JP2001277408A - Resin laminated film excellent in stiffness strength and impact resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin laminated film excellent in stiffness strength and impact resistance. SOLUTION: In the resin laminated film constituted of a laminate consisting of at least three or more resin layers, the laminate has a sandwich structure wherein three adjacent layers consist of one intermediate layer (b) and two surface material layers (a), (c) holding the intermediate layer (b) between them and the elastic modulus of the same or different resins in kind used in the surface material layers (a), (c) holding the intermediate layer (b) between them is made larger than that of the resin used in the intermediate layer (b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin laminate comprising at least three resin layers, which is useful as a soft wrapping material for, for example, standing pouches and inner containers of back-in boxes. The present invention relates to a film, and more particularly to a resin laminated film having excellent rigidity and impact resistance, and excellent waist strength and impact resistance.

[0002]

2. Description of the Related Art Hitherto, the stiffness of a film has been an extremely important factor in terms of suitability for a packaging machine and maintenance of a packaging form at a store.

[0003] Generally, in the case of strengthening the stiffness, in the case of a single body, the thickness is increased or stretched.

Further, in the case of polyethylene, it is used in place of polyethylene having high density.

On the other hand, when laminating, measures such as lamination with a stretched film (substrate) of nylon, polyester, polypropylene or the like are taken.

In some cases, paper is laminated to increase waist strength.

[0007]

However, it is not desirable to increase the thickness because the cost increases accordingly.

[0008] Also, in the case of stretching,
It is limited by the physical properties of the resin.

In the case of polyethylene, the higher the density, the lower the impact resistance, and it is difficult to balance the stiffness and the impact resistance.

Further, even in the case of bonding to a base material, if the required stiffness becomes high, the stiffness of the base material is insufficient because the stiffness of the resin layer itself is required. Become.

An object of the present invention is to provide a laminated resin film having high waist strength, excellent shock resistance, and excellent waist strength and impact resistance by forming a sandwich structure with a resin layer. .

[0012]

In order to achieve the above object, according to the first aspect of the present invention, in a resin laminated film composed of a laminate composed of at least three resin layers, Three adjacent layers among them have a sandwich structure composed of one intermediate layer and two face material layers sandwiching the intermediate layer, and the same or different resins used for the face material layers sandwiching the intermediate layer Is larger than the elastic modulus of the resin used for the intermediate layer.

Further, in the invention corresponding to claim 2, in a resin laminated film composed of a laminated body composed of at least four resin layers, the laminated body has at least four or more adjacent layers. It has a sandwich structure composed of two or more intermediate layers and two face material layers sandwiching the intermediate layer, and determines the elastic modulus of the same or different resin used for the face material layers sandwiching the intermediate layer by using the intermediate layer. Is larger than the modulus of elasticity of the resin used for the resin.

On the other hand, in the invention according to claim 3, in a resin laminated film composed of a laminated body composed of at least three resin layers, the laminated body is such that adjacent three layers are one intermediate layer. And two face material layers sandwiching the intermediate layer, and have a modulus of elasticity (E) of the same or different resin used for the face material layers sandwiching the intermediate layer.
1, E3) is larger than the elastic modulus (E2) of the resin used for the intermediate layer by an elastic modulus ratio (E1 / E2, E3 / E2).
Is 1.2 times larger.

Further, in the invention corresponding to claim 4, in a resin laminated film composed of a laminated body composed of at least four or more resin layers, the laminated body has at least four or more adjacent layers. It has a sandwich structure composed of two or more intermediate layers and two face material layers sandwiching the intermediate layer, and the elastic modulus (E1, E3) of the same or different resin used for the face material layers sandwiching the intermediate layer ) Is smaller than the average elastic modulus (E2) of the resin used for each intermediate layer.
The elastic modulus ratio (E1 / E2, E3 / E2) is increased by 1.2 times or more.

Furthermore, in the invention corresponding to claim 5, in a resin laminated film composed of a laminated body composed of at least four or more resin layers, the laminated body has at least four or more adjacent layers. It has a sandwich structure consisting of two or more intermediate layers and two face material layers sandwiching the intermediate layer, and the elastic modulus of the same or different resin used for the face material layers sandwiching the intermediate layer is determined by The elastic modulus of the resin used for the intermediate layer is larger than the largest elastic modulus.

According to a sixth aspect of the present invention, there is provided a resin laminated film having excellent waist strength and impact resistance according to the first or third aspect of the present invention, wherein the resin used for the intermediate layer is The film thickness is larger than the film thickness of the resin layer of the face material layer.

