JP3563788B2 - Lid material - Google Patents

Description

但し、充填前後の水蒸気透過度、及び酸素透過度は、充填テスト前のものは、ふた材のフィルムで測定し、充填後のふた材は、１００ｍｍ×１００ｍｍの大きさの容器で測定した値を１００倍し、アルミニゥム成形容器の水蒸気透過度、及び酸素透過度は０としてｍ^２ 換算して記載した。
接着強度を測定したときの剥離部は、いずれも酸化珪素層と接着性樹脂層又は易剥離ヒートシール樹脂層との間で剥離した。
【００２９】
【発明の効果】
以上記載したように、本発明のバリア層であるＳｉＯｘ層の厚さは、６０〜３００Åで透明性もよく、柔軟性に富み、そして、酸素透過度は、１ ｃｃ ／ｍ^２・２４ｈ以下、水蒸気透過度は、１ ｇ／ｍ^２・２４ｈ以下である。
該ＳｉＯｘ層には、炭素、水素、珪素及び酸素のなかの１種、あるいは２種以上の元素からなる化合物は、酸化珪素の層が炭素系高分子化合物に類似した物性をもたせる作用をもつものである。したがって、ＳｉＯｘ層は延展性に富み、ＳｉＯｘとフィルムとの接着強度も高く、ヒートシール時の屈曲にもバリア性の低下も少なく安定したバリア性を維持できた。また、廃棄、焼却する時に塩素による環境汚染もなく、焼却後の灰分も少なく、処理も容易なものである。
【図面の簡単な説明】
【図１】本発明のふた材の基本の積層構成を示す断面概略図である。
【図２】本発明のふた材の他の積層構成を示す断面概略図である。
【図３】補強フィルムを設けた本発明のふた材の積層構成を示す断面概略図である。
【図４】本発明のふた材の実施例の積層構成を示す断面概略図である。
【図５】本発明のふた材の他の実施例の積層構成を示す断面概略図である。
【符号の説明】
１ 基材フィルム
１１ ポリエステルフィルム
２ ＳｉＯｘ層
２１ ＳｉＯｘフィルム
３ 補強フィルム
３１ 延伸ポリプロピレンフィルム
４ 接着剤層
５ プライマー層
６ 接着用樹脂層
６１ ポリエチレン
７６ 易剥離ヒートシール樹脂層（コーティング）
７７ 易剥離ヒートシール樹脂層（フィルム）
９ 絵柄層[0001]
[Industrial applications]
The present invention relates to a lid material for a molded container, and more particularly, to a lid material for a molded container that is filled with dairy products such as coffee milk, syrup, and yogurt, and foods such as fruit juice, jelly, and cup ramen.
[0002]
[Prior art]
A conventional molded container filled with the contents and sealed is subjected to a chemical effect due to a synergistic effect with the barrier property of the lid material until the end consumer opens the container through the logistics process. It is required to prevent contamination and deterioration due to physical and physical changes.
The molded container is formed of a metal having a laminated plastic layer, a relatively thick plastic, a multi-layer plastic, or the like, and has the characteristics of the container necessary for storing the contents. On the other hand, the lid material is generally a filling machine that seals by heat sealing. If the lid material is thick, the thermal conductivity is reduced and the sealing property may be impaired, so a film of 50 to 150 μm is applied, and a barrier property is provided. For this purpose, a laminated film of a plastic film and an aluminum foil, an aluminum vapor-deposited film, a polyvinylidene chloride coated film or a saponified ethylene / vinyl acetate copolymer film has been used.
[0003]
In recent years, the method of treating used food containers has become a major social problem. From the perspective of effective use of resources, petrochemical plastics are converted to fuel by incineration, and incombustibles are compressed and transported for recycling or landfill. Had been made.
[0004]
However, the conventional lid material using an aluminum foil as a barrier layer has a problem that the effect of promoting sales is poor because the contents cannot be seen. On the other hand, in order to make the contents visible, there is a relatively barrier property except for the opaque aluminum foil, and the use of a stretched polyester or stretched nylon film or polycarbonate has an effect as a barrier layer of a specific content. However, it was not always satisfactory in terms of the oxygen barrier.
