JP2017217902A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag-making material capable of producing a filling and packaging bag which can be opened at an angle close to a scheduled direction even when torn in a direction different from the originally scheduled direction when the packaging bag is opened, and is excellent in impurities sealability when ultrasonic seal is adopted.SOLUTION: A laminated film 5 has an outer layer 1 composed of a uniaxial stretched polypropylene film, a barrier layer 2 and a resin intermediate layer 3 in a random order, and a sealant layer 4 in this order, where the sealant layer 4 satisfies all following conditions: (1) a Young's modulus in a laminated film MD direction is 200 Mpa or more; (2) a film thickness is 2.5 times or less the film thickness of the outer layer 1; and (3) a tensile strength in the laminated film MD direction is 1N or more and 5N or less.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 one-way tear property and a barrier film are laminated, and the sealant layer is opposed so that the tear direction coincides with a laminated film in which a sealant layer is provided on at least one side thereof In addition, a packaging bag is described in which a peripheral portion is sealed and formed into a bag shape, and it is described that the package has excellent oxygen gas barrier properties, pinhole resistance, and the like, and has unidirectional tearability. 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 wider than planned increases. Here, in the case where the contents are high viscosity foods such as jelly foods and sheepskin, if the diameter is large, it may not be preferable when aspiration is performed.

  By the way, when manufacturing a filling packaging bag, the contents often adhere to the seal portion. In particular, when performing so-called “bag-filling” in which a packaging bag is manufactured while filling the contents, it is inevitable that the contents adhere to the seal portion. Therefore, the bag making material used for bag filling is required to have “contaminant sealability” or “contamination sealability” that exhibits high sealing performance even if the contents (contaminants) adhere to the seal portion. .

  Generally, the packaging bag is sealed by heat sealing. However, heat sealing generally requires a process time of several seconds per bag (1 to 3 seconds in a typical foreign matter seal), and cannot be said to be sufficiently fast. In this regard, in the case of ultrasonic sealing that seals by applying ultrasonic waves, the process time per bag is less than 1 second (for example, 0.1 to 0.5 seconds). Therefore, from the request to shorten the bag making process time, a bag making material having a good sealing property when an ultrasonic seal is employed is required.

  The present invention has been made under the circumstances as described above. Therefore, an object of the present invention is to open the packaging bag at an angle close to the planned direction even when it is torn in a direction different from the originally planned direction. It is providing the bag making material which can manufacture the filling packaging bag excellent in the sealing property of foreign materials, when adopting.

  The present invention is summarized as follows.

[1] An outer layer made of a uniaxially stretched polypropylene film;
Barrier layer and resin intermediate layer in any order,
A sealant layer,
In this order,
The sealant layer has the following conditions (1) to (3):
(1) Young's modulus in the laminated film MD direction is 200 MPa or more,
(2) The film thickness is 2.5 times or less of the film thickness of the outer layer, and (3) The tear strength in the laminated film MD direction is 1N or more and 5N or less,
The laminated film satisfying all of the above.

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

  [3] The laminated film according to [1] or [2], wherein the tear strength in the MD direction of the sealant layer is 1N or more and 3N or less.

  [4] A packaging bag formed by sealing the sealant layers of the laminated film according to any one of [1] to [3].

  [5] The packaging bag according to [4], wherein the seal is a contaminant seal using ultrasonic waves.

  [6] A bag-making method comprising a step of ultrasonically sealing the sealant layers of the laminated film according to any one of [1] to [3].

[7] The ultrasonic sealing step is an ultrasonic contaminant sealing step.
The bag making method according to [6].

  The laminated film of the present invention can be opened at an angle close to the planned direction even when the film is torn and opened in a direction different from the originally planned direction, and an ultrasonic seal is employed. In addition, it is possible to manufacture a filled packaging bag having excellent sealing properties for impurities. 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 the laminated structure of the laminated film of the present invention. FIG. 2 is an explanatory view showing the procedure of the bag making and filling process in the embodiment. 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 in detail.

