at a temperature of 40 to 100 ° C. A laminated film comprising at least three layers, wherein the content of propylene and / or butene-1 is 50.
Amorphous polyolefin having a boiling n-heptane insoluble content of 60% by weight or less.
(A) a layer composed of a resin composition containing 0% by weight and 10 to 80% by weight of a crystalline polypropylene, and (B) a layer composed of a resin containing a polypropylene produced with a metallocene-based catalyst as constituent layers. A polypropylene-based laminated film whose outer layer is the layer (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved soft polypropylene-based laminated film having at least three layers. More specifically, the soft polypropylene-based laminated film of the present invention is a polypropylene-based laminated film containing a specific amorphous polypropylene in the inner layer and a polypropylene produced in both outer layers using a specific catalyst. This polypropylene-based laminated film is used for a surface protection film, a heat-sealing film, a sealant film, and the like.

[0002]

2. Description of the Related Art A laminated film comprising an inner layer containing an amorphous polyolefin having a propylene and / or butene-1 content of 50% or more and an outer layer containing crystalline polypropylene is known (Japanese Patent Application Laid-Open No. 6-218892). Etc.). This laminated film is excellent in flexibility, transparency, mechanical strength, etc., and is known as a useful substitute for a soft polyvinyl chloride film.

[0003]

The crystalline polypropylene used for the outer layer in this method has an inherently high flexural modulus, so that the flexibility of the laminated film may be insufficient for some applications. However, there has been a problem that whitening occurs on the bent surface during bending. In addition, when used at a temperature higher than room temperature, for example, at a temperature of 40 to 100 ° C., a low molecular weight material or an additive in an amorphous polyolefin used for an inner layer in a relatively short time may be a laminated film. There are also problems such as oozing on the surface, stickiness of the surface, and bleeding out.

[0004]

DISCLOSURE OF THE INVENTION The present invention has excellent flexibility, and when used at a temperature of 40 to 100.degree. C., has little bleeding of low molecular weight substances on the surface of the laminated film and has excellent transparency. It is an object to provide a polypropylene-based laminated film.

As a result of various studies, the present inventors have found that, as the inner layer of the laminated film, a layer composed of a resin composition in which a specific amorphous polyolefin and crystalline polypropylene are blended in a specific ratio is used, and both outer layers are used. The present inventors have found that the problem of the present invention can be solved by using a polypropylene produced by using a specific catalyst.

That is, the present invention relates to a laminated film comprising at least three layers, wherein the laminated film comprises propylene and / or butene.
20 to 90% by weight of an amorphous polyolefin and a crystalline polypropylene 10 having a content of 50% by weight or more and a boiling n-heptane insoluble content of 60% by weight or less.
(A) layer composed of a resin composition containing ８０80% by weight and a layer (B) composed of a resin containing polypropylene produced with a metallocene catalyst as constituent layers, and both outer layers are (B) layers. It is a polypropylene-based laminated film.

When polypropylene produced by using a metallocene catalyst is used for the outer layer, it is excellent in flexibility and low molecular weight substances and additives in the amorphous polyolefin hardly ooze on the outer layer surface of the laminated film. Although it is not clear, it is presumed to be due to narrow molecular chain length, narrow composition distribution, narrow tacticity distribution, crystallinity, etc. of the polypropylene produced by the metallocene catalyst.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The layer (A) used in the laminated film of the present invention is composed of a resin composition containing 20 to 90% by weight of a specific amorphous polyolefin and 10 to 80% by weight of crystalline polypropylene. In this specific amorphous polyolefin, 50% by weight or more is propylene and / or butene-1, and as a component other than propylene and butene-1, α-C 2 to C 8 excluding propylene and butene-1 is used. The olefin may be copolymerized and has a boiling n-heptane insoluble content of 60% by weight or less, preferably 50% by weight or less. 2-8 carbon atoms excluding propylene and butene-1
As α-olefins, ethylene, pentene-1,
4-methyl-1-pentene, hexene-1, heptene-
1, octene-1 and the like. These α-olefins can be used alone or in appropriate combination of two or more kinds. When the content of propylene and / or butene-1 in the amorphous polyolefin is less than 50% by weight, the mechanical strength becomes low, or it becomes difficult to form a film layer, and a good laminated film is formed. It becomes difficult to obtain.

