JP2003053922A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent gas barrier film excellent in gas barrier properties and also excellent in stress crack resistance and not deteriorated in gas barrier properties in a printing process, a lamination process and a bag making process all of which use the gas barrier film and various processes of the filling, preservation transport or the like content. SOLUTION: The gas barrier film is constituted by providing a layer 2 having absorbed a substance comprising a turmeric at least on the single surface of a substrate 1 comprising a nylon resin film, and the density of the layer 2 having absorbed the substance comprising the turmeric is made higher than that of the substrate before absorption by 0.1-1.0 g/cm<3> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging film used in the field of packaging non-food products such as foods or pharmaceuticals, electronic parts, etc., and more particularly, by suppressing the permeation of gases such as oxygen and water vapor. The present invention relates to a film having a gas barrier property that suppresses the oxidation, decomposition, and alteration of the.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods and non-foods contain oxygen, water vapor, etc. which permeate the packaging materials in order to suppress alteration of contents and to retain their functions and properties. It is necessary to prevent the influence of a gas that modifies the contents, and it is required to have a gas barrier property of blocking these gases.

As a conventional gas barrier material, a film in which a resin having excellent gas barrier properties such as polyvinyl alcohol, ethylene / vinyl alcohol copolymer, polyvinylidene chloride and polyacrylonitrile is coated on the surface of a substrate film, or these resins The single film or the multi-layer film laminated with other resin, and the vapor deposition film obtained by vapor deposition of aluminum foil, metallic aluminum, silicon oxide, aluminum oxide, etc. have been mainly used.

[0004]

However, a film coated with a gas-barrier resin, a single film of these gas-barrier resins or a multilayer film laminated with another resin has a high temperature-humidity dependency and maintains a high gas-barrier property. In addition, there is a problem that a film using polyvinylidene chloride or polyacrylonitrile may generate a harmful substance when it is discarded or incinerated. Further, although the aluminum foil has excellent gas barrier properties, there is a problem that a large amount of non-combustible clumps remain when the packaging material is disposed of after use or incinerated. Further, the film formed by depositing an inorganic oxide such as metallic aluminum, silicon oxide, or aluminum oxide has a defect such as poor stress crack resistance.

An object of the present invention is transparent and excellent in gas barrier property, and in various processes such as printing process, laminating process, bag-making process, and filling, storing and transporting contents.
An object of the present invention is to provide a gas barrier film which has excellent stress crack resistance and does not deteriorate in gas barrier property.

[0006]

The invention according to claim 1 of the present invention is characterized by comprising a base material made of a nylon resin film, and a layer on which a substance made of turmeric is adsorbed, provided on at least one surface of the base material. It is a gas barrier film.

Next, in the invention according to claim 2, in the invention according to claim 1, the density of the layer on which the substance composed of turmeric is adsorbed is 0.1 to 10% lower than the density of the base material before adsorption.
The gas barrier film is characterized in that it increases in the range of 1.0 g / cm ³ .

[0008]

According to the present invention, the nylon resin film used as the base material is coated with a substance composed of turmeric and is provided with a layer permeated and adsorbed. Therefore, the density of the turmeric adsorption layer is different from that of the base material before adsorption. By increasing the density, the gas barrier property is improved, and even in various post-processes using this film that adsorbs turmeric, the original flexibility is not impaired and excellent gas barrier property is maintained. it can.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The gas barrier film of the present invention will be described in detail below with reference to embodiments.

FIG. 1 is a side sectional view of a gas barrier film 10 showing an embodiment of the present invention. A substrate 2 made of a nylon resin film is provided with a layer 2 on one side of which a substance made of turmeric is adsorbed. .

The resin used for the substrate 1 is ε-
Nylon 6 obtained by ring-opening polymerization reaction of caprolactam,
Resins such as nylon 66 obtained by polycondensation reaction of hexamethylenediamine and adipic acid salt, MXD6 nylon obtained by polycondensation of metaxylenediamine and adipic acid, and nylon 12 are used.

The nylon resin film used as the substrate 1 may contain various additives and stabilizers such as an antistatic agent, an anti-UV agent, a plasticizer, a lubricant, etc., so that the adhesion is improved. Therefore, the surface may be subjected to corona treatment, low temperature plasma treatment, or ion bombardment treatment as pretreatment.

The thickness of the nylon resin film used as the base material 1 is not particularly limited, but in consideration of suitability as a packaging material and workability when laminating other layers, it is 5 to 100 μm. Is preferable, and more preferably 10 to 30 μm.

The turmeric refers to a perennial herb of the ginger family or its rhizome (turmeric). Its components are curcumin 0.3%, essential oils 5-6, and others. Commonly used applications are medicines such as aromatic bitterness, diuretics, drugs for treating liver diseases, curry powder and food coloring. , Directly used for dyes.

When the turmeric is adsorbed on the base material 1, the penetration depth of the substance composed of turmeric adsorbed on the base material 1 depends on the turmeric concentration of the coating liquid, the temperature at which it is adsorbed, and the adsorbing time. Changes variously. In the present invention, the density of the layer 2 on which turmeric is adsorbed needs to be higher than the density of the base material 1 before adsorption within the range of 0.1 to 1.0 g / cm ³ . The gas barrier property is further improved by increasing the density as described above.

