JPH11333980A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an extrusion laminated film consisting of an aluminum layer comprising an aluminum foil or an aluminized film and a linear low density polyethylene layer prepared by using a metallocene olefin polymerizing catalyst and good in the balance of pair aluminum bonding strength and the heat sealability of the low density polyethylene layer and a laminated film having a multilayered structure of three or more layers comprising these layers. SOLUTION: A laminated film consists of at least an aluminum layer (A) and the linear low density polyethylene layer (B) laminated to the single surface of the aluminum layer (A) and linear low density polyethylene forming the layer (B) is prepared by using a metallocene olefin polymerizing catalyst and has a density of 0.895-0.930 g/cm<3> and MFR (190 deg.C) of 0.1-100 g/10 min and the concn. of oxygen of linear low density polyethylene on the surface of the linear low density polyethylene layer (B) of the laminated film is 1.0-1.4 atom %.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film used for packaging foods such as dried foods and medical products.

[0002]

BACKGROUND ART Conventionally, snacks such as potato chips, confectionery such as biscuits, rice crackers, chocolates, and so-called dry foods such as powdered soup have a poor texture when eaten when they absorb moisture. Dried foods, such as potato chips, which have a large content, change their oil quality when exposed to oxygen gas, and therefore, packaging materials for dried foods are required to have excellent moisture-proof properties and oxygen gas barrier properties. In addition, pharmaceuticals are more demanding to prevent deterioration due to moisture absorption and gas. As such a packaging material, typically, a surface base material layer made of, for example, polyamide resin, polyethylene terephthalate resin or paper, a polyethylene layer mainly composed of high-pressure low-density polyethylene, aluminum foil, ethylene methacrylic acid An extruded laminate film composed of a sealant layer made of an acid copolymer such as a copolymer (EMAA) or an ionomer is used.

[0003] Acid copolymers such as EMAA and ionomer have excellent adhesiveness to aluminum foil, which is a property not found in conventional high-pressure low-density polyethylene.
It is often used for the above applications, but is expensive and has a problem of emitting odor. In addition, when an acid copolymer is used in producing the above-described extrusion laminated laminated film, a sufficient purge is required when changing the resin to another resin such as a high-pressure low-density polyethylene, and there is also a problem that a large amount of resin is lost. is there.

[0004] In order to solve the above-mentioned problems and the like, the present inventors have developed a linear chain prepared by using a metallocene-based olefin polymerization catalyst instead of an acid copolymer such as EMAA or ionomer as a resin for a sealant. Low-density polyethylene (M-LLDPE)
Adhesion between PE layer and aluminum foil, and M-LLD
The heat sealability of the PE layers was examined. In actual packaging, the adhesive force between the sealant layers may be more important than the adhesive force between the sealant layer and the aluminum layer. The present inventors have found a laminated film having a good balance between the properties and the adhesive strength to aluminum and having good quality as a dry food packaging material, and have completed the present invention.

[0005]

The object of the present invention is to provide an aluminum layer composed of an aluminum foil or an aluminum vapor-deposited film, and a linear low-density polyethylene layer prepared using a metallocene-based olefin polymerization catalyst. It is an object of the present invention to provide an extrusion-laminated laminated film having a good balance between the heat sealing properties of linear low-density polyethylene layers and a laminated film having a multilayer structure of three or more layers including these layers.

[0006]

The laminated film according to the present invention is a laminated film comprising at least an aluminum layer (A) and a linear low-density polyethylene layer (B) extrusion-laminated on one side of the aluminum layer (A). The linear low-density polyethylene forming the layer (B) is prepared using a metallocene-based olefin polymerization catalyst, and (i) the density (d;
ASTM D 1505) is 0.895 to 0.930 g / cm ³ , and (ii) melt flow rate (MFR; ASTM D 123).
8,190 ° C., load 2.16 kg) is 0.1 to 100 g / 10 min, and the laminated film has an oxygen concentration of linear low-density polyethylene alone on the surface of the linear low-density polyethylene layer (B). It is characterized in that it is 1.0 to 1.4 atomic%.

[0007] The laminated film according to the present invention further comprises a base material on the aluminum layer (A) opposite to the linear low density polyethylene layer (B) formed on one side of the aluminum layer (A). The layer (C) may be formed.

The first polyethylene layer (D) is further provided on the aluminum layer (A) opposite to the linear low density polyethylene layer (B) formed on one side of the aluminum layer (A). And the base layer (C) may be formed in this order, and the second polyethylene layer (D) may be formed on the linear low-density polyethylene layer (B).

Further, on the aluminum layer (A) opposite to the linear low-density polyethylene layer (B) formed on one side of the aluminum layer (A), a first base material layer ( C), the polyethylene layer (D) and the second base material layer (C) may be formed in this order.

In the present invention, the linear low-density polyethylene used for forming the linear low-density polyethylene layer (B) is a linear low-density polyethylene having a good balance between melt tension and fluidity and excellent moldability. When low density polyethylene is required, the following ethylene / α-olefin copolymer is preferred.

[0011] ethylene and α- having 4 to 20 carbon atoms
A copolymer with an olefin, wherein (i) the density (d) is in the range of 0.895 to 0.930 g / cm ³ ,
i) the melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg is in the range of 0.1 to 100 g / 10 minutes; and (iii) the melt tension at 190 ° C. (MT
(G)) and the melt flow rate (MFR (g / 10
) ^Satisfies the relationship expressed by MT> 2.0 × MFR ^-0.84 , and (iv) 190 ° C. of the molten polymer.
The fluidity index (F) defined by the shear rate when the shear stress reaches 2.4 × 10 ⁶ dyne / cm ² at
I (1 / sec)) and the melt flow rate (MFR (g /
10 min)), satisfying the relationship of FI> 75 × MFR, (v) n-decane soluble matter (W (% by weight)) at 23 ° C. and density (d (g / c)
m ³ )) and when MFR ≦ 10 g / 10 min: W <80 × exp (−100 (d−0.88)) + 0.1 When MFR> 10 g / 10 min: W <80 × (MFR −9) ^0.26 × exp (−100 (d−
0.88)) + 0.1, and (vi) the temperature (T) at the maximum peak position in the endothermic curve measured by the differential scanning calorimeter.
m (° C.)) and density (d (g / cm ³ )) satisfying the following relationship: Tm <400d-250.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The laminated film according to the present invention will be specifically described below. The laminated film according to the present invention includes at least an aluminum layer (A) and a linear low-density polyethylene layer (B) prepared using a metallocene-based olefin polymerization catalyst. Further, the laminated film according to the present invention has three or more layers having a base material layer (C) and a polyethylene layer (D) in addition to the aluminum layer (A) and the linear low-density polyethylene layer (B). It may have a multilayer structure.

Aluminum layer (A) As a material used for forming the aluminum layer (A), an aluminum foil or an aluminum vapor-deposited film is mainly used.

The thickness of the aluminum foil is usually 6 to 15 μm.
m. The substrate used for the aluminum-deposited film is not particularly limited as long as it is a material having a film-forming ability, and any polymer, paper, cellophane, or the like can be used.

As such a polymer, specifically,
High-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene
Acrylate copolymer, ethylene / vinyl alcohol copolymer, ionomer, polypropylene, poly-1
-Olefin polymers such as butene and poly-4-methyl-1-pentene; vinyl polymers such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate and polyacrylonitrile; nylon 6, nylon 66, nylon 10, Nylon 11, Nylon 12, Nylon 61
Polyamides such as polyethylene terephthalate (PET), polyethylene terephthalate / isophthalate, and polybutylene terephthalate (PBT); polyvinyl alcohol (PVA); and polycarbonate. In the film using these polymers, the molecules may be non-oriented or may be subjected to a uniaxial or biaxial stretching treatment.

Linear low-density polyethylene layer (B) The linear low-density polyethylene used for forming the above-mentioned linear low-density polyethylene layer (B) is prepared by reacting ethylene with ethylene in the presence of a metallocene-based olefin polymerization catalyst. 3 to 2 carbon atoms
Ethylene obtained by polymerizing α-olefin of
α-olefin copolymer.

Examples of the α-olefin having 3 to 20 carbon atoms used for copolymerization with ethylene include propylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1-pentene. , 1-octene, 1-decene, 1-dodecene and the like. Among them, those having 3 to 10 carbon atoms
Α-olefins, especially α-olefins having 4 to 8 carbon atoms, are preferred.

The α-olefin as described above can be used alone,
Alternatively, two or more kinds can be used in combination. The linear low-density polyethylene used in the present invention has a constitutional unit derived from ethylene of 50% by weight or more and less than 100% by weight, preferably 75-99% by weight, more preferably 7% by weight.
It is present in an amount of from 5 to 95% by weight, particularly preferably from 83 to 95% by weight, in which the constituent units derived from α-olefins having 3 to 20 carbon atoms are up to 50% by weight, preferably from 1 to 25%.
%, More preferably from 5 to 25% by weight, particularly preferably from 5 to 17% by weight.