<Laminated film>
The laminated film of the present invention is
An outer layer made of uniaxially stretched polypropylene film;
Barrier layer and resin intermediate layer in any order,
A sealant layer,
In this order,
The sealant layer has the following conditions (1) to (3):
(1) Young's modulus in the laminated film MD direction is 200 MPa or more,
(2) The film thickness is 2.5 times or less of the film thickness of the outer layer, and (3) The tear strength in the laminated film MD direction is 1N or more and 5N or less,
It is characterized by satisfying all of the above. In the above description, the fact that the laminated film is in any order and has a barrier layer and a resin intermediate layer indicates that the order of laminating these two layers may be any order.

  In FIG. 1, the laminated structure of the laminated | multilayer film of this invention was shown. The laminated film in FIG. 1A has an outer layer 1, a barrier layer 2, a resin intermediate layer 3, and a sealant layer 4 in this order from the top of the figure. On the other hand, the laminated film of FIG. 1B has an outer layer 1, a resin intermediate layer 3, a barrier layer 2, and a sealant layer 4 in this order from the top of the figure. The laminated film of the present invention may have any of the laminated structures shown in FIGS. 1 (a) and (b).

[Outer layer]
The outer layer in the laminated film of the present invention has impact resistance sufficient to protect the package and contents from physical impact applied after the manufacture of the packaging bag, and preferably has barrier properties and is unidirectional tearable. It is appropriate to consist of excellent materials.

  In the present invention, uniaxially stretched polypropylene is used as the outer layer of the laminated film. As will be verified in the examples described later, when an outer layer made of another material known to have excellent unidirectional tearability in the prior art is used, stress is applied in a direction different from the originally planned direction. When is added, it cannot be opened at an angle close to the planned direction. In the present specification, hereinafter, the property that can be opened at an angle close to the planned direction even when stress is applied in a direction different from the originally planned direction is expressed using the term “straight cut”. To do.

  A commercially available product may be used as the uniaxially stretched polypropylene in the present invention. Examples of such commercially available products include MCMD-AS, MCMD-AS2, MCMD-NBT manufactured by Futamura Chemical Co., Ltd .; ANNM, ANN, ASCM, ASC, ASS manufactured by Tokyo Ink Co., Ltd., and the like.

  The thickness of the outer layer is not particularly limited. In order to give sufficient strength and good straight cut property to the resulting packaging bag, for example, it can be 7 μm or more, and preferably 10 μm or more. On the other hand, the upper limit value of the thickness of the outer layer is set to 50 μm or less from the viewpoint of avoiding vibration attenuation due to application of ultrasonic waves at the time of sealing and improving the visibility of the contents when the packed package is displayed. The thickness is preferably 30 μm or less.

[Barrier layer]
The barrier layer preferably used in the laminated film of the present invention is a layer having a function of protecting the contents by suppressing 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 invention, 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 invention as an independent film or foil, or a laminated material supplied in a layered state in advance on one or both sides of a suitable base film. You may use as it is. When the barrier layer is a layer formed on the base film, the base film may also serve as the above-mentioned outer layer or a resin intermediate layer described later. Preferably, the base film also serves as a resin intermediate layer. As said base film, the film which consists of polyethylene terephthalate, nylon etc. can be mentioned, for example.

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.

[Resin intermediate layer]
The resin intermediate layer in the laminated film of the present invention is a layer having a function of imparting waist to the whole laminated film and increasing the bag breaking strength.

  Examples of the resin intermediate layer in the laminated film of the present invention include polyethylene terephthalate, nylon, and polypropylene.

  The resin intermediate layer may be unstretched, or may be uniaxially stretched or biaxially stretched. Particularly preferred is a layer containing a biaxially stretched resin film. By including the resin film in which the resin intermediate layer is biaxially stretched, the waist of the entire laminated film is improved and the bag breaking strength is increased.

  A commercially available product may be used as the resin intermediate layer in the laminated film of the present invention. Examples of such commercially available products include Bonil Q manufactured by Kojin Film & Chemicals.

  The thickness of the resin intermediate layer in the laminated film of the present invention can be, for example, 5 μm or more or 10 μm or more, for example, 40 μm or less or 20 μm or less.

