JPH07125756A - Easily tearable bag with zipper and production thereof - Google Patents

Abstract

PURPOSE:To provide an easily tearable bag with a zipper and the production method thereof, which can be easily torn and has linearly cutting characteristics and which is provided with a sufficient strength. CONSTITUTION:This bag is provided with the bag body 33 made of an easily tearable laminate film 32 formed as a layer made of a plurality of layers of an easily tearable film which includes 40-85 pts.wt. nylon 6(Ny6) and 15-60 pts.wt. of m-xylylene-adipamide(MXD6) (provided that Ny6+MXD6=100 pts.wt.) and in which both elongation ratios in the machine direction (direction of film movement) and the transverse direction (direction of film width) are made 2.8 or more and a zipper 21 attached at the opening of the bag body 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily tearable bag with an engaging device and a method for producing the easily tearable bag with an operating device, and can be used in the fields of foods, pharmaceuticals, sundries and the like.

[0002]

BACKGROUND ART In recent years, an occluding tool (chuck) has been provided in an opening part so that the contents can be used as a bag for foods, medicines, etc. in several times. Bags with articulators are available. Conventionally, a film that is often used as a seal base film for such a bag is a film of linear low-density polyethylene (L-LDPE) or the like. However, this L-LDPE film has an advantage that it is excellent in sealing strength and safe, but on the other hand, it has a large tear resistance, so that it cannot be cut straight along the cut line during use and there is a problem in opening.

For this reason, when opening the bag with the articulation device, when cutting the gap between the seal part on the upper part of the articulation device and the articulation device,
There was a practical inconvenience that it was not possible to cut it in a straight line by hand and it had to be cut using scissors. Conventionally,
In order to solve such problems, various proposals as described below have been made, but there is still no bag with an engaging device which is sufficiently satisfactory not only in terms of easy tearability but also in terms of production and strength. . For example, a bag with an occlusal device has been proposed which attempts to improve easy tearability by using a laminated film of a stretched nylon film and an L-LDPE film. However, the tear resistance is still large and it is difficult to cut, and the film is large at the time of tearing and tears at the crotch, so that it is often caught in the seal portion and cannot be opened any more.

There is also a construction in which a tape made of a uniaxially stretched film is stuck as an opening guide between the engaging device and the seal portion, but in this case, the cost is increased due to the use of the tape base material and the increase of the tape sticking process. It was In addition, there is a limitation in the speed of bag making, resulting in a decrease in productivity.
Further, although the straight line cutting property is good, a whisker-shaped cutting surface is formed in the tear portion, which is not preferable in appearance. A structure has been proposed in which minute scratches that serve as guides are formed on the surface base material between the engaging device and the seal portion to facilitate tearing, but even in this case, the linear cut property still depends on the properties of the base material film. It is apt to be performed, and as a result, sufficient straight line cutting property is not obtained. Moreover, even if it is fine, the surface of the bag will be scratched, and there will be some concern about strength. Therefore,
It is an object of the present invention to provide an easily tearable bag with an articulating device having excellent tearability and linear cuttability, and also having sufficient strength, and a method for producing the easily tearable bag with an engaging device. .

[0005]

Means and Actions for Solving the Problems An easily tearable bag with an engaging device according to the present invention comprises 40 to 85 parts by weight of nylon 6 (Ny6) and 15 to 15 parts of metaxylylene adipamide (MXD6).
Multiple easily tearable films containing 60 parts by weight (however, Ny6 + MXD6 = 100 parts by weight) and having a draw ratio of 2.8 times or more in both MD direction (film moving direction) and TD direction (film width direction) It is characterized by having a bag main body made of an easily tearable laminated film formed as one layer, and an engaging device provided at an opening portion of the bag main body.

[0006] In addition, the method for producing the easily tearable bag with the engaging device is as follows. A raw film containing 40 to 85 parts by weight of Ny6 and 15 to 60 parts by weight of MXD6 (however, Ny6 + MXD6 = 100 parts by weight) is used in the MD direction. And TD direction are both stretched at a magnification of 2.8 times or more to prepare an easily tearable film, and after making the easily tearable laminated film in which the easily tearable film is formed as a plurality of layers, the easily tearable laminate is prepared. It is characterized in that the film is provided with an articulating tool to make a bag. Ny6
The chemical formula of is shown in the following chemical formula 1.

