JP2020199735A - Polyethylene resin composition and laminate - Google Patents

Abstract

To provide a polyethylene resin composition having excellent adhesiveness between a base material layer such as a polyethylene terephthalate resin layer and a barrier layer such as an aluminum foil without using an adhesive, and a laminate using the resin composition.SOLUTION: There is provided a resin composition for forming a resin layer (a) existing between a base material layer (b) and a barrier layer (c), which is a polyethylene resin composition (D) containing an ethylene/propylene copolymer (A) having a specific structural unit, MFR, density, and a total amount of vinyl and vinylidene in the ethylene/propylene copolymer, and contains 0 to 0.5 pts.wt. of an epoxidized vegetable oil (B) based on 100 pts.wt. of a resin component in the polyethylene resin composition (D). There is also provided a laminate using the polyethylene resin composition (D).SELECTED DRAWING: Figure 1

Description

The present invention relates to a polyethylene resin composition and a laminate. More specifically, a polyethylene resin composition having extremely good adhesiveness to a base material layer and a barrier layer, and a resin layer and a base material layer containing the resin composition. It relates to a laminate including a barrier layer.

Conventionally, as a base material for packaging, a polyamide resin having excellent transparency and mechanical strength, a polyethylene terephthalate resin which does not cause pitch shift even when tension is applied during printing due to its elasticity, a polypropylene resin having excellent moisture resistance, etc. Is used. In particular, polyethylene terephthalate resin base materials are used in a wide range of fields such as packaging films, magnetic tape films, optical films, and electronic component films because they are excellent in heat resistance, chemical resistance, and insulating properties. .. However, there are problems such as the heat sealing temperature is high and the packaging speed cannot be increased, the film shrinks during heat sealing and the packaging appearance deteriorates, the heat sealing strength is low, and the barrier property is low by itself. Therefore, these base materials are rarely used alone, and a composite film provided with a heat-sealing layer is usually used. As the heat seal layer, a layer using a polyethylene-based resin made of high-pressure low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), linear low-density polyethylene (LLDPE), or the like is widely used. .. Further, in order to improve the storage stability of the contents of packaging, containers, etc., a metal foil such as an aluminum foil having a barrier property and a metal-deposited film are used in combination with these composite films.

As a method for adhering the polyethylene-based resin layer to the base material, a dry laminating method, an extrusion laminating method, or the like is appropriately selected. In the dry laminating method, an isocyanate-based adhesive is dissolved in an organic solvent to form a solution, which is applied onto one substrate, the solvent is evaporated in a dryer, and then the other substrate is attached with a nip roll. It fits. Further, in the extrusion laminating method, a stable and high adhesive strength is required in both cases where an adhesive is applied or not.
When an adhesive is used, the adhesive strength between the layers of the laminate is maintained, but the manufacturing cost increases due to the large amount of adhesive used, the safety decreases due to the use of an organic solvent, and the environment is improved. There are problems such as residual odor in the final product. On the other hand, when an adhesive is not used, the adhesive strength between the layers of the laminated body is weakened, so that the package made of the laminated body is easily damaged and the quality as a packaging material is not stable.
Examples of resins having excellent adhesiveness include copolymers of ethylene and methyl acrylate (EMMA), copolymers of ethylene and acrylic acid (EAA), ionomers, and polymethyl methacrylate (PMMA). is there. However, the container using these resins has a drawback that the odor and elution components due to the decomposition of the resin are transferred to the contents, which causes deterioration of the quality of the contents, and also has a problem that it is expensive. There is.

Many attempts have been made to solve this problem, and for example, a method using a water-soluble adhesive without using a solvent-based adhesive has been proposed. Further, as a method using no adhesive, a method of introducing polar groups such as an acid anhydride group and a carboxyl group into polyolefin (see Patent Documents 1 and 2) and a method of using a polyolefin resin composition containing an epoxy compound (Patent). (See Documents 3 and 4), and a method of using polyethylene exhibiting specific physical properties (see Patent Documents 5 and 6) have been proposed.
However, when a water-soluble adhesive is used, the adhesive itself is generally water-soluble, so that the water resistance is inferior. Further, although the methods disclosed in Patent Documents 1, 2, 5 and 6 show an improvement in adhesive strength, they are insufficient as compared with the case where an adhesive is used. Further, in the method disclosed in Patent Documents 3 and 4, that is, in the conventional general resin composition containing low-density polyethylene as a main component, sufficient adhesion is sufficient even if a large amount of epoxidized vegetable oil is actually blended. It was difficult to demonstrate the sex.
Further, in particular, a composite film having a layer made of a metal foil or a metal vaporized film having a barrier property together with a polyethylene terephthalate layer is known, but both the adhesiveness to the polyethylene terephthalate layer and the adhesiveness to the metal are excellent. It was very difficult to obtain the adhesive resin composition.

Japanese Unexamined Patent Publication No. 57-157724 JP-A-59-75915 Japanese Unexamined Patent Publication No. 2000-37831 Japanese Unexamined Patent Publication No. 2016-22613 JP 2001-191452 JP-A-2002-19060

In view of the above problems, an object of the present invention is to provide a polyethylene resin composition having excellent adhesiveness between a base material layer such as a polyethylene terephthalate resin layer and a barrier layer such as aluminum foil without using an adhesive. An object of the present invention is to provide a laminate using the resin composition.

As a result of diligent studies to solve the above problems, the present inventor newly prototyped an ethylene / propylene copolymer having the physical properties of the new regions (a-1) to (a-4) shown below, and also It contains a predetermined amount of a main component of polyethylene and a sub-component of propylene having such specific characteristics, has a certain range of density and MFR, has a large amount of double bonds contained in the copolymer, and is branched. The polyethylene resin composition (D) containing a large number of ethylene / propylene copolymer (A) and epoxidized vegetable oil (B), preferably further containing a specific high-pressure radical polymerization low-density polyethylene (C), is extremely It was found that it has excellent adhesiveness, and the resin layer (a) using the resin composition (D) is directly formed between a base material layer such as polyethylene terephthalate and a barrier layer such as a metal foil. It has been found that the body has good adhesiveness and becomes a laminated body having excellent protection performance of the contents, and has completed the present invention.

