JP2006326998A - Laminated film and packaging bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated film which can improve linear tear even when a laminate is simple without passing through an extra process, such as perforations, and provide a packaging bag obtained by the laminated film. <P>SOLUTION: A first layer by a transparent inorganic acid oxide, a first adhesive layer by a first adhesive, a first polymer resin film layer by a first polymer resin film, a second adhesive layer by a second adhesive, and a second polymer resin film layer by a second polymer resin film are laminated in turn on the surface of a substrate plastic film to be a substrate to form the laminated film. Each of the substrate plastic film and the first polymer resin film layer is superior in so-called linear tear properties. When the laminated film is formed, the substrate plastic film and the first polymer resin film layer are laminated so that they are superior in tearing properties in the same direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminated film and a packaging bag using the laminated film, and more specifically, a laminated film excellent in linear tearability, and a packaging for storing foods using the laminated film. Regarding bags.

  In recent years, with the change of lifestyle, so-called retort food has been widely distributed. And the contents are variously various so far.

  A laminated film as a raw material for a packaging bag used for such a purpose is strongly required to have a property of suppressing / preventing deterioration of contents, that is, a gas barrier property. In particular, recent retort foods contain a variety of foods and ingredients as described above, but they are easily altered by oxygen and water vapor. What is needed is a packaging material with gas barrier properties that makes it easy to protect things.

  However, as a packaging bag for retort foods, maintaining the gas barrier property at a high level and at the same time, how easily the bag can be opened quickly has emerged as an important issue equivalent to the gas barrier property. .

  In conventional retort food packaging bags, the laminated film, which is the raw material for pursuing gas barrier properties, was not easily torn. However, it was not easy, and for example, if opening was attempted with force, the bag would tear and the contents would scatter easily.

  For this reason, various laminated films, which are packaging materials that can be easily opened by tearing by hand when used as a retort food packaging bag, have been proposed.

  For example, in the invention described in Patent Document 1, a laminated film for packaging material having a configuration of gas barrier synthetic resin film / synthetic resin film layer / perforated resin film layer provided with perforations is described.

Japanese Patent Laid-Open No. 11-58590

  In the case of the film described in Patent Document 1, it is possible to tear along the perforation when the film is torn, so that easy opening can be secured, and the perforation is further improved. If it is on a straight line, it is easy to improve the straight tearing property. However, when attention is paid to the fact that the laminated film described in Patent Document 1 is actually manufactured, the film used for the intermediate layer is bothered. It is necessary to provide eyes, and the work is troublesome, and the process of providing perforations becomes an extra problem. Furthermore, in view of the manufacturing cost for carrying out this process, an extra cost is required, which is not preferable. Furthermore, in order to obtain easy straight tearing, the perforation must be provided in a straight line and must be handled carefully with respect to the direction of the perforation at the time of lamination, and it is never easy to handle. It was hard to say that there was.

  The present invention has been made in view of such problems, and its object is to improve linear tearing even in a simple and simple laminate without going through an extra step such as providing a perforation. It is providing the laminated | multilayer film which can be manufactured, and the packaging bag obtained by this laminated | multilayer film.

  In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention includes a first layer made of a transparent inorganic oxide and a first adhesive layer made of a first adhesive on the surface of a base plastic film serving as a base material. And a first polymer resin film layer made of the first polymer resin film, a second adhesive layer made of the second adhesive, and a second polymer resin film layer made of the second polymer resin film in this order. The base plastic film and the first polymer resin film layer are both excellent in linear tearing properties, and when the base film is formed, A product obtained by laminating the base plastic film and the first polymer resin film so that the plastic film and the first polymer resin film layer have excellent tearability in the same direction. It is a film, characterized by.

  The invention according to claim 2 of the present invention is characterized in that a first adhesive layer made of a first adhesive, a first layer made of a transparent inorganic oxide, and a first polymer resin are formed on the surface of a base plastic film serving as a base material. A laminated film in which a first polymer resin film layer made of a film, a second adhesive layer made of a second adhesive, and a second polymer resin film layer made of a second polymer resin film are laminated in this order. The base plastic film and the first polymer resin film layer are both excellent in linear tearing properties, and when the laminated film is formed, the base plastic film and the first high resin film layer are formed. The molecular resin film layer is a laminated film formed by laminating the base plastic film and the first polymer resin film so that the tearability is excellent in the same direction. And butterflies.

