WO2007036980A1

WO2007036980A1 - Gas barrier laminated film

Info

Publication number: WO2007036980A1
Application number: PCT/JP2005/017706
Authority: WO
Inventors: Hiroshi Suzuki; Ryukichi Matsuo; Noboru Sasaki
Original assignee: Toppan Printing Co., Ltd.
Priority date: 2005-09-27
Filing date: 2005-09-27
Publication date: 2007-04-05
Also published as: CN101065240A; CN101065240B; JPWO2007036980A1

Abstract

A gas barrier laminated film which has a polymer film substrate, a gas barrier vapor deposition layer of an inorganic compound formed on one surface of the polymer film substrate, and a gas barrier coating layer formed on the gas barrier vapor deposition layer, characterized in that the film has such an oxygen barrier property that an oxygen permeability of the film after stretched by 5 % is 1.5 times or less as large as that before the stretching.

Description

Specification

Gas barrier laminated film

Technical field

[0001] The present invention relates to a gas noreia laminated film used in the packaging field of foods, pharmaceuticals and the like.

Background art

[0002] In recent years, packaging materials used for packaging foods, pharmaceuticals, etc. have been used to suppress the alteration of the contents and to maintain the efficacy of oxygen, water vapor, and other gases that alter the contents of the packaging material. It is necessary to prevent the influence of the gas, and it is required to have gas noria properties that block the permeation of these gases.

[0003] For example, in the case of pharmaceutical products that inhibit the oxidation and alteration of proteins and oils and fats, and maintain the taste and freshness of foods, and in pharmaceutical products that require handling in aseptic conditions, In order to suppress deterioration and maintain efficacy, these packaging materials are required to have gas barrier properties.

[0004] For this reason, it has been conventionally considered that polybulal alcohol (PVA), ethylenebulualcohol copolymer (EVOH), or polysalt vinylidene resin (PVDC) is generally relatively high in gas noliativity. A gas-nolia laminated film obtained by laminating or coating a polymer resin composition is generally used as a packaging film. In addition, alone, it has high gas noria! / Wow! /, Metal vapor deposition films obtained by depositing metal or metal compounds such as aluminum (A1) on polymer resin compositions, and recently, silicon oxide (SiO 2) thin films such as silicon monoxide (SiO),匕 Magnesium (MgO) thin film with high transparency

X

Vapor-deposited films deposited on substrates that also have molecular material strength have been developed. These have superior gas noreia properties than gas noble materials made from a high molecular weight resin composition alone, and are less susceptible to deterioration under high humidity. Has begun to be used.

[0005] However, gas- noria laminated films using the above-described PVA and EVOH polymer resin compositions have a large temperature dependency and humidity dependency. Deterioration of the subbarrier property is observed, in particular, the water vapor nore property is lowered, and depending on the packaging application, the gas nore property may be remarkably lowered by boiling or retort treatment.

[0006] In addition, a gas noreia laminated film using a PVDC-based polymer resin composition has a low humidity dependency but a high gas noreia material having an oxygen noreer property of lcm ³ / m ² .day 'atm or less. It is difficult to realize (high gas nolia material). In addition, PVDC-based polymer resin compositions contain a large amount of chlorine, which causes problems in waste disposal such as incineration and recycling.

[0007] Further, the above-mentioned metal vapor-deposited film on which a metal or a metal compound is vapor-deposited, a silicon oxide thin film such as silicon monoxide (Si 2 O), or a vapor-deposited film on which a magnesium oxide (MgO) thin film is vapor-deposited are used as a gas nore layer. The thin film of inorganic compound is inflexible, weak against stagnation and bending, and has poor adhesion to the substrate, so it needs to be handled with care, especially after packaging materials such as printing, laminating and bag making. If a crack is generated during processing and the gas noria property is significantly lowered, there is a problem.

[0008] In addition, since a vacuum process such as a vacuum deposition method, a sputtering method, or a plasma chemical vapor deposition method is used as a forming method, the apparatus is expensive, and the substrate is locally heated in the forming process, causing damage to the substrate. May cause defects, pinholes, etc. in the inorganic thin film due to decomposition, degassing, etc. of low molecular weight parts or additive parts such as plasticizers. It has the problem of becoming expensive.

[0009] To solve the above problems, as described in Japanese Patent Application Laid-Open No. 62-295931, a gas nolia material in which a metal alkoxide film is formed on a base material has been proposed. Since this gas barrier material has a certain degree of flexibility and can be manufactured by a liquid phase coating method, it can also be reduced in cost.