Further, the amount of the boiling n-heptane insoluble content is 60
When the content is more than the weight%, the flexibility of the laminated film is likely to be insufficient, and when the film is bent, the bent surface becomes white. Incidentally, the boiling n-heptane insoluble content is determined by using a double-tube Soxhlet extractor, using n-heptane in an amount of 50 to 200 times the weight of the amorphous polyolefin to be measured, for several hours, usually for several hours. After boiling and refluxing for 5 to 24 hours to dissolve the components soluble in boiling n-heptane, the insolubles are separated by filtration and the weight of the sample before boiling n-heptane extraction and the weight of the remaining insolubles are determined. It is calculated from the weight ratio.

The amorphous polyolefin used in the present invention refers to a polyolefin that exhibits substantially the same behavior as amorphous, and has a degree of crystallinity of about 0 to 30%. The degree may be zero. Usually, the density of the amorphous polyolefin used is 0.885 g / cm ³ or less, preferably in the range of 0.855 to 0.885 g / cm ³ . Crystallinity is JIS K 711
Based on the density measured by the density gradient tube method of No. 2, the value is calculated assuming that the density of 100% crystal of polypropylene is 0.936 g / cm ³ and the density of amorphous is 0.855 g / cm ³ . The sample used for density measurement is sandwiched between Teflon-coated metal plates with amorphous polyolefin pellets,
The sheet is formed by heating and compressing at 190 ° C. to form a sheet, and then left to cool at 23 ° C.

Specific examples of the amorphous polyolefin include:
Propylene homopolymer having a boiling n-heptane insoluble content of 60% by weight or less, propylene / butene-1 copolymer, propylene / ethylene copolymer having a propylene component and / or butene-1 component content of 50% by weight or more Terpolymer of propylene / butene-1 / ethylene, terpolymer of propylene / hexene-1 / octene-1 and terpolymer of propylene / hexene-1 / 4-methylpentene-1 Butene-1 homopolymer, butene-1 · ethylene copolymer, butene-1 · hexene-1 · octene-1 terpolymer, butene-1 · hexene-1 ・ 4-methylpentene-1 Ternary copolymers and the like can be mentioned. When the amorphous polyolefin is a propylene / ethylene copolymer,
Those having an ethylene component content of 0.01 to 30% by weight, preferably 1 to 20% by weight are desirable. When the content of the ethylene component is more than 30% by weight, the mechanical strength decreases. In the present invention, the amorphous polyolefin may be used alone or in an appropriate combination of two or more.

The amorphous polyolefin used in the present invention can be produced by a known polyolefin production method. For example, a raw material monomer comprising propylene and / or butene-1 and an α-olefin as a copolymerization component used as required is used, for example, a catalyst system comprising a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. It is produced by polymerizing using a known polymerization catalyst system in the presence or absence of hydrogen. In addition, any commercially available amorphous polyolefin having the same composition and characteristics as the present invention can be used. As a commercially available product, for example, Huntsman (US)
ts Man) and Ubetac by Ube Industries, Ltd.

Crystalline polypropylene, which is another component of the layer (A), is a polypropylene having an isotactic structure which is mostly insoluble in boiling n-heptane, and is commercially available for extrusion molding, injection molding, blow molding and the like. Crystalline polypropylene can be used. This crystalline polypropylene may be a propylene homopolymer, or may be a copolymer composed of propylene and another α-olefin.
Those having a density of 0.890 g / cm ³ or more are used. As the α-olefin used for the copolymerization, an α-olefin having 2 to 8 carbon atoms excluding propylene, for example, ethylene, butene-1, pentene-1, 4-methyl-1-pentene, hexene-1, heptene- 1, octene-1 and the like. These α-olefins can be used alone or in appropriate combination of two or more kinds. Among these α-olefins, 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 is produced by a known method for producing crystalline polypropylene. For example, magnesium, titanium, a solid catalyst component comprising a halogen atom and an electron donor, an organoaluminum compound, an alkoxy group-containing aromatic compound,
If necessary, use a catalyst system to which an electron-donating compound is added,
It is produced by a method such as a gas-phase one-stage polymerization method, a slurry one-stage polymerization method, a gas-phase multi-stage polymerization method, a slurry multi-stage polymerization method, or the like.

