JP2010076341A - Multilayer laminated film with easy peelability and transparency - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer laminated film combining practicability and fine appearance with excellent peelability and transparency when used as a cover material of a container without stringiness or the like of a peel part, and a packaging container using the multilayer laminated film as the cover material. <P>SOLUTION: The multilayer laminated film having a seal resin layer (A)1 and a base material resin layer (B)2 is formed by laminating the base material resin layer (B) comprising a low-density polyethylene or ethylene-α-olefine copolymer, on the seal resin layer (A) comprising (i) 90-30 pts.wt of low-density polyethylene or ethylene-α-olefine copolymer with a density of 0.915-0.930 g/cm<SP>3</SP>and (ii) 10-70 pts.wt. of propylene elastomer with a density of 0.850-0.89 g/cm<SP>3</SP>. The layer thickness of the seal resin layer (A) is 1-20 μm, and the layer thickness of the base material resin layer (B) is 20-100 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a multilayer laminated film mainly used as a lid for packaging containers for foods, chemical products, etc. in the field of soft packaging, and is excellent in easy-opening and transparency, and stringing of the peel part, etc. The present invention relates to a multilayer laminated film having both practicality and aesthetics and a packaging container using the same as a lid.

In recent years, packaging containers are required not only to sufficiently satisfy sealing properties for content protection and storage, but also to be easily opened (easy peel) that can be easily opened when consumed. Various proposals have been made as packaging films having both practical sealing properties and easy opening properties.
For example, as a film intended for easy opening, a heat-sealable laminated film composed of two layers of a blend layer of various acrylic acid copolymers and polyethylene (see Patent Document 1), a base material layer composed of polypropylene, A film in which a three-component blend layer of polybutene, polypropylene, and polyethylene is laminated (see Patent Document 2), a multilayer film having a layer made of a mixture of a methacrylic acid copolymer and polypropylene, and a polyethylene sealant layer (see Patent Document 3) There is known an easy peel film comprising a base material layer made of polypropylene and a blend layer of polybutene, polyethylene and polypropylene (see Patent Document 4).
JP-A-5-212835 JP-A-6-328639 JP 2002-283513 A JP-A-6-328639

  However, conventional films intended for easy opening have a high material cost, have a low degree of freedom in film forming conditions (blending conditions, etc.), and polybutene blended for the purpose of improving low-temperature sealing properties, etc. It was also not sufficient in terms of the beauty of the peeled surface. In addition, from the viewpoint of improving the product image during store display and the demand of consumers who want to confirm the appearance of the contents before purchasing the product, the development of lid materials with high transparency and excellent contents visibility is strong. It was desired.

  Therefore, as a result of various studies to solve the above problems, the present inventor, as a material constituting the sealing resin layer (A) in the multilayer laminated film for the lid of the packaging container, An ethylene-α-olefin copolymer and a propylene elastomer are used, and the sealing resin layer is composed of a two-component system comprising (i) a low density polyethylene or an ethylene-α-olefin copolymer and (ii) a propylene elastomer. The desired peel strength can be obtained by using a low-density polyethylene or ethylene-α-olefin copolymer having a relatively low crystallinity as a material constituting the base resin layer (B), Discovered that transparency can be given to the multilayer film, and that stringing after peeling can be reduced or suppressed, and excellent easy-openability and contents It has 認性, and release surface has developed a multi-layer laminated film for cover material of beautiful packaging container.

That is, this invention includes the invention shown to the following (1)-(8).
(1) A multilayer laminated film having a sealing resin layer (A) and a base resin layer (B),
The multilayer laminated film, (i) a density as low density polyethylene or ethylene -α- olefin copolymer 90 to 30 parts by weight of 0.915~0.930g / cm ³ (ii) density of 0.850~0.89g / cm ³ The propylene elastomer consists of 10 to 70 parts by weight, and the seal resin layer (A) in which the total of (i) and (ii) is 100 parts by weight is composed of low density polyethylene or ethylene-α-olefin copolymer. The base resin layer (B) is laminated,
A multilayer laminated film, wherein the sealing resin layer (A) has a thickness of 1 to 20 μm, and the base resin layer (B) has a thickness of 20 to 100 μm.

