JP2014005070A - Laminated film for easy-to-open barrier packaging bag, method of manufacturing the same, and barrier packaging bag using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film for an easy-to-open barrier packaging bag which prevents perforations from appearing on surfaces.SOLUTION: A laminated film 1 comprises aluminum foil 2 the two surfaces of which consist of a low-gloss rough surface 2a and a glossy surface 2b. On the rough surface 2a of the aluminum foil 2, a biaxially stretched polyamide film 7 and a sealing layer 8 are laminated in sequence. A biaxially stretched polyester film or polyester/polyamide multilayer film 9 is laminated on the glossy surface 2b of the aluminum foil 2. Perforations 10 are formed in the biaxially stretched polyamide film 7.

Description

  The present invention generally relates to a laminate film for an easy-open barrier packaging bag, and more particularly relates to an improved laminate film for an easy-open barrier packaging bag and a method for producing the same. The present invention relates to a barrier packaging bag made using such a laminate film.

  The packaging bag is required to have various important performances such as impact resistance, environmental stress cracking resistance, seal stability, and fragrance retention, and must have excellent storage stability. The applicant has proposed a laminate film shown in the cross-sectional view of FIG. 4 (A), which is used for an easily openable barrier packaging bag that satisfies such properties and facilitates easy opening (patents). Reference 1).

  Referring to FIG. 4A, a conventional laminate film 1 includes an aluminum foil 2 that is a barrier film. A PET film 4 is laminated on one surface of the aluminum foil 2 with a low density polyethylene (LDPE) film 3 as an adhesive layer interposed therebetween. The perforation 5 is put in the PET film 4 by a perforation blade. On the other surface of the aluminum foil 2, a low density polyethylene (LDPE) film 6 which is a polyolefin film serving as a seal layer is laminated.

  Referring to FIG. 4B, two laminate films 1 are laminated with the low-density polyethylene (LDPE) film 6 serving as a seal layer inside, and the seal layer is heat sealed. Thereby, the easy-openability barrier packaging bag from which preferable transportability and easy-openability are obtained is provided.

  FIG. 4C is a front view of the obtained easily openable barrier packaging bag. FIG. 4B is a cross-sectional view taken along line BB in FIG. There is also a method using a carbon dioxide laser as a method of perforating (Patent Document 2).

JP 2008-201422 A JP-A-10-17013

  However, the technique disclosed in Patent Document 1 has a problem that perforations appear on the surface as shown in FIG. The technique disclosed in Patent Document 2 has the same problem.

  By the way, the aluminum foil used as the barrier film has a glossy surface and a satin surface. The reason why such different surfaces can be made on the front and back is as follows. That is, the aluminum foil is manufactured by a method called rolling. Rolling is a method in which a thin aluminum plate is sandwiched between two rolls to be crushed and thinned. In practice, two larger rolls are arranged and a total of four rolls are used. However, with this method, no matter how much load is applied, the thickness of the foil that can be achieved is limited to 10 μm. In order to make a thinner aluminum foil, "superposition rolling" is performed. On the roll entry side, two sheets of material are stacked and bitten by the roll, and on the exit side, they are wound around one coil. Then, a foil having a thickness of 5 μm can be made (minimum thickness 10 μm ÷ 2 sheets = 5 μm). The foil wound on one coil on the exit side is separated in the next separation step and separated one by one. The surface that is rolled in direct contact with the rolling roll is in a glossy specular state as a result of the material structure being forced to collapse in one direction by the roll. On the other hand, the back surface where the foils are brought into contact with each other is rolled, and as a result of the material structure being crushed in a random direction, light is irregularly reflected to give a matte texture.

  The inventor has found that when the carbonic acid laser light is irradiated toward each of the glossy surface and the pear ground, the inventors have shown different behaviors and have reached the present invention.

  An object of the present invention is to provide a laminate film for an easily openable barrier packaging bag which is improved so that perforations do not appear on the outside.

  Another object of the present invention is to provide a method for producing such a laminate film for an easily openable barrier packaging bag.

  Another object of the present invention is to provide a barrier packaging bag produced using such a laminate film for an easily openable barrier packaging bag.

  A laminate film for an easy-open packaging bag according to the present invention includes an aluminum foil having a low gloss surface and a glossy surface on the front and back, a biaxially stretched polyamide film and a seal laminated sequentially on the surface of the aluminum foil. And a biaxially stretched polyester film or a polyester / polyamide laminated film laminated on the glossy surface of the aluminum foil. The biaxially stretched polyamide film has perforations.

  The sealing layer may be any material that can be melted by heat and fused to each other. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene- Vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, acid-modified ethylene-acrylic A stretched film made of a polyolefin resin such as an acid copolymer or an ethylene-methacrylic acid copolymer, an unstretched film, or a film formed by an extrusion lamination method can be used. In the present invention, an unstretched polypropylene film is particularly preferably used.

