JP2004202822A - Gas barrier film and gas barrier package using the film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier film used as a packaging film which inhibits change in quality or deterioration of contents such as foodstuff, pharmaceuticals, electronic members, electronic equipment and the like due to oxygen, steam or the like and also maintains high gas barrier properties in retorting or boiling treatment, and a package using this gas barrier film. <P>SOLUTION: The gas barrier film is characterized by providing a layer, which is composed of a hydroxyl-containing polymeric material (A) and at least one kind of a component (B) selected from polyacrylic acid or its partially neutralized product and polymethacrylic acid or its partially neutralized product, on one surface of a plastic film substrate and also providing a ceramic vapor-deposited layer on the other surface thereof. The package using the gas barrier film is also disclosed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４８】
【表２】

【００４９】
表１及び２から明らかに、本発明の構成のガスバリフィルム（実施例１〜１０）は、いずれもレトルト処理もしくはボイル処理後でも高いバリア性を保持している。これに対して、比較例１及び２は水蒸気バリア性をあるレベルまで保持しているものの、酸素バリア性は著しく低下している。また、比較例４は酸素バリア性を保持するものの、水蒸気バリアに関しては基材並（比較例５）である。ナイロン基材の場合にもほぼ同様の結果である。
【００５０】
【発明の効果】
本発明によれば、レトルト処理やボイル処理などのような過酷な処理工程を経ても酸素バリア性及び水蒸気バリア性を高いレベルで保持することのできるガスバリアフィルム及びそれを用いた包装体を提供することができる。
従って、内容物を酸素や水蒸気等によって変質や劣化を防止する必要のある食品、医薬品、電子部材、電子機器等の包装分野の包装用フィルム及び包装体として好適に用いられるものである。
【図面の簡単な説明】
【図１】本発明のガスバリアフィルムの構成の一例を示す断面図である。
【符号の説明】
１・・・ガスバリアフィルム
２・・・プラスティックフィルム基材層
３・・・水酸基含有高分子体（Ａ）と、成分（Ｂ）とからなる層
４・・・セラミックス蒸着層
５・・・複合被膜[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas barrier film. More specifically, the present invention relates to a gas barrier film and a gas barrier package suitable as a packaging film for preventing contents such as foods, medicines, electronic members, and electronic devices from being altered or deteriorated by oxygen, water vapor, or the like.
[0002]
[Prior art]
Various functions are required for packaging materials. Among them, content protection is the most important function. Deterioration and alteration of the contents are promoted mainly by the influence of oxygen, moisture, light, heat and the like. In particular, the influence of oxygen and moisture is great. It is important to shield them from the viewpoint of protecting the contents, that is, the presence of a gas barrier film is required. In addition, under the circumstances where tastes are diversified and additives are regulated as in today, not only blocking from the outside, but also inert gas filling packaging, prevention of deterioration of flavor and aroma, etc. It is necessary to block transmission.
[0003]
However, plastic films generally have poor gas barrier properties, and when used alone, there is nothing that satisfies the requirements except for some uses. Therefore, a method of forming a gas barrier film by laminating another layer having excellent gas barrier properties is often adopted.
[0004]
It is known that a resin having a layer containing polyvinyl alcohol as a component has a high crystallinity and excellent oxygen barrier properties in a dry state, but has a low crystallinity under high humidity conditions. There is a problem that it is significantly reduced (for example, see Patent Documents 1, 2, and 3).
[0005]
Various methods have been devised to improve the above problems. A gas barrier film provided with a polyvinylidene chloride layer has been put into practical use as a non-hydroxyl group, but harmful dioxins may be generated during disposal treatment (for example, see Patent Document 4). Further, to improve the water resistance of polyvinyl alcohol, the effect of poly (vinyl alcohol-co-ethylene) or the like in which an ethylene unit is introduced into polyvinyl alcohol is also known, but its resistance to humidity dependence is still insufficient. (See, for example, Patent Documents 5 and 6).
[0006]
Further, a composite coating of a polyacrylic resin salt and polyvinyl alcohol has been devised, and is known to have excellent oxygen barrier properties, but does not exhibit water vapor barrier properties (for example, see Patent Document 7). Gas barrier films provided with a ceramic vapor deposition layer are also sold by various companies, but the barrier properties may be insufficient depending on the application. Further, when the retort treatment is performed, the oxygen barrier property may be slightly impaired (for example, see Patent Document 8).