Further, the above-mentioned amorphous polyolefin and crystalline polypropylene are prepared from unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters, acid anhydrides and metal salts. Such as derivatives, unsaturated amides, amino compounds, glycidyl methacrylate, hydroxy methacrylate, etc.
Those modified by a known method using a twin-screw kneader or the like may be used. Among these modified ones, those modified with maleic anhydride or itaconic anhydride are preferably used.

The resin composition constituting the layer (A) of the present invention contains 20 to 90% by weight, preferably 25 to 80% by weight of an amorphous polyolefin and 10 to 8% of a crystalline polypropylene.
0% by weight, preferably 20-75% by weight. When the proportion of the amorphous polyolefin is less than 20% by weight, the flexibility is reduced, and when the laminated film is bent, the folded surface may be whitened or the transparency may be lowered. On the other hand, if the content is more than 90% by weight, low molecular weight substances and the like in the amorphous polyolefin may ooze onto the surface of the laminated film.

The resin composition containing 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, a single-screw or twin-screw extruder, or the like is used. It is produced by a method of melting and kneading an amorphous polyolefin and a crystalline polypropylene with heat.

The polypropylene used in the layer (B) of the present invention is a propylene homopolymer, a block copolymer of propylene and an α-olefin or a random copolymer produced by a metallocene catalyst. In the present invention, a propylene homopolymer and a propylene / α-olefin block copolymer can be preferably used, and a mixture of a propylene homopolymer and a propylene / α-olefin block copolymer can also be preferably used. It is desirable that the polypropylene unit in these homopolymers or copolymers has high crystallinity and a high proportion of boiling n-heptane insolubles is high, and a proportion of boiling n-heptane insolubles is 90% by weight or more,
Preferably, it is 95% by weight or more of polypropylene.
This polypropylene has a melt flow rate (MFR) of 0.1 to 30 g / 10 min measured at 230 ° C. under a load of 2160 g according to ASTM-D1238.
Preferably it is 0.3 to 20 g / 10 min. Further, using gel permeation chromatography (GPC), the solvent was 1,2,4-trichlorobenzene, and the measurement temperature was 145.
The molecular weight distribution measured by a known method at a temperature of 1 ° C. and a flow rate of 1 ml / min is about 1.5 to 3.5.

The α-olefin copolymerized with propylene in the presence of a metallocene catalyst includes, for example, ethylene, butene-1, pentene-1, hexene-1, octane-1, decene-1, dodecene-1, 4-methyl-1-
Penten, 2-methyl-1-butene, dimethylpentene, vinylcyclopentene and the like can be mentioned. Usually, the amount of α-olefin in the copolymer is not more than 15 mol%.

When the proportion of the boiling n-heptane-insoluble component of the polypropylene used in the layer (B) is less than 90% by weight, low molecular weight substances and the like in the amorphous polyolefin may ooze out on the surface of the laminated film. There is. When the melt flow rate is out of the above range, it becomes difficult to obtain a good film.

The polypropylene used for the layer (B) is as follows:
It can be obtained by a known production method using a known metallocene catalyst. For example, propylene alone or propylene and an α-olefin as raw material monomers, a metallocene compound and an organic aluminum compound, an organic aluminum oxy compound, at least one cocatalyst component selected from Lewis acids or ionic compounds containing a boron atom, Can be polymerized in either a gas phase or a liquid phase using a so-called metallocene catalyst, and can be produced by any of a batch system, a semi-continuous system, and a continuous system. Usually, the polymerization temperature is -100 to 200C, and the polymerization pressure is normal pressure or ² to 50 kg / cm2.

