JP2004224896A

JP2004224896A - Vinylidene chloride copolymer resin composition and film

Info

Publication number: JP2004224896A
Application number: JP2003013903A
Authority: JP
Inventors: Tomohiko Honda; 智彦本田; Kenji Yoshida; 謙次吉田
Original assignee: Asahi Kasei Life and Living Corp
Current assignee: Asahi Kasei Corp
Priority date: 2003-01-22
Filing date: 2003-01-22
Publication date: 2004-08-12
Anticipated expiration: 2023-01-22
Also published as: JP4180391B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vinylidene chloride copolymer resin composition with gummy waste occurrence suppressed during melt extrusion, and to provide a vinylidene chloride copolymer resin film excellent in sealing capability upon high frequency application. <P>SOLUTION: In this vinylidene chloride copolymer resin composition, the vinylidene chloride copolymer contains 70-99 mass% of vinylidene chloride. Each 100 pts. by mass of the resin composition, comprising a vinylidene chloride copolymer having an 80,000-150,000 weight-average molecular weight as determined by gel permeation chromatography, contains 0.01-0.5 pts. by mass of a fluorine process assistant and 0.01-10 pts. by mass of a crystallization enhancer. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、魚肉又は畜肉ソーセージ等の加工食品の包装用フィルムとして、押出加工性及び高周波シール性に優れた塩化ビニリデン系共重合体樹脂フィルムおよび樹脂組成物に関する。
【０００２】
【従来の技術】
塩化ビニリデン系共重合体は、溶融押出成形により、ラップ、フィルム等に成形される。その際、長時間の押出成形によりダイスの樹脂吐出部に汚れ（一般的に目ヤニと言われる）が付着し、経時とともに成長する。ある程度目ヤニが成長すると成形品の表面荒れを引き起こし製品の外観を損ない、更に脱落した目ヤニが成形品に付着することにより、後の延伸工程等においてフィルム破れを引き起こし連続生産が不可能になる事態が発生していた。
【０００３】
目ヤニは、溶融した樹脂がダイス壁面に付着滞留し熱劣化することにより発生することから、従来から塩化ビニリデン系共重合体の押出成形時の目ヤニ発生を抑制する方法として金属剥離性を向上する種々の改良が試みられていた。例えば、塩化ビニリデン系共重合体にアクリル系樹脂を添加（特開平１０−１０１８８４号公報）、塩化ビニリデン系共重合体にシリコーン系加工助剤を添加（特表２００１−５２１９６７号公報）等が知られている。しかしながら、昨今、押出生産性の向上等で該樹脂の加工条件が更に苛酷になってきており、従来の塩化ビニリデン系共重合体樹脂組成物では十分に満足できるものとは言えず、更なる改善が求められていた。
【０００４】
また、オレフィン系樹脂等において、フッ素系加工助剤を添加する方法も知られており（米国特許第３，１２５，５４７号公報、米国特許第４，９０４，７３５号公報、国際公開９５／２１８８７号パンフレット）、スクリュー，ダイスの金属表面にフッ素系樹脂の被膜を形成させることで樹脂の滞留を防止し目ヤニの発生等を抑制、押出加工性を改善することが提案されている。