[Barrier layer and resin intermediate layer]
As described above, in the laminated film of the present invention, as the barrier layer, the laminated material supplied in a layered state in advance on one side or both sides of the base film is used as it is, and the base film is used as the resin intermediate layer. It may also serve as a role. Laminate materials that can be suitably used in such cases include, for example, polyvinylidene chloride coated / biaxially stretched nylon, polyvinylidene chloride coated / biaxially stretched polyethylene terephthalate, aluminum vapor deposited / polyethylene terephthalate, aluminum vapor deposited / biaxially stretched nylon. , Silica vapor deposition / biaxially stretched polyethylene terephthalate, silica vapor deposition / biaxially stretched nylon, polyvinyl alcohol / biaxially stretched polypropylene, polycarboxylic acid polymer / biaxially stretched nylon, metaxylenediamine-nylon composite film, ethylene vinyl alcohol copolymer Examples thereof include a coalescence-nylon composite film.

  Examples of these commercially available products include KBC manufactured by Kojin Film &Chemicals; KET-HB60 manufactured by Daicel Value Coating; BR1412 and BRON 7012 manufactured by Toray Film Processing Co., Ltd .; A-OP manufactured by Mitsui Chemicals Tosero; Emblet NV manufactured by Unitika, Emblem HGB; Super Neal SP-R, EH manufactured by Mitsubishi Plastics, and the like.

[Sealant layer]
The sealant layer in the laminated film of the present invention can be melted by friction caused by vibration during application of ultrasonic waves and fused to each other, and can preferably support the straight cut property of the outer layer, preferably further It is made of a heat-resistant material that can withstand retorting of the contents.

The sealant layer in the laminated film of the present invention has the following conditions (1) to (3):
(1) Young's modulus in the laminated film MD direction is 200 MPa or more,
(2) The film thickness is 2.5 times or less of the film thickness of the outer layer, and (3) The tear strength in the laminated film MD direction is 1N or more and 5N or less,
It is a requirement to satisfy all of the above.

  The sealant layer in the present invention is a relatively thin layer made of a relatively hard material. Because the sealant layer is a hard and thin layer, when sealing laminated films ultrasonically, vibration attenuation due to ultrasonic waves is suppressed and good foreign matter sealability is obtained, and the straight cut property of the outer layer is obstructed. It will be possible to support well without doing. That the sealant layer is a hard and thin layer is ensured by the above condition (1) Young's modulus and (2) the ratio of the outer layer to the film thickness.

  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 is preferably 225 MPa or more in the laminated film MD direction in order to suppress vibration attenuation due to ultrasonic waves and ensure good contaminant sealability and preferably support the straight cut property of the outer layer. Yes, more preferably 250 MPa or more. On the other hand, the Young's modulus in the direction of the laminated film MD of the sealant layer is preferably 750 MPa or less, more preferably 600 MPa or less, from the viewpoint of ensuring the formation of a strong seal by melting by friction.

  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.

  From the viewpoint of forming a strong seal by melting, the thickness of the sealant layer is preferably more than 15 μm, more preferably 20 μm or more. On the other hand, the thickness of the sealant layer is preferably 100 μm or less and preferably 75 μm or less from the viewpoint of suppressing the attenuation of vibration due to ultrasonic waves as much as possible and avoiding the obstruction of the straight cut property of the outer layer. More preferred.

  Regarding the thickness of the sealant layer, in addition to being within the above-mentioned recommended range, it is necessary to satisfy the above condition (2) film thickness to outer layer ratio. When the thickness of the sealant layer is 2.5 times or less than the thickness of the outer layer, the function can be favorably supported without obstructing the straight cut property of the outer layer. The thickness of the sealant layer may be 2.3 times or less or 2.0 times or less with respect to the film thickness of the outer layer. On the other hand, from the viewpoint of forming a sufficiently high seal, the thickness of the sealant layer is preferably 1.3 times or more, and 1.4 times or more or 1. It may be 5 times or more.

  The sealant layer in the present invention is further required to have (3) a tear strength in the direction of the laminated film MD of 1N or more and 5N or less. By satisfying this requirement, the resulting laminated film exhibits extremely high straight cut properties. It is not clear about the relationship between the tear strength in the MD direction in the sealant layer and the straight cut property in the laminated film. However, the present inventors presume as follows.