[0007]

[Chemical 1]

The content ratio of Ny6 and MXD6 is N
y6 is 40 to 85 parts by weight, MXD6 is 15 to 60 parts by weight (however,
Ny6 + MXD6 = 100 parts by weight), preferably 50-80 parts by weight of Ny6 and 20-50 parts by weight of MXD6. When the amount of MXD6 is less than 15 parts by weight, the easy tearing property and the linear cutting property are deteriorated. Also, the MXD
When 6 is more than 60 parts by weight, the impact strength is significantly reduced and the practicality becomes poor.

The easily tearable film contains 40 to 85 parts by weight of Ny6 and 15 to 60 parts by weight of MXD6 (however, Ny6 + MX
D6 = 100 parts by weight) is mixed, the mixture is melt-extruded, and then the cooled raw film is stretched at a magnification of 2.8 times or more in both MD and TD. The stretching ratio of the raw film is 2.8 times or more in both MD and TD directions, and preferably 3.0 times or more. When the draw ratio is less than 2.8 times, the easy tearing property and the linear cutting property become poor. In addition, the impact strength is lowered, causing a problem in practical use.

The stretching is preferably carried out by simultaneous biaxial stretching by the tubular method. Incidentally, necessary additives can be appropriately added to the easily tearable film. Examples of such additives include anti-blocking agents (inorganic fillers, etc.), water repellents (ethylene bisstearate, etc.), and lubricants (calcium stearate, etc.).

The easily tearable laminated film may include any number of layers such as two layers, at least one layer including the easily tearable film. For example, a three-layer structure in which the first layer is various base material films, the second layer is the easily tearable film, and the third layer is various sealant films, the first layer is the easily tearable film, and the second layer is various bases. It can be configured as a material film, a three-layer structure in which the third layer is various sealant films, a first layer in the easily tearable film, and a two-layer structure in which the second layer is various sealant films.

Examples of the material for the base film include PET (polyethylene terephthalate), EVOH (saponified ethylene-vinyl acetate copolymer), PVA (polyvinyl alcohol), PP (polypropylene), PVD.
A biaxially or uniaxially stretched film such as C (polyvinylidene chloride), HDPE (high density polyethylene), PS (polystyrene) or a non-stretched film can be used. In addition to such a resin film, a metal film such as an aluminum foil may be used.

As the material of the sealant film,
L-LDPE (linear low density polyethylene), LDPE
(Low density polyethylene), HDPE (High density polyethylene), EVA (Ethylene-vinyl acetate copolymer), PB
(Polybutene-1), CPP (unstretched polypropylene), ionomer, PMMA (polymethylmethacrylate), etc. and mixtures thereof can be used.

As the laminating method of the easily tearable laminated film, there are, for example, extrusion laminating, hot melt laminating, dry laminating and wet laminating. The method for producing the above-mentioned engaging device is not particularly limited, and it can be usually produced by extrusion using an extrusion die having a shape corresponding to the cross-sectional shape of the engaging device and then cooling in water. The shape of the bite is not limited to the one provided with a male member and a female member that engage with each other, and may be any known shape as long as it can be opened and resealed.

The material of the engaging device is appropriately selected according to the material of the sealant film of the easily tearable laminated film. For example, if the sealant film is made of L-LDPE, the bite is also made of L-LDPE. Alternatively, if the sealant film is made of CPP, the bite is also made of PP. When making a bag,
It can be provided by heat-sealing the sealant film of the easily tearable laminated film using a known means such as heat, high frequency, or ultrasonic wave.

[0016]

Example 1 Nylon 6 (Ny6) and metaxylylene adipamide (MXD6) were mixed at a ratio of 60 parts by weight and 40 parts by weight, respectively, and melt-kneaded in an extruder at 270 ° C., The melt was extruded from a die having a diameter of 90 mm as a cylindrical film and then rapidly cooled with water to prepare a raw film. The one used as Ny6 is Ube Industries, Ltd.
Made of nylon 6 [UBE Nylon 1023 FD (trade name), relative viscosity η _r = 3.6], used as MXD6 is Mitsubishi Gas Chemical Co., Ltd. metaxylylene adipamide [MX nylon 6007 (trade name) ), Relative viscosity η _r = 2.7]
Is.