一方、塩化ビニリデン系フィルムは、自動充填機にて高周波シールにより筒状に成形され、ソーセージ用途として広く利用されている。しかし、塩化ビニリデン系共重合体フィルムにフッ素系加工助剤が添加されていると一旦溶融されたシール部分の強度が出ず、レトルト殺菌の際シール部のパンクが多発する問題があった。
【０００５】
【特許文献１】
特開平１０−１０１８８４号公報
【特許文献２】
特表２００１−５２１９６７号公報
【特許文献３】
米国特許第３，１２５，５４７号公報
【特許文献４】
米国特許第４，９０４，７３５号公報
【特許文献５】
国際公開９５／２１８８７号パンフレット
【０００６】
【発明が解決しようとする課題】
本発明は、従来に比べて、溶融押出時の目ヤニの発生が抑制された塩化ビニリデン系共重合体樹脂組成物、および高周波シール性に優れた塩化ビニリデン系共重合体樹脂フィルムを提供することを目的とする。
【０００７】
【課題を解決するための手段】
本発明者等は、前記従来技術の問題点を克服するために、従来公知の加工助剤及び、それら加工助剤を添加したフィルムのシール性の改良に関して、鋭意検討を行った結果、塩化ビニリデン系共重合体樹脂組成物にフッ素系加工助剤及び結晶化速度促進剤を特定の割合で配合することにより上記問題を解決した。即ち本発明は、下記の通りである。
【０００８】
１．塩化ビニリデン系共重合体の塩化ビニリデン含有率が７０質量％以上９９質量％以下であって、ゲルパーミエーションクロマトグラフィー法による重量平均分子量が８万以上１５万以下である塩化ビニリデン系共重合体からなる樹脂組成物１００質量部に対し、０．０１質量部以上０．５質量部以下のフッ素系加工助剤、及び０．０１質量部以上１０質量部以下の結晶化速度促進剤を含有することを特徴とする塩化ビニリデン系共重合体樹脂組成物。
【０００９】
２．フッ素系加工助剤が、フッ素を含有するホモポリマー、およびまたは共重合体ポリマーを含有することを特徴とする１．に記載の塩化ビニリデン系共重合体樹脂組成物。
３．結晶化速度促進剤が、炭酸カルシウム，二酸化珪素、含水珪酸マグネシウム、酸化マグネシウム、水酸化マグネシウム、ゲルパーミエーションクロマトグラフィー法による重量平均分子量が７万以下の塩化ビニリデン系共重合体、および高密度ポリエチレンからなる群から選ばれた少なくとも１種からなることを特徴とする３．いずれかの樹脂組成物から得られる単層フィルム。
４．前記１．〜３．いずれかの樹脂組成物から得られる単層フィルム。
【００１０】
【発明の実施の形態】
以下、本発明について、特にその好ましい形態について詳述する。
本発明に用いる塩化ビニリデン系共重合体は、塩化ビニリデン及び塩化ビニリデンと共重合可能な単量体１種以上からなる共重合体で、塩化ビニリデン７０質量％以上９９質量％以下及び塩化ビニリデンと共重合可能な単量体１種以上１質量％以上３０質量％以下からなる共重合体である。塩化ビニリデンと共重合可能な単量体としては、共重合性に富む物であれば何でも良いが、産業上有用なものとして例えば、塩化ビニル、アクリロニトリル、アクリル酸、メタクリル酸、アルキル基の炭素数が１〜１８のアクリル酸アルキルエステル、アルキル基の炭素数が１〜１８のメタクリル酸アルキルエステル、無水マレイン酸、マレイン酸、マレイン酸アルキルエステル、イタコン酸、イタコン酸アルキルエステル、酢酸ビニル、エチレン、プロピレン、イソブチレン、ブタジエン等の不飽和単量体を挙げることができる。中でも塩化ビニル、アクリル酸メチル、メタアクリル酸ブチルが好んで用いられる。
【００１１】
本発明に用いる塩化ビニリデン系共重合体は、ゲルパーミエーションクロマトグラフィー法による重量平均分子量が８万以上１５万以下であるものが好ましく、分子量が８万未満のものでは押出成形されたフィルムの強度が低すぎ、分子量が１５万を超えるものでは溶融粘度が高く、押出成形時に熱分解しやすい問題がある。
【００１２】
