JP4028041B2

JP4028041B2 - Synthetic resin cap and closing device

Info

Publication number: JP4028041B2
Application number: JP26459097A
Authority: JP
Inventors: 浩一高松
Original assignee: 株式会社アルコア・クロージャー・システムズ
Priority date: 1997-09-29
Filing date: 1997-09-29
Publication date: 2007-12-26
Anticipated expiration: 2017-09-29
Also published as: JPH11100093A

Description

【０００１】
【発明の属する技術分野】
本発明は、タンパーエビデンス性を有する合成樹脂製キャップと、それを用いた閉止装置に関する。
【０００２】
【従来の技術】
近年、飲料容器として、ポリエチレンテレフタレート樹脂からなる合成樹脂製容器（ＰＥＴボトル）が賞用されている。合成樹脂製容器は、従来のガラス瓶に比べ、軽く、割れないという優れた特性を有している。
また、この種の合成樹脂製容器のキャップとしては、従来よりアルミ合金等の金属製キャップが使用されている。そして、この種の金属製キャップに代えて、合成樹脂製キャップの使用が検討されている。
この合成樹脂製キャップに関しては、例えば特開昭６２−２５１３５２号公報、特開平２−２９６６６６号公報に記載されたものが知られている。
これらの従来の合成樹脂製キャップは、口部に雄ネジが形成され、雄ネジ下方に環状膨出部が形成された容器に螺着嵌合され、該キャップは、天板部とその周縁から垂下した筒部とからなる合成樹脂製のキャップ本体と、そのキャップ本体の天板部内面に設けられた薄肉状のライナーとからなり、該キャップ本体は、その下部が複数の細いブリッジを残して周方向に形成された水平スコアによって、該水平スコアより上部の主部と、下部のタンパーエビデンスリング部とに区画されている。キャップ本体の主部の内壁面には、容器口部の雄ネジに螺着するネジ部が形成され、タンパーエビデンスリング部の内壁面には多数のウイングやタブ（係止突起）が起伏可能に設けられている。
また、容器としては、口部の上端部外周に雄ネジが形成され、該雄ネジの下方に、環状膨出部（ロッキングリング）が設けられたものが用いられる。
【０００３】
【発明が解決しようとする課題】
従来の合成樹脂製キャップは、ポリプロピレンなどの比較的硬い樹脂を用いてキャップ本体を作製し、その後で軟質の樹脂を天板部内面に施してライナーを形成していたので、材料及び加工コストがかかるため、コストが高くなるという問題があった。
また別な問題として、ＰＥＴボトルなどの合成樹脂製の容器は、加熱した液体を充填した場合など、高温状態から低温状態に急冷されると、口部上端が縮径して、上端が径方向内側に倒れてくる現象（以下、瓶口倒れ現象という）を生じる場合があり、この現象が発生すると、従来のライナー付キャップでは、密封性が損なわれ易くなる問題があった。
【０００４】
本発明は上記事情に鑑みてなされたもので、低コストで、かつ瓶口倒れ現象が発生する容器でも密封性を維持し得る、優れた合成樹脂製キャップと閉止装置の提供を課題としている。
【０００５】
【課題を解決するための手段】
本発明に係る合成樹脂製キャップは、天板部とその周縁から垂下した筒部とからなるキャップ本体を備え、該筒部が弱化ラインによって、該弱化ラインより上部の主部と、下部のタンパーエビデンスリング部とに区画され、該主部の内壁面にネジ部が形成され、かつタンパーエビデンスリング部の内壁面に起伏可能な複数の係止突起が設けられた合成樹脂製キャップにおいて、前記天板部の周縁から筒部上端部までのいずれかの位置に下方に延びる環状の弾発突起と、該弾発突起の径方向内方から、先端を筒部内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起とを、前記天板部と一体に設けてなり、前記シール突起は、該合成樹脂製キャップを容器口部に装着した際に、容器口部に当接して屈曲し、弾発突起を径方向外方に押圧して弾性的に曲げ変形させることを特徴とする。
【０００６】
本発明に係る閉止装置は、天板部とその周縁から垂下した筒部とからなるキャップ本体を備え、該筒部が切断可能な弱化ラインによって、該弱化ラインより上部の主部と、下部のタンパーエビデンスリング部とに区画され、該主部の内壁面にネジ部が形成され、かつタンパーエビデンスリング部の内壁面から突出した起伏可能な複数の係止突起が設けられた合成樹脂製キャップと、口部の上端部外周に雄ネジが形成され、該雄ネジの下方に、環状の膨出部が形成された容器とからなる閉止装置であって、前記合成樹脂製キャップは、前記天板部の周縁から筒部上端部までのいずれかの位置に下方に延びる環状の弾発突起と、該弾発突起の径方向内方から、先端を筒部内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起とを前記天板部と一体に設けてなり、該合成樹脂製キャップを容器口部に装着した際に、シール突起が容器口部に当接して屈曲し、弾発突起を径方向外方に押圧して弾性的に曲げ変形させるように構成したことを特徴とする。
この閉止装置において、前記合成樹脂製キャップは、係止突起として板状の起伏可能なタブを備えており、かつ前記容器は、前記膨出部に、該容器口部に装着された前記合成樹脂製キャップを開栓方向に回した際に、該キャップのタブに係合して該タブを押し下げる、キャップ開栓方向に向けて漸次下方に膨出する傾斜面を有する押下部が形成されたものとしてよい。
前記押下部は、前記傾斜面によって押し下げられたタブに係合してその上方への移動を阻止する延長段部が連設された構成としてよい。
前記延長段部の該傾斜面の反対側は、キャップ開栓方向に向けて漸次突出高さを減じる収納ガイド面とすることができる。
本発明の閉止装置は、容器口部に装着されたキャップを開栓方向に回転させ、ブリッジが切断される位置までの回転角度であるブリッジ切断角度が９０度以下である構成とすることができる。
【０００７】
【発明の実施の形態】
本発明の合成樹脂製キャップ（以下、キャップという）並びにそれを用いた閉止装置は、キャップの天板部の周縁から筒部上端部までのいずれかの位置に下方に延びる環状の弾発突起と、該弾発突起の径方向内方から、先端を筒部内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起とを天板部と一体に設けてなり、キャップを容器口部に装着した際に、シール突起が容器口部に当接して屈曲し、弾発突起を径方向外方に押圧するように構成したことによって、キャップ本体に別なライナー材を施すことがない、低コストのライナーレスキャップとなる。
また、キャップを容器口部に装着した状態では、弾発突起の弾性力でシール突起が容器口部の上端に押し付けられた状態で容器口部が密封されるので、確実に密封することができる。さらに、容器口部の上端が径方向内側に倒れ込む瓶口倒れ現象が生じた場合、その倒れ込みを弾発突起が径方向内方に戻ることで補償することができ、瓶口倒れ現象が生じた場合にも密封性を良好に維持し得る。
