JP2011031439A - Two-layer packing film with perforation, and packing bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a two-layer packing film with perforation which is excellent in transparency and a gas barrier property, has a good opening nature and can be manufactured inexpensively. <P>SOLUTION: A synthetic resin film forms an outer layer of a packing bag and is constituted of a base material synthetic resin film layer, in which an ink layer for printing is formed on its inside surface and the perforation penetrating the film surface is formed in advance, a thermally sealable synthetic resin film layer, which is formed of the synthetic resin film forming an inner layer of the packing bag, and a gas barrier adhesive layer, which joins the base material synthetic resin film layer and the thermally sealable synthetic resin film layer. The gas barrier adhesive layer is formed by using a heat resistant resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a packaging film having a multilayer structure having gas barrier properties, and more particularly to a two-layer film for perforated packaging having a perforation for opening and a packaging bag using the same.

  Conventionally, a packaging film that can be opened smoothly and surely with a break such as a perforation provided in one layer of a laminated film with respect to contents that need to block water vapor and oxygen, It consists of a multilayer film consisting of “film layer” (base material layer), “water vapor / oxygen barrier film layer” (gas barrier layer), and “heat sealable film layer” (thermal welding layer). Are laminated with an adhesive layer to form a laminated laminate film.

  Specifically, as shown in FIG. 4 (a), a film layer 10 / design layer etc. for printing perforations from the outside to the inside when configured as a packaging bag / an adhesive layer 11 / an adhesive layer 12 / film layer 13 having water vapor / oxygen barrier property / adhesive layer 14 / film layer 15 capable of heat sealing. At least three types of film layers 10, 13, 15 are formed into adhesive layers 12, 14 It was the structure joined by.

  Alternatively, as shown in FIG. 4B, from the outside to the inside when configured as a packaging bag, the film 13 / ink layer 11 / adhesive layer 12 / perforation having water vapor / oxygen barrier properties is formed. It is composed of a film layer 10 to be inserted / an adhesive layer 14 / a film layer 15 capable of heat sealing. In the same manner as described above, at least three types of film layers 10, 13, 15 are joined by adhesive layers 12, 14. there were.

  In addition, a laminated film composed of a gas barrier film, a base film having a perforation, and a heat-welded film is formed by bonding each layer with an adhesive layer. However, in order to ensure reliable gas barrier properties, The thing provided with the vapor deposition thin film layer by a metal oxide between a layer and a base material layer is proposed (patent document 1).

JP-A-11-58590

  By the way, the conventional packaging film having the three-layer structure requires two adhesive layers 12 and 14 in addition to the gas barrier film 4 having water vapor / oxygen barrier properties, and therefore the cost is high and the manufacturing is performed at a lower cost. A packaging film having a high gas barrier property is desired.

  Moreover, in the packaging film of the said patent document 1, the metal oxide vapor deposition thin film layer is used, There exists a subject that it is expensive as packaging films, such as a foodstuff.

  The present invention has been made in view of the above-described conventional problems, and has an object to provide a two-layer film for perforated packaging and a packaging bag that are excellent in unsealing properties, have high gas barrier properties, and are easy to manufacture at low cost. To do.

In order to achieve the above object, the present invention
1stly, it is a synthetic resin film which forms the outer layer of a packaging bag, Comprising: While the ink layer for printing is formed in an inner surface, the base synthetic resin film in which the perforation which penetrates the said film surface previously was formed A synthetic resin film that forms a layer and an inner layer of the packaging bag, the gas barrier joining the heat-sealable synthetic resin film layer, the base-material synthetic resin film layer, and the heat-sealable synthetic resin film layer The gas barrier adhesive layer is composed of a two-layer film for perforated packaging, which uses a heat-resistant resin.

  If comprised in this way, gas barrier property is high by the dry laminating method using a barrier adhesive, or the extrusion laminating method using a barrier adhesive as an anchor coating agent, and even if it heat-processes, opening property will not be impaired. A two-layer film for perforated packaging can be realized at low cost.