The composition of the linear low-density polyethylene is usually determined by measuring the ¹³ C-NMR spectrum of a sample in which about 200 mg of the linear low-density polyethylene is uniformly dissolved in 1 ml of hexachlorobutadiene in a sample tube of 10 mmφ. It is determined by measuring at a temperature of 120 ° C., a measurement frequency of 25.05 MHz, a spectrum width of 1500 Hz, a pulse repetition time of 4.2 sec, and a pulse width of 6 μsec.

The linear low-density polyethylene used in the present invention has a density (ASTM D 1505) of 0.895 to 0.930.
g / cm ³ , preferably 0.895 to 0.910 g / c
m is ^3. When a linear low-density polyethylene having a density in the above-mentioned range is used, an extruded laminate having a good balance between the adhesiveness to the aluminum layer (A) and the heat sealing property between the linear low-density polyethylene layers (B). -A laminated film can be prepared.

The density is 2.16 at 190 ° C.
The extruded strand obtained at the time of melt flow rate (MFR) measurement under a kg load is heat-treated at 100 ° C. for 1 hour,
After slowly cooling to room temperature over time, the measurement is performed using a density gradient tube.

The melt flow rate of this linear low density polyethylene (MFR; ASTM D1238, 190 ° C., load
2.16 kg) is usually 0.1 to 100 g / 10 min, preferably 1 to 50 g / 10 min, more preferably 5 to 20 g / 1.
It is in the range of 0 minutes.

The linear low-density polyethylene as described above is disclosed, for example, in JP-A-6-9724 and JP-A-6-7-1.
No. 36195, JP-A-6-136196, JP-A-6-207057, etc., in the presence of a so-called metallocene-based olefin polymerization catalyst containing a metallocene catalyst component, ethylene and carbon atoms of 3 to 20
And α-olefins.

Such a metallocene catalyst generally has at least one ligand having a cyclopentadienyl skeleton.
Metallocene catalyst component (a1) comprising a transition metal compound of Group IVB of the periodic table, an organoaluminum oxy compound catalyst component (b), and, if necessary, a particulate carrier (c), an organoaluminum compound catalyst component ( d), formed from the ionized ionic compound catalyst component (e).

The metallocene catalyst component (a1) preferably used in the present invention is a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton. Examples of such a transition metal compound include a transition metal compound represented by the following general formula [I].

ML ¹ _x ... [I] In the formula, x is the valence of the transition metal atom M. M is a transition metal atom selected from Group IVB of the periodic table, and specifically, zirconium, titanium, and hafnium. Among them, zirconium is preferred.

L ¹ is a ligand which coordinates to the transition metal atom M, and at least one of these ligands L 1
¹ is a ligand having a cyclopentadienyl skeleton. The ligand L ¹ having a cyclopentadienyl skeleton coordinated to the transition metal atom M as described above, specifically, cyclopentadienyl group, alkyl-substituted Shikuropentaji such as a methyl group, an ethyl group Examples include an enyl group, an indenyl group, a 4,5,6,7-tetrahydroindenyl group, a fluorenyl group and the like. These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.

When the transition metal compound represented by the above general formula [I] contains two or more groups having a cyclopentadienyl skeleton, two of the groups having a cyclopentadienyl skeleton are ethylene And a substituted silylene group such as an alkylene group such as propylene, a silylene group or a dimethylsilylene group or a methylphenylsilylene group.

As the organoaluminum oxy compound catalyst component (b), aluminoxane is preferably used. Specifically, methyl aluminoxane, ethyl aluminoxane, methyl ethyl aluminoxane having a repeating unit represented by the formula -Al (R) O-, wherein R is an alkyl group, usually having about 3 to 50 Are used.

These aluminoxanes can be prepared by conventional methods. The fine-grained carrier (c) used as necessary in the preparation of the catalyst for olefin polymerization is an inorganic or organic compound and usually has a particle size of 10 to 300 μm.
And preferably 20 to 200 μm in the form of granules or fine particles.

As the inorganic carrier, a porous oxide is preferable. Specifically, SiO ₂ , Al ₂ O ₃ , MgO, Zr
O ₂ and TiO ₂ can be exemplified. As the organoaluminum compound catalyst component (d) optionally used in the preparation of the olefin polymerization catalyst, specifically,
Examples thereof include trialkylaluminums such as trimethylaluminum, dialkylaluminum halides such as dimethylaluminum chloride, and alkylaluminum sesquihalides such as methylaluminum sesquichloride.

Examples of the ionized ionic compound catalyst component (e) include triphenylboron, MgCl ₂ and Al ₂ described in US Pat. No. 5,321,106.
Lewis acids such as O ₃ and SiO ₂ —Al ₂ O ₃ ; ionic compounds such as triphenylcarbenium tetrakis (pentafluorophenyl) borate; carborane compounds such as dodecaborane and bis-n-butylammonium (1-carbedodeca) borate Is mentioned.

The linear low-density polyethylene used in the present invention can be mixed with ethylene under various conditions in a gas phase or a slurry or solution liquid phase in the presence of the above-mentioned olefin polymerization catalyst. It can be obtained by copolymerizing an α-olefin having 3 to 20 carbon atoms.

In the present invention, as the linear low-density polyethylene used for forming the linear low-density polyethylene layer (B), a linear low-density polyethylene having a particularly good balance between melt tension and fluidity and excellent moldability is used. When low-density polyethylene is required, the following ethylene / α-olefin copolymer (linear low-density polyethylene) is preferred.

Ethylene and α-C 4 -C 20
A copolymer with an olefin, wherein (i) the density (d) is in the range of 0.895 to 0.930 g / cm ³ ,
i) the melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg is in the range of 0.1 to 100 g / 10 minutes; and (iii) the melt tension at 190 ° C. (MT
(G)) and the melt flow rate (MFR (g / 10
) ^Satisfies the relationship expressed by MT> 2.0 × MFR ^-0.84 , and (iv) 190 ° C. of the molten polymer.
The fluidity index (F) defined by the shear rate when the shear stress reaches 2.4 × 10 ⁶ dyne / cm ² at
I (1 / sec)) and the melt flow rate (MFR (g /
10 min)), satisfying the relationship of FI> 75 × MFR, (v) n-decane soluble matter (W (% by weight)) at 23 ° C. and density (d (g / c)
m ³ )) and when MFR ≦ 10 g / 10 min: W <80 × exp (−100 (d−0.88)) + 0.1 When MFR> 10 g / 10 min: W <80 × (MFR −9) ^0.26 × exp (−100 (d−
0.88)) + 0.1, and (vi) the temperature (T) at the maximum peak position in the endothermic curve measured by the differential scanning calorimeter.
m (° C.)) and density (d (g / cm ³ )) satisfying the following relationship: Tm <400d-250.

In the ethylene / α-olefin copolymer, the constituent unit derived from ethylene is 65 to 99% by weight, preferably 70 to 98% by weight, more preferably 75% by weight.
Present in an amount of up to 96% by weight and having from 4 to 20 carbon atoms.
The constituent units derived from olefins are from 1 to 35% by weight, preferably from 2 to 30% by weight, more preferably from 4 to 2% by weight;
It is present in an amount of 5% by weight.

The α-olefin having 4 to 20 carbon atoms specifically includes 1-butene, 1-pentene, 1-pentene,
Hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-
Octadecene, 1-eicosene and the like can be mentioned.

Such an ethylene / α-olefin copolymer has a density (ASTM D 1505) of 0.895 to 0.930.
g / cm ³ , preferably 0.895 to 0.910 g / c
m ³ .

Further, the melt flow rate of this ethylene / α-olefin copolymer (ASTM D1238, 190 ° C., 2.16 k
g load) is 0.1 to 100 g / 10 min, preferably 1
５０50 g / 10 min, more preferably 5-20 g / 10 min.

This ethylene / α-olefin copolymer has a melt tension at 190 ° C. (MT (g)) and a melt flow rate (MFR (g / 10 minutes)) of MT> 2.0 × MFR ^-0.84 It preferably satisfies the relationship expressed by MT> 2.2 × MFR- ^0.84, more preferably MT> 2.5 × MFR- ^0.84 .

Such an ethylene / α-olefin copolymer has a high melt tension for its molecular weight and has good moldability. The ethylene / α-olefin copolymer used in the present invention has a fluidity index defined by a shear rate when the stress at 190 ° C. of the molten polymer reaches 2.4 × 10 ⁶ dyne / cm ^2. (FI (1 / sec)) and the melt flow rate (MFR (g / 10 minutes)) satisfy the relationship of FI> 75 × MFR, preferably FI> 80 × MFR, and more preferably FI> 85 × MFR. ing.

In general, an ethylene / α-olefin copolymer having a narrow composition distribution has a narrow molecular weight distribution and therefore has low fluidity and low FI. Ethylene used in the present invention
Since the α-olefin copolymer satisfies the above-described relationship between FI and MFR, low stress is maintained up to a high shear rate, and moldability is good.

The ethylene / α-olefin copolymer used in the present invention has an n-decane soluble content (W
(Weight%)) and density (d (g / cm ³ ))
When ≦ 10 g / 10 min: W <80 × exp (−100 (d−0.88)) + 0.1 Preferably, W <60 × exp (−100 (d−0.8
8)) + 0.1 More preferably, W <40 × exp (−100 (d−0.8
8)) + 0.1 When MFR> 10 g / 10 min: W <80 × (MFR-9) ^0.26 × exp (−100 (d−
0.88)) + 0.1 is satisfied.