[0005]
Further, a technique for a lid material of a molded container using a plastic film provided with a vapor-deposited metal oxide having excellent oxygen barrier properties as a barrier layer has also been disclosed. However, a vapor deposition layer obtained by a conventional physical vapor deposition method requires a relatively thick vapor deposition layer to provide a barrier property. Therefore, when the vapor deposition layer is not colorless and transparent, the color of the contents is changed, or the laminated film having the metal oxide vapor deposition layer with small extensibility and the molded container are heat-sealed when the heat sealing is performed. There is a problem that the vapor deposition layer cannot follow the expansion and contraction of the film, particularly when the film is extended, and causes cracks.
[0006]
Laminated films including a barrier layer composed of a polyvinylidene chloride coated film and a saponified ethylene / vinyl acetate copolymer film have also been used.
However, since the polyvinylidene chloride coated film contains chlorine, it has a problem that chlorine gas or hydrogen chloride gas is generated when disposed and incinerated after use, which is not preferable from the viewpoint of corrosion of an incinerator and environmental hygiene.
On the other hand, the saponified ethylene / vinyl acetate copolymer has the advantage of not only low oxygen permeability but also excellent barrier properties of flavor components, but has a drawback that gas barrier properties are reduced under high humidity. For this purpose, a moisture-proof film is laminated on both sides of a saponified ethylene-vinyl acetate copolymer film that is a barrier layer, but avoid moisture absorption from the edge of the film during long-term storage. Was not possible.
[0007]
[Problems to be solved by the invention]
The biggest problem with incineration or recycling of waste is that it is composed of raw materials that are not suitable for any of the treatments. For example, in a laminated film composed of an aluminum foil and a plastic film, there is a problem in treating metal aluminum that remains as an incombustible substance when incinerated. Conversely, plastics contained in those treated with incombustibles are effective combustion aids when used for incineration, but they become waste that is landfilled because they exist in incombustibles. There was a problem of resource waste.
Of course, some attempts have been made to industrially separate these constituent materials and recycle them as raw materials, but the reality is that the technology has not yet been completed.
The present invention provides a base film with a very thin layer of silicon oxide having high flexibility and extensibility so that a used lid material can be used as a combustion aid when incinerating refuse, and an aluminum foil or the like can be used. The purpose is to supply a lid material having a chlorine-free barrier property.
[0008]
[Means for Solving the Problems]
To achieve the above object, the lid material of the present invention has a barrier layer provided on at least one surface of a base film by a plasma enhanced chemical vapor deposition method, and the barrier layer is made of silicon oxide and carbon, hydrogen, A continuous layer containing a compound composed of one or more elements from silicon and oxygen (hereinafter, an SiOx layer, and a film on which SiOx is applied will be referred to as an SiOx film).
The distribution of the compound composed of one or more of carbon, hydrogen, silicon and oxygen contained in the SiOx layer decreases from the surface of the barrier layer toward the interface of the base film. Things.
Further, the lid member is formed of a laminated film of an easily peelable heat seal resin layer and a base film having a SiOx layer.
[0009]
The lid material of the present invention is an SiOx film 21 in which a SiOx layer 2 is provided on a base film 1 as shown in FIG. Further, the easily peelable heat seal resin layer 76 is provided on the SiOx layer 2 by melt extrusion coating.
As shown in FIG. 2, the SiOx layer 2 and the film-like easily peelable heat seal resin layer 77 can be laminated by a primer layer 5 and an adhesive resin layer 6 provided as necessary.
[0010]
Further, as shown in FIG. 3, the reinforcing film 3 and the SiOx layer 2 of the SiOx film 21 are laminated with the adhesive layer 4, and an exfoliation heat seal resin layer 76 is melt-extruded on the other surface of the SiOx film. It can also be provided by coating.
[0011]
As shown in FIG. 4, a picture layer 9 is provided on the SiOx layer 2 of the SiOx film 21, and if necessary, the primer layer 5 and the easily peelable heat sealing resin layer 77 are laminated via the polyethylene 61 which is an adhesive resin layer. Thus, a lid member provided with a picture layer can be formed.
[0012]
Further, as shown in FIG. 5, after the pattern layer 9 provided on the stretched polypropylene film 31 as the reinforcing film and the SiOx film 21 are laminated via the adhesive layer 4, the easily peelable heat seal resin layer 76 is melt-extruded. There is a configuration method such as providing by coating.
