JP3349947B2 - Laminated film, lid material and container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, a lid made of the laminated film, and a container made of the laminated film.

[0002]

2. Description of the Related Art In packaging materials, it is common to form a laminate in which a heat seal (sealant) layer is formed on a base material. Examples of the sealant material include polyethylene, polypropylene, and ethylene copolymers. Olefin resins are mainly used. The laminate having the sealant layer formed thereon is used as a bag-shaped packaging container, or as a lid material of a cup-shaped or box-shaped packaging container made of plastic, paper, or the like. These packages need to have high sealing strength and excellent sealing properties, and also have excellent easy-opening properties (easy-opening properties) when the contents are used. In the case of a bag-shaped packaging container, the bag may be torn and opened, but in the case of a cup-shaped or box-shaped packaging container lid, the lid is often peeled off from the container body and opened. The material must be easy to peel from the container (easy peeling property).

One of the main methods for imparting easy peel properties to a sealant is to prepare a resin composition in which different kinds of resins are blended.
No., for example. However, a resin composition in which a styrene-based resin and an olefin-based resin are blended has a problem that the refractive index of the two is significantly different, so that even when processed into a film, the transparency is poor. When a sealant is used as a lid material of a container such as a cup, there is a demand that the contents of the container be seen clearly, but the low transparency of the sealant layer of the lid material has been an obstacle.

[0004] Further, when a sealant exhibiting easy-peeling properties is directly heat-sealed to an adherend such as a container as a sealant, the seal strength (peel strength) greatly changes depending on heat-sealing conditions such as temperature, pressure and time. In many cases, stable peel strength could not be obtained. In addition, although peeling occurs between the sealant material and the adherend, in a region having a high peeling strength, cohesive failure peeling often occurs, and there is a problem that the appearance of the peeling interface is not good.

As a means for solving these problems, a laminated film having a sealant layer and a release layer is provided, and the sealant layer is completely fused to an adherend and delaminated at the interface between the sealant layer and the release layer ( A delamination type easy peel) has been proposed.
No. 070 discloses a film comprising a heat-sealing sealing layer made of polyethylene as an outermost layer, and an easily breakable layer made of a blend of a styrene resin and an ethylene resin laminated thereon. . But,
This method has a layer made of a blend of a styrene-based resin and an ethylene-based resin, and is inferior in transparency.

[0006]

In such a situation,
An object of the present invention is to provide an easy-peeling property, an easy-opening property, and a peeling property for a styrene-based resin container, an ethylene-based resin container, a paper-made container laminated with an ethylene-based resin, and a propylene-based resin container. An object of the present invention is to provide a laminated film which is excellent in interface beauty and excellent in transparency. Another object of the present invention is to provide a lid member made of the laminated film and a container made of the laminated film.

[0007]

That is, the present invention relates to a sealant layer in which at least one surface layer has a thickness of 1 to 10 μm, a cohesion failure layer adjacent to the sealant layer and having a thickness of 1 to 10 μm, and a cohesion failure layer. A laminate film comprising at least three adjacent support layers, wherein the sealant layer is a layer containing a resin selected from styrene-based resins, ethylene-based resins, and propylene-based resins; A layer comprising a layer containing the following olefin-based resin or olefin-based resin composition (X); and the support layer comprising a layer containing the following olefin-based resin or the olefin-based resin composition (Y). It is. Olefin resin or olefin resin composition (X):
An olefin resin or an olefin resin composition containing the following components (A) and (B) and satisfying the following formula: K + L = 100 Formula 35 ≦ 0.2 × K + 0.8 × M ≦ 55 Formula ( In the formula, K is the compounding amount (% by weight) of the component (A), L is the compounding amount (% by weight) of the component (B), and M is the component (A) from the vinyl monomer in the following ethylene copolymer. The content (% by weight) of the derived repeating unit is shown.) Component (A) One or more vinyls selected from unsaturated carboxylic acids, unsaturated carboxylic esters, unsaturated carboxylic anhydrides, and vinyl acetate One type or a mixture of two or more types of ethylene-based copolymers composed of a repeating unit derived from a monomer and a repeating unit derived from ethylene Component (B) ethylene-based resin or propylene-based resin (only (Excluding the ethylene copolymer of the component (A).) Olefin resin or olefin resin composition (Y):
An olefinic resin which is an ethylene-based resin or a propylene-based resin (excluding the ethylene-based copolymer of the component (A)) and which contains at least 60% by weight of the same resin as the resin used in the component (B); Resin or olefin-based resin composition The present invention is also a lid material comprising the above-mentioned laminated film. Further, the present invention is a container comprising the above laminated film. Hereinafter, the present invention will be described in detail.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the laminated film of the present invention, at least one surface layer has a thickness of 1 to 10 μm, preferably 3 to 7 μm.
A laminated film comprising a sealant layer having a thickness of 1 μm, a cohesive failure layer having a thickness of 1 to 10 μm, preferably 3 to 7 μm adjacent to the sealant layer, and a support layer adjacent to the cohesive failure layer. When the thickness of the sealant layer and the cohesive failure layer is out of the range of the present invention, it is not preferable because good easy peelability is not exhibited.