(2) The propylene elastomer used for the seal resin layer (A) is an ethylene / propylene random copolymer, and the MFR (230 ° C.) is 1 to 12 g / 10 min. Multi-layer laminated film.
(3) The MFR (230 ° C.) of the low density polyethylene or ethylene-α-olefin copolymer constituting the base resin layer (B) is from 1 to 10 g / 10 min. Multi-layer laminated film.

(4) A lid base material layer (C) selected from a stretched film obtained by depositing a stretched film and a barrier layer on the surface of the base resin layer (B) opposite to the seal resin layer (A). One layer or two layers are further laminated | stacked, The multilayer laminated film in any one of (1)-(3) characterized by the above-mentioned.
(5) The multilayer laminated film according to (4), wherein the inorganic oxide is alumina or silica.
(6) The multilayer laminated film of (4) or (5), wherein the multilayer laminated film has a haze value of 40% or less.

(7) A packaging container using the multilayer laminated film according to any one of (4) to (6) as a lid, wherein the sealing resin layer (A) of the lid is an opening of the container formed of polyethylene A packaging container that is heat-sealed in a state where it is in contact with each other, and the sealing resin layer (A) of the lid material is cohered and broken when opened.
(8) The method for producing a multilayer laminated film according to any one of (1) to (3), wherein an inflation film forming method is used.

  Since the multilayer laminated film of the present invention is excellent in easy-opening property and transparency and has a beautiful peeled surface, a container using this as a lid is excellent in both practicality and aesthetics.

  That is, the multilayer laminated film of the present invention comprises a general-purpose resin two-component system in which the sealing resin layer (A) is incompatible, and the sea-island structure can be controlled by controlling the blend ratio and MFR (melt mass flow rate) of this layer. Can be controlled and can achieve an appropriate cohesive failure strength, reducing or inhibiting stringing after peeling, having excellent easy opening properties, and having a peelable surface after opening. A multilayer laminated film for a material can be provided. Furthermore, in this invention, since the low-density polyethylene with a comparatively small crystallinity degree or an ethylene-alpha-olefin copolymer is used as a base resin layer (B), the multilayer laminated film of this invention was excellent. It has transparency.

  In addition, the multilayer laminated film of the present invention can be produced by various methods known to those skilled in the art, but is preferably produced also by an inflation film-forming method that can be produced at low cost even in the case of a small lot. Can do. The inflation film-forming method is a film-forming method suitable for the production of various types of small quantities, but the application range is narrow and can be used only for limited materials. That is, the conventional easy-open (easy peel) film is relatively expensive, while the multilayer laminated film of the present invention can be applied with a general-purpose and inexpensive material and an inflation film-forming method. Therefore, there is a merit in terms of cost.

  In addition, by providing a transparent stretched film or a stretched film on which an inorganic oxide is deposited on the surface of the base resin layer (B) as a lid base material layer (C), the haze value is 40%. Therefore, it is possible to provide a multilayer laminated film having a gas barrier property suitable for long-term storage of the contents.

The multilayer laminated film of the present invention will be described in detail below.
The multilayer laminated film of the present invention comprises a sealing resin layer (A) and a base resin layer (B), and the base resin layer (B) is one layer or two layers or more, preferably one layer or two layers. It is. FIG. 1 shows an example in which the base resin layer (B) is composed of one layer, and is composed of a low density polyethylene or an ethylene-α-olefin copolymer in contact with the seal resin layer (A). A multilayer laminated film having a two-layer structure in which resin layers are laminated.