That is, according to the first invention of the present invention, the resin composition for forming the resin layer (a) existing between the base material layer (b) and the barrier layer (c) is as follows (a). -1) The polyethylene resin composition (D) containing the ethylene / propylene copolymer (A) having the characteristics of (a-4), and the resin component 100 in the polyethylene resin composition (D). Provided is a polyethylene resin composition (D), which comprises 0 to 0.5 parts by weight of an epoxidized vegetable oil (B) with respect to parts by weight.
(A-1) Containing 80 to 98 mol% of a constituent unit derived from ethylene as a main component and 2 to 20 mol% of a constituent unit derived from propylene as an essential subcomponent, and forming a third α-olefin other than ethylene and propylene. The derived structural unit may be contained in an amount of 5 mol% or less as a sub-component (however, when the structural unit derived from the third α-olefin is contained, the structural unit derived from ethylene and the structural unit derived from propylene are used. The total of the structural units derived from the third α-olefin does not exceed 100 mol%.)
(A-2) MFR (190 ° C., 21.18 N load) 0.1 to 100 g / 10 minutes (a-3) Density 0.88 to 0.94 g / cm ³
(A-4) The total amount of vinyl and vinylidene in the ethylene / propylene copolymer is 0.35 (pieces / total 1000C) or more (however, the number of vinyl and vinylidene is the number of the main chain and side chains measured by NMR. It is the number per 1000 carbon atoms in total.)

Further, according to the second invention of the present invention, in the first invention, the polyethylene resin composition (D) has the following characteristics (c-1) to (c-2). Provided is a polyethylene resin composition (D), which comprises a density polyethylene (C).
(C-1) MFR (190 ° C., 21.18N load) 0.1 to 20 g / 10 minutes (c-2) Density 0.915 to 0.930 g / cm ³

Further, according to the third invention of the present invention, in the second invention, the ethylene / propylene copolymer (A) in the polyethylene resin composition (D) and the high-pressure radical polymerization method low-density polyethylene ( Provided is a polyethylene resin composition (D) characterized in that the content ratio (weight ratio A: C) of C) is 95 to 5: 5 to 95.

Further, according to the fourth invention of the present invention, in any one of the first to third inventions, the ethylene / propylene copolymer (A) further satisfies the following property (a-5). The polyethylene resin composition (D) is provided.
(A-5) The number of branches (Y) and the density (X) due to the comonomer in the ethylene / propylene copolymer satisfy the relationship of the following formula (1).
Equation (1): (Y) ≧ -1157 × (X) + 1080
(However, Y is the number per 1000 carbon atoms in total of the main chain and the side chain measured by NMR.)

Further, according to the fifth invention of the present invention, in any one of the first to fourth inventions, the ethylene / propylene copolymer (A) further satisfies the following property (a-6). The polyethylene resin composition (D) is provided.
(A-6) The number of branches (Y) and the density (X) due to the comonomer in the ethylene / propylene copolymer satisfy the relationship of the following formula (2).
Equation (2): (Y) ≧ -1157 × (X) +1084
(However, Y is the number per 1000 carbon atoms in total of the main chain and the side chain measured by NMR.)

Further, according to the sixth invention of the present invention, in any one of the first to fifth inventions, the polyethylene resin composition (D) further has the following properties (d-1) to (d-2). Provided is a polyethylene resin composition (D), which is characterized by filling.
(D-1) MFR (190 ° C., 21.18N load) 1 to 100 g / 10 minutes (d-2) Density 0.88 to 0.94 g / cm ³

Further, according to the seventh invention of the present invention, one of the resin layer (a) containing the polyethylene resin composition (D) according to any one of the first to sixth inventions and the resin layer (a). Provided is a laminate characterized by having at least three layers of a base material layer (b) in contact with a surface and a barrier layer (c) in contact with the other surface of the resin layer (a).

Further, according to the eighth invention of the present invention, in the seventh invention, the base material layer (b) is a base material layer containing polyester resin, polyamide resin or paper as a main component. The body is provided.

Further, according to the ninth invention of the present invention, in the seventh or eighth invention, the barrier layer (c) is a metal foil, a metal vapor-deposited film, a transparent vapor-deposited film, a film containing a barrier resin layer, or a barrier coating. A laminate is provided, characterized in that it is a film containing layers.

Further, according to the tenth invention of the present invention, there is provided a laminate according to any one of the seventh to ninth inventions, wherein the laminate is formed by an extrusion coating method.

The polyethylene resin composition of the present invention is extremely excellent in adhesiveness to a base material layer such as a polyethylene terephthalate resin film and a barrier layer such as a metal foil, and the resin layer and the base material layer containing the polyethylene resin composition The laminate having the barrier layer is a laminate having excellent protection performance of the contents because it exhibits good adhesiveness between the polyethylene resin composition and the base material layer and the barrier layer.

6 is a graph showing PET adhesive strength and Al adhesive strength obtained in Examples and Comparative Examples of the present invention.

The present invention requires a resin layer containing a polyethylene resin composition containing a specific ethylene / propylene copolymer or the like and a base material layer, preferably at least a surface in contact with the resin layer, containing a polyethylene terephthalate resin as a main component. A laminate comprising a base material layer which is a film, more preferably a barrier layer in contact with a surface on the side where the resin layer is not in contact with the base material layer, preferably a metal foil or a metal vapor-deposited film. It is related to.
Hereinafter, each component used in the present invention, a laminate using them, and the like will be described in detail.

1. 1. Polyethylene resin composition (D)
The polyethylene resin composition of the present invention (hereinafter, also simply referred to as a resin composition) is epoxidized vegetable oil (B) 0 with respect to 100 parts by weight of the resin component in the ethylene / propylene copolymer (A) and the resin composition. A resin composition containing up to 0.5 parts by weight, preferably containing low-density polyethylene (C) produced by a high-pressure radical polymerization method.

(1) Ethylene / propylene copolymer (A)
The ethylene-propylene copolymer (A) used in the present invention has the following properties (a-1) to (a-4).
(A-1) Containing 80 to 98 mol% of a constituent unit derived from ethylene as a main component and 2 to 20 mol% of a constituent unit derived from propylene as an essential subcomponent, and forming a third α-olefin other than ethylene and propylene. The derived structural unit may be contained in an amount of 5 mol% or less as a sub-component (however, when the structural unit derived from the third α-olefin is contained, the structural unit derived from ethylene and the structural unit derived from propylene are used. The total of the structural units derived from the third α-olefin does not exceed 100 mol%.)
(A-2) MFR (190 ° C., 21.18 N load) 0.1 to 100 g / 10 minutes (a-3) Density 0.88 to 0.94 g / cm ³
(A-4) The total amount of vinyl and vinylidene in the ethylene / propylene copolymer is 0.35 (pieces / total 1000C) or more (however, the number of vinyl and vinylidene is the number of the main chain and side chains measured by NMR. It is the number per 1000 carbon atoms in total.)

