JPH0930559A - Packaging material excellent in tear properties and pouch by use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material which can be torn straight and neatly, and provide a pouch made of this material, in a packaging material laminated with oriented nylon film and tearable polypropylene film. SOLUTION: In a packaging material 1 laminated with oriented nylon film 2, tearable polypropylene film 3, and linear low density polyethylene film 4 in this order, the relation of the adhesive strength A between the oriented nylon film 2 and the tearable polypropylene film 3 and the adhesive strength B between the tearable polypropylene film 3 and the linear low density polyethylene film 4 are set to be B-250<=A<=B+50g/15mm width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material mainly composed of a plastic film, which has improved tearability, and a pouch using the packaging material.

[0002]

2. Description of the Related Art Toiletry products such as shampoos, rinses and kitchen detergents are sold in plastic bottles. In recent years, for the purpose of effective use of resources and reduction of volume of waste, the contents are packed in pouches and sold for refilling.

Such a pouch for refilling is for the user to transfer the contents to an empty bottle which has been opened by tearing or the like, and it is preferable that the pouch can be opened without using scissors or the like. Therefore, conventionally, the pouches used for the above-mentioned applications have been devised in various ways for imparting tearability. For example, there are known means such as perforating or half-cutting a packaging material, including a tearable film in the layer structure of the packaging material, devising a pouch shape or a heat-sealing shape.

Among the above-mentioned means, the technique of perforating and half-cutting is disadvantageous in terms of cost because the pouch manufacturing process is increased. Further, the method of devising the shape of the pouch and the shape of the heat seal is not a fundamental solution for tearability, and is meaningful only when the packaging material has a certain degree of tearability.

On the other hand, according to the method of using the tearable film in the layer constitution of the packaging material, a fundamental improvement in tearability can be expected.

[0006]

[Problems to be Solved by the Invention] Conventionally, packaging materials using a tearable film have been proposed. When the content is a relatively heavy material such as a liquid material, it is common to use a stretched nylon film as the base material of the packaging material so as to withstand the impact when the pouch is dropped. .

However, the pouch made of the packaging material using the stretched nylon film may not be cut straight and neatly at the time of tearing. When the cause of this was examined, the orientation of the stretched nylon film was not linear, but was a gentle arc, so the orientation direction was different on the front and back of the pouch, and therefore the break due to tearing was different on the front and back of the pouch. It turned out to be.

[0008] Therefore, the present invention is a packaging material in which the above stretched nylon film is further laminated with a tearable film, and a packaging material in which tearing is performed straight and beautifully, and excellent tearability using this packaging material. The purpose is to provide a pouch.

[0009]

Means for Solving the Problems That is, the present invention is a packaging material obtained by laminating a stretched nylon film, a tearable polypropylene film, and a linear low-density polyethylene film in this order, which comprises a stretched nylon film and a tearable polypropylene film. The adhesive strength A between the two and the adhesive strength B between the tearable polypropylene film and the linear low-density polyethylene film are in the range of the following formula, which is a packaging material excellent in tearability. . Formula B-250 ≦ A ≦ B + 50 (g / 15mm width)

The adhesive strength between the tearable polypropylene film and the linear low density polyethylene film is
The width is preferably 400 to 800 g / 15 mm. The stretch ratio of the tearable polypropylene film is
It is preferably within 5 times. The pouch of the present invention is produced by using the above packaging material, in which the orientation direction of the tearable polypropylene film is aligned with the tear opening direction of the pouch.

The packaging material of the present invention has a three-layer structure,
Since the adhesive strength between the layers is as described above,
Even if the orientation direction of the stretched nylon film is slightly misaligned,
Since the adhesive strength of each layer is well balanced, it is torn straight. And since the pouch of the present invention is formed so that the orientation direction of the tearable film coincides with the tear opening direction of the pouch, the tearability of the packaging material itself as described above causes a straight line when opened. It is torn and opened.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the packaging material of the present invention.

The packaging material 1 of the present invention comprises a stretched nylon film 2, a tearable polypropylene film 3 and a linear low density polyethylene film 4 laminated in this order.

The stretched nylon film 2 imparts impact resistance to the packaging material 1 as described above, and a commercially available stretched nylon film is optionally used. However, it is preferable that the stretched nylon film 2 has little orientation and excellent tearability. It is preferable to use one. Specifically, "Uniathlon" (trade name) manufactured by Idemitsu Petrochemical Co., Ltd. can be preferably used.

The tearable polypropylene film 3 is
Tearability is imparted to the packaging material 1, which is a film uniaxially stretched. The stretching ratio of the film is not particularly limited, but it is preferably 3 times or more in order to obtain sufficient tearability, and when the stretching ratio is too large,
The adhesive strength with the stretched nylon film 2 and the linear low density polyethylene 3 is not obtained. Therefore, the preferred stretch ratio is 5 to
6 times. A tear film made of polyethylene (uniaxially stretched polyethylene film) is also known as a tear film, but this film has poor heat resistance, and the tearability of the part is reduced due to heat sealing when molding into a pouch. To do. Therefore, in the present invention, a polypropylene product having excellent heat resistance is used. Examples of preferable tearable polypropylene film include those uniaxially stretched by rolling, and PG (trade name) manufactured by Mitsui Toatsu Co., Ltd. is known as a commercial product.

