JPH11138710A - Package multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an inexpensive package multilayer film employed in package such as the pre-pack of foods and the like that is a multilayer film consisting of a polyolefin polymer, has an appropriate elongation elasticity and adhesiveness, and balanced abilities such as an excellent transparency, a cutting property, a heat sealing property, clouding resistivity, an anti-perforation property, finger- pressure restorativeness or the like. SOLUTION: The film is formed such that an inner layer consisting of an inner layer composition containing a high-melting point component and a flexible component is interposed between outer layers consisting of an outer layer resin composition containing a 99.5-90 wt.% ethylene.vinyl acetate copolymer being a copolymer of ethylene and vinyl acetate and having a content of vinyl acetate of 10-30 wt.% and a melt-flow rate of 0.5-30 g/10 min., and anti-clouding agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin-based multilayer film for use in various packaging applications such as prepacking and heat-sealing packaging in supermarkets and the like, and more particularly to transparency and heat-sealing properties. The present invention relates to a multilayer film for packaging which is excellent not only in performance but also in cutability, perforation resistance and acupressure recovery.

[0002]

2. Description of the Related Art Conventionally, plastic films have been used in supermarkets and the like as business-use packaging films for prepacking foods such as vegetables. This pre-pack film is a film for covering and packaging foods that are subdivided and stored in plastic trays or the like, or foods that are naked, while being transparent and having appropriate stretch elasticity and adhesiveness. It can be cut easily, does not fog from the inside of the film when wrapped, does not easily open holes due to the heat of the seal bar at the time of heat sealing, perforation resistance, finger pressure restoring property that leaves no trace of finger pressing, heat Performance such as excellent sealing performance is required. Conventionally, a film made of a polyvinyl chloride polymer or an ethylene / vinyl acetate copolymer has been used as such a packaging film. Among them, polyvinyl chloride-based polymers have excellent performance, but materials that do not contain chlorine have been demanded due to recent environmental problems.

As a packaging film for improving such a point, Japanese Patent Application Laid-Open No. 4-246536 discloses a linear low-density ethylene / α-olefin copolymer and a low-density polyethylene and / or ethylene / vinyl acetate copolymer. A multilayer film in which an intermediate layer made of a butene-based resin is laminated between outer layers made of a stretch film is disclosed.
However, such a multilayer film is excellent in transparency, elongation elasticity, cutability, etc., but has a problem that adhesiveness and heat sealability are not always sufficient.In order to improve these, the density of the outer layer is reduced. When the temperature is lowered, the heat sealing property is certainly improved, but on the other hand, holes are easily formed in the film at the time of high temperature sealing. Therefore, if polyethylene or polypropylene having high heat resistance is used for the inner layer, since these resins usually have high crystallinity, there is a problem that traces of pressing with a finger are likely to remain.

Japanese Patent Application Laid-Open No. 8-66992 discloses a packaging film made of a chlorine-free material having a density of 0.900.
~0.915g / cm ^3, melting point 90 ° C. or more first ethylene · alpha-olefin copolymer and density 0.900g
/ Cm ³ , the second ethylene α- having a melting point of less than 80 ° C.
A polyolefin stretch film in which an inner layer made of a first and second ethylene / α-olefin copolymer is laminated between outer layers made of a composition containing an olefin copolymer is described.

[0005] For this film, for example, by using a composition containing a high-melting-point ethylene / α-olefin copolymer and a low-melting-point ethylene / α-olefin copolymer for the inner layer, a film having a low permanent set is obtained. However, when ethylene and α-olefins are combined with each other, they become compatible with each other, resulting in intermediate properties between them. However, there is a problem that both the acupressure restoration properties expected from the above-mentioned method become incomplete.

[0006]

SUMMARY OF THE INVENTION The present inventor has studied the use of a polyolefin resin as a material for a multilayer film for packaging, and has physical properties comparable to those of a polyvinyl chloride film. As a result of examining a multilayer film that can withstand heat, by laminating layers composed of a specific olefin-based resin composition, transparency, cutability, perforation resistance and finger pressure recovery are excellent, and balanced performance is obtained. The present inventors have found that a multilayer film for packaging can be obtained, and have reached the present invention. An object of the present invention is a multilayer film for packaging comprising a polyolefin-based polymer, which has a suitable elongation elasticity and adhesiveness, and has transparency, cutability, heat sealability, anti-fog properties, anti-perforation properties and An object of the present invention is to provide an inexpensive multi-layer packaging film having balanced performances such as excellent acupressure restoration properties.

[0007]

The present invention relates to the following multilayer film for packaging. (1) A multilayer film for packaging, wherein an inner layer made of the following inner layer resin composition is laminated between outer layers made of the following outer layer resin composition. Outer layer resin composition: (A) a copolymer of ethylene and vinyl acetate, wherein the content of vinyl acetate is 10 to 30% by weight, 190 ° C,
99.5 to 90% by weight of an ethylene / vinyl acetate copolymer having a melt flow rate (MFR) at a load of 16 kg of 0.5 to 30 g / 10 min, and (B) 0.5 to 10% by weight of an antifogging agent. Inner layer resin composition: [I] (C) an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and a melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg Is 0.1 to 10 g / 10
An ethylene polymer having a density of 0.930 to 0.980 g / cm ³ and / or (D) 230 ° C., 2.16
The melt flow rate (MFR) under a kg load is 0.
1 to 100 g / 10 min, density 0.880 to 0.920
g / cm ³ of a propylene-based polymer and [II] (E) a polymer block (e-1) of styrene or a derivative thereof,
A polymer block of an α-olefin having 2 to 20 carbon atoms (e
-2), and a copolymer block of styrene or a derivative thereof and an α-olefin having 2 to 20 carbon atoms (e-
3) at least one polymer block selected from the group consisting of: and an isoprene polymer block or an isoprene / butadiene copolymer block, wherein the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion is A polymer or copolymer block (e-4) having 25% by weight or more, and a polymer block (e) having butadiene polymer blocks having 1,2 and 3,4 vinyl bond amounts of 25% by weight or more -5) an optionally hydrogenated block copolymer comprising at least one polymer block selected from the group consisting of: (F) a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms Having a melt flow rate (MFR) at 190 ° C. and a load of 2.16 kg of 0.1 to 10 g / 10 min, and a density of 0.850 to 0.895. Ethylene · alpha-olefin copolymer ^{/ cm 3, (G) (} g-1) the following formula [1] or [2]

Embedded image [In the formula [1], n is 0 or 1, m is 0 or a positive integer, q is 0 or 1, and R ^{1 to} R
¹⁸ and R ^a and R ^b each independently represent an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group, and R ¹⁵ and R ¹⁶ are bonded to each other to form a monocyclic or polycyclic And the monocyclic or polycyclic ring may have a double bond, and R ¹⁵ and R ¹⁶ or R ¹⁷ and R ¹⁸ form an alkylidene group. You may. Here, when q is 0, the respective bonds are combined to form a 5-membered ring. ]

Embedded image [In the formula [2], m is 0 or a positive integer, and h
Is 0 or a positive integer; j and k are 0, 1 or 2; R ^{7 to} R ¹⁵ and R ^{17 to} R ¹⁸ each independently represent a group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group; Represents an atom or a group selected from R ^{19 to} R ²⁷
Each independently represents an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group and an alkoxy group. An α-olefin / cyclic olefin random copolymer comprising a copolymer of a cyclic olefin represented by the formula: and ethylene and / or an α-olefin having 3 to 20 carbon atoms, (g-2) the formula [1] Or a ring-opened (co) polymer of a cyclic olefin represented by [2] or a hydrogenated product thereof, and (g-3) a random copolymer of the α-olefin / cycloolefin random copolymer (g-1) or the cyclic olefin. Ring-opening (co) polymer or its hydrogenated product (g
-2) at least one cyclic olefin resin selected from the group consisting of the graft-modified products, having a glass transition temperature of 30 ° C or lower and a melt flow rate (MFR) of 0.1 to 10 g / 10 min. Cyclic olefin resin,
(H) A copolymer of an aromatic monomer and ethylene and / or another α-olefin, having a glass transition temperature of 30 ° C. or lower and a melt flow rate (MFR) of 0.1
(J) a copolymer of propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms, wherein the composition of each component is propylene 1
0-85 mol%, 1-butene 3-60 mol% and C5-C12 α-olefin 10-85 mol%,
An olefin copolymer having an intrinsic viscosity [η] of 0.5 to 6 dl / g measured at 135 ° C. in decahydronaphthalene, particularly preferably having a crystallinity of 20% or less as measured by X-ray diffraction; The dynamic elastic modulus (E ') measured at 25 ° C. is 5 × 10 ^{7 to} 5 × 10 ⁹ dyn / cm ² ,
An olefin copolymer having a loss coefficient (tan δ) at 25 ° C of 0.4 or more, a boiling n-heptane-insoluble content of 5% by weight or less, and an acetone-soluble content at 25 ° C of 3% by weight or less, and (K) The melt flow rate (MFR) at 190 ° C. and a load of 2.16 kg is 0.1 to 5 g / 1.
0 minutes, at least one resin selected from the group of the components (E) to (K) consisting of a butene-based polymer having a density of 0.890 to 0.915 g / cm ³ [provided that the components (C) and (F) The components are not used together. And a resin composition comprising: (2) When the mixing ratio of the inner layer resin composition is (C) and / or
Or (D) 5 to 95% by weight of component, (E), (F),
The multi-layer film for packaging according to the above (1), wherein it is 95 to 5% by weight of at least one component selected from the group consisting of (G), (H), (J) and (K). (3) The multilayer film for packaging according to the above (1) or (2), wherein the multilayer film is a film for prepacking or heat sealing packaging.