It can be said that such an ethylene / α-olefin copolymer having a small n-decane soluble matter (W) has a narrow composition distribution. The ethylene / α-olefin copolymer used in the present invention has a temperature (Tm) at the maximum peak position in an endothermic curve measured by a differential scanning calorimeter (DSC).
(° C.)) and density (d (g / cm ³ )) are Tm <400 × d-250, preferably Tm <450 × d-297, more preferably Tm <500 × d-344, and particularly preferably Tm <550. × d-391.

The ethylene / α-olefin copolymer satisfying such a relationship has a lower Tm with respect to the density, and thus has a lower density than the ethylene / α-olefin copolymer which does not satisfy the above relationship even at the same density. Then, the heat sealability is excellent.

Such an ethylene / α-olefin copolymer includes, for example, a bidentate coordination in which two groups selected from (a2) a specific indenyl group and a substituent thereof are bonded via a lower alkylene group. A compound of a transition metal of Group IVB of the Periodic Table or a compound of a transition metal of Group IVB of the Periodic Table having a specific substituted cyclopentadienyl group as a ligand, (b) an organoaluminumoxy compound, c) ethylene and an α-olefin having 4 to 20 carbon atoms in the presence of a particulate carrier and, if necessary, (d) an olefin polymerization catalyst formed from an organoaluminum compound; Is 0.895 to 0.930 g / cm ³
It can be produced by copolymerizing such that

The olefin polymerization catalyst and each catalyst component will be described below. (A2) a compound of a transition metal of Group IVB of the periodic table having a bidentate ligand in which two groups selected from a specific indenyl group or a substituent thereof are bonded via a lower alkylene group, or a specific substitution A transition metal compound of Group IVB of the Periodic Table having a cyclopentadienyl group as a ligand (hereinafter sometimes referred to as “component (a2)”) is specifically represented by the following formula (II): The transition metal compound represented.

ML ² _x ... (II) (wherein, M represents a transition metal atom selected from Group IVB of the periodic table, and L ² represents a ligand coordinated to the transition metal atom. ligand L ² of at least two of is a substituted cyclopentadienyl group having 2 to 5 only substituents selected from methyl and ethyl groups, ligands other than the substituted cyclopentadienyl group L ² has 1 carbon atom
To 12 hydrocarbon groups, alkoxy groups, aryloxy groups,
A halogen atom, a trialkylsilyl group or a hydrogen atom, and x represents the valence of the transition metal atom M. In the general formula (II), M represents a transition metal atom selected from Group IVB of the periodic table, and specifically, is zirconium, titanium or hafnium, and preferably zirconium.

L ² represents a ligand coordinated to the transition metal atom M, and at least two of the ligands L ² have a substituent selected from a methyl group and an ethyl group of 2 to 5
Substituted cyclopentadienyl groups, each of which may be the same or different. This substituted cyclopentadienyl group is preferably a cyclopentadienyl group having 2 to 3 substituents, more preferably a disubstituted cyclopentadienyl group, and 1,3-substituted cyclopentadienyl group. Particularly preferred is an enyl group. In addition, each substituent may be the same or different.

In the above formula (II), the ligand L ² other than the substituted cyclopentadienyl group coordinated to the transition metal atom M is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, An aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and the like.
Methyl group, ethyl group, n-propyl group, isopropyl group,
alkyl groups such as n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group and decyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; An aryl group such as a phenyl group and a tolyl group; and an aralkyl group such as a benzyl group and a neophyl group can be exemplified.

Examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, t-butoxy, pentoxy, hexoxy, octoxy and the like. Can be exemplified.

Examples of the aryloxy group include a phenoxy group. A halogen atom is fluorine,
Chlorine, bromine and iodine. Examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a triphenylsilyl group.

As the transition metal compound represented by the general formula (II), specifically, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (diethylcyclopentadienyl) zirconium dichloride, bis (methyl) Ethylcyclopentadienyl) zirconium dichloridebis (dimethylethylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dibromide, bis (dimethylcyclopentadienyl) zirconium methoxy chloride, bis (dimethylcyclopentadiene Enyl) zirconium ethoxycyclolide, bis (dimethylcyclopentadienyl) zirconium butoxycyclolide, bis (dimethylcyclopentadienyl) zirconium diethoxide, (Lopentadienyl) zirconium methyl chloride, bis (dimethylcyclopentadienyl) zirconium dimethyl, bis (dimethylcyclopentadienyl) zirconium benzyl chloride, bis (dimethylcyclopentadienyl) zirconium dibenzyl, bis (dimethylcyclopentadienyl) zirconium Phenyl chloride, bis (dimethylcyclopentadienyl) zirconium hydride chloride and the like can be mentioned.

In the above examples, disubstituted cyclopentadienyl ring includes 1,2- and 1,3-substituted, and tri-substituted cyclopentadienyl ring includes 1,2,3- and 1,2,4-substituted. Including the body. In the present invention,
In the above zirconium compound, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can be used.

Among these transition metal compounds represented by the general formula (II), bis (1,3-dimethylcyclopentadienyl) zirconium dichloride and bis (1,3-diethylcyclopentadienyl) zirconium dichloride ,
Bis (1-methyl-3-ethylcyclopentadienyl) zirconium dichloride is particularly preferred.

The organoaluminum oxy compound (b) (hereinafter sometimes referred to as “component (b)”) may be a conventionally known benzene-soluble aluminoxane, or disclosed in JP-A-2-276807. It may be a benzene-insoluble organic aluminum oxy compound as disclosed in the gazette.

Conventionally known aluminoxanes are prepared, for example, by contacting an organoaluminum compound as described below with water such as adsorbed water, water of crystallization, ice, steam, or the like, It can be produced by reacting tin oxide.

The particulate carrier (c) (hereinafter sometimes referred to as “component (c)”) is an inorganic or organic compound having a particle size of 10 to 300 μm, preferably 20 to 2 μm.
A 00 μm granular or fine solid is used. Among them, a porous oxide is preferable as the inorganic compound carrier, and specifically, SiO ₂ , Al ₂ O ₃ , MgO, Z
rO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO,
ThO ₂ or the like or a mixture thereof, for example, SiO ₂ -M
gO, SiO ₂ -Al ₂ O ₃ , SiO ₂ -TiO ₂ , SiO _{2
-V 2 O 5, SiO 2 -Cr} 2 O 3, SiO 2 -TiO 2 -Mg
O and the like can be exemplified. Among them, those containing at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ as a main component are preferable.

The above inorganic oxide contains a small amount of Na ₂ C
O ₃ , K ₂ CO ₃ , CaCO ₃ , MgCO ₃ , Na ₂ SO
₄ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KNO ₃ , Mg
(NO ₃ ) ₂ , Al (NO ₃ ) ₃ , Na ₂ O, K ₂ O, Li
_It may contain carbonate, sulfate, nitrate and oxide components such as ₂ O.

The properties of the fine particle carrier made of such an inorganic compound differ depending on the kind and the production method, but the fine particle carrier preferably used in the present invention has a specific surface area of 5%.
0 to 1000 m ² / g, preferably 100 to 700 m ²
/ G, and the pore volume is desirably 0.3 to 2.5 cm ³ / g. The finely divided carrier may be used as needed.
It is used by baking at 00 to 1000 ° C, preferably 150 to 700 ° C.

As the organic compound carrier, α-olefins having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene, 4-methyl-1-pentene and the like (co)
Examples thereof include a polymer or a polymer or copolymer containing vinylcyclohexane or styrene as a main component.

The olefin polymerization catalyst used in the production of the ethylene / α-olefin copolymer comprises the component (a)
2), formed from component (b) and component (c),
If necessary, (d) an organoaluminum compound may be used.

As the (d) organoaluminum compound used as required (hereinafter sometimes referred to as “component (d)”), for example, an organoaluminum compound represented by the following general formula (III) is exemplified. be able to.

R ¹ _n AlX _3-n (III) (wherein, R ¹ is a hydrocarbon group having 1 to 12 carbon atoms, X is a halogen atom or a hydrogen atom, and n is 1 to 3)
3. In the above general formula (III), R ¹ has 1 to 12 carbon atoms.
A hydrocarbon group such as an alkyl group, a cycloalkyl group or an aryl group, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, and an octyl group. Group, cyclopentyl group, cyclohexyl group, phenyl group, tolyl group and the like.

Specific examples of such an organoaluminum compound include the following compounds. Trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, tri-2-ethylhexylaluminum; alkenylaluminum such as isoprenylaluminum; dimethylaluminumchloride, diethylaluminumchloride, diisopropylaluminumchloride, diisobutyl Dialkyl aluminum halides such as aluminum chloride and dimethyl aluminum bromide; alkyl aluminum sesquihalides such as methyl aluminum sesquichloride, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride and ethyl aluminum sesquibromide; methyl aluminum Umujikurorido, ethylaluminum dichloride, isopropyl aluminum dichloride,
Alkylaluminum dihalides such as ethylaluminum dibromide; alkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride.