[0013]
As the substrate film on which the SiOx layer is provided, a stretched or unstretched film of polyester, nylon, polypropylene, or the like having flexibility can be used. However, preferably, the film can be formed with a relatively small thickness with high accuracy, and the transparency is excellent. It is a stretched film of polyester.
Organic silicon compounds used for forming the SiOx layer include 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinylmethyldisiloxane, methyltrimethoxysilane, hexamethyldisilane, methylsilane, dimethylsilane, and trimethyl. Select from silane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane, etc. And preferably 1,1,3,3-tetramethyldisiloxane and hexamethyldisiloxane.
[0014]
The above organic silicon compound, which is a liquid, is vaporized, and a raw material gas obtained by mixing oxygen gas and helium and / or argon as an inert gas is introduced into a plasma chemical vapor deposition machine provided with a film provided with SiOx. Thus, a SiOx layer of 60 to 300 ° is formed.
The vapor deposition layer formed by the plasma chemical vapor deposition method can be made colorless and transparent and have a barrier property by reducing the thickness of the layer as compared with the conventional physical vapor deposition method.
The SiOx layer thus formed contains a compound composed of one or more of carbon, hydrogen, silicon and oxygen.
Specifically, there is a hydrocarbon having an alkyl group such as a methyl group, or a derivative having a hydroxyl group such as a silyl group or a hydrosilica containing a silylene group or a silanol.
Other than the above, the type and amount of the compound contained in the barrier layer can be controlled by changing the composition of the source gas and the deposition conditions.
[0015]
The content of these compounds is 0.1 to 40% by weight, preferably 5 to 20% by weight of the SiOx layer. When the content is less than 0.1% by weight, the impact resistance and spreadability of the barrier layer become insufficient, cracks are generated due to bending or the like, and high barrier properties cannot be maintained. On the other hand, if it exceeds 40% by weight, the barrier properties are undesirably reduced.
In addition, the concentration of the compound composed of one or more of the above-mentioned carbon, hydrogen, silicon and oxygen contained in the SiOx layer is low in a portion close to the base film, and low in a surface layer portion of the vapor deposition. It is configured to have a high concentration.
[0016]
The reinforcing film is a layer provided to provide the strength and rigidity of the lid material and the cushioning properties of the lid material, and usually serves as a printing substrate on which a picture layer is provided. For example, uniaxial or biaxially stretched films such as polyester, polypropylene, polycarbonate, polyamide, cellulose triacetate, cellulose diacetate, and rigid vinyl chloride film can be used.
The pattern layer is formed by printing with a rotary printing machine such as gravure printing or flexographic printing using a normal printing ink having post-processing suitability such as the film and the lamination.
[0017]
In some cases, a soft plastic film having a cushion effect to ensure the sealing of the lid material is used as a reinforcing film or an adhesive resin layer.
Although polyethylene 61 shown in FIG. 4 has the same effect, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, unstretched ionomer In addition to the film, these foamed films can be used.
[0018]
When the thickness and strength are not required for the lid material, a lid material of the base film shown in FIG. 1 from which the reinforcing film is omitted and the easily peelable heat sealing resin layer can be formed. When this reinforcing film is omitted, it is preferable that a picture layer is provided on the SiOx layer to form a laminated film in which the SiOx layer and the picture layer are inserted and protected.
[0019]
The easily peelable heat seal resin layer is made of thermoplastic resin such as polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic ester copolymer, polyisobutylene rubber, styrene / butadiene rubber, acrylic An appropriate amount of a rosin, a hydrogenated rosin, an ester gum, a polyterpene, a petroleum resin or the like is added as a tackifier to a mixture of resins such as resin, polyamide, polyester and polyurethane.
Furthermore, if necessary, an oligomer of the above resin, a low-melting hydrocarbon, a filler for preventing blocking, a lubricant, an antioxidant, or the like, which is a softener, may be added.
[0020]
The easily peelable heat-sealing resin layer is formed by applying a material having a high melting point and a high hot-melt viscosity by melt extrusion coating or hot lacquer coating applied by heating and dissolving in an organic solvent. A hot-melt type having a low hot-melt viscosity can be provided by hot-melt coating.