Next, materials constituting the multilayer laminated film of the present invention, manufacturing methods thereof, and the like will be described.
Hereinafter, the resin names used in the present invention are those commonly used in the industry. Moreover, the density said to this invention means what was measured based on "JISK7112".

<1> Seal resin layer (A)
(1) Low density polyethylene or ethylene-α-olefin copolymer constituting the sealing resin layer (A) In the present invention, the material constituting the sealing resin layer (A) is low density polyethylene or ethylene-α-olefin. A copolymer is used. Here, the ethylene-α-olefin copolymer includes a block or random copolymer of ethylene and another α-olefin (for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc.). Is included. In the present invention, as the sealing resin layer (A), it is particularly preferable to use low-density polyethylene or a random copolymer of ethylene and 1-butene from the viewpoint of easy opening and transparency.
The density of the low-density polyethylene and ethylene-α-olefin copolymer constituting the sealing resin layer (A) is 0.915 to 0.930 g / cm ³ . Moreover, as said low density polyethylene and ethylene-alpha-olefin copolymer, MFR (190 degreeC) is 1-9 g / 10min, Preferably it is 1-7 g / 10min, and resin with comparatively high melt viscosity is used. It is desirable to use it.

In the above, if the density exceeds 0.930 g / cm ³ , for example, high density polyethylene or medium density polyethylene is used, the crystallinity is high and the transparency is lowered. In addition, if the density is less than 0.915 g / cm ³ , it is difficult to form a film by the inflation film forming method because of high fluidity, and the slipperiness of the film is deteriorated and the processability is inferior. It becomes. On the other hand, if the MFR (190 ° C.) is less than 1 g / 10 minutes, the flowability is lowered, and thus the production becomes difficult. On the other hand, when the above specified range is exceeded, the film-forming stability is inferior. Here, the MFR (190 ° C.) referred to in the present invention means a value measured according to “JIS K6922”.
Examples of the low density polyethylene and ethylene-α-olefin copolymer suitable for use in the present invention include Evolu from Prime Polymer, Novatec LD from Nippon Polyethylene.

(2) Propylene Elastomer Constructing Seal Resin Layer (A) In the present invention, the propylene elastomer constituting the seal resin layer (A) includes propylene homopolymer, and block or random of propylene and other α-olefin. Copolymers are included. Here, the α-olefin includes, for example, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc. In order to obtain an appropriate seal strength, a random mixture of propylene and ethylene is used. A propylene elastomer made of a copolymer is particularly preferred.

As the propylene elastomer, one having a density of 0.850 to 0.89 g / cm ³ , preferably 0.850 to 0.88 g / cm ³ is used. Moreover, it is preferable to use what has MFR (230 degreeC) of 1-12 g / 10min. An MFR (230 ° C.) of less than 1 g / 10 minutes is not preferable because unevenness occurs in the sealing resin layer (A). Moreover, when MFR (230 degreeC) exceeds 12 g / 10min, the slipperiness | lubricity of the seal | sticker resulting from a low molecular weight component and a low elastic modulus will fall, and it will be inferior to the workability at the time of dry lamination. Here, the MFR (230 ° C.) referred to in the present invention means a value measured according to “JIS K6921”.
In the seal resin layer (A), the low density polyethylene or ethylene-α-olefin copolymer and the propylene elastomer have a sea-island structure because they are incompatible, but the propylene elastomer is a propylene-ethylene copolymer. By using a polymer and increasing the ethylene content, compatibility with low-density polyethylene or ethylene-α-olefin copolymer can be improved, and the seal strength can be increased.
Suitable propylene elastomers for use in the present invention include, for example, Versify manufactured by Dow Chemical Co., Adflex manufactured by Basel.