According to a seventh aspect of the present invention, there is provided a resin laminated film according to any one of the second, fourth, and fifth aspects of the invention, which is excellent in waist strength and impact resistance. The total thickness of the resin used for each intermediate layer is made larger than the thickness of the resin layer of the face material layer.

Further, according to the invention according to claim 8, in the resin laminated film having excellent waist strength and impact resistance according to the invention according to any one of claims 1 to 7, the face material layer is At least one of the layers used is a metal layer such as aluminum or stainless steel.

According to a ninth aspect of the present invention, there is provided a resin laminated film excellent in waist strength and impact resistance according to the first aspect of the invention.
A surface layer composed of a resin layer or a metal layer is laminated on one or both sides of the outer surface of the laminate forming the sandwich structure.

Further, in the invention corresponding to claim 10,
In the resin laminated film excellent in waist strength and impact resistance according to any one of claims 1 to 9, the resin used for each layer of the laminated body forming the sandwich structure is respectively The same type of resin that is heat-sealed.

On the other hand, in the invention corresponding to claim 11, in the resin laminated film excellent in waist strength and impact resistance according to the invention according to claim 10, the same kind of resin is a polyethylene resin, The density of the resin used for the layer is set higher than the density of the resin used for the intermediate layer.

According to a twelfth aspect of the present invention, in the resin laminated film according to the tenth aspect of the present invention, which is excellent in waist strength and impact resistance, the same kind of resin is a polyethylene-based resin. The density of the resin used for the layers (D1, D3) is greater than the density of the resin used for the intermediate layer (D2) or the average density of the resin used for each intermediate layer (D2). , Density difference (D1-D2,
D3-D2) is increased by 0.015 or more.

Further, in the invention according to claim 13,
In the resin laminated film having excellent waist strength and impact resistance according to the invention according to claim 10, the same kind of resin is a polyolefin resin, and the resin used for the face material layer is a polypropylene resin, an intermediate resin. A resin laminated film excellent in waist strength and impact resistance, characterized in that the resin used for the layer is a linear polyethylene resin.

According to a fourteenth aspect of the present invention, there is provided a resin laminated film excellent in waist strength and impact resistance according to any one of the first to ninth aspects, wherein a sandwich structure is formed. The resin used for each layer of the laminate to be used is a different resin, and between each layer,
They are bonded via an adhesive or an adhesive resin.

Accordingly, in the resin laminated film of the present invention having excellent waist strength and impact resistance, at least three or more layers are required.
Or by forming a sandwich structure with at least four or more resin layers, high waist strength, excellent impact resistance, it is possible to obtain a resin laminated film excellent in waist strength and impact resistance, It is possible to obtain a resin laminated film having excellent waist strength and impact resistance, which have conflicting properties of impact strength and rigidity.

Further, as an intermediate layer sandwiched between two face material layers in the laminate, two or more intermediate layers are laminated to form an adhesive or an adhesive resin between each layer of the laminate. In the case of bonding via a resin, a resin laminated film which is excellent in waist strength and impact resistance capable of performing good bonding can be obtained.

That is, the resin laminated film is
When one intermediate layer is sandwiched between two facing material layers to form an adhesive laminate, the compatibility between one facing material layer and the intermediate layer is good, but the other facing material layer has an intermediate property. When the compatibility with the layer is not good, the intermediate layer has a two-layer structure composed of two intermediate layers having good compatibility with each other, and one of the intermediate layers has a good adhesion with one face material layer. Good compatibility and good compatibility between the other intermediate layer and the other face material layer, so that the two intermediate layers are sandwiched between the two face material layers, Adhesive lamination can be performed.

Therefore, by using the resin laminated film having excellent waist strength and impact resistance of the present invention, since it has both waist and impact strength, a film for a standing pouch and a film for a bag in a back-in-box. This makes it possible to develop various packaging films such as heavy bag packaging films and to reduce the amount of resin used in the films.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a sandwich structure is basically defined as one intermediate layer having another type or another function, or two or more intermediate layers, between two face material layers. It is formed by bonding and laminating an intermediate layer.

Here, the face material layer is a material layer that is thinner and stronger in strength than the intermediate layer, and the intermediate layer is a material layer that is thicker and stronger in strength than the face material layer. It is defined as a layer, and has a resin laminated film structure that can be expected to have new functions with excellent waist strength and impact resistance as a whole.

Hereinafter, embodiments of the present invention based on the above-described concept will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a cross-sectional view showing a configuration example of a resin laminated film having excellent waist strength and impact resistance according to the present embodiment.