本発明に使用するフッ素系加工助剤の配合割合は、塩化ビニリデン系共重合体樹脂組成物１００質量部に対して０．０１質量部以上０．５質量部以下、好ましくは、０．０５質量部以上０．２質量部以下である。この配合割合が少なすぎると押出成形時の目ヤニ抑制効果が小さく、逆に多すぎると押出成形されたフィルムの透明性が損なわれ、商品価値を落とすことになりやすい。フッ素系加工助剤は、フッ化ビニリデンとヘキサフロロプロピレンの共重合体，ポリテトラフロロエチレン，フッ化ビニリデンとペンタフロロプロピレン共重合体，フッ化ビニリデンとトリフロロ塩化エチレン共重合体，フッ化ビニリデンとヘキサフロロプロピレンとテトラフロロエチレンの共重合体等が知られており、特にフッ化ビニリデンとヘキサフロロプロピレンの共重合体，ポリテトラフロロエチレンが含まれているのが好ましく、その他相溶化剤や安定剤が含まれていてもよい。市販されているものでは、例えば「カイナー」（商品名：アトフィナ社製），「バイトンフリーフロー」（商品名：デュポンダウエラストマー社製），「ダイナマー」（商品名：住友スリーエム社製）などがある。
【００１３】
また、本発明に使用される結晶化速度促進剤は、結晶核剤となって結晶化を促進するものであり、例えば炭酸カルシウム，二酸化珪素、含水珪酸マグネシウム、酸化マグネシウム、水酸化マグネシウム、ゲルパーミエーションクロマトグラフィー法による重量平均分子量が７万以下の塩化ビニリデン系共重合体、高密度ポリエチレンからなる群から選ばれた少なくとも１種からなるものがあげられ、その配合割合は、塩化ビニリデン系共重合体樹脂組成物１００質量部に対し、０．０１質量部以上１０質量部以下、好ましくは０．０２質量部以上０．２質量部以下である。この配合の割合が少なすぎると結晶化速度を促進する効果が少なく、逆に多すぎると押出成形時にダイス表面に形成されたフッ素系加工助剤による被膜を破壊しやすく、目ヤニの抑制効果を打ち消しやすい。
【００１４】
本発明の塩化ビニリデン系共重合樹脂組成物は、押出成形上必要に応じて、その他各種添加剤を加えることも可能である。その他の各種添加剤としては、液状可塑剤、例えば、アセチルクエン酸トリブチル、セバシン酸ジブチル、エポキシ系安定剤（例えばエポキシ化アマニ油、エポキシ化大豆油、エポキシ化ステアリン酸オクチル）、各種着色剤、各種滑剤等を挙げることができる。
本発明による塩化ビニリデン系共重合樹脂組成物は、公知の成形手段、例えば、インフレーション法、Ｔダイ法等の押出成形法、射出成形法、ブロー成形法により、ラップ、フィルム、シート等に成形することができる。
また、本発明の組成物は共押出やラミネートなどの方法により多層フィルムや多層シートに成形することもできる。
【００１５】
【実施例】
以下、実施例により本発明を具体的に説明するが、本発明はこれらに限定されるものではない。
（重量平均分子量の測定方法）
重量平均分子量はＧＰＣシステム（島津製作所製）を用いて測定した。ＴＨＦ（テトラヒドロフラン）を展開溶媒とし、ポリマーのＴＨＦ溶液を４０℃で恒温のＧＰＣ用カラム内を通して示差屈折計で溶出時間を測定した。ＧＰＣカラム校正用標準試料であるポリスチレンを用い重量平均分子量を求めた。
【００１６】
（ダイ汚れの評価）
押出用ダイスを先端に取り付けた口径３０ｍｍ、シリンダー長さと口径の比率が２２の押出機に各組成物を供給した。連続で８時間の運転を行い、目ヤニの付着状態を観察した。目ヤニは下記４段階で評価した。
◎・・・目ヤニは発生しない
○・・・目ヤニの発生は極めて少ない
△・・・目ヤニが発生する
×・・・目ヤニが激しく発生する
【００１７】
（延伸フィルムの作製）
押出用ダイスを先端に取り付けた口径９０ｍｍ、シリンダー長さと口径の比率が２４の押出機に各組成物を供給し、管状に押出した。この管状体を過冷却後、インフレーション２軸延伸法で流れ方向に４倍、巾方向に４倍の延伸を行って管状フィルムとした。この管状フィルムを折り畳んで巻取り、目標厚み４０μｍ巾約１ｍの平坦長尺状のダブルプライフィルムを作製した。
【００１８】
（レトルトパンクの測定方法）
上記平坦長尺状のダブルプライフィルムを巻き取ったものから、フィルムを巻きほどきながら巾８ｃｍに細断して再度巻取り原反を作った。この原反を使用し、旭化成（株）製自動充填包装機ＡＤＰにて高周波シールにより筒状に成形されたものに畜肉，ラード，水の混練物を充填し、レトルト用包装体とした。これを１２０℃、２０分（圧力０．２５ＭＰａ）加熱した。同一の試料フィルムにつき１０００本の包装体をテストし、破裂数からパンク率を算出した。パンクの評価は下記４段階で評価した。
◎・・・パンクが１本も発生しない
○・・・パンクが１〜３本発生する
△・・・パンクが４〜１０本発生する
×・・・パンクが１１〜１０００本発生する
【００１９】
（結晶化速度の測定方法）