さらに、本発明の閉止装置において、容器の膨出部に、該容器口部に装着されたキャップを開栓方向に回した際に、キャップのタブ（係止突起）に係合してそれを押し下げる、キャップ開栓方向に向けて漸次下方に膨出する傾斜面を有する押下部が形成された構成、または該押下部に、前記傾斜面によって押し下げられたタブに係合してその上方への移動を阻止する延長段部を連設した構成とし、好ましくは延長段部の該傾斜面の反対側にキャップ開栓方向に向けて漸次突出高さを減じる収納ガイドを形成することによって、開栓時、キャップの係止突起が容器口部の押下部に当接して押し下げられ、それによってタンパーエビデンスリング部（以下、ＴＥリング部という）も押し下げられることから、容器の雄ネジに沿って上昇する主部とＴＥリング部とが急速に離間し、主部とＴＥリング部とを連結している弱化ラインが破断されるので、ブリッジ切断角度（Ｂ．Ｂ．Ａ）を９０度以下とすることができる。
【０００８】
図１ないし図４は、本発明に係るキャップおよび閉止装置の一例を示すものである。この閉止装置は、キャップ１と容器２１とからなっている。
キャップ１は、天板部２とその周縁から垂下した筒部３とからなり、ポリプロピレンなどの合成樹脂からなるキャップ本体４のみからなっている。キャップ本体４の筒部３は、複数の細いブリッジ６を残して該筒部３を周方向に沿って切断してなる水平スコア７（弱化ライン）によって、この水平スコア７より上部の主部８と、下部のタンパーエビデンスリング部９（以下、ＴＥリング部と記す）とに区画されている。主部８の内壁面にはネジ部１０が形成され、またＴＥリング部９の内壁面には、係止突起となる多数の板状のタブ１１が起伏可能に設けられている。なお、これらのタブ１１の基端部の直下には、タブ１１がその先端を下方に向けて倒れるのを防ぐための環状のビードを径方向内方側に突出形成しても良い。またＴＥリング部９には、水平スコア７の切断とほぼ同時に切断されてＴＥリング部９をバンド状に開環させる垂直弱化線を形成しても良い。
【０００９】
上記タブ１１は、容器に装着しない状態では、その先端を径方向内方に向けてほぼ水平となっており、キャップ１を容器口部２１Ａに装着する際に、雄ネジ２２や環状膨出部２３に当接すると上端を上向きに折り畳まれ、殆ど抵抗無く雄ネジ２２や環状膨出部２３を乗り越えることができるようになっている。本実施形態のキャップ１では、ＴＥリング部９の内周面に１２枚のタブ１１を列設している。
【００１０】
天板部２の周縁から筒部３上端部までの境界部分には、下方に延びる環状の弾発突起１２が設けられ、かつ天板部３の弾発突起１２の内方には、先端を筒部３内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起１３とが設けられている。これら弾発突起１２とシール突起１３とは、キャップ本体４と一体に設けられている。これら弾発突起１２とシール突起１３とは、キャップ１を容器口部２１Ａに装着した際に、シール突起１３が容器口部２１Ａに当接して屈曲し、弾発突起１２を径方向外方に押圧するように構成されている。
【００１１】
キャップ１の寸法は、特に限定されないが、汎用サイズのキャップにおいて好適な各寸法の範囲を以下に例示する。
タブ１１のＴＥリング部９内壁面からの突出長さは１．５〜４．０ｍｍ、好ましくは２．０〜３．０ｍｍ程度とされる。この突出長さが１．５ｍｍよりも小さいとタブの容器外面への当接が少なくなり開栓時にブリッジが切断され難くなり、突出長さが４．０ｍｍより大きいと成形が困難となり且つキャッピングも困難となる。また、タブ１１の形成個数、タブ１１の周方向長さおよび各タブ１１間の間隔は特に限定されないが、例えば内径２９ｍｍ程度のＴＥリング部９内壁面に１２個のタブを形成する場合には、タブ１１の周方向長さは４〜７ｍｍ程度、各タブ間の隙間は０．５〜３．５ｍｍ程度とされる。タブ１１の周方向長さが４ｍｍより小さいとタブ１１の容器口部への係止力が弱くなり、ブリッジ切断不良が生じるおそれがあり、周方向長さが７ｍｍより大きいとタブ１１の機械強度が強まって成形困難となる。
また、タブ１１の厚さは均一であっても、先端部側を厚くまたは薄くしても良い。通常はタブ１１の厚さは０．２〜１．２ｍｍ、好ましくは０．６〜１．０ｍｍ程度とされる。タブ厚さが０．２ｍｍより薄いと、タブが容易に折れ曲ってしまい、開栓時にＴＥリング部９を下方に案内することができず、ブリッジの切断不良を生じるおそれがあり、タブ厚さが１．２ｍｍより大きいと成形が困難でありキャッピング特性も悪くなるので好ましくない。タブ１１の基端部（ＴＥリング９内壁側）よりも先端部側の厚みを大きくする場合、例えば基端部長さが０．３〜０．７ｍｍ程度、先端部長さが１．５〜２．５ｍｍ程度とした場合、基端部厚さは０．４〜０．６ｍｍ、先端部厚さは０．５〜１．０ｍｍとするのが望ましい。タブの基端部厚さと先端部厚さとが上記範囲より小さいと、キャップ１を容器口部２１Ａに装着し、開栓方向に回した際に、タブ１１の強度（耐屈曲強度）が弱いために押下部２４に係合したタブが先端を下方に向けて屈曲され、ＴＥリング部９が主部８から切り離されずにキャップ１が容器口部２１Ａから外れてしまう場合があるので好ましくない。また、タブ１１の基端部厚さと先端部厚さとが上記範囲より大きいと、タブ１１の強度（耐屈曲強度）が不必要に増加して、キャップ１を容器口部２１Ａに装着する際に、タブ１１が押下部２４を通過する際の抵抗が大きくなり、キャップ１が所定の螺着終了角度まで十分に開栓できない不都合を生じるおそれがある。
【００１２】
上記ブリッジ６の形成個数は特に限定されないが、全部のブリッジ６の断面積の総和が０．３〜９．０ｍｍ²程度とされ、かつ引張時のブリッジ６の切断強度の総和が１０〜１８ｋｇ程度とされる。ブリッジ６の断面積の総和が９．０ｍｍ²より大きく、ブリッジ破断強度（引張時）が１８ｋｇより大きいと、開栓時にブリッジが切れずにキャップが外れたり、Ｂ.Ｂ.Ａが大きくなってタンパーエビデンス特性（開栓表示特性）が悪くなるおそれがある。ブリッジ６の断面積の総和が０．３ｍｍ²より小さく、ブリッジ破断強度（引張時）が１０ｋｇより小さいと、キャッピング時にブリッジが切断されてしまうおそれがある。
【００１３】
上記弾発突起１２は、キャップ１を容器口部２１Ａに装着した状態で、シール突起１３を介して容器口部２１Ａによって、径方向外方に向けて押され、開栓時には原位置に復帰する強度を備える必要がある。この弾発突起は、１．５ｍｍ程度の長さとした場合、その厚さは０．５〜１．０ｍｍ程度とされる。厚さが０．５ｍｍよりも小さいと、キャップ１装着時にシール突起１３の押圧力が弱くなり、密封性が悪化するおそれがある。また厚さが１．０ｍｍより大きいと、機械強度が高くなり、キャップの装着が困難となり、閉めトルク及び開栓トルクが高くなる不都合を生じる。
またシール突起１３は、キャップ１を容器口部２１Ａに装着した際に、口部２１Ａに当接して容易に屈曲し得る程度の可撓性を有している必要がある。好適には、容器口部２１Ａと弾発突起１２とに接する先端部の厚さが０．５〜１．０ｍｍ程度とされる。
【００１４】
容器２１は、その口部の上端部外周に雄ネジ２２が形成され、この雄ネジ２２の下方に環状膨出部２３が設けられ、かつ環状膨出部２３の下方に、鍔状のフランジ部２９が形成されている。
環状膨出部２３には、この容器口部２１Ａに装着された前記キャップ１を開栓方向（反時計方向）に回した際に、該キャップ１のタブ１１に係合してタブ１１を押し下げる押下部２４と、該押下部２４によって押し下げられたタブ１１に係合してその上方への移動を阻止する水平な延長段部２５とからなるブリッジ延伸手段２６が周方向に四つ設けられている。なお、ブリッジ延伸手段２６の形成個数は本実施形態に限定されず、１個または複数個で良い。
【００１５】
この押下部２４は、キャップ開栓時にタブ１１が当接する側が、キャップ開栓方向に向けて漸次下方に膨出する傾斜面とされている。また、延長段部２５の傾斜面の反対側の面は、キャップ開栓方向に向けて漸次突出高さを減じる収納ガイド面２７が形成されている。
