JP2018099834A - Laminate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag-making material having such properties that even when a packaging bag is torn in a direction different from an initially planned direction upon opening the bag, the bag can be open at an angle close to the planned direction.SOLUTION: A laminate film 5 having an outer layer 1, an intermediate layer 2 and a sealant layer 3, in this order, is provided, in which the outer layer 1 and the intermediate layer 2 are formed of direct-advance films, while the sealant layer 3 satisfies both of the following conditions (1) and (2). (1) The sealant film has a Young's modulus of 200 MPa or more in an MD direction of the laminate film; and (2) the sealant film has a tear strength of 1.0 N or more and 5.0 N or less in the MD direction of the laminate film.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated film.

  Conventionally, laminated films made of various materials have been proposed as sachets for filling and packaging liquids such as foods, seasonings, pharmaceuticals, and supplements, viscous materials, and powders. These laminated films are provided as, for example, a pouch-shaped filling and packaging bag, and the user tears and opens the pouch using, for example, a notch as a clue, and uses (for example, eats) the contents.

  For this reason, in the field of laminated films, various techniques relating to comfortable openability have been proposed in addition to barrier performance for protecting contents from the external environment, sealing performance that provides sufficient sealing performance, and the like.

  For example, in Patent Document 1, a sealing layer made of a polyethylene film is laminated on a base material layer, and the tear strength from a notch formed in an edge is 0.4 N or less and the impact strength is 0.7 J or more. A packaging laminate is described, which is described as providing a packaging bag having the required strength and good tearability.

  In Patent Document 2, a stretched polypropylene film having a unidirectional tearability and a barrier film are laminated, and at least two laminated films formed with a sealant layer on either side thereof are matched with each other in the tearing direction. A packaging bag is described in which a sealant layer is laminated so as to face each other, and a peripheral portion thereof is sealed to form a bag. The package has excellent oxygen gas barrier properties, pinhole resistance, and the like, and is unidirectionally torn. It is described as having a sex. The packaging bag described in Patent Document 2 is intended for use as an outer bag for an infusion bag that is filled with a relatively large volume of injection solution or the like.

JP 2006-51995 A JP 2006-256626 A

  In the techniques of Patent Documents 1 and 2, when a user applies stress in a predetermined direction at the time of opening and tries to tear in the originally planned direction, the user can tear comfortably in that direction.

  However, for example, in the case of a user whose freedom of hand is restricted due to disease, injury, aging, etc., in special (but likely) situations such as nursing care sites, the user is required to open the packaging bag at the time of opening. The stress applied to is not necessarily the same as the originally planned opening direction. The packaging bag in this case may be torn, for example, obliquely according to the direction of the applied stress, or may be torn in a direction different from both the originally planned direction and the direction of the applied stress. .

  When the packaging bag is torn and opened in a direction different from the originally planned direction, the opening is usually larger than planned. The take-out diameter of the contents taken out from the opening that is larger than the plan becomes larger than the plan. Here, when the content is a high-viscosity food such as a jelly food or an oat, it may not be preferable that the diameter is excessively large.

  The present invention has been made under the circumstances as described above. Accordingly, an object of the present invention is to provide a bag-making material that can be opened at an angle close to the planned direction even when the packaging bag is torn in a direction different from the originally planned direction. That is.

  The present invention is as follows.

[1] A laminated film having an outer layer, an intermediate layer, and a sealant layer in this order,
The outer layer and the intermediate layer are made of a straight cut film,
The sealant layer has the following conditions (1) and (2):
(1) The Young's modulus in the MD direction of the laminated film is 200 MPa or more, and (2) the tear strength in the MD direction of the laminated film is 1.0 N or more and 5.0 N or less.
The laminated film satisfying both of the above.

  [2] The outer layer and the intermediate layer are each independently composed of a straight cut film selected from a uniaxially stretched polypropylene film, a biaxially stretched polyethylene terephthalate film, and a biaxially stretched nylon film. Laminated film.