結晶化速度は示差走査熱量計（ＤＳＣ−５０型：島津製作所製）を用いて測定した。延伸成膜したフィルム約５ｍｇを窒素雰囲気下、５０℃から１８０℃まで５℃毎分で昇温、１８０℃昇温後、５℃毎分で降温して、１８０℃から発熱ピークが発生するまでの時間により求めた。
【００２０】
（実施例１）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部、フッ化ビニリデン系加工助剤として、フッ化ビニリデン−ヘキサフロロプロピレン共重合体とポリテトラフロロエチレンの混合物（以下、フッ化ビニリデン系加工助剤Ａという）０．０５質量部、含水珪酸マグネシウム０．０３質量部をヘンシェルブレンダーで７分間混合分散した組成物を得た。その組成物を口径３０ｍｍの押出機に連続供給し、目ヤニの観察を８時間実施した。また、その組成物を口径９０ｍｍの押出機にて溶融押出し、作製したフィルムのレトルト時のパンク率を測定した。
【００２１】
（実施例２）
実施例１の組成物のフッ化ビニリデン系加工助剤添加量を０．０７質量部に変更した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２２】
（実施例３）
実施例１の組成物のフッ化ビニリデン系加工助剤添加量を０．１０質量部に変更した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２３】
（比較例１）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部をヘンシェルブレンダーで７分間混合分散した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２４】
（比較例２）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部、フッ化ビニリデン系加工助剤Ａ０．１０質量部をヘンシェルブレンダーで７分間混合分散した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２５】
（比較例３）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部、含水珪酸マグネシウム０．０３質量部をヘンシェルブレンダーで７分間混合分散した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２６】
（比較例４）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部、ＢＡ／ＭＭＡ／ＢＭＡ加工助剤０．５質量部（三菱レイヨン社製、商品名「Ｌ−１０００」）をヘンシェルブレンダーで７分間混合分散した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２７】
（比較例５）
塩化ビニリデン−塩化ビニル共重合体（重量平均分子量１１．５万、塩化ビニリデン含有量が８８質量％、塩化ビニル含有量が１２質量％）１００質量部に、熱安定剤としてエポキシ化アマニ油（ＥＬＯ）２．０質量部、シリコーン系加工助剤０．１３質量部（ダウコーニング社製、商品名「ＭＢ５０−３１４」）をヘンシェルブレンダーで７分間混合分散した組成物を用い、目ヤニの評価及びレトルト時のパンク率の評価を実施した。
【００２８】
上記実施例および比較例の結果を表１に示す。
表１の結果からも明らかなように、フッ化ビニリデン系加工助剤を添加することで目ヤニの発生を抑制することが出来たが、それだけでは結晶化速度が低下することで、レトルト時のパンク率が上昇した。含水珪酸マグネシウムを併せて添加することで結晶化速度が促進されレトルト時のパンク率が減少できた。
【００２９】
【表１】

【００３０】
【発明の効果】
本発明組成物により、従来に比べて、溶融押出時の目ヤニの発生が抑制された。また、この塩化ビニリデン系共重合体樹脂組成物から得られるフィルムは、高周波シール性に優れている。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vinylidene chloride-based copolymer resin film and a resin composition having excellent extrudability and high-frequency sealing properties as a packaging film for processed food such as fish meat or animal meat sausage.