  When tearing the laminated film of the present invention, the tearing stress applied to the uniaxially stretched polypropylene film as the outer layer propagates to the sealant layer through the barrier layer and the resin intermediate layer, and the entire laminated film is torn, and the packaging bag Is cut. At this time, it is expected that the stretching direction of the uniaxially stretched polypropylene film defines the tearing direction of the entire film. And in the preferable aspect of this invention so that it may mention later, MD direction of the whole laminated | multilayer film corresponds with the extending | stretching direction of the said uniaxially stretched polypropylene film.

  Here, when the tear strength of the sealant layer is low, the tear direction in the sealant layer deviates from the MD direction of the laminated film and cuts in any direction, and the straight cut property of the packaging bag tends to be impaired. . This tendency is particularly remarkable when the direction of tearing stress is deviated from the MD direction of the laminated film. In this regard, when a sealant layer with high tear strength is used, the sealant layer alone is difficult to cut, so the direction in which the entire laminated film is cut is the direction defined by the uniaxially stretched polypropylene film (= MD direction of the laminated film) It depends on the cutting ability, and the inductivity in the tearing direction expected by the present invention can be maintained, so that it is considered that the straight cut performance is excellent.

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

  If the tear strength of the sealant layer is set to 1 N or more and 5 N or less in the laminated film MD direction, the effect of the present invention is considered to be due to the above reasons.

  The tear strength in the MD direction of the sealant layer may be 1.2 N or more, 1.5 N or more, or 3 N or less or 2.5 N or less.

  Since the sealant layer in the present invention has higher tear strength in the laminated film TD direction, tearing in an unexpected direction is limited, and therefore, the straight cut property is excellent. From such a viewpoint, the tear strength in the laminated film TD direction of the sealant layer is preferably 2.5 times or more, more preferably 3.0 times or more with respect to the tear strength in the MD direction. The ratio is more preferably 4.0 times or more, and particularly preferably 5.0 times or more. The upper limit may be 20 N or less or 15 N or less from the viewpoint of ease of manufacture and reproducibility.

  Any of the above tear strengths can be measured according to JIS K7128-1.

  When the tear strength 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.

  In addition to satisfying the above requirements, the sealant layer in the present invention 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 is more preferably 107.5 J / g or less, and still more preferably 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 is more preferably 50 J / g or more, and even more preferably 75 J / g or more.

  Specifically as a material of the sealant layer in the present invention, for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), 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, polybutene And the like. 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 invention may be a single layer or a multilayer as long as the above requirements are satisfied.

[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 invention is supposed 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. . 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. More preferably, printing is performed at the following locations.

When the laminated film has each layer in the order of the outer layer, the barrier layer, the resin intermediate layer, and the sealant layer: between the outer layer and the barrier layer, or between the barrier layer and the resin intermediate layer, the laminated film has each layer, the outer layer, and the resin When having an intermediate layer, barrier layer, and sealant layer in this order: between the outer layer and the resin intermediate layer, or between the resin intermediate layer and the barrier layer

  The printing can be performed by an appropriate printing method such as gravure printing or flexographic printing.

<Laminated film>
As described above, the laminated film of the present invention has an outer layer, a barrier layer, a resin intermediate layer, and a sealant layer. The laminated film of the present invention has the above-described layers in the order of the outer layer, the barrier layer, the resin intermediate layer, and the sealant layer; or the outer layer, the resin intermediate layer, the barrier layer, and the sealant layer in this order. The order of the outer layer, the resin intermediate layer, the barrier layer, and the sealant layer is preferable from the viewpoint of protecting the contents more reliably.

  As described above, the outer layer in the laminated film of the present invention may be a uniaxially stretched polypropylene film, and the resin intermediate layer may be a uniaxially stretched film or a biaxially stretched film. The sealant layer and the laminated film have an MD direction and a TD direction, respectively. In the laminated film of the present invention, it is preferable to appropriately set these directions from the viewpoint of effectively expressing a high degree of straight cut.

