JP7293789B2 - laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminate, and more specifically, a resin layer containing a polyethylene resin composition composed of an ethylene/propylene copolymer or the like and at least a surface in contact with the resin layer is a base material in which polyethylene terephthalate resin is essential as a main component. It relates to a laminate comprising layers.

Conventional packaging base materials include polyamide resin, which has excellent transparency and mechanical strength, polyethylene terephthalate resin, which has elasticity so that pitch deviation does not occur even when tension is applied during printing, and polypropylene resin, which has excellent moisture resistance. is used. However, the heat-sealing temperature is high, and the packaging speed cannot be increased. The film shrinks during heat-sealing, which deteriorates the package appearance. Therefore, these substrates are rarely used alone, and composite films provided with a heat seal layer are usually used. As the heat seal layer, a layer using a polyethylene resin such as high-pressure low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), linear low-density polyethylene (LLDPE), etc. is widely used. .

As a method for adhering the polyethylene-based resin layer and the substrate, a dry lamination method, an extrusion lamination method, or the like is appropriately selected. In the dry lamination method, an isocyanate-based adhesive is dissolved in an organic solvent to form a solution, which is then applied to one substrate, and after the solvent has evaporated in a dryer, the other substrate is laminated using nip rolls. match. Also in the extrusion lamination method, it is common to coat an adhesive such as an isocyanate-based or urethane-based anchor coating agent on the barrier film in advance, and melt-extrude the polyethylene resin onto the coated surface. is. In particular, polyethylene terephthalate resin substrates are excellent in heat resistance, chemical resistance, insulation, etc., so they are used in a wide range of fields such as packaging films, magnetic tape films, optical films, and electronic component films. .
When an adhesive is used, although the adhesive strength between the layers of the laminate is maintained, the use of a large amount of adhesive increases manufacturing costs, and the use of organic solvents reduces safety and environmental concerns. problems, such as the problem of residual odors in the final product. On the other hand, when an adhesive is not used, the adhesive strength between the layers of the laminate becomes weak, so that the package made of this laminate is easily damaged, and the quality as a packaging material is unstable.

In order to solve these problems, a method using a water-soluble adhesive instead of using a solvent-based adhesive has been proposed. In addition, as a method that does not use an adhesive, a method of introducing a polar group such as an acid anhydride group or a carboxyl group into a polyolefin (see Patent Documents 1 and 2), and a method of using a polyolefin resin composition containing an epoxy compound (Patent References 3 and 4) and a method using polyethylene exhibiting specific physical properties (see Patent Reference 5) have been proposed.
However, when a water-soluble adhesive is used, the adhesive itself is generally water-soluble, so the water resistance is poor. Further, the methods disclosed in Patent Documents 1, 2, and 5 show an improvement in adhesive strength, but are insufficient compared to the method using an adhesive. Furthermore, in the methods disclosed in Patent Documents 3 and 4, it is necessary to add an additive.

JP-A-57-157724 JP-A-59-75915 JP-A-2000-37831 JP 2016-22613 A Japanese Patent Application Laid-Open No. 2002-19060

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a laminate having excellent adhesiveness to a polyethylene terephthalate resin substrate without using an adhesive.

As a result of intensive studies aimed at solving the above problems, the present inventor newly produced experimental ethylene/propylene copolymers having physical properties in the new areas of (c-1) to (c-4) shown below, An ethylene/propylene copolymer having such specific properties, that is, containing a predetermined amount of a main component that is ethylene and a secondary component that is propylene, and having density and MFR within a certain range, and two components contained in the copolymer A polyethylene resin composition containing an ethylene-propylene copolymer having a large amount of heavy bonds and a large number of branches, and preferably further containing a specific high-pressure radical polymerization low-density polyethylene, is used to form a polymer on the polyethylene terephthalate base layer. The inventors have found that a laminate in which a resin layer is directly formed on the inner layer has excellent adhesiveness and is excellent in protecting the contents, and have completed the present invention.