  [3] The laminated film according to [1] or [2], wherein the sealant layer is a linear low density polyethylene film.

  [4] The laminated film according to any one of [1] to [3], further including a barrier layer between the outer layer and the intermediate layer, or between the intermediate layer and the sealant layer.

  [5] A packaging bag comprising the laminated film according to any one of [1] to [4].

  Even when the laminated film of the present invention is torn and opened in a direction different from the originally planned direction, it can be opened at an angle close to the planned direction. The laminated film of the present invention is extremely suitable because it produces a filled packaging bag (for example, a pouch) containing high-viscosity foods such as jelly foods and sheepskin.

FIG. 1 is a schematic cross-sectional view for explaining a laminated structure of an embodiment of the laminated film of the present invention. FIG. 2 is a schematic cross-sectional view for explaining a laminated structure of another embodiment of the laminated film of the present invention. 3A to 3C are diagrams for explaining a method for measuring the straight cut property of a laminated film.

  Hereinafter, the present invention will be described focusing on preferred embodiments thereof.

<Laminated film>
The laminated film of the present invention is
A laminated film having an outer layer, an intermediate layer, and a sealant layer in this order,
The outer layer and the intermediate layer are made of a straight cut film,
The sealant layer has the following conditions (1) and (2):
(1) The Young's modulus in the MD direction of the laminated film is 200 MPa or more, and (2) the tear strength in the MD direction of the laminated film is 1.0 N or more and 5.0 N or less.
Satisfy both.

  FIG. 1 shows a laminated structure of a laminated film in an embodiment of the present invention. A laminated film 5 in FIG. 1 has an outer layer 1, an intermediate layer 2, and a sealant layer 3 in this order from the top of the figure.

  In another embodiment, the laminated film of the present invention may further include a barrier layer between the outer layer and the intermediate layer, or between the intermediate layer and the sealant layer.

  FIG. 2 shows a laminated structure of a laminated film having a barrier layer. The laminated film 5 in FIG. 2A has an outer layer 1, a barrier layer 4, an intermediate layer 2, and a sealant layer 3 in this order from the top of the figure. On the other hand, the laminated film of FIG. 2B has an outer layer 1, an intermediate layer 2, a barrier layer 4, and a sealant layer 3 in this order from the top of the figure. The laminated film of this embodiment may have any of the laminated structures shown in FIGS. 2 (a) and 2 (b).

[Outer layer]
The outer layer in the laminated film of the present embodiment has impact resistance sufficient to protect the package and contents from physical impact applied after the production of the packaging bag, preferably also has barrier properties and is unidirectional tearable It is appropriate that the film is made of a straight-cut film having excellent resistance.

  The “straight cut film” is a film having a property of being easily torn in a specific direction, and is typically a uniaxially stretched film or a biaxially stretched film. The direction in which tearing is easy is the stretching direction in the case of a uniaxially stretched film, and may be a specific direction in the stretching direction in the case of a biaxially stretched film.

  The material of the film constituting the outer layer in this embodiment may be, for example, polypropylene, polyethylene terephthalate, nylon or the like. Preferably, it is a straight cut film selected from uniaxially stretched polypropylene, biaxially stretched polyethylene terephthalate, and biaxially stretched nylon.

  The thickness of the outer layer is not particularly limited. The thickness of the outer layer may be, for example, 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more in order to give sufficient strength and good straight cut property to the resulting packaging bag. On the other hand, the upper limit value of the thickness of the outer layer is to reduce the excessive vibration of ultrasonic vibrations when applying the ultrasonic wave to the seal at the time of bag making, in terms of improving the visibility of the contents when the packed package is displayed. From the viewpoint of avoidance, it may be 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, or 30 μm or less.