Most preferably in the laminated film of the present invention,
The stretching direction of the uniaxially stretched polypropylene film of the outer layer,
MD direction of the sealant layer,
Is preferable from the viewpoint of maximizing the effects of the present invention. When the resin intermediate layer is a uniaxially stretched body, it is preferable that the uniaxially stretched direction further coincides with the above direction. In the case where the resin intermediate layer is a biaxially stretched body, it is preferable that one of the biaxially stretched directions and the above-described direction are further matched.

It is preferable that each layer in the laminated film of the present invention 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.

  The thickness (total film thickness) of the laminated film of the present invention is preferably 150 μm or less from the viewpoint of realizing good ultrasonic sealing properties. The thickness of the laminated film is more preferably 120 μm or less, still more preferably 100 μm or less, and particularly preferably 90 μm or less. On the other hand, from the viewpoint of imparting practical geometric strength to the laminated film, the thickness of the laminated film is preferably 35 μm or more, more preferably 50 μm or more, and particularly preferably 60 μm or more.

  The tearability of the laminated film is related to the tear strength. It can be evaluated that the tearability of the laminated film is good when the tear strength of the laminated film measured in accordance with JIS K7128-1 is 0.60 N or less. Therefore, the tear strength measured with the above criteria for the laminated film of the present invention is preferably 0.60 N or less, more preferably 0.55 N or less, and more preferably 0.50 N or less. On the other hand, in order to avoid unexpected opening except when the user intends, the tear strength is preferably 0.20 N or more, and more preferably 0.30 N or more.

The bending rigidity of the laminated film of the present invention measured according to JIS K7118 is preferably 30 N · mm ² or more. This value is more preferably 40 N · mm ² or more, and still more preferably 50 N · mm ² or more. On the other hand, the flexural rigidity of the laminated film is preferably 150 N · mm ² MPa or less, more preferably 120 N · mm ² or less, and further preferably 100 N · mm ² or less. A packaging bag manufactured from a film having bending rigidity in this range is excellent in ultrasonic sealing properties, and is particularly preferable because it exhibits good foreign matter sealing properties by application of ultrasonic waves and also exhibits good straight-cut properties. .

  The laminated film of the present invention has excellent straight cut properties. For example, the straight cutting property is such that 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 is relative 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). A normal tear test is performed using this sample (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 the original opening direction is to the opening when stress is applied in a direction different from the originally intended opening direction. Aspiration suffocation of the eater when the food is highly viscous can be avoided. The angle can be 10 ° or less, and can be 9 ° 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 invention as described above 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 the present invention is excellent in ultrasonic sealing properties as described above, and in particular, is excellent in contaminant sealing properties due to application of ultrasonic waves. Therefore, the laminated film of the present invention is preferably used for bag filling with a sealing step by ultrasonic waves, and is preferably used for bag making with a foreign matter sealing step by ultrasonic waves. That is, it is preferable that the bag making method of the present invention includes a step of ultrasonically sealing the sealant layers of the laminated film.

  At the time of bag making, first, the laminated film of the present invention is opposed so that the sealant layers face each other, or folded, and two opposite sides or one side opposed to the folded portion is heat-sealed to face each other. It is set as the cylindrical molded object with which 2 sides to close are closed. In this molded body, the two closed sides constitute the bottom and top sides of the package.

  At this time, it is preferable to comprise so that the extending | stretching direction of the uniaxially stretched polypropylene of the outer layer of a laminated film may correspond with the opening direction of a cylindrical body. By adopting such a configuration, opening in the direction orthogonal to the height direction is facilitated in the obtained package, and the opening diameter does not greatly exceed the planned diameter, so the content is high-viscosity food. In the case of accidental aspiration suffocation of the eater can be avoided.

  Next, the above-mentioned normal molded body is mounted on a commercially available bag making machine equipped with an ultrasonic sealing device to make a bag. Here, using the bag making and filling machine for making bags while filling the contents as the bag making machine, it is advantageous to carry out bag making and filling in an embodiment in which the ultrasonic seal is a foreign matter seal. Is preferable in that is maximized.

  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 numerical value following “#” indicates the film thickness in μm.