  Second, the base material synthetic resin film layer, the heat-sealable synthetic resin film layer, and the gas barrier adhesive layer are all made of a transparent resin, It is composed of a two-layer film for packaging.

  If comprised in this way, it will become possible to manufacture the transparent two-layer film for packaging with high gas barrier property at low cost.

  Thirdly, a sewing bag formed on the base synthetic resin film layer is formed by thermally welding the periphery of two heat-sealable synthetic resin film surfaces of the two perforated packaging double-layer films to form a packaging bag. It is comprised by the packaging bag by the 2 layer film for perforated packaging as described in the said 1st or 2 formed by forming the cut for opening by eyes.

  If comprised in this way, the packaging bag which has high gas barrier property and does not impair opening property even if it heat-processes can be implement | achieved at low cost.

  Since the present invention is configured as described above, by using a gas barrier adhesive, two layers for perforated packaging with high gas barrier properties without using a vapor-deposited film, and the openability is not impaired even if heat treatment is performed. A film can be realized at low cost.

  In addition, a highly transparent two-layer film for perforated packaging can be realized at low cost while maintaining gas barrier performance.

  In addition, it is possible to realize a packaging bag that has high gas barrier properties and does not impair the openability even when heat treatment is performed.

It is sectional drawing which shows the 2 layer film for perforated packaging which concerns on this invention. It is a front view of the said 2 layer film which shows the condition which forms a packaging bag from a 2 layer film same as the above. It is sectional drawing of the packaging material formed with the two-layer film same as the above. (A) (b) is sectional drawing of the conventional water vapor | steam and oxygen barrier multilayer film.

  Hereinafter, the perforated double-layer film for packaging and the packaging bag of the present invention will be described in detail.

(Structure of multilayer packaging film)
As shown in FIG. 1, a base synthetic resin film layer 1 to be perforated and a heat-weldable synthetic resin film layer (synthetic resin film layer) 2 capable of heat sealing are combined with a barrier adhesive layer (gas barrier adhesive layer). ) Joined at 3 to form a two-layer film 4 for packaging food or the like.

  The base synthetic resin film layer 1, the heat-welding synthetic resin film layer 2 and the barrier adhesive layer 3 are each transparent and printed with characters, photographs, etc. on the inner surface side of the base synthetic resin film layer 1 By forming the ink layer 5 by applying the above, the characters and the like can be seen through from the surface side of the base synthetic resin film layer 1.

  Since the film layers 1 and 2 and the adhesive layer 3 are transparent, the contents can be seen through from the outside if the ink layer 5 is not present. Alternatively, even if the ink layer 5 is present, the contents can be seen through from the outside in a portion where the ink layer 5 is not present.

(Base synthetic resin film layer 1)
The base synthetic resin film layer 1 is provided with a perforation 6 in a penetrating state and imparts mechanical strength to the film. Therefore, a material having mechanical strength, such as a biaxially oriented polypropylene film (OPP), A biaxially stretched film such as a biaxially stretched polyester film or a stretched nylon film is used. In either case, a transparent film is used.

(Heat weldable synthetic resin film layer 2)
The heat-weldable synthetic resin film layer 2 is preferably a low melting point polymer layer that melts at a low temperature. For example, an unstretched polypropylene film (CPP) or a low-density polyethylene unstretched film is used. The heat-weldable synthetic resin film layer 2 is also a transparent film.

(Barrier adhesive layer 3)
Examples of the barrier adhesive layer 3 include a two-component curable polyurethane resin composition composed of a component mainly composed of an active hydrogen-containing compound and a component mainly composed of an organic polyisocyanate compound. As a known product (for example, JP-A-2005-161690), “MAXIVE” (registered trademark), which is an adhesive for gas barrier dry laminate manufactured by Mitsubishi Gas Chemical Industries, Ltd., can be used. This barrier adhesive is preferably colorless and transparent.