That is, according to the first aspect of the present invention, it has at least two layers, the resin layer (A) and the substrate layer (B),
The resin layer (A) is formed by directly laminating on the substrate layer (B), and the resin layer (A) and the substrate layer (B) each satisfy the following characteristics: A laminate is provided.
Resin layer (A): contains a polyethylene resin composition (E) containing an ethylene/propylene copolymer (C) having the following properties (c-1) to (c-4): (c-1) ethylene 80 to 98 mol% of structural units derived from propylene as main components, 2 to 20 mol% of structural units derived from propylene as essential subcomponents, and structural units derived from a third α-olefin other than ethylene and propylene as subcomponents may contain 5 mol% or less (however, if it contains structural units derived from the third α-olefin, structural units derived from ethylene and structural units derived from propylene and the third α-olefin The sum of derived structural units does not exceed 100 mol%)
(c-2) MFR (190°C, 21.18N load) is 0.1 to 100 g/10 minutes (c-3) Density is 0.88 to 0.94 g/cm ³
(c-4) The total amount of vinyl and vinylidene in the ethylene/propylene copolymer is 0.35 (number/total 1000C) or more (however, the number of vinyl and vinylidene is the number of main chain and side chain measured by NMR) It is the number per 1000 total carbon numbers.)
Base layer (B): A film containing polyethylene terephthalate resin as a main component at least on the surface in contact with the resin layer (A)

Further, according to the second aspect of the present invention, in the first aspect, the polyethylene resin composition (E) has the following characteristics (d-1) to (d-2). A laminate is provided, characterized in that it contains density polyethylene (D).
(d-1) MFR (190°C, 21.18N load) is 0.1 to 20 g/10 minutes (d-2) Density is 0.915 to 0.930 g/cm ³

According to a third aspect of the present invention, in the second aspect, the polyethylene resin composition (E) comprises 95 to 10% by weight of an ethylene/propylene copolymer (C) and a high-pressure radical polymerization low-density A laminate is provided, characterized in that it contains from 5 to 90% by weight of polyethylene (D).

According to a fourth invention of the present invention, in any one of the first to third inventions, the ethylene/propylene copolymer (C) further satisfies the following property (c-5). A laminate is provided.
(c-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).
Formula (1): (Y)≧−1157×(X)+1080
(However, Y is the number per 1000 total carbon atoms of the main chain and side chains measured by NMR.)

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the ethylene/propylene copolymer (C) further satisfies the following property (c-6). A laminate is provided.
(c-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).
Formula (2): (Y)≧−1157×(X)+1084
(However, Y is the number per 1000 total carbon atoms of the main chain and side chains 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 (E) further has the following properties (e-1) to (e-2). A laminate is provided characterized by filling.
(e-1) MFR is 1 to 100 g/10 minutes (e-2) Density is 0.88 to 0.94 g/cm ³

According to a seventh invention of the present invention, there is provided a laminate according to any one of the first to sixth inventions, characterized in that the laminate is formed by an extrusion coating method.

The laminate of the present invention exhibits good adhesiveness between the polyethylene resin composition and the polyethylene terephthalate resin film, and is a laminate excellent in protecting the contents.

The present invention comprises a resin layer containing a polyethylene resin composition containing a specific ethylene/propylene copolymer and preferably a specific high-pressure radical polymerization low-density polyethylene, and at least the surface in contact with the resin layer is mainly composed of polyethylene terephthalate resin. The present invention relates to a laminate characterized by comprising a substrate layer which is a film as an essential component.
Hereinafter, each component used in the present invention, a laminate using them, and the like will be described in detail.

1. Polyethylene resin composition (E)
The polyethylene resin composition (hereinafter also simply referred to as the resin composition) of the present invention is characterized by containing an ethylene/propylene copolymer (C), and further containing a high-pressure radical polymerization low-density polyethylene (D). and more preferably 95 to 10% by weight of ethylene/propylene copolymer (C) and 5 to 90% by weight of high-pressure radical polymerization low-density polyethylene (D).