[0002]
[Prior art]
The vinylidene chloride-based copolymer is formed into a wrap, a film, or the like by melt extrusion. At that time, dirt (generally referred to as eye repellent) adheres to the resin discharge portion of the die due to long-time extrusion molding, and grows over time. If eye stains grow to some extent, surface roughness of the molded product is caused and the appearance of the product is impaired, and the dropped eye stains adhere to the molded product, causing film breakage in the subsequent stretching step etc., making continuous production impossible. Things were happening.
[0003]
Since the molten resin is generated when the molten resin adheres to the die wall and accumulates on the die wall and is thermally degraded, the metal peeling property has been improved as a method to suppress the generation of the molten resin during extrusion molding of vinylidene chloride copolymer. Various improvements have been attempted. For example, it is known that an acrylic resin is added to a vinylidene chloride-based copolymer (Japanese Patent Application Laid-Open No. 10-101883), and a silicone-based processing aid is added to a vinylidene chloride-based copolymer (Japanese Patent Application Laid-Open No. 2001-521967). Have been. However, in recent years, the processing conditions of the resin have become more severe due to the improvement in extrusion productivity and the like, and the conventional vinylidene chloride-based copolymer resin composition cannot be said to be sufficiently satisfactory. Was required.
[0004]
In addition, a method of adding a fluorine-based processing aid to an olefin-based resin or the like is also known (US Pat. No. 3,125,547, US Pat. No. 4,904,735, WO 95/21887). Pamphlet), it has been proposed to form a coating of a fluororesin on the metal surface of a screw or a die to prevent the resin from staying, to suppress the occurrence of die buildup, etc., and to improve the extrudability.
On the other hand, a vinylidene chloride-based film is formed into a tubular shape by high-frequency sealing with an automatic filling machine, and is widely used for sausage applications. However, if a fluorine-based processing aid is added to the vinylidene chloride-based copolymer film, the strength of the once-sealed seal portion does not come out, and there is a problem that puncturing of the seal portion frequently occurs during retort sterilization.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 10-101883 [Patent Document 2]
JP-T-2001-521967 [Patent Document 3]
U.S. Pat. No. 3,125,547 [Patent Document 4]
U.S. Pat. No. 4,904,735 [Patent Document 5]
WO95 / 21887 pamphlet [0006]
[Problems to be solved by the invention]
The present invention is to provide a vinylidene chloride-based copolymer resin composition in which the occurrence of eye burrs during melt extrusion is suppressed, and a vinylidene chloride-based copolymer resin film excellent in high-frequency sealing properties, as compared with the conventional art. With the goal.
[0007]
[Means for Solving the Problems]
The present inventors have conducted intensive studies on conventionally known processing aids and on improving the sealing properties of films to which these processing aids have been added in order to overcome the above-mentioned problems of the prior art. The above problem has been solved by blending a fluorine-based processing aid and a crystallization rate accelerator in a specific ratio into the system copolymer resin composition. That is, the present invention is as follows.
[0008]
1. A vinylidene chloride copolymer having a vinylidene chloride content of 70% by mass or more and 99% by mass or less and a weight average molecular weight by gel permeation chromatography of 80,000 or more and 150,000 or less from a vinylidene chloride-based copolymer 100 parts by mass of the resulting resin composition, contains 0.01 to 0.5 parts by mass of a fluorine-based processing aid, and 0.01 to 10 parts by mass of a crystallization rate accelerator. A vinylidene chloride copolymer resin composition comprising:
[0009]
2. The fluorine-based processing aid contains a fluorine-containing homopolymer and / or a copolymer polymer. 4. The vinylidene chloride-based copolymer resin composition described in 1. above.