[0021]
The easily peelable heat seal resin layer can be provided by directly coating the SiOx film or the reinforcing film, but can also be formed by providing a primer layer and a polyethylene layer and further coating.
In addition, the easily peelable heat seal resin layer formed into a film in advance can be laminated as an adhesive or a primer layer and an adhesive resin layer via, for example, polyethylene.
[0022]
The lamination of the reinforcing film and the SiOx film according to claim 2 can be formed by dry lamination using a normal adhesive layer or sandwich lamination using a molten polyolefin.
[0023]
[Action]
The SiOx layer of the SiOx film formed as described above is formed by a plasma chemical vapor deposition method using a source gas composed of a vapor of an organic silicon compound, oxygen and an inert gas. Therefore, the thickness thereof is sufficient to have a barrier property of 60 to 300 °, good transparency, a dense continuous layer, high flexibility, and an oxygen permeability of 1 cc / m ² · 24 h or less. water vapor transmission rate is less than 1 ^{g /} m 2 · 24h.
In the SiOx layer, a compound composed of one or more of carbon, hydrogen, silicon and oxygen is added to an organic polymer compound mainly containing carbon, hydrogen and oxygen in a silicon oxide layer. It has the function of giving similar physical properties. Therefore, the SiOx layer is rich in spreadability, has a high adhesive strength between the SiOx film and the film, and acts to prevent cracking when the SiOx film is laminated with another film.
The lid material provided with the easily peelable heat seal resin layer has excellent oxygen barrier properties, has no cracks in the heat seal portion, and has an excellent effect in protecting the contents.
[0024]
【Example】
Examples will be described with reference to the drawings,
[Example 1]
As shown in FIG. 4, hexamethyldisiloxane is vaporized into polyester film 12 having a thickness of 12 μm as a base film, and a mixed gas consisting of hexamethyldisiloxane: oxygen gas: helium gas = 1: 9: 8 is formed. As a raw material gas, vapor deposition was performed on a polyester film 11 having a thickness of 12 μm to form an SiOx film 21 shown in FIG.
Next, a pattern layer 9 is provided on the SiOx layer 2 of the SiOx film 21 by gravure rotary printing with a polyester-based ink, and further, a polyurethane-based primer 5 applied to the pattern layer 9 by a melt extrusion coater, and an adhesive resin layer. FIG. 4 shows a sandwich lamination of a 30 μm-thick easily peelable heat seal resin layer film 77 (manufactured by Dainippon Resin Co., Ltd .: polyolefin-based easily peelable heat seal resin EP2) via a 20 μm thick low-density polyethylene 61. The soft lid material for a molded container shown in (1) was constructed.
[0025]
[Example 2]
As shown in FIG. 5, a pattern layer 9 is provided on the treated surface of a stretched polypropylene film 31 having a thickness of 40 μm as a reinforcing film by gravure rotary printing with a polyester-based ink, and a polyester-isocyanate-based adhesive layer 4 provided on the pattern layer is provided. The SiOx layer 21 of the SiOx film 21 prepared in Example 1 was in contact with and laminated on the polyester film layer 11 with a heating roll coater, and the easily peelable heat seal resin layer 76 (Dainippon Ink and Chemicals Co., Ltd.) Manufacture: Hot melt coating material for heat sealing (Dick melt DX47B) was applied at 10 μm to form a hard lid material for a molded container shown in FIG.
[0026]
(Comparative example)
On one side of a 12 μm polyester film 11, silicon oxide 2 was provided in a thickness of 800 ° by a conventional vapor deposition method, and then the pattern layer 9 was formed on the silicon oxide layer 2 of the film by gravure rotary printing with a polyester-based ink. Further, a polyurethane-based primer layer 5 and a low-density polyethylene 61 as an adhesive resin layer are applied to the pattern layer 9 through a 20 μm film 20 of a 30 μm-thick easily peelable heat seal resin layer film 77 ( A soft lid material for a molded container having the same configuration as that of Example 1 shown in FIG. 4 except that a polyolefin-based easily peelable heat seal resin EP2) manufactured by Dainippon Resin Co., Ltd. Was configured.