[0009] The sealant layer in the present invention is a layer containing a kind of resin selected from styrene resin, ethylene resin and propylene resin. Examples of the styrene-based resin include polystyrene, rubber-modified polystyrene, styrene-butadiene block copolymer, and a mixture thereof. Among them, from the viewpoint of the transparency of the film, the weight average molecular weight is from 200,000 to 40,000.
A styrene-based resin or styrene-based resin composition containing 60 to 100% by weight of polystyrene and 0 to 40% by weight of rubber-modified polystyrene having an average gel particle diameter of 0.1 to 5 μm and a gel amount of 5 to 30% by weight Is preferred. Examples of the ethylene resin include polyethylene such as low-density polyethylene and high-density polyethylene; ethylene-butene-1
Copolymers, ethylene-based copolymers such as ethylene-α-olefin copolymers such as ethylene-hexene-1 copolymer, and mixtures thereof. Examples of the α-olefin of the ethylene-α-olefin copolymer include C 4 to C 1 such as butene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, and decene-1.
Α-olefin of 0. Examples of the propylene-based resin include propylene-based polymers such as polypropylene, propylene-α-olefin block copolymer, and propylene-α-olefin random copolymer, and mixtures thereof. As the α-olefin of the propylene-α-olefin block copolymer and the propylene-α-olefin random copolymer, for example, ethylene,
Α having 2 or 4 to 10 carbon atoms, such as butene-1 and octene-1
-Olefins.

When a sealant layer made of a styrene resin is used, a container made of a styrene resin is used. When a sealant layer made of an ethylene resin is used, a container made of an ethylene resin or paper laminated with an ethylene resin is used. In the case of a propylene-based resin sealant layer, the propylene-based resin
Each can be used.

The cohesive failure layer in the present invention comprises a layer containing the following olefin resin or olefin resin composition (X). Olefin resin or olefin resin composition (X):
An olefin resin or an olefin resin composition containing the following components (A) and (B) and satisfying the following formula: K + L = 100 Formula 35 ≦ 0.2 × K + 0.8 × M ≦ 55 Formula ( In the formula, K is the compounding amount (% by weight) of the component (A), L is the compounding amount (% by weight) of the component (B), and M is the component (A) from the vinyl monomer in the following ethylene copolymer. The content (% by weight) of the derived repeating unit is shown.) Component (A) One or more vinyls selected from unsaturated carboxylic acids, unsaturated carboxylic esters, unsaturated carboxylic anhydrides, and vinyl acetate One type of ethylene-based copolymer consisting of a repeating unit derived from a monomer (hereinafter, referred to as "vinyl monomer unit") and a repeating unit derived from ethylene (hereinafter, referred to as "ethylene unit"). Is a mixture of two or more types of component (B) ethylene-based resin or propylene-based resin (however, excluding the ethylene-based copolymer of component (A)), wherein two or more types of ethylene having different contents of vinyl monomer units When the copolymer is used as the component (A), the value of M is an average value of the weight ratio of each vinyl monomer unit. For example, an ethylene copolymer having a vinyl monomer unit content of M ₁ (% by weight) is converted to N ₁ (% by weight),
The value of M (% by weight) obtained by using a mixture of an ethylene copolymer having a vinyl monomer unit content of M ₂ (% by weight) and N ₂ (% by weight) as the component (A) is determined by the following equation. And _{M = M 1 × N 1/} 100 + M 2 × N 2/100