The copolymer containing ethylene and propylene as constituents is obtained by a so-called ethylene propylene rubber (EPM), which is a solution polymerization method containing more than 20 mol% of propylene components and having a density of 0.870 g / cm ³ or less. The rubber-like polymer used is used in the field of elastomers, but the ethylene-propylene copolymer (A) of the present invention has a density range and the amount of ethylene and propylene contained in the ethylene propylene rubber. It is a polymer that is different and has completely different physical properties.
Further, among propylene polymers, propylene ethylene copolymers containing a small amount of ethylene component in the production process are also known, but these are also very different in terms of their propylene content and the like, and their physical properties are also completely different. ..
Further, since an ethylene / α-olefin copolymer (LLDPE) having a so-called ordinary linear molecular structure has been developed mainly for film applications, C4 for obtaining a high-strength copolymer is usually used. C4 or higher α-olefins such as C6 and C6 are usually used as the main comonomer component, and the copolymer is composed of ethylene and propylene using low-strength C3 comonomer as the main sub-component and has a high density. Copolymers of 0.88 g / cm ³ or more have received little attention so far, and at least have not been marketed by the applicant.
Recently, an ethylene / propylene copolymer was newly produced using C3 comonomer as a main subcomponent in such a density region, and various studies were conducted. In particular, new ones (a-1) to (a-4) were found. It has been found that the effect of the present invention can be obtained in a laminate containing a polyethylene resin composition using an ethylene / propylene copolymer having physical properties in various regions.

(I) Characteristics of Ethylene-propylene Copolymer (A) (a-1) Monomer Composition The ethylene-propylene copolymer (A) used in the present invention contains 80 to 98 mol of a structural unit derived from ethylene as a main component. %, An ethylene / propylene copolymer characterized by containing 2 to 20 mol% of a constituent unit derived from propylene as an auxiliary component, and a specific example thereof is a copolymer obtained by polymerization by a catalytic polymerization method. , It is a copolymer formed by polymerizing substantially linearly and randomly. Specifically, it is a random copolymer of ethylene and propylene. Preferably, the ethylene-derived structural unit is 82 to 97 mol%, the propylene-derived structural unit is 3 to 18 mol%, more preferably the ethylene-derived structural unit is 85 to 95 mol%, and the propylene-derived structural unit is 5. ~ 15 mol%. Here, the amount of monomer such as ethylene content is a value calculated by measuring with ¹³ C-NMR under the conditions described in Examples described later.

It should be noted that a configuration that does not contain any other α-olefins, particularly a structural unit derived from an α-olefin having 4 to 20 carbon atoms and other monomer components, is preferable, but a configuration that does not contain such a trace amount may be included. .. In the present specification, α-olefins other than ethylene and propylene are referred to as a third α-olefin. The ethylene-propylene copolymer (A) of the present invention contains, for example, 5 mol% or less, preferably 2 mol% or less, and more preferably 1 with a constituent unit derived from a third α-olefin other than ethylene and propylene as a subcomponent. It may contain .5 mol% or less, more preferably 1 mol% or less, and most preferably 0.5 mol% or less. Here, when the ethylene-propylene copolymer (A) of the present invention contains a structural unit derived from a third α-olefin, a structural unit derived from ethylene, a structural unit derived from propylene, and a third α -The total of constituent units derived from olefins does not exceed 100 mol%. Further, in this case, the content of the structural unit derived from propylene is preferably higher than the content of the structural unit derived from the third α-olefin. When the ethylene / propylene copolymer (A) of the present invention contains a structural unit derived from a third α-olefin, one or more third α-olefins can be used. ..
Further, the ethylene / propylene copolymer (A) is one or two kinds within a range that satisfies (a-1) to (a-4), more preferably (a-5) and (a-6). The above combination may be used.

When propylene is used as an essential comonomer as an auxiliary component and a high-pressure ion polymerization method using a metallocene catalyst described later is adopted, an ethylene / α-olefin copolymer having a large total number of vinyl and vinylidene can be obtained. Is possible. When α-olefins such as 1-hexene and 1-octene are polymerized as a comonomer main component, this effect is difficult to obtain.

(A-2) MFR
The ethylene / propylene copolymer (A) used in the present invention has a melt flow rate (MFR: 190 ° C., 21.18 N load) of 0.1 to 100 g / 10 minutes, preferably 1 to 80 g / 10 minutes. Yes, more preferably 5 to 70 g / 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the ductility during molding is deteriorated and the motor load in the extruder is increased, which is not preferable. On the other hand, if the MFR exceeds 100 g / 10 minutes, the state of the molten film at the time of molding becomes unstable, which is not preferable.
In order to adjust the MFR of the polymer, for example, a method of appropriately adjusting the polymerization temperature, the amount of comonomer, and the like is adopted. The MFR of the ethylene / propylene copolymer is measured in accordance with JIS-K6922-2: 1997 Annex (190 ° C., 21.18 N load).

(A-3) Density The ethylene / propylene copolymer (A) used in the present invention has a density of 0.88 to 0.94 g / cm ³ , preferably 0.885 to 0.94 g / cm ³ . , More preferably 0.89 to 0.93 g / cm ³ . If the density is less than 0.88 g / cm ³ , blocking will be poor, which is not preferable. On the other hand, if the density exceeds 0.94 g / cm ³ , the adhesiveness becomes poor, which is not preferable.
In order to adjust the density of the polymer, for example, a method of appropriately adjusting the comonomer content, the polymerization temperature, the amount of catalyst, etc. is adopted. The density of the ethylene / propylene copolymer is measured in accordance with JIS-K6922-2: 1997 Annex (in the case of low-density polyethylene) (measurement temperature 23 ° C.).

(A-4) Total number of vinyl and vinylidene In a copolymer obtained by copolymerizing one or more kinds of ethylene and α-olefin, the mechanism of the manufacturing process is as follows even if the diene monomer is not actively added. Due to the differences, various double bonds (vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted olefins) may be formed, and the amounts and types thereof may vary.
Conventionally, in order to obtain good cross-linking properties as a solar cell encapsulant, it has been known that the cross-linking properties are good when the number of double bonds contained in the ethylene / α-olefin copolymer is large. In the field of resin compositions for lamination, differences depending on the amount and type of double bonds have not been investigated.
In the present invention, among various double bonds contained in the ethylene / propylene copolymer, it is found that vinyl and vinylidene are particularly important in the adhesive strength, and the total number of vinyl and vinylidene is ordinary ethylene. We have found that the effects of the present invention can be achieved by producing an ethylene / propylene copolymer that is larger than the α-olefin copolymer and using it as an ethylene / propylene copolymer for a resin composition for lamination. It is a thing.

The ethylene / propylene copolymer (A) used in the present invention has a total of 0.35 double bonds of vinyl and vinylidene per 1000 carbon atoms of the main chain and side chains measured by NMR. Total 1000C) or higher, preferably 0.40 to 5.0 (pieces / total 1000C), more preferably 0.45 to 4.5 (pieces / total 1000C), and even more preferably 0.50. ~ 4.0 (pieces / total 1000C).
If the total number of vinyl and vinylidene is in the above range, the resin composition has excellent adhesive strength, and if it is less than 0.35, the adhesive strength is not sufficient. The total number of vinyl and vinylidene can be controlled within the above range by appropriately adjusting the selection of an appropriate metallocene catalyst, the polymerization temperature, the comonomer species, and the amount of comonomer.
The number of these double bonds is the number per 1000 carbon atoms in total of the main chain and the side chain, and is a value calculated by using the integrated intensity of the characteristic peak of ¹ H-NMR spectrum, which will be described later. It is a value measured and calculated under the conditions described in the examples.

