JPH0655714A - Laminated packaging material - Google Patents

Abstract

PURPOSE:To make it possible to tear off a laminated packaging material linearly by hands without providing further a stretched polyethylene layer having excellent linear cut properties or an unpacking assist member, in regard to the laminated packaging material using a nylon film having an excellent impact resistance. CONSTITUTION:In regard to a laminated packaging material prepared by laminating a nylon film 1 and a heat-sealing resin layer 2 sequentially, a biaxially stretched film constituted of aromatic polyamide and 6-nylon is used as the nylon film 1. An outer layer may be laminated on the surface of the nylon film on the opposite side to the heat-sealing resin layer. It is preferable, besides, that a gas barrier layer is provided between the nylon film 1 and the outer layer or the heat-sealing resin layer 2. These layers are laminated preferably by a dry lamination method using a bonding agent of urethane series.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated packaging material suitable for a flat bag, a standing pouch, etc., which has a tearability and can be linearly torn by hand.

[0002]

2. Description of the Related Art Conventionally, flat bags and standing pouches have been widely used as packages for liquid foods such as orange juice and fine powders. As packaging materials for such flat bags and standing pouches, A material containing a highly rigid nylon film is used in order to improve the impact resistance and the standing property of the package. The following layer structures of such materials are known: ONy / LLDPE; PET (or OPP) / Al foil / ONy / LLDPE;
Alternatively, PET (or OPP) / ONy / Al foil / LLDPE.

Here, ONy is a biaxially stretched 6- or 6,6-nylon film, LLDPE is linear low density polyethylene, PET is polyethylene terephthalate, and OPP is a biaxially stretched polypropylene film. And Al foil indicates aluminum foil.

However, when the conventional laminated packaging material having such a nylon film is used as a packaging body such as a flat bag or a standing pouch by heat-sealing the LLDPE inside, when taking out the contents. There was a problem that it was very difficult to tear it straight by hand. For example, when a package formed of a packaging material having a composition of ONy / LLDPE is torn in the lateral direction, a deviation of several mm occurs from the linear direction on the front side of the tear at the tear end of the package, and the back side Then 3
There has been a problem that a deviation of 0 to 40 mm occurs.

For this reason, scissors or a knife is used for opening, or a stretched polyethylene layer having excellent linear cut property is provided between ONy and LLDPE so that it can be torn linearly by hand. Are further laminated. Alternatively, it has been proposed to provide an unsealing auxiliary member made of a stretched film in a tearing direction at a portion to be unsealed on the outer surface of the package, that is, a portion to be torn by hand (Japanese Patent Publication No. 53-12216).

[0006]

However, if a stretched polyethylene layer is further formed between ONy and LLDPE in order to tear it linearly by hand without using scissors, the number of manufacturing steps is increased. However, there has been a problem that the manufacturing cost of the laminated packaging material increases due to the increase in the number of products. Further, the provision of the unsealing auxiliary member not only increases the manufacturing cost of the package, but also impairs its aesthetic appearance.

The present invention is intended to solve the above-mentioned problems of the prior art, and in a laminated packaging material using a nylon film having excellent impact resistance, a stretched polyethylene layer having a good linear cut property and an unsealing property. The purpose of the present invention is to make it possible to tear linearly by hand without further providing an auxiliary member.

[0008]

The present inventors have described the above by using a biaxially oriented film of a polymer blend of an aromatic polyamide and 6-nylon instead of a 6- or 6,6-nylon film. The inventors have found that the above object can be achieved, and have completed the present invention.

That is, according to the present invention, in a laminated packaging material in which a nylon film and a heat-sealing resin layer are sequentially laminated, the nylon film comprises an aromatic polyamide and 6-
Provided is a laminated packaging material, which is a film that is biaxially stretched after kneading with nylon.

The present invention will be described below in detail with reference to the drawings. Note that the same numbers in the drawings indicate the same or equivalent components.

FIG. 1 is a sectional view of the laminated packaging material of the present invention. As shown in the figure, the laminated packaging material of the present invention comprises a nylon film 1 and a heat-sealable resin layer 2 laminated thereon.

In the present invention, the nylon film 1 is, as described above, a film composed of an aromatic polyamide and 6-nylon, preferably a film produced by kneading an aromatic polyamide and 6-nylon. To use. In this case, it is necessary to use a biaxially stretched film, which results in tearability (linear cutability).
Can be improved. Also in the case of biaxial stretching, it is preferable to perform biaxial stretching by an extrusion tubular method that can impart uniform tearability in the width direction.