押下部２４と環状膨出部とがなす傾斜角度は５〜５０度とされる。この角度が５０度より大きいと、容器口部２１Ａに装着されたキャップ１を開栓方向に回す際に、タブ１１が押し下げられる抵抗が強くなり、タブが押し下げられない場合が生じることになる。また、この角度が５度より小さいと、Ｂ.Ｂ.Ａが大きくなるので好ましくない。
【００１６】
環状膨出部２３から延長段部２５までの長さは、０．５〜４．０ｍｍ程度とされる。この長さが０．５ｍｍより小さいと、開栓時にタブ押下げの効果が十分発揮されずＢ.Ｂ.Ａが増加することになり、この長さが４．０ｍｍより大きいと、余肉部分が大きくなりコスト的に不利である。
また延長段部２５の水平部分の長さは３〜１０ｍｍとされる。この長さが３ｍｍより小さいと、Ｂ.Ｂ.Ａが増加することになり、１０ｍｍより大きいと、余肉部分が大きくなりコスト的に不利である。
また押下部２４の長さ（傾斜部長さ）は１．５〜８ｍｍとされる。この傾斜部長さが１．５ｍｍより小さいと、開栓時にタブ押下げの効果が十分発揮されなくなり、８ｍｍより大きいと、余肉部分が大きくなりコスト的に不利である。
収納ガイド面２７の傾斜角度は１５〜６０度とされる。
【００１７】
次に、本例による閉止装置の動作について説明する。
容器２１は、所望の内容液を充填した後、図示略のキャップ装着装置に搬送され、フランジ２９の下面を支承し、好ましくは懸吊状態で搬送しつつ、その口部２１Ａにキャップ１を被せ、時計方向に巻き締め、螺着嵌合する。
図２は、キャップ螺着初期の状態を示している。キャップ１が容器口部２１Ａに螺着されると、容器口部２１Ａの上端がシール突起１３に接する。
図３は、キャップ螺着中期の状態を示している。キャップ１の螺着に従い、キャップ１が下降すると、シール突起１３が口部上端によって押し上げられ、弾発突起１２の先端部に当接する。その後、シール突起１３は、容器口部２１Ａの上端部に沿って屈曲される。
図４は、キャップ螺着終了時の状態（装着状態）を示している。この装着状態にあっては、シール突起１３が容器口部２１Ａの上端部と弾発突起１２の間に挾まれて、容器口部２１Ａの上端部にぴったり押し付けられた状態となっており、容器口部２１Ａは完全に密封されている。弾発突起１２は、シール突起１３を介して径方向外方に向けて押し曲げられるが、元の位置に復帰する方向、すなわち径方向内方に向けてシール突起１３を付勢している。
【００１８】
容器口部２１Ａにキャップ１を装着する際には、キャップ１の各タブ１１が先端を上向きに折り畳まれた状態で環状膨出部２３を通過するので、ブリッジ６に余分な力が作用することはない。
また、キャップ１の装着最終段階において、装着状態で４個のブリッジ延伸手段２６と重なるタブ１１は、環状膨出部２３を通過し、先端を環状膨出部２３下方の容器口部外周面に当接するように径方向内方側に若干開いた状態で、ブリッジ延伸手段２６の収納ガイド面２７に接する。本例では、ブリッジ延伸手段２６にキャップ開栓方向に向けて漸次突出高さを減じる収納ガイド面２７を形成したことにより、上記タブ１１がタブ収納ガイド面２７に接して閉栓方向に移動する際に、このタブ１１がタブ収納ガイド面２７の傾斜に沿って、先端を上向きにして折り畳まれるので、ブリッジ６を切断することがない。
【００１９】
このようにして容器口部２１Ａにキャップ１を所定の閉栓トルク値で巻き締めてキャップ１を装着する。このキャップ装着状態にあっては、キャップ１の複数のタブのうち、ブリッジ延伸手段２６に重なるものを除く各タブ１１は、先端を環状膨出部２３下方の容器口部外周面に当接するように径方向内方側に若干開いた状態となる。また、ブリッジ延伸手段２６に重なるタブ１１は、先端を上向きに折り畳まれた状態となる。
容器２１の上端部は、上述した通り、シール突起１３が密着して密封状態になっている。この装着状態において、容器口部２１Ａの上端部が内側に向けて倒れ込む、瓶口倒れ現象が生じたとしても、弾発突起１２がその倒れ込みに応じて径方向内方側に移動することで倒れ込みが補償されることから、弾発突起１２とシール突起１３とによる容器口部２１Ａの密封状態は維持される。
【００２０】
このキャップ装着状態にある閉止装置の開栓時の動作を説明する。
キャップ１を開栓方向（反時計方向）に回すと、キャップ１の僅かな回転移動により、容器口部２１Ａに形成されたブリッジ延伸手段２６の押下部２４に、開栓方向側のタブ１１の先端部が接し、そのタブ１１の先端部が押下部２４の傾斜に従って徐々に押し下げられる。
押下部２４の傾斜に沿って押し下げられつつ、押下部２４を回転移動したタブ１１は、押下部２４から水平な延長段部２５にスムーズに移行する。タブ１１が延長段部２５に達した時点では、ＴＥリング部９は押し下げられる一方、主部８は雄ネジ２２に沿って上昇していることから、開栓方向への回転開始直後に主部８とＴＥリング部９は離間し、主部８とＴＥリング部９とを連結している複数の細いブリッジ６は延伸されて切断されるか、或いは切れ易い細糸状となる。
【００２１】
タブ１１が押下部２４から延長段部２５に移行した後、ＴＥリング部９の押し下げは無くなるが、主部８は依然として雄ネジ２２に従って上昇することによりブリッジ６は更に延伸され、タブ１１が延長段部２５を移動する途中で完全に切断される。
その後、主部８を更に開栓方向に回転させることにより、主部８を容器口部２１Ａから取り外す。
【００２２】
本例による閉止装置は、容器２１に、その口部２１Ａに装着されたキャップ１を開栓方向に回した際に、キャップ１のタブ１１に係合して押し下げる押下部２４と、該押下部２４によって押し下げられたタブ１１に係合してその上方への移動を阻止する延長段部２５とを有する少なくとも１つのブリッジ延伸手段２６を設けたことにより、容器口部２１Ａに装着したキャップ１を開栓方向に回すと、ブリッジ延伸手段２６の押下部２４側に隣接したタブ１１が押下部２４に当接して押し下げられ、それによってＴＥリング部９も押し下げられることから、容器２１の雄ネジ２２に沿って上昇する主部８とＴＥリング部９とが急速に離間し、主部８とＴＥリング部９とを連結している複数の細いブリッジ６が延伸される。さらに該タブ１１が延長段部２５に移行した後、ＴＥリング部９は上昇が阻止されるとともに、主部８は依然として雄ネジ２２に沿って上昇することから、該ブリッジ６が切断され、ＴＥリング部９が主部８から切り離された状態となって、開栓したことが明示される。従って、この閉止装置によれば、容器口部２１Ａに装着されたキャップ１を開栓方向に回転させ、ブリッジ６が切断される位置までの回転角度であるブリッジ切断角度（Ｂ.Ｂ.Ａ）を９０度以下、望ましくは４５度以下と小さくすることができる。
また、このキャップ１は、キャップ１の天板部２の周縁から筒部上端部の境界部に下方に延びる環状の弾発突起１２と、その径方向内方から、先端を筒部３内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起１３とを天板部２と一体に設けてなり、キャップ１を容器口部２１Ａに装着した際に、シール突起１３が容器口部２１Ａに当接して屈曲し、弾発突起１２を径方向外方に押圧するように構成したことによって、キャップ本体４に別なライナー材を施すことがない、低コストのライナーレスキャップとなる。
またキャップ１を容器口部２１Ａに装着した状態では、弾発突起１２の弾性力でシール突起１３が容器口部２１Ａの上端に押し付けられた状態で密封されるので、確実に密封することができる。さらに、容器口部２１Ａの上端が径方向内側に倒れ込む瓶口倒れ現象が生じた場合、その倒れ込みを弾発突起１２が径方向内方に戻ることで補償することができ、瓶口倒れ現象が生じた場合にも密封性を維持し得る。
【００２３】
なお、本発明は上述した例に限定されることなく、各種の変更や変形が可能である。