Further, in the present invention, the number of vinyls in the ethylene / propylene copolymer (A) preferably satisfies the range of 0.2 (pieces / total 1000C) or more.
Further, in the present invention, the number of vinylidene in the ethylene / propylene copolymer preferably satisfies the range of 0.12 (pieces / total 1000C) or more.

(A-5) Relationship between Number of Branches (Y) and Density (X) by Comonomer The ethylene-propylene copolymer (A) used in the present invention has the following number of branches (Y) and density (X) due to comonomer. It is preferable to satisfy the formula (1).
Equation (1): (Y) ≧ -1157 × (X) + 1080
When the density and the number of branches satisfy the relationship of the above formula (1), the number of branches due to the comonomer is sufficiently secured, and the resin composition has excellent adhesive strength.
Here, the number of branches (Y) by the comonomer is the number (pieces / total 1000C) per 1000 carbon atoms in total of the main chain and the side chain measured by NMR of the ethylene / propylene copolymer (A).
The density (X) is the density of the ethylene / propylene copolymer (A), and is measured as described above.

The number of branches (Y) by the comonomer indicates the amount of tertiary carbon contained in the polymer, and is the number per total of 1000 carbon atoms of the main chain and the side chain measured by NMR. For example, E.I. W. Hansen, R.M. Bloom, and O.D. M. It can be calculated from the ¹³ C-NMR spectrum with reference to Bade, Polymer, Vol. 36, p. 4295 (1997).
The relationship between the density and the number of branches can be adjusted by the polymerization conditions such as the type and ratio of the copolymerizing comonomer and the polymerization temperature.

(A-6) Relationship between Number of Branches (Y) and Density (X) by Comonomer The ethylene-propylene copolymer (A) used in the present invention has the following number of branches (Y) and density (X) due to comonomer. It is more preferable to satisfy the formula (2).
Equation (2): (Y) ≧ -1157 × (X) +1084
When the density and the number of branches satisfy the relationship of the above formula (2), the number of branches due to the comonomer is sufficiently secured, and the resin composition has excellent adhesive strength.
Here, the number of branches (Y) by the comonomer is the number (pieces / total 1000C) per 1000 carbon atoms in total of the main chain and the side chain measured by NMR of the ethylene / propylene copolymer (A).

(Ii) Polymerization catalyst and polymerization method of ethylene / propylene copolymer (A) The catalyst used in the production of the ethylene / propylene copolymer (A) used in the present invention is not particularly limited, but is more preferable. A metallocene catalyst is used.
The metallocene catalyst is not particularly limited, and examples thereof include a catalyst containing a metallocene compound such as a zirconium compound in which a group having a cyclopentadienyl skeleton is coordinated and a co-catalyst as catalyst components. In particular, it is preferable to use a metallocene compound such as a zirconium compound in which a group having a cyclopentadienyl skeleton is coordinated.
The production method is not particularly limited, and a high-pressure ion polymerization method, a gas phase method, a solution method, a slurry method and the like can be used, but the ethylene / propylene copolymer (A) having a double bond adjusted according to the present invention. ), It is desirable to carry out polymerization at a high temperature of 150 to 330 ° C., so it is preferable to use the high-pressure ion polymerization method ("Polyethylene Technology Reader", Chapter 4, edited by Kazuo Matsuura and Naotaka Mikami, 2001. Year).

(2) Epoxy vegetable oil (B)
Epoxidized vegetable oil is an epoxidized unsaturated double bond of natural vegetable oil using peracid or the like. For example, epoxidized soybean oil, epoxidized linseed oil, epoxidized olive oil, epoxidized safflower oil, etc. Epoxide corn oil and the like can be mentioned. These epoxidized vegetable oils are commercially available, for example, manufactured by ADEKA Corporation, O-130P (epoxidized soybean oil), O-180A (epoxidized linseed oil) and the like. The presence of an oil that is not epoxidized or is insufficiently epoxidized, which is slightly by-produced when epoxidizing a vegetable oil, does not hinder the action and effect in the present invention.

By the way, the epoxidized vegetable oil (B) used in the present invention is used as a stabilizer or plasticizer for a polymer such as polyvinyl chloride, or is a resin containing a carboxylic acid group or a carboxylic acid derivative group in the molecule. A technique for adding and using as a cross-linking agent is disclosed (Japanese Patent Laid-Open No. 60-112815). Further, a technique for adding to general-purpose polyethylene is also disclosed (Patent Documents 3 and 4). However, the present inventors blend the epoxidized vegetable oil used in these applications with the specific ethylene-based polymer of the present invention to form a composition, and oxidize it at the time of molding to obtain the substrate layer. It was found that an extremely strong effect of improving adhesiveness was obtained, and this effect was unexpected. The reason for this improvement in adhesiveness is not necessarily clear, but the ethylene-based polymer is air-oxidized in contact with air when it is extruded in an extruder or from a T-die or the like during melt molding of a polyethylene resin composition. A reaction with the epoxidized vegetable oil occurs in the process of oxidation. First, the epoxidized vegetable oil is grafted to the ethylene polymer, and the unreacted epoxy group remaining in the molecule of the grafted epoxidized vegetable oil is on the surface of the substrate layer. It is presumed that it reacts with the functional group of.

The epoxidized vegetable oil (B) used in the present invention has two or more epoxy groups in the molecule from the viewpoint of the above-mentioned effect of improving adhesiveness. Further, the epoxidized vegetable oil (B) preferably has a molecular weight of 3000 or less. More preferably, the molecular weight is 2000 or less and 100 or more.

(3) High-pressure radical polymerization method Low-density polyethylene (C)
High-pressure radical polymerization method used in the present invention The low-density polyethylene (C) (hereinafter, also simply referred to as low-density polyethylene (C)) is a high-pressure radical polymerization method having the following characteristics (c-1) to (c-2). It is the low density polyethylene (LDPE) obtained in the above, preferably a long-chain branched low density polyethylene.
(C-1) MFR (190 ° C., 21.18N load) 0.1 to 20 g / 10 minutes (c-2) Density 0.915 to 0.930 g / cm ³

(I) High-pressure radical polymerization method Characteristics of low-density polyethylene (C) (c-1) MFR
The melt flow rate (MFR: 190 ° C., 21.18 N load) of the low-density polyethylene (C) used in the present invention is 0.1 to 20 g / 10 minutes, preferably 0.5 to 15 g / 10 minutes. , More preferably 1 to 15 g / 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the ductility becomes insufficient and the film breaks during high-speed molding. On the other hand, if the MFR exceeds 20 g / 10 minutes, the molten film becomes unstable.
Here, MFR is a value measured in accordance with JIS-K6922-2: 1997 Annex (190 ° C., 21.18N load).