As the metallocene compound, a compound having a cyclopentadienyl skeleton and containing one metal atom selected from transition metal atoms such as zirconium, titanium, hafnium, and vanadium is used. Specific examples of the metallocene compound include ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) zirconium (trifluoromethanesulfonate), and rac-dimethylsilylenebis {1- (2-methyl-). 4-phenylindenyl) {zirconium dichloride, rac-dimethylsilylenebis} 1- (2,7-dimethyl-4-ethylindenyl)} zirconium dichloride.

The above-mentioned organoaluminum compound includes:
Trimethylaluminum, triethylaluminum, tripropylaluminum, isoprenylaluminum and the like. Examples of the organic aluminum oxy compound include methylalumoxane, ethylalumoxane, isobutylethylalumoxane, and the like. Examples of the Lewis acid containing a boron atom include trifluoroboron, triphenylboron, tris (pentafluorophenyl)
And boron. Examples of the ionic compound containing a boron atom include triethylammonium tetra (phenyl) boron, tripropylammonium tetra (phenyl) boron, tributylammonium tetra (pentafluorophenyl) boron, and triphenylcarbeniumtetrakis (pentafluorophenyl). Boronate, bis [tri (n-butyl) ammonium] nonaborate and the like.

As the co-catalyst component used in combination with the metallocene compound, the organic aluminum compound, the organic aluminum oxy compound, the Lewis acid or ionic compound containing a boron atom may be used alone or in combination of two or more. Alternatively, the respective compounds may be used in appropriate combination. or,
The metallocene compound and the cocatalyst component may be used as a mixture, or a part or all of them may be used as a solid catalyst supported on a carrier.

Using the above metallocene catalyst,
(B) When producing the polypropylene used for the layer,
As the metallocene compound, the concentration of the transition metal atom in the metallocene compound in the polymerization system is used in the range of 10 ^-7 to 10 ^-4 gram atom / liter. When an organoaluminum compound and / or an organoaluminum oxy compound is used as a cocatalyst component, the atomic ratio (aluminum / transition metal) of aluminum in these compounds to the transition metal in the metallocene compound is in the range of 5 to 10,000. Is done. When a Lewis acid or ionic compound having a boron atom is used, the molar ratio of the metallocene compound to the Lewis acid or ionic compound having a boron atom is 0.01%.
Used in the range of 10 to 10.

The resin composition of the layer (A) and / or the polypropylene of the layer (B) may contain, if necessary, known additives, antioxidants, heat stabilizers, light Stabilizer, UV absorber, antistatic agent, dispersant, chlorine scavenger, flame retardant, crystallization nucleating agent, antiblocking agent,
Slip agents, antifogging agents, release agents, pigments, organic fillers, 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. There are 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 phosphate 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 is laminated (A)
There is no particular limitation on the number of layers of the layer and the layer (B), but it is composed of at least three layers, and both outer layers are layer (B). For example, (B) / (A) / (B), (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 ratio of the thickness of the (A) layer is smaller than the above lower limit, the flexibility of the laminated film is reduced, and cracks or whitening may occur on the bent surface. If it is larger than the above upper limit, low molecular weight substances and the like in the amorphous polyolefin may ooze onto the surface of the laminated film.

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.

The produced laminated film is stretched by a uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, a multiaxial stretching method, or other known stretching methods as required. Normal,
The film is stretched at an area stretching ratio of 1.1 to 30 times.

In the laminated film of the present invention, the layer (A) and the layer (B) are firmly adhered to each other by the co-extrusion lamination method in which the layers are melt-bonded at the time of the production without using an adhesive. Adhesion is high. It is needless to say that the layer (A) and the layer (B) can be bonded to each other with an adhesive to form a laminated film. At this time, specific examples of adhesives that can be used include epoxy resins,
Thermosetting resin adhesive such as silicone resin, thermoplastic resin adhesive such as polyvinyl ether, acrylic resin, vinyl acetate-ethylene copolymer, polyamide hot melt adhesive, rubber adhesive such as nitrile rubber and so on.