先の実施形態では、容器２１に、環状膨出部２３から、傾斜面を有する押下部２４と、水平な延長段部２５とを有するブリッジ延伸手段２６を設けた構成としたが、ブリッジ延伸手段２６を設けていない容器、例えば特開昭６２−２５１３５２号公報、特開平２−２９６６６６号公報に記載されているように環状膨出部のみを形成した容器を用いても良い。またブリッジ延伸手段２６を設ける場合、延長段部２５を省き、開栓時にブリッジ６を確実に切断できる押下部２４のみを設けた構成としても良い。
また、先の実施形態では、係止突起として、ＴＥリング部に複数のタブ１１を列設した構成としたが、タブ１１に代えて、特開昭６２−２５１３５２号公報に記載されているようなウイングを配した構成としても良い。
【００２４】
【実施例】
図１に示す閉止装置を作製し、その密封性能を確認した。
ポリプロピレンを材料として、外径３３ｍｍ、高さ１７ｍｍ、弾発突起の突出長さ１．５ｍｍ、シール突起の長さ４ｍｍ、先端部厚さ０．５ｍｍの図１に示すキャップ１を作製した。
弾発突起の厚さを０．３〜１．５ｍｍまで変えたキャップを試作し、図１に示す口元構造を有する容器（ＰＥＴボトル）に８５℃の温水を充填し、直後にアルコア社製のキャッピングマシンを用いてキャップを装着し、密封性を調べた。
（密封性試験）
充填冷却後のサンプルを５５℃の恒温槽中に９時間、室温に１５時間のサイクルを２回繰り返し、更に５℃の冷蔵庫にて、横倒し保存２４時間後の漏れの有無をチェックする。
（結果）
・弾発突起の厚さを０．３ｍｍとしたサンプル１は５０本中９本に漏れ発生。
・弾発突起の厚さを０．５ｍｍとしたサンプル２は５０本中漏れ発生無し。
・弾発突起の厚さを１．０ｍｍとしたサンプル３は５０本中漏れ発生無し。
・弾発突起の厚さを１．５ｍｍとしたサンプル４は５０本中１０本に漏れ発生。
この結果、弾発突起の突出長さを１．５ｍｍとした場合、良好な弾発突起の厚さは０．３ｍｍ以上１．５ｍｍ未満、好ましくは０．５〜１．３ｍｍ程度、より好ましくは０．５〜１．０ｍｍ程度であることが判った。なお、上記サンプル１における漏れは、弾発突起の弾性力が弱いために、シール突起を容器口部に押し付ける圧力が弱かったために発生し、またサンプル４における漏れは、弾発突起の剛性が高く、キャップの装着が不完全であったことに起因する。
【００２５】
【発明の効果】
以上説明したように、本発明の合成樹脂製キャップ並びにそれを用いた閉止装置は、合成樹脂製キャップの天板部の周縁から筒部上端部までのいずれかの位置に下方に延びる環状の弾発突起と、該弾発突起の径方向内方から、先端を筒部内壁に向けて延び出し、少なくとも先端部が可撓性を有する環状のシール突起とを天板部と一体に設けてなり、合成樹脂製キャップを容器口部に装着した際に、シール突起が容器口部に当接して屈曲し、弾発突起を径方向外方に押圧するように構成したことによって、キャップ本体に別なライナー材を施すことがないライナーレスキャップにおいて良好な密封性が得られ、低コストの合成樹脂製キャップを提供することができる。
また、合成樹脂製キャップを容器口部に装着した状態では、弾発突起の弾性力でシール突起が容器口部の上端に押し付けられた状態で容器口部が密封されるので、確実に密封することができる。さらに、容器口部の上端が径方向内側に倒れ込む瓶口倒れ現象が生じた場合、その倒れ込みを弾発突起が径方向内方に戻ることで補償することができ、瓶口倒れ現象が生じた場合にも密封性を維持することができるので、容器への適応性に優れている。
【図面の簡単な説明】
【図１】本発明の閉止装置の一例を示す一部断面視した正面図。
【図２】同じ閉止装置のキャップ螺着初期の状態を示す要部断面図。
【図３】同じくキャップ螺着中期の状態を示す要部断面図。
【図４】同じくキャップ螺着終了状態を示す要部断面図。
【符号の説明】
１……合成樹脂製キャップ、２……天板部、３……筒部、４……キャップ本体、６……ブリッジ、７……水平スコア、８……主部、９……ＴＥリング部、１０……ネジ部、１１……タブ、１２……弾発突起、１３……シール突起、２１……容器、２１Ａ……容器口部、２２……雄ネジ、２３……環状膨出部、２４……押下部、２５……延長段部、２６……ブリッジ延伸手段、２７……収納ガイド面。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin cap having tamper-evidence and a closing device using the same.
[0002]
[Prior art]
In recent years, a synthetic resin container (PET bottle) made of polyethylene terephthalate resin has been used as a beverage container. Synthetic resin containers are lighter than conventional glass bottles and have excellent properties of not breaking.
Further, a metal cap such as an aluminum alloy has been conventionally used as a cap for this type of synthetic resin container. In place of this kind of metal cap, use of a synthetic resin cap is being studied.
As this synthetic resin cap, for example, those described in Japanese Patent Application Laid-Open Nos. 62-251352 and 2-296666 are known.
These conventional synthetic resin caps are screwed into a container in which a male screw is formed in the mouth and an annular bulge is formed below the male screw. It consists of a cap body made of synthetic resin consisting of a hanging cylinder part and a thin liner provided on the inner surface of the top plate part of the cap body, and the lower part of the cap body leaves a plurality of thin bridges. A horizontal score formed in the circumferential direction is divided into a main part above the horizontal score and a tamper evidence ring part below. On the inner wall surface of the main part of the cap body, a threaded part that is screwed onto the male thread of the container mouth is formed, and numerous wings and tabs (locking protrusions) can be raised and lowered on the inner wall surface of the tamper evidence ring part. Is provided.
