JPS5925644Y2 - Heat-sealing lid material for food and drink containers - Google Patents

Description

【考案の詳細な説明】 本考案は、合成樹脂製のビン等の口部に加熱により密着
熱封緘される熱封緘蓋材の改良に関する。[Detailed Description of the Invention] The present invention relates to an improvement in a heat-sealing lid material that is tightly heat-sealed to the opening of a synthetic resin bottle or the like by heating.

従来、各種飲食品包装において汎用されているアルミニ
ウム箔を基材とする熱封緘蓋材の構造は、アルミニウム
箔・ポリエチレンフィルム・ホットメルト接着剤の積層
構造より成るが、この種の蓋材に於いては、近時蓋るし
く発展しつつある高速熱封緘技術への適合性並びに食品
衛生等の点で次のような重大な困難が生起されている。Conventionally, the structure of heat-sealing lids based on aluminum foil, which has been widely used in various food and beverage packaging, consists of a laminated structure of aluminum foil, polyethylene film, and hot melt adhesive. However, the following serious difficulties have arisen in terms of compatibility with high-speed heat sealing technology, which has been rapidly developing in recent years, and food hygiene.

即ち、最近の高速熱封緘機による封緘速度は毎時約２０
０００本にも達し、これに従来蓋材を適用した場合、ワ
ックス含有ホットメルト接着剤の所謂ホットタック性の
不足、蓋材表面の滑性が不充分であること等により、作
業上の各種障害の生起が回避され難い。That is, the sealing speed of recent high-speed heat sealing machines is approximately 20 per hour.
If conventional lidding materials were applied to these, various problems occurred due to the lack of so-called hot tack properties of wax-containing hot melt adhesives, insufficient lubricity of the lidding material surface, etc. It is difficult to avoid the occurrence of

更に、ワックスを主成分として含有するホットメルト接
着剤層自体、塗膜堅牢性に欠けるものであるため、プレ
ス打抜き時にそれが刃先に耐着集積し、飲食物容器内に
落下してしまう等の問題も生ずる。Furthermore, the hot-melt adhesive layer itself, which contains wax as its main component, lacks coating film fastness, so it tends to accumulate on the cutting edge during press punching and may fall into food and drink containers. Problems also arise.

他方、食品包装材に関する食品衛生基準は近時盤々厳格
化されつつあり （例えば、ポリオレフィン等衛生協議
会規定のノルマルへブタン溶出試験、等）、飲食物との
接触部分に多量のワックス成分を有する従来蓋材による
限りこれらの基準は到底達成され得ない。On the other hand, food hygiene standards for food packaging materials have been becoming increasingly strict in recent years (e.g. normal hemobutane elution test stipulated by the Polyolefin Sanitation Council, etc.), and large amounts of wax components are being applied to areas that come into contact with food and drink. These standards cannot be achieved by conventional lid materials.

従って、本考案の目的は、飲食物との接触部分に食品衛
生上好ましくないワックス等の成分を全く含有せず、高
速度熱封緘機への適合性並びに積層量強度等の蓋材とし
ての適性が格段に向上された熱封緘蓋材の改良構造を提
供することにある。Therefore, the purpose of the present invention is to create a material that does not contain any components such as wax that are undesirable from a food hygiene perspective in the parts that come into contact with food and drink, is suitable for high-speed heat sealing machines, and is suitable as a lid material in terms of lamination strength and other properties. An object of the present invention is to provide an improved structure of a heat-sealing lid material with significantly improved properties.

添附図面を参照して、本考案蓋材は、アルミニウム箔１
の片面上に、ポリエチレン、ポリプロピレン等のポリオ
レフィン、ポリビニルアルコール、サーリンＡ（商品名
）等のアイオノマ及びポリエチレンエチルアクリレート
、ポリエチレンアクリル酸等のエチレン共重合樹脂又は
それらの部分けん化樹脂などのエチレン共重合体系樹脂
より選択される１種以上の樹脂材より成る中間樹脂層２
、及びメルトインデックス（ＭＩ）が２〜４０であり且
つ酢酸ビニル含有量が５〜３０％であるエチレン・酢酸
ビニル共重合樹脂層（以下ＥＶＡ樹脂層と略称する）３
を、溶融押出積層法、熱圧着又は接着剤による貼合等の
手段で一体的に積層形威し、次いで通常、このようにし
て形成された積層材に、以下に詳述する微細凹凸模様４
を更に型付加工して構成される。Referring to the attached drawings, the lid material of the present invention includes aluminum foil 1
On one side, polyolefins such as polyethylene and polypropylene, polyvinyl alcohol, ionomers such as Surlyn A (trade name), and ethylene copolymer systems such as polyethylene ethyl acrylate, ethylene copolymer resins such as polyethylene acrylic acid, or partially saponified resins thereof. Intermediate resin layer 2 made of one or more resin materials selected from resins
, and an ethylene/vinyl acetate copolymer resin layer (hereinafter abbreviated as EVA resin layer) 3 having a melt index (MI) of 2 to 40 and a vinyl acetate content of 5 to 30%.
are integrally laminated by means such as melt extrusion lamination, thermocompression bonding, or bonding with an adhesive, and then the laminate thus formed is usually provided with a fine uneven pattern 4 as detailed below.
It is constructed by further molding.