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

The copolymer having ethylene and propylene as constituent components is so-called ethylene propylene rubber (EPM), which contains more than 20 mol% of propylene component and has a density of 0.870 g/cm ³ or less obtained by a solution polymerization method. The ethylene-propylene copolymer (C) of the present invention differs from these ethylene-propylene rubbers in terms of density range and amount of ethylene or propylene contained. They are different polymers with completely different physical properties.
Among propylene polymers, propylene-ethylene copolymers containing a small amount of ethylene component during the production process are also known. It is a polymer with completely different physical properties.
In addition, since ethylene/α-olefin copolymers (for example, LLDPE) having a so-called normal linear molecular structure have been developed mainly for film applications, they are usually used to obtain high-strength copolymers. It is usual to use C4 or higher α-olefins such as C4 and C6 as the main comonomer component, and it is a copolymer composed of ethylene and propylene using C3 comonomer, which has low strength, as the main subcomponent, and has a density Copolymers having a is of 0.88 g/cm ³ or more have received little attention so far, and at least they have not been commercially available from the present applicant.
Recently, we have newly produced a prototype ethylene-propylene copolymer using a C3 comonomer in such a density range as a main subcomponent, and have conducted various studies. 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 the range.

(i) Characteristics of ethylene/propylene copolymer (C) (c-1) Monomer structure The ethylene/propylene copolymer (C) used in the present invention contains 80 to 98 mol of ethylene-derived structural units as a main component. %, and 2 to 20 mol % of structural units derived from propylene as subcomponents. , is a copolymer obtained by randomly polymerizing a substantially linear chain. A specific example is a random copolymer of ethylene and propylene. Preferably, 82 to 97 mol% of structural units derived from ethylene and 3 to 18 mol% of structural units derived from propylene, more preferably 85 to 95 mol% of structural units derived from ethylene and 5 structural units derived from propylene. ~15 mol%. Here, the amount of monomers such as ethylene content is a value calculated by measuring by ¹³ C-NMR under the conditions described in Examples described later.

In addition, it is preferable to have a configuration that does not contain any structural units derived from other α-olefins, particularly α-olefins having 4 to 20 carbon atoms, and other monomer components, but it may contain such a configuration in a substantially trace amount. . As used herein, α-olefins other than ethylene and propylene are referred to as tertiary α-olefins. The ethylene/propylene copolymer (C) of the present invention contains, for example, 5 mol % or less, preferably 2 mol % or less, more preferably 1.1. 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 (C) of the present invention contains a structural unit derived from a third α-olefin, the structural unit derived from ethylene, the structural unit derived from propylene, and the third α - The total amount of structural units derived from olefins does not exceed 100 mol%. In this case, the content of structural units derived from propylene is preferably higher than the content of structural units derived from the third α-olefin. Further, when the ethylene/propylene copolymer (C) of the present invention contains structural units derived from a third α-olefin, one or more of the third α-olefins can be used. .
In addition, the ethylene/propylene copolymer (C) is one or two in the range satisfying (c-1) to (c-4), more preferably (c-5) and (c-6). A combination of the above may also be used.

Propylene is used as an essential comonomer as a secondary component, and in particular, when a high-pressure ion polymerization method using a metallocene catalyst, which will be described later, is employed, an ethylene/α-olefin copolymer having a uniquely large total number of vinyl and vinylidene can be obtained. becomes possible. This effect is difficult to obtain when an α-olefin such as 1-hexene or 1-octene is used as the main comonomer for polymerization.

(c-2) MFR
The ethylene/propylene copolymer (C) used in the present invention has a melt flow rate (MFR: 190° C., 21.18 N load) of 0.1 to 100 g/10 min, preferably 1 to 80 g/10 min. Yes, more preferably more than 5 g/10 minutes and 70 g/10 minutes or less. If the MFR is less than 0.1 g/10 minutes, the extensibility during molding will be poor and the motor load in the extruder will be high, which is not preferred. On the other hand, if the MFR exceeds 100 g/10 minutes, the state of the molten film during 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, comonomer amount, etc. is taken. The MFR of the ethylene/propylene copolymer is measured according to JIS-K6922-2: 1997 Annex (190°C, 21.18N load).

(c-3) Density The ethylene/propylene copolymer (C) 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 unsatisfactory, which is not preferred. On the other hand, if the density exceeds 0.94 g/cm ³ , the adhesion will be 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 the catalyst, etc. is taken. The density of the ethylene/propylene copolymer is measured according to JIS-K6922-2:1997 Annex (for low-density polyethylene) (measurement temperature: 23°C).