(3) Blend ratio The blend ratio of the low-density polyethylene or ethylene-α-olefin copolymer and propylene elastomer in the seal resin layer (A) is 90-30 parts by weight, preferably 90-60 parts by weight of low-density polyethylene or It is desirable to comprise ethylene-α-olefin and 10 to 70 parts by weight, preferably 10 to 40 parts by weight of propylene elastomer.
If the content of the propylene elastomer is higher than the above range, the adhesive strength becomes too high and good easy-openability cannot be obtained, and if it is lower than the above range, sufficient adhesive strength cannot be obtained and the sealing performance as a packaging container is not obtained. I'm not satisfied.

  Further, the blend ratio is preferably changed in accordance with the adhesive strength required between the adherend and the adherend within the specified value range. For example, when the sealing layer of the packaging container is polyethylene, the sealing resin layer It is possible to improve the sealing strength by increasing the content of polyethylene or ethylene-α-olefin copolymer of (A), and when the sealing layer of the packaging container is polypropylene, the content of propylene elastomer is increased. Thus, the seal strength can be improved.

<2> Base resin layer (B)
Since the base resin layer (B) of the multilayer laminated film of the present invention does not directly contact the adherend, it is not necessary to provide an easy-open function (easy peel function), but it imparts transparency to the lid. To do this, use the following:
That is, in the present invention, low-density polyethylene or ethylene-α-olefin copolymer is used as the base resin layer (B). Here, the α-olefin includes, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and the like, and in particular, ethylene-propylene copolymer polymerized with a metallocene catalyst or a multisite catalyst. The coalescence is preferable from the viewpoint of film formation stability because the molecular weight distribution is sharp. Further, it is desirable from the viewpoint of transparency to use a material having a density of 0.910 to 0.930 g / cm ³ , preferably 0.915 to 0.925 g / cm ³ .
Moreover, when manufacturing by an inflation film forming method, it is preferable that MFR (230 degreeC) is 1-10 g / 10mins for the resin which comprises a base resin layer (B). By defining within this range, the multilayer laminated film of the present invention can be satisfactorily manufactured by the inflation film forming method.
As the base resin layer (B), one type or two or more types of the above-described resins are used, and one layer or two layers or more, preferably one layer or two layers can be laminated on the seal resin layer (A).

<3> Layer Thickness Regarding the sealing resin layer (A), the layer thickness is 1 to 20 μm, preferably 1 to 10 μm. When the above range is exceeded, the release layer (cohesive failure layer) becomes dirty, the release surface is inferior in beauty, and the cost increases. Moreover, desired adhesiveness is not acquired as it is less than 1 micrometer.
On the other hand, the thickness of the base resin layer (B) is preferably 20 to 100 μm.

<4> Method for producing multilayer laminated film of the present invention comprising a sealing resin layer (A) and a base resin layer (B) Next, the multilayer of the present invention comprising a sealing resin layer (A) and a base resin layer (B) The manufacturing method of a laminated film is demonstrated. The laminating step in this production method is a method of laminating ordinary packaging materials, for example, wet lamination method, dry lamination method, solventless dry lamination method, extrusion lamination method, T-die extrusion molding method, coextrusion lamination method, inflation Although it can be performed by various methods known to those skilled in the art, such as a film forming method and a coextrusion inflation film forming method, among others, use an inflation film forming method that can be manufactured at low cost even in the case of a small lot. Is preferred.

<5> Lid base material layer (C)
On the surface of the base resin layer (B) of the multilayer laminated film of the present invention, as a lid base material layer (C), various transparent packaging materials, for example, stretched films, are laminated by one layer or two or more layers. be able to.
In the present invention, as the “stretched film”, polyesters such as polyethylene terephthalate, polybutylene terephthalate and 6-naphthalate, and polyamides such as nylon 6 and nylon 66 are used. Particularly preferable stretched films include stretched films made of polyester (polyethylene terephthalate), polyamide (nylon 6, nylon 66, nylon 6-66), etc., which are excellent in transparency, mechanical strength and packaging suitability. By laminating various stretched films on the multilayer laminated film of the present invention, the physical strength of the film is improved, and favorable properties for heat treatment such as heat shrinkability are imparted.
The packaging material as described above can be laminated by, for example, a dry lamination method, a solventless lamination method, an extrusion lamination method, a coextrusion lamination method, or the like.