  The barrier adhesive used in the present invention uses a heat-resistant resin, for example, a two-component curable polyurethane resin composition. When contents that require heat treatment such as boil sterilization and retort sterilization are added, heat treatment at 120 ° C. or lower is required. Therefore, by using a heat-resistant barrier adhesive, the water vapor / oxygen barrier function does not deteriorate even when the above heat treatment is performed, and a packaging film that does not deteriorate easy-openability due to perforation is possible. It becomes.

(Ink layer 5)
The ink layer is provided in advance on the back surface side (inner surface side of the packaging bag) of the base synthetic resin film 1, and is printed with a trade name, a photograph of the contents, a description, and the like.

(Perforation 6)
The perforation (opening cut) 6 is formed through the base synthetic resin film layer 1. Various shapes can be considered for the perforation 6. For example, as shown in FIG. 2, the shape of the perforation 6 is “C” as shown in FIG. 2 in a direction perpendicular to the longitudinal direction of the base synthetic resin film layer 1. Is previously formed.

(Manufacturing method of packaging two-layer film 4)
The packaging two-layer film 4 according to the present invention can be produced by any conventionally known dry laminating method or extrusion laminating method.

  First, the base synthetic resin film is printed on the inner surface side (one surface side) with a multicolor gravure printing machine while drawing the film from the roll of the film to form the ink layer 5, for example, the final gravure printing machine In the printing unit, a perforated blade of “C” is provided on the roller in a direction orthogonal to the film traveling direction, and by rotating the roller, the perforated blade causes the “ha” at regular intervals of the film. The U-shaped perforation 6 is formed to penetrate (FIG. 2) and wound up again.

  In the case of the dry laminating method, the barrier adhesive is applied while pulling out the heat-welding synthetic resin film, and after drying to form the barrier adhesive layer 3, the surface on which the barrier adhesive is applied is applied. The two-layer film 4 for perforated packaging can be manufactured by laminating the surfaces of the substrate synthetic resin film on which the ink layer 5 is formed.

  In the case of the extrusion laminating method, the barrier adhesive is used as an AC agent (anchor coat agent). The barrier adhesive is applied as an AC agent to the surface on which the ink layer 5 is formed while the base synthetic resin film on which the perforations 6 and the ink layer 5 are formed is pulled out from the roll. Then, after the AC agent is dried to form the barrier adhesive layer 3, the heat weldable synthetic resin is extruded from the extruder onto the AC agent-coated surface to form the heat weldable synthetic resin film layer 2, A two-layer film 4 for perforated packaging can be produced.

(Manufacture of packaging bags)
In order to manufacture a packaging bag using the perforated packaging two-layer film 4, the two-layer film 4 is pulled out from each of the two rolls of the packaging two-layer film 4, and the heat of each of the two films 4 is heated. The surfaces of the weldable synthetic resin film layer 2 are opposed to each other (FIGS. 2 and 3), and the heat weldable synthetic resin film layers 2 and 2 are opposed to each other by heating the side portions 7a and 7b and the linear portion 7c orthogonal to the longitudinal direction. The packaging bag 8 can be formed by heat-sealing and cutting it in units (a and a ′ positions in FIG. 2). Thereafter, the contents are put into the packaging bag 8 and the opening is sealed.

  When the packaging bag 8 is opened, it can be easily opened by tearing the film along the eight-shaped perforation 6 in the width direction line from the side portion 7a of the packaging bag 8.

  As described above, according to the present invention, the perforation 6 and the base layer synthetic resin film on which the ink layer 5 is formed are bonded to the base synthetic resin film by using a barrier adhesive to bond the sewing machine. Since the two-layer film 4 for weight packaging is constructed, it is not necessary to use a special film for gas barrier having water vapor / oxygen barrier properties (for example, K nylon, MXD nylon, KOP (registered trademark), etc.). -A two-layer film having oxygen barrier properties and good linear cut properties can be produced at low cost.

  Further, by using a heat-resistant resin as the gas barrier adhesive layer 3, for example, for contents that require heat treatment (120 ° C. or less) such as boil sterilization and retort sterilization after the contents are stored and sealed. It can also be used as a packaging material. That is, since the adhesive 3 does not penetrate into the perforation 6 even after heat treatment, the easy cut property of the perforation 6 is not impaired even after the heat treatment, and the gas barrier property of water vapor and oxygen is maintained. It is possible to realize a two-layer film for packaging.