(c-4) Total number of vinyl and vinylidene In a copolymer obtained by copolymerizing ethylene and one or more α-olefins, even if diene monomers are not positively added, the mechanism of the manufacturing process Due to the difference, various double bonds (vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted olefin) may occur, and the amounts and types thereof also vary.
Conventionally, in order to obtain good crosslinkability as a solar cell encapsulant, it was known that an ethylene/α-olefin copolymer containing a large number of double bonds would have good crosslinkability. In the field of lamination resin compositions, no consideration has been given to the differences depending on the amount and type of double bonds.
In the present invention, among the various double bonds contained in ethylene/propylene copolymers, it was found that vinyl and vinylidene are particularly important in terms of adhesive strength, and the total number of vinyl and vinylidene is the same as that of ordinary ethylene/propylene copolymers. We have found that the effect of the present invention can be achieved by producing an ethylene/propylene copolymer in a larger amount than the α-olefin copolymer and using it as an ethylene/propylene copolymer for a laminating resin composition. It is.

The ethylene/propylene copolymer (C) used in the present invention has a total number of vinyl and vinylidene double bonds per 1000 total carbon atoms in the main chain and side chains measured by NMR of 0.35 (number/ total 1000C) or more, preferably 0.40 to 5.0 (pieces/total 1000C), more preferably 0.45 to 4.5 (pieces/total 1000C), still more preferably 0.50 ~4.0 (pieces/total 1000C).
If the total number of vinyl and vinylidene is within the above range, the resin composition will have excellent adhesive strength, and if it is less than 0.35, the adhesive strength will not be sufficient. The total number of vinyl and vinylidene can be controlled within the above range by appropriately adjusting the selection of a suitable metallocene catalyst, polymerization temperature, comonomer species and comonomer amount.
The number of these double bonds is the number per 1,000 carbon atoms in total in the main chain and side chains, and is a value calculated using the integrated intensity of characteristic peaks in the ¹ H-NMR spectrum, which will be described later. It is a value calculated by measuring under the conditions described in Examples.

Furthermore, in the present invention, the number of vinyl atoms in the ethylene/propylene copolymer (C) preferably satisfies the range of 0.2 (number/total 1000C) or more.
In the present invention, the number of vinylidene atoms in the ethylene/propylene copolymer (C) preferably satisfies a range of 0.12 (number/total 1000C) or more.

(c-5) Relationship between number of branches (Y) and density (X) due to comonomer The ethylene/propylene copolymer (C) used in the present invention has the following number of branches (Y) and density (X) due to the comonomer. It is preferable to satisfy formula (1).
Formula (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 ensured, resulting in a resin composition having excellent adhesive strength.
Here, the number of branches (Y) due to the comonomer is the number per 1000 carbon atoms in total of the main chain and side chains measured by NMR of the ethylene/propylene copolymer (C) (number/total 1000C).
The density (X) is the density of the ethylene/propylene copolymer (C) and is measured as described above.

The number of branches (Y) due to the comonomer indicates the amount of tertiary carbon atoms contained in the polymer, and is the number per 1000 total carbon atoms of the main chain and side chains measured by NMR. W. Hansen, R.; Blom, and O. M. It can be calculated from the ¹³ C-NMR spectrum with reference to Bade, Polymer, 36, 4295 (1997).
The relationship between the density and the number of branches can be adjusted by adjusting the type and ratio of comonomers to be copolymerized and the polymerization conditions such as the polymerization temperature.

(c-6) Relationship between number of branches (Y) and density (X) due to comonomer The ethylene/propylene copolymer (C) used in the present invention has the following number of branches (Y) and density (X) due to the comonomer. More preferably, the formula (2) is satisfied.
Formula (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 monomer is sufficiently ensured, resulting in a resin composition excellent in adhesive strength.
Here, the number of branches (Y) due to the comonomer is the number per 1000 carbon atoms in total of the main chain and side chains measured by NMR of the ethylene/propylene copolymer (C) (number/total 1000C).
The density (X) is the density of the ethylene/propylene copolymer (C) and is measured as described above.

(ii) Polymerization catalyst and polymerization method for ethylene/propylene copolymer (C) The catalyst used for producing the ethylene/propylene copolymer (C) used in the present invention is not particularly limited, but is more preferably used. A metallocene catalyst is used.
Examples of metallocene catalysts include, but are not particularly limited to, catalysts comprising a metallocene compound such as a zirconium compound coordinated with a group having a cyclopentadienyl skeleton or the like and a cocatalyst as catalyst components. In particular, it is preferable to use a metallocene compound such as a zirconium compound coordinated with a group having a cyclopentadienyl skeleton.
The production method is not particularly limited, and a high-pressure ion polymerization method, a gas phase method, a solution method, a slurry method, or the like can be used. ), it is desirable to carry out polymerization at a high temperature of 150 to 330 ° C., so it is preferable to use a high-pressure ion polymerization method (“Polyethylene Technical Reader” Chapter 4, edited by Kazuo Matsuura and Naotaka Mikami, 2001 Year).