  Moreover, in this invention, it is preferable to use what provided the gas-barrier layer on the said stretched film as a lid | cover material base for the purpose of improving a gas-barrier property further. As such a gas barrier layer, inorganic metal oxides such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), Examples include boron (B), titanium (Ti), lead (Pb), zirconium (Zr), oxides such as yttrium (Y), preferably vapor-deposited films of alumina and silica. The film thickness of the inorganic oxide vapor-deposited film varies depending on the metal to be used or the type of metal oxide, etc., but from the viewpoint of gas barrier properties, for example, it is optional within the range of 50 to 2000 mm, preferably 100 to 1000 mm. Can be selected. The inorganic oxide vapor-deposited film can be provided on the stretched film by physical vapor deposition or chemical vapor deposition.

Furthermore, in the present invention, for the purpose of further improving the gas barrier property, a gas barrier coating film developed by the present applicant, that is, the general formula: R ¹ _n M (OR ² ) _m (wherein M is a metal atom, R ¹ and R ² are organic groups having 1 to 8 carbon atoms, n is 0 or more, m is an integer of 1 or more, and n + m represents a valence of M), and at least one alkoxide, polyvinyl alcohol, and A gas barrier coating film made of a gas barrier composition obtained by polycondensation of a composition containing ethylene / vinyl alcohol by a sol-gel method may be provided on the inorganic oxide vapor-deposited film.
Various stretched films, or various stretched films provided with a gas barrier layer and a gas barrier coating film are transparent. By using these, the haze value can be suppressed to a low value of 40% or less. The lid material can be made beautiful and excellent in contents visibility. In addition, the haze value as used in the field of this invention means the value measured based on JIS K-7105.

<6> Physical Properties Next, factors in setting physical properties required for the multilayer laminated film of the present invention will be described.
(1) Cohesive failure (cohesive peeling) strength The easy-openability or cohesive failure strength of the multilayer laminated film of the present invention is controlled by low-density polyethylene or ethylene-α-olefin copolymer and propylene used for the seal resin layer (A). This is done by changing the blending ratio of the elastomer.

(2) Transparency The transparency of the multilayer laminated film of the present invention is controlled by the density of the low density polyethylene or ethylene-α-olefin copolymer used for the sealing resin layer (A) and the base resin layer (B). This is done by controlling.
Specifically, for the sealing resin layer (A), a low-density polyethylene or ethylene-α-olefin copolymer having a density of 0.910 to 0.930 g / cm ^{3 and} a relatively small crystallinity is used. When the density exceeds 0.930 g / cm ³ , for example, high-density polyethylene or medium-density polyethylene is used, the desired transparency cannot be obtained due to high crystallinity.
The base resin layer (B) has a density of 0.910 to 0.930 g / cm ³ , preferably 0.915 to 0.925 g / cm ^{3 and} has a relatively low crystallinity and is polymerized with a low density polyethylene or metallocene catalyst. It is desirable to use an α-olefin copolymer. If the density exceeds the above range, the crystallinity is high, so that the desired transparency cannot be obtained.

<7> Configuration of lid material Next, the configuration of an example of the lid material of the packaging container using the multilayer laminated film of the present invention will be described with reference to FIG. The lid of the packaging container in FIG. 2 has a laminated adhesive layer printed as necessary on a multilayer laminated film composed of the sealing resin layer (A) and the base resin layer (B) according to the present invention. The lid base material layer (C) is further laminated on the laminated one.