  A commercially available product may be used as the outer layer in the present embodiment. Examples of commercially available straight-cut polypropylene film include “MCMD-NBT” manufactured by Futamura Chemical Co., Ltd., “ASS” and “ANN” manufactured by Tokyo Ink. As a commercial product of the straight cut polyethylene terephthalate film, for example, a product name “PCBC” manufactured by Unitika Ltd. can be exemplified. Examples of commercially available products of the straight-cutting nylon film include a product name “NCBC” manufactured by Unitika, a product name “TB-1010” manufactured by Idemitsu Unitech, and the like.

[Middle layer]
It is appropriate that the intermediate layer in the laminated film of the present embodiment is made of a straight-cut film having a function of giving the whole laminated film a waist and increasing the bag breaking strength and having excellent unidirectional tearability. The “straight cut film” in this case may be understood in the same manner as in the outer layer.

  The material of the film constituting the intermediate layer in this embodiment may be, for example, polypropylene, polyethylene terephthalate, nylon or the like. Preferably, it is a straight cut film selected from uniaxially stretched polypropylene, biaxially stretched polyethylene terephthalate, and biaxially stretched nylon, more preferably a straight cut film selected from biaxially stretched polyethylene terephthalate and biaxially stretched nylon. It is.

  The thickness of the intermediate layer in the laminated film of the present embodiment may be, for example, 5 μm or more, 7 μm or more, or 10 μm or more, for example, 40 μm or less, 30 μm or less, or 20 μm or less.

  A commercially available product may be used as the intermediate layer in the present embodiment. As a commercial product of the straight cut polyethylene terephthalate film, for example, a product name “PCBC” manufactured by Unitika Ltd. can be exemplified. As a commercial item of a straight cut nylon terephthalate film, for example, a product name “NCBC” manufactured by Unitika Ltd., a product name “TB-1010” manufactured by Idemitsu Unitech Co., Ltd. can be exemplified.

[Sealant layer]
The sealant layer in the laminated film of the present embodiment can support the straight cut property of the outer layer and the intermediate layer, and preferably has heat resistance to withstand the heat sterilization treatment of the contents, and provides a seal during bag making. In the case of applying ultrasonic waves, it is appropriate to use materials that can be melted by friction caused by ultrasonic vibration and fused together.

The sealant layer in the laminated film of the present embodiment has the following conditions (1) and (2):
(1) The Young's modulus in the MD direction of the laminated film is 200 MPa or more, and (2) the tear strength in the MD direction of the laminated film is 1.0 N or more and 5.0 N or less.
It is necessary to satisfy both of these.

  The (1) Young's modulus of the sealant layer can be measured by an ordinary method in accordance with JIS K7127. The Young's modulus of the sealant layer favorably supports the straight cut ability of the outer layer and the intermediate layer, and suppresses the attenuation of vibration caused by ultrasonic waves when the bag-making seal is applied by ultrasonic waves, thereby providing a good contaminant sealability. In order to ensure, it needs to be 200 MPa or more in the laminated film MD direction, and may be, for example, 210 MPa or more, 220 MPa or more, or 225 MPa or more. On the other hand, when the seal at the time of bag making is applied by applying ultrasonic waves, the Young's modulus in the direction of the laminated film MD of the sealant layer from the viewpoint of ensuring the formation of a strong seal by melting due to friction caused by ultrasonic waves, It may be 750 MPa or less, 600 MPa or less, 500 MPa or less, 400 MPa or less, or 300 MPa or less.

  When the Young's modulus of the sealant layer varies depending on the direction, it is preferable to laminate by selecting a direction satisfying the above requirements when a laminated film is formed.

  The sealant layer in this embodiment is required to have (2) tear strength in the MD direction of the laminated film of 1.0 N or more and 5.0 N or less. By satisfying this requirement, the resulting laminated film exhibits extremely high straight cut properties.

  When a sealant layer showing a high tear strength of 1.0 N or more is used, it is difficult to cut the sealant layer alone, so that the direction in which the entire laminated film is cut is cut in the direction defined by the straight cut film. Will be dependent. Therefore, it is presumed that the inductivity in the tear direction expected by the present embodiment can be maintained, and therefore, the straight cut property of the entire laminated film is excellent.