(C-2) Density The density of the low-density polyethylene (C) used in the present invention is 0.915 to 0.930 g / cm ³ , preferably 0.916 to 0.926 g / cm ³ , more preferably. Is 0.917 to 0.925 g / cm ³ . If the density is less than 0.915 g / cm ³ , stickiness increases. On the other hand, if it exceeds 0.93 g / cm ³ , the adhesiveness becomes poor.
Here, the density is measured in accordance with JIS-K6922-2: 1997 Annex (in the case of low density polyethylene) (measurement temperature 23 ° C.).

(Ii) High-pressure radical polymerization method Polymerization method of low-density polyethylene (C) The low-density polyethylene (C) used in the present invention is generally produced by using a tank-type reactor or a tube-type reactor, and the presence of a radical generator. It is carried out by polymerizing ethylene under the conditions of a polymerization pressure of 1000 to 3000 kg / cm ² and a polymerization temperature of 150 to 300 ° C. The MFR can be regulated by using a hydrocarbon such as hydrogen, methane, or ethane as the molecular weight modifier.

(4) Polyethylene resin composition (D)
The polyethylene resin composition (D) of the present invention includes an ethylene / propylene copolymer (A), optionally the above-mentioned epoxidized vegetable oil (B) and low-density polyethylene (C), and any other resin component described later. It contains an additive described later.
The amount (concentration ratio) of the epoxidized vegetable oil (B) added to the resin composition in the present invention includes the ethylene / propylene copolymer (A), low-density polyethylene (C) blended as needed, and described later. For example, 0 parts by weight to 0.5 parts by weight (0 parts by weight ppm to 5000 parts by weight of the entire resin composition), preferably 0 parts by weight, based on 100 parts by weight of the total resin component totaling the amounts of other resin components. Parts to 0.3 parts by weight (0 parts by weight ppm to 3000 parts by weight based on the entire resin composition), more preferably 0 parts by weight to 0.2 parts by weight (0 parts by weight ppm to 2000 parts by weight based on the entire resin composition). ppm). If the content of the epoxidized vegetable oil (B) with respect to 100 parts by weight of the total resin component exceeds 0.5 parts by weight, problems such as blocking due to stickiness and odor may occur, which is not preferable.
In the present invention, the content (ratio) of the epoxidized vegetable oil (B) in 100 parts by weight of the polyethylene resin composition (D) is general when used in combination with the specific ethylene / propylene copolymer (A). One of the features is that it has high adhesiveness even when it is much less than the case where only low-density polyethylene and an epoxy compound are used in combination. In that case, the content (ratio) of the epoxidized vegetable oil (B) is preferably 0.3 parts by weight (3000 parts by weight ppm based on the entire resin composition), more preferably, in 100 parts by weight of the total resin components. 0.2 parts by weight (2000 ppm by weight based on the entire resin composition), more preferably 0.13 parts by weight (1300 ppm by weight based on the entire resin composition), still more preferably 0.1 parts by weight (1300 weight ppm based on the entire resin composition). 1000 wt ppm or less with respect to the entire resin composition, most preferably 0.08 parts by weight (800 wt ppm with respect to the entire resin composition) or less, even when the content (ratio) is extremely small. One of the features is that it has very high adhesiveness.

The content ratio of the ethylene / propylene copolymer (A) in the polyethylene resin composition (D) of the present invention is, for example, 10% by weight to 99.999% by weight, preferably 10% by weight to 99.99% by weight. It is preferably 20% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, and particularly preferably 70% by weight or more.

Further, when the polyethylene resin composition (D) of the present invention contains low density polyethylene (C) as a resin component in addition to the ethylene / propylene copolymer (A), the ethylene / propylene copolymer (A) The content ratio of (A): (C) to the high-pressure radical polymerization method low-density polyethylene (C) is, for example, 5 to 95% by weight: 5 to 95% by weight, preferably 10 to 95% by weight: 5. It is ~ 90% by weight, more preferably 20 to 95% by weight: 5 to 80% by weight, still more preferably 30 to 95% by weight: 5 to 70% by weight. Even more preferably, it is 40 to 95% by weight: 5 to 60% by weight. If the amount of the ethylene / propylene copolymer (A) is too large, the stability of the molten film tends to decrease, and if the amount of the high-pressure radical polymerization method low-density polyethylene (C) is large, the adhesive strength may decrease.
In particular, when the ratio (A: C) of the ethylene / propylene copolymer (A) to the high-pressure radical polymerization method low-density polyethylene (C) is 50 to 95% by weight: 5 to 50% by weight, the adhesive strength becomes higher. Is high, which is preferable.

(I) Characteristics of polyethylene resin composition (D) (d-1) MFR
The melt flow rate (MFR: 190 ° C., 21.18 N load) of the polyethylene resin composition (D) used in the present invention is 1 to 100 g / 10 minutes, preferably 1 to 80 g / 10 minutes, and more. It is preferably 2 to 70 g / 10 minutes. If the MFR is less than 1 g / 10 minutes, the ductility during molding is deteriorated and the motor load in the extruder is increased, which is not preferable. On the other hand, if the MFR exceeds 100 g / 10 minutes, the state of the molten film at the time of molding becomes unstable, which is not preferable.
Here, MFR is a value measured in accordance with JIS-K6922-2: 1997 Annex (190 ° C., 21.18N load).

(D-2) Density The density of the polyethylene resin composition (D) used in the present invention is 0.88 to 0.94 g / cm ³ , preferably 0.885 to 0.94 g / cm ³ , and more. It is preferably 0.89 to 0.935 g / cm ³ . If the density is less than 0.88 g / cm ³ , blocking will be poor, which is not preferable. On the other hand, if the density exceeds 0.94 g / cm ³ , the adhesiveness becomes poor, which is not preferable.
Here, the density is measured in accordance with JIS-K6922-2: 1997 Annex (in the case of low density polyethylene) (measurement temperature 23 ° C.).

(5) Other components The polyethylene resin composition (D) used in the present invention or the resin layer (a) containing the polyethylene resin composition (D) may be, if necessary, phenol-based, phosphorus-based, etc., which are usually used for polyethylene-based resins. Antioxidants, stabilizers such as metal soaps, antiblocking agents, lubricants, dispersants, pigments such as organic or inorganic colorants, antifogging agents such as unsaturated fatty acid esters, antistatic agents, ultraviolet absorbers, Additives such as a light stabilizer and a nucleating agent may be added. For example, a preferable blending range of the antioxidant is, in terms of weight ratio, 5000 ppm or less, more preferably 3000 ppm or less, and further preferably 1000 ppm or less.
Further, LDPE, LLDPE (C4-LLDPE, HAO-LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid common weight, as long as the characteristics of the polyethylene resin composition (D) of the present invention are not impaired. Coalescence (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid ester copolymer (EEA, EMA, EMMA, etc.), polyethylene resin such as high density polyethylene (HDPE), ethylene-maleine anhydride Adhesive resins such as acid copolymers, polypropylene resins, polystyrene resins and other thermoplastic resins may be blended.
Moreover, it is preferable that the polyethylene resin composition (D) of the present invention does not contain a cross-linking agent.