<< Outer Layer Resin Composition >> The ethylene / vinyl acetate copolymer used as the component (A) of the outer layer resin composition in the present invention is a copolymer of ethylene and vinyl acetate, and contains vinyl acetate. The amount is 10 to 30% by weight, preferably 10 to 20% by weight, the melt flow rate (MFR) at 190 ° C. and a load of 2.16 kg is 0.5 to 3%.
It is an ethylene / vinyl acetate copolymer of 0 g / 10 min, preferably 1 to 10 g / 10 min.

M of ethylene / vinyl acetate copolymer (A)
If the FR is less than 0.5 g / 10 min, the extrudability decreases, while if it exceeds 30 g / 10 min, the strength of the finally obtained multilayer film is insufficient, and the multilayer film tends to be broken during packaging. When the content of vinyl acetate is less than 10% by weight, the film is hard and difficult to elongate, and the transparency is lowered. On the other hand, when the content exceeds 30% by weight, the strength is insufficient, and the multilayer film is easily broken at the time of packaging. .

As the ethylene / vinyl acetate copolymer (A), one type of ethylene / vinyl acetate copolymer having the above-mentioned physical properties may be used alone, or the ethylene / vinyl acetate copolymer may be used so as to have the above physical properties. Two or more polymers can be used in combination. In the latter case, the copolymers within the above range may be used in combination, or an ethylene / vinyl acetate copolymer outside the above range may be partially contained.

The content of the ethylene / vinyl acetate copolymer (A) in the outer layer resin composition is 99.5 to 90% by weight, preferably 99.5 to 92% by weight, more preferably 99 to 9% by weight.
5% by weight.

The antifogging agent used as the component (B) of the outer layer resin composition is a chemical compounded to prevent water in the air from condensing and fogging on the surface of the film.
There is no particular limitation as long as it makes the surface of the film hydrophilic and spreads generated water droplets, and those generally used as antifoggants can be used as they are.

Surfactants such as sorbitan monooleate, sorbitan monolaurate, sorbitan monobehenate, sorbitan monostearate, etc .; sorbitan fatty acid esters; glycerin monooleate; Glycerin fatty acid esters such as glycerin monostearate; diglycerin monooleate, diglycerin sesquilaurate, diglycerin sesquiolate, tetraglycerin monooleate, tetraglycerin monostearate, hexaglycerin monolaurate, hexaglycerin monooleate, Polyglycerin fatty acid esters such as degaclyserine monooleate and decaglycerin monolaurate; polyoxyalkylene ethers such as polyoxyethylene lauryl ether; lauryldiethano Such fatty amines two fatty acid amides such as oleic acid amide, such as triethanolamine, but are exemplified,
They are not limited thereto, and they are used alone or as a mixture.

The component (B) is 0.5 to 10% by weight, preferably 0.5 to 8% by weight of the outer layer resin composition.
More preferably, the content is 1 to 5% by weight. When the blending ratio of the anti-fogging agent (B) is less than 0.5% by weight, no anti-fogging effect can be obtained. I do.

The outer layer resin composition of the present invention contains a weathering stabilizer, a heat stabilizer, an antistatic agent, an antislip agent, an antiblocking agent, a lubricant, a pigment, a dye, as long as the object of the present invention is not impaired. Additives such as a nucleating agent, a plasticizer, an antioxidant, a hydrochloric acid absorbent, and an antioxidant may be added as needed.

The outer layer resin composition of the present invention can be produced by using a known method, for example, by the following method. 1) The component (B) is preliminarily mixed with a part of the component (A), and a masterbatch is prepared using an extruder, a kneader or the like, and this is mixed with the remaining component (A) and other components to be added as required. A method of mixing and mechanically blending using an extruder, a kneader or the like. 2) A method of mechanically blending the components (A) and (B), and other components added as desired, using an extruder, a kneader or the like. 3) Dissolve the components (A) and (B), and other components added as desired, in a suitable good solvent (for example, a hydrocarbon solvent such as hexane, heptane, decane, cyclohexane, benzene, toluene, and xylene). And then removing the solvent. 4) A method in which components (A) and (B), and other components added as required, are separately dissolved in a suitable good solvent, then mixed, and then the solvent is removed. 5) A method in which the above methods 1) to 4) are combined. Among the above manufacturing methods, the method of preparing a master batch of 1) is preferable.

<< Inner Layer Resin Composition >> In the present invention, a composition containing a high melting point component [I] and a soft component [II] is used as the inner layer resin composition. As the high melting point component,
It is possible to use both (C) component and / or (D) component, which will be described later, or either resin. Flexible component (II)
As the resin, at least one resin selected from the group consisting of components (E) to (K) described below can be used. However, the components (C) and (F) are not used simultaneously. The reason for this, as described in the prior art,
This is because, when olefin-based polymers such as the component (C) and the component (F) are combined with each other, the two are compatible with each other, so that an intermediate property is exhibited.

In the present invention, the ethylene polymer used as the component (C) of the inner layer resin composition may be a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably 3 to 16 carbon atoms. A polymer,
The melt flow rate (ASTM D1238) at 0 ° C. and a load of 2.16 kg is 0.1 to 10 g / 10
Min, preferably 0.3 to 8 g / 10 min, more preferably 0.5 to 4 g / 10 min, and a density of 0.930 to 0.1 g / min.
980 g / cm ³ , preferably 0.930 to 0.965
g / cm ³ , more preferably 0.940 to 0.960 g
/ Cm ³ of the olefin polymer.

The ethylene polymer used as the component (C) has a crystallinity of about 40 to 7 by X-ray diffraction.
About 0%, ethylene unit is a main component, for example, 90 to 10
0 mol%, preferably 95 to 100 mol%, more preferably 97 to 100 mol% is desirable.

The α-olefin copolymerized with ethylene includes propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene,
-Decene, 3-methyl-1-butene, 4-methyl-1-
Penten and the like are exemplified. The α-olefin as a comonomer is not limited to one type, and two or more types can be used like a terpolymer.

The ethylene polymer used as the component (C) can be obtained by polymerizing or copolymerizing ethylene or ethylene and an α-olefin in a gas phase or a liquid phase, usually in the presence of a transition metal catalyst. it can. There is no particular limitation on the catalyst for production, for example, Ziegler type catalyst, Phillips type catalyst, metallocene type catalyst and the like can be used,
Metallocene-type catalysts are preferred. The polymerization method is not particularly limited, and the polymerization can be performed by a polymerization method such as a gas phase method, a solution method, and a bulk polymerization method. As the component (C), a commercially available product may be used.

In the present invention, the propylene-based polymer used as the component (D) of the inner layer resin composition is a polymer containing propylene as a main monomer, and has a temperature of 230.degree.
Melt flow rate (MFR) under a load of 6 kg is 0.1 to 100 g / 10 min, preferably 0.5 to 20 g
/ 10 minutes, more preferably 1 to 10 g / 10 minutes,
It is a propylene-based polymer having a density of 0.880 to 0.920 g / cm ³ , preferably 0.890 to 0.915 g / cm ³ . The propylene-based polymer used as the component (D) preferably has a propylene content of 80% by mole or more and a crystallinity by X-ray diffraction method of 70% or less. Other monomers to be copolymerized with propylene include ethylene and other α-olefins having 4 to 20 carbon atoms.
The polymerization method of the propylene-based polymer (D) is not limited, either.
The same method as described for the component (C) can be used.