That is, the resin laminated film having excellent waist strength and impact resistance according to the present embodiment is a resin laminated film composed of a laminate composed of at least three or more resin layers as shown in FIG. The laminated body has a structure in which three adjacent layers among them are bonded and laminated with one intermediate layer b having another type or another function interposed between two face material layers a and c. .

(Second Embodiment) FIG. 2 is a sectional view showing an example of the configuration of a resin laminated film having excellent waist strength and impact resistance according to the present embodiment. The reference numerals are attached and shown.

That is, the resin laminated film having excellent waist strength and impact resistance according to the present embodiment is a resin laminated film composed of a laminate composed of at least four or more resin layers as shown in FIG. In the laminate, four or more adjacent layers (four layers in the figure) have two or more intermediate layers having other types or other functions between the two face material layers a and c. (In the figure, two intermediate layers) b1 and b2 are sandwiched and bonded and laminated.

The present laminated structure is particularly lightweight and highly rigid due to its combined effect, and thus can be widely used in fields such as aircraft, ships, automobiles, tanks, and construction.

In such a field, as a material used for the sandwich structure, an aluminum alloy is most commonly used for the face material layers a and c.

For example, metal materials such as steel plates, titanium alloys and magnesium alloys, non-metallic materials such as woody materials and inorganic materials, and reinforced plastics can be used.

As the intermediate layer b or b1, b2 (core material), for example, an aluminum alloy, stainless steel, or titanium alloy is used in the form of a honeycomb, or porous ceramics, foam glass, wood, paper, or the like is used.

The most frequently used core materials are plastics which increase the bulk, such as phenolic resin, epoxy resin, polyurethane, polystyrene, polyvinyl chloride, and acrylic resin.

In the plastic film field, particularly in the field of packaging materials, attempts have been made to improve waist strength and impact resistance by laminating various layers. However, improvement utilizing composite effects such as sandwich structures has not been attempted so far. Not done.

In this embodiment, the face layers a and c are made of the same or different resins having a higher elastic modulus than the intermediate layer b or b1 and b2, and the laminated film is provided with a stiffness. Alternatively, by providing a single-layer or multilayer resin layer having impact strength on b1 and b2, the laminated film is given impact strength.

The elastic modulus defined in the present invention only needs to indicate the rigidity of a film or a sheet, and may be either a tensile elastic modulus or a flexural elastic modulus.

There are four types of elastic modulus, Young's modulus, Poisson's ratio, bulk elasticity, and rigidity. Here, the Young's modulus is defined.
Any of the rigidities may be defined.

The stiffness, such as loop stiffness, may be used as long as it is a scale indicating rigidity, instead of the elastic modulus.

The resin formed on the face material layers a and c has a high elastic modulus, rigidity and waist strength, and is a resin layer formed to satisfy the target waist strength of the film. Any resin that satisfies the waist strength may be used. From the theory of the sandwich structure, the resin layer formed on the face material layers a and c has a higher elastic modulus than the resin layer formed on the intermediate layer b. Is preferred.

Generally, any resin used for the film, such as polyethylene, polypropylene, nylon, polyvinyl chloride, polyester, polyvinyl alcohol, etc. may be used, and there is no particular limitation on the type of resin.

The face layer may not be a resin layer, but may be a metal layer such as an aluminum foil or a stainless steel foil, or a vapor-deposited layer such as a ceramic vapor-deposited film.
It is not necessary to limit the material of the.

Since the metal layer is generally more rigid than the resin layer, the rigidity of the sandwich effect of the present invention can be further increased, which is preferable.

That is, the resin layers formed on the face material layers a and c have higher elastic modulus, rigidity and waist strength than the resin layers formed on the intermediate layer b or b1 and b2. When a resin is used, the rigidity of the film is increased and a stiff film can be obtained as compared with the usual laminating method and when the resin is superposed when the elastic modulus is large.

The strength ratio such as the elastic modulus and stiffness used for the face material layers a and c with respect to the intermediate layer b or b1 and b2 may be large, but is preferably 1.2 times or more, more preferably 2 times or more. It is desirable that the size be twice or more.

Here, when the intermediate layers are two or more intermediate layers such as b1 and b2, the respective intermediate layers b1 and b2
It is desirable to make the elastic modulus ratio 1.2 times or more larger than the average elastic modulus of the resin used for the above.

When the intermediate layers are two or more intermediate layers such as b1 and b2, the highest elastic modulus among the elastic moduli of the resins used for the respective intermediate layers b1 and b2. It is desirable to make it larger.