[0027]
The lid material constituted in the example and the comparative example was heat-sealed with a flange portion of an aluminum molded container having a flange width of 6 mm and an outer diameter of 80 mm in which a polypropylene film was laminated on the inner surface, and a sealed container per molded container was sealed. Changes in oxygen permeability and water vapor permeability were measured by the following methods.
(Test method)
-Oxygen permeability is measured by OXTRAN manufactured by MOCON under conditions of a temperature of 23 ° C and a humidity of 90% RH.
-The water vapor permeability is measured by PERMATRAN manufactured by MOCON under conditions of a temperature of 40 ° C and a humidity of 90% RH.
-Adhesion strength was measured by heat-sealing the sample between the easily peelable heat-sealing resin layers, measuring the adhesion, confirming the peeled portion, and measuring the peel strength according to JIS K7128.
[0028]
Table 1 shows the results of the evaluation.
[Table 1]

However, the water vapor permeability before and after filling, and the oxygen permeability before the filling test were measured with a lid material film, and the filled lid material was measured with a container measuring 100 mm x 100 mm. multiplied by 100, Aruminiumu water vapor permeability of the molded container, and the oxygen permeability was described m ² calculated as 0.
When the adhesive strength was measured, the peeled portions were peeled between the silicon oxide layer and the adhesive resin layer or the easily peelable heat seal resin layer.
[0029]
【The invention's effect】
As described above, the thickness of the SiOx layer is a barrier layer of the present invention may be transparent in 60～300A, highly flexible, and the oxygen permeability, 1 cc ^/ m 2 · 24h or less, water vapor permeability is less 1 ^{g /} m 2 · 24h.
In the SiOx layer, a compound composed of one or more of carbon, hydrogen, silicon and oxygen has an effect that the silicon oxide layer has properties similar to a carbon-based polymer compound. It is. Therefore, the SiOx layer was rich in extensibility, the adhesive strength between the SiOx and the film was high, and there was little bending or deterioration in barrier properties during heat sealing, and stable barrier properties could be maintained. In addition, there is no environmental pollution due to chlorine at the time of disposal and incineration, the ash content after incineration is small, and the treatment is easy.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a basic laminated structure of a lid member of the present invention.
FIG. 2 is a schematic cross-sectional view showing another laminated structure of the lid member of the present invention.
FIG. 3 is a schematic sectional view showing a laminated structure of a lid member of the present invention provided with a reinforcing film.
FIG. 4 is a schematic sectional view showing a laminated structure of an embodiment of a lid member of the present invention.
FIG. 5 is a schematic sectional view showing a laminated structure of another embodiment of the lid member of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 base film 11 polyester film 2 SiOx layer 21 SiOx film 3 reinforcing film 31 stretched polypropylene film 4 adhesive layer 5 primer layer 6 bonding resin layer 61 polyethylene 76 easily peelable heat seal resin layer (coating)
77 Easy peel heat seal resin layer (film)
9 Picture layer

Claims (2)

A barrier layer provided on at least one surface of the base film by a plasma-enhanced chemical vapor deposition method, and the barrier layer further vaporizes an organosilicon compound, and is mixed with oxygen, an inert gas and a raw material. Using a gas, formed by a plasma-enhanced chemical vapor deposition method, a continuous layer containing a compound composed of one or more elements from silicon oxide and carbon, hydrogen and oxygen, further comprising the compound Has a structure in which the content is 0.1 to 40% by weight of the continuous layer and decreases from the surface of the continuous layer toward the interface with the base film. _X A film, and further comprising the SiO _X A lid material comprising an easily peelable heat seal resin layer laminated on a surface of a barrier layer constituting a film. A barrier layer provided on at least one surface of the base film by a plasma-enhanced chemical vapor deposition method, and the barrier layer further vaporizes an organosilicon compound, and is mixed with oxygen, an inert gas and a raw material. Using a gas, formed by a plasma-enhanced chemical vapor deposition method, a continuous layer containing a compound composed of one or more elements from silicon oxide and carbon, hydrogen and oxygen, further comprising the compound Has a structure in which the content is 0.1 to 40% by weight of the continuous layer and decreases from the surface of the continuous layer toward the interface with the base film. _X A film, and further comprising the SiO _X A lid material comprising a reinforcing film laminated on a surface of a barrier layer constituting a film, and an easily peelable heat-sealing resin layer laminated on a surface of the base film.

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