In the present invention, the block copolymer used as the component (E) of the inner layer resin composition is at least one polymer selected from the group consisting of blocks (e-1) to (e-3) described below. Block and a block (e-
It comprises at least one polymer block selected from the group consisting of 4) and (e-5), and may be hydrogenated.

The block (e-1) is a polymer block or copolymer block of styrene or a derivative thereof. The polymer or copolymer component constituting the block (e-1) is styrene or a derivative thereof. As the styrene derivative, specifically, α-methylstyrene,
1-vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4
-Benzylstyrene, 4- (phenylbutyl) styrene and the like. Styrene and α-methylstyrene are preferred as the polymer or copolymer component constituting the block (e-1).

The block (e-2) has 2 to 20 carbon atoms.
Α-olefin polymer block or copolymer block. As the polymer or copolymer component constituting the block (e-2), ethylene, propylene, 1-
Butene, 1-pentene, 1-hexene, 3-methyl-1
-Butene, 3-methyl-1-pentene, 3-ethyl-1
-Pentene, 4-methyl-1-pentene, 4-methyl-
1-hexene, 4,4-dimethyl-1-hexene, 4,
4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1- Α-olefins having 2 to 20 carbon atoms, such as eicosene. These can be used alone or in combination of two or more.

The polymer constituting the block (e-2) is an isoprene polymer or a butadiene polymer, which is a polymer obtained by hydrogenating a polymer having 1,4 bonds of 75% by weight or more. Is also good.

The block (e-3) is a copolymer block of styrene or a derivative thereof and an α-olefin having 2 to 20 carbon atoms. The copolymer components constituting the block (e-3) include the above-mentioned (e-1) and (e-
Compounds similar to the compounds exemplified as the polymer component constituting 2) can be mentioned.

The block (e-4) is an isoprene polymer block or an isoprene / butadiene copolymer block. The polymer or copolymer constituting the block (e-4) is an isoprene polymer or an isoprene / butadiene copolymer, and the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion shown below. Is 2
It is at least 5% by weight, preferably at least 30% by weight.

Embedded image

In the present invention, when the content of 1,2 bonds and 3,4 bonds in the isoprene polymer component of the block (e-4) is 25% by weight or more, a multilayer film for packaging excellent in finger pressure restoring property is provided. Can be obtained. The block (e-5) is a butadiene polymer block having a 1,2 and 3,4 vinyl bond content of 25% by weight or more, preferably 30% by weight or more.

The total proportion of the blocks (e-1) to (e-3) in the block copolymer (E) is preferably 5
-50% by weight, more preferably 10-45% by weight. That is, blocks (e-4) and (e-
The total proportion of 5) is preferably in the range of 95 to 50% by weight, more preferably 90 to 55% by weight. In the present invention, a hydrogenated block copolymer (E) is preferred. When the hydrogenated block copolymer (E) is used, a multilayer film for packaging excellent in weather resistance and heat resistance can be obtained.

The block copolymer (E) used in the present invention has a melt flow rate (MFR; ASTM D).
1238, 230 ° C, 2.16 kg load, the same applies hereinafter)
Is preferably in the range of 0.01 to 30 g / 10 min, more preferably 0.01 to 10 g / 10 min. When the block copolymer (E) having a melt flow rate in the above range is used, a multilayer film for packaging excellent in acupressure recovery can be obtained.

The block form of the block copolymer (E) used in the present invention includes blocks (e-1) to (e-1).
The (e-3) -block (e-4) or (e-5) -blocks (e-1) to (e-3) are most preferred, but not limited thereto. A diblock configuration or a configuration including four or more blocks may be used.

Such a block copolymer (E) can be produced, for example, by the following method. (1) A method in which styrene or a derivative thereof, isoprene or an isoprene-butadiene mixture is sequentially polymerized using an alkyllithium compound as an initiator. (2) A method of polymerizing styrene or a derivative thereof, followed by isoprene or a mixture of isoprene and butadiene, and coupling this with a coupling agent. (3) A method of sequentially polymerizing isoprene or an isoprene-butadiene mixture and then styrene or a derivative thereof using a dilithium compound as an initiator.

The details of the method for producing the above block copolymer (E) are described in, for example, JP-A-2-300250 and JP-A-3-300250.
No. 45646 and the like. Further, if the block copolymer (E) obtained by the above method is subjected to a hydrogenation treatment, a hydrogenated block copolymer (E) is obtained. The block to be hydrogenated is an isoprene polymer block, an isoprene / butadiene copolymer block (e-4), or a butadiene polymer block (e-
5).

In the present invention, the ethylene / α-olefin copolymer used as the component (F) of the inner layer resin composition is a copolymer of ethylene and an α-olefin having 3 to 20, preferably 3 to 16 carbon atoms. 1. 190 ° C .;
Melt flow rate at 16 kg load (ASTM
D 1238) is 0.1 to 10 g / 10 min, preferably 0.2 to 8 g / 10 min, more preferably 0.3 to 5 g / min.
10 minutes, density 0.850-0.895 g / cm
³ , preferably 0.860 to 0.890 g / cm ^{3 of} an ethylene / α-olefin copolymer.

Ethylene / α-olefin copolymer (F)
Is an ethylene unit as a main component, for example, 70 to 95 mol%, preferably 75 to 95 mol%, and has a crystallinity of about 0 to 50%, preferably 0 to 2% by an X-ray diffraction method.
A material having 0% physical properties is desirable.

As the α-olefin to be copolymerized with ethylene, the same as the α-olefin in the component (C) can be used. The ethylene / α-olefin copolymer (F) can be produced in the same manner as the component (C). A commercially available product can also be used.

The cyclic olefin resin used as the component (G) of the inner layer resin composition in the present invention includes:
(G-1) ethylene and / or α having 3 to 20 carbon atoms
A random copolymer of an olefin and a cyclic olefin represented by the above formula [1] or [2], (g-2) a ring-opening (copolymer) of a cyclic olefin represented by the formula [1] or [2]; ) A polymer or a hydrogenated product thereof, or (g-
3) Graft modified products of the above (g-1) or (g-2).

The cyclic olefin resin (G) used as the component (G) has a glass transition temperature (Tg) of + 30 ° C.
Hereinafter, preferably +30 to -30 ° C, 190 ° C,
Melt flow rate at a load of 2.16 kg (MF
R) is 0.1 to 10 g / 10 min, preferably 1 to 7 g / min.
10 minutes.

The cyclic olefin resin (G) contains 13
The intrinsic viscosity [η] measured in decahydronaphthalene at 5 ° C is 0.01 to 10 dl / g, preferably 0.05 to 10 dl / g.
2.0 dl / g, more preferably 0.4 to 1.2 dl / g
The softening temperature (TMA) measured by a thermal mechanical analyzer is usually 50 ° C. or lower, preferably +40 to −20 ° C. The softening temperature (TMA) was such that when a quartz needle having a diameter of 1.0 mm was placed on a sheet, a load of 49 g was applied, and the temperature was raised at a rate of 5 ° C./min, the needle penetrated 0.635 mm into the sheet. Temperature. It is desirable that the degree of crystallinity measured by the X-ray diffraction method is usually 0 to 50%, preferably 0 to 20%.

As the cyclic olefin-based resin (G), those having all the above physical properties in the preferable range are preferable, but those having certain physical properties in the preferable range and other physical properties in the wider range than the preferable range can also be used. .

First, the cyclic olefin used in forming the above-mentioned cyclic olefin resin (G) will be described. As the cyclic olefin, a compound represented by the above formula [1] or [2] is used. In the above formula [1], n is 0 or 1, and m is 0 or a positive integer.

R ^{1 to} R ¹⁸ and R ^a and R ^b each independently represent an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group. Here, the halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Examples of the hydrocarbon group include an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon having 6 to 20 carbon atoms. And the like. More specifically, as the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group,
Examples of the dodecyl group and octadecyl group include halogenated alkyl groups in which at least a part of the hydrogen atoms forming the above-mentioned alkyl group is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Examples of the group include: Examples of the cycloalkyl group include a cyclohexyl group, and examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.