  The biaxially stretched polyamide film has an orientation close to the flow direction of the film, the tearing deviation is very small even when they are overlapped, and the absorption wavelength of the carbon dioxide gas laser is absorbed. It has an advantage that laser processing can be easily performed. Examples of the biaxially stretched polyamide film include nylon films such as nylon-6, nylon-66, nylon-11, nylon-12, nylon-6,10.

  Since the film laminated on the glossy surface of the aluminum foil is required to be a resin film having rigidity to be used as an outer layer and excellent in strength, in the present invention, as the resin film, Since it becomes a basic material constituting the packaging bag, a biaxially stretched polyester film or a polyester / polyamide laminated film having excellent properties in mechanical, physical, chemical, etc. is used.

  The method according to another aspect of the present invention includes a low-gloss pear surface, an aluminum foil having glossy surfaces on the front and back, a biaxially stretched polyamide film and a seal layer sequentially laminated on the pear surface of the aluminum foil, Preparing a laminated film having a biaxially stretched polyester film or a polyester / polyamide laminated film laminated on the glossy surface of the aluminum foil, and passing through the sealing layer from the side on which the sealing layer is formed. Irradiating a carbon dioxide laser toward the surface of the foil and engraving a perforation in the biaxially stretched polyamide film.

  The method for producing the laminate film to be prepared will be described. Such a method includes a method of laminating a normal packaging material, for example, a wet lamination method, a dry lamination method, a solvent-free dry lamination method, an extrusion lamination method. , T-die coextrusion molding method, coextrusion lamination method, inflation method, etc. Thus, in the present invention, when performing the above-mentioned lamination, if necessary, pretreatment such as corona treatment and ozone treatment can be applied to the film, and for example, isocyanate (urethane) And other known anchor coating agents such as polyethyleneimine, polybutadiene, and organic titanium, or polyurethane, polyacrylic, polyester, epoxy, polyvinyl acetate, cellulose, and other adhesives for lamination. An anchor coat agent, an adhesive agent, etc. can be used.

  As a method of providing a perforation, a method of engraving using pulsed laser irradiation is the most preferable method. In particular, when engraving the opening cut on the resin film by laser processing, it is necessary to absorb the laser oscillation wavelength in the resin film. Is the best.

  The easy-open packaging bag according to still another aspect of the present invention is the above-described laminate film, with the seal layer side as an inner surface, folded or overlapped so that the inner layer surface faces, and the peripheral edge thereof. For example, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope-attached seal type, joint-attached seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type It is possible to produce various easy-open packaging bags according to the present invention by heat-sealing according to other heat-sealing forms. In addition, for example, a self-supporting packaging bag (standing pouch) is also possible. In the above, as a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

  In the easy-open packaging bag formed by folding or heat-sealing the laminate film for easy-open packaging bags according to the present invention with the seal layer side as the inner surface, no perforation appears on the surface. Therefore, it is preferable on design design. It also satisfies various functions such as impact resistance, environmental stress cracking resistance, seal stability, aroma retention, storage stability, and easy-openability.

1 is a cross-sectional view of a laminate film for an easily openable barrier packaging bag according to Example 1. FIG. 3 is a cross-sectional view showing a process of a method for manufacturing a laminate film according to Example 1. FIG. It is a figure which shows the method of creating a barrier packaging bag using the laminate film created in Example 1. FIG. It is a figure which shows the method of creating a barrier packaging bag using the conventional laminate film.

  For the purpose of obtaining a laminate film for easy-opening barrier packaging bags that is improved so that perforations do not appear on the outside, a biaxially stretched polyamide film and a non-stretched polypropylene film as a seal layer are formed on a pear surface of aluminum foil. Realized by laminating sequentially, irradiating carbon dioxide laser on the surface of the aluminum foil through the sealing layer from the side where the unstretched polypropylene film is formed, and engraving perforations in the biaxially stretched polyamide film did. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of a laminate film used in a barrier packaging bag according to the present invention.

  With reference to these drawings, a laminate film 1 used in the present invention includes an aluminum foil 2 having a low gloss luster surface 2a and a glossy surface 2b on both sides. A biaxially stretched polyamide film 7 and a non-stretched polypropylene film 8 as a seal layer are sequentially laminated on a pear ground 2 a of the aluminum foil 2. A biaxially stretched polyester film or a polyester / polyamide laminated film 9 is laminated on the glossy surface 2 b of the aluminum foil 2. The biaxially stretched polyamide film 7 is formed with perforations 10 engraved by a carbon dioxide laser irradiated through the unstretched polypropylene film 8.

  The film thickness of the aluminum foil 2 is 5 to 20 μm, the film thickness of the biaxially stretched polyamide film 7 is 10 to 30 μm, the film thickness of the polyolefin film 8 which is the sealing layer is 50 to 100 μm, and the biaxially stretched polyester film or polyester / polyamide. The film thickness of the laminated film 9 is 8 to 25 μm. About the space | interval of the perforation 10, it is preferable that ratio (m1 / m2) of the length of the cut part (m1) of a perforation and a non-cut part (m2) is 1 or more and 3 or less. The length of the non-cut portion (m2) of the perforation is preferably 0.3 mm or more and 3 mm or less. Thereby, preferable transportability and easy openability are obtained. The longer cutting part (m1) is easier to open.