Further, as the organoaluminum compound (d), a compound represented by the following general formula (IV) can be used. R in ^{_{1 n AlY 3-n ··· (}} IV) ( wherein, R ¹ represents the same hydrocarbon and R ¹ in the general formula (III), Y is -OR ² group, -OSiR ³ ₃ group , -OA
lR ⁴ ₂ group, -NR ⁵ ₂ group, -SiR ⁶ ₃ group or -N
(R ⁷⁾ AlR indicates ⁸ ₂ group, n is 1 to 2, R ^2,
R ³ , R ⁴ and R ⁸ are a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group, etc., and R ⁵ is a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a phenyl group, a trimethylsilyl group. And R ⁶ and R ⁷ are a methyl group, an ethyl group or the like. ) Among such organoaluminum compounds, R ¹ _nA
l (OAlR ⁴ ₂₎ compounds represented by _3-n, e.g.
(C ₂ H ₅ ) ₂ AlOAl (C ₂ H ₅ ) ₂ , (iso-C ₄ H ₉ ) ₂ A
_{lOAl (iso-C 4 H 9} ) 2 and the like are preferable.

[0068] Among the organic aluminum compound represented by the general formula (III) and (IV), is preferably a compound represented by the general formula R ¹ ₃ Al, especially compounds wherein R ¹ is isoalkyl group.

In producing the ethylene / α-olefin copolymer, the components (a2) and (b) as described above are used.
And a catalyst prepared by contacting component (c) and, if necessary, component (d).

The contact of each of the above components can be carried out in an inert hydrocarbon solvent. Specific examples of the inert hydrocarbon medium used for preparing the catalyst include propane, butane, pentane, hexane, heptane and octane. , Decane, dodecane, kerosene, etc .; aliphatic hydrocarbons; cyclopentane, cyclohexane, methylcyclopentane, etc .; alicyclic hydrocarbons; benzene, toluene, xylene, etc., aromatic hydrocarbons; ethylene chloride, chlorobenzene, dichloromethane, etc. Examples thereof include halogenated hydrocarbons and mixtures thereof.

The catalyst used in the production of the ethylene / α-olefin copolymer is prepared by the above-mentioned components (a2), (b), (c) and, if necessary, in the presence of component (d). Alternatively, a prepolymerized catalyst obtained by prepolymerizing an olefin may be used. The prepolymerization is carried out by introducing an olefin into an inert hydrocarbon solvent in the presence of the above components (a2), (b), (c) and, if necessary, (d). be able to.

The olefin used in the prepolymerization includes ethylene and the same olefin having 4 to 4 carbon atoms.
20 α-olefins and the like. Of these, ethylene or a combination of ethylene and an α-olefin used in the polymerization is particularly preferred.

The prepolymerization can be carried out either in a batch system or a continuous system, and can be carried out under reduced pressure, normal pressure or increased pressure. In the prepolymerization, the intrinsic viscosity [η] measured in decalin at least at 135 ° C. is in the range of 0.2 to 7 dl / g, preferably 0.5 to 5 dl / g in the presence of hydrogen. It is desirable to produce a polymer.

The ethylene / α-olefin copolymer is prepared by adding ethylene to the above-mentioned copolymer having 4 to 2 carbon atoms in the presence of the above-mentioned olefin polymerization catalyst or prepolymerization catalyst.
It can be obtained by copolymerization with 0 α-olefin.

In the present invention, the copolymerization of ethylene with an α-olefin is carried out in a gas phase or in a slurry liquid phase. In slurry polymerization, an inert hydrocarbon may be used as a solvent, or an olefin itself may be used as a solvent.

Specific examples of the inert hydrocarbon solvent used in the slurry polymerization include aliphatic hydrocarbons such as butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane and octadecane; cyclopentane and methylcyclopentane , Cyclohexane, cyclooctane and other alicyclic hydrocarbons; benzene, toluene, xylene and other aromatic hydrocarbons; gasoline, kerosene,
And petroleum fractions such as light oil. Among these inert hydrocarbon media, aliphatic hydrocarbons, alicyclic hydrocarbons, petroleum fractions and the like are preferred.

In carrying out the slurry polymerization method or the gas phase polymerization method, the olefin polymerization catalyst or the prepolymerization catalyst as described above is usually used in a concentration of 10 ⁻⁸ to 10 ⁻ as a transition metal atom concentration in the polymerization reaction system. It is desirably used in an amount of ³ gram atoms / liter, preferably 10 ^-7 to 10 ^-4 gram atoms / liter.

At the time of the main polymerization, the same organic aluminum oxy compound and / or organic aluminum compound (d) as the component (b) may be added. At this time, the atomic ratio (Al / M) of the aluminum atom (Al) derived from the organic aluminum oxy compound and the organic aluminum compound to the transition metal atom (M) derived from the transition metal compound (a2) is 5 to 300. , Preferably 10 to 20
0, more preferably 15 to 150.

When performing the slurry polymerization method, the polymerization temperature is usually in the range of -50 to 100 ° C., preferably 0 to 90 ° C. When performing the gas phase polymerization method, the polymerization temperature is: Usually, it is in the range of 0 to 120 ° C, preferably 20 to 100 ° C.

The polymerization pressure is usually from normal pressure to 100 kg /
cm ² , preferably ² to 50 kg / cm ² under pressure, and the polymerization can be carried out in any of a batch system, a semi-continuous system, and a continuous system.

Further, the polymerization can be carried out in two or more stages having different reaction conditions. In the present invention,
In the linear low-density polyethylene as described above, if necessary, conventionally known slip agent, anti-blocking agent,
Antistatic agent, weather stabilizer, heat stabilizer, antifogging agent, pigment,
Additives such as dyes and fillers can be blended within a range that does not impair the purpose of the present invention.

The thickness of the linear low-density polyethylene layer (B) in the laminated film according to the present invention is usually from 10 to 50.
μm, preferably 15 to 30 μm. The linear low-density polyethylene layer (B) is usually used as a sealant layer, but can also be used as an intermediate layer in a laminated film.

Base Material Layer (C) In the laminated film according to the present invention, the base material layer (C) may be formed, and the base material used for the base material layer (C) is a film-forming material. The material is not particularly limited as long as it has a function, and any polymer, paper, cellophane, or the like can be used. An anchor coating agent such as a urethane anchor coating agent may be applied to the surface of the base material layer (C).

As such a polymer, specifically,
High-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene
Acrylate copolymer, ethylene / vinyl alcohol copolymer, ionomer, polypropylene, poly-1
-Olefin polymers such as butene and poly-4-methyl-1-pentene; vinyl polymers such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate and polyacrylonitrile; nylon 6, nylon 66, nylon 10, Nylon 11, Nylon 12, Nylon 61
Polyamides such as polyethylene terephthalate (PET), polyethylene terephthalate / isophthalate, and polybutylene terephthalate (PBT); polyvinyl alcohol (PVA); and polycarbonate. Films using these polymers may be non-oriented, but may be subjected to uniaxial or biaxial stretching. The surface of the film may be coated with polyvinylidene chloride, or metals such as aluminum and silicon may be deposited.

When paper is used as the base material, the above polymer may be coated on the surface opposite to the surface in contact with the polyethylene layer (D), or a film using the above polymer may be laminated. May be.

The thickness of the substrate layer (C) in the laminated film according to the present invention is usually 10 to 30 μm, preferably 12 to 30 μm.
１５15 μm. Polyethylene layer (D) In the laminated film according to the present invention, the polyethylene layer (D) may be laminated on the surface of the aluminum layer (A), the linear low-density polyethylene layer (B), or the base material layer (C). However, as the polyethylene used to form the polyethylene layer (D), a high-pressure low-density polyethylene is mainly used. This high-pressure low-density polyethylene is a polyethylene produced by subjecting ethylene to high pressure in the presence of a radical polymerization catalyst. If necessary, a small amount of another vinyl monomer may be copolymerized.

The high-pressure low-density polyethylene used in the present invention has a density (ASTM D 1505) of usually 0.915 to 0.9.
35 g / cm ³ , preferably 0.915 to 0.925 g
/ Cm ³ . The high-pressure low-density polyethylene having a density in the above range is excellent in extrusion laminating processability. The density of the extruded strand obtained at the time of measuring the melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg was heat-treated at 100 ° C. for 1 hour, gradually cooled to room temperature over 1 hour, and then passed through a density gradient tube. Measure.

Further, the melt flow rate (MFR; ASTM D1238, 190 ° C., load
2.16 kg) is 1 to 70 g / 10 min, preferably 3 to 25 g
g / 10 minutes. High-pressure low-density polyethylene having a melt flow rate within the above range is excellent in extrusion lamination processability.

In the polyethylene layer (D), in addition to the high-pressure low-density polyethylene described above, a conventionally known olefin polymerization catalyst such as a Ziegler-based or metallocene-based olefin polymerization catalyst is used. Polyethylene can also be used. Linear low-density polyethylene is a copolymer of ethylene and one or more α-olefins, the α-olefin having 4 carbon atoms.
As described above, the number is preferably 5 to 8, and specific examples include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1-pentene.

