JP3774672B2 - Aliphatic polyester biodegradable resin film molding - Google Patents

Description

【００１６】
（式中、Ｒ³は炭素数１〜１０の二価脂肪族基を表す。）
で表されるものを挙げることができる。
式（６）中、Ｒ³は二価の脂肪族基を示す。二価脂肪族基としては、炭素数４〜１０、好ましくは４〜８の直鎖状又は分岐鎖状のアルキレン基が挙げられる。また、Ｒ³は反応に不活性な置換基、たとえば、アルコキシ基やケト基等を有することができる。また、Ｒ³は酸素やイオウ等のヘテロ原子を主鎖に含有することができ、例えばエーテル結合、チオエーテル結合等で隔てられた構造を含有することもできる。
【００１７】
ラクトン類の具体例としては、例えば、β−プロピオラクトン、β−ブチロラクトン、γ−ブチロラクトン、β−バレロラクトン、δ−バレロラクトン、δ−カプロラクトン、ε−カプロラクトン、４−メチルカプロラクトン、３，５，５−トリメチルカプロラクトン、３，３，５−トリメチルカプロラクトンなどの各種メチル化カプロラクトン；β−メチル−δ−バレロラクトン、エナントラクトン、ラウロラクトン等のヒドロキシカルボン酸の環状１量体エステル；グリコリド、Ｌ−ラクチド、Ｄ−ラクチド等の上記ヒドロキシカルボン酸の環状２量体エステル；その他、１，３−ジオキソラン−４−オン、１，４−ジオキサン−３−オン、１，５−ジオキセパン−２−オン等の環状エステル−エーテル等を挙げることができる。これらは２種以上のモノマーを混合して使用してもよい。
【００１８】
本発明における上記（Ａ）、（Ｂ）及び（Ｃ）の３成分の重縮合反応によって得られる脂肪族ポリエステル共重合体は、ランダムである。上記モノマーの仕込は、一括仕込み（ランダム）である。
【００１９】
本発明における上記（Ａ）、（Ｂ）および（Ｃ）の３成分の重縮合反応によって脂肪族ポリエステル共重合体（ａ）もしくは低分子量の共重合体（Ｄ）を合成する工程（ａ）は、使用する原料の種類によって、例えば、前半の脱水反応が主に進行するエステル化工程と、後半のエステル交換反応が主に進行する重縮合工程とに分けることもできる。
エステル化工程は８０℃〜２５０℃、好ましくは１００℃〜２４０℃、さらに好ましくは１４５℃〜２３０℃の反応温度で、０．５〜５時間、好ましくは１〜４時間、７６０〜１００Ｔｏｒｒの条件下で行うことが望ましい。触媒は、必ずしも必要としないが、原料として用いられる脂肪族ジカルボン酸又はジエステル１モルに対して、１０^-7〜１０^-3モル、好ましくは１０^-6〜５×１０^-4モルの量で用いてもよい。
後半の重縮合工程は、反応系を減圧しながら反応温度を高めて２〜１０時間、好ましくは３〜６時間で終了することが望ましく、最終的には１８０℃〜２７０℃、好ましくは１９０℃〜２４０℃の反応温度で減圧度３Ｔｏｒｒ以下、好ましくは１Ｔｏｒｒ以下とすることが望ましい。この工程では、一般的なエステル交換反応触媒を用いる方が好ましく、原料として用いられる脂肪族ジカルボン酸又はジエステル１モルに対して、１０^-7〜１０^-3モル、好ましくは１０^-6〜５×１０^-4モルの量で用いる。この範囲より触媒量が少なくなると反応がうまく進行せず、反応に長時間を要するようになる。一方、この範囲より多くなると重合時のポリマーの熱分解、架橋、着色等の原因となり、また、ポリマーの成形加工において熱分解等の原因となり好ましくない。
【００２０】
工程（ａ）において、脱水反応が主に進行するエステル化工程と、後半のエステル交換反応が主に進行する重縮合工程との両者において用いることのできる触媒としては、以下のような具体例を挙げることができるが、これらの触媒は単独で用いても、２種以上組合せて用いてもよい。
触媒としては、金属類の各種化合物、例えば、カルボン酸塩、炭酸塩、ホウ酸塩、酸化物、水酸化物、水素化合物、アルコラート、アセチルアセトネートキレート等が挙げられる。上記金属類としては、リチウム、カリウムなどのアルカリ金属；マグネシウム、カルシウム、バリウムなどのアルカリ土類金属；スズ、アンチモン、ゲルマニウム等の典型金属；鉛、亜鉛、カドニウム、マンガン、コバルト、ニッケル、ジルコニウム、チタン、鉄等の遷移金属；ビスマス、ニオブ、ランタン、サマリウム、ユウロピウム、エルビウム、イッテルビウム等のランタノイド金属等が挙げられる。
【００２１】
触媒としては、また、含窒素塩基性化合物や、ホウ酸、またはホウ酸エステルなども用いられる。
具体的には、アルカリ金属化合物としては、水酸化ナトリウム、水酸化カリウム、水酸化リチウム、炭酸水素カリウム、炭酸水素リチウム、炭酸ナトリウム、炭酸カリウム、炭酸リチウム、酢酸ナトリウム、酢酸カリウム、酢酸リチウム、ステアリン酸ナトリウム、ステアリン酸リチウム、水素化ホウ素ナトリウム、フェニル化ホウ素ナトリウム、安息香酸リチウム、リン酸二水素ナトリウム、リン酸二水素カリウム、リン酸二水素リチウムなどが挙げられる。
【００２２】
アルカリ土類金属化合物としては、水酸化カルシウム、水酸化バリウム、水酸化マグネシウム、水酸化ストロンチウム、炭酸水素カルシウム、炭酸水素バリウム、炭酸水素マグネシウム、炭酸水素ストロンチウム、炭酸カルシウム、炭酸バリウム、炭酸マグネシウム、炭酸ストロンチウム、酢酸カルシウム、酢酸バリウム、酢酸マグネシウム、酢酸ストロンチウム、ステアリン酸カルシウム、ステアリン酸バリウム、ステアリン酸マグネシウム、ステアリン酸ストロンチウムなどが挙げられる。
【００２３】
典型金属化合物としては、ジブチルスズヒドロキシド、ジブチルスズジラウレート、三酸化アンチモン、酸化ゲルマニウム、炭酸ビスマスヒドロキシド、酢酸ビスマスヒドロキシドなどが挙げられる。
遷移金属化合物としては、酢酸鉛、酢酸亜鉛、アセチルアセトネート亜鉛、酢酸カドニウム、酢酸マンガン、マンガンアセチルアセトネート、酢酸コバルト、コバルトアセチルアセトネート、酢酸ニッケル、ニッケルアセチルアセトネート、酢酸ジルコニウム、ジルコニウムアセチルアセトネート、酢酸チタン、テトラブトキシチタネート、テトライソプロポキシチタネート、チタニウムヒドロキシアセチルアセトネート、酢酸鉄、アセチルアセトネート鉄、酢酸ニオブなどが挙げられる。
希土類化合物としては、酢酸ランタン、酢酸サマリウム、酢酸ユウロピウム、酢酸エルビウム、酢酸イッテルビウムなどが挙げられる。
【００２４】
含窒素塩基性化合物としては、具体的には、テトラエチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシド、テトラブチルアンモニウムヒドロキシド、トリメチルベンジルアンモニウムヒドロキシドなどの脂肪族アミンや芳香族アミンから誘導された有機アンモニウムヒドロキシド類；トリメチルアミン、トリエチルアミン、ジメチルベンジルアミン、トリフェニルアミンなどの三級アミン類；Ｒ₂ＮＨ（式中Ｒはメチル、エチルなどのアルキル、フェニル、トルイルなどのアリール基などである）示される二級アミン類、ＲＮＨ₂（式中Ｒは上記と同じである）で示される一級アミン類；アンモニア、テトラメチルアンモニウムボロハイドライド、テトラブチルアンモニウムボロハイドライド、テトラブチルアンモニウムテトラフェニルボレート、テトラメチルアンモニウムテトラフェニルボレートなどの塩基性化合物などが挙げられる。これらの内、テトラアルキルアンモニウムヒドロキシド類が特に好ましい。
ホウ酸エステルとしては、具体的には、ホウ酸トリメチル、ホウ酸トリヘキシル、ホウ酸トリヘプチル、ホウ酸トリフェニル、ホウ酸トリトリル、ホウ酸トリナフチルなどが挙げられる。
【００２５】
脂肪族ポリエステル共重合体（ａ）もしくは低分子量脂肪族ポリエステル共重合体（Ｄ）を合成する工程（ａ）において、原料（Ａ）成分および（Ｂ）成分の仕込み比は、以下の条件式（８）に合致するように選択することが望ましい。
１．０≦［Ｂ］／［Ａ］≦２．０ （８）
（式中、［Ａ］は（Ａ）成分のモル数、［Ｂ］は（Ｂ）成分のモル数を表す。）
［Ｂ］／［Ａ］の値が１より小さいと、過剰の酸の存在によって加水分解反応が進行し、所望の分子量の脂肪族ポリエステル共重合体（Ｄ）を得ることが難しく、また［Ｂ］／［Ａ］の値が２より大きい場合は前半のエステル化工程終了時点での分子量が過度に小さく、後半の重縮合工程に長時間の反応時間が必要となる。
【００２６】
本発明では、最終的に実用的な強度を有する脂肪族ポリエステル共重合体を得るために、溶融状態の低分子量脂肪族ポリエステル共重合体（Ｄ）に前記式（７）で表される２官能性の連結剤（Ｅ）を加えて重量平均分子量を４０，０００以上に高めてもよい。特開平４−１８９８２２号及び特開平４−１８９８２３号公報によれば、脂肪族ジカルボン酸又はその誘導体と脂肪族ジオールから低分子量脂肪族ポリエステルを合成し、これにジイソシアネート化合物を加えて分子量を増加させる方法が開示されているが、本発明のような、脂肪族ジカルボン酸、その無水物、又はそのエステル体（Ａ）、脂肪族ジオール（Ｂ）、及びヒドロキシカルボン酸もしくはヒドロキシカルボン酸エステル又はラクトン類（Ｃ）の３成分を原料とする系に適用した例は無い。
【００２７】
重合工程（ａ）で得られる低分子量脂肪族ポリエステル共重合体（Ｄ）は、重量平均分子量が５，０００以上、好ましくは１０，０００以上であり、酸価と水酸基価の値の合計が１．０から４５の間であり、さらに酸価が３０以下であることが望ましい。
共重合体（Ｄ）の酸価と水酸基価の値の合計は、共重合体（Ｄ）の末端基の濃度に比例しており、分子量は重量平均分子量が５，０００以上の場合、実質上酸価と水酸基価の値の合計は４５以下である。酸価と水酸基価の値の合計が４５より大きい場合、共重合体（Ｄ）の分子量が低く、連結剤の添加によって所望の分子量まで高めようとするのに、多量の連結剤が必要となる。連結剤の使用量が多い場合には、ゲル化などの問題が生じやすい。酸価と水酸基価の値の合計が１．０以下の場合には、該共重合体（Ｄ）の分子量が高いために溶融状態の粘度が高くなる。この場合は、連結剤の使用量も極少量となるために均一に反応させることが困難で、やはりゲル化などの問題が生じやすい。また、均一に反応させることを目的として溶融温度を上げるとポリマーの熱分解、架橋、着色等の問題が生じる。
【００２８】
本発明に用いる連結剤（Ｅ）は前記式（７）によって表される。連結剤（Ｅ）の反応基Ｘ¹、及びＸ²としては、実質上水酸基とのみ反応して共有結合を形成可能な式（９）〜（１１）：
【００２９】
【化２】