Further, in the above formula [1], R ¹⁵ and R ¹⁶
And R ¹⁷ and R ¹⁸ , R ¹⁵ and R ¹⁷ , R ¹⁶ and R ¹⁸ , R ¹⁵ and R ¹⁸ , or R ¹⁶ and R ¹⁷ are respectively bonded (jointly And a single or multiple ring may be formed, and the single or multiple ring thus formed may have a double bond. Specific examples of the monocyclic or polycyclic ring formed here include the following.

[0045]

Embedded image In the above examples, the carbon atoms numbered 1 or 2 represent the carbon atoms to which R ¹⁵ (R ¹⁶ ) or R ¹⁷ (R ¹⁸ ) are bonded in formula [1].

Further, R ¹⁵ and R ¹⁶ or R ¹⁷ and R ¹⁸
And may form an alkylidene group. Such an alkylidene group is usually an alkylidene group having 2 to 20 carbon atoms, and specific examples of such an alkylidene group include an ethylidene group, a propylidene group and an isopropylidene group.

Preferred examples of the cyclic olefin in the formula [1] include a cyclic olefin represented by the following formula [1-1].

Embedded image In the above formula [1-1], n, m and R ^{1 to} R ¹⁸ represent the same as in the above formula [1].

Further, as the cyclic olefin, a compound represented by the above formula [2] can also be used. In the above formula [2], m is 0 or a positive integer, h is 0 or a positive integer, and j and k are 0, 1 or 2
It is. Further, R ⁷ to R ¹⁵ and R ¹⁷ to R ^{1 8} is the formula [1]
Represents the same as Further, R ^{19 to} R ²⁷ each independently represent an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group and an alkoxy group.

Here, the halogen atom is the same as the halogen atom in the formula [1]. Further, R ^19-
As the hydrocarbon group for R ²⁷ , an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms,
Examples thereof include a cycloalkyl group having 3 to 15 carbon atoms and an aromatic hydrocarbon group having 6 to 20 carbon atoms. More specifically, as the alkyl group, a methyl group,
An ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group and an octadecyl group can be exemplified.As the halogenated alkyl group, an alkyl group as described above is formed. At least some of the hydrogen atoms are fluorine, chlorine,
Examples thereof include a group substituted with a bromine atom or an iodine atom.

Examples of the cycloalkyl group include a cyclohexyl group, and examples of the aromatic hydrocarbon group include an aryl group and an aralkyl group. Specific examples include a phenyl group, a tolyl group, and a naphthyl group. Group, benzyl group and phenylethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.

Here, the carbon atom to which R ¹⁷ and R ¹⁸ are bonded and the carbon atom to which R ²¹ is bonded or the carbon atom to which R ¹⁹ is bonded are directly or a carbon atom having 1 to 3 carbon atoms.
May be bonded via an alkylene group of That is, when the two carbon atoms are bonded via an alkylene group, the groups represented by R ¹⁷ and R ²¹ , or the groups represented by R ¹⁸ and R ¹⁹ cooperate with each other. , a methylene group (-CH ₂ -), ethylene group (-CH ₂ CH ₂ -)
Alternatively, it forms any alkylene group among the trimethylene groups (—CH ₂ CH ₂ CH ₂ —).

When j = k = 0, R ²³ and R ²⁰ or R ²³ and R ²⁷ may be bonded to each other to form a monocyclic or polycyclic aromatic ring. Examples of the monocyclic or polycyclic aromatic ring in this case include R ²³ and R ²³ when j = k = 0.
^The following groups, in which ²⁰ further forms an aromatic ring, can be mentioned.

Embedded image In the above formula, h represents the same as h in Formula [2].

As the cyclic olefin represented by the above formula [1] or [2], specifically, bicyclo
[2.2.1] Hept-2-ene or its derivative, tetracyclo
[4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene or a derivative thereof, hexacyclo ^{[6.6.1.1 3,6 .1 10,13 .0 2,7 .0} 9,14] to -4 Putadesen or a derivative thereof, octacyclo [8.8.0.1 ^2,9 .1
^4,7 .1 ^11,18 .1 ^13,16 .0 ^3,6 .0 ^12,17] -5-docosene or derivatives thereof, pentacyclo [6.6.1.1 ^3,6 .0 ^{2, 7} .0 ^{9, 14} ] -4-hexadecene or a derivative thereof, heptacyclo-5-eicosene or a derivative thereof, heptacyclo-5-eneeicosene or a derivative thereof, tricyclo [4.3.0.1 ^2,5 ] -3-decene or a derivative thereof, tricyclo [1.4 .0.1 ^2,5] -3-undecene or its derivative, pentacyclo [6.5.1.1 ^{3, 5} .0
^2,7 .0 ^3,13] -4-pentadecene or derivatives thereof, pentaerythritol cyclopentadiene decadiene, or a derivative thereof, pentacyclo ^{[7.4.0.1 2,5 .1 9,12 .0 8,13]} -3- pentadecene or its derivatives to, Putashikuro [8.7.0.1 ^3,6 .1 ^10,17 .1 ^12,15 .0
^2,7 .0 ^11,16] -4-eicosene or derivatives thereof, Nonashikuro ^{[10.9.1.1 4,7 .1 13,20 .1 15,18 .0} 3,8 .0 2,10 .0 12,21 .0
^{14, 13]} -5-pentacosene or its derivative, pentacyclo ^{[8.4.0.1 2,5 .1 9,12 .0 8,13]} -3- hexadecene or Putashikuro derivative thereof to, [8.8.0.1 ^4,7 .1 ^11,18 .1 ^13,16 .0
^3,8 .0 ^12,17] N'eikosen or derivative thereof to 5, Nonashikuro ^{[10.10.1.1 5,8 .1 14,21 .1 16,19 .0} 2,11 .0 4,9 .0
^{13, 22} .0 ^15,20] -5-hexacosenoic or derivatives thereof, 1,4
Methano-1,4,4a, 9a-tetrahydrofluorene or its derivative, 1,4-methano-1,4,4a, 5,10,10a-hexahydroanthracene or its derivative, and cyclopentadiene-acenaphthylene adduct Can be mentioned.

The cyclic olefin represented by the above formula [1] or [2] can be produced by a Diels-Alder reaction between cyclopentadiene and an olefin having a corresponding structure. These cyclic olefins are
They can be used alone or in combination of two or more.

The cyclic olefin resins (G) of (g-1) to (g-3) can be prepared by using the cyclic olefin represented by the above formula [1] or [2], for example, as described in JP-A-60-1687.
08, JP-A-61-120816, JP-A-61-115912, JP-A-61-115916
JP, JP-A-61-271308, JP-A-61-271308
-272216, JP-A-62-252406, JP-A-62-252407, JP-A-64-1
No. 06, JP-A-1-156308 and JP-A-1-197511, etc., according to the method proposed by the present applicant and by appropriately selecting conditions.

(G-1) α-Olefin / Cyclic Olefin Random Copolymer Used as the cyclic olefin resin (G) (g)
-1) The α-olefin / cyclic olefin random copolymer usually contains 70 to 99.000 structural units derived from ethylene and / or an α-olefin having 3 to 20 carbon atoms.
It contains 9 mol%, preferably 75 to 99.5 mol%, of a structural unit derived from a cyclic olefin in an amount of 0.1 to 30 mol%, preferably 0.5 to 25 mol%. . The α-olefin composition and the cyclic olefin composition are measured by ¹³ C-NMR.

As the α-olefin having 3 to 20 carbon atoms, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1 -Pentene, 4-methyl-1-pentene, 4-methyl-1-hexene,
4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene,
3 carbon atoms such as 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene
To 20 α-olefins. Among ethylene and α-olefins having 3 to 20 carbon atoms, ethylene is preferred.

In the (g-1) α-olefin / cyclic olefin random copolymer, the structural units derived from the α-olefin and the structural units derived from the cyclic olefin are arranged randomly. And has a substantially linear structure. The fact that this copolymer is substantially linear and has substantially no gel-like cross-linked structure should be confirmed by dissolving this copolymer in an organic solvent and containing no insoluble matter. Can be. For example, when the intrinsic viscosity [η] is measured, it can be confirmed by completely dissolving the copolymer at 135 ° C. in decahydronaphthalene.

(G-1) In the α-olefin / cyclic olefin random copolymer, at least a part of the structural units derived from the cyclic olefin represented by the above formula [1] or [2] has the following structure, respectively. Formula [1-a]
Or, it is considered to have the structure represented by [2-a]. Further, it is considered that at least a part of the cyclic olefin represented by the formula [1-1] has a structure represented by the following structural formula [1-1-a].