Further, since this nylon film 1 has a rigidity which is about 50% higher than that of the conventional 6- or 6,6-nylon film, it is possible to realize a standing pouch having an excellent standing (self-standing) property. .

Such an aromatic polyamide can be selected from various aromatic polyamides depending on the purpose of use. For example, a semi-aromatic polyamide obtained by polycondensing metaxylene diamine and adipic acid can be preferably used. The compounding ratio of the aromatic polyamide and the 6-nylon varies depending on the kind of the aromatic polyamide used and the like, but the tearability and the conventional 6- or
Aromatic polyamide is 10 to 90 in terms of achieving both impact resistance equivalent to that of 6,6-nylon film.
% By weight, preferably 40 to 60% by weight, 90 to 10% by weight of 6-nylon, preferably 60 to 40% by weight
Is.

The thickness of the nylon film 1 can be appropriately determined according to the purpose of use.

The heat-sealable resin layer 2 can be made of the same material as that conventionally used as a sealant layer for packaging materials, such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer,
An ionomer or the like can be used. Moreover, the thickness of the heat-sealable resin layer 2 is not particularly limited, and can be appropriately determined as necessary.

In the present invention, as shown in FIG.
Nylon film 1 on the side opposite to the heat-sealable resin layer 2
It is preferable that the outer layer 3 which is an outer layer than the nylon film 1 as a package is laminated on the surface of the. The rigidity can be increased by stacking the outer layer 3.
The outer layer 3 is preferably made of a flexible resin film such as polyethylene, polypropylene, polyester, nylon having excellent printability, preferably a polyethylene terephthalate film or a biaxially oriented polypropylene film. The thickness of the outer layer 3 is not particularly limited and can be appropriately selected according to the purpose of use.

In the present invention, as shown in FIG. 3 (a) or (b), the gas barrier layer 4 is provided between the nylon film 1 and the outer layer 3 or the heat-sealable resin layer 2.
Can be provided. As a result, oxygen and water vapor can be efficiently blocked, and the deterioration of the contents can be prevented. As a material forming such a gas barrier layer 4, a material which has been conventionally used for imparting a gas barrier property to a packaging material can be used.
For example, aluminum foil, polyvinylidene chloride, silicon oxide and the like can be preferably used.

The layer thickness of the Cass barrier layer is not particularly limited and can be appropriately determined according to the purpose of use.

The laminated packaging material of the present invention can be manufactured by a conventional method. For example, dry laminating method,
It can be manufactured by a non-solvent laminating method, an extrusion lamination method, a neel lamination method, a wet lamination method, a hot melt lamination method, or the like, or by laminating each layer by combining these methods. Among them, the dry laminating method, the non-solvent laminating method, the extrusion lamination method, and the nilam lamination method are preferable, and in this case, the urethane adhesive is 0.5 to 10 g / m ² (dry), preferably 1.0 to 5 g. When used in an amount of / m ² (dry), the tearability can be further improved. This is because the adhesive layer made of the urethane-based adhesive does not easily stretch, and thus it is easy to follow the tearing of the packaging material. Therefore, it is preferable to bond at least one of the layers with a urethane adhesive.

When silicon oxide is laminated as the gas Bayer layer 4, it can be carried out by a general vacuum deposition method, an ion plating method, a sputtering method, a plasma deposition method, a CVD method or the like, but it is preferable. It is formed by the vacuum deposition method, which has a great cost advantage.

The laminated packaging material thus obtained can be processed into the same standing pouch as in the conventional case.

[0023]

The laminated packaging material of the present invention has a biaxially stretched film composed of an aromatic polyamide and 6-nylon as part of its layer structure, so that it can be torn linearly by hand.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 6-nylon was added to aromatic polyamide obtained by polycondensation of metaxylenediamine and adipic acid, and the mixture was placed on a nylon film (made by Idemitsu Petrochemical Co., Ltd.) having a thickness of 15 μm and biaxially stretched. , A polyurethane-based adhesive (trade name; ADCORT AD308A / B: manufactured by Toyo Morton Co., Ltd.) at 3 g / m ² and a low-density polyethylene film having a thickness of 50 μm (trade name; LS722C: Idemitsu Petroleum) (Chemical Co., Ltd.) was laminated by a dry lamination method to produce the laminated packaging material of the present invention.

When the obtained packaging material was torn by hand, the deviation from the linear direction was 0 to 3 on the front side of the tear.
Can be pressed within mm, and 0 to 5 m on the back side
It could be held down to m, and showed excellent tearability (straight cut property).