The resin formed on the intermediate layer b or b1, b2 has a high impact strength and is a resin layer formed to satisfy the required quality of the target impact strength of the film.
Any resin may be used as long as the resin satisfies the target impact strength of the film, and it is not particularly necessary to limit the type of resin from the sandwich configuration of the present invention.

When the intermediate layer is composed of two or more intermediate layers such as b1 and b2, a layer colored for shading is laminated, a recycled material is laminated, or a cheap material is laminated. May be.

At this time, as the elastic modulus of the laminated material, an average value obtained by dividing the sum of the elastic modulus of the constituent materials × the film thickness by the film thickness of the intermediate layer may be used as a representative value. What is necessary is just to be smaller than the elastic modulus of the layers a and c.

Preferably, the largest elastic modulus among the elastic moduli of the resin used for the intermediate layer is smaller than the elastic moduli of the face material layers a and c.

In the present embodiment, the film thickness of the laminated film is such that the thickness of the resin used for the three adjacent intermediate layers b or b1 and b2 is smaller than the thickness of the face material layer a sandwiching the intermediate layer b or b1 and b2. , C is preferably larger than the thickness of each resin layer from the viewpoint of increasing the impact strength of the laminated film.

That is, by increasing the thickness of the intermediate layers b or b1 and b2 to be laminated to increase the impact strength,
Impact strength increases.

In the present invention, a sandwich structure can be formed only with a polyolefin resin.
Further, by forming at least one of the face material layers and the intermediate layer with a polyolefin resin, the polyolefin resin and the heat seal layer (sealant) can be used. When forming into a shape, a bag can be prepared by heat-sealing the heat-seal layer with the heat-seal layer as the inner surface side.

Examples of the polyolefin resin include polyethylene, polypropylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ionomer, blends thereof, and modified resins obtained by modifying these.

Examples of the polyethylene resin include high-density polyethylene (HDPE) and low-density polyethylene (L
DPE) linear low density polyethylene (LLDPE) and the like are not particularly limited.

Since the impact strength or elastic modulus of the resin, that is, the waist strength and the rigidity of the polyethylene resin greatly differ depending on the density of the resin, the resin laminate of the present invention having excellent waist strength and impact resistance only by the polyethylene laminate is used. In order to form a film, it is sufficient that the density is higher than the intermediate layer b or b1, b2 which is the layer between which the facing material layers a, c are sandwiched. It is only necessary to provide a density difference of.

Specifically, a high-density polyethylene having rigidity and a tendency to have a low impact strength is sandwiched between a polyethylene having a high impact strength and a low-density tending to be soft, and the structure of the present invention is simply formed. The difference in density between high-density polyethylene and low-density polyethylene depends on the required physical properties of the film. In some cases, a small difference in density is sufficient, but it is preferably 0.015 or more.

As the polypropylene-based resin,
For example, homopolypropylene, copolymerized polypropylene with ethylene and the like are not particularly limited, but any polypropylene having an elastic modulus greater than the polyethylene of the intermediate layer b to be sandwiched may be used.

Further, the sandwich structure of the present embodiment may be formed only with a polypropylene-based resin.
For example, homopolypropylene and polypropylene having high impact strength include, for example, block copolymerized polypropylene. In order to form the configuration of the present embodiment using only polypropylene, a configuration in which block polypropylene is sandwiched between homopolypropylenes is considered.

When the resins forming the sandwich structure are different resins, and the layers are not completely bonded, the resin laminated film of the present invention having excellent rigidity and impact strength is difficult to obtain. It is necessary to completely bond the respective layers via an adhesive, an adhesive, or an adhesive resin.

In order to impart gas barrier properties, light shielding properties, heat sealing properties, non-adsorption properties, etc. to the resin laminated film of this embodiment having excellent waist strength and impact strength, a laminated structure having a sandwich structure is provided. A film having a function can be laminated as a surface layer on one or both outer surfaces of the body.

By laminating in this manner, the function of the film is enhanced, and the application of the film is expanded.

The film having the function of laminating is
Elastic modulus, compared to the resin layer that constitutes the sandwich structure,
There are no particular limiting factors such as film thickness.

For example, films such as polyethylene, polypropylene, nylon, polyvinyl chloride, polyester, and polyvinyl alcohol which are generally used for films, metal layers such as aluminum foil and stainless steel foil, and vapor deposition layers such as ceramic vapor deposition films may be used. It is not particularly necessary to limit the material.

The surface layer may have a multilayer structure if necessary.