[0060]

Embedded image In the above formulas [1-a] and [1-1-a], n, m,
q, R ^{1 to} R ¹⁸ and R ^a and R ^b represent the same as in the above formula [1]. In the formula [2-a], m, h, j, k,
R ^{7 to} R ¹⁵ and R ^{17 to} R ²⁷ represent the same as those in the above formula [2].

The (g-1) α-olefin / cyclic olefin random copolymer contains, if necessary, structural units derived from other copolymerizable monomers as long as the object of the present invention is not impaired. May be. Such other monomers include olefins other than the α-olefin or cyclic olefin as described above, norbornenes,
Non-conjugated dienes and the like can be mentioned. Specifically,
Cyclobutene, cyclopentene, cyclohexene, 3,4-
Dimethylcyclopentene, 3-methylcyclohexene, 2-
(2-methylbutyl) -1-cyclohexene, cyclooctene, cycloolefins such as 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene, 2-norbornene, 5-methyl-2
-Norbornene, 5-ethyl-2-norbornene, 5-isopropyl-2-norbornene, 5-n-butyl-2-norbornene, 5-
Norbornenes such as isobutyl-2-norbornene, 5,6-dimethyl-2-norbornene, 5-chloro-2-norbornene, 5-fluoro-2-norbornene, 1,4-hexadiene, 4-methyl-1,4- Hexadiene, 5-methyl-1,4-hexadiene,
Examples include non-conjugated dienes such as 1,7-otatadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and 5-vinyl-2-norbornene.

These other monomers can be used alone or in combination of two or more. (G-1)
In the α-olefin / cyclic olefin random copolymer, the constituent units derived from other monomers as described above may be contained in an amount of usually 20 mol% or less, preferably 10 mol% or less.

(G-1) The α-olefin / cyclic olefin random copolymer is prepared by using an α-olefin and a cyclic olefin represented by the formula [1] or [2] as disclosed in the above publication. It can be manufactured by a method.
Among these, the copolymerization is carried out in a hydrocarbon solvent, and a vanadium-based catalyst formed from a vanadium compound and an organic aluminum compound soluble in the hydrocarbon solvent as a catalyst, a titanium compound formed from a titanium compound and an organic aluminum compound are used as a catalyst. Using a zirconium complex formed from an aluminoxane and a zirconium complex having a polydentate compound in which at least two conjugated cycloalkadienyl groups are bonded via a lower alkylene group as a ligand (G-1) α-olefin ・
It is preferred to produce a cyclic olefin random copolymer.

(G-2) Ring-opening (co) polymer of cyclic olefin (g-2) Ring-opening (co) polymer of cyclic olefin is a cyclic olefin represented by the above formula [1] or [2]. It is considered that at least a part of the structural unit has a structure represented by the following formula [1-b] or [2-b]. The formula [1-
It is considered that at least a part of the cyclic olefin represented by the formula [1] has a structure represented by the following formula [1-1-b].

[0065]

Embedded image In the above formulas [1-b] and [1-1-b], n, m,
q, R ^{1 to} R ¹⁸ and R ^a and R ^b represent the same as in the above formula [1]. In the formula [2-b], m, h, j, k,
R ^{7 to} R ¹⁵ and R ^{17 to} R ²⁷ represent the same as those in the above formula [2].

The cyclic olefin ring-opened (co) polymer (g-
2) contains the above-mentioned cyclic olefin as an essential component, but may contain another copolymerizable unsaturated monomer component if necessary, as long as the object of the present invention is not impaired. . Examples of the unsaturated monomer which may be optionally copolymerized include, for example, a cyclic olefin represented by the following formula [3].

[0067]

Embedded image In the above formula [3], R ²⁸ and R ²⁹ are a hydrogen atom, a hydrocarbon group or a halogen atom, and may be the same or different. Also, t is an integer of 2 or more,
When R ²⁸ and R ²⁹ are repeated a plurality of times, they may be the same or different.

Examples of the monomer component represented by the above formula [3] include cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclononene, cyclodecene, methylcyclopentene, methylcyclohexene, methylcycloheptene, methylcyclooctene, methylcyclononene , Methylcyclodecene, ethylcyclopentene, ethylcyclobutene, ethylcyclooctene, dimethylcyclopentene, dimethylcyclohexene, dimethylcycloheptene, dimethylcyclooctene, trimethylcyclodecene, 2- (2-methylbutyl) -1
-Cyclohexene and the like.

As the unsaturated monomer which may be optionally copolymerized in addition to the above formula [3], specifically, 2,3,3a, 7a-tetrahydro-4,7-methano-1H-indene, Examples include cyclic olefins such as 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene. Such unsaturated monomers which may be optionally copolymerized may be used alone or in combination. Usually, the unsaturated monomer is used in an amount of 100 mol% of the cyclic olefin-based ring-opening (co) polymer (g-2). It is used in an amount of less than 50 mol%.

Such a ring-opened (co) polymer (g-2)
Can be manufactured by the manufacturing method disclosed in the above publication. Specifically, it is obtained by polymerizing or copolymerizing a cyclic olefin represented by the above formula [1] or [2] in the presence of a ring-opening polymerization catalyst. As such a ring-opening polymerization catalyst, a catalyst comprising a metal halide selected from ruthenium, rhodium, palladium, osmium, iridium or platinum, a nitrate or an acetylacetone compound, and a reducing agent, or titanium,
A catalyst comprising a metal halide selected from palladium, zirconium, molybdenum or the like or an acetylacetone compound and an organoaluminum compound can be used.

The hydrogenated product of the (g-2) ring-opening (co) polymer can be obtained by treating the (g-2) ring-opening (co) polymer obtained as described above with the presence of a conventionally known hydrogenation catalyst. It is a hydrogenated product obtained by hydrogenation below. In the hydrogenated product of the (g-2) ring-opened (co) polymer, at least a part of the structural units derived from the cyclic olefin represented by the formula [1] or [2] has the following formula [ It is considered to have the structure represented by 1-c] or [2-c].
Further, it is considered that at least a part of the cyclic olefin represented by the formula [1-1] has a structure represented by the following formula [1-1-c].

[0072]

Embedded image In the above formulas [1-c] and [1-1-c], n, m,
q, R ^{1 to} R ¹⁸ and R ^a and R ^b represent the same as in the above formula [1]. In the formula [2-c], m, h, j, k,
R ^{7 to} R ¹⁵ and R ^{17 to} R ²⁷ represent the same as those in the above formula [2].

(G-3) Graft-modified product The graft-modified product of (g-3) is the above-mentioned (g-
1) Graft modification obtained by graft-modifying an α-olefin / cyclic olefin random copolymer or (g-2) a ring-opening (co) polymer of a cyclic olefin or a part of a hydrogenated product thereof with a modifier. Things.

Examples of the modifier include unsaturated carboxylic acids such as acrylic acid, maleic acid, and maleic anhydride, and derivatives thereof such as acid anhydrides and alkyl esters of unsaturated carboxylic acids. In the graft-modified product (g-3), the content of the structural unit derived from the modifying agent is usually 10 mol% or less.

The graft-modified (g-3) is as follows:
A modifier is added to (g-1) an α-olefin / cyclic olefin random copolymer or (g-2) a ring-opened (co) polymer of a cyclic olefin or a hydrogenated product thereof so as to obtain a desired modification rate. It can be produced by blending and graft-polymerizing, or it can be produced by preparing a modified product having a high modification rate in advance, and then mixing the modified product with an unmodified cyclic olefin-based resin.

The cyclic olefin resin used as the component (G) is mainly composed of a resin selected from the group consisting of the above (g-1), (g-2) and (g-3). Yes, (g-1), (g-2) or (g-3)
Or a combination of two or more of these resins. (G-1),
A resin composition in which another resin is mixed with the resin of (g-2) or (g-3) may be used. Among these, (g-1) α-olefin / cyclic olefin random copolymer, particularly ethylene / cyclic olefin random copolymer, is preferably used as the cyclic olefin resin (G).

The aromatic copolymer used as the component (H) of the inner layer resin composition in the present invention is a copolymer of an aromatic monomer and ethylene and / or another α-olefin, A transition temperature of + 30 ° C. or lower, preferably +30 to −30 ° C., 190 ° C., load 2.16
0.1kg melt flow rate (MFR)
It has physical properties of 10 g / 10 minutes.