Here, when the blending amount of the above components (A) and (B) or the content of the vinyl monomer unit of the olefin resin or the olefin resin composition (X) is out of the range of the present invention, If the above formulas and the formulas are not satisfied, it is not preferable because easy peelability is not exhibited. Further, the cohesive failure layer preferably contains an olefin resin or an olefin resin composition satisfying the following formula, and the component (A) has a content of 40 to 100% by weight and the component (B) 0
It is preferable to include an olefin-based resin or an olefin-based resin composition containing up to 60% by weight. That is, the value of K is preferably 40 to 100% by weight, and the value of L is preferably 0 to 60% by weight. 38 ≦ 0.2 × K + 0.8 × M ≦ 52 Expression

Examples of the ethylene copolymer of component (A) include ethylene-unsaturated carboxylic acid copolymer, ethylene-unsaturated carboxylic acid ester copolymer, and ethylene-unsaturated carboxylic anhydride copolymer. , Ethylene-vinyl acetate copolymer, ethylene-unsaturated carboxylic acid ester-
Examples include vinyl acetate terpolymers, and multi-component copolymers composed of ethylene units and two or more kinds of unsaturated carboxylic acid ester units.

Examples of the unsaturated carboxylic acid include acrylic acid and methacrylic acid. Further, as the unsaturated carboxylic acid ester, for example, ethyl acrylate,
Methyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate,
-Ethylhexyl methacrylate, stearyl methacrylate, glycidyl methacrylate and the like. Examples of the unsaturated carboxylic anhydride include maleic anhydride. Preferred specific examples of component (A) include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer , Ethylene-ethyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl methacrylate-
Glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-
And maleic anhydride copolymer.

The content M of the vinyl monomer unit is 25
~ 50% by weight is preferred. Among the specific examples of the component (A), an ethylene-methyl methacrylate copolymer, an ethylene-vinyl acetate copolymer or a mixture thereof is preferable.
The component (A) is an ethylene-methyl methacrylate copolymer having a methyl methacrylate unit content of 25 to 50% by weight, an ethylene-vinyl acetate copolymer having a vinyl acetate unit content of 25 to 50% by weight, or That mixture is more preferred. Further, the binding mode of the vinyl monomer unit and the ethylene unit in the ethylene-based copolymer,
For example, random, block, and alternation are not limited at all.

Specific examples of the component (B) used in the present invention include polyethylene such as low-density polyethylene and high-density polyethylene; ethylene-butene-1 copolymer;
Ethylene-α-olefin copolymers such as hexene-1 copolymer; propylene-based polymers such as polypropylene, propylene-α-olefin block copolymer, propylene-α-olefin random copolymer, and mixtures thereof. Can be Here, as the α-olefin of the ethylene-α-olefin copolymer, for example, butene-1,
Hexene-1, 4-methylpentene-1, heptene-
Α having 4 to 10 carbon atoms, such as 1, octene-1 and decene-1
-Olefins. Examples of the α-olefin of the propylene-α-olefin block copolymer and the propylene-α-olefin random copolymer include, for example, ethylene, butene-1, and octene having 2 to 4 carbon atoms.
Α-olefin of 0.

The method of mixing the above-mentioned components (A) and (B) is not particularly limited, and the respective pellets are sufficiently mixed by dry blending, or they are melt-kneaded by an extruder and then re-formed into pellets. Any of granulated ones may be used.

The olefin resin or olefin resin composition (X) used in the present invention may contain, if necessary, a compatibilizer, a lubricant, an antiblocking agent, an antistatic agent, an antioxidant, a heat stabilizer, You may contain an ultraviolet absorber, an antibacterial agent, an antifogging agent, etc.

The support layer in the present invention is an ethylene-based resin or a propylene-based resin (however, excluding the ethylene-based copolymer of the component (A)) and the component (B).
It is composed of an olefin resin or an olefin resin composition (Y) containing at least 60% by weight of the same resin as the resin used in the above. That is, the component (B)
When an ethylene-based resin is used, at least 60% by weight of the same ethylene-based resin as the component (B) is used in the support layer. If the proportion is less than 60% by weight,
The interlayer adhesion strength between the cohesive failure layer and the support layer is insufficient, which is not preferable.