【００３０】
で表される反応基群及び／又は、実質上カルボキシル基とのみ反応して共有結合を形成可能な一般式（１２）〜（１５）
【００３１】
【化３】

【００３２】
（Ｒ⁸〜Ｒ¹⁰は２価の脂肪族基または芳香族基を表し、環に直接結合している水素は脂肪族及び／又は芳香族基で置換されてもよい。）
で表される３〜８員環の環状反応基群から選ぶことができる。Ｘ¹とＸ²は同一でも異なってもよい。
【００３３】
前記式（９）で表されるイソシアネート基が導入された連結剤（Ｅ）の具体例としては、一連のジイソシアネート化合物を挙げることができる。具体的には、トリレンジイソシアネート、キシレンジイソシアネート、ジフェニルメタンジイソシアネート、ナフチレンジイソシアネート、ヘキサメチレンジイソシアネート、水添ジフェニルメタンジイソシアネート、リジンジイソシアネート、トリフェニルメタンジイソシアネート、トランス−シクロヘキシレン１，４−ジイソシアネート、ｐ−フェニレンジイソシアネート、イソホロンジイソシアネート等のジイソシアネート化合物、及びそれらのアロファネート変性体、ビュレット変性体、イソシアヌレート変性体、ポリオール変性体もしくはポリチオールとのアダクト変性体等が挙げられる。特に好ましいジイソシアネート化合物としては、キシレンジイソシアネート、イソホロンジイソシアネート、ヘキサメチレンジイソシアネート等の無黄変型イソシアネート化合物を挙げることができる。このようなジイソシアネート化合物は、単独で使用しても、２種以上併用してもよい。
【００３４】
前記式（１０）で表されるイソチオシアネート基が導入された連結剤（Ｅ）の具体例としては、一連のジイソチオシアネート化合物を挙げることができる。具体的には、ｐ−フェニレンジイソチオシアネート、ヘプタメチレンジイソチオシアネート、４，４’−メチレンジフェニルイソチオシアネート、イソフタロイルイソチオシアネートなどを挙げることができる。このようなジイソチオシアネート化合物は、単独で使用しても、２種以上併用してもよい。
【００３５】
前記式（１１）で表されるエポキシ基が導入された連結剤（Ｅ）の具体例としては、一連のジエポキシ化合物を上げることができる。具体的には、ビスフェノールＡジグリシジルエーテルなどのビスフェノール型エポキシ化合物、フェノールノボラックやクレゾールノボラックなどのノボラック型エポキシ化合物、レゾルシン型エポキシ化合物、ビニルシクロヘキセンジオキシド、ジシクロペンタジエンオキシドなどの脂環化合物、グリシジルエーテル類、ポリエポキシ化ポリブタジエンなどを挙げることができる。このようなジエポキシ化合物は、単独で使用しても、２種以上併用してもよい。
【００３６】
前記式（１２）で表わされる基としては、Ｒ⁸がエチレン基であるオキサゾリンが好ましく、オキサゾリンはカルボン酸にエタノールアミンを反応させる等の手段により生成させ、（７）の連結剤を調製できる。特にビスオキサゾリン化合物が好ましい。ビスオキサゾリン化合物の具体例としては、２，２’−メチレンビス（２−オキサゾリン）、２，２’−エチレンビス（２−オキサゾリン）、２，２’−エチレンビス（４−メチル−２−オキサゾリン）、２，２’−プロピレンビス（２−オキサゾリン）、２，２’−テトラメチレンビス（２−オキサゾリン）、２，２’−ヘキサメチレンビス（２−オキサゾリン）、２，２’−オクタメチレンビス（２−オキサゾリン）、２，２’−ｐ−フェニレンビス（２−オキサゾリン）、２，２’−ｐ−フェニレンビス（４−メチル−２−オキサゾリン）、２，２’−ｐ−フェニレンビス（４，−ジメチル−２−オキサゾリン）、２，２’−ｐ−フェニレンビス（４−フェニル−２−オキサゾリン）、２，２’−ｍ−フェニレンビス（２−オキサゾリン）、２，２’−ｍ−フェニレンビス（４−メチル−２−オキサゾリン）、２，２’−ｍ−フェニレンビス（４，４−ジメチル−２−オキサゾリン）、２，２’−ｍ−フェニレンビス（４−フェニル−２−オキサゾリン）、２，２’−ｏ−フェニレンビス（２−オキサゾリン）、２，２’−フェニルビス（４−メチル−２−オキサゾリン）、２，２’−ビス（２−オキサゾリン）、２，２’−ビス（４−メチル−２−オキサゾリン）、２，２’−ビス（４−エチル−２−オキサゾリン）、２，２’−ビス（４−フェニル−２−オキサゾリン）等を挙げることができる。このようなビスオキサゾリン化合物は、単独で使用しても、２種以上併用してもよい。これらのビスオキサゾリン化合物の内、好ましいものは芳香環基を含むもの、更に好ましくはフェニレン基を含むものである。特に好ましくは２，２’−ｍ−フェニレンビス（２−オキサゾリン）及び２，２’−ｐ−フェニレンビス（２−オキサゾリン）である。
【００３７】
式（１３）で表わされる基としては、Ｒ⁹がメチレンであるオキサゾロンやエチレンであるオキサジノンが好ましい。これらの基はＮ−アシル−α又はβ−アミノカルボン酸を、例えば無水酢酸等で脱水することにより容易に調製出来る。式（１３）の基が導入されたビスオキサゾロン化合物は以下の例が挙げられる。２，２’−ビス（５（４Ｈ）−オキサゾロン）、２，２’−メチレンビス（５（４Ｈ）−オキサゾロン）、２，２’−エチレンビス（５（４Ｈ）−オキサゾロン）、２，２’−テトラメチレンビス（５（４Ｈ）−オキサゾロン）、２，２’−ヘキサメチレンビス（５（４Ｈ）−オキサゾロン）、２，２’−デカメチレンビス（５（４Ｈ）−オキサゾロン）、２，２’−ｐ−フェニレンビス（５（４Ｈ）−オキサゾロン）、２，２’−ｍ−フェニレンビス（５（４Ｈ）−オキサゾロン）、２，２’−ナフタレンビス（５（４Ｈ）−オキサゾロン）、２，２’−ジフェニレンビス（５（４Ｈ）−オキサゾロン）、２，２’−（１，４−シクロヘキシレン）−ビス（５（４Ｈ）−オキサゾロン）、２，２’−ビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−メチレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−エチレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−テトラメチレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ヘキサメチレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−デカメチレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ｐ−フェレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ｍ−フェニレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ナフタレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ジフェニレンビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−（１，４−シクロヘキシレン）−ビス（４−メチル−５（４Ｈ）−オキサゾロン）、２，２’−ビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−メチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−エチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−テトラメチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ヘキサメチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−オクタメチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−デカメチレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ｐ−フェニレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ｍ−フェニレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ナフタレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ジフェニレンビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−（１，４−シクロヘキシレン）−ビス（４，４−ジメチル−５（４Ｈ）−オキサゾロン）、２，２’−ビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−メチレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−エチレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−テトラメチレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−ヘキサメチレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−ｐ−フェニレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−ｍ−フェニレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−ナフタレンビス（４−イソプロピル−５（４Ｈ）−オキサゾロン）、２，２’−ビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−メチレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−エチレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−テトラメチレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−ヘキサメチレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−ｐ−フェニレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−ｍ−フェニレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）、２，２’−ナフタレンビス（４−イソブチル−５（４Ｈ）−オキサゾロン）等である。
【００３８】
式（１３）で表される基が導入されたもう一方の代表的化合物であるビスオキサジノン化合物は以下の例が挙げられる。２，２’−ビス（３，１−ベンゾオキサジン−４−オン）、２，２’−メチレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−エチレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−テトラメチレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−ヘキサメチレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−デカメチレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−ｐ−フェニレンビス（３，１−ベンゾオキサジン−４−オン）、２，２′−ｍ−フェニレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−ナフタレンビス（３，１−ベンゾオキサジン−４−オン）、２，２’−（４，４′−ジフェニレン）ビス（３，１−ベンゾオキサジン−４−オン）、２，２’−（１，４−シクロヘキシレン）ビス（３，１−ベンゾオキサジン−４−オン）、２，２’−ビス（４，４−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−メチレンビス（４，５−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−エチレンビス（４，５−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−テトラメチレンビス（４，５−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｐ−フェニレンビス（４，５−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｍ−フェニレンビス（４，５−ジヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ビス（４−メチル−５−ヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−エチレンビス（４−メチル−５−ヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｏ−フェニレンビス（４−メチル−５−ヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｍ−フェニレン（４−メチル−５−ヒドロ−１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｐ−フェニレンビス（４−ヒドロ−５−メチル１，３，６Ｈ−オキサジン−６−オン）、２，２’−ｍ−フェニレンビス（４−ヒドロ−５−メチル−１，３，６Ｈ−オキサジン−６−オン）等である。
【００３９】
式（１４）で表わされるアジリジン基としては、エチレンイミンを酸クロライドや前記ジイソシアナート化合物と反応させることにより容易に生成出来る。
式（１５）で表わされるラクタム基としては、Ｒ¹⁰がトリメチレンであるピロリドン、テトラメチレンであるピペリドン、ペンタメチレンであるカプロタクタムが好ましく、式（１４）と同様にラクタム類を酸クロライドやイソシアナート化合物と反応させることにより容易に生成出来る。
これらの反応に用いられる酸クロライドとしては、例えばテレフタル酸、イソフタル酸、ナフタレンジカルボン酸、アジピン酸、セバシン酸、トリメリット酸、コハク酸等の誘導体である。
【００４０】
連結剤（Ｅ）の反応基Ｘ¹とＸ²を、実質上水酸基とのみ反応して共有結合を形成可能な前記式（９）〜（１１）で表される反応基群から選ぶ場合、前駆体となる低分子量脂肪族ポリエステル共重合体（Ｄ）の酸価は２．０以下、好ましくは１．０以下である。酸価が２．０より大きい場合は、共重合体（Ｄ）の水酸基末端濃度が小さく、連結反応が効率的に行えなかったり、連結反応後、すなわち最終生成物の酸価が大きく、成形加工時の分子量低下が起こり易いなどの問題が生じる。
連結剤（Ｅ）の反応基Ｘ¹とＸ²を、実質上カルボキシル基とのみ反応して共有結合を形成可能な前記式（１２）〜（１５）で表される３〜８員環の環状反応基群から選ぶ場合、共重合体（Ｄ）の酸価は０．５以上３０以下であることが好ましい。酸価が０．５より小さい場合は、連結剤の使用量も極少量となるために均一に反応させることが困難となる。酸価が３０より大きいと、最終生成物の酸価を低くすることが出来なかったり、多量の連結剤を用いてゲル化が生じる危険があるなどの問題が生じる。
【００４１】
連結剤（Ｅ）と共重合体（Ｄ）の反応は、共重合体（Ｄ）が均一な溶融状態又は少量の溶剤を含有した状態で、容易に攪拌可能な条件下で行われることが望ましい。用いる連結剤（Ｅ）の量は、該共重合体（Ｄ）１００重量部に対し、０．１〜５重量部であることが望ましい。これより連結剤（Ｅ）の量が少ないと、所望の分子量の最終生成物を得ることが困難であり、多いと、ゲル化などの問題が生じやすい。
【００４２】
本発明において、原料（Ａ）成分および（Ｃ）成分の仕込み比は以下の条件式（１６）に合致するように選択することが必要である。
０．０２≦［Ｃ］／（［Ａ］＋［Ｃ］）≦０．４０ （１６）
（式中、［Ａ］は（Ａ）成分の使用モル数、［Ｃ］は（Ｃ）成分の使用モル数を示す。）
上記式中の［Ｃ］／（［Ａ］＋［Ｃ］）は、本発明の脂肪族ポリエステル共重合体中に含まれる前記式（２）で表される繰り返し単位Ｑのモル分率（ｑ）を表している。この値が０．０２より小さい場合は、得られるポリマーは結晶性が高く柔軟性のない硬いものとなり、さらに生分解性の点でも速度が遅く不十分のものとなる。また、０．４０より大きい場合は、得られるポリマーの融点が低く、さらに結晶性が極端に低下するために耐熱性が無く実用に不向きである。
【００４３】
本発明の高分子量脂肪族ポリエステル共重合体は、重量平均分子量が４０，０００以上、通常、１００，０００〜３５０，０００、好ましくは７０，０００〜２５０，０００である。また、融点は、通常８０℃以上と高く、しかもその融点と分解温度との差は１００℃以上と大きく、熱成形も容易である。
本発明の脂肪族ポリエステル共重合体において、特に、前記一般式（１）におけるＲ¹およびＲ²が（ＣＨ₂）₂または（ＣＨ₂）₄で、Ｒ³が（ＣＨ₂）₅であるものは、融点が高くかつ結晶性の高いものである。
【００４４】
II.他の生分解性樹脂
本発明は、脂肪族ポリエステル共重合体（ａ）に、更に他の生分解性樹脂（ｂ）を添加することができる。
上記他の生分解性樹脂（ｂ）としては、合成及び／又は天然高分子が使用される。
合成高分子としては、脂肪族ポリエステル、ポリアミド、ポリアミドエステル、生分解性セルロースエステル、ポリペプチド、ポリビニルアルコール、又はこれらの混合物が挙げられる。
中でも、脂肪族ポリエステル、生分解性セルロースエステル、ポリペプチド、ポリビニルアルコールが好ましい。
【００４５】
上記合成脂肪族ポリエステル樹脂としては、縮合重合系で得られた脂肪族ポリエステル樹脂や開環重合で得られたラクトン系樹脂などが挙げられる。以下、合成脂肪族ポリエステル樹脂を、単に、脂肪族ポリエステル樹脂と略称し、天然に産出されるものの場合にはその旨明記する。
脂肪族ポリエステル樹脂としては、ポリラクトン、ポリ乳酸、ポリエチレンサクシネート、ポリブチレンサクシネート等の生分解性のポリエステル樹脂（このような樹脂としては、昭和高分子株式会社のビオノーレに代表される低分子量脂肪族ジカルボン酸と低分子量脂肪族ジオールより合成されるポリエステル樹脂を例示することができる）、特開平９−２３５３６０号、同９−２３３９５６号各公報記載の三元共重合体の脂肪族ポリエステル、特開平７−１７７８２６号公報記載の乳酸とヒドロキシカルボン酸共重合体等が挙げられる。
【００４６】
生分解性セルロースエステルとしては、酢酸セルロース、セルロースブチレート、セルロースプロピオネート等の有機酸エステル；硝酸セルロース、硫酸セルロース、リン酸セルロース等の無機酸エステル；セルロースアセテートブチレート、セルロースアセテートフタレート、硝酸酢酸セルロース等の混成エステルが例示できる。これらのセルロースエステルは、単独で又は二種以上混合して使用できる。これらのセルロースエステルの内、有機酸エステル、特に酢酸セルロースが好ましい。
また、ポリペプチドとしては、ポリメチルグルタミン酸等のポリアミノ酸及びポリアミドエステル等が例示できる。
ポリアミドエステルとしては、ε−カプロラクトンとε−カプロラクタムより合成される樹脂等が挙げられる。
合成高分子としては、例えば脂肪族ポリエステル樹脂を例にすると、ＧＰＣによる標準ポリスチレン換算で数平均分子量が２０，０００以上２００，０００以下、好ましくは４０，０００以上のものが使用できる。
【００４７】
天然高分子としては、澱粉、セルロース、紙、パルプ、綿、麻、毛、絹、皮革、カラギーナン、キチン・キトサン質、天然直鎖状ポリエステル系樹脂、又はこれらの混合物が挙げられる。
上記澱粉としては、生澱粉、加工澱粉及びこれらの混合物が挙げられる。
生澱粉としてはトウモロコシ澱粉、馬鈴箸澱粉、甘藷澱粉、コムギ澱粉、キャッサバ澱粉、サゴ澱粉、タピオカ澱粉、コメ澱粉、マメ澱粉、クズ澱粉、ワラビ澱粉、ハス澱粉、ヒシ澱粉等が挙げられ、加工澱粉としては、物理的変性澱粉（α−澱粉、分別アミロース、湿熱処理澱粉等）、酵素変性澱粉（加水分解デキストリン、酵素分解デキストリン、アミロース等）、化学分解変性澱粉（酸処理澱粉、次亜塩素酸酸化澱粉、ジアルデヒド澱粉等）、化学変性澱粉誘導体（エステル化澱粉、エーテル化澱粉、カチオン化澱粉、架橋澱粉等）などが挙げられる。
【００４８】
上記の中、エステル化澱粉としては、酢酸エステル化澱粉、コハク酸エステル化澱粉、硝酸エステル化澱粉、リン酸エステル化澱粉、尿素リン酸エステル化澱粉、キサントゲン酸エステル化澱粉、アセト酢酸エステル化澱粉など；エーテル化澱粉としては、アリルエーテル化澱粉、メチルエーテル化澱粉、カルボキシメチルエーテル化澱粉、ヒドロキシエチルエーテル化澱粉、ヒドロキシプロピルエーテル化澱粉など；カチオン化澱粉としては、澱粉と２−ジエチルアミノエチルクロライドの反応物、澱粉と２，３−エポキシプロピルトリメチルアンモニウムクロライドの反応物など；架橋澱粉としては、ホルムアルデヒド架橋澱粉、エピクロルヒドリン架橋澱粉、リン酸架橋澱粉、アクロレイン架橋澱粉などが挙げられる。
他の生分解性樹脂（ｂ）の添加量は、脂肪族ポリエステル共重合体（ａ）１００重量部に対して、０．５〜７０重量部、好ましくは５〜６０重量部が適当である。他の生分解性樹脂（ｂ）の添加量が、７０重量部を超えれば本発明の脂肪族ポリエステル共重合体の優れた効果が小さくなり過ぎて好ましくなく、また、０．５重量部未満では、実質的に未添加と同等の物性になり、コンパウンドに要するコストだけがかかることになって好ましくない。
特に、ポリ乳酸（ＰＬＡ）の場合は、生分解速度を制御する目的で使用されるが、本発明のポリエステルブレンド樹脂組成物における脂肪族ポリエステル共重合体とポリ乳酸との重量比は９９．９／０．１〜７０／３０であり、好ましくは、９９．９／０．１〜８０／２０、さらに好ましくは９９．９／０．１〜８５／１５である。ポリ乳酸の量が０．１より少なすぎるとポリ乳酸を配合した生分解遅延効果が認められず、３０より多すぎると本発明のポリエステル系共重合体の特徴であるポリエチレンに近い力学特性が損なわれる。これらは、とりわけ農業用フィルムに適した生分解速度の制御が可能となる。