<8> Packaging container The multilayer laminated film of the present invention is used for a sealant film for a lid of a packaging container. In particular, it is used for cup-shaped packaging containers in which the adhesive surface of the lid of the container opening is heat-sealed to the opening of the container formed of polyethylene, and the sealing resin layer (A) of the lid is coherently broken when opened. Opened. Such a packaging container may be formed with a plurality of containers via flanges, and in that case, means for separating the containers from the flanges, for example, a sewing machine that penetrates the flanges and lids of the containers. Eyes can also be provided.

The present invention will be described more specifically with reference to examples.
[Example 1]
(1) Seal resin layer (A)
As a resin composition for the sealing resin layer (A), 70 parts by weight of low density polyethylene (Novatec LD LC522 manufactured by Nippon Polyethylene Co., Ltd .: density = 0.93 g / cm ³ , MFR (190 ° C.) = 4.0 g / 10 min),
30 parts by weight of a propylene elastomer (Versify V3300 manufactured by Dow Chemical Co., Ltd .: density = 0.876 g / cm ³ , MFR (230 ° C) = 8 g / 10 min) was sufficiently kneaded and prepared.

(2) Base resin layer (B)
As a resin composition for the base resin layer (B-1), an ethylene-α-olefin copolymer polymerized using a metallocene catalyst (Evolue SP2020 manufactured by Prime Polymer Co., Ltd .: density = 0.923 g / cm ³ , MFR (230 ° C. ) = 2.3 g / 10 min).
Furthermore, as a resin composition for the base resin layer (B-2), low density polyethylene (Novatic LD LC522, manufactured by Nippon Polyethylene Co., Ltd .: density = 0.923 g / cm ³ , MFR (230 ° C.) = 4.0 g / 10 min) 100 parts by weight of the resin was prepared.
Using a top-blown air-cooled inflation coextrusion film forming machine, a multilayer laminated film having a total thickness of 50 μm (sealing resin layer (A) 5 μm / base resin layer (B-2) 20 μm / base resin layer (B-1) 25 μm ) Was manufactured.

Next, the surface of the base resin layer (B-1) is subjected to corona treatment, and a two-component curable urethane adhesive (main component: polyester polyol, curing agent: aliphatic isocyanate) is applied to the surface, and the lid base As the material layer (C), CVD (Chemical Vapor Deposition) silica vapor-deposited stretched PET film (IB-PET-UB manufactured by Dai Nippon Printing Co., Ltd. <single side treatment>: thickness 12 μm) and biaxially stretched ONy film (Unitika) [Emblem NX] <Both side treatment>: 15 μm thickness) manufactured by Co., Ltd. was sequentially laminated. The obtained laminate has a structure of silica-deposited PET12 / DL / ONy15 / DL / base resin layer (B) / seal resin layer (A) (DL means an adhesive part).
The haze value of the multilayer laminate produced above was measured using a haze computer (manufactured by Suga Test Instruments Co., Ltd .: HGM-2DP).
Next, the multilayer laminate was heat sealed from a flat seal to a cup-shaped container (diameter 74φ, flange width 5 mm, capacity 120 cc) made of polyethylene resin under conditions of a seal temperature of 170 ° C., 3 kg / cm ² , and 1 second. Thereafter, a 15 mm wide test piece was prepared from the cup, and the seal strength was measured by 180 ° peeling at a test speed of 300 mm / min. It was confirmed that the obtained multilayer laminate had an appropriate sealing strength, had a beautiful peeled appearance, and had transparency.

[Example 2]
(1) Seal resin layer (A)
As a resin composition for the sealing resin layer (A), low-density polyethylene (Prime Polymer Evolue SP1085: density = 0.919 g / cm ³ , MFR (190 ° C.) = 8.0 g / 10 min) 60 parts by weight, propylene elastomer 40 parts by weight (Dow Chemical Versify V2200: density = 0.888 g / cm ³ , MFR (230 ° C.) = 8.0 g / 10 min) was sufficiently kneaded and prepared.