[0010] However, although the gas noria material has a certain degree of improvement in gas noria properties compared to the case of a single substrate, it cannot be said that the gas noria properties are still sufficient. Disclosure of the invention

[0011] Therefore, the present invention is a gas-nore laminate film that is excellent in gas-nore property, has excellent flexibility, and can suppress degradation of gas-no-reality even when the film is stretched. The purpose is to provide a program.

[0012] According to one aspect of the present invention, a polymer film substrate, a gas barrier inorganic vapor deposition layer formed on one surface of the polymer film substrate, and the gas barrier inorganic vapor deposition layer are formed. In a gas nore laminate film having a gas nore coat layer, the oxygen permeability when the laminate film is stretched 5% is not more than 1.5 times the oxygen permeability before stretch. There is provided a gas-noria laminated film characterized by having noria properties.

[0013] The gas-nolia laminated film according to one embodiment of the present invention has a water vapor permeability such that the water vapor permeability when the laminated film is stretched by 2% is not more than 1.5 times the water vapor permeability before stretching. Has barrier properties.

[0014] As the polymer film substrate, a polyethylene terephthalate film can be used.

[0015] As the gas barrier coating layer, a layer mainly composed of an aqueous polymer having a hydroxyl group can be used. As the water-based polymer, polybulal alcohol, ethylenebulal alcohol copolymer, and those containing at least one selected from the group strength of cellulose strength can be used.

[0016] Further, as the gas nore coating layer, a layer mainly composed of a composite material composed of a metal alkoxide and Z or a hydrolyzate thereof and an aqueous polymer having a hydroxyl group can be used. As the metal alkoxide, a silicon alkoxide can be used.

[0017] Further, the gas noriotic coating layer may contain a silane coupling agent.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a configuration of a gas barrier laminate film according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the degree of elongation and the oxygen permeability of the gas barrier laminate films of Example 1 and Comparative Example 1.

FIG. 3 is a graph showing the relationship between the degree of elongation and the water vapor transmission rate of the gas barrier laminate films of Example 1 and Comparative Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the invention will be described. FIG. 1 is a schematic view illustrating the configuration of a gas noreia laminated film according to an embodiment of the present invention.

In FIG. 1, a gas barrier laminate film 1 is formed by sequentially laminating a gas norelic inorganic vapor deposition layer 3 as a first layer and a gas nore coat layer 4 as a second layer on a substrate 2. Has been.

[0021] The substrate 2 is in the form of a sheet or a film, and is a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate, a polyamide such as nylon 6 or nylon 66, a poly What is normally used as a packaging material, such as butyl chloride, polyimide, or a copolymer of these polymers, can be appropriately selected depending on the application.

[0022] To the polymer resin material constituting the substrate 2, for example, known additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant, and a colorant are appropriately added as necessary. I can do it. Further, the surface of the substrate 2 can be subjected to surface modification such as corona treatment or anchor coating treatment to improve the adhesion of the coating.

[0023] The first gas noble inorganic deposition layer 3 formed on the substrate 2 is made of an oxide, nitride, or fluoride of silicon, aluminum, titanium, zirconium, tin, magnesium, or the like. These are formed by a vacuum process such as a vacuum deposition method, a sputtering method, or a plasma vapor deposition method (CVD method). In particular, acid-aluminum is colorless and transparent, has excellent characteristics such as boil and retort resistance, and can be used in a wide range of applications.

[0024] The thickness of the gas barrier inorganic vapor-deposited layer 3 varies depending on the application and the thickness of the second layer, but it is desirable that the force of several nm is in the range of 500 nm. If the thickness is less than 5 nm, there is a problem in the continuity of the thin film, and if it exceeds 300 nm, cracks occur and the flexibility decreases immediately, so 5ηπ! ~ 30 Onm.

[0025] The second gas noble coating layer 4 formed on the gas barrier inorganic vapor deposition layer 3 is formed by using a coating agent mainly composed of an aqueous solution containing an aqueous polymer or a water Z alcohol mixed solution. The Alternatively, a coating agent mainly composed of an aqueous solution or water Z alcohol mixed solution containing an aqueous polymer and one or more metal alkoxides or hydrolyzed products thereof. Formed using. Specifically, it is formed by coating such a coating agent on the surface of the inorganic thin film layer 3 on the substrate 2 and drying by heating.

[0026] The aqueous polymer used as a coating agent for forming the gas nore coating layer 4 is a polymer having a hydroxyl group in the molecule, and is not necessarily limited to a water-soluble polymer. For example, those having an affinity for water, such as Emulsion.