  As a base synthetic resin film, a biaxially stretched polypropylene film, as a barrier adhesive, a two-component curable polyurethane resin composition, as a heat-weldable synthetic resin film, an unstretched linear low-density polyethylene film is used, After printing on the base synthetic resin film with a gravure printing machine, a perforation 6 having a letter “C” was formed. Thereafter, the two-layer film 4 for perforated packaging is bonded to the surface of the base synthetic resin film on which the ink layer 5 is formed using a barrier adhesive by a dry laminating method. Formed.

And the two sides of the two-layer film 4 for packaging and the three sides of the straight portions 7a, 7b and 7c are sealed by thermal welding to form a packaging bag 8, and the remaining one side is stored with the contents. The contents were sealed by heat welding, and sterilization heat treatment at 90 ° C. was performed. Thereafter, when the barrier property was tested, it was possible to provide a barrier property of 70.0 ml / m ² · day · MPa or less.

  Therefore, the packaging bag 8 using the two-layer film 4 for perforated packaging according to the present invention is made of a gas barrier layer made of a barrier synthetic resin film having water vapor and oxygen barrier properties such as K nylon, MDX nylon, KOP (registered trademark). It was confirmed that the film had the same barrier property as that used in the above case, and that despite having the perforation 6 penetrating the base synthetic resin film layer 1, it was possible to exhibit good barrier performance.

  Therefore, even if K nylon, MDX nylon, KOP (registered trademark) is used as the base synthetic resin film layer 1 and the perforation 6 is formed through these films, the barrier adhesive 3 is used. It was found that further water vapor / oxygen barrier property (barrier property) can be secured by using the two-layer film 4 for perforated packaging of the present invention in the same manner as above.

  As described above, the present invention uses a gas barrier adhesive, and does not use a barrier film such as a vapor-deposited film. Therefore, the gas barrier property is high, and the perforated packaging does not impair the openability even if heat treatment is performed. A two-layer film can be produced at low cost.

  In addition, since the two-layer film for perforated packaging with high transparency can be produced at low cost while maintaining the gas barrier performance, it is very effective as a food packaging bag or the like.

  In addition, since the gas barrier property is high and the openability is not impaired even if heat treatment is performed, the film is extremely effective as a packaging film for containing contents necessary for boil sterilization and retort sterilization.

  The two-layer film for perforated packaging of the present invention is not limited to the food field, and can be widely used as a packaging film for contents requiring gas barrier properties such as chemicals, chemicals, and cosmetics.

1 base material synthetic resin film layer 2 heat welding synthetic resin film layer (synthetic resin film layer)
3 Gas barrier adhesive layer (barrier adhesive layer)
4 Double-layer film for packaging (double-layer film for perforated packaging)
5 Ink layer 6 Perforation 8 Packaging bag

Claims (3)

A synthetic resin film that forms an outer layer of a packaging bag, and a base synthetic resin film layer in which an ink layer for printing is formed on an inner surface and a perforation that penetrates the film surface is formed in advance,
A synthetic resin film that forms the inner layer of the packaging bag, and a heat-sealable synthetic resin film layer;
A gas barrier adhesive layer that joins the base synthetic resin film layer and the heat-sealable synthetic resin film layer;
2. The two-layer film for perforated packaging, wherein the gas barrier adhesive layer uses a heat-resistant resin.   2. The two-layer perforated packaging according to claim 1, wherein the base synthetic resin film layer, the heat-sealable synthetic resin film layer, and the gas barrier adhesive layer are all made of a transparent resin. the film. Heat-sealing around the heat-sealable synthetic resin film surfaces of the two perforated packaging two-layer films to form a packaging bag,
The packaging bag by the 2-layer film for perforated packaging of Claim 1 or 2 formed by forming the opening cut | interruption with the perforation formed in the said base material synthetic resin film layer.

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