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

(i) Characteristics of high-pressure radical polymerization low-density polyethylene (D) (d-1) MFR
The melt flow rate (MFR: 190° C., 21.18N load) of the low-density polyethylene (D) 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 min. If the MFR is less than 0.1 g/10 minutes, the extensibility will be insufficient and film breakage will occur during high-speed molding. On the other hand, when the MFR exceeds 20 g/10 minutes, the molten film becomes unstable.
Here, MFR is a value measured according to JIS-K6922-2:1997 Annex (190° C., 21.18 N load).

(d-2) Density The density of the low-density polyethylene (D) 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 0.916 to 0.926 g/cm 3 . is between 0.917 and 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 adhesion becomes poor.
Here, the density is measured according to JIS-K6922-2:1997 Annex (for low-density polyethylene) (measurement temperature: 23°C).

(ii) High-pressure radical polymerization method Polymerization method of low-density polyethylene (D) Low-density polyethylene (D) used in the present invention is generally produced using a tank reactor or tubular reactor in the presence of a radical generator. Under the conditions of a polymerization pressure of 1000-3000 kg/cm ² and a polymerization temperature of 150-300° C., ethylene is polymerized. The MFR can be adjusted by using hydrogen or hydrocarbons such as methane and ethane as molecular weight modifiers.

(3) Composition ratio of ethylene-propylene copolymer (C) and low-density polyethylene (D) The polyethylene resin composition (E) used in the present invention is composed of ethylene-propylene copolymer (C) and low-density polyethylene (D). ), the ratio of the ethylene/propylene copolymer (C) and the high-pressure radical polymerization low-density polyethylene (D) is (C):(D), for example, 10 to 95% by weight: 5 to 90% by weight, preferably 20-95% by weight: 5-80% by weight, more preferably 30-95% by weight: 5-70% by weight. More preferably 40-95% by weight: 5-60% by weight. Too much ethylene/propylene copolymer (C) may reduce the stability of the melted film, and too much high-pressure radical polymerization low-density polyethylene (D) may reduce adhesive strength.
In particular, when the ratio (C:D) of the ethylene/propylene copolymer (C) and the high-pressure radical polymerization low-density polyethylene (D) is 50 to 95% by weight: 5 to 50% by weight, the adhesive strength increases. is preferred because it is higher.

(4) Properties of polyethylene resin composition (E) (e-1) MFR
The melt flow rate (MFR: 190° C., 21.18 N load) of the polyethylene resin composition (E) used in the present invention is preferably 1 to 100 g/10 min, more preferably 1 to 80 g/10 min. Yes, more preferably 2 to 70 g/10 minutes. If the MFR is less than 1 g/10 minutes, the spreadability during molding will be poor and the motor load in the extruder will be high, which is not preferred. On the other hand, if the MFR exceeds 100 g/10 minutes, the state of the molten film during molding becomes unstable, which is not preferable.
Here, MFR is a value measured according to JIS-K6922-2:1997 Annex (190° C., 21.18 N load).

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

(5) Other Components In the polyethylene resin composition (E) used in the present invention or the resin layer (A) containing the same, if necessary, phenol-based, phosphorus-based, etc., which are usually used for polyethylene-based resins. antioxidants, stabilizers such as metal soaps, anti-blocking agents, lubricants, dispersants, pigments such as organic or inorganic colorants, anti-fogging agents such as unsaturated fatty acid esters, antistatic agents, ultraviolet absorbers , a light stabilizer, and a nucleating agent. For example, a preferable blending range of the antioxidant is 5,000 ppm or less, more preferably 3,000 ppm or less, and still more preferably 1,000 ppm or less in terms of weight ratio.
Further, LDPE, C4-LLDPE, HAO-LLDPE, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-meta- Adhesion of acrylic acid copolymers (EMAA), ethylene-acrylate copolymers (EEA, EMA, EMMA, etc.), polyethylene resins such as high-density polyethylene (HDPE), ethylene-maleic anhydride copolymers, etc. Other thermoplastic resins such as resins, polypropylene-based resins, and polystyrene resins may be blended.
Moreover, it is preferable that the polyethylene resin composition ( E ) of the present invention does not contain a cross-linking agent.