  The invention according to claim 3 of the present invention is the laminated film according to claim 1 or claim 2, wherein the base plastic film is a laminated film that is a polyethylene terephthalate film having excellent linear tearing properties. It is characterized by.

  According to a fourth aspect of the present invention, in the laminated film according to any one of the first to third aspects, the first polymer resin film is a polyamide film excellent in linear tearability. It is a laminated film.

  The invention according to claim 5 of the present invention is characterized in that, in the laminated film according to claim 4, the polyamide film is a simultaneously biaxially stretched polyamide film produced by a tubular method.

  The invention according to claim 6 of the present invention is the laminated film according to any one of claims 1 to 5, wherein the transparent inorganic oxide is one of silicon oxide and aluminum oxide, It is the laminated film which is plural, It is characterized by the above-mentioned.

  The invention according to claim 7 of the present invention is the laminated film according to any one of claims 1 to 6, wherein the second polymer resin film is an unstretched polypropylene film. It is characterized by this.

  The invention according to claim 8 of the present invention is the laminated film according to any one of claims 1 to 7, wherein the first adhesive or the second adhesive is a polyester resin or a polyether resin. It is a laminated film which is one or a plurality of resins and polyurethane resins.

  The invention according to claim 9 of the present invention is a packaging bag obtained by using the laminated film according to claims 1 to 8.

  As described above, compared with the so-called easily tearable laminated film and the easily tearable packaging material, which has been conventionally handled by, for example, perforation in advance, the laminated film according to the present invention can be used as a laminated film. By laminating the base film and the first polymer resin film in the same direction of easy tearing, the resulting laminated film will also exhibit easy tearing properties in the same direction. Is a linear tearing property, the resulting laminated film can be made to be easily tearable linearly.

  And if it is set as a packaging bag using such a straight-line tearable film, even if this is used, for example, for retort food packaging, there is no situation where the contents are scattered when it is difficult to tear when opened. When opened, it can be easily torn linearly in a desired direction, so that it can be a very suitable product.

  Embodiments of the present invention will be described below. The embodiment shown here is merely an example, and is not necessarily limited to this embodiment.

(Embodiment 1)
The laminated film according to the present invention will be described as a first embodiment.
The laminated film according to the present embodiment includes a first layer made of a transparent inorganic oxide, a first adhesive layer made of a first adhesive, and a first polymer resin film on the surface of a base plastic film serving as a base material. The first polymer resin film layer, the second adhesive layer made of the second adhesive, and the second polymer resin film layer made of the second polymer resin film are laminated in this order.

  The base plastic film and the first polymer resin film layer are both excellent in so-called linear tearing properties, and when formed into a laminated film, the base plastic film and the first polymer resin film layer Are laminated so that tearability is excellent in the same direction.

  The order of lamination of the first layer made of the transparent inorganic oxide and the first adhesive layer made of the first adhesive may be reversed, but in this embodiment, the surface of the base plastic film The first layer is laminated, and then the first adhesive layer is laminated on the surface.

  First of all, it is a base plastic film as a base material, but this sheet needs to have good linear tearability from the beginning. The specific sheet is not particularly limited as long as it has linear tearability, but in the present embodiment, it is a polyethylene terephthalate (PET) film suitable for use as a base material for a vapor deposition film. And The PET film needs to have good linear tearability, and the reason will be described later. The thickness of the PET film is preferably 5 μm or more and 25 μm or less in consideration of the thickness of the entire laminated film to be obtained and required flexibility, but in this embodiment, it is 12 μm. .

  If a PET film excellent in linear tearability is prepared as the base plastic film, a first layer made of a transparent inorganic oxide is then laminated on the surface. As this transparent inorganic oxide, for example, silicon oxide, aluminum oxide, or the like is conceivable, and these are preferable because gas barrier properties can be obtained, but in this embodiment, silicon oxide is used. . It is preferable to use these as the first layer made of a transparent inorganic oxide. When these are laminated, gas barrier properties are imparted to the laminated film, and the resulting layer is substantially transparent, that is, visibility. This is because it can be a good product.