Next, in the resin laminated film having excellent waist strength and impact resistance according to the present embodiment configured as described above, a sandwich structure is formed by three resin layers or four resin layers. By doing so, it is possible to obtain a resin laminated film having high waist strength and excellent impact resistance, and excellent waist strength and impact resistance.

As a result, it is possible to obtain a resin laminated film which has both the opposite properties of impact strength and rigidity, and has excellent waist strength and impact resistance.

Further, the two face material layers a,
c, two or more intermediate layers b1, b
By laminating the two layers, when bonding between the layers of the laminate through an adhesive or an adhesive resin, the waist strength and the impact resistance, which enable good bonding, can be achieved. An excellent resin laminated film can be obtained.

That is, the resin laminated film is
When a single intermediate layer b is sandwiched between two face material layers a and c to form an adhesive laminate, the compatibility between the face material layer a and the intermediate layer b is good. When the adhesive compatibility between c and the intermediate layer b is not good, the intermediate layer has a two-layer structure composed of intermediate layers b1 and b2 having good adhesive compatibility with each other, and the intermediate layer b1 and the face material layer a Adhesive compatibility is good,
In addition, the intermediate layer b2 has good adhesion compatibility with the face material layer c, so that the two intermediate layers b1 and b2 are sandwiched between the two face material layers a and c, and the adhesive layer is satisfactorily laminated. can do.

As described above, in the resin laminated film having excellent waist strength and impact resistance according to the present embodiment, 2
Three resin layers composed of one face material layer a, c and one intermediate layer b, or two face material layers a, c and two intermediate layers b1,
Since the sandwich structure is formed by four resin layers consisting of b2 and b2, it is possible to obtain a resin laminated film having high waist strength, and excellent waist strength and excellent impact resistance. It becomes possible.

Further, as the intermediate layer sandwiched between the two face material layers in the laminate, two or more intermediate layers b1 and b2 are laminated, so that each layer of the laminate is bonded with an adhesive. Alternatively, in the case of bonding via an adhesive resin, it is possible to obtain a resin laminated film excellent in waist strength and impact resistance capable of performing good bonding.

Therefore, by using the resin laminated film having excellent waist strength and impact resistance of the configuration of the present embodiment,
Because it has both waist and impact strength, it can be applied to various packaging films such as films for standing pouches, films for back-in-box inner bags, films for heavy bag packaging, etc., and reduces the amount of resin used for films. It becomes possible to plan.

[0081]

Next, specific examples of the present invention will be described in detail.

[Example 1] Linear low density polyethylene A
(MI = 4, density = 0.945, tensile modulus = 388M
Pa) resin as face material layers a and c, linear low density polyethylene B (MI = 4, density = 0.905, tensile modulus =
108 MPa) as the intermediate layer b, and the face material layers a and c
Both have a thickness of 20 μm, an intermediate layer b having a thickness of 60 m and a thickness of 100 μ
An m-sandwich film was extruded and formed at an extrusion temperature of 240 ° C.

The loop stiffness of the laminated film
The impact strength was measured.

For the loop stiffness, a loop was formed from a strip-shaped sample having a width of 25 mm and a length of 12 cm, and the loop was crushed at a crushing distance of 20 mm and a compression speed of 3.5 mm / sec, and the repulsive force of the loop was measured.

The higher the value, the higher the waist strength.

The impact strength was 13 mm in diameter at -10 ° C.
Drop the weight of 6.5mm in weight from 1.3m height,
The maximum load and crack generation energy were measured. The higher the value, the greater the impact strength.

The results are shown in Table 1 below.

As compared with the film of Comparative Example 1 having a different structure, both the loop stiffness and the impact strength were higher.

Comparative Example 1 Using the same resin as in Example 1,
Instead of forming a film having a sandwich structure, a film having a total thickness of 100 μm of a surface layer linear low-density polyethylene A having a two-layer structure of 40 μm and a rear layer linear low-density polyethylene B having a thickness of 60 μm was extruded and formed at an extrusion temperature of 240 ° C.

The film was measured for loop stiffness and impact strength.

The results are shown in Table 1 below.

As compared with the film of Example 1 having a different structure, both the loop stiffness and the impact strength showed lower values.

[Example 2] Linear low density polyethylene A
(MI = 4, density = 0.945, tensile modulus = 388M
Pa) resin as face material layer a, linear low density polyethylene B (MI = 4, density = 0.905, tensile modulus = 10)
8 MPa) resin as the intermediate layer b, linear low density polyethylene C (MI = 4, density = 0.920, tensile modulus =
139 MPa) was used as the back layer of the face material layer c, and a film having a thickness of 100 μm sandwiched between the face material layers a and c and the intermediate layer b having a thickness of 60 μm was extruded and formed at an extrusion temperature of 240 ° C. .