2. Base layer (B)
The substrate layer (B) used in the present invention is a film essentially containing polyethylene terephthalate resin as a main component at least on the surface in contact with the resin layer (A), and is a single-layer film of polyethylene terephthalate or a polyethylene terephthalate-like or A laminated film made of different materials is exemplified. The film is preferably a stretched film. The amount of polyethylene terephthalate resin contained in the substrate layer (B) is, for example, 50% by weight to 100% by weight. When the substrate layer (B) contains a resin other than polyethylene terephthalate resin, the resins listed below as examples of the other substrate layer can be used.
The substrate layer may be subjected to printing, vapor deposition, various coatings, or the like.

3. Laminate The laminate of the present invention has at least two layers, a resin layer (A) containing the polyethylene resin composition (E) described above and a substrate layer (B), and the resin layer (A) is a substrate layer. (B) is a laminate formed by directly adhering to the top. A resin layer (A) containing a polyethylene resin composition (E) is directly adhered to at least one surface of the substrate layer (B).
Although there are no restrictions on the configuration of the laminate, examples include laminates having the following configurations.
Base layer (B)/resin layer (A) containing resin composition (E), resin layer (A) containing resin composition (E)/base layer (B)/resin composition (E) included Resin layer (A), base layer (B) / resin layer (A) containing resin composition (E) / base layer (B), resin layer (A) containing resin composition (E) / base Layer (B)/Resin Layer (A) Containing Resin Composition (E)/Base Layer (B), Base Layer (B)/Resin Layer (A) Containing Resin Composition (E)/Base Layer (B)/resin layer (A) containing resin composition (E)/base layer (B), base layer (B)/resin layer (A) containing resin composition (E)/other base layers , Other resin layer / base layer (B) / resin layer (A) containing resin composition (E), other base layer / base layer (B) / resin layer (A) containing resin composition (E) ), substrate layer (B)/resin layer (A) containing resin composition (E)/other resin layer Here, the other substrate layer is a substrate layer different from the substrate layer (B). , Examples include polypropylene resins, polyamide resins, polyester resins, ethylene-vinyl acetate copolymer saponified products, polyvinylidene chloride, polycarbonate plastic films or sheets, stretched products of the above films or sheets, printed matter, metals, etc. Examples include secondary processed films or sheets such as vapor deposition, metal foils or plates of aluminum, iron, copper, alloys containing these as main components, cellophane, paper, woven fabrics, non-woven fabrics, and the like.
Further, the other resin layer is a resin layer different from the resin layer (A), and examples include LDPE, C4-LLDPE, HAO-LLDPE, ethylene-vinyl acetate copolymer (EVA), Copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylate copolymer (EEA, EMA, EMMA, etc.), polyethylene resins such as high-density polyethylene (HDPE), ethylene-maleic anhydride Adhesive resins such as acid copolymers, polypropylene-based resins, polystyrene resins, and other thermoplastic resins can be used.

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

Also, the method for ensuring adhesion to the base material layer is not particularly limited, but for example, the base material may be subjected to surface treatment. Examples of surface treatment methods include various treatment methods such as corona discharge treatment, ozone treatment, flame treatment, and low-temperature plasma treatment. Alternatively, a method of blowing ozone onto the molten resin may be used. In addition, when providing another base material layer, it is preferable to carry out an anchor coat process as needed.

The laminate of the present invention is formed of the resin layer (A) containing the polyethylene resin composition (E), has excellent adhesive strength with the base layer (B), and has excellent content protection performance. is.

The laminate of the present invention has excellent adhesive strength with the base material layer (B), and can eliminate the use of an adhesive or the like. Therefore, it can be suitably used as clean packaging films, packages, etc. for food, medical care, electronic materials, and the like.