  If it has gas barrier properties and good visibility, it can be used as a packaging material to always protect the contents from oxygen, water vapor, etc. This is because the packaging material can be easily recognized from the viewpoint of easy management and storage. The thickness of the first layer is preferably 100 mm or more and 1000 mm or less in consideration of the thickness of the entire laminated film to be obtained, required flexibility, and the like, but in this embodiment, it is 400 mm. The method for laminating the first layer may be a conventionally known method. For example, the lamination may be performed by a method such as a vacuum deposition method or a sputtering method. In this embodiment, it is assumed that the vacuum evaporation method is used.

If a 1st layer is laminated | stacked, the 1st contact bonding layer by a 1st adhesive agent will be provided in the surface next.
The first adhesive is preferably any one or more of a polyester resin, a polyether resin, and a polyurethane resin. In the present embodiment, the first adhesive is a polyester resin. And the thickness of the 1st contact bonding layer obtained should just be 2 micrometers or more and 5 micrometers or less, but it shall be 3 micrometers here. As described repeatedly, these thicknesses may be determined in consideration of the thickness of the entire laminated film to be obtained and its flexibility.

  Moreover, although the formation method of a 1st contact bonding layer may be a conventionally well-known thing, it shall be the gravure coating method in this Embodiment.

  Next, when a 1st contact bonding layer is formed, the 1st polymer resin film layer by a 1st polymer resin film is formed in the surface. Specifically, the first polymer resin film is not particularly limited as long as it is a plastic film excellent in linear tearability, but in the present embodiment, it is a polyamide film excellent in linear tearability. It is even more preferable if this is a simultaneous biaxially stretched polyamide film produced by a tubular method. If a polyamide film is used, it is still preferable because it is excellent in pinhole resistance and toughness. The thickness is preferably 5 μm or more and 25 μm or less in consideration of the thickness of the entire laminated film to be obtained, required flexibility, and the like, but in the present embodiment, it is 15 μm. And this 1st polymer resin film layer is laminated | stacked by the dry lamination method using presence of a 1st adhesive agent, By this, a base plastic film and a 1st polymer resin film are bonded together is there.

  Here, the relationship between the base plastic film and the first polymer resin film layer will be described.

  As already mentioned, it is important that the films used for these two layers are both excellent in linear tearing properties, but in advance, they are excellent in linear tearing properties. When a laminated body using a film having excellent properties is formed, the obtained laminated body is attracted by the linear tearability of the film having linear tearability, and as a whole, it becomes excellent in linear tearability. The purpose of the laminated film according to the present embodiment is to have excellent linear tearability, and for this purpose, the film constituting the laminated film according to the present embodiment has excellent linear tearability. That is important.

  In addition to this, in the present embodiment, it is important to align the directions of the linear tearability of these two layers.

  In more detail, the purpose of the laminated film according to the present invention is to make the product excellent in linear tearability, but when the two films have different tear directions, the resulting laminated film Even if the tearing direction is different, if the tearing directions are different from each other, the tearing directions cancel each other, resulting in a laminated film similar to the conventional film that does not easily tear.

  However, by aligning these easy tearing directions, it becomes possible to easily tear in a straight line in the same direction even if the entire laminated film obtained is considered. Therefore, when these two films are laminated, it is necessary to make the direction in which they are easy to tear the same direction.

  That is, for example, in the case of laminating three films, when only one sheet has excellent linear tearability and when two sheets have excellent linear tearability, there is only one sheet. Compared to the case, the case of two sheets can be further improved in linear tearing property due to the synergistic effect.

  However, in the case of these three sheets, if all the three sheets are excellent in linear tearability in the same direction, this time, it will be more excellent in tearability than necessary, for example, even when not necessary It will be torn and will not be practical.

  Therefore, in the case of the present embodiment, three films are used, but only two of them are excellent in linear tearability, and when these are laminated, the film is excellent in linear tearability in the same direction. It is said that.