(2) Base resin layer (B)
As a resin composition for the base resin layer (B), an ethylene-α-olefin copolymer polymerized using a metallocene catalyst (Novatec C6 SF240 manufactured by Nippon Polyethylene Co., Ltd .: density = 0.920 g / cm ³ , MFR (230 ° C.) = 1.9 g / 10 min) 100 parts by weight of a resin was prepared.
A multi-layer laminated film (seal resin layer (A) 5 μm / base resin layer (B) 45 μm) having a total thickness of 50 μm was produced using a top-blown air-cooled inflation coextrusion film forming machine.
Thereafter, the same results as in Example 1 were obtained.

[Example 3]
(1) Seal resin layer (A)
As a resin composition for the sealing resin layer (A), low-density polyethylene (Novatec LD LF443 manufactured by Nippon Polyethylene Co., Ltd., density = 0.922 g / cm ³ , MFR (190 ° C.) = 1.5 g / 10 min) 50 parts by weight, propylene 50 parts by weight of an elastomer (Versify V3200 manufactured by Dow Chemical Co., Ltd .: density = 0.866 g / cm ³ , MFR (230 ° C.) = 2.0 g / 10 min) was sufficiently kneaded and prepared.

(2) Base resin layer (B)
As a resin composition for the base resin layer (B), an ethylene-α-olefin copolymer polymerized using a metallocene catalyst (Evolue ST2520 manufactured by Prime Polymer Co., Ltd .: density = 0.925 g / cm ³ , MFR (230 ° C.) = 1.9 g / 10 min) was prepared in an amount of 100 parts by weight.
A multi-layer laminated film (seal resin layer (A) 5 μm / base resin layer (B) 45 μm) having a total thickness of 50 μm was produced using a top-blown air-cooled inflation coextrusion film forming machine.
Thereafter, the same results as in Example 1 were obtained.

[Comparative Example 1]
(1) Seal resin layer (A)
As a resin composition for the sealing resin layer (A), low-density polyethylene (Prime Polymer Evolue SP1085: density = 0.919 g / cm ³ , MFR (190 ° C.) = 8.0 g / 10 min) 60 parts by weight, propylene elastomer 40 parts by weight (Dow Chemical Versify V2200: density = 0.888 g / cm ³ , MFR (230 ° C.) = 8.0 g / 10 min) was sufficiently kneaded and prepared.

(2) Base resin layer (B)
As a resin composition for the base resin layer (B), 100 weight of resin which is high density polyethylene (Hi-Zex 3300F manufactured by Prime Polymer Co., Ltd .: density = 0.950 g / cm ³ , MFR (230 ° C.) = 1.1 g / 10 min) A portion was prepared.
A multi-layer laminated film (seal resin layer (A) 5 μm / base resin layer (B) 45 μm) having a total thickness of 50 μm was produced using a top-blown air-cooled inflation coextrusion film forming machine.
Hereinafter, various physical properties were evaluated in the same manner as in Example 1, but it was confirmed that the multilayer laminated film was inferior in transparency.

[Comparative Example 2]
(1) Seal resin layer (A)
As a resin composition for the sealing resin layer (A), low-density polyethylene (Prime Polymer Evolue SP2020: density = 0.923 g / cm ³ , MFR (190 ° C.) = 3.0 g / 10 min) 60 parts by weight, propylene elastomer 40 parts by weight (Dow Chemical Company Versify V2300: density = 0.867 g / cm ³ , MFR (230 ° C.) = 25 g / 10 min) was sufficiently kneaded and prepared.

(2) Base resin layer (B)
As a resin composition for the base resin layer (B), an ethylene-α-olefin copolymer polymerized using a metallocene catalyst (Evolue ST2520 manufactured by Prime Polymer Co., Ltd .: density = 0.925 g / cm ³ , MFR (230 ° C.) = 1.9 g / 10 min) was prepared in an amount of 100 parts by weight.
A multi-layer laminated film (seal resin layer (A) 5 μm / base resin layer (B) 45 μm) having a total thickness of 50 μm was manufactured using a top blown air-cooled inflation coextrusion film forming machine, but blocked with a nip roll of the film forming machine. As a result, film formation could not be performed.