上記積層材構造に於いて、ＥＶＡ樹脂層３は、熱封緘材
層として機能するものであり、特にホラＩ・タック性に
優れているため高速熱封緘に好適である。In the above-mentioned laminated material structure, the EVA resin layer 3 functions as a heat sealing material layer, and is particularly suitable for high-speed heat sealing because it is excellent in roll I and tack properties.

加えて、同層は化学的安定性、耐寒性及びフィルム強度
等の点でも充分な特性を有し、飲食物容器の封緘素材と
して適切なものと云い得る。In addition, the same layer has sufficient properties in terms of chemical stability, cold resistance, film strength, etc., and can be said to be suitable as a sealing material for food and drink containers.

尚、ＥＶＡ樹脂層３の形成樹脂材の前記特定は、下記に
示す通りその成膜性、ブロッキング性、耐食耐候性等を
検討した結果なされたものであり、所要の場合、これら
は食品衛生上問題のない微量のすべり剤（例えば脂肪酸
アミド）、酸化防止剤（例えばＢＨＴ）、接着性付与剤
（例えばα−メチルスチレンビニルトルエン共重合体）
等を更に含有してもよい。The above specification of the resin material for forming the EVA resin layer 3 was made as a result of examining its film-forming properties, blocking properties, corrosion resistance, weather resistance, etc., as shown below, and if necessary, these were determined based on food hygiene considerations. Small amounts of non-problematic slip agents (e.g. fatty acid amide), antioxidants (e.g. BHT), adhesion agents (e.g. α-methylstyrene vinyl toluene copolymer)
etc. may further be contained.

ここに於いて、ＥＶＡ樹脂のＭＩ又は酢酸ビニル含有量
が上記規定値未満の場合は、押出積層フィルム化が困難
となり、且つ、ＥＶＡ樹脂層３の耐水及び耐寒性の改善
も充分とは云い難いものとなる。Here, if the MI or vinyl acetate content of the EVA resin is less than the above specified value, it will be difficult to make an extrusion laminated film, and the improvement in the water resistance and cold resistance of the EVA resin layer 3 will not be sufficient. Become something.

他方、これらの特定値が上記規定値を超えるときは、ブ
ロッキング性が悪化してやはり成膜困難となるものであ
る。On the other hand, when these specific values exceed the above-mentioned specified values, blocking properties deteriorate and film formation becomes difficult.

前記中間樹脂層２は、積層体の一体的接着強化層並びに
機械的衝撃の吸収層としての機能を有し、その素材は前
記の通り比較的柔軟性に富む樹脂材から選定されている
。The intermediate resin layer 2 functions as an integral adhesion reinforcing layer of the laminate and a mechanical shock absorbing layer, and the material thereof is selected from a relatively flexible resin material as described above.

又、上記積層材構造に於いて所要の場合は更に、接着補
助層として周知の所謂アンカーコート５、或いは美観、
耐候性向上等のためアルミニウム箔の他方の面上に印刷
及びオーバーコート６を設けてもよい。In addition, if necessary in the above laminated material structure, a so-called anchor coat 5, which is well known as an adhesion auxiliary layer, or an aesthetic layer,
Printing and an overcoat 6 may be provided on the other side of the aluminum foil to improve weather resistance and the like.

更に検討の結果、前記積層材を更に型付加工することな
く直接、蓋材として使用した場合、ＥＶＡ樹脂層３の瞬
間密封能が著るしく高いため、高速度熱封緘に当って容
器内気体の排出が不完全となり、密封容器の蓋部分が膨
張してしまうという新たな困難が生ずることが判明した
。As a result of further investigation, it was found that when the laminated material is used directly as a lid material without further molding processing, the instant sealing ability of the EVA resin layer 3 is extremely high, so that the gas inside the container is removed during high-speed heat sealing. It has been found that a new difficulty arises in that the discharge of the liquid is incomplete and the lid of the sealed container expands.