<Evaluation of straight cut performance of laminated film>
[Examples 1 to 5 and Comparative Examples 1 to 7]
(1) Manufacture of laminated film K-Ny # 15 (polyvinylidene chloride coat (K coat) / biaxially stretched nylon film, manufactured by Kojin Film & Chemicals Co., Ltd., film thickness: 15 μm) is used as the barrier layer and the resin intermediate layer. A uniaxial PP (uniaxially stretched polypropylene film, manufactured by Phutamura Chemical Co., Ltd., film thickness: 20 μm (Examples 1 to 4 and Comparative Examples 1 to 7) or 25 μm (Example 5)) as an outer layer on the K coat side, a nylon film A laminated film is produced by dry laminating the LL (Linear Low Density Polyethylene) films listed in Table 2 on the side with a dry laminating adhesive (Rock Paint, "RU-50") interposed therebetween. did.

  When manufacturing the laminated film, one of the stretching directions in the biaxially stretched nylon film in K-Ny # 15, the stretching direction of the uniaxial PP, and the MD direction of the LL coincide with each other. Was the MD direction of the entire 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. A cut of about 75 mm was made on the center line of the test piece in the longitudinal direction, and it was torn at a speed of 1,000 mm / min using a tensile tester. Then, the angle between the straight line connecting the tear start point to the completion point and the film MD direction was examined (see FIG. 3). The results are shown in Table 2.

[Example 6]
As a barrier layer and a resin intermediate layer, instead of K-Ny # 15, barrier Ny # 15 (polycarboxylic acid polymer coat / biaxially stretched nylon film, manufactured by Unitika Ltd., product name “Emblem HGB”, film thickness: 15 μm) A laminated film was produced and evaluated in the same manner as in Example 4 except that it was used. The results are shown in Table 2.

[Comparative Example 8]
(1) Production of laminated film Uniaxial PP # 20 (film thickness: 20 μm) and LL (SE620L) (film thickness: 50 μm) on the nylon film side of K-Ny # 15, and dry laminate adhesive “RU-50” The laminated film was manufactured by interposing and dry laminating in this order. At this time, the relationship between the stretching directions between the respective layers and the relationship between these and the film MD direction were set according to Example 1 and the like.

(2) Evaluation of straight cut property The straight cut property was evaluated by the same method as Example 1 using the laminated film obtained above. The results are shown in Table 2.

[Comparative Example 9]
(1) Manufacture of laminated film Tear PET (PC) # 12 (polyethylene terephthalate film, manufactured by Unitika Ltd., product name “NCBC”, film thickness: 12 μm) on the K coat side of K-Ny # 15, and LL on the nylon film side (SE625L) (Linear low-density polyethylene film, manufactured by Tamapoly, product name “SE625L”, film thickness: 30 μm) are each laminated by dry lamination with a dry laminate adhesive “RU-50” interposed therebetween. Manufactured. At this time, the relationship between the stretching directions between the respective layers and the relationship between these and the film MD direction were set according to Example 1 and the like.

(2) Evaluation of straight cut property The straight cut property was evaluated by the same method as Example 1 using the laminated film obtained above. The results are shown in Table 2.

[Example 7 and Comparative Example 10]
(1) Manufacture of laminated film K-PET # 12 (polyvinylidene chloride coat (K coat) / biaxially stretched polyethylene terephthalate film, manufactured by Unitika Ltd., film thickness: 12 μm) was used as the barrier layer and the resin intermediate layer, and K coat. The uniaxial PP # 20 as the outer layer on the side and the LL (Linear Low Density Polyethylene) film listed in Table 2 on the polyethylene terephthalate film side are dry laminated with a dry laminate adhesive “RU-50” interposed therebetween, respectively. Thus, a laminated film was produced. At this time, the relationship between the stretching directions between the respective layers and the relationship between these and the film MD direction were set according to Example 1 and the like.

(2) Evaluation of straight cut property The straight cut property was evaluated by the same method as Example 1 using the laminated film obtained above. The results are shown in Table 2.

[Example 8]
(1) Manufacture of laminated film Aluminum foil # 7 (aluminum foil, manufactured by Toyo Aluminum Co., Ltd., product name “1N30”, film thickness: 7 μm) is used as a barrier layer, and dry laminate adhesive “RU-50” is applied to one side thereof. Ny # 15 (Nylon film, manufactured by Kojin Film & Chemicals Co., Ltd., product name “Bonyl Q”, film thickness: 15 μm) as a resin intermediate layer is dry-laminated and laminated with a barrier layer and a resin intermediate layer. A film was obtained.