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared to the film of Comparative Example 2 having a different structure, both the loop stiffness and the impact strength were higher.

Comparative Example 2 Using the same resin as in Example 2,
By changing the order of the lamination structure, the linear low-density polyethylene A20
A film having a total thickness of 100 μm having a three-layer structure of μm / linear low-density polyethylene C 20 μm / linear low-density polyethylene B 60 μm was extruded and formed at an extrusion temperature of 240 ° C.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Example 2 having a different structure, both the loop stiffness and the impact strength showed lower values.

Example 3 Polypropylene D (MI =
2.5, linear low density polyethylene B (MI = 4,
Density = 0.905, flexural modulus = 140 MPa) resin and linear low density polyethylene G (MI = 3, density = 0.9)
02, a 1: 2 layer of resin having a flexural modulus of 95 MPa was applied to the intermediate layers b1 and b2 (density average = (0.905 × 1 +
0.902 × 2) / (1 + 2) = 0.903, average flexural modulus = (140 × 1 + 95 × 2) / (1 + 2) = 11
As 0 MPa), a film having a thickness of 100 μm sandwiched between the face material layers a and c having a thickness of 10 μm and the intermediate layers b1 and b2 having a thickness of 80 μm was extruded and formed at an extrusion temperature of 240 ° C.

The loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared to the film of Comparative Example 3 having a different structure, both the loop stiffness and the impact strength were higher.

Comparative Example 3 Using the same resin as in Example 3,
The order of the lamination structure was changed, and a film having a total thickness of 100 μm having a three-layer structure of polypropylene D 20 μm / linear low-density polyethylene B 27 μm / linear low-density polyethylene G 53 μm was extruded and formed at an extrusion temperature of 240 ° C.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Example 3 having a different structure, both the loop stiffness and the impact strength were lower.

[Example 4] Polyethylene terephthalate E (tensile modulus of elasticity = 3920 MPa) as face material layers a and c
No. 12 μm film, and as the intermediate layer b, an ionomer (a resin obtained by partially neutralizing the carboxyl group of a copolymer of ethylene and methacrylic acid with a metal) F (MI = 5.
5, a resin having a tensile modulus of elasticity of 98 MPa) having a thickness of 76 μm,
Extrusion was performed at an extrusion temperature of 290 ° C., and a polyurethane-based adhesive was used as an adhesive between the face material layer a and the c-intermediate layer b to form a 100 μm film having a sandwich structure.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Comparative Example 4 having a different structure, both the loop stiffness and the impact strength were higher.

[Comparative Example 4] The same film, resin and adhesive as in Example 4 were used, and the order of lamination was changed to obtain polyethylene terephthalate E 24 μm / ionomer 76 μm
Was extruded at 290 ° C. to form a film having a total thickness of 100 μm.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Example 4 having a different structure, both the loop stiffness and the impact strength showed lower values.

Example 5 Linear low-density polyethylene G synthesized with a metallocene catalyst (density = 0.902, M
I = 3, tensile modulus 50 MPa) 80 μm, linear low density polyethylene H synthesized with a metallocene catalyst (density = 0.885, MI = 2.5, tensile modulus = 250 M)
Pa) 20 μm is co-extruded and bonded to a biaxially stretched Ny film I and 15 μm via an adhesive, biaxially stretched nylon film I (15 μm) / linear low density polyethylene G (80 μm) / linear low density polyethylene H (20μ
m) was obtained.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Comparative Example 5 having a different structure, both the loop stiffness and the impact strength were higher.

In order to impart heat sealing properties to the surface of the linear low-density polyethylene G of this film, linear low-density polyethylene G was laminated by extrusion at 15 μm.
Since the sandwich structure of the biaxially stretched nylon film I (15 μm) / linear low-density polyethylene G (80 μm) / linear low-density polyethylene H (20 μm) was not broken, neither the loop stiffness nor the impact strength was impaired.

Comparative Example 5 The same film, resin and adhesive as in Example 5 were used, and the order of lamination was changed and the biaxially stretched nylon film I (15 μm) / linear low density polyethylene H (20 μm) / Linear low density polyethylene G (80
μm) was formed.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Example 5 having a different structure, both the loop stiffness and the impact strength were lower.