The aromatic monomers constituting the aromatic copolymer (H) include styrene, α-methylstyrene,
-Vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-
Benzylstyrene, 4- (phenylbutyl) styrene and the like can be mentioned. The other α-olefin other than ethylene constituting the aromatic copolymer (H) may have the same carbon number of 3 as the α-olefin constituting the component (C).
To 20 α-olefins.

The content of the aromatic monomer in the aromatic copolymer (H) is 0.1 to 50 mol%, preferably 1 to 50 mol%.
The content of 50 mol%, ethylene and other α-olefin is preferably 99.9 to 50 mol%, and more preferably 99 to 50 mol%. The aromatic copolymer (H) is represented by X
It is desirable that the crystallinity by the line diffraction method is usually 0 to 50%, preferably 0 to 40%.

The olefin copolymer used as the component (J) of the inner layer resin composition in the present invention is an olefin copolymer composed of propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms. is there. Carbon number 5
Α-olefin components of 1 to 12, 1-pentene,
3-methyl-1-butene, 1-hexene, 4-methyl-
Examples thereof include 1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene and 1-dodecene. These can be used alone or in combination of two or more.

The composition of the components constituting the olefin copolymer (J) is as follows: propylene 10 to 85 mol%, preferably 15 to 70 mol%, 1-butene 3 to 60 mol%, preferably 5 to 50 mol% Α-olefin having 5 to 12 carbon atoms is 10 to 85 mol%, preferably 15 to 70 mol%. When the content of each component is in the above range, a multi-layer film for packaging excellent in acupressure recovery can be obtained. The intrinsic viscosity [η] of the olefin copolymer (J) measured at 135 ° C. in decahydronaphthalene is 0.5 to 6 dl / g, preferably 0.5 to 5 dl / g, more preferably 1 to 4 dl / g.
It is.

The olefin copolymer (J) desirably has a crystallinity of 20% or less, preferably 15% or less, as measured by X-ray diffraction. When the crystallinity is in the above range, a multilayer film for packaging excellent in finger pressure restoring property can be obtained. The olefin copolymer (J) has a dynamic elastic modulus (E ') measured at 25 ° C. of 5 × 10 ^{7 to} 5 × 10 ⁹ d.
yn / cm ² , particularly preferably 1 × 10 ^{8 to} 5 × 10 ⁹ d
yn / cm ² and the loss factor at 25 ° C. (t
anδ) is preferably 0.4 or more, particularly preferably 0.5 or more. When the dynamic elastic coefficient (E ′) and the loss coefficient (tan δ) are in the above ranges, a multilayer film for packaging having particularly excellent acupressure recovery can be obtained.

The dynamic elastic coefficient (E ') and the loss coefficient (tan δ) were measured by the following methods. That is, the polymer is hot-pressed at 200 ° C. and rapidly cooled by a cold press to form a sheet (thickness: 1 mm). After leaving this sheet for one day or more, it is cut into a test piece having a length of 3 cm and a width of 3 mm. This test piece was measured with a dynamic viscoelasticity meter (manufactured by Toyo Baldwin Co., Ltd., RHEO-VIBRON DDV).
-II type), frequency 110Hz, dynamic displacement 1.6 ×
The measurement is performed under the condition of 10 ⁻³ cm.

The olefin copolymer (J) has a boiling point n
A heptane insoluble content of 5% by weight or less, preferably 4% by weight
And the acetone-soluble matter at 25 ° C. is desirably 3% by weight or less, preferably 2.5% by weight or less. The boiling n-heptane insoluble content is about 1 mm × 1 m
A small sample of about mx 1 mm and glass beads were placed in a cylindrical glass filter, and 14
It is calculated by a method of extracting time, and the weight% of the insoluble content is a value obtained by weighing the dissolved portion or the insoluble content. The acetone-soluble matter at 25 ° C. is obtained by dissolving 15 g of a sample in 250 ml of n-decane (130 ° C.), throwing it into 500 ml of acetone to precipitate an acetone-insoluble polymer, collecting the filtrate by filtration, and then collecting the filtrate. This value is obtained by adding 300 ml of water, separating the n-decane layer and the water-acetone layer with a separating funnel, and concentrating the n-decane layer.

The butene-based polymer used as the component (K) of the inner layer resin composition in the present invention is a polymer containing 1-butene as a main monomer,
Melt flow rate at g load (ASTM D 1
238) is 0.1 to 5 g / 10 min, preferably 0.5 to 5 g / 10 min.
5 g / 10 min, more preferably 0.5 to ³ g / 10 min, and a density of 0.890 to 0.915 g / cm ³ , preferably 0.895 to 0.910 g / cm ³ , more preferably 0.1 to 0.910 g / cm ³ . 895-0.905 g / cm ³ butene polymer. The butene-based polymer used as the component (K) is preferably one in which 1-butene is 70 mol% or more and the degree of crystallinity by X-ray diffraction is 65% or less. Other monomers to be copolymerized with 1-butene include ethylene, propylene and other α-olefins having 5 to 20 carbon atoms. The method for polymerizing the butene-based polymer (K) is not limited, and the same method as described for the component (C) can be used.

The mixing ratio of the high melting point component [I] and the softening component [II] in the inner layer resin composition is 5 to 9 for the high melting point component [I].
5% by weight, preferably 10-90% by weight of the soft component [I
I] It is desirably 95 to 5% by weight, preferably 90 to 10% by weight. When the high melting point component [I] and the soft component [II] are mixed in the above mixing ratio, a multilayer film for packaging excellent in finger pressure restoring property and perforation resistance can be obtained.

As the inner layer resin composition, the softening temperature is relatively higher than the softening temperature of the outer layer resin composition.
It is preferable to use a resin composition that is at least 5 ° C. higher. When using the inner layer resin composition in which the softening temperature of the inner layer resin composition is relatively higher than the softening temperature of the outer layer resin composition, the outer layer is melted, but the inner layer is not melted and heat-sealed while maintaining the shape. And a better heat sealing property can be obtained.

As the inner layer resin composition, the melting point (hereinafter referred to as DSC melting point) measured by a differential calorimeter (DSC) is relatively higher than the DSC melting point of the outer layer resin composition.
It is preferable to use a resin composition which is preferably at least 15 ° C. or higher. When the inner layer resin composition having the DSC melting point of the inner layer resin composition relatively higher than the DSC melting point of the outer layer resin composition is used, the outer layer is melted, but the inner layer is not melted and heat-sealed while maintaining the shape. And a better heat sealing property can be obtained.

Further, as the inner layer resin composition, it is preferable to use a resin composition having a DSC melting point relatively higher than the softening temperature of the outer layer resin composition, preferably higher than 15 ° C., more preferably higher by 20 to 80 ° C. . When the inner layer resin composition having a DSC melting point of the inner layer resin composition relatively higher than the softening temperature of the outer layer resin composition is used, the outer layer is melted, but the inner layer is not melted and heat-sealed while maintaining the shape. And excellent heat sealing properties can be obtained.

The inner layer resin composition may contain the anti-fogging agent exemplified as the anti-fogging agent (B) in an amount of 0.5 to 10% by weight based on the whole inner layer resin composition.
In addition, the inner layer resin composition, within a range that does not impair the object of the present invention, a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an anti-slip agent, an anti-blocking agent, a lubricant, a pigment, a dye,
Additives such as a nucleating agent, a plasticizer, an antioxidant, a hydrochloric acid absorbent, and an antioxidant may be added as necessary.

The inner layer resin composition may be prepared by mechanically blending the components (C) to (K) and other components added as necessary, or by dissolving and mixing in a solvent and then removing the solvent. It can be manufactured by the same method as described for the composition.

<< Multilayer Film >> The multilayer film of the present invention has a three-layer structure of an outer layer / inner layer / outer layer in which an outer layer made of the outer layer resin composition is laminated on both surfaces of an inner layer made of the inner layer resin composition. It is a structural film. The outer layers on both sides of the multilayer film may use surface layers having the same composition, or may use compositions belonging to the above composition range but having different component compositions.