  Dry laminate with uniaxial PP # 20 on the aluminum foil side of the laminated film and LL (SE625L) (film thickness: 30 μm) on the Ny # 15 side with a dry laminate adhesive “RU-50” interposed therebetween, respectively. Thus, a laminated film was produced. At this time, the relationship between the stretching directions between the respective layers and the relationship between these and the film MD direction were set according to Example 1 and the like.

(2) Evaluation of straight cut property The straight cut property was evaluated by the same method as Example 1 using the laminated film obtained above. The results are shown in Table 2.

[Example 9 and Comparative Example 11]
(1) Manufacture of laminated film Aluminum vapor deposition / PET # 12 (aluminum vapor deposition / polyethylene terephthalate film, manufactured by Toray Film Processing Co., Ltd., product name “BR1412”, film thickness: 12 μm) is used as the barrier layer and resin intermediate layer on the aluminum side. A laminated film is produced by dry laminating the outer layer film shown in Table 2 with LL (SE625L) (film thickness: 30 μm) on the polyethylene terephthalate side with a dry laminate adhesive “RU-50” interposed therebetween. did. At this time, the relationship between the stretching directions between the respective layers and the relationship between these and the film MD direction were set according to Example 1 and the like.

(2) Evaluation of straight cut property The straight cut property was evaluated by the same method as Example 1 using the laminated film obtained above. The results are shown in Table 2.

  From the results shown in Table 2, the following can be understood.

  It was found that even when the same kind of resin was used as the outer layer, the barrier layer, and the sealant layer, a difference appeared in the straight cut property of the laminated film depending on the tear strength of the sealant layer. In Comparative Examples 2 to 4 in which the tear strength in the MD direction of the sealant layer is smaller than the predetermined range of the present invention and Comparative Examples 5 and 6 in which the present invention is larger than the predetermined range of the present invention, the straight cut property of the laminated film is 12 °. The object of the present invention is not achieved. The same was true for Comparative Example 10.

  The Young's modulus of the sealant layer affects the straight cut property of the laminated film. In Comparative Examples 1, 2, 5, and 6 in which this value is smaller than the predetermined range of the present invention, the straight cut property of the obtained laminated film exceeded 12 °, and the object of the present invention was not achieved.

  The film thickness ratio between the outer layer and the sealant layer affects the straight cut property of the laminated film. Comparative Example 1 in which the ratio of the sealant layer thickness to the outer layer thickness (“film thickness to outer layer ratio” in the table) is smaller than the predetermined range of the present invention and Comparative Example 7 larger than the predetermined range of the present invention is laminated. The straight cut properties of the film exceeded 12 °, and the object of the present invention was not achieved.

  The stacking order of each layer affects the openability of the laminated film. The laminated film obtained in Comparative Example 8 in which the order of lamination of the barrier layer and the resin intermediate layer and the outer layer was changed showed excellent straight-cut properties, but the tear strength was very high, and the packaging bag was opened. It turned out to be inferior to

  Comparative Example 9 is an example in which a resin film excellent in MD straight cut property was used instead of the uniaxially stretched polypropylene film. Surprisingly, it was found that the obtained laminated film was inferior in the straight cut property intended by the present invention. Comparative Example 11 gave similar results.

  In contrast to the above, the outer layer composed of a uniaxially stretched polypropylene film, the barrier layer and the resin intermediate layer, and the sealant layer in this order, the Young's modulus of the sealant layer, the tear strength in the MD direction, and the thickness of the sealant layer The laminated films obtained in Examples 1 to 6 in which the outer layer ratio is within the predetermined range of the present invention can provide a packaging bag that is excellent in straight cut performance, has low tear strength, and can be opened comfortably. It was verified. Similar results were obtained for Examples 7 to 9 in which the material types of the barrier layer and the resin intermediate layer were changed.

<Evaluation of filled packaging bags>
Using the laminated films obtained in Example 4 and Comparative Examples 3 and 4, respectively, the jelly food (konjac-containing jelly confectionery) is used as a content to make a bag and fill it to produce a filled packaging bag. The straight-cut property was evaluated.