In the laminated film of the present invention for a container made of a styrene resin, the sealant layer has a weight average molecular weight of 200,000 to 400,000 polystyrene 60 to 100.
Weight%, average gel particle diameter 0.1-5 μm, gel amount 5
A styrene-based resin or a styrene-based resin composition containing 0 to 40% by weight of rubber-modified polystyrene having a content of methyl methacrylate unit of 25 to 50% by weight. An ethylene-methyl methacrylate copolymer, an ethylene-vinyl acetate copolymer having a vinyl acetate unit content of 25 to 50% by weight or a mixture thereof at 40 to 100% by weight, wherein the component (B) of the cohesive failure layer is polyethylene. And a laminated film comprising 60 to 0% by weight of an ethylene-α-olefin copolymer or a mixture thereof, and a support layer comprising polyethylene, an ethylene-α-olefin copolymer or a mixture thereof.

The method for obtaining the laminated film of the present invention is not particularly limited.
Conventional co-extrusion processing methods such as co-pressing T-die processing can be used. However, the laminated film of the present invention is co-extruded so that at least one surface layer is composed of a sealant layer, a cohesive failure layer adjacent to the sealant layer, and a support layer adjacent to the cohesive failure layer.

The thickness of the laminated film of the present invention is not particularly limited, but is preferably 20 to 100 μm.

The laminated film of the present invention is not particularly limited with respect to the sealant layer, the cohesion failure layer and other layers other than the support layer. It is necessary that the strength be equal to or higher than the adhesion strength between the fracture layer and the cohesive failure layer and the support layer.

The lid material of the present invention comprises the above laminated film. As a method for obtaining the lid material of the present invention, for example, a laminate formed by laminating a base material composed of plastic, aluminum foil or paper and the laminated film of the present invention, and then processing the laminate into a predetermined shape Method. Here, it is necessary to laminate the layer on the opposite side of the sealant layer and the substrate. In the case of laminating, it is preferable to apply a surface treatment such as a corona discharge treatment to the surface layer of the laminated film and the substrate of the present invention to be laminated, and to laminate the treated surfaces together. When the sealant layer side is heat-sealed to a container (substrate) corresponding to the above-described sealant material, the sealant layer and the adherend are completely fused, and the interlayer between the sealant layer and the cohesive failure layer, Peeling is caused by an appropriate force between the cohesive failure layer and the support layer in the fracture layer, and the container can be easily opened.

The lid of the present invention is used, for example, by filling the container body with the contents and then heat-sealing the lid to the container body.

The container of the present invention comprises the above laminated film. When the sealant layers are heat-sealed, the sealant layers are completely fused to each other, with an appropriate force between the sealant layer and the cohesive failure layer, in the cohesive failure layer, or between the cohesive failure layer and the support layer. Peeling occurs and the bag can be easily opened. In addition, the container of the present invention is, for example, a laminated film of the present invention laminated on paper or the like, and assembled into a container shape, or the laminated film of the present invention is laminated on at least a part of the inner surface of the container shape. What was done. The lid material in these cases is made of a resin selected from styrene resins, ethylene resins and propylene resins,
When the lid material and a portion of the container comprising the laminated film of the present invention are sealed, easy peelability is exhibited.

[0027]

As described above, according to the present invention, it is possible to provide a laminated film having an easy peel property and an easy open property, an excellent appearance of a peeling interface, and excellent transparency. Further, the present invention can provide a lid member made of a laminated film having the above excellent physical properties. Further, the present invention can provide a container comprising the laminated film having the excellent physical properties described above.

[0028]

Hereinafter, the present invention will be described based on examples.
The present invention is not limited to these examples.
In addition, among the evaluation items, the items other than the items described above were implemented as follows.