【００４９】
III.その他の添加剤
本発明の脂肪族ポリエステル系生分解性樹脂を成形してなるフィルム状成形物には、上記他の生分解性樹脂（ｂ）の他、必要に応じてその他の各種樹脂添加剤（ｃ）を添加することができる。
【００５０】
可塑剤としては、脂肪族二塩基酸エステル、フタル酸エステル、ヒドロキシ多価カルボン酸エステル、ポリエステル系可塑剤、脂肪酸エステル、エポキシ系可塑剤、又はこれらの混合物が例示される。
具体的には、フタル酸ジ−２−エチルヘキシル（ＤＯＰ）、フタル酸ジブチル（ＤＢＰ）、フタル酸ジイソデシル（ＤＩＤＰ）等のフタル酸エステル、アジピン酸−ジ−２−エチルヘキシル（ＤＯＡ）、アジピン酸ジイソデシル（ＤＩＤＡ）等のアジピン酸エステル、アゼライン酸−ジ−２−エチルヘキシル（ＤＯＺ）等のアゼライン酸エステル、アセチルクエン酸トリ−２−エチルヘキシル、アセチルクエン酸トリブチル等のヒドロキシ多価カルボン酸エステル、ポリプロピレングリコールアジピン酸エステル等のポリエステル系可塑剤であり、これらは一種または二種以上の混合物で用いられる。
これら可塑剤の添加量としては、フィルムの用途によって異なるが、一般には脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して、３〜３０重量部の範囲が好ましく、特に５〜１５重量部の範囲が好ましい。３重量部未満であると、破断伸びや衝撃強度が低くなり、また３０重量部を超えると、破断強度や衝撃強度の低下を招く場合がある。
【００５１】
本発明で用いる熱安定剤としては、脂肪族カルボン酸塩がある。脂肪族カルボン酸としては、特に脂肪族ヒドロキシカルボン酸が好ましい。脂肪族ヒドロキシカルボン酸としては、乳酸、ヒドロキシ酪酸等の天然に存在するものが好ましい。
塩としては、ナトリウム、カルシウム、アルミニウム、バリウム、マグネシウム、マンガン、鉄、亜鉛、鉛、銀、銅等の塩が挙げられる。これらは、一種または二種以上の混合物として用いることができる。
添加量としては、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して、０．５〜１０重量部の範囲である。上記範囲で熱安定剤を用いると、衝撃強度（アイゾット衝撃値）が向上し、破断伸び、破断強度、衝撃強度のばらつきが小さくなる効果がある。
【００５２】
本発明で用いる滑剤としては、内部滑剤、外部滑剤として一般に用いられるものが使用可能である。たとえば、脂肪酸エステル、炭化水素樹脂、パラフィン、高級脂肪酸、オキシ脂肪酸、脂肪酸アミド、アルキレンビス脂肪酸アミド、脂肪族ケトン、脂肪酸低級アルコールエステル、脂肪酸多価アルコールエステル、脂肪酸ポリグリコールエステル、脂肪族アルコール、多価アルコール、ポリグリコール、ポリクリセロール、金属石鹸、変性シリコーンまたはこれらの混合物が挙げられる。好ましくは、脂肪酸エステル、炭化水素樹脂等が挙げられる。
滑剤を選択する場合には、ラクトン樹脂やその他の生分解性樹脂の融点に応じて、その融点以下の滑剤を選択する必要がある。例えば、脂肪族ポリエステル樹脂の融点を考慮して、脂肪酸アミドとしては１６０℃以下の脂肪酸アミドが選ばれる。
配合量は、フィルムを例にとると、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して、滑剤を０．０５〜５重量部を添加する。０．０５重量部未満であると効果が充分でなく、５重量部を超えるとロールに巻きつかなくなり、物性も低下する。
フィルム用としては、環境汚染を防止する観点から、安全性が高く、且つＦＤＡ（米国食品医薬品局）に登録されているエチレンビスステアリン酸アミド、ステアリン酸アミド、オレイン酸アミド、エルカ酸アミドが好ましい。
【００５３】
光分解促進剤としては、例えば、ベンゾイン類、ベンゾインアルキルエーテル類、ベンゾフェノン、４，４−ビス（ジメチルアミノ）ベンゾフェノンなどのベンゾフェノンとその誘導体；アセトフェノン、α，α−ジエトキシアセトフェノンなどのアセトフェノンとその誘導体；キノン類；チオキサントン類；フタロシアニンなどの光励起材、アナターゼ型酸化チタン、エチレン−ー酸化炭素共重合体、芳香族ケトンと金属塩との増感剤などが例示される。これらの光分解促進剤は、１種又は２種以上併用できる。
【００５４】
生分解促進剤には、例えば、オキソ酸（例えば、グリコール酸、乳酸、クエン酸、酒石酸、リンゴ酸などの炭素数２〜６程度のオキソ酸）、飽和ジカルボン酸（例えば、修酸、マロン酸、コハク酸、無水コハク酸、グルタル酸などの炭素数２〜６程度の低級飽和ジカルボン酸など）などの有機酸；これらの有機酸と炭素数１〜４程度のアルコールとの低級アルキルエステルが含まれる。好ましい生分解促進剤には、クエン酸、酒石酸、リンゴ酸などの炭素数２〜６程度の有機酸、及び椰子殻活性炭等が含まれる。これらの生分解促進剤は１種又は２種以上併用できる。
上記光分解促進剤もしくは光分解促進剤の添加量としては、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して、通常０．００１〜５重量部である。
【００５５】
充填剤（増量剤を含む）としては、種々の充填剤、例えば炭酸カルシウム、マイカ、珪酸カルシウム、タルク、微粉末シリカ（無水物）、ホワイトカーボン（含水物）、石綿、陶土（焼成）、麦飯石、各種の酸化チタン、ガラス繊維等の無機添加剤（無機充填剤ともいう。）や、天然素材の粒子等の有機添加剤（有機充填剤ともいう。）を挙げることができる。
無機充填剤としての微粉末シリカは、湿式法でつくられたシリカや、四塩化ケイ素の酸水素焔中での高温加水分解により製造されたシリカでもよいが、粒径が５０ｎｍ以下のものがよい。
【００５６】
有機充填剤としては、直径が５０ミクロン以下の、紙より製造した微粉末粒子が挙げられる。有機添加剤の添加量は無機添加剤の場合と同じである。
増量剤としては、木粉、ガラスバルーン等が挙げられる。増量剤の添加量は無機添加剤の場合と同じである。
本発明で使用する充填剤は好ましくは炭酸カルシウム及び／又はタルクである。
充填剤を添加することにより形状崩壊速度が向上するとともに溶融粘度及び溶融聴力が大きくなるので、溶融成形時のドローダウンが防がれ、真空成形、ブロー成形、インフレーション成形等の成形性が向上する。
【００５７】
充填剤の添加量は、充填剤／脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂の重量比が９０〜５１／１０〜４９、好ましくは９０〜７０／１０〜３０である。
充填剤の量が過大では、樹脂が粉を吹き、過小では成形時にドローダウン、ネッキング、厚みむら、目やに発生が著しい。
本発明では、上記添加物の他、必要に応じて、着色防止剤、酸化防止剤、有機又は無機顔料などを添加することができる。
【００５８】
着色防止剤としては、フェノール系のアデカスタブＡＯ−７０、ホスファイト系のアデカスタブ２１１２（共に旭電化（株）社製）等が挙げられる。
添加比率は、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して、０．０２〜３重量部、好ましくは０．０３〜２重量部である。
酸化防止剤としては、アミン系、フェノール系、リン系、硫黄系等が挙げられ、添加比率は脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂１００重量部に対して０．０２〜３重量部である。
【００５９】
IV.成形加工及び用途
本発明の脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物を成形して各種フィルム状成形品を得ることができる。
成形はペレット等への１次成形、それらをシート、フィルム、テープ（これらは一軸または二軸延伸物を含み、延伸により透明性、機械的強度が向上する。）等への２次成形、さらにフィルムを袋、特に分解性ゴミ袋、水切り袋、シュリンクフィルム（直接製膜してもよい。）、孔あきフィルム、農業用マルチ（防草）フィルム、植生フィルム、ベタ掛けフィルム、根巻きシート、排水シート、養生シート等に；積層フィルムをカード等に、独立気泡緩衝シート、襞付き緩衝材等に加工することができる。
【００６０】
フィルムやシートなどフィルム状成形物の場合には、成形法としてはＴ−ダイ成形、インフレーション成形、カレンダー成形が通常用いられ、また、無延伸でも、一軸もしくは二軸延伸することもできる。
【００６１】
以下に、フィルム、特にインフレーション法によるフィルムを製膜する場合の好適例について説明する。
まず、脂肪族ポリエステル共重合体（ａ）において、ラクトン由来の繰り返し単位（Ｑ）と脂肪族ポリエステル樹脂に由来する繰り返し単位（Ｐ）の比は、前者の７０〜５重量％に対して後者の３０〜９５重量％（両者の合計１００重量％）が好ましいが、この場合前者の上限を６０重量％以下にとることが特に好ましく、前者の４０〜１０重量％に対して後者の６０〜９０重量％の範囲が好適である。
この場合、（Ｑ）が７０重量％を超えるとフィルム等成形物の高温時の機械的物性が低下傾向を示し、５重量％未満では生化学的分解に基づく崩壊性が低下する可能性を有する。この傾向は４０〜１０重量％の範囲から外れた場合も同様のことが言える。
一方、（Ｐ）の量が９５重量％を超えると生分解性が遅くなる傾向にあり、逆に３０重量％未満では、例えばフィルムに加工した場合には耐熱性が低下する可能性がある。この傾向は６０〜９０重量％の範囲から外れた場合も同様のことが言える。
【００６２】
又、滑剤としての脂肪酸アミドの配合割合は、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物１００重量部に対して、０．２〜５重量部が好ましいが、０．３〜１．５重量部の範囲がより好ましい。脂肪酸アミドが０．２重量部未満ではインフレーションフィルムのチューブ内のブロッキングとかフィルムとニップロールやガイドロール間のブロッキング防止効果がやや低くなり、一方、５重量部を超えるとフィルムの滑り性が必要以上に高くなり易く、ロール巻きの崩れ問題の他、印刷適性、接着性等も低下傾向を示し始める。
【００６３】
更に必要に応じて液状滑剤、微粉末シリカ、澱粉等を添加することができる。
液状滑剤の使用目的は、共重合体又は組成物が通常ペレットもしくはビーズ状でインフレーション製膜工程に供給され、これに後記のような嵩比重の極めて小さい微粉末シリカ等を均一に混合しようとする場合と、該ペレットやビーズの表面を可及的ウェットにしておくことが好ましいためである。
【００６４】
このような使用目的を有する液状滑剤の添加量は、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物１００重量部に対して、好ましくは０．１〜３重量部、より好ましくは０．２〜０．７重量部の範囲で添加される。添加量が３重量部を超えると液状滑剤が混合用タンブラーの内面に多量に付着し、べたついて安定な混合が難しくなることがあり、０．１重量部未満ではウェッティング剤としての効果が充分には発揮できないことがある。この傾向は、より好ましい０．２〜０．７重量部の範囲外についても見られる。
一方、ウェッティング剤としての液状滑剤は融点が７０℃以下が好ましく、常温で液状のものがより好ましく使用される。例えば流動パラフイン、パラフィンワックス，ステアリルアルコール，ステアリン酸等の他，ステアリン酸ブチル、ステアリン酸モノグリセリド、ペンタエリスリトールテトラステアレート、ステアリルステアレート等のステアリン酸エステル類などを挙げることができる。
なお、上記液状滑剤中最も好ましい流動パラフインは経口急性毒性（ラット）ＬＤ５０が５ｇ／ｋｇであるので非常に安全であり、食品衛生法の食品添加物として認められていて、フィルムの使用後に廃棄された場合の環境汚染防止の点で非常に好都合の材料である。
【００６５】
上述のごとく滑剤としては液状滑剤を選択したが、若し固体滑剤を使用する場合は、樹脂組成物を含む全体の系が、該固体滑剤の融点以上である必要があり、該融点以下の低温では使用困難である。室温において液体である流動パラフィンはこの点で好ましい滑剤である。
微粉末シリカの使用目的は、本発明に係るインフレーションフィルム及びインフレーション製膜時の前記ブロッキング防止を図ることにある。使用される微粉末シリカは、湿式法でつくられたシリカや、四塩化ケイ素の酸水素焔中での高温加水分解により製造されたシリカ等が充当されるが、特に粒径が５０ｎｍ以下のものが好ましい。
【００６６】
添加方法としては、本発明に係る脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物、又は更に脂肪酸アミドを添加してなる樹脂組成物に加熱混練される方法が最も好ましく、かなりの高い剪断力が作用し二次凝集粒子がほぐされ、フィルム間及びフィルムと各ロール間のブロッキングとかべたつきの防止効果を発揮する。
なお、微粉末シリカの添加量は、脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）の混合物１００重量部に対して、０．１〜３重量部の範囲が上記効果の発揮の点で最も好ましい。
【００６７】
脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物に前記各種添加剤を加えて配合組成物を得る方法としては、従来使用されてきた各種方法が適用でき、特に限定されるものではない。
脂肪族ポリエステル共重合体（ａ）または脂肪族ポリエステル共重合体（ａ）と他の生分解性樹脂（ｂ）からなる脂肪族ポリエステル系生分解性樹脂組成物、その他添加剤（ｃ）の混練方法は、一般的な方法が好ましく使用でき、具体的には原料樹脂ペレットや粉体、固体の細片等をヘンシェルミキサーやリボンミキサーで乾式混合し、単軸や２軸の押出機、バンバリーミキサー、ニーダー、ミキシングロールなどの公知の溶融混合機に供給して溶融混練することができる。
【００６８】
上記用途としては、生分解性を有するため埋め立てなど土壌に廃棄しても環境に何ら問題を与えない点から、特に、フィルム、シート、発泡シート等及びそれらの２次成形体等が好ましく使用することができる。
【００６９】
【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。
実施例中の脂肪族ポリエステル共重合体の種々の測定値は下記の方法により求めた。
（分子量及び分子量分布）
ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法を用いて標準ポリスチレンから校正曲線を作成し、数平均分子量（Ｍｎ）、重量平均分子量（Ｍｗ）及び分子量分布（Ｍｗ／Ｍｎ）を求めた。溶離液にはクロロホルムを用いた。
（酸価と水酸基価）
ＪＩＳ Ｋ００７０に基づいて測定した。
（熱的性質）
示差走査熱量分析装置（ＤＳＣ）により融点及びガラス転移点を求めた。
（機械的強度）
ＪＩＳ Ｋ７１１３に基づき、試験片の引張伸度及び強度を求めた。
【００７０】
（脂肪族ポリエステル共重合体の合成）
[製造実施例１]
攪拌機、分留コンデンサー、温度調節装置を備えた予備重合槽に、１，４−ブタンジオール３６．２５ｋｇ（４０２．２モル）、コハク酸４３．１８ｋｇ（３６５．７モル）、ε−カプロラクトン７．３７ｋｇ（６４．６モル）を一括仕込みした。前記式（８）における［Ｂ］／［Ａ］＝１．１であり、前記式（１６）における［Ｃ］／（［Ａ］＋［Ｃ］）＝０．１５である。
常圧下、１４５〜２２５℃の温度にて攪拌し、エステル化反応を行った。留出液の量が９．８ｋｇを超えたところで予備重合工程を終了し、反応液を本重合槽に移した。さらに本重合槽にチタン酸テトライソプロピルエステル２０．７９ｇを加え、反応液を２１０〜２２０℃の温度に保ちながら攪拌して、最終的に１．０Ｔｏｒｒ（１３３Ｐａ）にまで減圧し、２時間攪拌下に、１，４−ブタンジオールを留出させて、即ち、脱グリコール反応によりエステル交換反応を行った。得られた低分子量ポリエステルの重量平均分子量は５３，０００、酸価は１．６ｍｇ-ＫＯＨ／ｇであった。
脱グリコール反応終了後、得られた低分子量ポリエステルを１９０℃で溶融状態にして、ヘキサメチレンジイソシアネート７７３．７ｋｇを加え、攪拌すると、粘度は急速に増大したがゲル化はしなかった。得られた脂肪族ポリエステル共重合体（Ａ：PCL/PBS=15/85）は、Ｍｗ２０．２万、酸価は１．４ｍｇＫＯＨ／ｇ、融点は１０１℃であった。
機械強度は、引張強度が６００ｋｇｆ／ｃｍ²、引張伸度が７４０％であった。
【００７１】
[製造実施例２]
製造実施例１で使用したものと同じ予備重合槽に、１，４−ブタンジオール２９．８６ｋｇ、コハク酸３８．００ｋｇ、ε−カプロラクトン１２．２４ｋｇを一括仕込みした。常圧下、１４５〜２２５℃の温度にて攪拌し、エステル化反応を行った。留出液の量が１０．４ｋｇを超えたところで予備重合工程を終了し、反応液を本重合槽に移した。さらに本重合槽にチタン酸テトライソプロピルエステル１８．２９ｇを加え、反応液を２１０〜２２０℃の温度に保ち攪拌し、最終的に１．０Ｔｏｒｒ（１３３Ｐａ）にまで減圧し、３時間攪拌して脱グリコール反応（エステル交換反応）を行った。得られた低分子量ポリエステルの重量平均分子量は９３，０００、酸価は４．２ｍｇ-ＫＯＨ／ｇであった。
脱グリコール反応終了後、低分子量ポリエステルを１９０℃で溶融状態にして、２，２’−ｍ−フェニレンビス（２−オキサゾリン）１３５３ｋｇを加え、攪拌すると、粘度は急速に増大したがゲル化はしなかった。得られた脂肪族ポリエステル共重合体（Ｂ：PCL/PBS=25/75）は、Ｍｗ１７．２万、酸価は２．１ｍｇ-ＫＯＨ／ｇ、融点は８８℃であり、フィルム成形可能であった。
機械強度は、引張強度が５３０ｋｇｆ／ｃｍ²、引張伸度が８００％であった。
【００７２】
[製造実施例３]
攪拌機、分留コンデンサー、温度調節装置を備えた予備重合槽に、エチレングリコール（分子量：６２．０７）２．１０ｋｇ（３３．７９モル）、コハク酸（分子量：１１８．０９）３．８０ｋｇ（３２．１８モル）、ε−カプロラクトン（分子量：１１４．１４）０．５０ｋｇ（４．３９モル）およびチタン酸テトライソプロピルエステル４．５７ｇ、リン酸マグネシウム０．９３ｇを一括仕込みした。
常圧下、１４５〜２３５℃の温度にて攪拌し、エステル化反応を行った。留出液の量が１．１５ｋｇを超えたところで予備重合工程を終了し、反応液を本重合槽に移した。反応液を２２０〜２４０℃に保ちながら攪拌して、最終的に０．６Ｔｏｒｒにまで減圧し、攪拌下に９時間エチレングリコールを留出させて、即ち、脱グリコール反応によりエステル交換反応を行った。得られたポリエステルの重量平均分子量は２２１，０００、酸価は０．６０ｍｇ-ＫＯＨ／ｇ、融点は９０℃、Ｔｇは−１３℃であり、ＮＭＲで求めたポリマー中の全ユニット量に対するカプロラクトンユニット量の割合は１０．５ｍｏｌ％であった。
得られたポリマーの機械強度は、引張強度が３８０ｋｇｆ／ｃｍ²、引張伸度が９４０％であり、マルチフィルムに適した力学特性を有していた。また、１００μｍ以下の厚みのフィルムに成形することが可能であった。
【００７３】
[製造実施例４]
攪拌機、分留コンデンサー、温度調節装置を備えた予備重合槽に、１，４−ブタンジオール３６．２５ｋｇ、コハク酸４３．１８ｋｇ、ε−カプロラクトン１０．３２ｋｇを一括仕込みした。ここで前記式（８）における［Ｂ］／［Ａ］＝１．０９であり、前記式（１６）における［Ｃ］／（［Ａ］＋［Ｃ］）＝０．２０である。さらにチタン酸テトライソプロピルエステル５２．０１ｇ、および第二リン酸マグネシウム三水和物１０．４６ｇを加え、常圧下、１４５〜２２５℃の温度にて攪拌し、エステル化反応を行った。留出液の量が１０．０ｋｇを超えたところで予備重合工程を終了し、反応液を本重合槽に移した。反応液をほぼ２３０℃に保ち攪拌し、最終的に１．０ｍｍＨｇ（１３３Ｐａ）にまで減圧し、４時間攪拌して脱グリコール反応（エステル交換反応）を行った。得られた低分子量ポリエステル（Ｄ）の重量平均分子量は５６，０００、酸価は１．６ｍｇＫＯＨ／ｇであった。
脱グリコール反応終了後、ポリエステル（Ｄ）の１９０℃における溶融状態で、ヘキサメチレンジイソシアネート６００ｇを加え、攪拌すると、粘度は急速に増大したがゲル化はしなかった。得られた本発明の高分子量脂肪族ポリエステル共重合体は、Ｍｗ１８．２万、酸価は１．６ｍｇＫＯＨ／ｇであった。ＤＳＣでは製造実施例１と同様に単一の融解ピークが現れ、融点は９６℃であり、フィルム成形可能であった。
フィルムの機械的強度は、引張強度が３１０ｋｇｆ／ｃｍ²、引張伸度が６６０％であった。
【００７４】
（他の生分解性樹脂）
実施例及び比較例で使用した他の生分解性樹脂の略号を下記に示す。
#1001：Bionolle#1001（脂肪族ジカルボン酸−脂肪族ジオール系、昭和高分子(株)製）
#3001：Bionolle#3001（脂肪族ジカルボン酸−脂肪族ジオール系、昭和高分子(株)製）
PH7：セルグリーンPH7（ポリカプロラクトン系、ダイセル化学工業（株）製）
【００７５】
（実施例１〜４，参考例１〜２）
製造実施例４で製造した脂肪族ポリエステル系共重合体とポリ乳酸とを下記表１示す重量比で溶融混練し、得られたポリエステルブレンド樹脂組成物を厚さ２０μｍのインフレーションフィルムに成形した。このフィルムをカットして縦１５ｃｍ×横１０ｃｍの孔の開いた非生分解性の型枠に貼り付けた。市販の園芸用土と腐葉土とを１：１の重量比で混合し、最大容水量の５０％となるよう水分を調整した後、作成したサンプルを埋設し、水分量を保持しながら２３℃で２０日間放置した。サンプルを取り出し、フィルム表面を水で洗浄した後、乾燥し、フィルムに開いた孔の面積をTOYOBO製Image Analyzer V10を用いて画像処理し、ボイド面積を算出した。
また、上記と同様にして得たポリエステルブレンド樹脂組成物を、１５０℃で縦５ｃｍ×横５ｃｍ×厚さ６００μｍのプレス片に成形し、上記と同様に調整した土中に埋設し、水分量を保持しながら３０日間放置した。サンプルを取り出し、水で洗浄した後、乾燥し、重量を測定した。埋設前の試料からの重量減少率を表に示した。
参考例として、ポリ乳酸の代りにビオノーレ＃１００１を用い、同様の試験を行った場合の結果を示した。
【００７６】
【表１】