(1) Implementation of packaging and filling The procedure for filling and making bags will be described with reference to FIG.

  Two sheets of each laminated film 5 were set in a bag making and filling machine (Orihiro's “Onpack-VH100”) equipped with a longitudinal vibration ultrasonic sealing device in a state where the sealant layers were placed on the inner side. FIG. 2 (a)). These films are vertically long and become the height direction of the filled packaging bag in which the width direction of the film (direction orthogonal to the flow direction) is obtained.

  Both of the two widthwise end portions 12 of the two films 5 (the top portion and the bottom portion of the obtained filling and packaging bag) were heat-sealed to form a cylindrical body (FIG. 2B). Further, the bottom 13-1 of the cylindrical film (one side end portion of the resulting filled packaging bag) was ultrasonically sealed in a direction orthogonal to the flow direction to form a bag. This ultrasonic sealing was performed in an area of 65 mm width at an output of 300 J for 0.3 seconds.

  Thereafter, filling of the contents 11 from the nozzle 10 was started. When the filling of the contents 11 exceeds one portion, the portion 13-2 in FIG. 2D is ultrasonically sealed (contaminant seal) under the same conditions as above, and the contents 11 are put into the film. Sealed.

  Next, by cutting the center of the 13-2 ultrasonic seal portion, a filling packaging bag (pouch) 20 having a length of 110 mm, a width of 55 mm, and an opening length of 18 mm filled with 30 g of jelly food as the contents 11 is obtained. Manufactured.

(2) Evaluation of contaminant sealability The ultrasonic seal part (contaminant seal part) of the filled packaging bag obtained above was subjected to a T-type peel test in accordance with JIS K6854-3, and the contaminant seal strength ( Jelly).

(3) Evaluation of straight cut performance The above-mentioned pouch was opened so as to apply stress to an oblique angle of about 45 °, and the opening length of the opening was measured. The evaluation was performed by 10 testers per sample, 3 times for each person, and an average value of 30 times as the opening length.

  Here, the laminated film of the present invention is suitably used as a pouch for jelly food. As mentioned above, there is a danger of suffocation when jelly food gets stuck in the trachea of the eater. Here, the average diameter of an adult bronchus is 16.5 mmφ. When the opening length of the pouch is about 25 mm, the extrusion diameter of the pouch contents is 16.5 mmφ (25 mm × 2 × π≈16.5 mmφ), so when the opening length is 25 mm or less, straight cut When the opening length exceeded 25 mm, the straight cut property was evaluated as “bad”.

  The evaluation results are shown in Table 3.

DESCRIPTION OF SYMBOLS 1 Outer layer 2 Barrier layer 3 Resin intermediate layer 4 Sealant layer 5 Laminated film 10 Nozzle 11 Contents 12 Heat seal part 13 Ultrasonic seal part 13-1 Ultrasonic seal part (the 1)
13-2 Ultrasonic seal (Part 2)

Claims (7)

An outer layer made of uniaxially stretched polypropylene film;
Barrier layer and resin intermediate layer in any order,
A sealant layer,
In this order,
The sealant layer has the following conditions (1) to (3):
(1) Young's modulus in the laminated film MD direction is 200 MPa or more,
(2) The film thickness is 2.5 times or less of the film thickness of the outer layer, and (3) The tear strength in the laminated film MD direction is 1N or more and 5N or less,
The laminated film satisfying all of the above.   The laminated film according to claim 1, wherein the sealant layer is a linear low density polyethylene film.   The laminated film according to claim 1 or 2, wherein the tear strength in the MD direction of the sealant layer is 1N or more and 3N or less.   The packaging bag formed by sealing the sealant layers of the laminated | multilayer film as described in any one of Claims 1-3, and bag-making.   The packaging bag according to claim 4, wherein the seal is an ultrasonic contaminant seal.   The bag making method characterized by including the process of ultrasonically sealing the sealant layers of the laminated | multilayer film as described in any one of Claims 1-3. The ultrasonic sealing step is an ultrasonic contaminant sealing step.
The bag making method according to claim 6.

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