このような形状変形は不完全封緘の原因ともなるので一
般に好ましくないことは勿論であるが、特に、容器内容
物が乳酸菌飲料等の発酵生産物である場合、これら内容
物の過度の発酵、腐敗等による変質の検知手段としては
蓋部分の膨張度が一般に利用されている実情にあり、上
記困難の解決は回避され得ない。Of course, such shape deformation is generally undesirable as it can cause incomplete sealing, but it is particularly important when the contents of the container are fermented products such as lactic acid bacteria beverages, as they may cause excessive fermentation or spoilage of the contents. The degree of expansion of the lid portion is generally used as a means for detecting deterioration due to such factors, and the above-mentioned difficulty cannot be avoided.

加えて、この積層材の表面滑性は従来品と同程度のもの
でしかないので、この点での改良も又必要とされる。In addition, since the surface smoothness of this laminated material is only comparable to that of conventional products, improvements in this respect are also required.

本考案に依れば、上記各困難は積層材に対し、熱封緘性
に於ける容器内気体排出並びに表面滑性向上のための微
細凹凸模様４を更に型付加工することにより極めて効果
的に解決され得ることが見出された。According to the present invention, each of the above-mentioned difficulties can be overcome extremely effectively by further molding the laminated material with a fine uneven pattern 4 for evacuation of gas inside the container during heat sealability and for improving surface smoothness. It was found that the problem could be solved.

即わち、高速熱封緘に際して余分な容器内気体は微細凹
凸を介して排出され、他方、蓋材全体に微細凹凸を形成
することにより、蓋材両表面の熱封緘機及び成型機等の
機械部分との接触面積の減少が遠戚されて適切な表面滑
性が得られるものである。That is, during high-speed heat sealing, excess gas in the container is discharged through the fine irregularities, and on the other hand, by forming fine irregularities on the entire lid material, machines such as heat sealing machines and molding machines on both surfaces of the lid material are removed. Appropriate surface smoothness can be obtained by reducing the contact area with other parts.

又、容器内残存空気量の可及的減少は、空気中酸素によ
る内容物の酸化変質を抑制するものとなる。Further, reducing the amount of air remaining in the container as much as possible will suppress oxidative deterioration of the contents due to oxygen in the air.

ここで、蓋材が所要の熱封緘安定性（ヒートシール強度
）、気体排出性及び表面滑性の全てを満足し得るもので
あるためには、上記型付が次の１〜３の型付要因の少な
くとも１つ、好ましくは全てを充足するものでなければ
ならない Ｉ ＥＶＡ樹脂層３側の面に於いて、その凹凸全表面
積に占める対平面接触面積の割合いが約４０％以上であ
ること。Here, in order for the lid material to satisfy all of the required heat sealing stability (heat sealing strength), gas evacuation performance, and surface smoothness, the above molding must be performed according to the following moldings 1 to 3. At least one, preferably all of the factors must be satisfied.I On the surface on the side of the EVA resin layer 3, the ratio of the surface contact area to the total surface area of the unevenness should be about 40% or more. .

例えば、対平面接触面積が４０％未満である場合は、熱
封緘直前に容器口縁部と接触すべきＥＶＡ樹脂層３の面
積が少な過ぎて充分な熱封緘安定性が得られない。For example, if the surface contact area is less than 40%, the area of the EVA resin layer 3 that should be in contact with the container mouth edge immediately before heat sealing is too small, and sufficient heat sealing stability cannot be obtained.

２ 型付加工前の積層材の厚さに対し、蓋材の見掛けの
厚さが３倍以下であること。2. The apparent thickness of the lid material shall be no more than three times the thickness of the laminated material before molding.

これは、凹凸型の深さが必要以上に大きくなった場合、
熱封緘材（ＥＶＡ樹脂）の溶融による型の間隙の充填が
完全には期待し難いためであり、特に、熱封緘が所謂高
周波誘導加熱方式に依る場合、高圧力の印加が一般には
なされないためこの要因は一段と重要となる。This means that if the depth of the uneven mold becomes larger than necessary,
This is because it is difficult to expect that the gaps in the mold will be completely filled by melting the heat sealing material (EVA resin), and especially when heat sealing is based on the so-called high-frequency induction heating method, high pressure is generally not applied. This factor becomes even more important.

凹凸型の粗密さが、３５メツシュ相当〜２００メツシュ
相当、好ましくは６０メツシユ相当〜１２０メツシユ相
当の範囲内である。The density of the uneven pattern is within the range of 35 meshes to 200 meshes, preferably 60 meshes to 120 meshes.