The linear low density polyethylene film 4 is formed as a heat seal layer of a packaging material.
In general packaging materials, in addition to the linear low-density polyethylene as the sealant layer, a film made of polyethylene, unstretched polypropylene, ethylene-vinyl acetate copolymer or the like is used, but in the present invention, low-temperature sealability The linear low-density polyethylene is used because it has less damage and does not easily break when dropped, and has excellent resistance to contents such as detergent.

Although the thickness of each film is arbitrary, it is generally preferable that the stretched nylon film 2 has a thickness of 13 to 17 μm, the tearable polypropylene film 3 has a thickness of 20 to 30 μm, and the linear low density polyethylene 4 has a thickness of 80 to 120 μm. .

In the packaging material 1 of the present invention described above, the above films are laminated by a dry laminating method using the adhesive 6. The packaging material 1 of the present invention is characterized in that the adhesive strength between the layers is made to have the above-mentioned relationship. That is, the adhesive strength A between the stretched nylon film 2 and the tearable polypropylene film 3 and the adhesive strength B between the tearable polypropylene film and the linear low-density polyethylene film are set within the ranges of the following formulas. To do. Formula B-250 ≦ A ≦ B + 50 (g / 15mm width)

Such an adhesive strength can be achieved by appropriately selecting and combining the following elements. Adhesive selection Treatment for improving the adhesive strength of the laminated surface of each film (corona discharge treatment, flame treatment, ozone treatment, anchor coat treatment, etc.) (Generally, these treatments improve the adhesive strength) Draw ratio of tearable polypropylene film (Generally, the higher the draw ratio, the lower the adhesive strength)

The packaging material 1 of the present invention having the above-mentioned structure
A printing layer 5 for displaying characters, patterns, etc. can be provided on the. In the illustrated embodiment, the printing layer 5 is formed on the inner surface side of the stretched nylon film 2 (between the stretched nylon film 2 and the tearable polypropylene film 3), but may be changed or added to any position as necessary. Of course, you can

The packaging material 1 of the present invention obtained as described above.
Pouch 1 by the method using a normal heat seal.
The bag can be made into 0 shape. At this time, for the purpose of the present invention, it is necessary to align the orientation direction of the tearable polypropylene film 3 with the tear opening direction of the pouch.

The shape of the pouch 10 is arbitrary, and examples thereof include a three-sided seal bag, a four-sided seal bag, a standing pouch, an envelope sticking bag, a pillow packaging bag, and a gusset bag, but as a trigger for opening, a seal is used. It is preferable to provide an I notch, a V notch, or other known means in the portion. For this purpose, it is preferable that the pouch is provided with a seal portion at an edge portion in the opening direction so as to extend at least partially, preferably in a direction perpendicular to the opening direction.

FIG. 2 shows an example of a pouch 10 according to the present invention, in which two of the above-mentioned packaging materials 1 are piled up, and a laminated material having the same structure as that of the packaging material is formed in the bottom portion of the pouch 10. This is a so-called standing pouch obtained by heat-sealing the periphery of the folded bottom member 12 (FIG. 2 (a)). In this pouch 10, the orientation direction of the tearable polypropylene film of the packaging material 1 is arranged so as to be a direction orthogonal to the side edge seal portion 14, that is, a lateral direction. Therefore, the pouch 10 can be torn in the lateral direction of the drawing. An I notch 16 is formed on the edge of the side edge seal portion 14 along the tearing direction. The opening 18 of the pouch is heat-sealed and sealed after the contents are filled. In the illustrated embodiment, in order to facilitate the pouring at the time of refilling, a heat-sealing shape is formed so that the spout 20 having a narrow width is formed when the pouch is torn and opened (FIG. 2 ( b)).

In the above-mentioned embodiment, the bottom member 12 is made of a laminated material having the same structure as the packaging material 1 of the present invention. However, since the bottom member does not need to be tearable, the conventionally used material is used. It can be used arbitrarily. Generally, the bottom member of the standing pouch is required to have impact resistance, and therefore it is preferable to use a laminated material containing a nylon film.

[0025]

EXAMPLES The following is an experiment on the packaging material of the present invention. The following materials were prepared as a stretched nylon film, a tearable polypropylene film, and a sealant film. By combining these, a packaging material having the following constitution was obtained.