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 7-41685 [Patent Document 2]
JP-A-7-33909 [Patent Document 3]
JP-A-7-251475 [Patent Document 4]
JP-A-55-59961 [Patent Document 5]
JP-A-6-293118 [Patent Document 6]
JP-A-11-170430 [Patent Document 7]
JP 2001-164174 A [Patent Document 8]
JP-A-6-16848
[Problems to be solved by the invention]
The present invention has been made in order to solve the above problems, and suppresses the contents of foods, pharmaceuticals, electronic members, electronic devices, and the like from being altered or deteriorated by oxygen, water vapor, or the like. It is an object of the present invention to provide, as a packaging film, a gas barrier film that maintains high gas barrier properties even in retort treatment and boil treatment, and a package using the same.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, that is, the invention according to claim 1 is to provide a hydroxyl group-containing polymer (A), polyacrylic acid or a partially neutralized product thereof, polymethacrylic acid or A gas barrier film comprising a layer comprising at least one or more components (B) selected from the partially neutralized product, and a ceramic vapor deposition layer provided on the other surface.
[0010]
Further, the invention according to claim 2 is that the plastic film substrate comprises at least one of polyolefin, polyester, polyamide, polyimide, cellulose, acrylic resin, polyethersulfone, polylactic acid, and polyvinyl alcohol as a component and / or a copolymer. The gas barrier film according to claim 1, wherein the gas barrier film has a coalescing component.
[0011]
The invention according to claim 3 is characterized in that the hydroxyl group-containing polymer has at least one of polyvinyl alcohol, starch, and cellulose as a component and / or a copolymer component. Gas barrier film.
[0012]
The invention according to claim 4 is characterized in that the partially neutralized product of polyacrylic acid or the partially neutralized product of polymethacrylic acid is an alkali metal salt and / or an alkaline earth metal salt. The gas barrier film according to any one of claims 1 to 3.
[0013]
The invention according to claim 5 is characterized in that the ceramic deposited layer is made of any one of aluminum oxide, silicon oxide, and magnesium oxide, or a mixture thereof. Gas barrier film.
[0014]
The gas barrier film according to any one of claims 1 to 5, wherein the surface of the plastic film substrate on which the ceramic deposition layer is laminated is subjected to a plasma treatment. .
[0015]
Further, in the invention according to claim 7, the plasma processing uses at least one of argon, nitrogen, and oxygen as a plasma gas type, sets a plasma bias value to 100 V or more, and Eb = bias value / The gas barrier film according to claim 6, wherein the low-temperature plasma treatment is performed with an Eb value defined by (film width x processing speed) of 200 [Vsm- ² ] or more.
[0016]
The invention according to claim 8 is the gas barrier film according to claim 6, wherein the plasma processing is a reactive ion etching mode plasma processing.
[0017]
The invention according to claim 9 is the gas barrier film according to any one of claims 1 to 8, wherein the plasma treatment or the ceramic deposition is performed in an in-line process.
[0018]
The invention according to claim 10 is characterized in that a composite coating having a hydrolyzate of polyvinyl alcohol and a metal alkoxide as a component is provided on the ceramic vapor deposition layer. Item 10. The gas barrier film according to item 9.
[0019]
The invention according to claim 11 is the gas barrier film according to claim 10, wherein the metal alkoxide is a silane alkoxide and / or a silane coupling agent.
[0020]
According to a twelfth aspect of the present invention, there is provided a package formed by using the gas barrier film according to any one of the first to eleventh aspects.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a sectional view showing an example of the configuration of the gas barrier film of the present invention.
As shown in FIG. 1, a gas barrier film 1 of the present invention comprises a plastic film substrate 2 having a hydroxyl group-containing polymer (A), polyacrylic acid or a partially neutralized product thereof, polymethacrylic acid or a portion thereof on one surface thereof. A layer 3 comprising at least one or more components (B) selected from neutralized products is provided, and a ceramic vapor deposition layer 4 is provided on the other side, and a polyvinyl alcohol and a metal alkoxide are further provided on the ceramic vapor deposition layer 4. And a composite film 5 having a hydrolyzate as a component. The composite coating 5 is provided as needed.
[0022]
The plastic film substrate 2 used in the present invention preferably has at least one of polyolefin, polyester, polyamide, polyimide, cellulose, acrylic resin, polyethersulfone, polylactic acid, and polyvinyl alcohol as a component and / or a copolymer component. . Particularly, polyethylene terephthalate and nylon are suitable, but not necessarily limited. Practically, it is desirable to select appropriately according to the application and required physical properties, and it is not an example to limit, but polyethylene terephthalate, polypropylene, nylon, etc. are easy to use in cost for packaging of medical supplies, drugs, foods, etc. It is desirable to use a substrate having high gas barrier properties such as polyethylene naphthalate, polyimides, and polyethersulfone for packaging that protects contents that extremely dislike moisture, such as electronic members and optical members.