3. The crystallization rate promoting agent is calcium carbonate, silicon dioxide, hydrous magnesium silicate, magnesium oxide, magnesium hydroxide, a vinylidene chloride copolymer having a weight average molecular weight of 70,000 or less by gel permeation chromatography, and high-density polyethylene. 2. At least one member selected from the group consisting of A single-layer film obtained from any of the resin compositions.
4. 1. ~ 3. A single-layer film obtained from any of the resin compositions.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with respect to particularly preferred embodiments.
The vinylidene chloride copolymer used in the present invention is a copolymer comprising vinylidene chloride and at least one monomer copolymerizable with vinylidene chloride, and is copolymerized with vinylidene chloride in an amount of 70% by mass to 99% by mass and with vinylidene chloride. It is a copolymer consisting of one or more polymerizable monomers and 1 to 30% by mass. As the monomer copolymerizable with vinylidene chloride, any substance having a high copolymerizability may be used, but as industrially useful monomers, for example, vinyl chloride, acrylonitrile, acrylic acid, methacrylic acid, carbon number of alkyl group Are 1 to 18 acrylic acid alkyl ester, alkyl group having 1 to 18 carbon atoms, methacrylic acid alkyl ester, maleic anhydride, maleic acid, maleic acid alkyl ester, itaconic acid, itaconic acid alkyl ester, vinyl acetate, ethylene, Examples include unsaturated monomers such as propylene, isobutylene, and butadiene. Among them, vinyl chloride, methyl acrylate and butyl methacrylate are preferably used.
[0011]
The vinylidene chloride copolymer used in the present invention preferably has a weight average molecular weight of not less than 80,000 and not more than 150,000 by gel permeation chromatography, and if the molecular weight is less than 80,000, the strength of the extruded film is preferable. However, when the molecular weight is too low and the molecular weight exceeds 150,000, the melt viscosity is high and there is a problem that it is easily decomposed during extrusion molding.
[0012]
The blending ratio of the fluorine-based processing aid used in the present invention is 0.01 to 0.5 parts by mass, preferably 0.05 parts by mass, based on 100 parts by mass of the vinylidene chloride-based copolymer resin composition. To 0.2 parts by mass. If the compounding ratio is too small, the effect of suppressing eye drop at the time of extrusion molding is small, and if it is too large, the transparency of the extruded film is impaired and the commercial value tends to be reduced. Fluorine-based processing aids include copolymers of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, vinylidene fluoride and pentafluoropropylene copolymer, vinylidene fluoride and trifluoroethylene chloride copolymer, and vinylidene fluoride. Copolymers of hexafluoropropylene and tetrafluoroethylene, etc. are known, and particularly preferred are copolymers of vinylidene fluoride and hexafluoropropylene, preferably containing polytetrafluoroethylene, and other compatibilizers and stabilizers. An agent may be included. Examples of commercially available products include "Kynar" (trade name: manufactured by Atofina), "Viton Free Flow" (trade name: manufactured by Dupont Dow Elastomer), and "Dynamer" (trade name: manufactured by Sumitomo 3M). is there.
[0013]
The crystallization rate promoter used in the present invention serves as a nucleating agent to promote crystallization. Examples thereof include calcium carbonate, silicon dioxide, hydrous magnesium silicate, magnesium oxide, magnesium hydroxide, and gel permeation. And at least one selected from the group consisting of vinylidene chloride copolymers having a weight average molecular weight of 70,000 or less by high density chromatography and high-density polyethylene. It is 0.01 to 10 parts by mass, preferably 0.02 to 0.2 parts by mass, based on 100 parts by mass of the united resin composition. If the proportion of this compounding is too small, the effect of accelerating the crystallization rate is small, and if too large, on the other hand, the film formed by the fluorine-based processing aid formed on the die surface during extrusion molding is easily broken, and the effect of suppressing eye tarnish is reduced. Easy to negate.