  Next, the manufacturing method of such a laminate film is demonstrated in detail using FIG.

  With reference to FIG. 2 (A), the laminate film 11 is prepared. The laminate film 11 is provided with an aluminum foil 2 having a low-gloss surface 2a and a glossy surface 2b on the front and back. A biaxially stretched polyamide film 7 and an unstretched polypropylene film 8 are laminated in order on the pear ground 2a of the aluminum foil 2. A biaxially stretched polyester film or a polyester / polyamide laminated film 9 is laminated on the glossy surface 2 b of the aluminum foil 2.

  Referring to FIG. 2 (B), a biaxially stretched polyamide is irradiated from the side where the unstretched polypropylene film 8 is formed through the unstretched polypropylene film 8 toward the pear ground 2a of the aluminum foil 2 with a carbon dioxide gas laser. Cut perforations on film 7. At this time, the inventor found that the perforation is not engraved in the opposite case. That is, the biaxially stretched polyamide film 7 and the unstretched polypropylene film 8 are sequentially laminated on the glossy surface 2b of the aluminum foil 2, and the aluminum foil is passed through the unstretched polypropylene film 8 from the side where the unstretched polypropylene film 8 is formed. No perforation is formed on the biaxially stretched polyamide film 7 even when the carbon dioxide laser is irradiated toward the second glossy surface 2b.

  In the latter case, the perforations are formed only in the former case without the formation of perforations, and the pear ground 2a is the back surface made by rolling the foils in contact with each other as described above. As a result of the material structure being crushed in a random direction, light is irregularly reflected and the surface is dull. It is considered that the carbon dioxide laser is irregularly reflected on the pear ground 2a, the energy is accumulated in the biaxially stretched polyamide film 7, and a perforation is engraved in that portion.

  FIG. 3 (A) is a diagram showing a method of making an easy-open barrier packaging bag using the laminate film 1 prepared in the above embodiment. The laminate film 1 includes an aluminum foil 2 having a low-gloss surface 2a and a glossy surface 2b on both sides. A biaxially stretched polyamide film 7 and a non-stretched polypropylene film 8 as a seal layer are sequentially laminated on a pear ground 2 a of the aluminum foil 2. A biaxially stretched polyester film or a polyester / polyamide laminated film 9 is laminated on the glossy surface 2 b of the aluminum foil 2. The biaxially stretched polyamide film 7 is formed with perforations 10 engraved by a carbon dioxide laser irradiated through the unstretched polypropylene film 8.

  With reference to FIG. 3 (B), two laminated films 1 are laminated with the unstretched polypropylene film 8 serving as a sealing layer inside, and heat sealed to form a bag. FIG. 3C is a front view of the obtained barrier bag. FIG. 3B is a cross-sectional view taken along line BB in FIG. According to the present embodiment, the perforation is hidden inside the aluminum foil 2 and does not appear outside, which is preferable in terms of design. On the other hand, although it is hidden inside, there is a perforation, so it can be easily opened at this part.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the easily openable barrier packaging bag of the present invention, the perforation does not come out on the surface of the bag, which is preferable in terms of design design.

DESCRIPTION OF SYMBOLS 1,11 Laminated film 2 Aluminum foil 3 Polyethylene film 4 PET film 5 Perforation 6 Low density polyethylene film 7 Biaxially stretched polyamide film 8 Unstretched polypropylene film 9 Biaxially stretched polyester film or polyester / polyamide laminated film 10 Perforation

Claims (3)

An aluminum foil having a low-gloss pear ground and a glossy surface on the front and back,
A biaxially stretched polyamide film and a sealing layer sequentially laminated on the pear ground of the aluminum foil,
A biaxially stretched polyester film or a polyester / polyamide laminated film laminated on the glossy surface of the aluminum foil,
A laminate film for an easily openable barrier packaging bag in which perforations are formed in the biaxially stretched polyamide film. Laminated on the glossy surface of the aluminum foil, low-gloss pear ground and aluminum foil having a glossy surface on the front and back, biaxially stretched polyamide film and seal layer sequentially laminated on the pear ground of the aluminum foil Preparing a laminated film having a biaxially stretched polyester film or a polyester / polyamide laminated film;
A step of irradiating a carbon dioxide laser toward the pear ground of the aluminum foil through the seal layer from the side where the seal layer is formed, and engraving perforations in the biaxially stretched polyamide film. For producing laminated film for conductive barrier packaging bag.   An easy-open barrier packaging bag, wherein the laminate film for easy-open barrier barrier bag according to claim 1 is bent or overlapped and heat-sealed with the seal layer side as an inner surface.