【００７７】
以上より、本発明における脂肪族ポリエステル共重合（ａ）より生分解が遅いビオノーレ＃１００１を混合しても生分解制御の効果はほとんど認められないが、ポリ乳酸を混合すると大幅な生分解制御の効果が認められる。
【００７８】
[実施例５〜９および参考例３〜５]
[コンパウンド]
後記表２に示す処方にブレンドした樹脂を二軸押出機を用いて、コンパウンド化し、ペレット化した。樹脂原料は事前に乾燥(50℃×10時間以上)したものを用いた。またそれぞれのブレンドにはタンブラーを用いた。
【００７９】
[フィルム化]
上記で得られたペレットを使用して、フィルムを得た。
フィルム引取速度：１７．０〜２２．０ｍ／ｍｉｎ
リップ幅：２．０ｍｍ
フィルム幅：１３５０ｍｍ
フィルム厚み：２０μｍ
このようにして得られた樹脂ペレット及びフィルム状成形物を使用し、以下に示す各種評価を行い、その結果を表２に示した。
【００８０】
[手裂性]
現在汎用フィルムとして広く使用されているポリエチレンフィルム(インフレーション成形)に切り込みを入れたものを、手で裂いた時の感覚を基準（１０点満点）とし、上記で得られた各フィルムを手で裂いた時の感覚を１０点満点で評価した。
この場合の判断基準としては手で裂いた時の手に伝わる抵抗や、裂け方（直線性の有無）、裂け面の波打ちなど、単なる強度以外に全体的な引裂き性を官能的に評価した。
【００８１】
官能評価の評価基準は次の通りである。
◎：裂け面が波打ち、また斜めに裂け、引裂抵抗大のもの。
○：裂け面が直線的で、波打ちも少ないが、引裂抵抗大のもの。
×：裂け面が直線的で、引裂抵抗小のもの。
××：×より引裂抵抗小で、裂けが伝播しやすいもの。
【００８２】
[引裂強度]
サンプル：上記で得られた各フィルムを幅５０ｍｍ、長さ（ＭＤ方向）１００ｍｍにカットし、幅の一端に、真中から長さ方向に３０ｍｍの切込みを入れたものを用いた。
サンプルは、２３℃×５０％ＲＨの恒温恒湿機にて２４時間調湿して、測定に供した。
＜引裂強度測定条件＞
サンプル長さ：３０ｍｍ
使用機器：ＯＬＩＥＮＴＥＣ社製、商品名ＲＴＡ−５００
ロードセル：５ｋｇｆ，２０％
クロスヘッドスピード：５００ｍｍ／分
試験回数：ｎ＝３とし、結果をその平均値で示した。
官能評価の評価基準は次の通りである。
◎：引裂強度強く、斜めに裂け、裂け面が波打つもの。
○：引裂強度強く、裂け面が直線的で、裂け面が波打つもの。
×：引裂強度弱く、裂け面が直線的のもの。
××：引裂強度非常に弱く、裂け面が直線的で、裂け面の波打が殆ど無いもの。
【００８３】
［引張試験］
上記で得られた各フィルムを、ＪＩＳ Ｋ−７１１３に基づいて、２号ダンベル片に打抜いたものを用いて引張試験を行なった。なお、フィルムの打抜きは、ＭＤ、ＴＤ両方向について行なった。
サンプルは、２３℃×５０％ＲＨの恒温恒湿機にて２４時間調湿して測定に供した。なお、測定条件は以下の通りである。
＜引張試験測定条件＞
サンプル長さ：４０ｍｍ
使用機器：ＯＬＩＥＮＴＥＣ社製、商品名ＲＴＡ−５００
ロードセル：１０ｋｇｆ、４０％
クロスヘッドスピード：５００ｍｍ／分
試験回数：ｎ＝３とし、結果をその平均値で示した。
【００８４】
［生分解性］
活性汚泥を用いた簡易分解度試験（ＪＩＳ Ｋ−６９５０）に従って生分解性評価を行なった。
姫路市標準活性汚泥を使用し、試験期間２８日後の生分解性（重量％）を測定した。また、上記試験で得られた生分解性の数値が６０％以下のものを×、６０％以上のものを○、８０％以上のものを◎と表示した。
【００８５】
[分解速度]
上記で得られた各フィルムをＪＩＳ Ｋ−７１１３に基づいて、２号ダンベル片に打抜いたものを園芸用土にいれ、２８℃×９９％ＲＨの条件下で６０時間埋設し、埋設前と埋設後のフィルムについて上記引張試験を行い、ＴＤ方向の伸度を比較した。なお、上記埋設後のフィルムを分解速度評価後のフィルムとも言う。
【００８６】
【表２】