In addition, as the container, a container in which a male screw is formed on the outer periphery of the upper end portion of the mouth portion and an annular bulging portion (locking ring) is provided below the male screw is used.
[0003]
[Problems to be solved by the invention]
In the conventional synthetic resin cap, the cap body is made using a relatively hard resin such as polypropylene, and then a soft resin is applied to the inner surface of the top plate to form a liner. Therefore, there is a problem that the cost is increased.
As another problem, when a synthetic resin container such as a PET bottle is rapidly cooled from a high temperature state to a low temperature state such as when a heated liquid is filled, the upper end of the mouth is reduced in diameter and the upper end is in the radial direction. There is a case where a phenomenon of falling inside (hereinafter referred to as a bottle mouth falling phenomenon) occurs. When this phenomenon occurs, the conventional liner cap has a problem that the sealing performance is easily impaired.
[0004]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an excellent synthetic resin cap and closing device that can maintain hermeticity even in a container that is low-cost and in which a bottle mouth collapse phenomenon occurs.
[0005]
[Means for Solving the Problems]
The synthetic resin cap according to the present invention includes a cap body composed of a top plate portion and a cylindrical portion hanging from the periphery thereof. The cylindrical portion is formed by a weakening line, a main portion above the weakening line, and a lower tamper. A synthetic resin cap that is partitioned into an evidence ring portion, a thread portion is formed on an inner wall surface of the main portion, and a plurality of locking projections that can be raised and lowered are provided on the inner wall surface of the tamper evidence ring portion; An annular elastic projection extending downward to any position from the peripheral edge of the plate portion to the upper end portion of the cylindrical portion, and a tip extending from the radially inner side of the elastic projection toward the inner wall of the cylindrical portion, at least the distal end An annular seal projection having a flexible portion is provided integrally with the top plate portion, and the seal projection contacts the container mouth when the synthetic resin cap is attached to the container mouth. Bends in contact and bends It is pressed against the direction outwards, characterized in that for elastically bending deformation.
[0006]
The closing device according to the present invention includes a cap body including a top plate portion and a cylindrical portion hanging from the periphery thereof, and a main portion above the weakening line and a lower portion of the weakening line that can be cut by the cylindrical portion. A synthetic resin cap that is partitioned into a tamper-evidence ring portion, a thread portion is formed on the inner wall surface of the main portion, and a plurality of undulating locking projections protruding from the inner wall surface of the tamper-evidence ring portion are provided A closing device comprising a container in which a male screw is formed on the outer periphery of the upper end portion of the mouth, and an annular bulging portion is formed below the male screw, wherein the synthetic resin cap is the top plate An annular elastic projection extending downward to any position from the peripheral edge of the tube portion to the upper end portion of the cylindrical portion, and a tip extending from the radially inner side of the elastic projection toward the inner wall of the cylindrical portion, at least the distal end portion An annular seal projection having flexibility When the synthetic resin cap is attached to the container mouth portion, the seal projection comes into contact with the container mouth portion and bends so that the elastic projection is radially outward. It is characterized by being configured to be pressed and elastically bend and deform .
In this closing device, the synthetic resin cap includes a plate-like undulating tab as a locking projection, and the container is attached to the bulging portion and the synthetic resin attached to the container mouth portion. A push-down portion having an inclined surface that gradually bulges downward in the cap opening direction is formed, which engages with the tab of the cap and pushes down the tab when the cap is rotated in the opening direction. As good as
The pressing portion may have a configuration in which an extension step portion that engages with a tab pressed down by the inclined surface and prevents the tab from moving upward is provided continuously.
The opposite side of the inclined surface of the extension step portion can be a storage guide surface that gradually reduces the protruding height in the cap opening direction.
The closing device of the present invention can be configured such that the cap attached to the container mouth is rotated in the opening direction, and the bridge cutting angle, which is the rotation angle to the position at which the bridge is cut, is 90 degrees or less. .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
A synthetic resin cap (hereinafter referred to as a cap) and a closing device using the same according to the present invention include an annular elastic protrusion that extends downward to any position from the periphery of the top plate portion of the cap to the upper end portion of the cylindrical portion. The tip of the projecting protrusion extends from the radially inner side toward the inner wall of the cylindrical part, and at least the tip part is provided with an annular sealing protrusion having flexibility so as to be integrated with the top plate part. Applying another liner material to the cap body by configuring the seal projection to bend against the container mouth and bend when it is attached to the container mouth, and press the elastic projection radially outward. This is a low-cost linerless cap with no friction.
In addition, when the cap is attached to the container mouth portion, the container mouth portion is sealed in a state where the seal projection is pressed against the upper end of the container mouth portion by the elastic force of the elastic projection, so that the container mouth portion can be reliably sealed. . Furthermore, when a bottle mouth falling phenomenon occurs in which the upper end of the container mouth part falls inward in the radial direction, the falling can be compensated by returning the projecting protrusion radially inward, and the bottle mouth falling phenomenon has occurred. Even in this case, the sealing performance can be maintained well.
Furthermore, in the closing device of the present invention, when the cap attached to the container mouth is turned to the bulging portion of the container in the opening direction, the cap is engaged with the tab (locking protrusion) of the cap. A push-down portion having an inclined surface that gradually bulges downward toward the cap opening direction is formed, or the push-down portion engages with a tab pushed down by the inclined surface and moves upward. An extension step portion for preventing movement is provided continuously, and preferably, an opening guide is formed on the opposite side of the inclined surface of the extension step portion by forming a storage guide that gradually reduces the protruding height in the cap opening direction. At this time, the locking projection of the cap comes into contact with the pressing portion of the container mouth portion and is pushed down, and the tamper evidence ring portion (hereinafter referred to as TE ring portion) is also pushed down, so that it rises along the male screw of the container. Main part and E ring portion and is rapidly separated, since the weakening line which connects the main portion and the TE ring portion is broken, the bridge cutting angle (B.B.A) can be less than 90 degrees.
[0008]
1 to 4 show an example of a cap and a closing device according to the present invention. The closing device includes a cap 1 and a container 21.
The cap 1 is composed of a top plate portion 2 and a cylindrical portion 3 hanging from the periphery thereof, and is composed only of a cap body 4 made of a synthetic resin such as polypropylene. The cylindrical portion 3 of the cap body 4 is composed of a main portion 8 above the horizontal score 7 by a horizontal score 7 (weakening line) formed by cutting the cylindrical portion 3 along the circumferential direction while leaving a plurality of thin bridges 6. And a lower tamper evidence ring part 9 (hereinafter referred to as a TE ring part). A screw portion 10 is formed on the inner wall surface of the main portion 8, and a large number of plate-like tabs 11 serving as locking protrusions are provided on the inner wall surface of the TE ring portion 9 so as to be raised and lowered. An annular bead may be formed directly below the base end portion of these tabs 11 to prevent the tabs 11 from tipping downward and projecting radially inward. Further, the TE ring portion 9 may be formed with a vertical weakening line that is cut almost simultaneously with the cutting of the horizontal score 7 and opens the TE ring portion 9 in a band shape.