2. 2. Base material layer (b)
Examples of the base material layer (b) used in the present invention include a single-layer film such as polyamide, polyester, polypropylene, polyethylene, ethylene / vinyl alcohol copolymer, or a laminated film made of the same or different materials thereof. The film is preferably a stretched film. Further, a laminated base material such as paper such as kraft paper can be mentioned.
A base material other than the polyethylene resin, particularly preferably a base material layer mainly composed of a polyamide resin or a polyester resin which is a resin material having a functional group (b), or a base material layer mainly composed of paper. In the case of (b), the excellent adhesiveness of the present invention can be utilized. Here, the amount of the polyamide resin, polyester resin or paper contained in the base material layer (b) is, for example, 50% by weight to 100% by weight.
A particularly preferable base material layer (b) used in the present invention is a film in which at least the surface in contact with the resin layer (a) containing the polyethylene resin composition (D) of the present invention requires polyethylene terephthalate resin as a main component. Examples thereof include a single-layer film of polyethylene terephthalate and a laminated film made of the same or different materials as polyethylene terephthalate. The film is preferably a stretched film. The amount of the polyethylene terephthalate resin contained in the base material layer (b) is, for example, 50% by weight to 100% by weight. When the base material layer (b) contains a resin other than the polyethylene terephthalate resin, the resin mentioned as an example of the other base material layer described later can be used.
The base material layer may be printed, vapor-deposited, various coatings, or the like.

3. 3. Barrier layer (c)
The barrier layer (c) used in the present invention includes a single-layer barrier layer such as a metal foil such as aluminum or copper, a plastic film on which a metal or an inorganic substance or an organic substance is deposited, or a plastic film having a barrier coating. The laminated barrier layer of.
When the barrier layer (c) is preferably a metal foil, a metal vapor-deposited film, a transparent vapor-deposited film, a film containing a barrier resin layer, or a film containing a barrier coating layer, a metal foil or a metal-deposited film is more preferable. When the barrier layer (c) is used, the excellent adhesiveness of the present invention can be utilized. The metal foil or metal vapor deposition film in the present invention is a metal foil such as aluminum, gold, silver, iron, steel, copper, nickel, and alloys containing these as main components; aluminum, on the surface of a film such as polyester or polyamide. It is a vapor-deposited film on which a metal such as silicon is vapor-deposited. Further, the transparent vapor deposition film includes, for example, a plastic film in which a transparent vapor deposition layer is formed by metal oxide vapor deposition such as aluminum oxide vapor deposition and silicon oxide vapor deposition. Examples of the film containing the barrier resin layer include a film containing a layer of an allyl alcohol copolymer.

4. Laminated body The laminated body of the present invention has at least two layers of a resin layer (a) containing the polyethylene resin composition (D) described above and a base material layer (b) in contact with one surface of the resin layer (a). , Preferably, a laminate having at least a total of three layers [base material layer (b) / resin layer (a) / barrier layer (c)] of the barrier layer (c) in contact with the other surface of the resin layer (a). Is. A resin layer (a) containing the polyethylene resin composition (D) is directly adhered to at least one surface of the base material layer (b). It is more preferable that the resin layer (a) is in direct contact with the barrier layer (c) on the surface on the side that is not in contact with the base material layer (b).
There are no restrictions on the configuration of the laminate, but for example, a laminate including the following configuration is exemplified.
Includes base material layer (b) / resin layer (a) containing resin composition (D), resin layer (a) containing resin composition (D) / base material layer (b) / resin composition (D) Resin containing resin layer (a), base material layer (b) / resin composition (D) / resin layer (a) / base material layer (b), base material layer (b) / resin containing resin composition (D) Layer (a) / barrier layer (c), resin layer (a) containing the resin composition (D) / base material layer (b) / resin layer (a) containing the resin composition (D) / base material layer ( B), resin layer (a) containing the resin composition (D) / base material layer (b) / resin layer (a) containing the resin composition (D) / barrier layer (c), base material layer (b) / Resin layer (a) containing the resin composition (D) / Base material layer (b) / Resin layer (a) containing the resin composition (D) / Base material layer (b), Base material layer (b) / Resin layer (a) containing the resin composition (D) / barrier layer (c) / resin layer (a) containing the resin composition (D) / base material layer (b), base material layer (b) / resin composition Resin layer (a) containing the substance (D) / base material layer (b) / resin layer (a) containing the resin composition (D) / barrier layer (c), base material layer (b) / resin composition ( Resin layer (a) containing (D) / other base material layer, other resin layer / base material layer (b) / resin layer (a) containing resin composition (D), other resin layer / base material layer (b) / Resin layer (a) containing the resin composition (D) / barrier layer (c), other base material layer / base material layer (b) / resin layer (a) containing the resin composition (D), other base material Layer / base material layer (b) / resin layer (a) containing resin composition (D) / barrier layer (c), base material layer (b) / resin layer containing resin composition (D) / Other resin layer, base material layer (b) / resin layer (a) containing resin composition (D) / barrier layer (c) / other resin layer Here, the other base material layer is the base material layer (b). And a base material layer different from the barrier layer (c), for example, a plastic film or sheet such as polypropylene resin, polyamide resin, polyester resin, ethylene-vinyl acetate copolymer saponified product, polyvinylidene chloride, polycarbonate, etc. , Stretched product of the above film or sheet, printed matter, secondary processed film or sheet such as vapor deposition of metal, etc., metal foil or metal plate such as aluminum, iron, copper, alloy containing these as main components, cellophane, paper , Woven cloth, non-woven fabric and the like.
Examples of the other resin layer include LDPE, LLDPE (C4-LLDPE, HAO-LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid. Polyethylene resins such as copolymers (EMAA), ethylene-acrylic acid ester copolymers (EEA, EMA, EMMA, etc.), high density polyethylene (HDPE), adhesive resins such as ethylene-maleic anhydride copolymer, Examples thereof include other thermoplastic resins such as polypropylene resin and polystyrene resin.

The method for producing the laminate is not particularly limited, but for example, a so-called extrusion coating method in which the polyethylene resin composition is melt-extruded and laminated on the base material layer is preferable. Further, it is preferable that the extruded coating is laminated one or more layers by a method such as a single layer, a sandwich laminate, a coextrusion laminate, or a tandem laminate. The resin layer (a) containing the polyethylene resin composition (D) can be used not only as an adhesive layer but also as a surface sealant. According to the present invention, since the adhesion to the substrate is good, high-speed molding becomes possible.