【００８７】
参考例３は＃１００１を９０重量％添加した系であるが、柔軟性の乏しい＃１００１を多く含んでいるせいか、成形加工性、フィルム初期物性ともに薄膜のフィルムには適さない結果となった。また生分解性に関しても＃１００１を９０重量％配合すると分解速度が非常に遅く、短期間で使用するマルチフィルム等の用途には適さない結果となった。
【００８８】
また、参考例４と５は＃１００１を８０重量％にまで減少させた系であるが、それでもそのフィルム性能はＭＤ方向の破断伸度、更にはＴＤ方向の破断伸度が十分なものではなく、特にマルチフィルム等の用途として十分なものではなかった。分解速度評価後のＴＤ方向の引張破断伸度保持率は高かったが初期の伸度が不十分であったためこれも実用的なものではなかった。
これに対し、実施例７と８は＃１００１の添加量を３０重量部にした系である。成形加工性も問題なく、かつフィルム成形後の破断伸度、特にＴＤ方向の破断伸度が大きく向上していた。ＴＤ方向の破断伸度が７００％を超えるくらいまで上昇すると実用性が出てくる。このときの分解速度評価後のＴＤ方向の破断伸度も良く保持していた。
実施例６および９は、＃３００１及びＰＨ７成分である柔軟なポリエステルを配合した系であるが、これによりそのＴＤ破断伸度は飛躍的に向上、更に引き裂き強度も飛躍的に向上した。得られたフィルムは、農業用マルチフィルム等の実用物性には十分な数値になっている。また分解速度評価後のＴＤ方向の破断伸度も良く保持していた。
【００８９】
（実施例１０〜１４）
次の表３は、前記製造実施例１で得られた高分子量脂肪族ポリエステル共重合体Ａを用いてリップ幅、ブロー比、押出温度、冷却方法を適用して厚み２０μｍのインフレーションフィルムを製造して各種評価を行った結果を示したものである。
【００９０】
【表３】