[0009]
When the tab 11 is not attached to the container, the tip of the tab 11 is substantially horizontal with the tip inward in the radial direction. When the cap 1 is attached to the container mouth portion 21A, the male screw 22 or the annular bulging portion When it comes into contact with 23, the upper end is folded upward so that the male screw 22 and the annular bulging portion 23 can be overcome with almost no resistance. In the cap 1 of the present embodiment, twelve tabs 11 are arranged on the inner peripheral surface of the TE ring portion 9.
[0010]
An annular elastic projection 12 extending downward is provided at the boundary portion from the peripheral edge of the top plate portion 2 to the upper end portion of the cylindrical portion 3, and a tip is provided inside the elastic projection 12 of the top plate portion 3. An annular seal protrusion 13 that extends toward the inner wall of the cylindrical portion 3 and that has at least a flexible end portion is provided. The elastic projection 12 and the seal projection 13 are provided integrally with the cap body 4. When the cap 1 is attached to the container mouth portion 21A, the resilient projection 12 and the seal projection 13 are bent by the seal projection 13 coming into contact with the container mouth portion 21A, so that the resilient projection 12 is radially outward. It is comprised so that it may press.
[0011]
Although the dimension of the cap 1 is not specifically limited, the range of each dimension suitable in the cap of a general purpose size is illustrated below.
The protruding length of the tab 11 from the inner wall surface of the TE ring portion 9 is 1.5 to 4.0 mm, preferably about 2.0 to 3.0 mm. If the protruding length is less than 1.5 mm, the tab does not come into contact with the outer surface of the container and the bridge is difficult to be cut when opened. If the protruding length is greater than 4.0 mm, molding becomes difficult and capping is also difficult. It becomes difficult. The number of tabs 11 formed, the circumferential length of the tabs 11 and the spacing between the tabs 11 are not particularly limited. For example, when twelve tabs are formed on the inner wall surface of the TE ring portion 9 having an inner diameter of about 29 mm. The circumferential length of the tab 11 is about 4 to 7 mm, and the gap between the tabs is about 0.5 to 3.5 mm. When the circumferential length of the tab 11 is smaller than 4 mm, the locking force of the tab 11 to the container mouth portion is weakened, and there is a possibility that the bridge cutting failure may occur. When the circumferential length is larger than 7 mm, the mechanical strength of the tab 11 is increased. Strengthens and becomes difficult to mold.
Moreover, even if the thickness of the tab 11 is uniform, the tip end side may be made thicker or thinner. Usually, the thickness of the tab 11 is 0.2 to 1.2 mm, preferably about 0.6 to 1.0 mm. If the tab thickness is less than 0.2 mm, the tab is easily bent, the TE ring portion 9 cannot be guided downward when opening the plug, and there is a possibility that the cutting failure of the bridge may occur. If it is larger than 1.2 mm, molding is difficult and capping characteristics are also deteriorated, which is not preferable. When the thickness of the tip end side is made larger than the base end portion (the inner wall side of the TE ring 9) of the tab 11, for example, the base end portion length is about 0.3 to 0.7 mm, and the tip end length is 1.5 to 2. When the thickness is about 5 mm, the base end thickness is preferably 0.4 to 0.6 mm, and the tip end thickness is preferably 0.5 to 1.0 mm. If the base end portion thickness and the tip end portion thickness of the tab are smaller than the above ranges, the strength (flexible strength) of the tab 11 is weak when the cap 1 is attached to the container mouth portion 21A and rotated in the opening direction. Since the tab engaged with the pressing portion 24 is bent with the tip downward, the TE ring portion 9 is not separated from the main portion 8 and the cap 1 may be detached from the container mouth portion 21A. Further, when the base end portion thickness and the tip end portion thickness of the tab 11 are larger than the above ranges, the strength (bending strength) of the tab 11 increases unnecessarily, and when the cap 1 is attached to the container mouth portion 21A. The resistance when the tab 11 passes through the pressing portion 24 increases, and there is a risk that the cap 1 cannot be fully opened up to a predetermined screwing end angle.
[0012]
The number of the bridges 6 formed is not particularly limited, but the total cross-sectional area of all the bridges 6 is about 0.3 to 9.0 mm ² and the total cutting strength of the bridges 6 is about 10 to 18 kg when pulled. It is said. If the sum of the cross-sectional areas of the bridge 6 is greater than 9.0 mm ² and the bridge breaking strength (when tensile) is greater than 18 kg, the bridge will not be cut off when the cap is opened, and the BBA will increase. Tamper evidence characteristics (opening display characteristics) may be deteriorated. If the total cross-sectional area of the bridge 6 is smaller than 0.3 mm ² and the bridge breaking strength (when tensile) is smaller than 10 kg, the bridge may be cut during capping.
[0013]
The elastic projection 12 is pushed radially outward by the container mouth portion 21A through the seal projection 13 with the cap 1 being mounted on the container mouth portion 21A, and returns to the original position when the cap is opened. It is necessary to have strength. When the length of the elastic protrusion is about 1.5 mm, the thickness is about 0.5 to 1.0 mm. If the thickness is less than 0.5 mm, the pressing force of the seal projection 13 becomes weak when the cap 1 is mounted, and the sealing performance may be deteriorated. On the other hand, when the thickness is larger than 1.0 mm, the mechanical strength is increased, the cap is difficult to be attached, and the closing torque and the opening torque are increased.
Further, when the cap 1 is attached to the container mouth portion 21A, the seal protrusion 13 needs to have such a degree of flexibility that it can be easily bent by coming into contact with the mouth portion 21A. Preferably, the thickness of the tip portion in contact with the container mouth portion 21A and the elastic projection 12 is about 0.5 to 1.0 mm.
[0014]
The container 21 has a male screw 22 formed on the outer periphery of the upper end of the mouth, an annular bulge 23 is provided below the male screw 22, and a flange-like flange portion below the annular bulge 23. 29 is formed.
The annular bulge 23 is engaged with the tab 11 of the cap 1 to push down the tab 11 when the cap 1 attached to the container mouth portion 21A is rotated in the opening direction (counterclockwise). Four bridge extending means 26 are provided in the circumferential direction, each of which includes a pressing portion 24 and a horizontal extension step portion 25 that engages with the tab 11 pushed down by the pressing portion 24 and prevents the tab 11 from moving upward. Yes. The number of bridge extending means 26 formed is not limited to this embodiment, and may be one or more.
[0015]
The pressing portion 24 has an inclined surface that gradually bulges downward toward the cap opening direction on the side where the tab 11 abuts when the cap is opened. A storage guide surface 27 is formed on the surface opposite to the inclined surface of the extension step portion 25 to gradually reduce the protruding height in the cap opening direction.
The inclination angle formed by the pressing portion 24 and the annular bulging portion is 5 to 50 degrees. When this angle is larger than 50 degrees, when the cap 1 attached to the container mouth portion 21A is turned in the opening direction, the resistance of the tab 11 being pushed down becomes strong, and the tab may not be pushed down. Also, if this angle is smaller than 5 degrees, BBA will increase, which is not preferable.
[0016]
The length from the annular bulging part 23 to the extension step part 25 is about 0.5 to 4.0 mm. If this length is smaller than 0.5 mm, the effect of tab pressing at the time of opening is not sufficiently exhibited, and BBA will increase. If this length is larger than 4.0 mm, the surplus portion Is large and disadvantageous in terms of cost.