The copolymerization ratio of ethylene and α-olefin in the linear low-density polyethylene is preferably 85 to 99.5 mol%, more preferably 90 to 99.0 mol%, of the constitutional unit derived from ethylene. %, And the proportion of the structural unit derived from an α-olefin having 4 or more carbon atoms is preferably 0.5 to 15 mol%, more preferably 1.0 to 10 mol%.

The density of linear low density polyethylene (ASTM D
1505) is usually 0.890 to 0.930 g / cm ³ , preferably 0.910 to 0.925 g / cm ³ . The linear low-density polyethylene having a density in the above range is excellent in extrusion lamination processability and interlayer adhesion with an anchor coat layer.

Further, the melt flow rate of this linear low density polyethylene (MFR; ASTM D1238, 190 ° C., load
2.16 kg) is usually 1 to 50 g / 10 min, preferably 5 to
It is 40 g / 10 min, more preferably 7 to 20 g / 10 min. A linear low-density polyethylene having a melt flow rate in the above range exhibits good flow characteristics (extrudability).

For the polyethylene layer (D), a resin composition obtained by blending the high-pressure low-density polyethylene (HP-LDPE) and the linear low-density polyethylene (L-LDPE) may be used. The mixing weight ratio [(HP-LDPE) / (L-LDP
E)] is usually from 70/30 to 40/60, preferably from 65/35 to 50/50.

Incidentally, medium-density polyethylene or high-density polyethylene can be used for the polyethylene layer (D). Further, a linear low-density polyethylene layer (B) prepared using the metallocene-based olefin polymerization catalyst.
In preparing a laminated film having a multilayer structure of three or more layers in which a polyethylene layer (D) is laminated on one side of the above, a polyethylene for forming the polyethylene layer (D) is prepared using a metallocene-based olefin polymerization catalyst. When the linear low-density polyethylene is used, a linear low-density polyethylene having a property different from that of the linear low-density polyethylene forming the linear low-density polyethylene layer (B) is used, or It is desirable to use a linear low-density polyethylene composition having different types of additives and the like and the amount of the additives.

If necessary, conventionally known slip agents, antiblocking agents, antistatic agents, weathering stabilizers, heat stabilizers, antifogging agents, pigments, dyes, fillers and the like may be added to the resin composition. Agents can be added within a range that does not impair the purpose of the present invention.

Such a resin composition is prepared by mixing or melt-kneading the high-pressure low-density polyethylene, the linear low-density polyethylene, and, if necessary, the various additives according to a conventionally known method. can get.

[0097] The resin composition thus prepared is
Melt flow rate (MFR; ASTM D1238, 190 ° C, load 2.16 kg) is usually 1 to 50 g / 10 min, preferably 3
２０20 g / 10 min, and the density (ASTM D 1505) is usually 0.900 to 0.930 g / cm ³ , preferably 0.910 to 0.925 g / cm ³ . Such a resin composition is excellent in extrusion laminating processability (high-speed spreadability, neck-in).

The thickness of the polyethylene layer (D) in the laminated film according to the present invention is usually 5 to 50 μm, preferably 10 to 30 μm. Laminated film The laminated film according to the present invention comprises at least the above-mentioned aluminum layer (A) and the linear low-density polyethylene layer (B), and if necessary, the above-mentioned base material layer (C) and further a polyethylene layer. (D) is a laminated film integrated and laminated.

In the present invention, a laminated film having a multilayer structure of three or more layers is added to the extruded laminate film composed of the linear low-density polyethylene layer (B) and the aluminum layer (A). Is arbitrary, and (1)
Base layer (C) / Aluminum layer (A) / Linear low density polyethylene layer (B) or (2) Base layer (C) / Polyethylene layer (D) / Aluminum layer (A) / Linear In addition to combining the above-mentioned various materials based on the basic structure of the low-density polyethylene layer (B), for example, (3) base layer (C) / polyethylene layer (D) / aluminum layer (A) / linear Like low-density polyethylene layer (B) / polyethylene layer (D), the purpose is to block the odor of high-temperature-processed linear low-density polyethylene layer (B) or to compensate for the reduced heat sealability. Or (4) base layer (C) / polyethylene layer (D) / base layer (C) / aluminum layer (A) / linear low-density polyethylene layer (B). And the like.

As a special example, (5) base material layer
(C) / linear low density polyethylene layer (B) / aluminum layer (A) / polyethylene layer (D).

As a specific example of the above configuration (1), the following configuration is exemplified. 1) Biaxially stretched nylon film layer / aluminum foil layer /
A structure comprising a metallocene linear low density polyethylene layer. 2) A structure comprising a polyethylene terephthalate film layer / aluminum foil layer / metallocene linear low density polyethylene layer. 3) A structure comprising a biaxially stretched polypropylene film layer / aluminum foil layer / metallocene linear low density polyethylene layer. 4) A structure composed of a biaxially stretched nylon film layer / aluminum-deposited polypropylene film layer / metallocene linear low-density polyethylene layer. 5) A structure composed of a biaxially stretched polypropylene film layer / aluminum-deposited polypropylene film layer / metallocene linear low-density polyethylene layer.

The above metallocene linear low density polyethylene refers to a linear low density polyethylene prepared using a metallocene olefin polymerization catalyst. A specific example of the configuration of the above (2) includes the following configuration. 1) A structure comprising a biaxially stretched nylon film layer / a high-pressure low-density polyethylene layer / aluminum foil layer / a metallocene linear low-density polyethylene layer. 2) A structure composed of a polyethylene terephthalate film layer / a high-pressure low-density polyethylene layer / aluminum foil layer / a metallocene linear low-density polyethylene layer. 3) A structure comprising a biaxially stretched polypropylene film layer / a high-pressure low-density polyethylene layer / aluminum foil layer / a metallocene linear low-density polyethylene layer. 4) A structure composed of a paper layer / high-pressure low-density polyethylene layer / aluminum foil layer / metallocene-based linear low-density polyethylene layer. 5) (High-pressure low-density polyethylene layer / paper layer) / high-pressure low-density polyethylene layer / aluminum foil layer / metallocene linear low-density polyethylene layer. 6) A structure comprising a biaxially stretched nylon film layer / a mixture layer of a Ziegler-based linear low-density polyethylene and a high-pressure low-density polyethylene / aluminum foil layer / a metallocene-based linear low-density polyethylene layer. 7) A structure consisting of a polyethylene terephthalate film layer / a mixture layer of a Ziegler-based linear low-density polyethylene and a high-pressure low-density polyethylene / aluminum foil layer / a metallocene-based linear low-density polyethylene layer. 8) A structure consisting of a biaxially oriented polypropylene film layer / a mixture layer of a Ziegler-based linear low-density polyethylene and a high-pressure low-density polyethylene / aluminum foil layer / a metallocene-based linear low-density polyethylene layer. 9) Composition comprising paper layer / mixed layer of Ziegler-based linear low-density polyethylene and high-pressure low-density polyethylene / aluminum foil layer / metallocene-based linear low-density polyethylene layer. 10) (high-pressure low-density polyethylene layer / paper layer) / mixture layer of Ziegler-based linear low-density polyethylene and high-pressure low-density polyethylene / aluminum foil layer / metallocene-based linear low-density polyethylene layer. 11) A structure consisting of a biaxially stretched nylon film layer / a high-pressure low-density polyethylene layer / aluminum-deposited polypropylene film layer / a metallocene linear low-density polyethylene layer. 12) A structure consisting of a biaxially stretched polypropylene film layer / a high-pressure low-density polyethylene layer / aluminum-deposited polypropylene film layer / a metallocene linear low-density polyethylene layer. 13) A structure consisting of a paper layer / high-pressure low-density polyethylene layer / aluminum-deposited polypropylene film layer / metallocene linear low-density polyethylene layer. 14) A structure consisting of a biaxially stretched nylon film layer / high-pressure low-density polyethylene layer / aluminum-deposited ethylene / vinyl alcohol copolymer film layer / metallocene linear low-density polyethylene layer.

The above-mentioned Ziegler-based linear low-density polyethylene refers to a linear low-density polyethylene prepared using a Ziegler-based olefin polymerization catalyst. A specific example of the configuration of the above (3) includes the following configuration. 1) A structure consisting of a biaxially stretched nylon film layer / high-pressure low-density polyethylene layer / aluminum foil layer / metallocene-based linear low-density polyethylene layer / high-pressure low-density polyethylene layer. 2) A structure comprising a biaxially stretched nylon film layer / a high-pressure low-density polyethylene layer / aluminum foil layer / a metallocene-based linear low-density polyethylene layer / a metallocene-based linear low-density polyethylene layer.

The following is a specific example of the configuration (4). 1) A structure composed of a biaxially stretched nylon film layer / a high-pressure low-density polyethylene layer / a biaxially stretched nylon film layer / aluminum foil layer / a metallocene linear low-density polyethylene layer. 2) A structure composed of a polyethylene terephthalate film layer / a high-pressure low-density polyethylene layer / a polyethylene terephthalate film layer / aluminum foil layer / a metallocene linear low-density polyethylene layer. 3) Biaxially oriented polypropylene film layer / High pressure low density polyethylene layer / Biaxially oriented polypropylene film layer /
A structure comprising an aluminum foil layer / a metallocene linear low density polyethylene layer. 4) A structure composed of a paper layer / high-pressure low-density polyethylene layer / paper layer / aluminum foil layer / metallocene linear low-density polyethylene layer. 5) (high pressure method low density polyethylene layer / paper layer) / biaxially oriented polypropylene film layer / high pressure method low density polyethylene layer / biaxially oriented nylon film layer / aluminum foil layer /
A structure comprising a metallocene linear low density polyethylene layer.