The laminated film of the present invention can be subjected to a surface treatment for the purpose of improving printability, lamination, and adhesive application properties. 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 it has little bleeding of low molecular weight substances and the like in amorphous polyolefin on the surface and is excellent in flexibility and transparency. For example, surface protection film, vehicle protection film, dicing film, decorative film, shrink film, stretch film, sealant film, heat welding film, heat bonding film, label film, building material film, adhesive base film, binding tape, It can be used for packaging films, electrical insulation films, agricultural films and the like.

The laminated film of the present invention is obtained by laminating another thermoplastic resin layer, for example, nylon, ethylene-vinyl alcohol copolymer, polyester, etc., between the layers (A) and (B). Also, the gas barrier property can be enhanced. Further, other polyolefin-based film or styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-isoprene-styrene block copolymer, the outer layer or the inner layer of the laminated film of the present invention, A film containing a thermoplastic elastomer such as styrene / ethylene / propylene / styrene block copolymer, ethylene propylene rubber, or ionomer can also be laminated.

[0040]

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

1) Measurement of boiling n-heptane insoluble content in amorphous polyolefin About 2 g of amorphous polyolefin was put into a dry cylindrical filter paper, and the weight thereof was measured. set. 150 g of n-heptane is placed in this Soxhlet container, heated and boiled under reflux for 10 hours,
Extract the dissolved components in the amorphous polyolefin. Thereafter, the tubular filter paper having the boiling n-heptane insoluble content remaining is taken out, dried under reduced pressure until a constant weight is obtained, and its weight is measured.
The boiling n-heptane insoluble content is calculated from the weight ratio before and after the extraction with boiling n-heptane according to equation (1).

## EQU00001 ## Boiling n-heptane insoluble matter (% by weight) = ((MN) / S) .times.100 (1) (wherein, M represents n-heptane insoluble matter after drying under reduced pressure and cylindrical filter paper) , N is the weight of the dried tubular filter paper, S
Is the weight of the amorphous polyolefin before boiling n-heptane extraction. The unit of weight is g. )

2) Measurement of melt flow rate of crystalline polypropylene According to ASTM D1238, temperature 230 ° C., load
It was measured at 2.16 kg. The unit is g / 10 min.

3) Measurement of exudation on the surface of the laminated film It is utilized that the haze value measured according to the method of ASTM D1003 increases when a low molecular weight material of amorphous polyolefin or the like exudes on the surface of the laminated film. The evaluation was made as follows. After measuring the haze of the laminated film, the laminated film was treated in a thermo-hygrostat at 70 ° C. and a relative humidity of 80% for 100 hours, the haze was measured again, and the haze change of the laminated film before and after this treatment was measured. Was evaluated by. It is determined that the larger the value of the haze after the processing is, the more the bleeding is.

4) Evaluation of Flexibility The flexibility was evaluated by bending the laminated film as described below and the state of the bent surface. The laminated film was bent at 180 degrees, sandwiched by a heating press in that state, and kept at 20 ° C. and a surface pressure of 5 MPa for 5 minutes. Thereafter, the folded laminated film was taken out, the folded portion was widened, and the occurrence of whitening was observed by visual observation. Those with almost no whitening were regarded as having good flexibility, and those with clearly observed whitening were regarded as having poor flexibility.

Example 1 As the resin composition constituting the (A) layer, a copolymer having a propylene content of 65% by weight and a butene-1 content of 35% by weight and having a boiling n-heptane insoluble content of 5% by weight was used. Amorphous polyolefin (made by Ube Industries, Ltd., trade name Ubetak UT)
2780, density 0.86 g / cm ³ ) and density 0.91 g
/ Cm ³ crystalline polypropylene (manufactured by Grand Polymer Co., Ltd., trade name: F221, melt flow rate (230
C) = 0.7 g / 10 min) in a weight ratio of 50/50, and melt-kneaded at a temperature of 200 ° C. to form pellets. On the other hand, the polypropylene constituting the layer (B) includes polypropylene produced by a metallocene-based catalyst (Achieve (A) manufactured by Exxon Chemical Co., Ltd.
CHIEVE), melt flow rate 6g / 10min)
It was used. The extruder was used at a temperature of 220 ° C. using an extruder to which three independent T dies were connected, using the (A) layer as the inner layer and the (B) layer as the raw materials for both outer layers.
At 0 ° C., the total thickness is 110 μm by the co-extrusion lamination method.
A three-layer laminated film having a thickness of μm was formed. The exudation and flexibility of the surface of the laminated film were evaluated, and the results are shown in Table 1.