The length of the horizontal portion of the extension step 25 is 3 to 10 mm. If this length is smaller than 3 mm, BBA will increase, and if it is larger than 10 mm, the surplus portion becomes large, which is disadvantageous in terms of cost.
The length of the pressing portion 24 (inclined portion length) is 1.5 to 8 mm. If the length of the inclined portion is smaller than 1.5 mm, the tab pressing effect is not sufficiently exhibited at the time of opening, and if it is larger than 8 mm, the surplus portion becomes large, which is disadvantageous in terms of cost.
The inclination angle of the storage guide surface 27 is 15 to 60 degrees.
[0017]
Next, the operation of the closing device according to this example will be described.
After the container 21 is filled with a desired content liquid, the container 21 is transported to a cap mounting device (not shown), supports the lower surface of the flange 29, and preferably transports in a suspended state while covering the mouth 21A with the cap 1. , Tighten clockwise and screw.
FIG. 2 shows an initial state of the cap screwing. When the cap 1 is screwed into the container mouth portion 21 </ b> A, the upper end of the container mouth portion 21 </ b> A contacts the seal protrusion 13.
FIG. 3 shows a state in the middle of screwing the cap. When the cap 1 descends according to the screwing of the cap 1, the seal projection 13 is pushed up by the upper end of the mouth and comes into contact with the tip of the elastic projection 12. Thereafter, the seal protrusion 13 is bent along the upper end portion of the container mouth portion 21A.
FIG. 4 shows a state (attached state) at the end of screwing of the cap. In this mounted state, the seal projection 13 is sandwiched between the upper end portion of the container mouth portion 21A and the elastic projection 12 and is pressed exactly against the upper end portion of the container mouth portion 21A. The mouth portion 21A is completely sealed. The elastic protrusion 12 is pushed and bent radially outward through the seal protrusion 13, but urges the seal protrusion 13 in a direction to return to the original position, that is, radially inward.
[0018]
When the cap 1 is attached to the container mouth portion 21A, each tab 11 of the cap 1 passes through the annular bulging portion 23 with the tip folded upward, so that extra force acts on the bridge 6. There is no.
In the final stage of attaching the cap 1, the tab 11 that overlaps the four bridge extension means 26 in the attached state passes through the annular bulging portion 23, and the tip is on the outer peripheral surface of the container mouth below the annular bulging portion 23. It is in contact with the storage guide surface 27 of the bridge extension means 26 in a state of being slightly opened radially inward so as to come into contact. In this example, the bridge extending means 26 is formed with the storage guide surface 27 that gradually reduces the protruding height in the cap opening direction, so that the tab 11 moves in the plug closing direction in contact with the tab storage guide surface 27. In addition, since the tab 11 is folded along the inclination of the tab storage guide surface 27 with the tip thereof facing upward, the bridge 6 is not cut.
[0019]
In this way, the cap 1 is attached to the container mouth portion 21A by winding the cap 1 with a predetermined closing torque value. In this cap mounting state, the tabs 11 except for the tabs of the cap 1 that overlap the bridge extending means 26 are in contact with the outer peripheral surface of the container mouth below the annular bulge 23. It is in a state of being slightly opened radially inward. Further, the tab 11 overlapping the bridge extending means 26 is in a state where the tip is folded upward.
As described above, the seal projection 13 is in close contact with the upper end of the container 21 and is in a sealed state. In this mounted state, even if the bottle mouth collapse phenomenon occurs in which the upper end portion of the container mouth portion 21A falls inward, the elastic projection 12 falls by moving radially inward according to the fall. Therefore, the sealed state of the container mouth portion 21A by the elastic projection 12 and the seal projection 13 is maintained.
[0020]
The operation at the time of opening of the closing device in the cap mounting state will be described.
When the cap 1 is turned in the opening direction (counterclockwise), the tab 1 on the opening direction side of the pressing portion 24 of the bridge extension means 26 formed in the container mouth portion 21A is moved by a slight rotational movement of the cap 1. The tip end comes into contact, and the tip end of the tab 11 is gradually pushed down according to the inclination of the pressing portion 24.
The tab 11 that has been pushed down along the inclination of the pressing portion 24 and rotationally moved the pressing portion 24 smoothly transitions from the pressing portion 24 to the horizontal extension step portion 25. When the tab 11 reaches the extension step portion 25, the TE ring portion 9 is pushed down, while the main portion 8 rises along the male screw 22, so that the main portion immediately after the start of rotation in the plug opening direction. 8 and the TE ring portion 9 are separated from each other, and the plurality of thin bridges 6 connecting the main portion 8 and the TE ring portion 9 are stretched and cut, or are easily cut into a thin thread shape.
[0021]
After the tab 11 shifts from the pressing portion 24 to the extension step portion 25, the TE ring portion 9 is not pushed down, but the main portion 8 still rises according to the male screw 22, whereby the bridge 6 is further extended and the tab 11 is extended. It is completely cut off while moving the step portion 25.
Then, the main part 8 is removed from the container mouth part 21A by further rotating the main part 8 in the opening direction.
[0022]
The closing device according to the present example includes a pressing unit 24 that engages and pushes down the tab 11 of the cap 1 when the cap 1 attached to the mouth 21A of the container 21 is rotated in the opening direction. The cap 1 attached to the container mouth portion 21A is provided by providing at least one bridge extending means 26 having an extension step portion 25 that engages with the tab 11 pushed down by 24 and prevents its upward movement. When it is turned in the opening direction, the tab 11 adjacent to the pressing portion 24 side of the bridge extending means 26 is pressed against the pressing portion 24 and is pressed down, whereby the TE ring portion 9 is also pressed down. The main part 8 and the TE ring part 9 rising along the line are rapidly separated, and a plurality of thin bridges 6 connecting the main part 8 and the TE ring part 9 are extended. Further, after the tab 11 moves to the extension step 25, the TE ring portion 9 is prevented from rising, and the main portion 8 still rises along the male screw 22, so that the bridge 6 is cut, and the TE It is clearly shown that the ring portion 9 is disconnected from the main portion 8 and is opened. Therefore, according to this closing device, the bridge cutting angle (BB), which is the rotation angle to the position at which the bridge 6 is cut by rotating the cap 1 attached to the container mouth portion 21A in the opening direction. Can be reduced to 90 degrees or less, desirably 45 degrees or less.
Further, the cap 1 has an annular elastic projection 12 extending downward from the periphery of the top plate portion 2 of the cap 1 to the boundary portion of the upper end portion of the cylindrical portion, and the tip thereof from the inner side in the radial direction to the inner wall of the cylindrical portion 3. An annular seal projection 13 extending at least at the tip and having flexibility is provided integrally with the top plate 2, and when the cap 1 is attached to the container mouth portion 21A, the seal projection 13 is A low-cost linerless cap that does not apply another liner material to the cap body 4 by being configured to abut against the mouth portion 21A and bend and press the elastic protrusion 12 radially outward. Become.
When the cap 1 is attached to the container mouth portion 21A, the sealing projection 13 is pressed against the upper end of the container mouth portion 21A by the elastic force of the elastic projection 12, so that the sealing can be ensured. . Further, when a bottle mouth falling phenomenon occurs in which the upper end of the container mouth portion 21A falls inward in the radial direction, the falling can be compensated by the elastic protrusion 12 returning inward in the radial direction, and the bottle mouth falling phenomenon occurs. Even if it occurs, the sealing performance can be maintained.
[0023]
In addition, this invention is not limited to the example mentioned above, A various change and deformation | transformation are possible.