Next, as shown in FIG. 1, the raw film 11 is inserted between a pair of nip rolls 12 and then heated by a heater 13 while gas is being pressed into the nip rolls 12 and an air ring 14 is set at a stretching start point. More air 15 is blown to expand the bubbles 16, and the bubbles 16 are taken up by a pair of downstream nip rolls 17 to perform simultaneous biaxial stretching in the MD and TD directions by the tubular method. Magnification during this stretching is MD
It was 3.0 times in both the direction and the TD direction. Next, the biaxially stretched film 18 was placed in a tenter type heat treatment furnace and heat-set at 210 ° C. to obtain an easily tearable film according to this example.

Next, this easily tearable film (thickness: 15 μm)
The front substrate film, L-LDPE film [Unilux LS-722C (trade name), manufactured by Idemitsu Petrochemical Co., Ltd.,
With a thickness of 50 μm] as a sealant film, both were dry laminated to obtain an easily tearable laminated film. On the other hand, as shown in FIGS. 2 and 3, an L-LDPE occlusion device [Prolac LL200 (trade name), Prolac Co.] 21 was prepared. The bite 21 is composed of one male member 22 and the other female member 23.

The male member 22 is formed by integrally forming a belt-shaped continuous base portion 24 serving as a fusion-bonded portion, a heart-shaped head portion 25 in cross section, and a rod-shaped connecting portion 26 for connecting the two 24, 25. . Further, the female member 23 has a base portion 27 that is continuous in a band shape as a fusion-bonding portion, a semicircular first hook portion 28 formed on the base portion 27, and a base portion that faces the first hook portion 28.
The semi-circular second hook portion 29 formed on 27 is integrally molded. A gap 31 having a width substantially corresponding to the thickness of the connecting portion 26 is provided between the end edges 28A and 29A of the hook portions 28 and 29.

Next, as shown in FIG. 4, when the bag is made by the bag making machine, the easily tearable laminated film 32 and the occlusal tool 21 are fed out together, and the male member 22 and the female member 23 are made into the bag body 33. Easy-to-tear laminated film so that it is located in the opening part of
After heat-sealing to 32, the four sides of the bag body 33 were heat-sealed to obtain an easily tearable bag 34 with the engaging device 21 according to this example. When opening the easily tearable bag 34 with the bite, the seal portion 35 and the bite
When the space between 21 was torn by hand, a straight cut line 36 was obtained as shown in FIGS. Figure 5 shows the articulation device after this
The tearable bag 34 is shown with the 21 open.

With respect to the easily tearable bag 34 with the engaging device 21 according to this embodiment, the linear cut property and the tear resistance when the seal portion 35 and the engaging device 21 were torn by hand were evaluated. The evaluation results are shown in Table 1 below. The linear cut property is the sealing portion 35.
It was evaluated by measuring the amount of deviation when trying to make a straight cut between the and the occlusion device 21 (10 mm). The evaluation standard is ◎ when the deviation amount is within 5 mm, ○ when the deviation amount is within 10 mm, × when the deviation amount exceeds 10 mm, and when the seal part or the chuck part is contacted in the middle, × And
The tear resistance was evaluated as follows: ○ when the resistance was small and cut smoothly until the end, and “X” when the resistance was large and the resistance stopped halfway.

A comprehensive evaluation was also performed on the basis of the evaluations of the linear cutting property and the tear resistance. In the overall evaluation, a very good bag was marked with ⊚, a good bag was marked with ◯, and a bag having a problem in use was marked with x. Also, an easy tear bag with this bite 21
When a drop test was performed on 34, no bag was broken,
It was confirmed that it had sufficient strength. In this drop test, an easily tearable bag 34 (130 mm × 150 mm) with an engaging device containing 150 cc of an equal amount of liquid mixture of water and antifreeze is placed from the height of 2 m with the bag sideways, that is, the front and back surfaces of the bag are the drop points. It was carried out by dropping 20 times in one bag so as to be parallel to and checking whether or not the bag was broken. The test temperature was -20 ° C.

Examples 2 to 9 In the same manner as in Example 1 above, an easily tearable laminated film
32 was obtained, and using the easily tearable laminated film 32, the easily tearable bag 34 with the engaging device 21 according to each example was produced. However, the layer structure of the easily tearable laminated film 32 according to each example is as shown in Table 1. The stretch ratio of the easily tearable film of each example is 3. in both MD and TD.
It is 0 times. In the column of “Layer structure of laminated film” in the table, the film means a base film and the sealant means a sealant film.