【００９１】
以上より、生分解性速度が制御され、かつ実用的な物性をもった生分解性フィルム、特に生分解性農業用マルチフィルムを提供できることが確認された。
【００９２】
【発明の効果】
本発明の脂肪族ポリエステル系生分解性樹脂を成形してなるフィルム状成形物は、工業的に供給可能であって実用性のある物性を有し、特に農業用マルチフィルムは実用的に好適に使用でき有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film-like molded product obtained by molding an aliphatic polyester-based biodegradable resin. More specifically, the present invention can be industrially supplied and has practical physical properties and can be decomposed by microorganisms in soil or water. The present invention relates to a film-like molded product obtained by molding an aliphatic polyester biodegradable resin.
[0002]
[Prior art]
The characteristic of plastic is that it has sufficient strength for practical use but has a low specific gravity and resistance to corrosion. In particular, general-purpose plastics are industrially mass-produced, and at the same time are widely used in daily life and industrial fields, and their usage is remarkably increased. Since many plastics are not decomposed in the natural environment, environmental destruction due to plastic disposal has recently become a problem. Therefore, in recent years, development of plastics that can be biodegraded in the natural environment has been demanded.
Aliphatic polyester is attracting attention as a highly versatile biodegradable resin. Recently, polylactic acid (PLA), polybutylene succinate (PBS), polyethylene succinate (PES), polycaprolactone (PCL), etc. have been put on the market. ing.
One of the uses of these biodegradable aliphatic polyesters is in the field of films for packaging, agriculture, food, etc., where high strength and practical heat resistance and biodegradability control are applied to molded products. Realization at the same time is an important issue.
Among the above aliphatic polyesters, PLA has a high melting point at around 170 ° C. and high heat resistance. However, because of its brittle nature, the strength of the molded product is low, and it does not decompose in the soil and has composting equipment. is necessary. PBS and PES have sufficient heat resistance at a melting point of around 100 ° C., but have a low biodegradation rate, are insufficient in practical use, and lack flexibility in mechanical properties. Although PCL is excellent in flexibility, its application is limited due to its low melting point of 60 ° C. and heat resistance, but its biodegradation rate is very fast.
[0003]
As described above, it is difficult to solve the above problems with homopolymers of aliphatic polyesters. However, the inventors of the present invention have disclosed a polybutylene succinate-polycaprolactone copolymer (PBSC) described in, for example, Japanese Patent No. 2997756. Thus, by introducing a caprolactone unit into the aliphatic polyester copolymer, practical flexibility and moderate biodegradability can be realized, and by controlling the content of the caprolactone unit, It has been found that the above-mentioned problem that can maintain the sufficient heat resistance by setting the melting point to 80 ° C. or more and control the biodegradability can be solved.
[0004]
In this publication, a method based on a direct polycondensation method is disclosed as a method for producing such an aliphatic polyester copolymer, which is a very useful method. In such a method, water produced by a dehydration reaction or a transesterification reaction is used. Since it is necessary to sufficiently remove diol and diol from the reaction system, a long polymerization time may be required to increase the molecular weight. If the molecular weight is low, it is not sufficient for processing as a fiber or film.
Japanese Patent Publication No. 2000-204146 discloses a method in which an acidic phosphorus compound is present from the stage of the prepolycondensation reaction to significantly shorten the polymerization time. There is a risk of increasing the acid value. Japanese Patent No. 3100314 discloses a method of performing a polycondensation reaction at a relatively high temperature such as 240 ° C. as a method for synthesizing an aliphatic polyester homopolymer. However, under high temperature conditions, the molecular weight is likely to decrease due to the thermal decomposition reaction of the polymer. Increasing the amount of the catalyst promotes coloring in addition to the thermal decomposition reaction, and further causes cross-linking of polymer chains. In many cases, the polymer becomes a crosslinked polymer having a large apparent molecular weight and molecular weight distribution, which deteriorates the performance of the polymer.
[0005]
In addition, biodegradable plastics are currently being tested for thin films such as agricultural films, compost bags, and garbage bags, mainly for films.
For example, JP-A-8-259823 discloses a biodegradable mulching material using a biodegradable polymer material, particularly a polymer containing a lactic acid unit. However, the mulching material by this technique is mainly polylactic acid, is too hard as an agricultural mulching material, and its biodegradation rate is too slow, so it is not controlled.
Japanese Patent Application Laid-Open No. 9-111107 discloses a biodegradable plastic film or sheet comprising a polylactic acid polymer and an aliphatic polyester having a glass transition point Tg of 0 ° C. or less, in particular, the content of the biodegradable aliphatic polyester. Discloses a film or sheet for thermoforming in which 7 to 60 parts by weight per 100 parts by weight of the polylactic acid polymer is disclosed. However, this technique is also mainly composed of polylactic acid, and the biodegradation rate is not controlled as described above.
In particular, biodegradable multi-films for agriculture have gradually been recognized for their usefulness in recent years, and the market is also rising accordingly. The performance of biodegradable multi-films for agriculture is for general agriculture using general-purpose plastics such as workability when film is stretched (stretching), moisturizing and warming after spreading, concealment, and crop growth. It is required to balance the performance required for the multifilm with the performance of both the biodegradation rate and biodegradability specific to the biodegradable resin. However, there are few biodegradable agricultural multi-films that are now on the market that satisfactorily satisfy both of these capabilities.
In recent years, there has been a demand for biodegradable agricultural multi-films whose biodegradability rate is controlled and whose physical properties are sufficiently practical.
However, if the film performance as a general plastic is emphasized, the biodegradability is neglected, and if the biodegradability is emphasized, the general performance is neglected. Further studies are needed to fully satisfy both of these performances.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to solve the problems found in the prior art as described above. That is, an object of the present invention is to provide a film-like molded article formed by molding an aliphatic polyester-based biodegradable resin that can be supplied industrially and has practical properties.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a mixture of three components of an aliphatic diol, an aliphatic dicarboxylic acid, and an aliphatic hydroxycarboxylic acid or an anhydrous cyclic compound (lactone) thereof. Molding by using high molecular weight polyester copolymer (a) or aliphatic polyester copolymer (a) having a weight average molecular weight of 40,000 or more synthesized by polycondensation reaction and other biodegradable resin (b) It was found that the molecular weight stability at the time was good and the film formation was good, and the present invention was completed. The high molecular weight aliphatic polyester copolymer used in the present invention may be one having a high molecular weight by a polycondensation reaction, or once a low molecular weight polyester copolymer having a molecular weight of 5,000 or more is synthesized. Further, an aliphatic polyester copolymer having a weight average molecular weight of 40,000 or more increased by adding a binder such as diisocyanate thereto.
[0008]
That is, in the first aspect of the present invention, the molecular chain has the general formula (1):
-(-CO-R ¹ -COO-R ² -O-)-(1)
(Wherein R ¹ Is a divalent aliphatic group having 1 to 12 carbon atoms, R ² Represents a divalent aliphatic group having 2 to 12 carbon atoms. )
A repeating unit (P) represented by:
General formula (2):
-(-CO-R ^Three -O-)-(2)
(Wherein R ^Three Represents a C1-C10 divalent aliphatic group. )
Repeating unit (Q)
An aliphatic polyester copolymer (a) having a weight average molecular weight of 40,000 or more, or an aliphatic polyester comprising the aliphatic polyester copolymer (a) and another biodegradable resin (b) A biodegradable resin film-like molded product obtained by molding a system biodegradable resin composition is provided.
The second of the present invention is a low molecular weight aliphatic polyester copolymer having a weight average molecular weight of 5,000 or more, wherein the aliphatic polyester copolymer (a) is a polymerization intermediate of the aliphatic polyester copolymer (a). (D) 0.1 to 5 parts by weight of general formula (7) with respect to 100 parts by weight:
X ¹ -R ⁷ -X ² (7)
(Where X ¹ , X ² Is a reactive group capable of forming a covalent bond by acting with a hydroxyl group or a carboxyl group, R ⁷ Represents a single bond, an aliphatic group having 1 to 20 carbon atoms or an aromatic group, and X ¹ , X ² May be the same chemical structure or different)
A biodegradable resin film-like molded article according to the first aspect of the present invention, which is linked by a bifunctional coupling agent (E) represented by the formula:
In the third aspect of the present invention, the general formula (1) includes an aliphatic carboxylic acid containing a succinic acid residue and / or an adipic acid residue, and an ethylene glycol residue and / or 1,4-butanediol residue. A biodegradable resin film-like molded article according to the first or second aspect of the present invention, characterized in that it has a structure produced from an aliphatic glycol by a condensation reaction.
In the fourth aspect of the present invention, the general formula (2) is represented by the following formula: ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone, 3,3,5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone The biodegradable resin film-like molded article according to the first or second aspect of the present invention, characterized in that it is at least one residue selected from the group consisting of δ, valerolactone and enanthlactone.
In the fifth aspect of the present invention, the reactive group of the bifunctional linking agent (E) represented by the general formula (7) is an isocyanate group, an isothiocyanate group, an epoxy group, an oxazoline group, an oxazolone group or an oxazinone group, an aziridine group. Or a biodegradable resin film-like molded product according to the second aspect of the present invention, which is a mixed group thereof.
A sixth aspect of the present invention is characterized in that the other biodegradable resin (b) is blended in an amount of 0.5 to 70 parts by weight with respect to 100 parts by weight of the aliphatic polyester copolymer (a). A biodegradable resin film-like molded product according to the first or second aspect of the invention is provided.
According to a seventh aspect of the present invention, there is provided the biodegradable resin film-like molded article according to the first or sixth aspect, wherein the other biodegradable resin is a synthetic and / or natural polymer.
According to an eighth aspect of the present invention, in the biodegradation according to the first or sixth aspect, the synthetic polymer is composed of an aliphatic polyester, a biodegradable cellulose ester, a polypeptide, polyvinyl alcohol, or a mixture thereof. An adhesive resin film-like molded article is provided.
According to a ninth aspect of the present invention, the natural polymer is starch, cellulose, paper, pulp, cotton, hemp, wool, silk, leather, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. The biodegradable resin film-like molded product according to the first or sixth aspect of the present invention is provided.
A tenth aspect of the present invention is the biodegradable resin film according to any one of the first to ninth aspects of the present invention, wherein the biodegradable resin film-like molded product is formed by inflation molding, T-die extrusion molding, or calendar molding. A shaped molding is provided.
The eleventh aspect of the present invention is that the biodegradable resin film-shaped molded product is a non-stretched, uniaxially stretched, or biaxially stretched film, according to any one of the first to tenth aspects of the present invention. Provide moldings.
A twelfth aspect of the present invention provides the biodegradable resin film-shaped molded article according to any one of the first to tenth aspects of the present invention, wherein the biodegradable resin film-shaped molded article is a shrink film.
A thirteenth aspect of the present invention provides the biodegradable resin film-shaped molded article according to any one of the first to tenth aspects of the present invention, wherein the biodegradable resin film-shaped molded article is a laminated film.
A fourteenth aspect of the present invention provides the biodegradable resin film-shaped molded article according to any one of the first to tenth aspects of the present invention, wherein the biodegradable resin film-shaped molded article is an agricultural multi-film.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
I. Aliphatic polyester copolymer
The aliphatic polyester copolymer (a) used in the present invention is composed of the repeating unit (P) represented by the general formula (1) and the repeating unit (Q) represented by the general formula (2). The weight average molecular weight is 40,000 or more, usually 100,000 to 350,000, preferably 70,000 to 250,000.
The aliphatic polyester copolymer (a) used in the present invention has a low molecular weight aliphatic polyester copolymer (D) molecular chain which is a polymerization intermediate of the aliphatic polyester copolymer (a). A low molecular weight aliphatic polyester copolymer having a weight average molecular weight of 5,000 or more and comprising the repeating unit (P) represented by the general formula (1) and the repeating unit (Q) represented by the general formula (2). The polymer (D) is linked to 100 parts by weight of the copolymer (D) with 0.1 to 5 parts by weight of the bifunctional linking agent (E) represented by the general formula (7). The weight average molecular weight is 40,000 or more, usually 100,000 to 350,000, preferably 70,000 to 250,000.
[0010]
Examples of the component (A) that gives an aliphatic dicarboxylic acid residue in the formula (1) include an aliphatic dicarboxylic acid, its anhydride, or its mono- or diester, and the general formula (3):
R ^Four -OCO-R ¹ -COO-R ^Five (3)
(Wherein R ¹ Is a divalent aliphatic group having 1 to 12 carbon atoms, R ^Four And R ^Five Represents a hydrogen atom or an aliphatic or aromatic group having 1 to 6 carbon atoms. )
It is represented by
In formula (1) and formula (3), R ¹ Represents a C1-C12 divalent aliphatic group.
R ¹ The divalent aliphatic group represented by is preferably a chain or cyclic alkylene group of 2 to 8, and — (CH ₂ ) ₂ -,-(CH ₂ ) _Four C2-C6 linear lower alkylene groups, such as-. R ¹ May have a substituent inert to the reaction, such as an alkoxy group or a keto group, and R ¹ Can contain heteroatoms such as oxygen and sulfur in the main chain, and can also contain, for example, a structure separated by an ether bond, a thioether bond or the like.
[0011]
In formula (3), R ^Four And R ^Five Represents a hydrogen atom or an aliphatic or aromatic group having 1 to 6 carbon atoms; ^Four , R ^Five May be the same or different.
R ^Four And R ^Five When is a hydrogen atom, it represents an aliphatic dicarboxylic acid. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, pimelic acid, azelaic acid, decanedicarboxylic acid, sebacic acid, diglycolic acid, ketopimelic acid, malonic acid, methylmalonic acid and the like.
R ^Four And R ^Five Examples of the aliphatic group represented by the formula include a C1-C6, preferably C1-C4 linear or branched alkyl group, and a C5-C12 cycloalkyl group such as a cyclohexyl group. .
R ^Four And R ^Five Examples of the aromatic group represented by are phenyl group and benzyl group.
Above all, R ^Four And R ^Five Is a lower alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms. Examples of such dialkyl esters include dimethyl succinate, diethyl succinate, dimethyl adipate, diethyl adipate, dimethyl pimelate, dimethyl azelate, dimethyl sebacate, diethyl sebacate, dimethyl decanedicarboxylate, diglycolic acid Examples include dimethyl, dimethyl ketopimelate, dimethyl malonate, and dimethyl methylmalonate. These may be used alone or in combination of two or more.
[0012]
Examples of the component (B) that gives the aliphatic diol residue in the formula (1) include aliphatic diols.
The aliphatic diol has the general formula (4):
HO-R ² -OH (4)
(Wherein R ² Represents a divalent aliphatic group having 2 to 12 carbon atoms. )
It is represented by
In formula (1) and formula (4), R ² Represents a divalent aliphatic group. Examples of the divalent aliphatic group include chain or cyclic alkylene groups having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms. Preferred alkylene groups are — (CH ₂ ) ₂ -,-(CH ₂ ) _Four A linear lower alkylene group having 2 to 6 carbon atoms such as-. In addition, the divalent aliphatic group R ² May have a substituent inert to the reaction, such as an alkoxy group or a keto group. R ² Can contain heteroatoms such as oxygen and sulfur in the main chain, and can also contain, for example, a structure separated by an ether bond, a thioether bond or the like. Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 2-methyl-propanediol, 1,4-butanediol, neopentyl glycol, Pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, dodecamethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, molecular weight 1000 or less Polyethylene glycol or the like can be used. These may be used alone or in combination of two or more. Further, a small amount of a trifunctional alcohol such as 1,1,1-tris (hydroxymethyl) propane may be used in combination.
[0013]
Examples of the component (C) that gives an aliphatic hydroxycarboxylic acid residue in the formula (2) include hydroxycarboxylic acids, hydroxycarboxylic acid esters, and lactones.
Hydroxycarboxylic acid or hydroxycarboxylic acid ester is
General formula (5):
R ⁶ OCO-R ^Three -OH (5)
(Wherein R ^Three Is a divalent aliphatic group having 1 to 10 carbon atoms, R ⁶ Represents a hydrogen atom, an aliphatic group having 1 to 6 carbon atoms or an aromatic group. )
It is represented by
In formula (5), R ^Three Represents a divalent aliphatic group. Examples of the divalent aliphatic group include a linear or cyclic alkylene group having 2 to 10 carbon atoms, preferably 2 to 8 carbon atoms, and more preferably a linear alkylene group having 2 to 8 carbon atoms. R ^Three May have a substituent inert to the reaction, such as an alkoxy group or a keto group. R ^Three Can contain heteroatoms such as oxygen and sulfur in the main chain, and can also contain, for example, a structure separated by an ether bond, a thioether bond or the like.
In formula (5), R ⁶ Is hydrogen or an aliphatic or aromatic group. Examples of the aliphatic group include a linear or branched lower alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms such as a cyclohexyl group, and an aromatic group. , Phenyl group, benzyl group and the like.
[0014]
Examples of the hydroxycarboxylic acid include glycolic acid, L-lactic acid, D-lactic acid, D, L-lactic acid, hydroxypivalic acid, hydroxycaproic acid, and hydroxyhexanoic acid.
Examples of the hydroxycarboxylic acid ester include methyl ester and ethyl ester of the above hydroxycarboxylic acid, and acetic acid ester.
As lactones, general formula (6):
[0015]
[Chemical 1]

[0016]
(Wherein R ^Three Represents a C1-C10 divalent aliphatic group. )
Can be mentioned.
In formula (6), R ^Three Represents a divalent aliphatic group. Examples of the divalent aliphatic group include linear or branched alkylene groups having 4 to 10 carbon atoms, preferably 4 to 8 carbon atoms. R ^Three May have a substituent inert to the reaction, such as an alkoxy group or a keto group. R ^Three Can contain heteroatoms such as oxygen and sulfur in the main chain, and can also contain, for example, a structure separated by an ether bond, a thioether bond or the like.
[0017]
Specific examples of lactones include, for example, β-propiolactone, β-butyrolactone, γ-butyrolactone, β-valerolactone, δ-valerolactone, δ-caprolactone, ε-caprolactone, 4-methylcaprolactone, 3, 5 , 5-trimethylcaprolactone, various methylated caprolactones such as 3,3,5-trimethylcaprolactone; cyclic monomeric esters of hydroxycarboxylic acids such as β-methyl-δ-valerolactone, enanthlactone and laurolactone; glycolide, L -Cyclic dimer ester of the above hydroxycarboxylic acid such as lactide, D-lactide, etc .; 1,3-dioxolan-4-one, 1,4-dioxane-3-one, 1,5-dioxepan-2-one And the like, and the like. These may be used by mixing two or more monomers.
[0018]
The aliphatic polyester copolymer obtained by the polycondensation reaction of the three components (A), (B) and (C) in the present invention is random. is there . The above monomers are charged in a batch (random) Is .
[0019]
The step (a) of synthesizing the aliphatic polyester copolymer (a) or the low molecular weight copolymer (D) by the polycondensation reaction of the three components (A), (B) and (C) in the present invention is as follows: Depending on the type of raw material used, for example, it can be divided into an esterification step in which the first half of the dehydration reaction mainly proceeds and a polycondensation step in which the latter half of the transesterification reaction mainly proceeds.
The esterification step is performed at a reaction temperature of 80 ° C. to 250 ° C., preferably 100 ° C. to 240 ° C., more preferably 145 ° C. to 230 ° C., for 0.5 to 5 hours, preferably 1 to 4 hours, 760 to 100 Torr. It is desirable to do below. The catalyst is not necessarily required, but it is 10 per mol of aliphatic dicarboxylic acid or diester used as a raw material. ^-7 -10 ^-3 Moles, preferably 10 ^-6 ~ 5x10 ^-Four Molar amounts may be used.
The latter polycondensation step is desirably completed in 2 to 10 hours, preferably 3 to 6 hours by raising the reaction temperature while reducing the pressure of the reaction system, and finally 180 ° C to 270 ° C, preferably 190 ° C. The degree of vacuum is 3 Torr or less, preferably 1 Torr or less at a reaction temperature of ˜240 ° C. In this step, it is preferable to use a general transesterification catalyst, and 10 mol per 1 mol of the aliphatic dicarboxylic acid or diester used as a raw material. ^-7 -10 ^-3 Moles, preferably 10 ^-6 ~ 5x10 ^-Four Used in molar amounts. When the amount of the catalyst is less than this range, the reaction does not proceed well, and the reaction takes a long time. On the other hand, if it exceeds this range, it causes thermal decomposition, crosslinking, coloring, etc. of the polymer during polymerization, and also causes thermal decomposition in the molding process of the polymer.
[0020]
Examples of the catalyst that can be used in both the esterification step in which the dehydration reaction mainly proceeds in the step (a) and the polycondensation step in which the latter transesterification reaction mainly proceeds include the following specific examples. Although these can be mentioned, these catalysts may be used independently or may be used in combination of 2 or more types.
Examples of the catalyst include various metal compounds such as carboxylate, carbonate, borate, oxide, hydroxide, hydrogen compound, alcoholate, and acetylacetonate chelate. Examples of the metals include alkali metals such as lithium and potassium; alkaline earth metals such as magnesium, calcium and barium; typical metals such as tin, antimony and germanium; lead, zinc, cadmium, manganese, cobalt, nickel, zirconium, Transition metals such as titanium and iron; and lanthanoid metals such as bismuth, niobium, lanthanum, samarium, europium, erbium, and ytterbium.
[0021]
As the catalyst, nitrogen-containing basic compounds, boric acid, boric acid esters, and the like are also used.
Specifically, the alkali metal compound includes sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, stearin. Examples thereof include sodium acid, lithium stearate, sodium borohydride, sodium phenyl borohydride, lithium benzoate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate and the like.
[0022]
Alkaline earth metal compounds include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, carbonate Examples include strontium, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate.
[0023]
Examples of typical metal compounds include dibutyltin hydroxide, dibutyltin dilaurate, antimony trioxide, germanium oxide, bismuth carbonate, bismuth acetate.
Transition metal compounds include lead acetate, zinc acetate, zinc acetylacetonate, cadmium acetate, manganese acetate, manganese acetylacetonate, cobalt acetate, cobalt acetylacetonate, nickel acetate, nickel acetylacetonate, zirconium acetate, zirconium acetylacetate Nate, titanium acetate, tetrabutoxy titanate, tetraisopropoxy titanate, titanium hydroxyacetylacetonate, iron acetate, iron acetylacetonate, niobium acetate and the like.
Examples of rare earth compounds include lanthanum acetate, samarium acetate, europium acetate, erbium acetate, ytterbium acetate, and the like.
[0024]
Specific examples of the nitrogen-containing basic compound include organic ammonium hydroxides derived from aliphatic amines and aromatic amines such as tetraethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Tertiary amines such as trimethylamine, triethylamine, dimethylbenzylamine, triphenylamine; R ₂ NH (wherein R is an alkyl group such as methyl or ethyl, an aryl group such as phenyl or toluyl, etc.) Secondary amines represented by RNH ₂ (Wherein R is the same as above): basic compounds such as ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetramethylammonium tetraphenylborate Etc. Of these, tetraalkylammonium hydroxides are particularly preferred.
Specific examples of the boric acid ester include trimethyl borate, trihexyl borate, triheptyl borate, triphenyl borate, tolyl borate, and trinaphthyl borate.
[0025]
In the step (a) for synthesizing the aliphatic polyester copolymer (a) or the low molecular weight aliphatic polyester copolymer (D), the charging ratio of the raw material (A) component and the component (B) is as follows: It is desirable to select to meet 8).
1.0 ≦ [B] / [A] ≦ 2.0 (8)
(In the formula, [A] represents the number of moles of component (A), and [B] represents the number of moles of component (B).)
When the value of [B] / [A] is less than 1, the hydrolysis reaction proceeds due to the presence of excess acid, and it is difficult to obtain an aliphatic polyester copolymer (D) having a desired molecular weight. ] / [A] larger than 2, the molecular weight at the end of the first esterification step is too small, and a long reaction time is required for the latter polycondensation step.
[0026]
In the present invention, in order to finally obtain an aliphatic polyester copolymer having practical strength, a difunctional compound represented by the above formula (7) is added to the molten low molecular weight aliphatic polyester copolymer (D). The weight average molecular weight may be increased to 40,000 or more by adding a sex linking agent (E). According to JP-A-4-189822 and JP-A-4-189823, a low molecular weight aliphatic polyester is synthesized from an aliphatic dicarboxylic acid or a derivative thereof and an aliphatic diol, and a molecular weight is increased by adding a diisocyanate compound thereto. Although the method is disclosed, the aliphatic dicarboxylic acid, its anhydride, or its ester form (A), the aliphatic diol (B), and the hydroxycarboxylic acid or hydroxycarboxylic acid ester or lactone as in the present invention There is no example applied to the system using the three components (C) as raw materials.
[0027]
The low molecular weight aliphatic polyester copolymer (D) obtained in the polymerization step (a) has a weight average molecular weight of 5,000 or more, preferably 10,000 or more, and the sum of the acid value and the hydroxyl value is 1. It is desirable that the acid value is 30 or less.
The sum of the acid value and the hydroxyl value of the copolymer (D) is proportional to the concentration of the end groups of the copolymer (D), and the molecular weight is substantially when the weight average molecular weight is 5,000 or more. The sum of the acid value and the hydroxyl value is 45 or less. When the sum of the acid value and the hydroxyl value is greater than 45, the copolymer (D) has a low molecular weight, and a large amount of a linking agent is required to increase the molecular weight to a desired level by adding the linking agent. . When the amount of the binder used is large, problems such as gelation are likely to occur. When the sum of the acid value and the hydroxyl value is 1.0 or less, the viscosity of the molten state is increased because the copolymer (D) has a high molecular weight. In this case, the amount of the binder used is extremely small, so that it is difficult to cause a uniform reaction, and problems such as gelation are likely to occur. In addition, when the melting temperature is raised for the purpose of causing a uniform reaction, problems such as polymer thermal decomposition, crosslinking, and coloring occur.
[0028]
The linking agent (E) used in the present invention is represented by the formula (7). Reactive group X of linking agent (E) ¹ And X ² As the formulas (9) to (11), which can substantially react only with a hydroxyl group to form a covalent bond:
[0029]
[Chemical 2]