The thickness of the multilayer film of the present invention is generally 5 to 30 μm, preferably 10 to 20 μm in total thickness. When the thickness of the film is less than 5 μm, the handleability of the film is significantly reduced due to a decrease in strength and waist of the film,
If it exceeds 30 μm, the stress at the time of stretching the film becomes large, and the tray and the packaged object are easily deformed, which is not preferable. The thickness of the inner layer of the multilayer film of the present invention is preferably 10 to 80% of the total thickness of the film, and specifically 0.5 to 80%.
Those having a thickness of 24 μm, preferably 1 to 16 μm are suitable. Here, the thickness of the film of the inner layer is 1 of the film thickness.
If it is less than 0%, the effect of improving perforation resistance and finger pressure restoring property cannot be expected, and if it exceeds 80%, heat sealability and transparency may be impaired. The thickness of the outer layer is approximately equal on both sides, and each is 1 to 20 μm, preferably 2 to 20 μm.
It is desirable that the thickness be 10 μm.

The method for producing such a multilayer film includes a molding method conventionally used using each of the above-mentioned resin compositions,
Specifically, it can be manufactured by laminating by ordinary inflation molding, air-cooled two-stage inflation molding, T-die film molding, extrusion lamination molding, or the like. Among these, inflation molding having a good balance of vertical and horizontal properties is preferable.

The multilayer film for packaging of the present invention thus obtained has a suitable elongation elasticity and adhesiveness, and is excellent in transparency, cutability, heat sealability, antifogging property, perforation resistance and finger pressure recovery property. Therefore, it can be used as a film for prepack and other films for packaging.

When the multi-layer film for packaging of the present invention is used as a film for pre-packing, an object to be packaged, such as food, is placed on a plastic tray, or is packaged with the multi-layer film of the present invention naked, so that the e-package has a moderate elongation elasticity. It can be stretch-wrapped in a shape that fits its shape without damaging the object, and can be sealed and adhered with an appropriate heat-sealing property to maintain the packaged state without using other fixing means. In this case, it is possible to cut the film at an arbitrary place and perform packaging by an excellent cut property, and the package body can be visually recognized by the transparency, and the inside of the package is clouded by the anti-fog property. Absent. In addition, it is excellent in perforation resistance and finger pressure restoring property, making it difficult to open holes and leaving no trace even when pressed with a finger.

The multilayer film of the present invention can be used as a wrap film in the form of a film as it is, and has excellent heat sealing properties. Therefore, the multilayer film is formed into a bag, bag, or other heat seal packaging material to house the packaged object, or It can also be used as a lid for containers such as bottles and blister packs. In each case, the excellent characteristics as the packaging film as described above are obtained. By selecting a combination in which the softening temperature of the inner layer is higher than the softening temperature of the outer layer, more excellent heat sealing properties can be obtained.

The multilayer film for packaging according to the present invention is a packaging material having no problem in disposal treatment after use like conventional plasticized polyvinyl chloride and having no problem in food hygiene. This film can stretch-package various foods as a stretch film for food packaging, and can be widely used as a film for prepacking or heat-sealing packaging.

[0099]

As described above, since the multilayer film for packaging of the present invention is composed of a laminate of an outer layer and an inner layer made of a specific resin composition, it has a suitable elongation elasticity and adhesiveness, transparency,
An inexpensive packaging film having well-balanced performance, such as excellent cut properties, heat seal properties, anti-fog properties, perforation resistance, and finger pressure recovery properties, can be obtained.

Further, by using the above-mentioned multilayer film as a film for pre-packing or heat-sealing packaging, it is possible to stretch-wrap the product to be packaged in a state conforming to its shape without damaging the packaged product. In addition, the package is easy to pack due to the cut property, the contents are clearly visible in the package state, there is no fogging, there is no trace of pressing with a finger, heat sealing is easy, and holes are opened It is difficult to obtain an excellent package. Further, since the multilayer film for packaging of the present invention is made of a polyolefin-based polymer, there is no problem in disposal treatment after use like conventional plasticized polyvinyl chloride, and there is no problem in food hygiene.

[0101]

Embodiments of the present invention will be described below. The measurements and evaluations of the physical properties in the description of the present invention and the following examples were performed by the following methods. 1) MFR; ASTM D1238 2) Density; ASTM D1505 3) Haze; ASTM D1003 4) Actual packaging test; Actual packaging test was performed using a packaging machine (Teraoka Seiko AW-2600 Jr.PE), and cutability and acupressure. Restorability and seal adhesion at each heater temperature were examined. 5) Measurement of softening temperature; 15 μm thickness by inflation or casting method
Was heat-sealed under the following conditions, and the heat-sealing strength was measured under the following conditions. The heat-sealing temperature at which the heat-sealing strength was 100 gf or more was defined as the softening temperature. Heat sealing conditions: pressure 2 kgf / cm ² , time 1 sec, width 5 mm Heat sealing strength measurement conditions: tensile, 23 ° C., crosshead speed 300 mm / min 6) Measurement of DSC melting point; resin or resin composition sample from 30 ° C. 10 ° C / mi
The temperature was raised to 200 ° C. at a speed of n and held for 5 minutes.
The temperature was lowered to 30 ° C. at a rate of 0 ° C./min, kept for 5 minutes, and the main peak when the temperature was raised at a rate of 10 ° C./min was determined as the DSC melting point.

Antifogging agent master batch Vinyl acetate content: 15% by weight, 190 ° C., load: 2.1
MFR at 6 kg is 2.8 g / 10 min.
A composition comprising 94% by weight of vinyl acetate copolymer (A), 5% by weight of diglycerin sesquilaurate, 0.75% by weight of polyoxyethylene lauryl ether, and 0.25% by weight of lauryl diethanolamine was prepared with a 30 mm diameter, L / D
= 26 using a twin-screw extruder at a resin temperature of 200 ° C.
The mixture was granulated and used as an antifogging agent master batch (B).

Example 1 An outer layer resin composition (softening temperature: 80 ° C., DSC melting point: 85 ° C.) was blended with 60% by weight of the ethylene / vinyl acetate copolymer (A) and 40% by weight of the antifogging agent master batch (B). ° C).

The butene-propylene copolymer (K) (1-
Butene content 78 mol%, crystallinity 39%, density 0.90
M at 0 g / cm ³ , 190 ° C., 2.16 kg load
FR 1.0 g / 10 min) 50% by weight and propylene
Ethylene-butene copolymer (D) (propylene content 9
5.2 mol%, butene content 1.6 mol%, crystallinity 55
%, Density 0.910 g / cm ³ , 230 ° C., load 2.1
An inner layer resin composition (softening temperature: 118 ° C., DS) was blended with 50% by weight of MFR (7.0 g / 10 min in 6 kg).
C melting point 135 ° C).

The above outer layer resin composition and inner layer resin composition were each extruded using three extruders having a diameter of 50 mm and L / D = 26.
The resin composition was extruded at a resin temperature of 200 ° C. and a blow-up ratio of 4.1 so that the inner layer resin composition became an intermediate layer.
A film having a size of / 5/5 μm and a total thickness of 15 μm was obtained. Using this film, film physical properties were evaluated by the method described above. Table 1 shows the results.

Example 2 In Example 1, the styrene block (e-1) -ethylenebutylene block (e-
5)-Triblock copolymer (E) of an olefin crystal block (e-2) 60% by weight and ethylene / hexene-1 copolymer (C) (ethylene content 96.6 mol%, crystallinity 63%, Density 0.931 g / cm ³ , 190 ° C.,
The same procedure was carried out except that 40 wt% of MFR 2.0 g / 10 min, softening temperature 116 ° C., DSC melting point 135 ° C.) under a load of 2.16 kg was blended to form an inner layer resin composition (DSC melting point 125 ° C.). The ethylene butylene block (e-) in the triblock copolymer (E) was used.
5) is a block obtained by hydrogenating a butadiene polymer block having a 1,4 bond content of 85% by weight. The olefin crystal block (e-2) is a block obtained by hydrogenating a butadiene polymer block having a 1,2-vinyl bond content of 40% by weight. Table 1 shows the results.

Example 3 In Example 1, the styrene block (e-1) -ethylenebutylene block (e) was used as the inner layer resin composition.
-5) -60% by weight of a triblock copolymer (E) of an olefin crystal block (e-2) and the propylene
The same procedure was performed except that 40% by weight of an ethylene / butene copolymer (D) was blended to form an inner layer resin composition (DSC melting point: 135 ° C.). Table 1 shows the results.

Example 4 In Example 1, ethylene / ethylene resin was used as the inner layer resin composition.
Norbornene copolymer (G) (glass transition temperature −5 ° C.,
DSC melting point 50 ° C., ethylene content 83.9 mol%, 19
MFR 5.4 g / 10 at 0 ° C. and 2.16 kg load
Min) 60 wt% and 40 wt% of the propylene / ethylene / butene copolymer (D) were blended to give an inner layer resin composition (DSC melting point: 135 ° C). Table 1 shows the results.