(1) Easy-peeling polyester single-layer film (manufactured by Toyobo Co., Ltd., trade name “Toyobo Ester E5100”, thickness 12 μm, width 50)
0 mm) and a corona-treated surface of the obtained film were dry-laminated. Dry lamination was performed using a tabletop test coater manufactured by Yasui Seiki Co., Ltd., using an aromatic ester anchor coating agent (base agent, Takeda Pharmaceutical Co., Ltd., trade name "Takelac A310", curing agent, Takeda Pharmaceutical Co., Ltd.) , Trade name "Takenate A3", and ethyl acetate
2% by weight: 1% by weight: 32% by weight and mixed well) were applied to the base material at an application amount of 2 g / m ² at a temperature of 40 ° C. and a pressure of 3 kg / cm ² . , And then heat-aged in a dryer at 40 ° C for 48 hours to obtain a laminated film. The sealant layer side of the obtained laminated film is brought into close contact with the adherend, and the pressure is 3 kg /
Heat sealing was performed under the conditions of cm ² , time 1 second, width 10 mm, and temperature shown in Table 1. As an adherend, rubber-modified polystyrene (“Sumibright E580” manufactured by Sumitomo Chemical Co., Ltd.) was used and V65 manufactured by Tanabe Plastic Machinery Co., Ltd.
A sheet having a thickness of 0.6 mm by a -1000 sheet extruder was used. Heat sealed sample 1
The sheet was cut into a width of 5 mm, and the peel strength was measured at 180 ° peeling at a pulling speed of 300 mm / min using an automatic strain type tensile tester manufactured by Toyo Seiki Co., Ltd. When the peel strength is less than 300 g / 15 mm width, the practical sealing property is poor, and when the peel strength exceeds 1500 g / 15 mm width, the easy peel property is poor. Peel strength stability
The difference between the maximum value and the minimum value at each heat sealing temperature was determined. It can be said that the smaller the value, the more stable the peel strength.

(2) State of Heat Seal Edge Film Remaining and Peeled Surface When peeled in the above evaluation, it was visually observed whether the film was cut at the heat seal edge or no film residue occurred. Further, the state of the peeled surface was observed. (3) Transparency of film The haze value of the film was measured based on JIS K7105.

Example 1 The resin constituting the sealant layer was polystyrene (weight average molecular weight 21) obtained by continuous bulk polymerization.
10,000) pellets. In the olefin-based resin composition (X) constituting the cohesion failure layer, as the component (A), an ethylene-methyl methacrylate copolymer resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: Acrif WM403, containing methyl methacrylate unit) 60% by weight of pellets having an amount of 38% by weight) and low-density polyethylene (melt flow rate: 2.0 g / 10 minutes, density: 0.923 g / c) obtained by high-pressure ion polymerization as component (B).
m ³ ) 40% by weight of pellets were mixed and sufficiently mixed. In the olefin-based resin composition (Y) constituting the support layer, low-density polyethylene (melt flow rate: 2.0 g / 10 min, density: 0.1 g) obtained by the same high-pressure ionic polymerization method as the component (B). 923 g / c
100% by weight of m ³ ) pellets were used. Using the above materials, a cast film forming apparatus manufactured by Modern Machinery Co., Ltd. (three types and three layers co-pressing T-die (width: 600 mm, extruder A:
40mmφ, Extruder B: 50mmφ, Extruder C: 40m
mφ)), the olefin-based resin composition (X) was extruded at a resin temperature of 21 ° C. using an extruder B at a resin temperature of 240 ° C. and an extrusion rate of 7 kg / hour.
Extruder A / Extruder B / Extruder The olefin-based resin composition (Y) was extruded at a resin temperature of 230 ° C. and an extrusion rate of 23 kg / hour at 0 ° C. and an extrusion rate of 5 kg / hour. Extrude so as to be laminated in the order of C, take-up speed 2
A three-layer laminated film was processed under the conditions of 6 m / min and a cooling roll temperature of 20 ° C., and the layer side of the film composed of the olefin resin composition (Y) was further subjected to a wetting tension of 45 dyne / cm.
Corona discharge treatment was performed so that The thickness of the sealant layer of the obtained film is 7 μm, and the thickness of the cohesive failure layer is 5 μm.
m, and the overall thickness was 35 μm. Table 1 shows the results.

Example 2 In the olefin resin composition (X) constituting the cohesion failure layer, as the component (A), an ethylene-methyl methacrylate copolymer resin (manufactured by Sumitomo Chemical Co., Ltd., trade name ACLIFT WM403) And 80% by weight of pellets containing methyl methacrylate units (content: 38% by weight), and low-density polyethylene (melt flow rate: 2.0 g / 1) obtained by a high-pressure ion polymerization method as component (B).
The same procedure as in Example 1 was carried out except that 20% by weight of pellets having 0 minutes and a density of 0.923 g / cm ³ ) were mixed and sufficiently mixed. The thickness of the sealant layer of the obtained film was 7 μm, the thickness of the cohesive failure layer was 5 μm, and the overall thickness was 35 μm. Table 1 shows the results.