In the previous embodiment, the container 21 is provided with the bridge extending means 26 having the pressing part 24 having the inclined surface and the horizontal extending step part 25 from the annular bulging part 23. For example, a container in which only an annular bulge is formed as described in JP-A-62-251352 and JP-A-2-296666 may be used. When the bridge extending means 26 is provided, the extension step portion 25 may be omitted, and only the pressing portion 24 that can reliably cut the bridge 6 at the time of opening may be provided.
In the previous embodiment, a plurality of tabs 11 are arranged in the TE ring portion as locking protrusions. However, instead of the tabs 11, as described in Japanese Patent Application Laid-Open No. Sho 62-251352. It is good also as a structure which arranged the wing.
[0024]
【Example】
The closing device shown in FIG. 1 was produced and its sealing performance was confirmed.
Using polypropylene as a material, a cap 1 shown in FIG. 1 having an outer diameter of 33 mm, a height of 17 mm, a protruding length of the projecting protrusion of 1.5 mm, a length of the sealing protrusion of 4 mm, and a tip thickness of 0.5 mm was produced.
A cap with a thickness of the bullet projection of 0.3 to 1.5 mm was made as a prototype, and a container (PET bottle) having a mouth structure shown in FIG. 1 was filled with 85 ° C. warm water. A cap was attached using a capping machine, and the sealing property was examined.
(Sealing test)
The sample after filling and cooling is repeated twice in a constant temperature bath at 55 ° C. for 9 hours and at room temperature for 15 hours, and then laid down in a 5 ° C. refrigerator to check for leaks after 24 hours of storage.
(result)
-Sample 1 with a bullet projection thickness of 0.3 mm leaked in 9 out of 50 samples.
-No leakage occurred in 50 samples 2 with a thickness of 0.5 mm.
-No leakage occurred in Sample 3 with a thickness of the projecting protrusion of 1.0 mm.
・ Leakage occurred in 10 out of 50 samples 4 with a thickness of 1.5 mm.
As a result, when the projecting length of the projecting protrusion is 1.5 mm, the thickness of the favorable projecting protrusion is 0.3 mm or more and less than 1.5 mm, preferably about 0.5 to 1.3 mm, more preferably It was found to be about 0.5 to 1.0 mm. The leakage in the sample 1 occurs because the elastic force of the elastic protrusion is weak and the pressure for pressing the seal protrusion against the container mouth is weak, and the leakage in the sample 4 is high in the rigidity of the elastic protrusion. This is due to incomplete cap mounting.
[0025]
【The invention's effect】
As described above, the synthetic resin cap of the present invention and the closing device using the same are the annular elastic members extending downward to any position from the periphery of the top plate portion of the synthetic resin cap to the upper end portion of the cylindrical portion. From the radially inner side of the projecting projection and the projecting projection, the tip extends toward the inner wall of the tube portion, and at least the tip portion is provided with an annular sealing projection that is flexible and integrally provided with the top plate portion. When the synthetic resin cap is attached to the container mouth, the seal projection is bent in contact with the container mouth, and the elastic projection is pressed radially outward. In a linerless cap that does not apply a liner material, good sealing performance can be obtained, and a low-cost synthetic resin cap can be provided.
In addition, when the synthetic resin cap is attached to the container mouth portion, the container mouth portion is sealed with the sealing projection pressed against the upper end of the container mouth portion by the elastic force of the elastic projection, so that the container mouth portion is securely sealed. be able to. Furthermore, when a bottle mouth falling phenomenon occurs in which the upper end of the container mouth part falls inward in the radial direction, the falling can be compensated by returning the projecting protrusion radially inward, and the bottle mouth falling phenomenon has occurred. Even in this case, the sealability can be maintained, so that the adaptability to the container is excellent.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional front view showing an example of a closing device of the present invention.
FIG. 2 is a cross-sectional view of an essential part showing an initial state of cap screwing of the same closing device.
FIG. 3 is an essential part cross-sectional view showing a state in the middle of screwing the cap.
FIG. 4 is a cross-sectional view of an essential part showing a cap screwing end state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Synthetic resin cap, 2 ... Top plate part, 3 ... Tube part, 4 ... Cap body, 6 ... Bridge, 7 ... Horizontal score, 8 ... Main part, 9 ... TE ring part DESCRIPTION OF SYMBOLS 10 ... Screw part, 11 ... Tab, 12 ... Bullet protrusion, 13 ... Seal protrusion, 21 ... Container, 21A ... Container mouth part, 22 ... Male screw, 23 ... Annular bulge part 24 …… Pressing portion, 25 …… Extension step portion, 26 …… Bridge extending means, 27 …… Storage guide surface.

Claims

A cap body comprising a top plate portion and a cylindrical portion hanging from the periphery thereof, and the cylindrical portion is partitioned by a weakening line into a main portion above the weakening line and a lower tamper evidence ring portion; In the synthetic resin cap provided with a plurality of locking projections that can be raised and lowered on the inner wall surface of the tamper-evidence ring portion, the thread portion is formed on the inner wall surface of the portion,
An annular projecting projection extending downward to any position from the peripheral edge of the top plate portion to the upper end portion of the cylinder portion, and from the radially inner side of the projecting projection, the tip extends toward the inner wall of the cylinder portion, An annular seal projection having at least a tip portion having flexibility is provided integrally with the top plate portion,
When the synthetic resin cap is attached to the container mouth, the seal protrusion abuts against the container mouth and bends, and the elastic protrusion is pressed radially outward to bend and deform elastically. Characteristic synthetic resin cap.

A cap body comprising a top plate portion and a cylindrical portion hanging from the periphery thereof is divided into a main portion above the weakening line and a lower tamper evidence ring portion by a weakening line capable of cutting the cylindrical portion. A synthetic resin cap provided with a threaded portion formed on the inner wall surface of the main portion and provided with a plurality of undulating locking projections protruding from the inner wall surface of the tamper-evidence ring portion; A closing device comprising a container in which a male screw is formed and an annular bulge is formed below the male screw,
The synthetic resin cap has an annular elastic projection extending downward to any position from the peripheral edge of the top plate portion to the upper end portion of the cylindrical portion, and the tip of the cylindrical protrusion from the radially inner side of the elastic protrusion An annular seal projection that extends toward the inner wall and at least the tip portion is flexible is provided integrally with the top plate portion,
When the synthetic resin cap is attached to the container mouth, the seal protrusion is bent in contact with the container mouth, and the elastic protrusion is pressed radially outward to bend and deform elastically . A closing device characterized by that.

The synthetic resin cap is provided with a plate-like undulating tab as a locking projection, and the container opens the synthetic resin cap attached to the container mouth to the bulging portion A push-down portion having an inclined surface that gradually bulges downward toward the cap opening direction is formed, which is engaged with the tab of the cap and pushes down the tab when rotated in the direction. Item 3. The closing device according to Item 2.

The closing device according to claim 3, wherein the pressing portion is provided with an extended step portion that engages with the tab pressed down by the inclined surface and prevents the tab from moving upward.

The closing device according to claim 3 or 4, wherein an opposite side of the inclined surface of the extended step portion is a storage guide surface that gradually reduces the protruding height in the cap opening direction.

6. The bridge cutting angle, which is a rotation angle to a position at which the bridge is cut by rotating the cap attached to the container mouth in the opening direction, is 90 degrees or less. The closing device according to claim 1.