Comparative Example 1 A method similar to that of Example 1 was used, except that a crystalline polypropylene (S105, manufactured by Grand Polymer Co., Ltd.) manufactured by a Ziegler-Natta catalyst was used instead of the polypropylene manufactured by the metallocene catalyst. This was performed to obtain a three-layer laminated film. The exudation and flexibility of the surface of the laminated film were evaluated, and the results are shown in Table 1.

Comparative Example 2 A laminated film was obtained in the same manner as in Example 1 except that the mixing ratio of the amorphous polyolefin and the crystalline polypropylene used in Example 1 was changed to 10/90 by weight. Was. The exudation and flexibility of the surface of the laminated film were evaluated, and the results are shown in Table 1.

Comparative Example 3 A laminated film was obtained in the same manner as in Example 1 except that the mixing ratio of the amorphous polyolefin and the crystalline polypropylene used in Example 1 was changed to 95/5 by weight. Was.
Evaluate the exudation and flexibility of this laminated film surface,
The results are shown in Table 1.

Example 2 (A) The amorphous polyolefin of the resin composition constituting the layer was prepared by mixing 85% by weight of propylene and 15% of ethylene.
The procedure was performed in the same manner as in Example 1 except that the copolymer was replaced by an amorphous polyolefin (trade name: Ubetack UT2585, manufactured by Ube Industries, Ltd.) having a weight% of a copolymer and a boiling n-heptane insoluble content of 0.7% by weight. Then, a decorative sheet was obtained. The exudation and flexibility of the surface of the laminated film were evaluated, and the results are shown in Table 1.

Example 3 The amorphous polyolefin of the resin composition constituting the layer (A) was prepared by mixing a propylene content of 65% by weight and a butene-1 content of 3
5% by weight of a copolymer having a boiling n-heptane insoluble content of 46%
A decorative sheet was obtained in the same manner as in Example 1 except that the weight% of the amorphous polyolefin (manufactured by Ube Industries, Ltd., density 0.88 g / cm ³ ) was used. The exudation and flexibility of the surface of the laminated film were evaluated, and the results are shown in Table 1.

[0051]

[Table 1]

[0052]

The polypropylene laminated sheet of the present invention has an inner layer comprising a layer containing 20 to 90% by weight of a specific amorphous polyolefin and 10 to 80% by weight of a crystalline polypropylene, and both outer layers having a metallocene catalyst. Consisting of polypropylene manufactured by This polypropylene-based laminated sheet is excellent in flexibility, and even when used at 40 to 100 ° C., the low molecular weight substances contained in the amorphous polyolefin are less likely to bleed onto the surface of the laminated sheet.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AK03A AK07A AK07B AK07C AK08A AK67 AL05A BA03 BA06 BA10B BA10C BA16 EH17 GB01 GB07 GB15 GB32 GB41 JA06B JA06C JA11A JA12A JB07A JK13 JK17 JL08B JL08 JL08N

Claims (2)

[Claims] 1. A laminated film comprising at least three layers, wherein the content of propylene and / or butene-1 is 5
0% by weight or more and an amorphous polyolefin having an boiling n-heptane insoluble content of 60% by weight or less.
(A) layer composed of a resin composition containing 90% by weight and 10 to 80% by weight of crystalline polypropylene and (B) composed of a resin containing polypropylene produced with a metallocene catalyst
), Wherein both outer layers are layers (B). 2. A melt flow rate (MF) of a polypropylene produced with a metallocene catalyst constituting the layer (B).
The polypropylene-based laminated film according to claim 1, wherein R) is 0.1 to 30 g / 10 minutes.