Further, the method for ensuring the adhesiveness with the base material layer is not particularly limited, but for example, the surface treatment of the base material may be performed. Examples of the surface treatment method include various treatment methods such as corona discharge treatment method, ozone treatment method, frame treatment method, and low temperature plasma treatment method. Another method is to spray ozone on the molten resin. When another base material layer is provided, it is preferable to perform an anchor coating treatment as needed.

The laminate of the present invention is formed of the resin layer (a) containing the above polyethylene resin composition (D), has excellent adhesive strength with the base material layer (b) and the barrier layer (c), and protects the contents. It is a laminated body with excellent performance.

The laminate of the present invention has adhesiveness to the base material layer (b) and the barrier layer (c), particularly a base material layer (b) having a polyethylene terephthalate film or the like on the surface and a barrier layer having a metal such as aluminum on the surface. Both have good adhesiveness to (c). Therefore, it can be suitably used as a clean packaging film, packaging body, etc. for foods, medical treatments, electronic materials, etc.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The evaluation methods and resins used in Examples and Comparative Examples are as follows.

1. 1. Evaluation method of resin physical properties (1) Melt flow rate (MFR)
As described above, the MFR of the ethylene / propylene copolymer, high-pressure radical polymerization method low-density polyethylene or polyethylene resin composition is measured in accordance with JIS-K6922-2: 1997 Annex (190 ° C., 21.18 N load). did.
(2) Density As described above, the density of the ethylene / propylene copolymer, high-pressure radical polymerization method low-density polyethylene or polyethylene resin composition is JIS-K6922-2: 1997 Annex (23 ° C, in the case of low-density polyethylene). Measured according to.

(3) Amount of comonomer, number of branches due to comonomer and number of double bonds The amount of comonomer and number of branches due to comonomer (Y) are determined by ¹³ C-NMR, and the number of double bonds (vinyl, vinylidene) is determined by ¹ H-NMR. It was measured under the following conditions, and was determined by the total number of main and side chains per 1000 carbons.
Equipment: Bruker Biospin Co., Ltd. AVANCE III cryo-400MHz
Solvent: o-dichlorobenzene / layered bromobenzene = 8/2 mixed solution <sample amount>
460mg / 2.3ml
< ¹³ C-NMR>
· ¹ H decoupling, NOE Ali cumulative number of times: 256scan
・ Flip angle: 90 °
-Pulse interval 20 seconds-AQ (capture time) = 5.45s D1 (waiting time) = 14.55s
< ^{1 1} H-NMR>
・ Number of integrations: 1400scan
・ Flip angle: 1.03 °
・ AQ (capture time) = 1.8s D1 (waiting time) = 0.01s

(4) Melt film stability The stability of the molten film was visually observed at an extruder of 90 mmφ, a T-die 560 mm width, a lip width of 0.8 mm, an air gap of 120 mm, a molding temperature of 325 ° C., and a take-up speed of 100 m / min. The case where the molten film is stable and can be processed is evaluated as “◯”, and the case where the molten film is unstable and cannot be processed to a uniform thickness is evaluated as “x”.

(5) Adhesive strength (5-1) Base material layer (b)
Using the laminator of a 90 mmφ extruder, the base material layer (b) is fed out from the feeder to be used as the base material, and the surface to be in contact with the resin layer (a) is subjected to corona treatment 20 W · min / m ² from the sand side. A linear low-density polyethylene (LLDPE) film (LL-XMTN manufactured by Futamura Chemical Co., Ltd.) having a thickness of 30 μm is fed out, and the polyethylene resin composition (D) is extruded and sand-laminated under the conditions of a take-up speed of 100 m / min and a thickness of 15 μm. Carried out. A laminate of a base material layer (b), a resin layer (a), and an LLDPE layer of 30 μm was obtained.
The obtained laminate was cut into strips having a width of 15 mm in the flow direction and peeled at the interface between the resin layer (a) and the base material layer (b), and the number of subjects was 5, the peeling speed was 300 mm / min, and the peeling speed was 300 mm / min. The peel strength in the T peel test was defined as the adhesive strength. When this layer was cut while pulling the resin layer (a) against the base material layer (b) and peeling it off, the value of the highest point on the chart was used as the adhesive strength.
(5-2) Barrier layer (c)
Using the laminator of a 90 mmφ extruder, the base material layer (b) is fed out from the feeder to be used as the base material, and the surface to be in contact with the resin layer (a) is subjected to corona treatment 20 W · min / m ² from the sand side. The barrier layer (c) was fed out, and the polyethylene resin composition (D) was extruded and sand-laminated under the conditions of a take-up speed of 100 m / min and a thickness of 15 μm. Anchor coating treatment was performed on the opposite surface of the barrier layer (c) on the resin layer (a) side, and Novatec LC600A manufactured by Japan Polyethylene Corporation was extruded and laminated at a take-up speed of 100 m / min and a thickness of 20 μm. B), a resin layer (a), a barrier layer (c), and an LC600A layer were obtained. As the anchor coating agent, a mixture of Takelac A3210 manufactured by Mitsui Chemicals, Takenate A3075 manufactured by Mitsui Chemicals, and NC401 Solvent C manufactured by Toyo Ink Co., Ltd. at a ratio of 3: 1: 28 was used.
The obtained laminate was cut into strips having a width of 15 mm in the flow direction and peeled at the interface between the resin layer (a) and the barrier layer (c), and the number of subjects was 5, the peeling speed was 50 mm / min, and T. The peel strength in the peel test was defined as the adhesive strength. When the resin layer (a) was pulled against the barrier layer (c) and peeled off, and this layer was broken, the value of the highest point on the chart was used as the adhesive strength.

2. 2. Material (1) Base material layer (b)
Toyobo ester film E5102 (thickness 25 μm) manufactured by Toyobo Co., Ltd. was used as a film whose main component is polyethylene terephthalate resin, at least on the surface in contact with the resin layer (a).

(2) Barrier layer (c)
An aluminum foil (thickness 7 μm) manufactured by Toyo Aluminum K.K. was used as the base material of the metal foil whose surface in contact with at least the resin layer (a) was a metal foil.

(3) Ethylene / propylene copolymer (A)
(PE-1) obtained by the following production method was used as the ethylene / propylene copolymer (A). The physical property values are shown in Table 1.

<Manufacturing method of (PE-1)>
(I) Preparation of catalyst To 0.05 mol of the complex "rac-dimethylsilylene bisindenylhafnium dimethyl" prepared by the method described in JP-A No. 10-218921, equal mol of "N, N-dimethylanilinium tetrakis". (Pentafluorophenyl) borate ”was added and diluted with toluene to 50 L to prepare a catalytic solution.

(Ii) Polymerization method Using a stirring autoclave type continuous reactor with an internal volume of 5.0 L, the pressure inside the reactor is maintained at 80 MPa, and ethylene, propylene, and 1-hexene are appropriately adjusted at a rate of 55 kg / hour. The raw material gas was continuously supplied. Further, the ethylene / propylene of (PE-1) is prepared by continuously supplying the catalyst solution described in the above section "(i) Preparation of catalyst" and appropriately adjusting the polymerization temperature within the range of 200 to 250 ° C. A copolymer was obtained.