Example 6 In order to impart piercing strength to the film of Example 1, a biaxially stretched nylon film I was used.
(15 μm) via an adhesive, biaxially stretched nylon film I (15 μm) / linear low-density polyethylene A (20 μm) / linear low-density polyethylene B (60 μm)
m) / linear low-density polyethylene A (20 μm) four-layer film.

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Comparative Example 6 having a different structure, both the loop stiffness and the impact strength showed higher values.

Comparative Example 6 In order to impart piercing strength to the film of Comparative Example 1, a biaxially stretched nylon film I was used.
(15 μm) via an adhesive, biaxially stretched nylon film I (15 μm) / linear low-density polyethylene A (40 μm) / linear low-density polyethylene B (60 μm)
m) was obtained.

Using the same film, resin and adhesive as in Example 5, the order of lamination was changed and biaxially stretched nylon film I (15 μm) / linear low density polyethylene H (20 μm)
m) / linear low-density polyethylene G (80 μm).

Loop stiffness of this laminated film,
The impact strength was measured.

The results are shown in Table 1 below.

As compared with the film of Example 6 having a different constitution, both the loop stiffness and the impact strength showed lower values.

[0135]

[Table 1]

Next, the point of “excellent in waist strength and impact resistance” of the present invention will be described more clearly.

That is, the present invention relates to, for example, the first embodiment.
As can be seen from a comparison between Comparative Example 1 and Comparative Example 1, in the configuration of the laminated material having the same resin thickness when viewed as a whole, “hard 2
By setting the order of “0 / soft 60 / hard 20”, the waist strength and the waist strength are more improved than the configuration of “soft 60 / hard 40” or “soft 30 / hard 40 / soft 30” (that is, a configuration that does not take a sandwich structure). It is excellent in impact resistance, and as a result, there is an advantage that the overall thickness can be relatively reduced (the amount of resin used can be reduced).

(Other Embodiments) In each of the above embodiments, in a resin laminated film composed of a laminate composed of at least four resin layers, the laminate has four adjacent layers. Although the case where the two intermediate layers b1 and b2 are bonded and laminated between the two face material layers a and c has been described, the present invention is not limited to this. In the case of bonding and laminating three intermediate layers in between, for example, four or more adjacent layers are separated by two between the two face material layers.
The present invention can be similarly applied to a case where two or more intermediate layers are bonded and laminated with the intermediate layer interposed therebetween, and the same operation and effect as those described above can be obtained.

[0139]

As described above, according to the present invention, since the sandwich structure is formed by at least three or more resin layers or at least four resin layers, the waist strength is high and the impact resistance is high. A resin laminated film having excellent waist strength and excellent impact resistance can be provided.

Thus, it is possible to provide a resin laminated film having excellent strength and impact resistance, which have contradictory properties of impact strength and rigidity.

Furthermore, as the intermediate layer sandwiched between the two face material layers in the laminate, two or more intermediate layers are laminated, so that each layer of the laminate is bonded with an adhesive,
Alternatively, in the case of bonding through an adhesive resin, a resin laminated film excellent in waist strength and impact resistance capable of performing good bonding can be provided.

Therefore, by using the resin laminated film having excellent waist strength and impact resistance of the structure of the present invention, since it has both waist and impact strength, a film for a standing pouch, a film for a bag in a back-in-box, This makes it possible to develop various packaging films such as heavy packaging films and to reduce the amount of resin used in the films.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a resin laminated film having excellent waist strength and impact resistance according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the resin laminated film having excellent waist strength and impact resistance according to the present invention.

[Explanation of symbols]

 a ... face material layer, b ... middle layer, b1 ... middle layer, b2 ... middle layer, c ... face material layer.

 ────────────────────────────────────────────────── ─── Continuing on the front page F term (reference) 4F100 AB01E AB04A AB04D AB10A AB10D AK01A AK01B AK01C AK01D AK01E AK04A AK04B AK04C AK04D AK04E AK07A JA7 BA13A13 JA03 BA13B JK07B JK07C JK07D JK10 JL12A JL12B JL12C JL12D JL12E YY00

Claims (14)