  When the first polymer resin film layer is provided in this way, the second adhesive layer made of the second adhesive is laminated on the surface. Here, the second adhesive is the same as the first adhesive described above. You may choose from the thing quoted as a 1st adhesive agent. In any case, since the second adhesive is the same as the first adhesive, further detailed description is omitted here.

  If the 2nd adhesive layer by a 2nd adhesive agent is laminated | stacked, the 2nd polymer resin film layer by a 2nd polymer resin film will be laminated | stacked on the surface finally.

  The second polymer resin film used here may be a polymer resin film such as an unstretched polypropylene (CPP) film or a linear low-density polyethylene (LLDPE) film. In this embodiment, the heat seal material is used. As a general CPP film.

  The thickness is preferably 40 μm or more and 100 μm or less in consideration of the thickness of the entire laminated film to be obtained and the required flexibility, as in the case of the other layers, but in this embodiment, it is 60 μm. Suppose that The method of laminating the second polymer resin film layer may be a conventionally known method. For example, the first polymer resin film and the second polymer resin film using the second adhesive are dry laminated. Lamination may be performed by sticking.

  The laminated film according to the present embodiment obtained as described above can be easily teared in a predetermined linear direction when necessary. And if the straight line direction is determined and this is used as a packaging bag, the resulting packaging bag can be easily torn in a certain straight line direction. For example, this is a retort food packaging bag. Then, a packaging bag having gas barrier properties and excellent visibility can be easily opened in a certain linear direction.

  In addition, although it is the relationship between the 1st layer and the 1st contact bonding layer which was described first in this Embodiment, it can fully be set as the structure which reversed these, In that case, base-material plastics After the first adhesive layer is laminated on the surface of the film, the first layer may be laminated on the surface, and further details are the same as those already described, and further explanation is omitted.

Claims (9)

On the surface of the base plastic film that becomes the base,
A first layer of a transparent inorganic oxide;
A first adhesive layer with a first adhesive;
A first polymer resin film layer comprising a first polymer resin film;
A second adhesive layer with a second adhesive;
A second polymer resin film layer made of a second polymer resin film;
Are laminated films formed by laminating in this order,
The base plastic film and the first polymer resin film layer are both excellent in linear tearing properties,
And when it becomes the said laminated | multilayer film, the said base plastic film and said 1st polymer resin film are made so that the said base plastic film and said 1st polymer resin film layer may be excellent in tearability in the same direction. Layered,
A laminated film characterized by On the surface of the base plastic film that becomes the base,
A first adhesive layer with a first adhesive;
A first layer of a transparent inorganic oxide;
A first polymer resin film layer comprising a first polymer resin film;
A second adhesive layer with a second adhesive;
A second polymer resin film layer made of a second polymer resin film;
Are laminated films formed by laminating in this order,
The base plastic film and the first polymer resin film layer are both excellent in linear tearing properties,
And when it becomes the said laminated | multilayer film, the said base plastic film and said 1st polymer resin film are made so that the said base plastic film and said 1st polymer resin film layer may be excellent in tearability in the same direction. Layered,
A laminated film characterized by In the laminated film according to claim 1 or 2,
The base plastic film is a polyethylene terephthalate film excellent in linear tearability;
A laminated film characterized by In the laminated film according to any one of claims 1 to 3,
The first polymer resin film is a polyamide film excellent in linear tearability;
A laminated film characterized by In the laminated film according to claim 4,
The polyamide film is a simultaneously biaxially stretched polyamide film produced by a tubular method;
A laminated film characterized by In the laminated film according to any one of claims 1 to 5,
The transparent inorganic oxide is any one or more of silicon oxide and aluminum oxide,
A laminated film characterized by In the laminated film according to any one of claims 1 to 6,
The second polymer resin film is an unstretched polypropylene film;
A laminated film characterized by In the laminated film according to any one of claims 1 to 7,
The first adhesive or the second adhesive is any one or more of a polyester resin, a polyether resin, or a polyurethane resin,
A laminated film characterized by Obtained using the laminated film according to claim 1 to claim 8,
A packaging bag.