EXAMPLES The present invention will be specifically described below by way of 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. 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 low-density polyethylene, or polyethylene resin composition is measured in accordance with JIS-K6922-2: 1997 Annex (190°C, 21.18N load). bottom.
(2) Density As described above, the density of the ethylene/propylene copolymer, high-pressure radical polymerization low-density polyethylene, or polyethylene resin composition is specified in JIS-K6922-2: 1997 Annex (23°C, for low-density polyethylene). Measured according to

(3) The amount of comonomer, the number of branches and the number of double bonds due to the comonomer are determined by ¹³ C-NMR, and the number of double bonds (vinyl, vinylidene) are determined by ¹ H-NMR. Measurement was performed under the following conditions, and the number per 1000 carbon atoms in total in the main chain and side chains was obtained.
Apparatus: Bruker Biospin Co., Ltd. AVANCE III cryo-400 MHz
Solvent: o-dichlorobenzene/heavy bromobenzene = 8/2 mixed solution <sample amount>
460 mg of sample/2.3 ml of solvent
^<13C-NMR>
・¹ H decouple, with NOE ・Number of integrations: 256 scans
・Flip angle: 90°
・Pulse interval 20 seconds ・AQ (acquisition time) = 5.45 s D1 (waiting time) = 14.55 s
< ¹ H-NMR>
・Accumulation times: 1400 scans
・Flip angle: 1.03°
・AQ (acquisition time) = 1.8 s D1 (waiting time) = 0.01 s

(4) Melt Film Stability The stability of the melt film was visually observed with an extruder of 90 mmφ, a T-die width of 560 mm, 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. A case where the melted film was stable and could be processed was rated as "good", and a case where the melted film was unstable and could not be processed to a uniform thickness was rated as "poor".
(5) Adhesive strength The obtained laminate was cut into strips with a width of 15 mm in the machine direction, and the interface between the resin layer (A) and the base layer (B) was peeled off. The peel strength in the T peel test at a speed of 300 mm/min was defined as the adhesive strength. When the resin layer (A) was pulled and separated from the base material layer (B) and the layer was cut, the maximum numerical value on the chart was taken as the adhesive strength.

2. Material (1) Base layer (B)
Toyobo Ester Film E5102 (thickness: 25 μm) manufactured by Toyobo Co., Ltd. was used as a film containing polyethylene terephthalate resin as a main component at least on the surface in contact with the resin layer (A).

(2) Ethylene/propylene copolymer (C)
PE-1 obtained by the following production method was used as the ethylene/propylene copolymer (C). Table 1 shows its physical properties.

<Method for producing PE-1>
(i) Preparation of catalyst To 0.05 mol of the complex "rac-dimethylsilylenebisindenylhafnium dimethyl" prepared by the method described in JP-A-10-218921, an equivalent mol of "N,N-dimethylanilinium tetrakis (Pentafluorophenyl)borate” was added and diluted to 50 L with toluene to prepare a catalyst solution.

(ii) Polymerization method Using a stirring autoclave-type continuous reactor with an internal volume of 5.0 L, maintaining the pressure in the reactor at 80 MPa, and adjusting ethylene, propylene, and 1-hexene as appropriate, at a rate of 55 kg / hour. Raw material gas was continuously supplied. In addition, the catalyst solution described in the section “(i) Adjustment of catalyst” is continuously supplied, and the polymerization temperature is appropriately adjusted within the range of 200 to 250 ° C. to copolymerize PE-1 with ethylene and propylene. got a union.

(3) High pressure radical polymerization low density polyethylene (D)
High-pressure radical polymerization low-density polyethylenes (PE-2) to (PE-3) having physical properties shown in Table 1 were used.

(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. These were thoroughly mixed and pellets of the polyethylene resin composition (E) were obtained using a 40 mmφ single screw extruder.
The pellets obtained above are set so that the temperature of the resin extruded from a T-die attached to an extruder with a diameter of 90 mmφ is 325 ° C., using an extrusion lamination molding machine, the cooling roll surface temperature is 25 ° C., the die When the width is 560 mm, the die lip opening is 0.8 mm, and the take-up processing speed is 100 m / min, the coating thickness is adjusted to 15 μm, and a biaxially oriented polyethylene terephthalate film (Toyobo Ester Film manufactured by Toyobo Co., Ltd.) with a width of 500 mm and a thickness of 25 μm E5102) as a base layer (B), and a linear low-density polyethylene (LLDPE) film (LL-XMTN manufactured by Futamura Chemical Co., Ltd.) with a thickness of 30 μm as a sand base layer, and subjected to extrusion sand lamination to produce a laminate. bottom. Next, the obtained laminate was used to evaluate the adhesive strength described above. Table 1 shows the evaluation results.