Example 3 In the olefin resin composition (X) constituting the cohesion failure layer, as the component (A), an ethylene-methyl methacrylate copolymer resin (Aclift WM403, manufactured by Sumitomo Chemical Co., Ltd.) , Methylmethacrylate unit content: 38% by weight), except that pellets of 100% by weight were used. The thickness of the sealant layer of the obtained film is 7 μm, and the thickness of the cohesive failure layer is 5 μm.
m, and the overall thickness was 35 μm. Table 1 shows the results.

Comparative Example 1 The extruder A / extruder B / extruder C was extruded at a rate of 7
The operation was performed in the same manner as in Example 1 except that kg / hour, 22 kg / hour, and 22 kg / hour were used. The thickness of the sealant layer of the obtained film is 7 μm, and the thickness of the cohesive failure layer is 20 μm.
m, and the overall thickness was 48 μm. Table 1 shows the results.

Comparative Example 2 The extruder A / extruder B / extruder C was extruded at a rate of 7
The operation was performed in the same manner as in Example 2 except that kg / hour, 22 kg / hour, and 22 kg / hour were used. The thickness of the sealant layer of the obtained film is 7 μm, and the thickness of the cohesive failure layer is 20 μm.
m, and the overall thickness was 48 μm. Table 1 shows the results.

Comparative Example 3 As a resin constituting the sealant layer, polystyrene (weight average molecular weight of 29) obtained by continuous bulk polymerization was used.
10,000) pellets. As the cohesive failure layer and the support layer, rubber-modified polystyrene (content of soft component particles: 20.8% by weight, melt flow rate: 3.2 g / 10 minutes) obtained by continuous bulk polymerization, 58% by weight of pellets, Ethylene-methyl methacrylate copolymer resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: ACLIFT WM403, content of methyl methacrylate unit: 38% by weight, SP
Value: 8.50), an ethylene-hexene-1 copolymer obtained by a high-pressure ionic polymerization method (melt flow rate: 0.8 g / 10 min, density: 0.1%).
925 g / cm ³ ) pellets 15% by weight, styrene-
Pellets of isoprene block copolymer rubber hydrogenated product (Septon 2104, manufactured by Kuraray Co., Ltd.) were sufficiently mixed at a ratio of 4% by weight, and the resulting mixture was mixed with Tanabe Plastic Machinery Co., Ltd.
A pellet (styrene-based resin composition) obtained by granulating at a temperature of 210 ° C. using a 0 mmφ single screw extruder was used.
Using the above materials, a cast film forming device manufactured by Modern Machinery Co., Ltd. (3 types, 3 layers co-pressing T-die (width: 600 mm,
Extruder A: 40 mmφ, extruder B: 50 mmφ, extruder C: 40 mmφ)), the above styrene resin composition was extruded by extruders B and C at a resin temperature of 240 ° C. and an output of 10
The extruder was extruded under the conditions of kg / hour and 8 kg / hour, and the polystyrene was extruded with an extruder A at a resin temperature of 240 ° C. and an output of 4 kg.
Extruding under the condition of / h, a take-off speed of 12.4 m / min,
The two-layer laminated film was processed under the condition of a cooling roll temperature of 40 ° C., and the layer side made of the styrene-based resin composition was subjected to corona discharge treatment so as to have a wetting tension of 45 dyne / cm. The thickness of the sealant layer of the obtained film was 8 μm, and the overall thickness was 44 μm. Table 1 shows the results
Shown in

[0037]

Table 1----------------------------------------------------------------------------------- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Thickness of sealant layer μm 7 7 7 7 7 8 Thickness of cohesive failure layer μm 5 5 5 20 20 36 Easy peelability Peel strength kg / 15mm width Heat seal temperature 150 ℃ kg / 15mm width 0.80 0.95 0.82 1.62 2.06 0.57 160 ℃ kg / 15mm width 0.78 0.92 0.82 2.11 2.50 0.60 170 ℃ kg / 15mm width 1.02 0.93 0.85 1.94 2.70 0.63 180 ° C kg / 15mm width 1.12 0.98 0.86 2.03 1.24 0.67 190 ° C kg / 15mm width 1.06 0.94 0.80 1.98 1.14 0.81 Difference between maximum and minimum 0.34 0.06 0.06 0.49 1.56 0.24 Seal edge film remaining No No No Yes Existence Exfoliation surface state ○ ○ ○ × × ○ Film transparency Haze% 3.0 2.8 1.9 6.1 6.3 50.0 −−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−