Comparative Example 1 A laminated packaging material was manufactured in the same manner as in Example 1 except that a 6-nylon biaxially stretched film (trade name; Emblem RT: manufactured by Idemitsu Petrochemical Co., Ltd.) was used as the nylon film. A tearability test was performed on the obtained packaging material in the same manner as in Example 1. As a result, at the tearing end, the deviation from the linear direction was 0 to 3 on the front side of the tearing.
I was able to hold it within mm, but on the back side it was 3 at maximum.
A deviation of 8 mm occurred.

Example 2 A polyurethane adhesive (trade name; LX63F / KP-9) having a thickness of 12 μm on a biaxially stretched polyethylene terephthalate film (trade name; P-60, manufactured by Toray Industries, Inc.) was used.
0: made by Dainippon Ink and Chemicals, Inc.) 3.5 g / m
^The same nylon film as used in Example 1 was laminated by the dry lamination method,
A laminated packaging material of the present invention was produced by laminating low density polyethylene films in the same manner as in Example 1.

When the packaging material obtained was torn by hand, the deviation from the straight line direction at the end of tearing can be suppressed within 0 to 3 mm at the front end of the tearing, and also at the back side to 0 to 5 mm. And showed excellent tearability (straight cut property). Moreover, since the laminated packaging material of this example further had the polyethylene terephthalate layer, the overall rigidity was improved, and its standing property was improved.

Example 3 Between the polyethylene terephthalate film and the nylon film, a polyurethane adhesive (trade name: A515) was used.
/ A-50: Takeda Pharmaceutical Co., Ltd.) 9 μm
The laminated packaging material of the present invention was produced by repeating Example 2 except that thick aluminum foil was laminated.

When the obtained packaging material was torn by hand, at the end of tearing, the deviation from the linear direction on the front side of the tearing can be suppressed within 0 to 3 mm, and also on the back side to 0 to 5 mm. And showed excellent tearability (straight cut property). Moreover, since the laminated packaging material of this example further had the polyethylene terephthalate layer, the overall rigidity was improved, and its standing property was improved. In addition, since it has a layer of aluminum foil, it was excellent in oxygen and water vapor barrier properties.

Example 4 Between the heat sealable resin layer and the nylon film, a polyurethane adhesive (trade name; LX901 / KW75:
A laminated packaging material of the present invention was produced by repeating Example 3 except that aluminum foil having a thickness of 9 μm was laminated using (manufactured by Dainippon Ink and Chemicals, Inc.).

When the obtained packaging material is torn by hand, at the end of tearing, the deviation from the linear direction can be suppressed within 0 to 3 mm on the front side of the tearing, and also on the back side to 0 to 5 mm. And showed excellent tearability (straight cut property). Moreover, since the laminated packaging material of this example further had the polyethylene terephthalate layer, the overall rigidity was improved, and its standing property was improved. In addition, since it has a layer of aluminum foil, it was excellent in oxygen and water vapor barrier properties.

[0034]

According to the present invention, a laminated packaging material suitable for a flat bag or a standing pouch using a nylon film having excellent impact resistance is further provided with a stretched polyethylene layer having a good linear cut property and an unsealing auxiliary member. Even without the provision, it was possible to impart the property of tearing linearly with the hand.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminated packaging material of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the laminated packaging material of the present invention.

FIG. 3 is a cross-sectional view of still another embodiment of the laminated packaging material of the present invention.

[Explanation of symbols]

 1 Nylon film 2 Heat sealable resin layer 3 Outer layer 4 Gas barrier layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location B65D 65/40 A 9028-3E // B29L 9:00 4F (72) Inventor Junichi Uchida Taito, Tokyo 1-5-1, Taito-ku, Tokyo, Toppan Printing Co., Ltd.

Claims (6)

[Claims] 1. A laminated packaging material in which a nylon film and a heat-sealable resin layer are sequentially laminated, wherein the nylon film is a biaxially stretched film composed of aromatic polyamide and 6-nylon. Packaging material. 2. The laminated packaging material according to claim 1, wherein an outer layer is laminated on the surface of the nylon film opposite to the heat-sealing resin layer. 3. The outer layer is a polyethylene terephthalate film or a biaxially oriented polypropylene film, and the heat-sealable resin layer is a low density polyethylene.
The laminated packaging material described. 4. The laminated packaging material according to claim 2, wherein a gas barrier layer is provided between the nylon film and the outer layer or the heat-sealable resin layer. 5. The laminated packaging material according to claim 4, wherein the gas barrier layer is an aluminum foil, a polyvinylidene chloride layer or a silicon oxide vapor deposition layer. 6. The laminated packaging material according to claim 1, wherein at least one of the layers is adhered with a urethane adhesive.