<Prepared materials> -Stretched nylon film (2 types) -Product name: Uniathlon (manufactured by Idemitsu Petrochemical Co., Ltd.),
Biaxial stretching (stretching ratio: 8 times in the longitudinal direction, 3 times in the lateral direction), 15
μm ・ Brand name: ONYBC (manufactured by Unitika Ltd.), biaxially stretched (stretching ratio: 6 times in the longitudinal direction, 3 times in the lateral direction), 15 μm ・ Tearable polypropylene film (2 types) ・ Brand name: PG (Nisseki Plast Co., Ltd., uniaxial stretching (stretching ratio: 5 times), 25 μm (one side corona discharge treated, treated surface: 40 dyne / cm (surface wetting index, the same below), untreated surface: 37 dyne / cm) ・ Product name: Hybron ASC (Mitsui Toatsu Co., Ltd.),
Uniaxially stretched (stretching ratio: 8 times), 25 μm (both sides corona discharge treated, treated surface: 40 dyne / cm) -Sealant film (2 types) -Brand name: LC205C (Tama Poly Co., linear low density polyethylene), 130 μm ・ Product name: UC7C (Tama Poly Co., Ltd., linear low density polyethylene?), 130 μm

<Prepared packaging material> No. 1: Uniathlon / PG (process) / LC205C No. 2: Uniathlon / (process) PG / LC205C No. 3: Uniathlon / (process) PG + Corona / LC205
C No.4: ONYBC / PG (process) / LC205C No.5: ONYBC / (process) PG / LC205C No.6: ONYBC / (process) PG + Corona / LC205
C No.7: Uniathlon / PG (Process) / UC7C No.8: Uniathlon / ASC / UC7C

Here, No. 3 and No. 6 are obtained by subjecting the untreated surface of the polypropylene film to corona discharge treatment (surface wetting index after treatment: 41 dyne / cm). No.1
No. 3 was laminated using A515 (manufactured by Takeda Pharmaceutical Co., Ltd.) as an adhesive for dry lamination, and LX901 (manufactured by Dainippon Ink and Chemicals Co., Ltd.) for the others. When the adhesive strength between the layers of these packaging materials was created, it was as shown in Table 1.

A standing pouch (size 28 × 13 cm, capacity 700 ml) having the shape shown in FIG. 2 was prepared using this packaging material, filled with 700 ml of water, sealed, and stored at 5 ° C. for 1 day. It was dropped vertically from a height of 1.2 m up to 10 times, and the presence or absence of bag breakage was observed.
As the bottom member, an unstretched nylon film 15μ
A material having a structure of m / linear low-density polyethylene 130 μm was used. In addition, the pouch was opened and the deviation of the front and back of the tear was observed. The results are shown in Table 1.

[0030]

[Table 1]

As is clear from the above results, the adhesive strength between the tearable polypropylene film / linear low-density polyethylene film is large (No. 1, No. 4, No. 7).
Has a large amount of deviation at the time of tearing. Further, No. 8 using a polypropylene film having a large draw ratio satisfies the deviation amount but is inferior in bag breaking strength. On the other hand, those satisfying the configuration of the present invention (No. 2, No. 3, No. 5, No. 6) are:
Both the deviation amount and the bag breaking strength are satisfied.

[0032]

The packaging material of the present invention has the above-mentioned constitution, and has a simple constitution in which three films are laminated, which is very advantageous in terms of cost. Since the packaging material of the present invention has the above-mentioned constitution, it is excellent in tearing property in the opening direction, and tearing is performed straight and neatly.

[Brief description of drawings]

FIG. 1 is a sectional view showing one embodiment of a packaging material of the present invention.

FIG. 2 is an explanatory plan view showing an example of a pouch according to the present invention, (a) shows a pouch before filling contents, and (b) shows a state in which contents are filled and sealed.

[Explanation of symbols]

 1 ... Packaging material 2 ... Stretched nylon film 3 ... Tearable polypropylene film 4 ... Linear low-density polyethylene film 5 ... Printing layer 6 ... Adhesive 10 ... Pouch 12 ... Bottom member 14 ... Side edge seal part 16 ... I notch 18 ... Opening 20 ... Spout

Claims (4)

[Claims] 1. A packaging material in which a stretched nylon film, a tearable polypropylene film and a linear low density polyethylene film are laminated in this order, and has an adhesive strength A between the stretched nylon film and the tearable polypropylene film and a tearability. Adhesive strength B between a polypropylene film and a linear low-density polyethylene film is within the range of the following formula: A packaging material with excellent tearability. Formula B-250 ≦ A ≦ B + 50 (g / 15mm width) 2. The adhesive strength between the tearable polypropylene film and the linear low density polyethylene film is 40.
The packaging material according to claim 1, which has a width of 0 to 800 g / 15 mm. 3. The packaging material according to claim 1, wherein the tearable polypropylene film has a draw ratio of 6 times or less. 4. A pouch made using the packaging material according to any one of claims 1 to 3, wherein the orientation direction of the tearable polypropylene film is aligned with the tear opening direction of the pouch. A pouch that is easy to tear and open.