[0014]
The vinylidene chloride-based copolymer resin composition of the present invention can also contain various other additives as necessary in extrusion molding. Other various additives include liquid plasticizers, for example, tributyl acetylcitrate, dibutyl sebacate, epoxy stabilizers (eg, epoxidized linseed oil, epoxidized soybean oil, epoxidized octyl stearate), various coloring agents, Examples include various lubricants.
The vinylidene chloride copolymer resin composition according to the present invention is formed into wraps, films, sheets, and the like by known molding means, for example, an extrusion molding method such as an inflation method and a T-die method, an injection molding method, and a blow molding method. be able to.
Further, the composition of the present invention can be formed into a multilayer film or a multilayer sheet by a method such as coextrusion or lamination.
[0015]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
(Method of measuring weight average molecular weight)
The weight average molecular weight was measured using a GPC system (manufactured by Shimadzu Corporation). Using THF (tetrahydrofuran) as a developing solvent, a polymer THF solution was passed through a GPC column at a constant temperature of 40 ° C., and the elution time was measured with a differential refractometer. The weight average molecular weight was determined using polystyrene, which is a standard sample for GPC column calibration.
[0016]
(Evaluation of die contamination)
Each composition was supplied to an extruder having a diameter of 30 mm and a ratio of cylinder length to diameter of 22 having an extruding die attached to the tip. The operation was continuously performed for 8 hours, and the adhesion state of the eye repellent was observed. The eye stain was evaluated on the following four levels.
◎ ・・・ Eye cast is not generated ○ ・・・ Eye cast is extremely low △ ・・・ Eye cast is generated × ・・・ Eye cast is generated intensely
(Preparation of stretched film)
Each composition was supplied to an extruder having a diameter of 90 mm and a ratio of cylinder length to diameter of 24 having an extruding die attached to the tip, and extruded into a tube. After supercooling this tubular body, it was stretched 4 times in the flow direction and 4 times in the width direction by an inflation biaxial stretching method to obtain a tubular film. This tubular film was folded and wound up to produce a flat long double-ply film having a target thickness of about 40 μm and a width of about 1 m.
[0018]
(Method of measuring retort puncture)
The flat long double-ply film was wound up, and the film was cut into 8 cm width while being unwound, and a rolled up web was again formed. Using the raw material, kneaded material of meat, lard, and water was filled into a cylinder molded by a high-frequency seal with an automatic filling and packaging machine ADP manufactured by Asahi Kasei Corporation to obtain a retort package. This was heated at 120 ° C. for 20 minutes (pressure 0.25 MPa). 1000 wraps were tested for the same sample film, and the puncture rate was calculated from the number of bursts. The puncture was evaluated on the following four levels.
・・・: No puncture is generated ・・・: 1 to 3 punctures are generated △: 4 to 10 punctures are generated X: 11 to 1000 punctures are generated
(Method of measuring crystallization rate)
The crystallization rate was measured using a differential scanning calorimeter (DSC-50: manufactured by Shimadzu Corporation). Approximately 5 mg of the stretched film is heated in a nitrogen atmosphere from 50 ° C. to 180 ° C. at 5 ° C. every minute, then heated at 180 ° C., and then cooled at 5 ° C. every minute until the exothermic peak occurs from 180 ° C. Time.
[0020]
(Example 1)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer 2.0 parts by mass, 0.05 mass of a mixture of vinylidene fluoride-hexafluoropropylene copolymer and polytetrafluoroethylene (hereinafter referred to as vinylidene fluoride-based processing aid A) as a vinylidene fluoride-based processing aid Parts and 0.03 parts by weight of hydrous magnesium silicate were mixed and dispersed in a Henschel blender for 7 minutes to obtain a composition. The composition was continuously supplied to an extruder having a diameter of 30 mm, and observation of eye drop was performed for 8 hours. The composition was melt-extruded with an extruder having a diameter of 90 mm, and the puncture rate of the produced film during retort was measured.