The laminated film according to the present invention comprises a two-layer film comprising an aluminum layer (A) and a linear low-density polyethylene layer (B), and a linear low-density polyethylene layer (B ), The oxygen concentration of the linear low-density polyethylene alone (excluding the oxygen concentration derived from additives and the like) on the surface of the linear low-density polyethylene layer (B) is 1.0 to 1. It is 4 atomic%, preferably 1.2 to 1.3 atomic%. Oxygen atoms contained in the linear low-density polyethylene on the surface of the linear low-density polyethylene layer (B) are derived from the outside like oxygen in the atmosphere, and on the aluminum layer (A), It is considered that when the linear low-density polyethylene layer (B) is extrusion-laminated, it is taken in from oxygen in the atmosphere or the like. When the oxygen concentration is within the above range, a high heat sealing strength and a low sealing start temperature can be achieved. This oxygen concentration can be calculated by measuring the X-ray photoelectron spectrum of the surface of the linear low-density polyethylene layer (B) and determining the atomic composition from the peak intensity. When the linear low-density polyethylene layer (B) contains an additive and the like in addition to the linear low-density polyethylene, the oxygen concentration can be obtained by excluding the additive and the like.

Method for Producing a Laminated Film The laminated film according to the present invention comprising the above-described aluminum layer (A) and the linear low-density polyethylene layer (B) is obtained by employing a conventionally known extrusion lamination method. It can be manufactured by adjusting the laminating conditions so that the oxygen concentration on the surface of the linear low-density polyethylene layer (B) is in the range of 1.0 to 1.4 atomic%. For example, the resin temperature of the linear low-density polyethylene prepared by using the metallocene-based olefin polymerization catalyst described above is set to 31.
It can be carried out by adjusting the laminating atmosphere and the laminating speed under the conditions of 0 to 320 ° C, preferably 312 to 318 ° C.

The laminated film according to the present invention, in which the linear low-density polyethylene layer (B), the aluminum layer (A), and the base layer (C) are laminated in this order, comprises, for example, a base layer (C) ) And the aluminum layer (A) are dry-laminated, and the linear low-density polyethylene layer (B) is extrusion-laminated on the aluminum layer (A) under the above conditions.

Further, a linear low-density polyethylene layer (B), an aluminum layer (A), and a polyethylene layer (D)
The laminated film according to the present invention, in which the base layer (C) is laminated in this order, comprises a polyethylene layer (D) and an aluminum layer (A) on the base layer (C) by, for example, a tandem luminescence method. Are sequentially laminated, and then a linear low-density polyethylene layer (B) is formed on the aluminum layer (A) by extrusion lamination under the above conditions.

The laminated film according to the present invention having a layer structure different from the layer structure of the above-mentioned laminated film can be produced by the above-mentioned laminating method or the like.

[0110]

According to the present invention, an aluminum layer such as an aluminum foil or an aluminum vapor-deposited film, and a linear low-density polyethylene layer prepared using a metallocene-based olefin polymerization catalyst are used. And a laminated film having an excellent balance between the heat sealing properties of the linear low-density polyethylene layers and the linear low-density polyethylene layers can be provided at low cost. Furthermore, a layer is added to this laminated film, and at least a linear low-density polyethylene layer, an aluminum layer composed of an aluminum foil or an aluminum vapor-deposited film, and a laminated film in which the base material layer is formed in this order at a low cost. Can be provided.

The laminated film according to the present invention is suitable, for example, as a packaging material for dried food. Specific examples of dried foods include snacks such as potato chips, biscuits,
Examples include confectioneries such as rice crackers and chocolates, powdered seasonings such as powdered soups and broths, and dried foods such as shaved knots and smoked foods.

[0112]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

For the laminated films obtained in Examples and Comparative Examples, tests for heat sealability, adhesive strength to aluminum, and surface oxygen concentration were carried out according to the following methods.

<Test Method> (1) Heat Sealability A heat seal strength test was performed under the following conditions. Also,
In this heat seal strength measurement, the heat seal start temperature was measured, and the low temperature heat sealability was evaluated based on the heat seal start temperature. Here, the heat sealing start temperature refers to a temperature immediately after the peeled surface changes from interfacial peeling to cohesive peeling in heat seal strength measurement. Heat sealing conditions] · sided heating bar sealer employed, heat seal pressure: 2 kg / cm ² Heat sealing time: 0.5 sec Seal bar width: 10 mm, specimen width: 15 mm, peel angle: 180 degrees - Peeling speed: 300 mm / min (2) Adhesive strength to aluminum Paper layer / High-pressure method low-density polyethylene layer (20 μm thickness) / Aluminum foil layer (9 μm thickness) / Sealant resin layer (30 μm
Thickness) / urethane-based anchor coating agent / polyethylene terephthalate layer (12 μm thick) was prepared into an extruded laminate film, and the interlayer adhesion strength of the aluminum layer / the resin layer for the sealant was measured under the following conditions. [Measurement conditions of interlayer adhesion strength]-Peeling angle: 180 degrees-Peeling speed: 300 mm / min-Specimen width: 15 mm (3) Surface oxygen concentration X-rays on the surface of the metallocene linear low density polyethylene layer of the extruded laminate film The photoelectron spectrum was measured, the atomic composition was determined from the peak intensity, and the surface oxygen concentration was calculated.

Next, the definition and measurement method of the physical properties of the linear low density polyethylene (ethylene / α-olefin copolymer) used in the present invention will be described. (1) Density A strand obtained at the time of measuring a melt flow rate at a load of 2.16 kg at 190 ° C. is heat-treated at 100 ° C. for 1 hour, gradually cooled to room temperature over 1 hour, and measured with a density gradient tube. (2) Composition of copolymer Determined by ¹³ C-NMR. That is, ¹³ C of a sample in which about 200 mg of a copolymer powder was uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube.
Determined by measuring the NMRR spectrum under measurement conditions of a measurement temperature of 120 ° C., a measurement frequency of 25.05 MHz, a spectrum width of 1500 Hz, a pulse repetition time of 4.2 sec, and a pulse width of 6 μsec. (3) Melt flow rate (MFR) Melt flow rate is ASTM D1238-65T
Is measured at 190 ° C. under a load of 2.16 kg. (4) Maximum peak temperature (Tm) by differential scanning calorimeter (DSC) The measurement was performed using a DSC-7 type device manufactured by Perkin Elmer. Temperature at maximum peak position in endothermic curve (Tm)
Is to pack about 5 mg of the sample into an aluminum pan at 10 ° C / min.
After the temperature was raised to 0 ° C and kept at 200 ° C for 5 minutes,
It is determined from an endothermic curve when the temperature is lowered to room temperature at a rate of 10 ° C./minute and then at a rate of 10 ° C./minute. (5) n-decane-soluble component (W) The measurement of the n-decane-soluble component of the copolymer is performed by measuring about 3 g of the copolymer.
Add to 450 ml of n-decane, dissolve at 145 ° C, cool to 23 ° C, remove the n-decane insoluble part by filtration, and remove from the filtrate.
This is performed by recovering the n-decane soluble part.

W = (weight of n-decane-soluble portion) / (weight of n-decane-insoluble portion and soluble portion) × 100%.
A smaller decane soluble content means a narrower composition distribution. (6) Melt tension (MT) It is determined by measuring the stress when the melted polymer is stretched at a constant speed. In other words, granulated pellets of the copolymer were used as measurement samples, and were manufactured by Toyo Seiki Seisaku-sho, Ltd.
Using an MT measuring machine, resin temperature 190 ° C, extrusion speed 1
The operation is performed under the conditions of 5 mm / min, a winding speed of 10 to 20 m / min, a nozzle diameter of 2.09 mmφ, and a nozzle length of 8 mm. (7) Fluidity index (FI) The fluidity index was determined by extruding the resin from the capillary while changing the shear rate, and measuring the stress at that time. That is, using the same sample as in the MT measurement, using a capillary flow characteristic tester manufactured by Toyo Seiki Seisaku-sho, Ltd., at a resin temperature of 190 ° C. and a shear stress range of 5 × 10 ⁴
It is measured at about 3 × 10 ⁶ dyne / cm ² .