他方、凹凸の形状、模様としては所謂絹日柄、布目柄、
水絞柄（梨地）、毛穴柄等々所望のものを適宜適用し得
るが、密封緘の完全を期するという観点からすれば、凹
凸部が不規則に配備される水絞柄、毛穴柄等のものがよ
り望ましい。On the other hand, the shape and pattern of the unevenness are so-called silk day pattern, cloth grain pattern,
A desired pattern such as a water squeeze pattern (nashiji) or a pore pattern can be applied as appropriate, but from the viewpoint of ensuring a perfect seal, a water squeeze pattern with irregularly arranged uneven parts, a pore pattern, etc. things are more desirable.

尚、本考案蓋材は上述のように予め積層形成された積層
材全体を型付加工して製造され得るのみならず、アルミ
ニウム箔１やＥＶＡ樹脂層３の形成材としてのＥＶＡ樹
脂フィルムを予め型付加工処理し、次いでこれらを貼合
等により積層形成しても提供され得る。The lid material of the present invention can not only be manufactured by molding the entire laminated material that has been laminated in advance as described above, but also can be manufactured by molding the entire laminated material that has been laminated in advance as described above. It can also be provided by molding and then laminating them by bonding or the like.

例えば、予め型付加工されたアルミニウム箔１に先ず中
間樹脂層２を積層し、次いで、適切なエンボス面を有す
るロールを使用してＥＶＡ樹脂層３を溶融押出積層する
等によっても、本考案蓋材は得られる。For example, the lid of the present invention can be manufactured by first laminating the intermediate resin layer 2 on the aluminum foil 1 which has been subjected to a molding process in advance, and then melt-extruding and laminating the EVA resin layer 3 using a roll having an appropriate embossed surface. material is obtained.

又、この場合の型形成条件は前述型付要因１〜３に準じ
て選定される。Moreover, the mold forming conditions in this case are selected according to the molding factors 1 to 3 described above.

以上詳述の通り本考案は、高速度熱封緘技術による飲食
物包装用として有用な新規熱封緘蓋材を提供するもので
あり、従来蓋材の利点を発展継承するものであることは
勿論、その欠点を完全に克服するものである。As detailed above, the present invention provides a new heat-sealing lid material useful for food and drink packaging using high-speed heat sealing technology, and of course inherits the advantages of conventional lid materials. This completely overcomes that drawback.

【図面の簡単な説明】[Brief explanation of the drawing]

添附図面は、本考案熱封緘蓋材の型付加工並びに積層構
造を示す部分拡大模式断面図である。 １・・・・・・アルミニウム箔、２・・・・・・中間樹
脂層、３・・・・・・ＥＶＡ樹脂層及び４・・・・・・
型付加工凹凸模様。The attached drawings are partially enlarged schematic cross-sectional views showing the molding process and laminated structure of the heat-sealing lid material of the present invention. 1... Aluminum foil, 2... Intermediate resin layer, 3... EVA resin layer, and 4...
Embossed textured pattern.

Claims (3)

【実用新案登録請求の範囲】[Scope of utility model registration request] （１）アルミニウム箔と、ポリオレフィン、ポリビニル
アルコール、アイオノマ及びエチレン共重合体系樹脂よ
り成る群から選択された少なくとも１種以上の樹脂材か
ら戊る中間樹脂層と、そのメルトイソデツクスが２〜４
０であり且つ酢酸ビニル含有量が５〜３０％であるエチ
レン・酢酸ビニル共重合樹脂層との一体的積層材であり
、 前記一体的積層材の両表面は熱封緘時に於ける容器内気
体排出又は表面滑性向上のための微細凹凸模様を有する
ことを特徴とする、飲食物容器用熱封緘蓋材。(1) An intermediate resin layer made of aluminum foil, at least one resin material selected from the group consisting of polyolefin, polyvinyl alcohol, ionomer, and ethylene copolymer resin, and a melt isodex of 2 to 4
0 and an ethylene/vinyl acetate copolymer resin layer with a vinyl acetate content of 5 to 30%. Alternatively, a heat-sealing lid material for food and drink containers, characterized by having a fine uneven pattern for improving surface smoothness. （２）前記一体的積層材全体に微細凹凸の型付がなされ
ていることを特徴とする実用新案登録請求の範囲第（１
）項に記載の飲食物容器用熱封緘蓋材。(2) Utility model registration claim No. 1, characterized in that the entire integral laminate material is patterned with fine irregularities.
) The heat-sealing lid material for food and drink containers as described in item 2. （３）前記一体的積層材のアルミニウム箔とエチレン・
酢酸ビニル共重合樹脂層とに微細凹凸の型付がなされて
いることを特徴とする実用新案登録請求の範囲第（１）
項に記載の飲食物容器用熱封緘蓋材。(3) Aluminum foil and ethylene of the integral laminate
Utility model registration claim No. (1) characterized in that the vinyl acetate copolymer resin layer is patterned with fine irregularities.
A heat-sealing lid material for food and drink containers as described in 2.