[0021]
(Example 2)
Using the composition of Example 1 in which the amount of the vinylidene fluoride-based processing aid added was changed to 0.07 parts by mass, the evaluation of eye repellency and the evaluation of the puncture rate during retort were performed.
[0022]
(Example 3)
Using the composition of Example 1 in which the amount of the vinylidene fluoride-based processing aid added was changed to 0.10 parts by mass, the evaluation of eye drop and the evaluation of the puncture rate during retort were performed.
[0023]
(Comparative Example 1)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer ) Using a composition obtained by mixing and dispersing 2.0 parts by mass with a Henschel blender for 7 minutes, evaluation of eye repellency and evaluation of a puncture rate at the time of retort were performed.
[0024]
(Comparative Example 2)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer Using a composition obtained by mixing and dispersing 2.0 parts by mass and 0.10 parts by mass of a vinylidene fluoride-based processing aid A with a Henschel blender for 7 minutes, the evaluation of the eye drop and the evaluation of the puncture rate during retort were performed.
[0025]
(Comparative Example 3)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer 2.) A composition prepared by mixing and dispersing 2.0 parts by mass and 0.03 parts by mass of hydrous magnesium silicate with a Henschel blender for 7 minutes was used to evaluate the tarnish and the puncture rate during retort.
[0026]
(Comparative Example 4)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer ) 2.0 parts by mass and 0.5 parts by mass of BA / MMA / BMA processing aid (trade name “L-1000” manufactured by Mitsubishi Rayon Co., Ltd.) were mixed and dispersed in a Henschel blender for 7 minutes. Was evaluated and the puncture rate during retort was evaluated.
[0027]
(Comparative Example 5)
100 parts by mass of a vinylidene chloride-vinyl chloride copolymer (weight average molecular weight: 115,000, vinylidene chloride content: 88% by mass, vinyl chloride content: 12% by mass), and epoxidized linseed oil (ELO) as a heat stabilizer Using a composition obtained by mixing and dispersing 2.0 parts by mass and 0.13 parts by mass of a silicone-based processing aid (trade name “MB50-314”, manufactured by Dow Corning Co., Ltd.) for 7 minutes with a Henschel blender, to evaluate the eye drop and The evaluation of the puncture rate during retort was performed.
[0028]
Table 1 shows the results of the above Examples and Comparative Examples.
As is evident from the results in Table 1, the addition of a vinylidene fluoride-based processing aid was able to suppress the generation of eye spots. The puncture rate has risen. By adding hydrous magnesium silicate together, the crystallization rate was promoted and the puncture rate during retort could be reduced.
[0029]
[Table 1]

[0030]
【The invention's effect】
According to the composition of the present invention, generation of eye repelling during melt extrusion was suppressed as compared with the conventional composition. The film obtained from the vinylidene chloride-based copolymer resin composition has excellent high-frequency sealing properties.

Claims

A vinylidene chloride copolymer having a vinylidene chloride content of 70% by mass or more and 99% by mass or less and a weight average molecular weight of 80,000 to 150,000 by gel permeation chromatography is used. 100 parts by mass of the resulting resin composition, contains 0.01 to 0.5 parts by mass of a fluorine-based processing aid, and 0.01 to 10 parts by mass of a crystallization rate accelerator. A vinylidene chloride copolymer resin composition comprising:

The vinylidene chloride-based copolymer resin composition according to claim 1, wherein the fluorine-based processing aid contains a fluorine-containing homopolymer and / or a copolymer polymer.

The crystallization rate promoting agent is calcium carbonate, silicon dioxide, hydrous magnesium silicate, magnesium oxide, magnesium hydroxide, a vinylidene chloride copolymer having a weight average molecular weight of 70,000 or less by gel permeation chromatography, and high-density polyethylene. The vinylidene chloride copolymer resin composition according to claim 1, comprising at least one member selected from the group consisting of:

A single-layer film obtained from the resin composition according to claim 1.