  On the other hand, if the tear strength of the sealant layer is excessively high, the comfortable hand cutting property of the entire laminated film is impaired.

  Therefore, when the tear strength of the sealant layer is 1.0 N or more and 5.0 N or less in the laminated film MD direction, the effect of the present invention is manifested.

  The tear strength in the MD direction of the sealant layer may be 1.2N or more, 1.5N or more, 2.0N or more, or 2.5N or more, 4.0N or less, 3.5N or less, or 3.0N. It may be the following.

  The tear strength in this specification is not a value in units of N / mm in which the tear force (N) is assigned by the thickness (mm) of the test piece, but the tear force (unit: N) required to tear the film itself. Yes, it can be measured according to JIS K7128.

  The thickness of the sealant layer is preferably more than 15 μm, and may be 20 μm or more, 30 μm or more, or 40 μm or more from the viewpoint of forming a strong seal during bag making. On the other hand, when the seal at the time of bag making is applied by applying ultrasonic waves, it is possible to suppress the attenuation of vibration due to ultrasonic waves as much as possible, and from the viewpoint of avoiding obstruction of the straight cut property of the outer layer and the intermediate layer, The thickness is preferably 100 μm or less, and may be 80 μm or less, 75 μm or less, 70 μm or less, 65 μm or less, or 60 μm or less.

  In addition to satisfying the above requirements, the sealant layer in the present embodiment preferably has a heat of fusion of 110 J / g or less from the viewpoint of further improving the ultrasonic sealing properties, particularly the contaminant sealing properties by ultrasonic waves. From this viewpoint, the heat of fusion of the sealant layer may be 107.5 J / g or less, or 105 J / g or less. On the other hand, from the viewpoint of forming a strong seal, the heat of fusion of the sealant layer may be 50 J / g or more or 75 J / g or more.

  Specific examples of the material for the sealant layer in the present embodiment include, for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and polypropylene (PP). , Ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-propylene copolymer (EPM), polymethylpentene, Examples include materials such as polybutene. Among these, LLDPE is preferable because it exhibits good ultrasonic sealing properties, particularly good foreign matter sealing performance by application of ultrasonic waves, and can support the straight cut property of the outer layer well.

  The sealant layer in the present embodiment may be a single layer body or a multilayer body as long as the above requirements are satisfied as a whole.

  A commercially available product may be used as the sealant layer in the present embodiment. Examples of commercially available linear low density polyethylene films satisfying the predetermined requirements of the present embodiment include, for example, product names “SE620L” and “SE625L” manufactured by Tamapoli, product names “L105” manufactured by Aicello, and product names “Idemitsu Unitech” LS-700C ”, a product name“ HR611 ”manufactured by Skyfilm Corporation, and the like.

[Barrier layer]
The barrier layer preferably used in the laminated film of this embodiment is a layer having a function of protecting the contents by suppressing the intrusion of gas (particularly oxygen), moisture, and light from the outside.

  As a material which comprises the barrier layer in the laminated | multilayer film of this embodiment, aluminum, a silica, a polyvinylidene chloride, polyvinyl alcohol etc. can be mentioned, for example.

  The barrier layer may be used for the production of the laminated film of the present embodiment as an independent film or foil, or a laminate that is supplied in a layered state in advance on one or both sides of a suitable base film. May be used as they are. When the barrier layer is a layer formed on the base film, the base film may also serve as the aforementioned outer layer or intermediate layer. Preferably, the base film also serves as an intermediate layer. As said base film, the film which consists of polyethylene terephthalate, nylon etc. can be mentioned, for example.