(Example 2)
A laminate was produced in the same manner as in Example 1, except that 510 ppm by weight of antioxidant was added. Table 1 shows the evaluation results.

(Comparative example 1)
In Example 1, the ethylene/propylene copolymer (C) was not used, and the polyethylene resin composition (E) consisting only of PE-3, which is a high-pressure radical polymerization low-density polyethylene (D), was used. A laminate was produced in the same manner as in Example 1. Table 1 shows the evaluation results.

(evaluation)
As is clear from the results in Table 1, the laminates according to the examples of the present invention are laminates having excellent adhesion strength to the polyethylene terephthalate resin film.
On the other hand, when only high-pressure radical polymerization low-density polyethylene was used (Comparative Example 1), the adhesive strength was small.

The laminate of the present invention can be used as clean packaging films, packages, etc. for food, medical care, electronic materials, and the like.

Claims (7)

Having at least two layers, a resin layer (A) and a substrate layer (B),
A package characterized in that the resin layer (A) is formed by directly adhering to the substrate layer (B), and the resin layer (A) and the substrate layer (B) each satisfy the following properties: Laminate for
Resin layer (A): contains an ethylene/propylene copolymer (C) having the following properties (c-1) to (c-4) and contains a polyethylene resin composition (E) containing no cross-linking agent ( c-1) A copolymer obtained by randomly polymerizing a substantially straight chain, containing 80 to 98 mol% of a structural unit derived from ethylene as a main component, and a structural unit derived from propylene as an essential subcomponent. 2 to 20 mol%, and may contain 5 mol% or less of a structural unit derived from a third α-olefin other than ethylene and propylene as a subcomponent (however, the structural unit derived from the third α-olefin When it is included, the total of structural units derived from ethylene, structural units derived from propylene, and structural units derived from the third α-olefin does not exceed 100 mol%)
(c-2) MFR (190°C, 21.18N load) is 0.1 to 100 g/10 minutes (c-3) Density is 0.88 to 0.94 g/cm ³
(c-4) The total amount of vinyl and vinylidene in the ethylene/propylene copolymer is 0.35 (number/total 1000C) or more (however, the number of vinyl and vinylidene is the number of main chain and side chain measured by NMR) It is the number per 1000 total carbon numbers.)
Base layer (B): A film containing polyethylene terephthalate resin as a main component at least on the surface in contact with the resin layer (A) 2. The polyethylene resin composition (E) according to claim 1, wherein the polyethylene resin composition (E) contains a high-pressure radical polymerization low-density polyethylene (D) having the following properties (d-1) to (d-2): Laminates for packaging .
(d-1) MFR (190°C, 21.18N load) is 0.1 to 20 g/10 minutes (d-2) Density is 0.915 to 0.930 g/cm ³ A claim characterized in that the polyethylene resin composition (E) contains 95 to 10% by weight of an ethylene/propylene copolymer (C) and 5 to 90% by weight of a high-pressure radical polymerization low-density polyethylene (D). 2. The laminate for packaging according to 2 above. The packaging laminate according to any one of claims 1 to 3, wherein the ethylene/propylene copolymer (C) further satisfies the following property (c-5).
(c-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).
Formula (1): (Y)≧−1157×(X)+1080
(However, Y is the number per 1000 total carbon atoms of the main chain and side chains measured by NMR.) The packaging laminate according to any one of claims 1 to 4, wherein the ethylene/propylene copolymer (C) further satisfies the following property (c-6).
(c-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).
Formula (2): (Y)≧−1157×(X)+1084
(However, Y is the number per 1000 total carbon atoms of the main chain and side chains measured by NMR.) The packaging laminate according to any one of claims 1 to 5, wherein the polyethylene resin composition (E) further satisfies the following properties (e-1) to (e-2).
(e-1) MFR is 1 to 100 g/10 minutes (e-2) Density is 0.88 to 0.94 g/cm ³ The method for producing a laminate for packaging according to any one of claims 1 to 6, wherein the laminate is formed by an extrusion coating method.