The method of adsorbing the turmeric on the substrate 1 is as follows.
A coating solution obtained by dissolving turmeric in a toluene solvent in an amount of 10 to 30% by weight is applied to the surface of the base material 1 by using a clavia or roll coater machine, adsorbed in the base material 1 and then dried at 120 ° C. , Roll up and create. At this time, turmeric permeates in the thickness direction of the substrate 1 and is adsorbed.

It is also possible to laminate various sealant layers on the gas barrier film 10 of the present invention via an adhesive agent layer, and the adhesive layer is generally a main agent having a hydroxyl group and a curing agent having an isocyanate group. The two-component reactive adhesive which is used by mixing two adhesive components or the one-component adhesive which is solely used the adhesive component having an isocyanate group at the end is mainly used. Can be applied by a known clavia coating method, roll coating method, or the like. The amount of adhesive applied is 1 to 5 g / m ² (dry state).

The sealant layer is used for a heat-sealing portion when forming a bag-like package or the like using the laminate, and includes, for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene- Methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, laminating resins such as ethylene-acrylic acid ester copolymer by melt extrusion method,
Films made of the various resins described above are laminated by a method such as sand lamination through an adhesive resin.

[0019]

EXAMPLES The gas barrier film of the present invention will be described below based on specific examples.

<Example 1> Thickness 1 used as substrate 1
5μm biaxially stretched nylon 6 film (density 1.15g
/ Cm ³ ), a coating solution in which turmeric is dissolved in a toluene solvent in an amount of 20% by weight is applied to one surface using a gravure coater and is adsorbed to form a layer 2 in which turmeric is adsorbed.
The density of the layer 2 adsorbing the turmeric is 2.15 g / cm.
The gas barrier film 10 of the present invention was prepared by adsorbing it to the state of ³ and then drying and winding.

Comparative Example 1 A single film of biaxially stretched nylon 6 film having a thickness of 15 μm was used as a gas barrier film for comparison.

Comparative Example 2 Using a coextrusion film forming machine, a film having a total thickness of 15 μm and having a three-layer structure of nylon 6 resin / ethylene / vinyl alcohol copolymer resin / nylon 6 resin was prepared. A gas barrier film was created.

<Evaluation> The gas barrier films of Example 1 and Comparative Examples 1 and 2 were used to measure the oxygen permeability and water vapor permeability before and after the Gelvo Fuchs test, and the puncture strength was measured by the following measuring methods. The results are shown in Table 1. (1) Gelbo flex test method Using a gelbo flex tester (manufactured by Rigaku Kogyo Co., Ltd., twisting angle of 440 degrees, conforming to ASTM F-392), the prepared gas barrier film was subjected to repetitive motion five times in a room temperature environment. After that, the oxygen permeability and the water vapor permeability were measured by the methods (2) and (3). (2) Oxygen permeability measurement method Modern Control Co. (MOCON OXTRAN,
10/50 A) and was measured at 25 ° C. in a 65% RH atmosphere. (3) Water vapor transmission rate measurement method Modern Control Co. (MOCON PERMATR
AN, W6 type) was used and the measurement was performed at 40 ° C. in a 90% RH atmosphere. (4) Puncture strength measurement method The prepared film was fixed, and the film surface had a diameter of 1.
0 mm, a semicircular needle with a tip shape radius of 0.5 mm is 5 per minute
Puncture was performed at a speed of 0 ± 0.5 mm, and the load until the needle penetrated was used to evaluate the quality.

[0024]

[Table 1]

From the results shown in Table 1, Example 1 has no change in oxygen permeability and water vapor permeability before and after the Gelboflex test, has excellent stress crack resistance, and has a strong puncture strength. On the other hand, since Comparative Example 1 does not have a layer in which turmeric is adsorbed, both the oxygen permeability and the water vapor permeability are inferior to those of Example 1. Comparative Example 2 is excellent in oxygen permeability and water vapor permeability, but has a drawback that the puncture strength is small, holes are opened in an acute-angled portion such as contents, and the gas barrier property is impaired.

[0026]

The gas barrier film of the present invention has a layer made by adsorbing a substance made of turmeric on a substrate made of a nylon resin film, so that the film itself does not lose its flexibility. It has excellent stress crack resistance in various processes using the gas barrier film after adsorption of turmeric, and also has high gas barrier property. A laminate obtained by laminating a sealant layer via an adhesive layer on this gas barrier film is a packaging material that does not deteriorate in gas barrier property even under various stresses, and can maintain high gas barrier property. Widely available in the field.

[Brief description of drawings]

FIG. 1 is a side sectional view of a gas barrier film of the present invention.

[Explanation of symbols]

1 ... Base material 2 ... Layer that adsorbs turmeric substance 10 ... Gas barrier film

Claims (2)

[Claims] 1. A gas barrier film comprising a base material made of a nylon resin film and a layer having a substance made of turmeric adsorbed on at least one surface thereof. 2. The density of the layer on which the substance comprising turmeric is adsorbed is 0.1 to 1.0 g / c of the density of the base material before adsorption.
The gas barrier film according to claim 1, wherein the gas barrier film is increased in the range of m ³ .