Continuation of front page (56) References JP-A-9-124070 (JP, A) JP-A-6-297655 (JP, A) JP-A-5-199305 (JP, A) JP-A-5-32288 (JP JP-A-8-323933 (JP, A) JP-A-8-267634 (JP, A) JP-A-10-193531 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B32B 1/00-35/00

Claims (9)

(57) [Claims] (1) at least one surface layer has a thickness of 1 to 10 μm;
A sealant layer having a thickness of 1 to 1 adjacent to the sealant layer.
A laminated film comprising at least three layers of a cohesion failure layer having a thickness of 10 μm and a support layer adjacent to the cohesion failure layer, wherein the sealant layer is selected from a styrene resin, an ethylene resin, and a propylene resin. The cohesion failure layer is composed of a layer containing the following olefin resin or olefin resin composition (X), and the support layer is composed of the following olefin resin or olefin resin composition (Y). A laminated film comprising a layer containing: Olefin resin or olefin resin composition (X):
An olefin resin or an olefin resin composition containing the following components (A) and (B) and satisfying the following formula: K + L = 100 Formula 35 ≦ 0.2 × K + 0.8 × M ≦ 55 Formula ( In the formula, K is the compounding amount (% by weight) of the component (A), L is the compounding amount (% by weight) of the component (B), and M is the component (A) from the vinyl monomer in the following ethylene copolymer. The content (% by weight) of the derived repeating unit is shown.) Component (A) One or more vinyls selected from unsaturated carboxylic acids, unsaturated carboxylic esters, unsaturated carboxylic anhydrides, and vinyl acetate One type or a mixture of two or more types of ethylene-based copolymers composed of a repeating unit derived from a monomer and a repeating unit derived from ethylene Component (B) ethylene-based resin or propylene-based resin (only (Excluding the ethylene copolymer of the component (A).) Olefin resin or olefin resin composition (Y):
An olefinic resin which is an ethylene-based resin or a propylene-based resin (excluding the ethylene-based copolymer of the component (A)) and which contains at least 60% by weight of the same resin as the resin used in the component (B); Resin or olefin resin composition 2. The value of K is 40-100, and the value of L is 0-60.
The laminated film according to claim 1, wherein the values of and M are 25 to 50. 3. The laminated film according to claim 1, wherein the component (A) is an ethylene-unsaturated carboxylic acid ester copolymer. 4. The laminated film according to claim 1, wherein the component (A) is an ethylene-methyl methacrylate copolymer, an ethylene-vinyl acetate copolymer or a mixture thereof. 5. An ethylene-methyl methacrylate copolymer in which the component (A) has a content of a repeating unit derived from methyl methacrylate of 25 to 50% by weight, and a content of a repeating unit derived from vinyl acetate of 25 to 50% by weight. The laminated film according to claim 1, which is 50% by weight of an ethylene-vinyl acetate copolymer or a mixture thereof. 6. The sealant layer has a weight average molecular weight of 200,000 or more.
A styrene-based resin or styrene-based resin composition containing 60 to 100% by weight of polystyrene of 400,000, and 0 to 40% by weight of rubber-modified polystyrene having an average gel particle diameter of 0.1 to 5 μm and a gel amount of 5 to 30% by weight The laminated film according to claim 1, comprising a product. 7. The sealant layer has a weight average molecular weight of 200,000 or more.
A styrene-based resin or styrene-based resin composition containing 60 to 100% by weight of polystyrene of 400,000, and 0 to 40% by weight of rubber-modified polystyrene having an average gel particle diameter of 0.1 to 5 μm and a gel amount of 5 to 30% by weight Ethylene-methyl methacrylate copolymer wherein the component (A) of the cohesive failure layer is 25 to 50% by weight of the repeating unit derived from methyl methacrylate, the content of the repeating unit derived from vinyl acetate 25 to 50% by weight of an ethylene-vinyl acetate copolymer or a mixture thereof 40
-100% by weight, the component (B) of the cohesion failure layer is made of polyethylene, an ethylene-α-olefin copolymer or a mixture thereof at 60 to 0% by weight, and the support layer is made of polyethylene, ethylene-α-olefin copolymer. 2. The laminated film according to claim 1, comprising a coalescence or a mixture thereof. 8. A lid comprising the laminated film according to any one of claims 1 to 7. 9. A container comprising the laminated film according to claim 1.