The MFR of the resin to be measured (g / 10 minutes)
The measurement is performed by changing the diameter of the nozzle (capillary) as follows. 0.5 mm when MFR> 20 1.0 mm when 20 ≧ MFR> 3 2.0 mm when 3 ≧ MFR> 0.8 3.0 mm when 0.8 ≧ MFR

[0118]

Example 1 Biaxially stretched nylon film having a thickness of 15 μm [trade name: Emblem ONM, manufactured by Unitika Ltd.]
A urethane-based anchor coating agent was applied to one side (abbreviated as “ONy”) to evaporate the solvent. Thereafter, 50 parts by weight of a linear low-density polyethylene (abbreviated as “T-LLDPE”) and a high-pressure low-density polyethylene (abbreviated as “HPLDPE”) each prepared using a Ziegler-based olefin polymerization catalyst were blended in an amount of 50 parts by weight. The mixed resin was extrusion-laminated to a thickness of 25 μm, and a linear low-density polyethylene (abbreviated as “M-LLDPE”) prepared using a metallocene-based olefin polymerization catalyst (density (ASTM D 1505): 0.900 g / cm ³ , MFR (AS
TM D 1238, 190 ° C, load 2.16 kg): 7.3 g / 10 minutes,
α-Olefin: 1-octene] is extrusion-laminated to a thickness of 30 μm, and the ONy layer (15 μm thickness) / T-LLDP
Mixed resin layer of E and HPLDPE (25 μm thickness) / ML
An extruded laminate film having an LDPE layer (30 μ thickness) was produced.

The extruded laminate was subjected to a 65 mmφ extruder and a laminator having a 500 mm wide T die.
The take-up speed was 80 m / min, the resin temperature under the die was 315 ° C., and the air gap was 130 mm.

The heat sealing strength between the M-LLDPE layers of the extruded laminate film obtained as described above,
The low-temperature heat sealability and the surface oxygen concentration of the M-LLDPE layer were measured or evaluated according to the above method.

The results are shown in Table 1. In addition, thickness 12
μm polyethylene terephthalate film (“PE
T ") [trade name Lumirror, manufactured by Toray Industries, Inc.]
A urethane anchor coating agent (abbreviated as “AC agent”) was applied to evaporate the solvent. Thereafter, a laminate film having a structure of paper layer / HPLDPE layer (20 μm thickness) / aluminum layer (9 μm thickness) was used as a sandwich film,
-Sandwich-laminate LLDPE to a thickness of 30 μm, paper layer / HPLDPE layer (20 μm thickness) / aluminum layer (9 μm layer) / M-LLDPE layer (30 μm thickness) / AC
An extruded laminate film having a composition of agent / PET (12 μm thick) was produced.

The above sandwich laminate is 65 mm
Using a φ extruder and a laminator having a 500 mm wide T die, a take-up speed of 80 m / min and a resin temperature of 315 below the die
C. and an air gap of 130 mm.

The interlayer adhesion strength of aluminum / M-LLDPE of the laminate film obtained as described above was measured according to the above method. Table 1 shows the results.

[0124]

Embodiment 2 According to the embodiment 1, the air gap is set to 200.
mm, ONy layer (15 μm thickness) / mixed resin layer of T-LLDPE and HPLDPE (25 μm thickness) / M-LLD
Extruded laminated film of PE (30 μm thickness) and paper layer / HPLDPE layer (20 μm thickness) / aluminum layer (9 μm thickness) / M-LLDPE layer (30 μm thickness) / AC agent / PET layer (12 μm thickness) Of the M-LLDPE layers, the low-temperature heat sealability, the surface oxygen concentration of the M-LLDPE layer, and the interlayer adhesion strength of aluminum / M-LLDPE were not measured according to the above method. evaluated.

Table 1 shows the results.

[0126]

Example 3 According to Example 1, the coating thickness of the M-LLDPE layer was set to 20 μm, and the ONy layer (15 μm thickness) / T−
Mixed resin layer of LLDPE and HPLDPE (25μm thickness)
/ M-LLDPE layer (20 μm thickness) extruded laminate film, and paper layer / HPLDPE layer (20 μm thickness)
/ Aluminum layer (9 μm thick) / M-LLDPE (20 μm
Thickness) / AC agent / PET layer (12 μm) to produce an extruded laminate film, heat seal strength between M-LLDPE layers, low temperature heat sealability, surface oxygen concentration of M-LLDPE layer, and aluminum / M -The interlayer adhesive strength of LLDPE was measured according to the above method.

Table 1 shows the results.

[0128]

Comparative Example 1 According to Example 1, the temperature of the resin for laminating the M-LLDPE layer was set to 305 ° C., and the ONy layer (15
Extruded laminated film composed of resin layer of T-LLDPE and HPLDPE (25 μm thickness) / M-LLDPE layer (30 μm), and paper layer / HPLDPE layer (20 μm thickness) / aluminum layer (9 μm thickness) / M-LLD
An extruded laminate film having a structure of PE layer (30 μm thickness) / AC agent / PET layer (12 μm) was prepared and M-LLDPE
Heat seal strength between layers, low temperature heat sealability, M-
Surface oxygen concentration of LLDPE layer, and aluminum / M
-The interlayer adhesion strength of LLDPE was measured or evaluated according to the above method.

Table 1 shows the results.

[0130]

Comparative Example 2 According to Example 1, the temperature of the resin for laminating the M-LLDPE layer was set to 325 ° C., and the ONy layer (15
μm) / extruded laminate film having a composition of a mixed resin layer of T-LLDPE and HPLDPE (25 μm) / M-LLDPE layer (30 μm), and a paper layer / HPLDPE layer (20 μm).
μm thickness) / Aluminum layer (9 μm thickness) / M-LLDPE
Layer (30 μm thick) / AC agent / PET layer (12 μm) to produce an extruded laminate film, heat-sealing strength between M-LLDPE layers, low-temperature heat-sealing property, M-LL
Surface oxygen concentration of DPE layer, and aluminum / ML
The interlayer adhesive strength of LDPE was measured or evaluated according to the above method.

Table 1 shows the results.

[0132]

Comparative Example 3 According to Example 1, the M-LLDPE layer was changed to H
Instead of the PLDPE layer, the laminating resin temperature is set to 32
At 0 ° C., ONy layer (15 μm thickness) / mixed resin layer of T-LLDPE and HPLDPE (25 μm thickness) / HPLDP
Extruded laminated film having E layer (30 μm thickness), paper layer / HPLDPE layer (20 μm) / aluminum layer
(9 μm) / HPLDPE layer (30 μm) / AC agent / PET
An extruded laminate film having a layer structure (12 μm) was prepared, and the heat seal strength between the HPLDPE layers, the low-temperature heat sealability, the surface oxygen concentration of the HPLDPE layer, and the interlayer adhesion strength of aluminum / HPLDPE were measured or evaluated according to the above method. did.

The results are shown in Table 1.

[0134]

Comparative Example 4 An M-LLDPE layer was formed from an ionomer resin [trade name: Himilan ^™ H1652,
Made by DuPont-Mitsui Polychemicals Co., Ltd.], the laminating resin temperature was set to 290 ° C., and the ONy layer (15 μm
Thickness) / Extruded laminated film composed of mixed resin layer of T-LLDPE and HPLDPE (25 μm) / ionomer resin layer (30 μm), and paper layer / HPLDPE layer (20 μm thickness) / aluminum layer (9 μm) / ionomer resin layer An extruded laminate film having a structure of (30 μm thickness) / AC agent / PET layer (12 μm) was prepared, and the heat seal strength between the ionomer resin layers, the low-temperature heat sealability, and the interlayer adhesion strength between the aluminum / ionomer resin were determined by the above-described method. Was performed according to

Table 1 shows the results.

[0136]

Comparative Example 5 According to Example 1, the M-LLDPE layer was made of an ethylene-methacrylic acid copolymer (abbreviated as “EMAA”) [trade name: Nucrel ^™ N0908C, manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.] Laminating resin temperature is 280 ° C, ONy layer (15μm thick) / T-
Mixed resin layer of LLDPE and HPLDPE (25μm thickness)
Extruded laminated film having a composition of / EMAA (thickness of 30 μm) and extrusion of a paper layer / HPLDPE layer (thickness of 20 μm) / aluminum layer (thickness of 9 μm) / EMAA layer (thickness of 30 μm) / AC agent / PET layer (12 μm) A laminate film was prepared, and the heat sealing strength between the EMAA layers, the low-temperature heat sealing property, and the aluminum / EMAA interlayer adhesion strength were measured or evaluated.

Table 1 shows the results.

[0138]

[Table 1]

The M-L of the extruded laminate film of Example 1 manufactured by setting the resin temperature of M-LLDPE to 315 ° C.
The heat sealing property between the LDPE layers is lower than that between the ionomer resin layers of the extruded laminated film of Comparative Example 4 having the same configuration manufactured by setting the resin temperature of the ionomer resin to 290 ° C. Although the same, the heat sealing strength (110 ° C.) is 1.5 times as strong.

Similarly, the heat sealing property between the M-LLDPE layers in the extruded laminate film of Example 1 was
Compared to the heat sealability of the EMAA layers of the extruded laminate film of Comparative Example 5 in which EMAA was produced at a resin temperature of 280 ° C., the low temperature heat sealability was 5 ° C. lower and the heat seal strength (120 ° C.) was 1.3 times. Met.

In these examples, although the adhesive strength to the aluminum layer is reduced, the strength is kept practically sufficient, while the adhesiveness between the M-LLDPE layers is remarkably improved, and The overall rating is excellent.