[0030]
General groups (12) to (15) capable of forming a covalent bond by reacting substantially only with a carboxyl group and / or a carboxyl group.
[0031]
[Chemical 3]

[0032]
(R ⁸ ~ R ^Ten Represents a divalent aliphatic group or an aromatic group, and the hydrogen directly bonded to the ring may be substituted with an aliphatic and / or aromatic group. )
It can be selected from a group of 3 to 8 membered cyclic reactive groups represented by: X ¹ And X ² May be the same or different.
[0033]
Specific examples of the linking agent (E) into which the isocyanate group represented by the formula (9) has been introduced include a series of diisocyanate compounds. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, lysine diisocyanate, triphenylmethane diisocyanate, trans-cyclohexylene 1,4-diisocyanate, p-phenylene diisocyanate And diisocyanate compounds such as isophorone diisocyanate, and allophanate-modified products, burette-modified products, isocyanurate-modified products, polyol-modified products, and adduct-modified products with polythiols. Particularly preferred diisocyanate compounds include non-yellowing isocyanate compounds such as xylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. Such diisocyanate compounds may be used alone or in combination of two or more.
[0034]
Specific examples of the linking agent (E) into which the isothiocyanate group represented by the formula (10) has been introduced include a series of diisothiocyanate compounds. Specific examples include p-phenylene diisothiocyanate, heptamethylene diisothiocyanate, 4,4′-methylenediphenyl isothiocyanate, and isophthaloyl isothiocyanate. Such diisothiocyanate compounds may be used alone or in combination of two or more.
[0035]
As a specific example of the coupling agent (E) into which the epoxy group represented by the formula (11) is introduced, a series of diepoxy compounds can be raised. Specifically, bisphenol type epoxy compounds such as bisphenol A diglycidyl ether, novolak type epoxy compounds such as phenol novolak and cresol novolak, resorcin type epoxy compounds, alicyclic compounds such as vinylcyclohexene dioxide and dicyclopentadiene oxide, glycidyl Examples thereof include ethers and polyepoxidized polybutadiene. Such diepoxy compounds may be used alone or in combination of two or more.
[0036]
Examples of the group represented by the formula (12) include R ⁸ Oxazoline in which is an ethylene group is preferable, and the oxazoline can be produced by means such as reacting carboxylic acid with ethanolamine to prepare the linking agent (7). Bisoxazoline compounds are particularly preferable. Specific examples of the bisoxazoline compound include 2,2′-methylenebis (2-oxazoline), 2,2′-ethylenebis (2-oxazoline), and 2,2′-ethylenebis (4-methyl-2-oxazoline). 2,2′-propylene bis (2-oxazoline), 2,2′-tetramethylene bis (2-oxazoline), 2,2′-hexamethylene bis (2-oxazoline), 2,2′-octamethylene bis (2-oxazoline), 2,2′-p-phenylenebis (2-oxazoline), 2,2′-p-phenylenebis (4-methyl-2-oxazoline), 2,2′-p-phenylenebis ( 4,2-dimethyl-2-oxazoline), 2,2′-p-phenylenebis (4-phenyl-2-oxazoline), 2,2′-m-phenylenebis (2-oxazoline), 2,2′-m -Phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4,4-dimethyl-2-oxazoline), 2,2'-m-phenylenebis (4-phenyl-2-) Oxazoline), 2,2′-o-phenylenebis (2-oxazoline), 2,2′-phenylbis (4-methyl-2-oxazoline), 2,2′-bis (2-oxazoline), 2,2 Examples include '-bis (4-methyl-2-oxazoline), 2,2'-bis (4-ethyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline), and the like. . Such bisoxazoline compounds may be used alone or in combination of two or more. Among these bisoxazoline compounds, preferred are those containing an aromatic ring group, and more preferred are those containing a phenylene group. Particularly preferred are 2,2′-m-phenylenebis (2-oxazoline) and 2,2′-p-phenylenebis (2-oxazoline).
[0037]
As the group represented by the formula (13), R ⁹ Oxazolone in which is methylene and oxazinone in which ethylene is preferred are preferred. These groups can be easily prepared by dehydrating N-acyl-α or β-aminocarboxylic acid with, for example, acetic anhydride. Examples of the bisoxazolone compound into which the group of the formula (13) is introduced include the following examples. 2,2′-bis (5 (4H) -oxazolone), 2,2′-methylenebis (5 (4H) -oxazolone), 2,2′-ethylenebis (5 (4H) -oxazolone), 2,2 ′ -Tetramethylenebis (5 (4H) -oxazolone), 2,2'-hexamethylenebis (5 (4H) -oxazolone), 2,2'-decamethylenebis (5 (4H) -oxazolone), 2,2 '-P-phenylenebis (5 (4H) -oxazolone), 2,2'-m-phenylenebis (5 (4H) -oxazolone), 2,2'-naphthalenebis (5 (4H) -oxazolone), 2 , 2′-diphenylenebis (5 (4H) -oxazolone), 2,2 ′-(1,4-cyclohexylene) -bis (5 (4H) -oxazolone), 2,2′-bis (4-methyl) -5 (4H) -oxazolone), 2,2 ' -Methylenebis (4-methyl-5 (4H) -oxazolone), 2,2'-ethylenebis (4-methyl-5 (4H) -oxazolone), 2,2'-tetramethylenebis (4-methyl-5 ( 4H) -oxazolone), 2,2′-hexamethylenebis (4-methyl-5 (4H) -oxazolone), 2,2′-decamethylenebis (4-methyl-5 (4H) -oxazolone), 2, 2′-p-ferenebis (4-methyl-5 (4H) -oxazolone), 2,2′-m-phenylenebis (4-methyl-5 (4H) -oxazolone), 2,2′-naphthalenebis (4 -Methyl-5 (4H) -oxazolone), 2,2'-diphenylenebis (4-methyl-5 (4H) -oxazolone), 2,2 '-(1,4-cyclohexylene) -bis (4- Methyl-5 (4H) -oxazo ), 2,2′-bis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-methylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′- Ethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-tetramethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-hexamethylenebis (4 , 4-Dimethyl-5 (4H) -oxazolone), 2,2′-octamethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-decamethylenebis (4,4-dimethyl) -5 (4H) -oxazolone), 2,2'-p-phenylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-m-phenylenebis (4,4-dimethyl-5) (4H) -oxazolone), 2,2′-naphtha Bis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-diphenylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2 ′-(1,4-cyclohexene) Silene) -bis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-bis (4-isopropyl-5 (4H) -oxazolone), 2,2'-methylenebis (4-isopropyl-5) (4H) -oxazolone), 2,2′-ethylenebis (4-isopropyl-5 (4H) -oxazolone), 2,2′-tetramethylenebis (4-isopropyl-5 (4H) -oxazolone), 2, 2'-hexamethylenebis (4-isopropyl-5 (4H) -oxazolone), 2,2'-p-phenylenebis (4-isopropyl-5 (4H) -oxazolone), 2,2'-m-phenylenebi (4-isopropyl-5 (4H) -oxazolone), 2,2'-naphthalenebis (4-isopropyl-5 (4H) -oxazolone), 2,2'-bis (4-isobutyl-5 (4H) -oxazolone) ), 2,2′-methylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2′-ethylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2′-tetramethylenebis ( 4-isobutyl-5 (4H) -oxazolone), 2,2′-hexamethylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2′-p-phenylenebis (4-isobutyl-5 (4H ) -Oxazolone), 2,2′-m-phenylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2′-naphthalenebis (4-isobutyl-5 (4H) -oxazolone) ) Etc.
[0038]
Examples of the bisoxazinone compound, which is another representative compound into which the group represented by the formula (13) is introduced, include the following examples. 2,2′-bis (3,1-benzoxazin-4-one), 2,2′-methylenebis (3,1-benzoxazin-4-one), 2,2′-ethylenebis (3,1- Benzoxazin-4-one), 2,2′-tetramethylenebis (3,1-benzoxazin-4-one), 2,2′-hexamethylenebis (3,1-benzoxazin-4-one), 2,2'-decamethylenebis (3,1-benzoxazin-4-one), 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2'-m- Phenylenebis (3,1-benzoxazin-4-one), 2,2′-naphthalenebis (3,1-benzoxazin-4-one), 2,2 ′-(4,4′-diphenylene) bis ( 3,1-benzoxazin-4-one), 2,2 ′-(1,4- Cyclohexylene) bis (3,1-benzoxazin-4-one), 2,2′-bis (4,4-dihydro-1,3,6H-oxazin-6-one), 2,2′-methylenebis ( 4,5-dihydro-1,3,6H-oxazin-6-one), 2,2′-ethylenebis (4,5-dihydro-1,3,6H-oxazin-6-one), 2,2 ′ -Tetramethylenebis (4,5-dihydro-1,3,6H-oxazin-6-one), 2,2'-p-phenylenebis (4,5-dihydro-1,3,6H-oxazine-6- ON), 2,2′-m-phenylenebis (4,5-dihydro-1,3,6H-oxazin-6-one), 2,2′-bis (4-methyl-5-hydro-1,3) , 6H-oxazin-6-one), 2,2′-ethylenebis (4-methyl-5-hydro) 1,3,6H-oxazin-6-one), 2,2'-o-phenylenebis (4-methyl-5-hydro-1,3,6H-oxazin-6-one), 2,2'-m -Phenylene (4-methyl-5-hydro-1,3,6H-oxazin-6-one), 2,2'-p-phenylenebis (4-hydro-5-methyl 1,3,6H-oxazine-6 -One), 2,2'-m-phenylenebis (4-hydro-5-methyl-1,3,6H-oxazin-6-one) and the like.
[0039]
The aziridine group represented by the formula (14) can be easily generated by reacting ethyleneimine with an acid chloride or the diisocyanate compound.
As the lactam group represented by the formula (15), R ^Ten Is preferably pyrrolidone, which is trimethylene, piperidone, which is tetramethylene, and caprolactam, which is pentamethylene, and can be easily produced by reacting lactams with an acid chloride or an isocyanate compound in the same manner as in formula (14).
Examples of the acid chloride used in these reactions are terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, succinic acid, and other derivatives.
[0040]
Reactive group X of linking agent (E) ¹ And X ² Is selected from the group of reactive groups represented by the above formulas (9) to (11) that can substantially react only with a hydroxyl group to form a covalent bond, a low molecular weight aliphatic polyester copolymer (D ) Is 2.0 or less, preferably 1.0 or less. When the acid value is larger than 2.0, the hydroxyl group terminal concentration of the copolymer (D) is small and the ligation reaction cannot be performed efficiently, or after the ligation reaction, that is, the acid value of the final product is large. There arises a problem that the molecular weight tends to decrease.
Reactive group X of linking agent (E) ¹ And X ² Is selected from the group of 3- to 8-membered cyclic reactive groups represented by the above formulas (12) to (15) that can substantially react only with a carboxyl group to form a covalent bond, a copolymer (D) The acid value of is preferably 0.5 or more and 30 or less. When the acid value is less than 0.5, the amount of the binder used is extremely small, and it is difficult to react uniformly. If the acid value is greater than 30, problems such as the fact that the acid value of the final product cannot be lowered and there is a risk of gelation using a large amount of a linking agent occur.
[0041]
The reaction of the coupling agent (E) and the copolymer (D) is preferably performed under conditions where the copolymer (D) is in a uniform molten state or contains a small amount of solvent and can be easily stirred. . The amount of the coupling agent (E) used is desirably 0.1 to 5 parts by weight with respect to 100 parts by weight of the copolymer (D). If the amount of the linking agent (E) is smaller than this, it is difficult to obtain a final product having a desired molecular weight. If the amount is larger, problems such as gelation tend to occur.
[0042]
In the present invention, it is necessary to select the feed ratio of the raw material (A) component and the (C) component so as to meet the following conditional expression (16).
0.02 ≦ [C] / ([A] + [C]) ≦ 0.40 (16)
(In the formula, [A] represents the number of moles of component (A) used, and [C] represents the number of moles of component (C) used.)
[C] / ([A] + [C]) in the above formula is the mole fraction (q of the repeating unit Q represented by the above formula (2) contained in the aliphatic polyester copolymer of the present invention. ). When this value is smaller than 0.02, the obtained polymer is hard and has high crystallinity and is not flexible, and further, the speed is low and insufficient in terms of biodegradability. On the other hand, if it is larger than 0.40, the melting point of the resulting polymer is low, and the crystallinity is extremely lowered, so that it has no heat resistance and is unsuitable for practical use.
[0043]
The high molecular weight aliphatic polyester copolymer of the present invention has a weight average molecular weight of 40,000 or more, usually 100,000 to 350,000, preferably 70,000 to 250,000. Moreover, the melting point is usually as high as 80 ° C. or higher, and the difference between the melting point and the decomposition temperature is as large as 100 ° C. or more, and thermoforming is easy.
In the aliphatic polyester copolymer of the present invention, in particular, R in the general formula (1) ¹ And R ² Is (CH ₂ ) ₂ Or (CH ₂ ) _Four And R ^Three Is (CH ₂ ) _Five Are those having a high melting point and high crystallinity.
[0044]
II. Other biodegradable resins
In the present invention, another biodegradable resin (b) can be further added to the aliphatic polyester copolymer (a).
As the other biodegradable resin (b), synthetic and / or natural polymers are used.
Synthetic polymers include aliphatic polyesters, polyamides, polyamide esters, biodegradable cellulose esters, polypeptides, polyvinyl alcohol, or mixtures thereof.
Of these, aliphatic polyesters, biodegradable cellulose esters, polypeptides, and polyvinyl alcohol are preferable.
[0045]
Examples of the synthetic aliphatic polyester resin include aliphatic polyester resins obtained by condensation polymerization and lactone resins obtained by ring-opening polymerization. Hereinafter, the synthetic aliphatic polyester resin is simply abbreviated as “aliphatic polyester resin”, and in the case of a product produced in nature, it is clearly stated.
Examples of aliphatic polyester resins include biodegradable polyester resins such as polylactone, polylactic acid, polyethylene succinate, and polybutylene succinate (such resins include low molecular weight fats represented by Bionore of Showa Polymer Co., Ltd. Polyester resins synthesized from aliphatic dicarboxylic acids and low molecular weight aliphatic diols), terpolymer aliphatic polyesters described in JP-A Nos. 9-235360 and 9-233958, Examples thereof include lactic acid and hydroxycarboxylic acid copolymers described in Kaihei 7-177826.
[0046]
Biodegradable cellulose esters include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; inorganic acid esters such as cellulose nitrate, cellulose sulfate, and cellulose phosphate; cellulose acetate butyrate, cellulose acetate phthalate, and nitric acid Examples include hybrid esters such as cellulose acetate. These cellulose esters can be used alone or in admixture of two or more. Of these cellulose esters, organic acid esters, particularly cellulose acetate, are preferred.
Examples of the polypeptide include polyamino acids such as polymethylglutamic acid and polyamide esters.
Examples of the polyamide ester include a resin synthesized from ε-caprolactone and ε-caprolactam.
As an example of the synthetic polymer, for example, an aliphatic polyester resin, a polymer having a number average molecular weight of 20,000 to 200,000, preferably 40,000 or more in terms of standard polystyrene by GPC can be used.
[0047]
Examples of the natural polymer include starch, cellulose, paper, pulp, cotton, hemp, hair, silk, leather, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof.
Examples of the starch include raw starch, modified starch, and mixtures thereof.
Raw starch includes corn starch, potato chopstick starch, sweet potato starch, wheat starch, cassava starch, sago starch, tapioca starch, rice starch, bean starch, kudzu starch, bracken starch, lotus starch, castor starch, etc. Starch includes physically modified starch (α-starch, fractionated amylose, wet heat-treated starch, etc.), enzyme-modified starch (hydrolyzed dextrin, enzyme-degraded dextrin, amylose, etc.), chemically modified starch (acid-treated starch, hypochlorous acid, etc.) Acid-oxidized starch, dialdehyde starch, etc.), chemically modified starch derivatives (esterified starch, etherified starch, cationized starch, crosslinked starch, etc.).
[0048]
Among the above, as esterified starch, acetate esterified starch, succinate esterified starch, nitrate esterified starch, phosphate esterified starch, urea phosphate esterified starch, xanthate esterified starch, acetoacetate esterified starch Etc .; As etherified starch, allyl etherified starch, methyl etherified starch, carboxymethyl etherified starch, hydroxyethyl etherified starch, hydroxypropyl etherified starch, etc .; As cationized starch, starch and 2-diethylaminoethyl chloride Reaction product of starch, reaction product of starch and 2,3-epoxypropyltrimethylammonium chloride, etc .; examples of the crosslinked starch include formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, phosphate crosslinked starch, acrolein crosslinked starch and the like.
The addition amount of the other biodegradable resin (b) is suitably 0.5 to 70 parts by weight, preferably 5 to 60 parts by weight with respect to 100 parts by weight of the aliphatic polyester copolymer (a). If the addition amount of the other biodegradable resin (b) exceeds 70 parts by weight, the excellent effect of the aliphatic polyester copolymer of the present invention is undesirably reduced, and if it is less than 0.5 parts by weight This is not preferable because the physical properties are substantially the same as those without addition, and only the cost required for compounding is required.
In particular, polylactic acid (PLA) is used for the purpose of controlling the biodegradation rate, but the weight ratio of the aliphatic polyester copolymer to the polylactic acid in the polyester blend resin composition of the present invention is 99.9. /0.1 to 70/30, preferably 99.9 / 0.1 to 80/20, more preferably 99.9 / 0.1 to 85/15. If the amount of polylactic acid is less than 0.1, the biodegradation delay effect in which polylactic acid is blended is not recognized, and if it is more than 30, the mechanical properties close to polyethylene, which is a feature of the polyester copolymer of the present invention, are impaired. It is. These make it possible to control the biodegradation rate particularly suitable for agricultural films.
[0049]
III. Other additives
The film-like molded product formed by molding the aliphatic polyester-based biodegradable resin of the present invention contains, in addition to the above other biodegradable resin (b), various other resin additives (c) as necessary. Can be added.
[0050]
Examples of the plasticizer include aliphatic dibasic acid esters, phthalic acid esters, hydroxy polycarboxylic acid esters, polyester plasticizers, fatty acid esters, epoxy plasticizers, and mixtures thereof.
Specifically, phthalic acid esters such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diisodecyl phthalate (DIDP), adipic acid-di-2-ethylhexyl (DOA), diisodecyl adipate (DIDA) and other adipic acid esters, azelaic acid-di-2-ethylhexyl (DOZ) and other azelaic acid esters, acetyltricitrate tri-2-ethylhexyl, acetylcitrate tributyl and other hydroxypolycarboxylic acid esters, polypropylene glycol Polyester plasticizers such as adipic acid esters, which are used alone or in a mixture of two or more.
The amount of these plasticizers to be added varies depending on the use of the film, but in general, an aliphatic polyester copolymer (a) or an aliphatic polyester copolymer (a) and a fat composed of another biodegradable resin (b). The range of 3 to 30 parts by weight is preferable, and the range of 5 to 15 parts by weight is particularly preferable with respect to 100 parts by weight of the aliphatic polyester series biodegradable resin. If it is less than 3 parts by weight, the elongation at break and impact strength are lowered, and if it exceeds 30 parts by weight, the break strength and impact strength may be reduced.
[0051]
As the heat stabilizer used in the present invention, there is an aliphatic carboxylate. As the aliphatic carboxylic acid, an aliphatic hydroxycarboxylic acid is particularly preferable. As the aliphatic hydroxycarboxylic acid, naturally occurring ones such as lactic acid and hydroxybutyric acid are preferable.
Examples of the salt include salts of sodium, calcium, aluminum, barium, magnesium, manganese, iron, zinc, lead, silver, copper and the like. These can be used as one kind or a mixture of two or more kinds.
As an addition amount, 100 parts by weight of an aliphatic polyester-based biodegradable resin composed of the aliphatic polyester copolymer (a) or the aliphatic polyester copolymer (a) and another biodegradable resin (b). , 0.5 to 10 parts by weight. When the heat stabilizer is used within the above range, the impact strength (Izod impact value) is improved, and there is an effect that variations in breaking elongation, breaking strength, and impact strength are reduced.
[0052]
As the lubricant used in the present invention, those generally used as an internal lubricant and an external lubricant can be used. For example, fatty acid ester, hydrocarbon resin, paraffin, higher fatty acid, oxy fatty acid, fatty acid amide, alkylene bis fatty acid amide, aliphatic ketone, fatty acid lower alcohol ester, fatty acid polyhydric alcohol ester, fatty acid polyglycol ester, aliphatic alcohol, many Examples thereof include monohydric alcohols, polyglycols, polychrycerols, metal soaps, modified silicones, or mixtures thereof. Preferably, fatty acid ester, hydrocarbon resin, etc. are mentioned.
When selecting a lubricant, it is necessary to select a lubricant having a melting point lower than that of the lactone resin or other biodegradable resin. For example, in view of the melting point of the aliphatic polyester resin, a fatty acid amide of 160 ° C. or lower is selected as the fatty acid amide.
When the film is taken as an example, the aliphatic polyester-based biodegradable resin comprising the aliphatic polyester copolymer (a) or the aliphatic polyester copolymer (a) and another biodegradable resin (b) 0.05 to 5 parts by weight of a lubricant is added to 100 parts by weight. If it is less than 0.05 parts by weight, the effect is not sufficient, and if it exceeds 5 parts by weight, it will not be wound on the roll, and the physical properties will also deteriorate.
For films, ethylenebisstearic acid amide, stearic acid amide, oleic acid amide, and erucic acid amide that are highly safe and registered with the FDA (US Food and Drug Administration) are preferable from the viewpoint of preventing environmental pollution. .
[0053]
Examples of the photodegradation accelerator include benzophenones such as benzoin, benzoin alkyl ethers, benzophenone, 4,4-bis (dimethylamino) benzophenone and derivatives thereof; acetophenone such as acetophenone and α, α-diethoxyacetophenone and Derivatives; quinones; thioxanthones; photoexciters such as phthalocyanines, anatase-type titanium oxide, ethylene-carbon oxide copolymers, sensitizers of aromatic ketones and metal salts, and the like. These photodegradation accelerators can be used alone or in combination of two or more.
[0054]
Examples of the biodegradation accelerator include oxo acids (for example, oxo acids having about 2 to 6 carbon atoms such as glycolic acid, lactic acid, citric acid, tartaric acid, malic acid), saturated dicarboxylic acids (for example, oxalic acid, malonic acid). Organic acids such as succinic acid, succinic anhydride, glutaric acid and the like, such as lower saturated dicarboxylic acids having about 2 to 6 carbon atoms, etc .; including lower alkyl esters of these organic acids and alcohols having about 1 to 4 carbon atoms It is. Preferred biodegradation accelerators include organic acids having about 2 to 6 carbon atoms such as citric acid, tartaric acid, malic acid, and coconut shell activated carbon. These biodegradation accelerators can be used alone or in combination of two or more.
The photodegradation accelerator or the addition amount of the photodegradation accelerator is an aliphatic polyester copolymer (a) or an aliphatic polyester composed of an aliphatic polyester copolymer (a) and another biodegradable resin (b). It is 0.001-5 weight part normally with respect to 100 weight part of system biodegradable resin.
[0055]
As fillers (including fillers), various fillers such as calcium carbonate, mica, calcium silicate, talc, finely divided silica (anhydrous), white carbon (hydrous), asbestos, porcelain clay (baked), barley rice Examples thereof include inorganic additives (also referred to as inorganic fillers) such as stone, various titanium oxides, and glass fibers, and organic additives (also referred to as organic fillers) such as particles of natural materials.
The fine powder silica as the inorganic filler may be silica prepared by a wet method or silica produced by high-temperature hydrolysis of silicon tetrachloride in an oxyhydrogen flame, but preferably has a particle size of 50 nm or less. .
[0056]
Organic fillers include fine powder particles made from paper having a diameter of 50 microns or less. The addition amount of the organic additive is the same as that of the inorganic additive.
Examples of the bulking agent include wood powder and glass balloon. The addition amount of the extender is the same as that of the inorganic additive.
The filler used in the present invention is preferably calcium carbonate and / or talc.
By adding a filler, the shape collapse rate is improved and the melt viscosity and melt hearing are increased, so that drawdown during melt molding is prevented, and moldability such as vacuum molding, blow molding and inflation molding is improved. .
[0057]
The amount of the filler added is that of the aliphatic polyester-based biodegradable resin comprising the filler / aliphatic polyester copolymer (a) or the aliphatic polyester copolymer (a) and another biodegradable resin (b). The weight ratio is 90-51 / 10-49, preferably 90-70 / 10-30.
When the amount of the filler is excessive, the resin blows the powder, and when it is too small, the draw down, necking, thickness unevenness and unevenness are noticeably generated during molding.
In the present invention, in addition to the above additives, a coloring inhibitor, an antioxidant, an organic or inorganic pigment, and the like can be added as necessary.
[0058]
Examples of the coloring inhibitor include phenolic ADK STAB AO-70 and phosphite ADK STAB 2112 (both manufactured by Asahi Denka Co., Ltd.).
The addition ratio is 100 parts by weight of an aliphatic polyester-based biodegradable resin composed of the aliphatic polyester copolymer (a) or the aliphatic polyester copolymer (a) and another biodegradable resin (b). 0.02 to 3 parts by weight, preferably 0.03 to 2 parts by weight.
Examples of the antioxidant include amine-based, phenol-based, phosphorus-based, sulfur-based, and the like, and the addition ratio is aliphatic polyester copolymer (a) or aliphatic polyester copolymer (a) and other biodegradable materials. It is 0.02-3 weight part with respect to 100 weight part of aliphatic polyester-type biodegradable resin which consists of resin (b).
[0059]
IV. Molding and application
Various films obtained by molding an aliphatic polyester-based biodegradable resin composition comprising the aliphatic polyester copolymer (a) or aliphatic polyester copolymer (a) of the present invention and another biodegradable resin (b) A shaped molded product can be obtained.
Molding includes primary molding into pellets, secondary molding into sheets, films, tapes (which include uniaxial or biaxially stretched materials, and transparency and mechanical strength are improved by stretching), and the like. Film, bags, especially degradable garbage bags, draining bags, shrink film (may be formed directly), perforated film, agricultural mulch (herbicide) film, vegetation film, solid film, root wound sheet, For drainage sheets, curing sheets, etc .; the laminated film can be processed into cards, etc., into closed cell cushioning sheets, padded cushioning materials, etc.
[0060]
In the case of a film-like molded product such as a film or sheet, T-die molding, inflation molding or calendar molding is usually used as the molding method, and uniaxial or biaxial stretching can also be performed without stretching.
[0061]
Below, the suitable example in the case of forming a film, especially the film by the inflation method is demonstrated.
First, in the aliphatic polyester copolymer (a), the ratio of the repeating unit (Q) derived from the lactone to the repeating unit (P) derived from the aliphatic polyester resin is 70% to 5% by weight of the latter. 30 to 95% by weight (total of 100% by weight of both) is preferable. In this case, the upper limit of the former is particularly preferably 60% by weight or less, and the latter is 60 to 90% by weight with respect to 40 to 10% by weight of the former. % Range is preferred.
In this case, if (Q) exceeds 70% by weight, the mechanical properties at high temperature of the molded product such as a film tend to be reduced, and if it is less than 5% by weight, the disintegration property based on biochemical decomposition may be reduced. . The same can be said when this tendency deviates from the range of 40 to 10% by weight.
On the other hand, if the amount of (P) exceeds 95% by weight, the biodegradability tends to be slow. Conversely, if it is less than 30% by weight, for example, when processed into a film, the heat resistance may be lowered. The same can be said when this tendency deviates from the range of 60 to 90% by weight.
[0062]
The blending ratio of the fatty acid amide as the lubricant is an aliphatic polyester copolymer (a) or an aliphatic polyester-based biodegradable material comprising the aliphatic polyester copolymer (a) and another biodegradable resin (b). Although 0.2-5 weight part is preferable with respect to 100 weight part of resin compositions, the range of 0.3-1.5 weight part is more preferable. When the fatty acid amide is less than 0.2 parts by weight, the blocking effect in the tube of the inflation film or the blocking effect between the film and the nip roll or the guide roll is slightly lowered. On the other hand, when it exceeds 5 parts by weight, the slipperiness of the film is more than necessary. It tends to be high, and the rollability of rolls, printability, adhesiveness, etc. begin to show a tendency to decrease.
[0063]
Furthermore, a liquid lubricant, fine powder silica, starch, etc. can be added as needed.
The purpose of using the liquid lubricant is that the copolymer or composition is usually supplied in the form of pellets or beads to the inflation film-forming process, and tries to uniformly mix fine powdered silica having a very low bulk specific gravity as described later. This is because the surface of the pellet or bead is preferably kept as wet as possible.
[0064]
The addition amount of the liquid lubricant having such a purpose of use is an aliphatic polyester copolymer (a) or an aliphatic polyester-based biopolymer comprising an aliphatic polyester copolymer (a) and another biodegradable resin (b). Preferably it is 0.1-3 weight part with respect to 100 weight part of decomposable resin compositions, More preferably, it adds in 0.2-0.7 weight part. If the added amount exceeds 3 parts by weight, a large amount of liquid lubricant may adhere to the inner surface of the mixing tumbler, and sticky and stable mixing may be difficult. If it is less than 0.1 parts by weight, the effect as a wetting agent is sufficient. There are some things that cannot be demonstrated. This tendency is also observed outside the more preferable range of 0.2 to 0.7 parts by weight.
On the other hand, the liquid lubricant as the wetting agent preferably has a melting point of 70 ° C. or lower, and more preferably used at room temperature. For example, in addition to liquid paraffin, paraffin wax, stearyl alcohol, stearic acid and the like, stearic acid esters such as butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, stearyl stearate and the like can be mentioned.
The most preferred fluid paraffin among the above liquid lubricants is very safe because it has an oral acute toxicity (rat) LD50 of 5 g / kg. It is recognized as a food additive in the Food Sanitation Law and is discarded after use of the film. This is a very convenient material in terms of preventing environmental pollution.
[0065]
As described above, a liquid lubricant was selected as the lubricant. However, when a solid lubricant is used, the entire system including the resin composition needs to be equal to or higher than the melting point of the solid lubricant. Then it is difficult to use. Liquid paraffin, which is liquid at room temperature, is a preferred lubricant in this respect.
The purpose of using finely divided silica is to prevent the blocking during inflation film and inflation film formation according to the present invention. The finely divided silica used is silica prepared by a wet method, silica produced by high-temperature hydrolysis of silicon tetrachloride in an oxyhydrogen flame, etc., especially those having a particle size of 50 nm or less. Is preferred.
[0066]
As an addition method, the aliphatic polyester copolymer (a) or aliphatic polyester copolymer (a) according to the present invention and an aliphatic polyester biodegradable resin composition comprising the other biodegradable resin (b) Or a method in which a fatty acid amide is further added to the resin composition is most preferable, and a considerably high shearing force acts to loosen the secondary agglomerated particles, thereby blocking between the films and between the film and each roll. Demonstrate the effect of preventing stickiness.
In addition, the addition amount of fine powder silica is 0. 0 parts by weight with respect to 100 parts by weight of the aliphatic polyester copolymer (a) or the mixture of the aliphatic polyester copolymer (a) and the other biodegradable resin (b). A range of 1 to 3 parts by weight is most preferable in view of the above effect.
[0067]
The aliphatic polyester copolymer (a) or the aliphatic polyester copolymer (a) and the other biodegradable resin (b) composed of the aliphatic polyester-based biodegradable resin composition added with the above-mentioned various additives. As a method for obtaining the composition, various methods conventionally used can be applied and are not particularly limited.
Kneading of an aliphatic polyester copolymer (a) or an aliphatic polyester copolymer (a) and an aliphatic polyester biodegradable resin composition comprising another biodegradable resin (b), and other additives (c) As a method, a general method can be preferably used. Specifically, raw resin pellets, powders, solid pieces, and the like are dry-mixed with a Henschel mixer or a ribbon mixer, and single or twin screw extruders or Banbury mixers. The mixture can be supplied to a known melt mixer such as a kneader or a mixing roll and melt kneaded.
[0068]
As the above-mentioned use, a film, a sheet, a foamed sheet and the like, and a secondary molded body thereof are particularly preferably used because they have biodegradability and do not cause any environmental problems even if disposed in soil such as landfill. be able to.
[0069]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
Various measured values of the aliphatic polyester copolymer in the examples were determined by the following methods.
(Molecular weight and molecular weight distribution)
A calibration curve was prepared from standard polystyrene using a gel permeation chromatography (GPC) method, and a number average molecular weight (Mn), a weight average molecular weight (Mw) and a molecular weight distribution (Mw / Mn) were determined. Chloroform was used as the eluent.
(Acid value and hydroxyl value)
Measurement was performed based on JIS K0070.
(Thermal properties)
A melting point and a glass transition point were determined by a differential scanning calorimeter (DSC).
(Mechanical strength)
Based on JIS K7113, the tensile elongation and strength of the test piece were determined.
[0070]
(Synthesis of aliphatic polyester copolymer)
[Production Example 1]
In a prepolymerization tank equipped with a stirrer, a fractionation condenser, and a temperature controller, 36.25 kg (402.2 mol) of 1,4-butanediol, 43.18 kg (365.7 mol) of succinic acid, and ε-caprolactone were added. 37 kg (64.6 mol) was charged all at once. [B] / [A] = 1.1 in the formula (8), and [C] / ([A] + [C]) = 0.15 in the formula (16).
Under normal pressure, the mixture was stirred at a temperature of 145 to 225 ° C. to carry out an esterification reaction. When the amount of the distillate exceeded 9.8 kg, the prepolymerization step was terminated, and the reaction solution was transferred to the main polymerization tank. Furthermore, 20.79 g of titanic acid tetraisopropyl ester was added to the polymerization tank, and the reaction solution was stirred while maintaining the temperature at 210 to 220 ° C., and finally the pressure was reduced to 1.0 Torr (133 Pa), and stirring was continued for 2 hours. 1,4-butanediol was distilled off, that is, transesterification was performed by deglycolization reaction. The obtained low molecular weight polyester had a weight average molecular weight of 53,000 and an acid value of 1.6 mg-KOH / g.
After completion of the deglycolization reaction, when the obtained low molecular weight polyester was melted at 190 ° C. and 773.7 kg of hexamethylene diisocyanate was added and stirred, the viscosity rapidly increased but gelation did not occur. The obtained aliphatic polyester copolymer (A: PCL / PBS = 15/85) had an Mw of 202,000, an acid value of 1.4 mgKOH / g, and a melting point of 101 ° C.
Mechanical strength is tensile strength 600kgf / cm ² The tensile elongation was 740%.
[0071]
[Production Example 2]
In the same prepolymerization tank as used in Production Example 1, 29.86 kg of 1,4-butanediol, 38.00 kg of succinic acid, and 12.24 kg of ε-caprolactone were charged all at once. Under normal pressure, the mixture was stirred at a temperature of 145 to 225 ° C. to carry out an esterification reaction. When the amount of the distillate exceeded 10.4 kg, the prepolymerization step was terminated, and the reaction solution was transferred to the main polymerization tank. Further, 18.29 g of titanic acid tetraisopropyl ester was added to the polymerization tank, and the reaction solution was stirred while maintaining the temperature at 210 to 220 ° C., and finally reduced in pressure to 1.0 Torr (133 Pa) and stirred for 3 hours to remove. A glycol reaction (a transesterification reaction) was performed. The obtained low molecular weight polyester had a weight average molecular weight of 93,000 and an acid value of 4.2 mg-KOH / g.
After completion of the deglycolization reaction, the low molecular weight polyester was melted at 190 ° C., and 1353 kg of 2,2′-m-phenylenebis (2-oxazoline) was added and stirred. There wasn't. The resulting aliphatic polyester copolymer (B: PCL / PBS = 25/75) had a Mw of 172,000, an acid value of 2.1 mg-KOH / g, a melting point of 88 ° C., and could be formed into a film. It was.
As for mechanical strength, tensile strength is 530 kgf / cm ² The tensile elongation was 800%.
[0072]
[Production Example 3]
In a prepolymerization tank equipped with a stirrer, a fractionation condenser, and a temperature control device, ethylene glycol (molecular weight: 62.07) 2.10 kg (33.79 mol), succinic acid (molecular weight: 118.09) 3.80 kg (32 .18 mol), 0.50 kg (4.39 mol) of ε-caprolactone (molecular weight: 114.14), 4.57 g of tetraisopropyl titanate, and 0.93 g of magnesium phosphate were charged all at once.
Under normal pressure, the mixture was stirred at a temperature of 145 to 235 ° C. to carry out an esterification reaction. When the amount of the distillate exceeded 1.15 kg, the prepolymerization step was terminated, and the reaction liquid was transferred to the main polymerization tank. The reaction solution was stirred while maintaining at 220 to 240 ° C., and finally the pressure was reduced to 0.6 Torr, and ethylene glycol was distilled for 9 hours with stirring, that is, a transesterification reaction was performed by deglycolization reaction. . The obtained polyester had a weight average molecular weight of 221,000, an acid value of 0.60 mg-KOH / g, a melting point of 90 ° C., Tg of −13 ° C., and caprolactone units relative to the total unit amount in the polymer determined by NMR. The proportion of the amount was 10.5 mol%.
The mechanical strength of the obtained polymer is that the tensile strength is 380 kgf / cm. ² The tensile elongation was 940% and it had mechanical properties suitable for multi-films. Moreover, it was possible to shape | mold into the film of the thickness of 100 micrometers or less.
[0073]
[Production Example 4]
1,4-butanediol 36.25 kg, succinic acid 43.18 kg, and ε-caprolactone 10.32 kg were charged together in a prepolymerization tank equipped with a stirrer, a fractionation condenser, and a temperature control device. Here, [B] / [A] = 1.09 in the equation (8) and [C] / ([A] + [C]) = 0.20 in the equation (16). Furthermore, 52.01 g of titanic acid tetraisopropyl ester and 10.46 g of dibasic magnesium phosphate trihydrate were added, and the mixture was stirred at a temperature of 145 to 225 ° C. under normal pressure to carry out an esterification reaction. When the amount of the distillate exceeded 10.0 kg, the prepolymerization step was terminated, and the reaction solution was transferred to the main polymerization tank. The reaction solution was kept at about 230 ° C. and stirred, and finally the pressure was reduced to 1.0 mmHg (133 Pa), followed by stirring for 4 hours to perform a deglycolization reaction (transesterification reaction). The obtained low molecular weight polyester (D) had a weight average molecular weight of 56,000 and an acid value of 1.6 mgKOH / g.
After completion of the deglycolization reaction, 600 g of hexamethylene diisocyanate was added in a molten state of the polyester (D) at 190 ° C. and stirred, the viscosity increased rapidly but no gelation occurred. The obtained high molecular weight aliphatic polyester copolymer of the present invention had an Mw of 182,000 and an acid value of 1.6 mgKOH / g. In DSC, a single melting peak appeared as in Production Example 1, the melting point was 96 ° C., and film formation was possible.
As for the mechanical strength of the film, the tensile strength is 310 kgf / cm. ² The tensile elongation was 660%.
[0074]
(Other biodegradable resins)
Abbreviations of other biodegradable resins used in Examples and Comparative Examples are shown below.
# 1001: Bionolle # 1001 (aliphatic dicarboxylic acid-aliphatic diol, manufactured by Showa Polymer Co., Ltd.)
# 3001: Bionolle # 3001 (aliphatic dicarboxylic acid-aliphatic diol system, manufactured by Showa Polymer Co., Ltd.)
PH7: Cell Green PH7 (polycaprolactone-based, manufactured by Daicel Chemical Industries)
[0075]
(Examples 1-4 and Reference Examples 1-2)
The aliphatic polyester copolymer produced in Production Example 4 and polylactic acid were melt-kneaded at a weight ratio shown in Table 1 below, and the resulting polyester blend resin composition was formed into an inflation film having a thickness of 20 μm. This film was cut and affixed to a non-biodegradable mold having a hole of 15 cm length × 10 cm width. Commercially available horticultural soil and humus soil were mixed at a weight ratio of 1: 1 and the water content was adjusted to 50% of the maximum water volume, and then the prepared sample was buried and kept at 23 ° C. while maintaining the water content. Left for days. A sample was taken out, the surface of the film was washed with water, dried, and the area of the holes opened in the film was subjected to image processing using Image Analyzer V10 manufactured by TOYOBO, and the void area was calculated.
Further, the polyester blend resin composition obtained in the same manner as described above was molded into a press piece having a length of 5 cm, a width of 5 cm, and a thickness of 600 μm at 150 ° C., and embedded in the soil adjusted in the same manner as described above. It was left for 30 days while holding. The sample was taken out, washed with water, dried and weighed. The table shows the weight loss rate from the sample before embedding.
As a reference example, the results when a similar test was performed using Bionore # 1001 instead of polylactic acid were shown.
[0076]
[Table 1]