[Claims] 1. A resin laminated film comprising a laminate comprising at least three or more resin layers, wherein the laminate comprises three intermediate layers each having one intermediate layer and two intermediate layers sandwiching the intermediate layer. It has a sandwich structure composed of a face material layer, and the elastic modulus of the same or different resin used for the face material layer sandwiching the intermediate layer is larger than the elastic modulus of the resin used for the intermediate layer. Resin laminated film with excellent waist strength and impact resistance. 2. A resin laminated film composed of a laminate composed of at least four resin layers, wherein the laminated body has at least two intermediate layers each having at least two adjacent layers. It has a sandwich structure consisting of two face material layers sandwiching an intermediate layer, and the elastic modulus of the same or different resin used for the face material layers sandwiching the intermediate layer is determined by the resin used for the intermediate layer. Resin laminated film excellent in waist strength and impact resistance characterized by having a modulus higher than that of 3. A resin laminated film comprising a laminate comprising at least three or more resin layers, wherein the laminate comprises three intermediate layers each having one intermediate layer and two intermediate layers sandwiching the intermediate layer. It has a sandwich structure consisting of a face material layer and the elastic modulus (E1, E3) of the same or different resin used for the face material layer sandwiching the intermediate layer, The elastic modulus ratio (E) is more than the elastic modulus (E2).
1 / E2, E3 / E2), a resin laminated film having excellent waist strength and impact resistance characterized in that the ratio is 1.2 times or more. 4. A resin laminated film composed of a laminate composed of at least four resin layers, wherein the laminated body has at least two intermediate layers each having at least two adjacent layers. It has a sandwich structure consisting of two face material layers sandwiching the intermediate layer, and the elastic modulus (E1, E3) of the same or different resin used for the face material layers sandwiching the intermediate layer is determined by the respective intermediate The elasticity ratio (E1 / E2, E3 / E2) is at least 1.2 times larger than the average elastic modulus (E2) of the resin used for the layer, and the waist strength and impact resistance are characterized by Excellent resin laminated film. 5. A resin laminated film composed of a laminate composed of at least four resin layers, wherein the laminate has at least two intermediate layers each having at least two adjacent layers. It has a sandwich structure consisting of two face material layers sandwiching the intermediate layer, and the elastic modulus of the same or different resin used for the face material layers sandwiching the intermediate layer is used for the respective intermediate layers. A resin laminated film excellent in waist strength and impact resistance, characterized in that the elastic modulus is larger than the largest elastic modulus of the resin. 6. The resin laminated film having excellent waist strength and impact resistance according to claim 1 or 3, wherein the thickness of the resin used for the intermediate layer is determined by adjusting the thickness of the resin of the face material layer. Resin laminated film with excellent waist strength and impact resistance characterized by having a thickness greater than the thickness of the layer. 7. The resin laminated film having excellent waist strength and impact resistance according to any one of claims 2, 4, and 5, wherein the resin used for each of the intermediate layers. Characterized in that the total thickness of the resin laminated film is larger than the thickness of the resin layer of the face material layer. 8. The method according to claim 1, wherein
The resin laminated film having excellent waist strength and impact resistance according to the above item, wherein at least one of the layers used for the face material layer is a metal layer such as aluminum or stainless steel. Resin laminated film with excellent waist strength and impact resistance. 9. The method according to claim 1, wherein
The resin laminated film having excellent waist strength and impact resistance according to the paragraph, wherein a surface layer made of a resin layer or a metal layer is laminated on one or both surfaces of the outer surface of the laminate forming the sandwich structure. Resin laminated film with excellent waist strength and impact resistance. 10. The resin laminated film having excellent waist strength and impact resistance according to any one of claims 1 to 9, wherein the resin laminated film is used for each layer of the laminate forming the sandwich structure. A resin laminated film excellent in waist strength and impact resistance, characterized in that the resins are made of the same kind of resin which is heat-sealed. 11. The resin laminated film according to claim 10, wherein the resin of the same kind is a polyethylene-based resin, and a density of the resin used for the face material layer. Wherein the density is higher than the density of the resin used in the intermediate layer. 12. The resin laminated film according to claim 10, wherein the resin of the same kind is a polyethylene resin, and the density of the resin used for the face material layer. (D1, D3) is a density difference (D1−D2, A resin laminated film excellent in waist strength and impact resistance, characterized in that D3-D2) is increased by 0.015 or more. 13. The resin laminated film according to claim 10, wherein the resin of the same kind is a polyolefin resin, and the resin used for the face material layer is polypropylene. A resin laminated film having excellent waist strength and impact resistance, wherein a linear resin and a resin used in the intermediate layer are linear polyethylene resins. 14. The resin laminate film having excellent waist strength and impact resistance according to any one of claims 1 to 9, wherein the resin laminate film is used for each layer of the laminate forming the sandwich structure. A resin laminated film excellent in waist strength and impact resistance, wherein different resins are used as the resins, and the respective layers are bonded to each other via an adhesive or an adhesive resin.