[0023]
The thickness of the plastic film substrate is not limited, but it is easy to use one having a thickness in the range of 6 μm to 200 μm depending on the application.
[0024]
Next, the hydroxyl group-containing polymer (A) used in the present invention is preferably any of polyvinyl alcohol, starch, and cellulose. However, in consideration of using a coating method in forming a layer, polyvinyl alcohol is preferably used. Alcohol or starch is easy to turn into solution and easy to use. In the case of using cellulose, it is preferable to use a fine powder which is dispersed in a coating solution or which is partially or entirely converted into carboxymethyl cellulose by chemical modification.
[0025]
Next, polyacrylic acid or polymethacrylic acid as at least one or more components (B) selected from polyacrylic acid or a partially neutralized product thereof, polymethacrylic acid or a partially neutralized product thereof used in the present invention These are polymers obtained by polymerizing polyacrylic acid and polymethacrylic acid, respectively. A usual radical polymerization method can be used for the polymerization, and particularly, solution polymerization is easy to use because the polymer is obtained as a solution. However, if it is desired to obtain a polymer having a higher molecular weight in terms of use and physical properties, it is preferable to employ a suspension polymerization method or a bulk polymerization method. Further, it can also be obtained by hydrolyzing a polyacrylic ester or a polymethacrylic ester. Further, it can be obtained by reacting these with an alkali metal or an alkaline earth metal alone or a hydroxide thereof. In addition, these production methods are not limited examples, and can be used because they are commercially available. Further, the degree of neutralization is preferably 30% (mol ratio) or less, more preferably 20% or less.
[0026]
Next, the ceramic vapor deposition layer 4 is provided to impart gas barrier properties, and is made of aluminum oxide, silicon oxide, magnesium oxide, or titanium oxide in consideration of ease of handling, economy, gas barrier performance, and the like. It is preferable to have at least one or more types as components. Further, these metal oxides do not necessarily have to be oxidized and saturated. Further, various additives may be mixed according to required physical properties. The composition ratio, the degree of oxidation, and the additives of these ceramics may be set in consideration of the use, cost, characteristics of the film forming apparatus, and the like.
[0027]
Examples of the film forming means include known methods such as a vacuum deposition method, a sputtering method, and a chemical vapor deposition method (CVD method), and an electron beam heating type vacuum deposition method is particularly effective. It is not limited.
[0028]
The thickness is not limited, but is preferably 1 nm or more and 100 nm or less. If the thickness is smaller than this, it is difficult to uniformly form a film, so that gas barrier performance is hardly exhibited. If the thickness is more than this, gas barrier performance is exhibited, but the flexibility decreases. Poor processability and practicality, and uneconomical.
[0029]
Next, the plasma processing will be described. In the first place, this treatment is performed mainly for the purpose of improving the adhesion between the plastic film substrate and the ceramic vapor deposition layer. Here, the low-temperature plasma is preferably a reactive ion etching mode discharge using at least one of argon, nitrogen, and oxygen as a plasma gas.
[0030]
In the reactive ion etching mode, the electrode is formed in a shape like a hollow box, and the electrode is made larger with respect to the counter electrode (here, it is equivalent to a drum for a base film receiving and winding type). , Which anodizes the life electrode, and can obtain a higher bias value than an ordinary plasma generator. The actual device is not particularly limited to this description as long as it follows the basic principle. Further, similar plasma processing can be performed by placing a base material on the cathode side even in a normal plasma generator.
[0031]
The processing conditions indicated by the processing speed, the energy level, and the like should be appropriately set according to the type of the base material, the application, the characteristics of the discharge device, and the like. However, it is necessary that the bias value of the plasma is 100 [V] or more and the above-mentioned Eb value is 200 [V · s · m ⁻² ] or more. Even if the value is slightly lower than this, a certain degree of adhesion is exhibited. However, the advantage is lower than the untreated product.
[0032]
Regarding the plasma gas and its mixing ratio, the flow rate differs between the introduced and effective components depending on the pump performance and the mounting position, etc., and should be appropriately set according to the application, substrate, and device characteristics. It should be noted that the moisture content and the amount of gas contained in the base material used affect the degree of vacuum in this step and the later-described ceramic vapor deposition step.