In the column of "Laminate film layer structure", LL is linear low-density polyethylene, PET is polyethylene terephthalate, ONy is biaxially oriented nylon,
OPP is biaxially oriented polypropylene, EVA is ethylene-
Vinyl acetate copolymer and KONy mean biaxially stretched nylon coated with vinylidene chloride resin. In the column of "easily tearable film", "part" means "part by weight". Then, with respect to the easily tearable bag 34 with the engaging device 21 of each example, in the same manner as in Example 1, the linear cutability and the tear resistance when manually tearing between the seal portion 35 and the engaging device 21 were evaluated. A comprehensive evaluation was also conducted. The evaluation results are shown in Table 1 below. A drop test was performed on the easily tearable bag 34 with the engaging device 21 of each example in the same manner as in Example 1, and it was found that the bag did not break and there was no problem.

Comparative Examples 1 to 4 Laminate films were obtained in the same manner as in Example 1 above.
Using this laminated film, a bag with an engaging device according to each comparative example was produced. However, the layer structure of the laminate film according to each comparative example is as shown in Table 1. And
With respect to the bag with an engaging device of each comparative example, in the same manner as in Example 1, the linear cuttability and the tear resistance when tearing between the seal portion and the engaging device by hand were evaluated. A comprehensive evaluation was also conducted.
The evaluation results are shown in Table 1 below. In addition, when the bag with an engaging device of each comparative example was subjected to the drop test in the same manner as in Example 1, the bag was broken, and there were practical problems.

[0026]

[Table 1]

From Table 1, the easily tearable bag 34 with the engaging device 21 according to the embodiment has 60 to 80 parts by weight of Ny6 and 20 to 40 of MXD6.
Includes parts by weight and stretch ratios in both MD and TD
The easily tearable film made to be 3.0 times has a bag main body made of an easily tearable laminated film formed as one layer of a two-layer structure or a three-layer structure, and an engaging device provided at the opening portion of the bag main body. Since it is a thing, it has a good straight line cutting property and can be cut substantially straight.

Further, it has a small tear resistance and is easy to tear. Further, it does not break in the drop test and has sufficient strength. On the other hand, in the bag with an engaging device according to the comparative example, since the easily tearable film according to the present invention is not formed in the laminate film, the linear cutting property is poor and the bag cannot be cut straight. Further, it has a large tear resistance and is inferior in easy tearability. Further, the bag was broken in the drop test, and the strength was poor.

[0029]

EFFECTS OF THE INVENTION According to the present invention, an easily tearable bag with an engaging device which has excellent tearability and linear cuttability and also has sufficient strength can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a biaxial stretching device used in the production of an easily tearable film according to an example of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a male member and a female member of an articulation tool used in an embodiment of the present invention are separated.

FIG. 3 is a cross-sectional view showing a fitting state of the occlusion device of the present embodiment.

FIG. 4 is a front view of an easily tearable bag with an engaging device according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of an easily tearable bag with an engaging device according to the present embodiment in an opened state.

[Explanation of symbols]

 11 Original film 18 Biaxially stretched film 11 Coupling device 12 Male member 13 Female member 24,27 Base 32 Easy tearing laminated film 33 Bag body 34 Easy tearing bag with engaging device

Claims (2)

[Claims] 1. Containing 40 to 85 parts by weight of nylon 6 (Ny6) and 15 to 60 parts by weight of metaxylylene adipamide (MXD6) (however, Ny6 + MXD6 = 100 parts by weight), M
A bag made of an easily tearable laminated film in which an easily tearable film having a draw ratio of 2.8 times or more in both the D direction (the moving direction of the film) and the TD direction (the width direction of the film) is formed as one layer of a plurality of layers. An easily tearable bag with an engaging device, comprising a main body and an engaging device provided at an opening portion of the bag main body. 2. A raw film containing 40 to 85 parts by weight of nylon 6 (Ny6) and 15 to 60 parts by weight of metaxylylene adipamide (MXD6) (however, Ny6 + MXD6 = 100 parts by weight) in the MD direction ( Film moving direction) and TD
In both directions (width direction of the film), stretchable at a magnification of 2.8 times or more to prepare an easily tearable film, and after making the easily tearable laminated film in which this easily tearable film is formed as one layer, A method for producing an easily tearable bag with an engaging device, which comprises providing an easily tearable laminated film with an engaging device to make a bag.