  In the laminated film of the present embodiment, when the barrier layer is a laminated body supplied in a state of being formed on the base film, the base film preferably serves as an intermediate layer. Examples of the laminate that can be suitably used in such a case include polyvinylidene chloride coated / biaxially stretched nylon, polyvinylidene chloride coated / biaxially stretched polyethylene terephthalate, aluminum vapor deposited / biaxially stretched polyethylene terephthalate, aluminum vapor deposited / biaxial Axial stretched nylon, silica vapor deposited / biaxially stretched polyethylene terephthalate, silica vapor deposited / biaxially stretched nylon, polyvinyl alcohol / biaxially stretched polypropylene, polycarboxylic acid polymer / biaxially stretched nylon, metaxylenediamine-biaxially stretched nylon composite film , Ethylene vinyl alcohol copolymer-biaxially stretched nylon composite film, and the like.

The thickness of the barrier layer is
When the barrier layer is provided as an independent film or foil, it can be, for example, 1 μm or more, 3 μm or more, or 5 μm or more, for example, 10 μm or less, or 8 μm or less,
When the barrier layer is provided as a layer formed on the base film, it can be, for example, 1 nm or more, 3 nm or more, or 5 nm or more, for example, 500 nm or less, 300 nm or less, or 200 nm or less.

  A typical example where the barrier layer is used as an independent film or foil is aluminum foil.

  When the barrier layer is a laminated body supplied in a layered state on the base film, examples of the commercial product of the laminated body include a product name “BK” manufactured by Oike Pack Material Co., Ltd., Kojin Film & Chemicals' product name “KBC”, Daicel Value Coating's “KET600”, Toray Film Processing's product names “BR1012”, “BR1412”, “BR-ON7012”, Unitika's product names “HGB”, “ DCTU "and the like.

[Optional components in each layer]
Each of the above layers may contain an appropriate additive as necessary. Examples of the additive used here include a lubricant, an antioxidant, an antistatic agent, a colorant and the like.

  The laminated film of the present embodiment is assumed to be printed with a product name, a product logo, etc. for identification of contents when used as a packaging bag or for appealing to consumers when displayed as a product. The Printing can be performed on any surface of any layer of the laminated film. However, it is preferable to avoid printing on the outside of the outer layer and on the inside of the sealant layer for printing protection.

[Fix between each layer]
It is preferable that each layer in the laminated film of the present embodiment is fixed by an appropriate adhesive. The adhesive in this case can be appropriately selected by those skilled in the art depending on the method for producing the laminated film. For example, an adhesive for dry lamination, an adhesive for print lamination, an AC agent for extrusion lamination, and the like. The amount of the adhesive can be, for example, 0.5 g / m ² or more, preferably 1 g / m ² or more for each layer as an adhesive material per unit film area. On the other hand, the amount of the adhesive can be, for example, 10 g / m ² or less, and preferably 5 g / m ² or less.

[Lamination direction of laminated film]
The outer layer and the intermediate layer in the laminated film of this embodiment are each composed of a straight cut film. In the sealant layer and the laminated film, there are an MD direction and a TD direction, respectively. In the present embodiment, it is preferable to appropriately set these directions in the laminated film from the viewpoint of effectively expressing a high degree of straight cut.

In the laminated film of the present embodiment, most preferably
It is to make the easy tear direction of the outer layer and the intermediate layer coincide with the MD direction of the sealant layer. It is preferable to adjust the direction of each layer in this way from the viewpoint of maximizing the effects of the present invention.

[Thickness of laminated film]
The thickness (total film thickness) of the laminated film of this embodiment is preferably 150 μm or less from the viewpoint of realizing good sealing properties. The thickness of the laminated film may be, for example, 120 μm or less, 100 μm or less, or 90 μm or less. On the other hand, from the viewpoint of giving practical geometric strength to the laminated film, the thickness of the laminated film may be, for example, 35 μm or more, 50 μm or more, or 60 μm or more.

[Straight cut of laminated film]
The laminated film of this embodiment has excellent straight cut properties. For example, the straight cut property is obtained by changing the tear direction when a tear test is performed using a sample punched so that the long side is at an angle of 45 ° with respect to the MD direction of the laminated film with respect to the MD direction. Thus, the angle can be set to 12 ° or less.