[0033]
If necessary, a composite coating 5 having a hydrolyzate of polyvinyl alcohol and a metal alkoxide as a component can be provided on the ceramic vapor deposition layer. The composite coating is provided for the purpose of improving gas barrier properties, protecting the deposited layer, improving printability, and the like.
The polyvinyl alcohol referred to here is generally a polymer obtained by hydrolyzing polyvinyl acetate obtained by polymerizing vinyl acetate, but the production method is not limited. In addition, it can be chemically modified to impart various physical properties, and does not depart from the gist of the present invention.
[0034]
There are various types of metal alkoxides, and silicon alkoxides are preferable in consideration of handling properties and costs. In addition, if there is a demand for improving the flexibility and adhesion of the film, it is preferable to appropriately select and add a so-called silane coupling agent without being limited to tetraalkoxide.
[0035]
The method for forming the above-mentioned composite film is not particularly limited, but a known coating method such as a dipping method, a roll coating method, a screen printing method, and a spray method can be used.
[0036]
When the gas barrier film of the present invention is used as a package such as a packaging bag, it is necessary to use the gas barrier film in combination with a heat seal layer as an adhesive layer.
[0037]
As the heat seal layer, a known polymer film such as polypropylene, polyethylene, and polyethylene-co-vinyl acetate can be used, and is not limited. Further, a heat seal varnish or a hot melt material may be used. Alternatively, the substrate itself may have heat sealing properties.
[0038]
Regarding the lamination method, a known method such as a dry lamination method, a wet lamination method, an extruder method, and a coating method can be used, and an appropriate means may be selected according to a material or the like, and the method is not limited thereto. Not something.
In this case, the lamination structure may be appropriately determined according to the application.
[0039]
【Example】
Hereinafter, one embodiment of the present invention will be specifically described.
[0040]
On one side of a 12 μm thick 500 mm wide polyethylene terephthalate (PET) film, a partially neutralized product of sodium hydroxide of polyacrylic acid (molecular weight (GPC, PS conversion) = about 10,000) (neutralization degree: 10%) and polyvinyl alcohol An aqueous solution containing (Kuraray's “Poval PVA124”) as a main component was applied by a gravure coating method, dried in an oven, and then additionally dried by a hot roll to form a coating (a layer).
[0041]
Next, a plasma processing layer having an input of 120 W and a bias of 444 V (Eb = 888 [Vsm- ² ]) was provided by a reactive ion etching mode plasma processing apparatus (layer b).
An aluminum oxide (unsaturated oxide) layer was provided on the layer b by a vacuum evaporation method using an electron beam heating method (layer c).
[0042]
Further, an aqueous solution mainly containing hydrochloric acid hydrolyzate of tetraethoxysilane and polyvinyl alcohol (“Poval PVA124” manufactured by Kuraray) is applied by a gravure coating method, dried in an oven, and then added by a hot roll. The coating was provided by drying (layer d).
[0043]
Further, a biaxially stretched nylon ("Emblem ONMB-RT" manufactured by Unitika Ltd., thickness 15 .mu.) As a heat seal layer is bonded to the d layer side of the film by a dry lamination method using a urethane-based adhesive. The surface and unstretched polypropylene (“RXC-18” manufactured by TOCELLO, thickness: 70 μm) were similarly bonded by a dry lamination method using a urethane-based adhesive.
[0044]
Depending on the presence or absence of the a, b, c, and d layers of the laminated film obtained above, the gas barrier film of the present invention has Examples 1 to 5, and the comparative examples have Comparative Examples 1 to 5, The layer structure is shown in Table 1. The laminated film obtained above was formed into an A5-sized four-way pouch, filled with 150 ml of tap water, and then subjected to a hot water recovery type retort treatment at 121 ° C. for 30 minutes. Table 1 shows the results of evaluating the oxygen permeability and water vapor permeability before and after the retort based on the following evaluation methods. For the b layer, “RIE” indicates that the reactive ion etching mode plasma processing was performed, and “general” indicates that the input was 1200 W-bias-25 V (Eb = −50 [V · S · m ^-2 ]).