[0027] Examples of the aqueous polymer include polybulal alcohol, polybulurpyrrolidone, denpene, methylcellulose, carboxymethylcellulose, sodium alginate, an ethylenebulalcohol copolymer, acrylic resin such as polyacrylic acid and polymethacrylic acid, These acrylic resin resins can be mentioned, and particularly, when a polyvinyl alcohol (hereinafter referred to as PVA) is used as a coating agent, the gas nooricity is most excellent. The PVA here is generally obtained by saponifying polyvinyl acetate, and several tens of percent of acetate groups remain. V, a partly partially saponified PVA. V ヽ Completely saponified, including up to PVA, not particularly limited! /.

[0028] The metal alkoxide includes tetraethoxysilane [Si (OCH)], triisopropoxyaluminum.

2 5 4

It is represented by the following general formula, such as -um [8 1 (0 2'-ji H)].

3 7 3

[0029] M (OR) (wherein M represents a metal such as Si, Ti, Ai or Zr, and R represents an n 3 2 5 alkyl group such as CH or CH)

Of these, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

[0030] When the coating agent contains a metal alkoxide or a hydrolyzate thereof, the gas barrier coating layer 4 contains a composite material of an aqueous polymer and a metal alkoxide or a hydrolyzate thereof. Thus, the water resistance of the gas barrier coating layer 4 can be improved by using a metal alkoxide.

[0031] A silane coupling agent can be added to the coating agent. Thereby, the heat resistance of the formed gas barrier coating layer 4 is increased, and even when the gas barrier laminated film is used for packaging of a boiled product or a retort product, it is possible to suppress a decrease in the barrier property.

[0032] In addition, the coating agent has a range that does not impair the barrier property of the gas barrier coating layer 4, and is usually a filler, a lubricant that imparts slipperiness to the film, a colorant, a leveling agent, a purple color. Known additives such as external line absorbers, antioxidants, dispersants, stabilizers, viscosity modifiers, and colorants can be added.

[0033] Furthermore, an inorganic layered compound such as montmorillonite or smectite can be added to the coating agent in order to give the gas nore coating layer 4 itself nore nature.

[0034] Conventionally known means such as a dating method, a roll coating method, a screen printing method, and a spray method are used for the coating method. The film thickness varies depending on the type of coating agent. The thickness after drying may be in the range of about 0.01 to LOO / z m. If it is 50 / z m or more, cracks are likely to occur in the film, so 0.01 to 50 m is desirable.

[0035] It should be noted that some reaction layer is formed between the gas noble inorganic vapor deposition layer 3 and the coating formed by application of the coating agent, or a pinhole in which this coating is formed in the gas barrier inorganic vapor deposition layer 3. In addition, a dense structure is formed by filling and reinforcing defects such as cracks and grain boundaries, or micropores, which serve as a protective layer for improving the gas barrier property and for the gas barrier inorganic vapor deposition layer.

[0036] In the case where the main component is an inorganic component having a coating agent strength, a metal alkoxide force, and an aqueous polymer such as PVA, the gas nooriety can be improved by the following mechanism. That is, the inorganic component composed of metal alkoxide undergoes hydrolysis and polycondensation reaction in solution to form a chain or three-dimensional toothpick polymer, and the polymerization proceeds further by evaporation of the solvent upon drying and heating. It is considered to form a complex at the molecular level with aqueous polymers. Therefore, silica sol (silica silicate (water glass) with fine particles such as silica (SiO 2) with a specific particle size can be obtained.

2

It is different from those obtained by simply dispersing fine particles such as colloidal silica.

[0037] Further, on the gas nore laminate film according to the present embodiment, a thermoplastic resin layer and a print layer that can be heat-sealed as necessary are provided on the gas nore coating layer 4 or the substrate 2. In addition, it is possible to stack a plurality of resins via an adhesive layer.

[0038] Usually, processing such as printing and laminating on a packaging material is performed by unwinding the film on a machine, so that tensile stress is applied, and cracks are easily generated in the gas barrier vapor deposition layer. However, the gas-nootropic laminated film according to one embodiment of the present invention described above is Since the decrease in barrier properties when stretched is small, the barrier properties that were initially retained are almost maintained even when printing on films or processing such as pasting with other films, resulting in high barrier properties. Certain packaging materials can be provided.

[0039] As described above, the gas barrier vapor deposition layer 3 with the inorganic compound strength is used as the first layer on the base material 2 with the polymer resin composition strength, and the aqueous polymer (or the composite of the aqueous polymer and the metal alkoxide). The gas noble laminate film according to the present embodiment obtained by laminating the gas nore coating layer 4 containing the union) as the second layer has high gas nooriness and is flexible, laminate strength, and water resistance. Excellent in heat resistance, moisture resistance, and boil-retort resistance, and even when laminated with other resins, its strength is sufficient for practical use. In other words, even under high-temperature and high-humidity atmospheres, long-term storage is possible without deteriorating contents such as foods and pharmaceuticals that do not impair gas barrier properties. Furthermore, since the oxygen permeability when the laminated film is stretched by 5% is 1.5 times or less of the oxygen permeability before stretching, it can be used as a packaging material in post-processing such as laminating and bag making. It has an excellent effect that it does not impair the gas properties.