  In FIG. 3, the outline of the measuring method of the straight cut property of a laminated | multilayer film was shown. First, the sample is punched so that the long side is at an angle of 45 ° with respect to the MD direction of the laminated film (FIG. 3A). Using this sample, a normal tear test is performed (FIG. 3B). Then, the angle between the direction of the tear break caused by the tear test and the MD direction of the laminated film is used as an index of the straight cut property (FIG. 3C).

  The smaller the angle measured as described above, the closer to the original direction the opening is made when a stress is applied in a direction different from the originally intended opening direction. In this case, since the diameter of the content outlet is not excessively large, it is possible to avoid accidental suffocation of the eater when the content is a high-viscosity food. The angle can be 10 ° or less, 9 ° or less, 8 ° or less, or 7 ° or less, and can be 6 ° or less, 5 ° or less, 4 ° C or less, or 3 ° or less. .

  The above tear test can be performed according to JIS K7128-1, except that the punching angle of the sample is as described above.

<Method for producing laminated film>
The laminated film of the present embodiment can be produced by a known method except that the above layers are laminated in a predetermined order. For example, it can be manufactured by a dry lamination method, a wet lamination method, an extrusion lamination method, or a combination thereof. Of these, the dry laminating method is preferable. Dry laminating can be performed by a known method using a known dry laminating adhesive, for example, a polyester-based adhesive, a polyether-based adhesive, a polyurethane-based adhesive, or the like.

<Bag making method>
The laminated film of this embodiment is excellent in ultrasonic sealing properties, and in particular, is excellent in contaminant sealing properties due to application of ultrasonic waves. Therefore, the laminated film of the present embodiment is preferably used for bag making and filling with an ultrasonic sealing step, and is preferably used for bag making and filling with a foreign matter sealing step.

  At the time of bag making, first, the laminated film of the present embodiment is opposed so that the sealant layers face each other, or folded, and two sides facing each other or one side facing the folded portion are heat-sealed, A cylindrical molded body with two facing sides closed. In this molded body, the two closed sides constitute the bottom and top sides of the package.

  At this time, it is preferable that the tearing easy direction of the outer layer and the intermediate layer of the laminated film coincide with the opening direction of the cylindrical body. By adopting such a configuration, it becomes easy to open in the direction orthogonal to the height direction in the obtained package, and the opening diameter does not greatly exceed the planned diameter, so the content is a high-viscosity food. In this case, suitable application is possible.

  Next, the cylindrical molded body as described above is mounted on a commercially available bag making machine equipped with an ultrasonic sealing device to make a bag. Here, it is preferable to use a bag making and filling machine that performs bag making while filling the contents as the bag making machine, and perform bag making and filling in an embodiment in which the ultrasonic seal is a contaminant seal.

  In the following Examples and Comparative Examples, the details of the resin films used as materials constituting each layer are as shown in Table 1 below. In Table 1, the word “Tear” at the beginning of the abbreviation is a straight cut film. The numerical value following “#” in the abbreviation indicates the film thickness in μm.

<Examples 1-4 and Comparative Examples 1-4>
(1) Production of laminated film A laminated film was produced as follows using the films shown in Table 2 as the outer layer, the intermediate layer, and the sealant layer. No barrier layer was used in the production of this laminated film.

  A laminated film was produced by laminating an outer layer and a sealant layer on both sides of the intermediate layer by dry lamination under the intervention of a dry laminate adhesive (manufactured by Rock Paint, “RU-50”). At this time, except for Comparative Example 1, the laminating direction was adjusted so that the directions indicating the straight cut property in the films constituting the outer layer and the intermediate layer coincided with each other, and this direction was taken as the MD direction of the laminated film. In Comparative Example 1, the direction in which the intermediate layer exhibited straight cut performance was defined as the MD direction of the laminated film.

(2) Evaluation of rectilinear cutting property A test piece having a length of 150 mm and a width of 20 mm was cut out from the laminated film obtained above so that the long side formed an oblique 45 ° angle with respect to the film MD direction. An incision of about 75 mm was made on the center line in the long side direction of the test piece, and it was torn at a speed of 1,000 mm / min in the incision direction using a tensile tester. Then, the angle between the straight line connecting the starting point to the completion point of the tearing part generated by the test and the film MD direction was examined (see FIG. 3). The results are shown in Table 2.