[0045]
As the base material, biaxially stretched nylon (“Emblem ON” manufactured by Unitika, thickness 15 μ) was used in place of the PET film, and layers a, b, c, and d were provided in the same manner as described above. A, b of a laminated film obtained by bonding a linear low-density polyethylene (“TUX FC-S” manufactured by Tamapoly, thickness: 60 μm) as a heat seal layer by a dry lamination method using a urethane adhesive. , C, and d according to the presence or absence of the layers, the gas barrier film of the present invention has Examples 6 to 10, the comparative examples are Comparative Examples 6 to 10, and the layer configurations are shown in Table 2. . The laminated film obtained above was formed into an A5-sized four-way pouch, filled with 150 ml of tap water, and then boiled at 95 ° C. for 30 minutes. Table 2 shows the results of evaluating the oxygen permeability and water vapor permeability before and after the boil based on the following evaluation methods. For the b layer, “RIE” indicates that the reactive ion etching mode plasma processing was performed, and “general” indicates that the input was 1200 W-bias-25 V (Eb = −50 [V · S · m ^-2 ]).
[0046]
(Evaluation of gas barrier properties)
・ Oxygen permeability measurement (Measurement device: OXTRAN 2/20 measurement condition, manufactured by Modern Control Co .: 30 ° C.-70% RH)
-Water vapor permeability measurement (Measurement device: PERMATRAN 3/31 manufactured by Modern Control Co., Ltd. Measurement conditions: 40 ° C-90% RH)
[0047]
[Table 1]

[0048]
[Table 2]

[0049]
It is clear from Tables 1 and 2 that the gas barrier films of the present invention (Examples 1 to 10) all maintain high barrier properties even after retort treatment or boil treatment. On the other hand, in Comparative Examples 1 and 2, although the water vapor barrier property was maintained to a certain level, the oxygen barrier property was significantly reduced. Comparative Example 4 retains the oxygen barrier property, but has a water vapor barrier equivalent to that of the substrate (Comparative Example 5). The result is almost the same in the case of the nylon base material.
[0050]
【The invention's effect】
According to the present invention, there is provided a gas barrier film capable of maintaining a high level of oxygen barrier properties and water vapor barrier properties even through severe processing steps such as retort processing and boil processing, and a package using the same. be able to.
Therefore, it is suitably used as a packaging film and a package in the packaging field of foods, pharmaceuticals, electronic members, electronic devices, and the like in which the contents need to be prevented from being deteriorated or deteriorated by oxygen, water vapor, or the like.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of a configuration of a gas barrier film of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gas barrier film 2 ... Plastic film base layer 3 ... Layer consisting of a hydroxyl group-containing polymer (A) and component (B) 4 ... Ceramic deposition layer 5 ... Composite coating

Claims (12)

On one surface of a plastic film substrate, a hydroxyl group-containing polymer (A) and at least one or more components (B) selected from polyacrylic acid or a partially neutralized product thereof, polymethacrylic acid or a partially neutralized product thereof, A gas barrier film, comprising: a layer made of, and a ceramic vapor deposition layer provided on the other side. The plastic film substrate has at least one of polyolefin, polyester, polyamide, polyimide, cellulose, acrylic resin, polyethersulfone, polylactic acid, and polyvinyl alcohol as a component and / or a copolymer component. Item 7. The gas barrier film according to Item 1. The gas barrier film according to claim 1, wherein the hydroxyl group-containing polymer has at least one of polyvinyl alcohol, starch, and cellulose as a component and / or a copolymer component. The partially neutralized product of polyacrylic acid or the partially neutralized product of polymethacrylic acid is an alkali metal salt and / or an alkaline earth metal salt, 4. Gas barrier film. The gas barrier film according to any one of claims 1 to 4, wherein the ceramic deposition layer is made of any one of aluminum oxide, silicon oxide, and magnesium oxide, or a mixture thereof. The gas barrier film according to any one of claims 1 to 5, wherein a surface of the plastic film substrate on which the ceramic vapor deposition layer is laminated is subjected to a plasma treatment. The plasma treatment uses at least one of argon, nitrogen, and oxygen as a plasma gas type, sets a plasma bias value to 100 V or more, and is defined by Eb = bias value / (film width × processing speed). 7. The gas barrier film according to claim 6, wherein the low-temperature plasma treatment is performed at a low Eb value of 200 [Vsm- ² ] or more. The gas barrier film according to claim 6, wherein the plasma processing is a reactive ion etching mode plasma processing. The gas barrier film according to any one of claims 1 to 8, wherein the plasma treatment or the ceramic deposition is performed in an in-line process. The gas barrier film according to any one of claims 1 to 9, wherein a composite coating having a hydrolyzate of polyvinyl alcohol and a metal alkoxide as a component is provided on the ceramic vapor deposition layer. The gas barrier film according to claim 10, wherein the metal alkoxide is a silane alkoxide and / or a silane coupling agent. A gas barrier package formed by using the gas barrier film according to any one of claims 1 to 11.

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