[result]
Table 1 summarizes the seal strengths and haze values measured in the above Examples and Comparative Examples.
These physical properties were measured as follows.
(1) Layer thickness: Measured with a μ-meter manufactured by SONY Corporation.
(2) Seal strength: A polypropylene cup was sealed from a flat seal under the conditions of a seal temperature of 170 ° C., 3 kg / cm ² , and 1 second. A strip-shaped test piece having a width of 15 mm was cut out from the tensile tester, and a tensile test was performed at 300 mm / min.
(3) Haze value: Measured using a haze computer (manufactured by Suga Test Instruments Co., Ltd .: HGM-2DP).

As described above, it was confirmed that each of the multilayer laminated films of Examples 1 to 3 showed favorable sealing strength and excellent easy-openability, and had good transparency.
On the other hand, the multilayer laminated film of Comparative Example 1 uses high-density polyethylene as the base resin layer (B), but is extremely inferior in transparency. Further, in the multilayer laminated film of Comparative Example 2, the MFR of the propylene elastomer used for the seal resin layer (A) is as high as 25 g / 10 min, but it cannot be produced by the inflation film forming method. It was confirmed that there was.

It is sectional drawing which shows the layer structure of the multilayer laminated film of this invention. It is sectional drawing which shows the layer structure of the multilayer laminated film of this invention.

Explanation of symbols

1 Sealing resin layer (A)
2 Base resin layer (B)
3 Laminate Adhesive Layer 4 Printing Layer 5 Lid Base Material Layer (C)

Claims (8)

A multilayer laminated film having a sealing resin layer (A) and a base resin layer (B),
The multilayer laminated film, (i) a density as low density polyethylene or ethylene -α- olefin copolymer 90 to 30 parts by weight of 0.915~0.930g / cm ³ (ii) density of 0.850~0.89g / cm ³ The propylene elastomer consists of 10 to 70 parts by weight, and the seal resin layer (A) in which the total of (i) and (ii) is 100 parts by weight is composed of low density polyethylene or ethylene-α-olefin copolymer. The base resin layer (B) is laminated,
A multilayer laminated film, wherein the sealing resin layer (A) has a thickness of 1 to 20 μm, and the base resin layer (B) has a thickness of 20 to 100 μm.   2. The multilayer according to claim 1, wherein the propylene elastomer used for the sealing resin layer (A) is an ethylene / propylene random copolymer, and the MFR (230 ° C.) is 1 to 12 g / 10 min. Laminated film.   The multilayer according to claim 2, wherein the MFR (230 ° C) of the low-density polyethylene or ethylene-α-olefin copolymer constituting the base resin layer (B) is 1 to 10 g / 10 min. Laminated film.   One surface of the base material layer (C) selected from a stretched film and a stretched film obtained by depositing an inorganic oxide on the surface of the base resin layer (B) on the side opposite to the seal resin layer (A) or Two layers are further laminated | stacked, The multilayer laminated film as described in any one of Claims 1-3 characterized by the above-mentioned.   The multilayer laminated film according to claim 4, wherein the inorganic oxide is alumina or silica.   The multilayer laminated film according to claim 4 or 5, wherein the multilayer laminated film has a haze value of 40% or less.   It is a packaging container which uses the multilayer laminated film of any one of Claims 4-6 as a cover material, Comprising: The sealing resin layer (A) of this cover material contacts the opening part of the container formed with polyethylene. A packaging container that is heat-sealed in such a stacked state, and is opened when the sealing resin layer (A) of the lid material is coherently broken when opened.   The method for producing a multilayer laminated film according to any one of claims 1 to 3, wherein an inflation film forming method is used.

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