<Examples 5 and 6 and Comparative Examples 5 and 6>
(1) Production of laminated film Laminated films were produced as follows using the films shown in Table 3 as the outer layer, barrier layer, intermediate layer, and sealant layer.

  An outer layer, a barrier layer, an intermediate layer, and a sealant layer were laminated in this order, and a laminated film was produced by dry laminating each layer with a dry laminate adhesive “RU-50” interposed therebetween. At this time, in Examples 5 and 6, the laminating direction was adjusted so that the directions indicating the straight cut property in the films constituting the outer layer and the intermediate layer coincided with each other, and this direction was taken as the MD direction of the laminated film. In Comparative Example 6, the direction in which the outer layer exhibited straight cut performance was defined as the MD direction of the laminated film.

(2) Evaluation of rectilinear cut property The rectilinear cut property was evaluated in the same manner as in Example 1 using each laminated film obtained above. The evaluation results are shown in Table 3.

<Examples 7-9 and Comparative Examples 7-14>
(1) Production of Laminated Film A laminated film was produced as follows using the films shown in Table 4 as the outer layer, barrier layer / intermediate layer, and sealant layer. “Barrier / intermediate layer” means that a barrier layer is previously layered on a base film by depositing an aluminum layer or coating a resin layer having a barrier function on one surface of a resin film as a base film. The laminate formed in the above.

  Laminate by dry laminating the outer layer on the barrier layer side of the barrier layer / intermediate layer and the sealant layer on the intermediate layer side with a dry laminate adhesive ("RU-50", manufactured by Rock Paint Co., Ltd.). A film was produced. At this time, except for Comparative Examples 7 and 11 to 14, the laminating direction is adjusted so that the direction indicating the straight cut property in the film constituting each of the outer layer and the intermediate layer matches, and this direction is the MD direction of the laminated film. did. In Comparative Examples 7 and 12-14, the direction in which the outer layer exhibits straight-cutting properties was defined as the MD direction of the laminated film, and in Comparative Example 11, the direction in which the intermediate layer exhibited straight-cutting properties was defined as the MD direction of the laminated film.

(2) Evaluation of rectilinear cut property The rectilinear cut property was evaluated in the same manner as in Example 1 using each laminated film obtained above. The evaluation results are shown in Table 4.

  In Tables 2 to 4, the description in bold in the comparative example indicates that the comparative example deviates from the predetermined requirement of the present invention in the portion described in bold.

  The Young's modulus of each sealant layer used in each of the above examples and comparative examples was measured according to JIS K7127. The tear strength of each sealant layer was measured according to JIS K7128-1.

1 outer layer 2 intermediate layer 3 sealant layer 4 barrier layer 5 laminated film

Claims (5)

A laminated film having an outer layer, an intermediate layer, and a sealant layer in this order,
The outer layer and the intermediate layer are made of a straight cut film,
The sealant layer has the following conditions (1) and (2):
(1) The Young's modulus in the MD direction of the laminated film is 200 MPa or more, and (2) the tear strength in the MD direction of the laminated film is 1.0 N or more and 5.0 N or less.
The laminated film satisfying both of the above.   The laminated film according to claim 1, wherein the outer layer and the intermediate layer are each independently composed of a straight-cut film selected from a uniaxially stretched polypropylene film, a biaxially stretched polyethylene terephthalate film, and a biaxially stretched nylon film.   The laminated film according to claim 1 or 2, wherein the sealant layer is a linear low density polyethylene film.   The laminated film according to any one of claims 1 to 3, further comprising a barrier layer between the outer layer and the intermediate layer, or between the intermediate layer and the sealant layer.   The packaging bag which consists of a laminated | multilayer film as described in any one of Claims 1-4.

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