[0040] Specific examples of the gas noble laminated film of the present invention will be described below.

[Example 1]

Aluminum oxide was deposited on the top surface of a 12 m-thick polyethylene terephthalate substrate to a thickness of 15 nm. Further, tetraethoxysilane [Si (OC H):

2 5 4

TEOS) and a coating agent containing poly (bull alcohol) is applied with a bar coater and dried at 120 ° C for 1 minute in a dryer to form a film with a thickness of about 1 μm. Obtained.

[Comparative Example 1]

Aluminum oxide was deposited on the upper surface of a 12 m-thick polyethylene terephthalate substrate to a thickness of 15 nm to obtain a gas nore laminate film.

[0043] The gas barrier laminated films according to Example 1 and Comparative Example 1 were stretched in the longitudinal direction, and the gas barrier properties after stretching were determined and compared. That is, the gas nootropic laminated film was stored under constant temperature and humidity of 40 ° C.-90% RH for 4 weeks, and the gas barrier properties before and after that were evaluated by measuring oxygen permeability and water vapor permeability. Oxygen barrier properties at 25 ° C—100% RH atmosphere Measured using a permeability measurement device (MOCON OXTRAN 10Z40A manufactured by Modern Control), and measured the water vapor barrier property using a water vapor permeability measurement device (PERMATRAN W6 manufactured by Modern Control) in an atmosphere of 40 ° C-90RH. . The results are shown in Table 1 and Table 2 below.

Table 1 shows the oxygen barrier properties after elongation, and Table 2 shows the water vapor permeability barrier properties after elongation. 2 and 3 plot Table 1 and Table 2 with the degree of elongation on the horizontal axis and the degree of transmission on the vertical axis.

[Table 1] Table 1

[Table 2]

Table 2

[0045] From Table 1 and FIG. 2, the laminated film according to Example 1 has almost no increase in oxygen permeability even at 5% elongation, whereas the laminated film according to Comparative Example 1 has 5 It can be seen that the oxygen permeability rapidly increased 20 times and the oxygen norality decreased at the elongation of%.

[0046] Further, from Table 2 and FIG. 2, the laminated film according to Example 1 hardly increased the water vapor permeability even at an elongation of 2%, whereas the laminated film according to Comparative Example 1 At 2% elongation, the water vapor permeability increases abruptly 10 times, indicating that the water vapor barrier properties are reduced.

Industrial applicability

[0047] The gas barrier laminate film of the present invention maintains excellent gas permeability even after stretching due to the formation of a gas nore coating layer on the gas noble vapor deposition layer, so printing, laminating, It can be applied as a packaging material for foods, pharmaceuticals, etc., whose gas barrier properties do not deteriorate even when processing bags, etc., and its range of use is wide.

Claims

The scope of the claims

[1] A polymer film substrate, a gas barrier inorganic vapor deposition layer formed on one surface of the polymer film substrate, and a gas barrier coating layer formed on the gas barrier inorganic vapor deposition layer The gas-nolia laminated film has an oxygen barrier property such that the oxygen permeability when the laminated film is stretched by 5% is not more than 1.5 times the oxygen permeability before stretching. Gas noria laminated film.

[2] The water vapor barrier property according to claim 1, wherein the water vapor permeability when the laminated film is stretched by 2% is not more than 1.5 times the water vapor permeability before stretching. Gas barrier laminate film.

[3] The gas barrier laminate film according to [1], wherein the polymer film substrate is a polyethylene terephthalate film.

[4] The gas noreia laminate film according to [1], wherein the gas barrier coating layer is mainly composed of an aqueous polymer having a hydroxyl group.

[5] The aqueous polymer contains at least one selected from the group force consisting of polybulal alcohol, ethylenebulalcohol copolymer, and cellulose strength.

4. The gas barrier laminate film according to 4.

[6] The gas barrier coating layer according to claim 1, wherein the gas barrier coating layer is mainly composed of a composite material composed of a metal alkoxide and Z or a hydrolyzate thereof, and an aqueous polymer having a hydroxyl group. Gas nore laminated film.

7. The gas barrier laminate film according to claim 6, wherein the metal alkoxide is a silicon alkoxide.

8. The gas barrier laminate film according to claim 6, wherein the gas noble coating layer further contains a silane coupling agent.