(4) High-pressure radical polymerization method Low-density polyethylene (C)
High-pressure radical polymerization method low-density polyethylenes (PE-2) to (PE-3) having the physical property values shown in Table 1 were used.

(5) Epoxy vegetable oil (B)
An epoxidized soybean oil ADEKA Sizer O-130P (molecular weight 1000, having two or more epoxy groups in the molecule) manufactured by ADEKA was used.

(6) Antioxidant As a phenolic antioxidant, Irganox 1076 manufactured by BASF was used, and as a phosphoric acid-based antioxidant, Irgafos 168 manufactured by BASF was mixed at a ratio of 1: 1.

(Example 1)
78% by weight of ethylene / propylene copolymer (PE-1) and 22% by weight of high-pressure radical polymerization low-density polyethylene (PE-2) were blended. This was thoroughly mixed, and pellets of the polyethylene resin composition (D) were obtained using a 40 mmφ single-screw extruder.
Using the pellets obtained above, for evaluating the above-mentioned (4) melt film stability, (5-1) adhesive strength base material layer (b), and (5-2) adhesive strength barrier layer (c). Laminates were obtained and evaluated using specific substrate layers, barrier layers and extrusion laminating methods. The evaluation results of the laminated body are shown in Table 1 and FIG.

(Example 2)
A laminate was produced in the same manner as in Example 1 except that 300 ppm by weight of epoxidized vegetable oil was added in Example 1. The evaluation results are shown in Table 1 and FIG.

(Example 3)
A laminate was produced in the same manner as in Example 1 except that 340 ppm by weight of an antioxidant was added in Example 1. The evaluation results are shown in Table 1 and FIG.

(Example 4)
A laminate was produced in the same manner as in Example 1 except that 510 ppm by weight of an antioxidant was added in Example 1. The evaluation results are shown in Table 1 and FIG.

(Comparative Example 1)
In Example 1, the laminate was prepared in the same manner as in Example 1 except that the ethylene-propylene copolymer (A) was not used and the high-pressure radical polymerization method low-density polyethylene (C) (PE-3) was used. Manufactured. The evaluation results are shown in Table 1 and FIG.

(Evaluation)
As is clear from the results of Table 1 and FIG. 1, the laminate according to the embodiment of the present invention is a laminate having excellent adhesive strength with a polyethylene terephthalate resin film, a metal foil, and the like.
On the other hand, when only the high-pressure radical polymerization method low-density polyethylene was used (Comparative Example 1), the adhesive strength was reduced.

The laminate provided with the resin layer containing the polyethylene resin composition of the present invention, the base material layer, and the barrier layer can be used as a clean packaging film, packaging body, etc. for food, medical, electronic materials, and the like.

Claims (10)

A resin composition for forming a resin layer (a) existing between a base material layer (b) and a barrier layer (c), and having the following characteristics (a-1) to (a-4). The polyethylene resin composition (D) containing the ethylene / propylene copolymer (A), and the epoxidized vegetable oil (B) 0 to 0, based on 100 parts by weight of the resin component in the polyethylene resin composition. A polyethylene resin composition (D) containing 5 parts by weight.
(A-1) Containing 80 to 98 mol% of a constituent unit derived from ethylene as a main component and 2 to 20 mol% of a constituent unit derived from propylene as an essential subcomponent, and forming a third α-olefin other than ethylene and propylene. The derived structural unit may be contained in an amount of 5 mol% or less as a sub-component (however, when the structural unit derived from the third α-olefin is contained, the structural unit derived from ethylene and the structural unit derived from propylene are used. The total of the structural units derived from the third α-olefin does not exceed 100 mol%.)
(A-2) MFR (190 ° C., 21.18 N load) 0.1 to 100 g / 10 minutes (a-3) Density 0.88 to 0.94 g / cm ³
(A-4) The total amount of vinyl and vinylidene in the ethylene / propylene copolymer is 0.35 (pieces / total 1000C) or more (however, the number of vinyl and vinylidene is the number of the main chain and side chains measured by NMR. It is the number per 1000 carbon atoms in total.) The first aspect of the present invention, wherein the polyethylene resin composition (D) contains a high-pressure radical polymerization method low-density polyethylene (C) having the following characteristics (c-1) to (c-2). Polyethylene resin composition (D).
(C-1) MFR (190 ° C., 21.18N load) 0.1 to 20 g / 10 minutes (c-2) Density 0.915 to 0.930 g / cm ³ The content ratio (weight ratio A: C) of the ethylene-propylene copolymer (A) and the high-pressure radical polymerization method low-density polyethylene (C) in the polyethylene resin composition (D) is 95 to 5: 5 to 5. The polyethylene resin composition (D) according to claim 2, wherein the composition is 95. The polyethylene resin composition (D) according to any one of claims 1 to 3, wherein the ethylene / propylene copolymer (A) further satisfies the following property (a-5).
(A-5) The number of branches (Y) and the density (X) due to the comonomer in the ethylene / propylene copolymer satisfy the relationship of the following formula (1).
Equation (1): (Y) ≧ -1157 × (X) + 1080
(However, Y is the number per 1000 carbon atoms in total of the main chain and the side chain measured by NMR.) The polyethylene resin composition (D) according to any one of claims 1 to 4, wherein the ethylene / propylene copolymer (A) further satisfies the following property (a-6).
(A-6) The number of branches (Y) and the density (X) due to the comonomer in the ethylene / propylene copolymer satisfy the relationship of the following formula (2).
Equation (2): (Y) ≧ -1157 × (X) +1084
(However, Y is the number per 1000 carbon atoms in total of the main chain and the side chain measured by NMR.) The polyethylene resin composition according to any one of claims 1 to 5, wherein the polyethylene resin composition (D) further satisfies the following properties (d-1) to (d-2). D).
(D-1) MFR (190 ° C., 21.18N load) 1 to 100 g / 10 minutes (d-2) Density 0.88 to 0.94 g / cm ³ A resin layer (a) containing the polyethylene resin composition (D) according to any one of claims 1 to 6, a base material layer (b) in contact with one surface of the resin layer (a), and a resin layer (a). ), The laminate having at least three layers of a barrier layer (c) in contact with the other surface. The laminate according to claim 7, wherein the base material layer (b) is a base material layer containing polyester resin, polyamide resin, or paper as a main component. The laminate according to claims 7 to 8, wherein the barrier layer (c) is a metal foil, a metal vapor-deposited film, a transparent vapor-deposited film, a film containing a barrier resin layer, or a film containing a barrier coating layer. .. The laminate according to any one of claims 7 to 9, wherein the laminate is formed by an extrusion coating method.

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