[0077]
As described above, even when Bionore # 1001 which is slower in biodegradation than the aliphatic polyester copolymer (a) in the present invention is mixed, the effect of biodegradation control is hardly recognized. The effect is recognized.
[0078]
[Examples 5 to 9 and Reference Examples 3 to 5]
[compound]
The resin blended in the formulation shown in Table 2 below was compounded and pelletized using a twin screw extruder. The resin raw material used was previously dried (50 ° C. × 10 hours or more). A tumbler was used for each blend.
[0079]
[Film]
A film was obtained using the pellets obtained above.
Film take-off speed: 17.0 to 22.0 m / min
Lip width: 2.0mm
Film width: 1350mm
Film thickness: 20 μm
Various evaluations shown below were performed using the resin pellets and film-shaped moldings thus obtained, and the results are shown in Table 2.
[0080]
[Hand tearing]
Using polyethylene film (inflation molding), which is widely used as a general-purpose film, as a standard, the sense of tearing by hand is the standard (up to 10 points). The feeling when I was there was rated on a 10-point scale.
In this case, the overall tearability other than mere strength, such as resistance transmitted to the hand when it was torn by hand, how to tear (with or without linearity), and the waviness of the tear surface, was sensuously evaluated.
[0081]
The evaluation criteria for sensory evaluation are as follows.
A: The tearing surface is wavy and is torn diagonally, and has a high tear resistance.
○: The tear surface is straight and has little undulation, but it has a high tear resistance.
X: The tear surface is linear and the tear resistance is small.
Xx: Less tear resistance than x and easy to propagate tears.
[0082]
[Tear strength]
Sample: Each film obtained above was cut into a width of 50 mm and a length (MD direction) of 100 mm, and one end of the width was cut into a length of 30 mm from the middle.
The sample was conditioned for 24 hours with a constant temperature and humidity chamber of 23 ° C. × 50% RH and subjected to measurement.
<Tear strength measurement conditions>
Sample length: 30mm
Equipment used: Product name RTA-500, manufactured by OLIENTEC
Load cell: 5kgf, 20%
Crosshead speed: 500mm / min
The number of tests: n = 3, and the results are shown as average values.
The evaluation criteria for sensory evaluation are as follows.
A: Tear strength is strong, it is torn diagonally, and the tear surface is wavy.
○: Tear strength is strong, the tear surface is linear, and the tear surface is wavy.
X: The tear strength is weak and the tear surface is linear.
XX: The tear strength is very weak, the tear surface is linear, and the tear surface has almost no waviness.
[0083]
[Tensile test]
Each film obtained above was subjected to a tensile test using a punched piece of dumbbell No. 2 based on JIS K-7113. The film was punched in both MD and TD directions.
The sample was conditioned for 24 hours with a constant temperature and humidity machine of 23 ° C. × 50% RH and used for measurement. Measurement conditions are as follows.
<Tensile test measurement conditions>
Sample length: 40mm
Equipment used: Product name RTA-500, manufactured by OLIENTEC
Load cell: 10kgf, 40%
Crosshead speed: 500mm / min
The number of tests: n = 3, and the results are shown as average values.
[0084]
[Biodegradability]
Biodegradability was evaluated according to a simple degradation test (JIS K-6950) using activated sludge.
Using Himeji City standard activated sludge, biodegradability (weight%) after 28 days of the test period was measured. In addition, the biodegradability value obtained in the above test was indicated as x for 60% or less, ○ for 60% or more, and ◎ for 80% or more.
[0085]
[Decomposition rate]
Each film obtained above is punched into No. 2 dumbbell pieces according to JIS K-7113 and placed in horticultural soil, and buried for 60 hours under conditions of 28 ° C. × 99% RH. The above film was subjected to the tensile test, and the elongation in the TD direction was compared. In addition, the film after the said embedding is also called the film after decomposition | disassembly rate evaluation.
[0086]
[Table 2]

[0087]
Reference Example 3 is a system in which 90% by weight of # 1001 is added. However, because it contains a large amount of # 1001 having poor flexibility, both the molding processability and the initial film properties are not suitable for a thin film. . In addition, regarding the biodegradability, when 90% by weight of # 1001 was blended, the degradation rate was very slow, and the result was not suitable for applications such as multi-films used in a short period of time.
[0088]
Reference Examples 4 and 5 are systems in which # 1001 is reduced to 80% by weight, but the film performance is still not sufficient in the MD direction breaking elongation and further in the TD direction breaking elongation. In particular, it was not sufficient for multi-film applications. Although the tensile rupture elongation retention rate in the TD direction after the evaluation of the decomposition rate was high, the initial elongation was insufficient and this was not practical.
On the other hand, Examples 7 and 8 are systems in which the amount of addition of # 1001 is 30 parts by weight. There was no problem in molding processability, and the breaking elongation after film formation, particularly the breaking elongation in the TD direction, was greatly improved. Practicality comes out when the breaking elongation in the TD direction rises to over 700%. The rupture elongation in the TD direction after the evaluation of the decomposition rate at this time was well maintained.
Examples 6 and 9 are systems in which # 3001 and a flexible polyester which is a PH7 component are blended. As a result, the TD elongation at break was dramatically improved, and the tear strength was also greatly improved. The obtained film has a value sufficient for practical properties such as agricultural multi-film. Further, the elongation at break in the TD direction after the evaluation of the decomposition rate was well maintained.
[0089]
(Examples 10 to 14)
Table 3 below shows the production of an inflation film having a thickness of 20 μm using the high molecular weight aliphatic polyester copolymer A obtained in Production Example 1 and applying the lip width, blow ratio, extrusion temperature, and cooling method. The results of various evaluations are shown.
[0090]
[Table 3]

[0091]
From the above, it was confirmed that a biodegradable film, particularly a biodegradable multi-film for agriculture, having a controlled biodegradable rate and practical physical properties can be provided.
[0092]
【The invention's effect】
The film-like molded product obtained by molding the aliphatic polyester-based biodegradable resin of the present invention has industrial properties that can be supplied industrially and has practical properties. It is usable and useful.

Claims (12)

The molecular chain is represented by the general formula (1):
^{- (- CO-R 1 -COO} -R 2 -O -) - (1)
(In the formula, R ¹ represents a divalent aliphatic group having 1 to 12 carbon atoms, and R ² represents a divalent aliphatic group having 2 to 12 carbon atoms.)
A repeating unit (P) represented by the general formula (2):
^{- (- CO-R 3 -O} -) - (2)
(Wherein R ³ represents a divalent aliphatic group having 1 to 10 carbon atoms.)
Repeating unit (Q)
The aliphatic polyester random copolymer (a) having a weight average molecular weight of 40,000 or more, or a fat comprising the aliphatic polyester random copolymer (a) and another biodegradable resin (b) A biodegradable resin film-like molded product obtained by molding a group polyester-based biodegradable resin composition. The molar fraction (q) of the repeating unit Q represented by the formula (2) contained in the aliphatic polyester random copolymer (a) is 0.02 or more and 0.40 or less. Biodegradable resin film molding. The aliphatic polyester random copolymer (a) is a polymerization intermediate of the aliphatic polyester random copolymer (a), and the low molecular weight aliphatic polyester copolymer (D) 100 weight is 5,000 or more To 5 parts by weight of the general formula (7):
X ¹ -R ⁷ -X ² (7)
(In the formula, X ¹ and X ² represent a reactive group capable of forming a covalent bond by acting with a hydroxyl group or a carboxyl group, R ⁷ represents a single bond, an aliphatic group having 1 to 20 carbon atoms or an aromatic group; ¹ and X ² may have the same chemical structure or may be different)
The biodegradable resin film-like molded product according to claim 1 or 2 , which is linked by a bifunctional coupling agent (E) represented by formula (1). General formula (1) is a condensation reaction from aliphatic carboxylic acids containing succinic acid residues and / or adipic acid residues, and aliphatic glycols containing ethylene glycol residues and / or 1,4-butanediol residues. The biodegradable resin film-like molded product according to any one of claims 1 to 3, wherein the biodegradable resin film-like molded product is a structure produced by the process. General formula (2) is ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone, 3,3,5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, enanthate The biodegradable resin film-like molded product according to any one of claims 1 to 3, wherein the biodegradable resin film-shaped molded product is at least one residue selected from the group consisting of lactones. The reactive group of the bifunctional linking agent (E) represented by the general formula (7) is an isocyanate group, an isothiocyanate group, an epoxy group, an oxazoline group, an oxazolone group or an oxazinone group, an aziridine group, or a mixed group thereof. The biodegradable resin film-like molded product according to claim 3, wherein The other biodegradable resin (b) is blended in an amount of 0.5 to 70 parts by weight with respect to 100 parts by weight of the aliphatic polyester copolymer (a) . The biodegradable resin film-shaped molded product described in 1. The other biodegradable resin (b) is a synthetic polymer selected from polylactic acid, aliphatic polyester excluding polylactic acid , biodegradable cellulose ester, polypeptide, polyvinyl alcohol, and mixtures thereof . 8. The biodegradable resin film-like molded product according to any one of 7 above. Other biodegradable resins (b) are starch, cellulose, paper, pulp, cotton, hemp, wool, silk, leather, carrageenan, chitin / chitosan, natural linear polyester resins, and mixtures thereof The biodegradable resin film-like molded product according to any one of claims 1 to 7, which is a natural polymer selected . The biodegradable resin film-shaped molded article is a shrink film. The biodegradable resin film-shaped molded article according to any one of claims 1 to 9 . The biodegradable resin film-shaped molded product is a laminated film. The biodegradable resin film-shaped molded product according to any one of claims 1 to 9 . The biodegradable resin film-shaped molded article is an agricultural multi-film, and the biodegradable resin film-shaped molded article according to any one of claims 1 to 9 .