Example 5 In Example 1, an ethylene resin was used as the inner layer resin composition.
Butene copolymer (F) (Density 0.885 g / cm ³ , D
SC melting point 76 ° C, ethylene content 88 mol%, 190 ° C,
MFR 0.5 g / 10 min under a load of 2.16 kg) 6
The same procedure was carried out except that 0% by weight and 40% by weight of the propylene / ethylene / butene copolymer (D) were blended to form an inner layer resin composition (DSC melting point: 137 ° C.). Table 1 shows the results.

Example 6 In Example 1, ethylene / ethylene resin was used as the inner layer resin composition.
Styrene copolymer (H) (glass transition temperature -5 ° C, DS
C Melting point 38 ° C, ethylene content 82 mol%, 190 ° C, load 2.16 kg, MFR 4.3 g / 10 min) 60
% By weight and 40% by weight of the propylene / ethylene / butene copolymer (D) to form an inner layer resin composition (D
(SC melting point 135 ° C.). Table 1 shows the results.

Example 7 In Example 1, a propylene / 4-methylpentene-1-butene copolymer (J) (intrinsic viscosity [η] 1.25 dl / g, crystallinity 3. 1%, 2
Dynamic elastic modulus (E ') at 5 ° C. 4.5 × 10 ⁸ dy
n / cm ² , loss factor (tan δ) 1.04, glass transition temperature 25 ° C., DSC melting point 47 ° C., propylene content 46
Mol%, 4-methylpentene-1 content 32 mol%, 19
MFR 4.5 g / 10 at 0 ° C. and 2.16 kg load
Min) 60 wt% and the propylene / ethylene / butene copolymer (D) 40 wt% were blended to give an inner layer resin composition (DSC melting point 134 ° C.). Table 1 shows the results.

Comparative Example 1 In Example 1, without using the inner layer resin composition,
Example 1 except that the outer layer resin composition was used to form three layers.
The same was done. Table 1 shows the results.

Comparative Example 2 In Example 1, 60% by weight of the ethylene / butene copolymer (F) and 40% by weight of the ethylene / hexene-1 copolymer (C) were blended as the inner layer resin composition. The same procedure was performed except that the inner layer resin composition (DSC melting point: 93 ° C.) was used. Table 1 shows the results.

[0114]

[Table 1]

Notes on Table 1 The evaluation criteria are as follows. << Cutability >> ：: After tray packaging, the film can be cut without any problem by the film cutting blade of the packaging machine. ×: After the tray packaging, the film cannot be cut by the film cutting blade of the packaging machine. << Shiatsu pressure restoring property >> ：: Even if the film on the upper surface of the tray after packaging is lightly pressed with a finger, no trace of the finger remains. ：: Even if the film on the upper surface of the tray after packaging is lightly pressed with a finger, almost no finger mark remains. ×: When the film on the upper surface of the tray after packaging is lightly pressed with a finger, a finger mark is clearly left. << Seal Adhesion >> ：: The adhesion of the seal portion on the bottom surface of the tray after packaging is good, and the packaging state can be maintained. X: The packaging state cannot be maintained due to poor adhesion of the seal portion on the bottom of the tray after packaging, or the film on the bottom is melted and a hole is opened to maintain the packaging state.

From the results shown in Table 1, all of the multilayer films of the examples are excellent in transparency, film-cutting property, acupressure recovery property and seal adhesiveness. In particular, examples 2 to 7 are excellent in the acupressure recovery property. It can be seen that those of Comparative Examples 1 and 2 have remarkably poor cuttability, and holes are formed at the time of high-temperature heat sealing, which is insufficient as a packaging film.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI C08L 53/02 C08L 53/02

Claims (3)

[Claims] 1. A multilayer film for packaging, wherein an inner layer made of the following inner layer resin composition is laminated between outer layers made of the following outer layer resin composition. Outer layer resin composition: (A) a copolymer of ethylene and vinyl acetate, wherein the content of vinyl acetate is 10 to 30% by weight, 190 ° C,
99.5 to 90% by weight of an ethylene / vinyl acetate copolymer having a melt flow rate (MFR) at a load of 16 kg of 0.5 to 30 g / 10 min, and (B) 0.5 to 10% by weight of an antifogging agent. Inner layer resin composition: [I] (C) an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms,
The melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg is 0.1 to 10 g / 10 min, and the density is 0.9.
An ethylene polymer of ^{30 to} 0.980 g / cm ³ and / or (D) a melt flow rate (MFR) at 230 ° C. under a load of 2.16 kg of 0.1 to 100 g / 1.
0 minutes, a propylene-based polymer having a density of 0.880 to 0.920 g / cm ³ , [II] (E) a polymer block (e-1) of styrene or a derivative thereof, and an α-olefin having 2 to 20 carbon atoms. And at least one polymer block selected from the group consisting of styrene or a derivative thereof and a copolymer block of an α-olefin having 2 to 20 carbon atoms (e-3); An isoprene polymer block or an isoprene / butadiene copolymer block, wherein the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion is 25% by weight or more (e-4) ) And a butadiene polymer block having a 1,2 and 3,4 vinyl bond amount of 25% by weight or more. An optionally hydrogenated block copolymer comprising at least one polymer block selected from the group; (F) a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, Melt flow rate (MFR) at 0.16 ° C. and a load of 2.16 kg is 0.1 to 10 g / 1.
An ethylene / α-olefin copolymer having a density of 0.850 to 0.895 g / cm ³ for 0 minute; (G) (g-1) the following formula [1] or [2] [In the formula [1], n is 0 or 1, m is 0 or a positive integer, q is 0 or 1, and R ^{1 to} R
¹⁸ and R ^a and R ^b each independently represent an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group, and R ¹⁵ and R ¹⁶ are bonded to each other to form a monocyclic or polycyclic And the monocyclic or polycyclic ring may have a double bond, and R ¹⁵ and R ¹⁶ or R ¹⁷ and R ¹⁸ form an alkylidene group. You may. Here, when q is 0, the respective bonds are combined to form a 5-membered ring. ] [In the formula [2], m is 0 or a positive integer, and h
Is 0 or a positive integer; j and k are 0, 1 or 2; R ^{7 to} R ¹⁵ and R ^{17 to} R ¹⁸ each independently represent a group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group; Represents an atom or a group selected from R ^{19 to} R ²⁷
Each independently represents an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group and an alkoxy group. An α-olefin / cyclic olefin random copolymer comprising a copolymer of a cyclic olefin represented by the following formula: and ethylene and / or an α-olefin having 3 to 20 carbon atoms; (g-2) the formula [1] Or a ring-opened (co) polymer of a cyclic olefin represented by [2] or a hydrogenated product thereof,
And (g-3) a group consisting of the α-olefin / cyclic olefin random copolymer (g-1) or a ring-opened (co) polymer of a cyclic olefin or a graft modified product of a hydrogenated product thereof (g-2). At least one cyclic olefin resin selected from the group consisting of:
Hereinafter, the melt flow rate (MFR) is 0.1 to 10 g.
(H) a copolymer of an aromatic monomer and ethylene and / or another α-olefin having a glass transition temperature of 30 ° C. or less and a melt flow rate (MFR) Is 0.1
(J) a copolymer of propylene, 1-butene and an α-olefin having 5 to 12 carbon atoms, wherein the composition of each component is 10 to 85 mol of propylene %, 1-butene 3 to 60 mol% and α-olefin having 5 to 12 carbon atoms 10 to 85
Olefin copolymer having an intrinsic viscosity [η] of 0.5 to 6 dl / g as measured in decahydronaphthalene at 135 ° C., and (K) a melt flow rate at 190 ° C. under a load of 2.16 kg. At least one resin selected from the group of components (E) to (K) consisting of a butene-based polymer having a (MFR) of 0.1 to 5 g / 10 min and a density of 0.890 to 0.915 g / cm ³ [ However, the component (C) and the component (F) are not used simultaneously. And a resin composition comprising: 2. The mixing ratio of the inner layer resin composition is 5 to 95% by weight of the component (C) and / or (D), (E)
2. The packaging according to claim 1, wherein the content of at least one component selected from the group consisting of (F), (G), (H), (J) and (K) is 95 to 5% by weight. Multilayer film. 3. The multilayer film for packaging according to claim 1, wherein the multilayer film is a film for prepacking or heat sealing packaging.