[0142]

Example 4 Ethylene / 1-hexene copolymer (linear low-
After the suspension concentrate for 10 hours dried silica 7.9kg in preparation Preparation of the catalyst component] 250 ° C. density polyethylene) 121 liters of toluene, and cooled to 0 ° C.. Then, a toluene solution of methylaluminoxane (Al = 1.47 mol / L)
41 liters were added dropwise over one hour. At this time, the temperature in the system was kept at 0 ° C. Subsequently, silica and methylaluminoxane were reacted at 0 ° C. for 30 minutes, then heated to 95 ° C. over 1.5 hours, and reacted at that temperature for 4 hours.
Thereafter, the temperature was lowered to 60 ° C., and the supernatant was removed by a decantation method. The solid component thus obtained was washed twice with toluene and then resuspended in 125 liters of toluene. Into this system, a toluene solution of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride (Z
r = 28.4 mmol / l) 20 liters to 30
The mixture was added dropwise at 30 ° C. over 30 minutes, and further reacted at 30 ° C. for 2 hours. Thereafter, the supernatant was removed and washed twice with hexane to obtain a solid catalyst containing 4.6 mg of zirconium per gram.

[Preparation of Prepolymerized Catalyst] To 160 liters of hexane containing 16 mol of triisobutylaluminum, 4.3 kg of the solid catalyst obtained above was added.
Preliminary polymerization of ethylene was performed at 35 ° C. for 3.5 hours to obtain a prepolymerized catalyst in which 3 g of polyethylene was prepolymerized per 1 g of the solid catalyst. 13 of this ethylene polymer
The intrinsic viscosity [η] measured in decalin at 5 ° C. is 1.27
dl / g.

[Polymerization] Ethylene and 1-hexene were copolymerized at a total pressure of 20 kg / cm ² -G and a polymerization temperature of 80 ° C. using a continuous fluidized bed gas phase polymerization apparatus. The prepolymerized catalyst prepared above was converted to 0.05 mmol in terms of zirconium atoms.
l / hr, 10 mmol of triisobutylaluminum
/ Hr, and ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied to maintain a constant gas composition during the polymerization.

The yield of the obtained ethylene / 1-hexene copolymer (M-LLDPE-2) was 5.2 kg / hr, the density was 0.900 g / cm ³ , and the MFR was 5.6 g / hr. It was 10 minutes, the maximum peak of the melting point in DSC was 102.8 ° C, and the n-decane-soluble portion at 23 ° C was 0.82% by weight.

[0146]

[Table 2]

The ethylene / 1-hexene copolymer (M-
LLDPE-2) and according to Example 1, ONy layer (15 μm thickness) / mixed resin layer of T-LLDPE and HPLDPE (25 μm thickness) / M-LLDPE-2 layer (30 μm thickness)
Extruded laminate film having the following structure, and paper layer / HPL
DPE layer (20 μm thickness) / Aluminum layer (9 μm thickness) / M
-LLDPE (30 μm thickness) / AC agent / PET layer (12 μm
m) to prepare an extruded laminate film having the structure
The heat seal strength between the LDPE-2 layers, the low-temperature heat sealability, the surface oxygen concentration of the M-LLDPE-2 layer, and the interlayer adhesion strength of aluminum / M-LLDPE-2 were measured according to the above methods.

Table 3 shows the results.

[0149]

Example 5 The above ethylene / 1-hexene copolymer (M-
M-LLD using LLDPE-2) and according to Example 1.
PE-2 layer (30 μm thickness) / Aluminum layer (9 μm thickness) /
An extruded laminate film having an ONy layer (15 μm thickness) was prepared, and heat seal strength between M-LLDPE-2 layers, low-temperature heat sealability, surface oxygen concentration of M-LLDPE-2 layer, and aluminum / M− The interlayer adhesion strength of LLDPE-2 was measured according to the method described above.

Table 3 shows the results.

[0151]

Example 6 The above ethylene / 1-hexene copolymer (M-
M-LLD using LLDPE-2) and according to Example 1.
PE-2 layer (30 μm thickness) / Aluminum layer (9 μm thickness) /
An extruded laminate film having a constitution of HPLDPE layer (20 μm thickness) / ONy layer (15 μm thickness) was prepared and M-LL
The heat sealing strength between the DPE-2 layers, the low-temperature heat sealing property, the surface oxygen concentration of the M-LLDPE-2 layer, and the interlayer adhesion strength of aluminum / M-LLDPE-2 were measured according to the above-mentioned methods.

Table 3 shows the results.

[0153]

Comparative Example 6 The same procedure as in Example 6 was repeated except that the ethylene / 1-hexene copolymer (M-LLDPE-2) was replaced with the HP
Using LDPE, according to Example 6, HPLDPE layer (30 μm thickness) / aluminum layer (9 μm thickness) / HPLD
An extruded laminate film having a structure of PE layer (20 μm thickness) / ONy layer (15 μm thickness) was prepared, and the heat seal strength between HPLDPE layers, low-temperature heat sealability, and interlayer adhesion strength between aluminum / HPLDPE were determined according to the above-described method. It was measured.

Table 3 shows the results.

[0155]

Example 7 The above ethylene / 1-hexene copolymer (M-
M-LLD using LLDPE-2) and according to Example 1.
PE-2 layer (30 μm thickness) / Aluminum layer (9 μm thickness) /
PET (12 μm) / HPLDPE layer (20 μm) / ONy
Extruded laminate film having a layer (15 μm thickness) configuration was prepared, and the heat seal strength between M-LLDPE-2 layers was determined.
The low-temperature heat sealability, the surface oxygen concentration of the M-LLDPE-2 layer, and the interlayer adhesion strength of aluminum / M-LLDPE-2 were measured according to the methods described above.

The results are shown in Table 3.

[0157]

[Table 3]

Claims (10)

[Claims] 1. A laminated film comprising at least an aluminum layer (A) and a linear low-density polyethylene layer (B) extrusion-laminated on one side of the aluminum layer (A) to form the layer (B). The linear low-density polyethylene is prepared by using a metallocene-based olefin polymerization catalyst, and (i) the density (d; ASTM D 1505) is 0.895-0.
Was 930g / cm ^3, (ii) a melt flow rate (MFR; ASTM D 1238,190 ℃, load 2.16 kg) of 0.1
The laminated film has an oxygen concentration of 1.0 to 1.4 on the surface of the linear low-density polyethylene layer (B).
A laminated film characterized by atomic%. 2. The linear low-density polyethylene constituting the linear low-density polyethylene layer (B) comprises (iii) 190
The melt tension at ℃ (MT (g)) and the melt flow rate (MFR (g / 10 minutes)) satisfy the relationship of MT> 2.0 × MFR- ^0.84 , (iv) of the molten polymer 190 ° C
The fluidity index (F) defined by the shear rate when the shear stress reaches 2.4 × 10 ⁶ dyne / cm ² at
I (1 / sec)) and the melt flow rate (MFR (g /
10 min)), satisfying the relationship of FI> 75 × MFR, (v) n-decane soluble matter (W (% by weight)) at 23 ° C. and density (d (g / c)
m ³ )), when MFR ≦ 10 g / 10 min: W <80 × exp (−100 (d−0.88)) + 0.1 When MFR> 10 g / 10 min: W <80 × (MFR −9) ^0.26 × exp (−100 (d−
0.88)) + 0.1, and (vi) the temperature (T) at the maximum peak position in the endothermic curve measured by the differential scanning calorimeter.
m (° C.)) and density (d (g / cm ³ )) are ethylene / α-olefin copolymers satisfying the relationship expressed by Tm <400d-250. The laminated film according to the above. (3) The melt tension (MT (g)) at 190 ° C. and the melt flow rate (MFR (g / g)
10)) further satisfies the relationship ^represented by MT> 2.2 × MFR- ^0.84 . 4. A base material layer (C) is further formed on the aluminum layer (A) on one side of the aluminum layer (A) opposite to the linear low-density polyethylene layer (B). The laminated film according to claim 1, wherein the laminated film is formed. 5. A polyethylene layer (D) and a base material on the aluminum layer (A) opposite to the linear low-density polyethylene layer (B) formed on one side of the aluminum layer (A). The laminated film according to claim 1, wherein the layers (C) are formed in this order. 6. A first polyethylene layer (D) on the aluminum layer (A) opposite to the linear low-density polyethylene layer (B) formed on one side of the aluminum layer (A). And a base layer (C) is formed in this order, and a second polyethylene layer (D) is formed on the linear low-density polyethylene layer (B). 2. The laminated film according to 1. 7. A first base material layer (C) on the aluminum layer (A) opposite to the linear low-density polyethylene layer (B) formed on one side of the aluminum layer (A). 2.) The laminated film according to claim 1, wherein the polyethylene film (D) and the second base material layer (C) are formed in this order. 8. The laminated film according to claim 1, wherein said aluminum layer (A) is an aluminum foil or an aluminum vapor-deposited film. 9. The laminated film according to claim 4, wherein said base layer (C) is made of paper, polyamide film, polyester film or polypropylene film. 10. The polyethylene layer (D) is made of high-pressure low-density polyethylene, linear low-density polyethylene, or a mixture thereof.
The laminated film according to any one of the above.