JP2004002803A - Polyester composition, and hollow molding, sheet-shaped article and stretched film consisting of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition excellent in crystallization-controlling property and long time continuous molding property in melt molding, and a hollow molding obtained from the same, excellent in transparency and heat resistant dimensional stability, especially having an appropriate range of mouth-capping part shrinkage of the hollow molding, and hardly generating a residual nasty taste and smell on using it as a liquid container, a sheet-shaped article and a stretched film. <P>SOLUTION: This polyester composition consisting of polyester chips having main recurring units of ethylene terephthalate, and 0.1-5,000 ppm polyester fine having the same composition is provided by exhibiting ≤195°C crystallization temperature by falling temperature (Tc2') of the polyester fine measured by a DSC (differential scanning calorimeter) and ≤0.50 wt. % increased amount of cyclic trimer on melting the polyester composition at 290°C for 60 min. <P>COPYRIGHT: (C)2004,JPO

Description

【００５６】
水処理槽に導入する水中の粒子個数、ナトリウム、マグネシウム、カルシウム、珪素の含有量のいずれかを上記範囲に設定することにより、スケールと呼ばれる酸化物や水酸化物等の金属含有物質が処理水中に浮遊、沈殿、さらには処理槽壁や配管壁に付着したりし、これがポリエステルチップに付着、浸透して、成形時での結晶化が促進され、透明性の悪いボトルになることを防ぐことができる。
【００５７】
水処理槽に導入する水中の粒子数を５００００個／１０ｍｌ以下にする方法としては、工業用水等の自然水を処理槽に供給するまでの工程の少なくとも１ヶ所以上に粒子を除去する装置を設置する。
【００５８】
また水処理槽に導入する水中のナトリウムやマグネシウム、カルシウム、珪素を低減させるために、工業用水等の自然水を処理槽に供給するまでの工程で少なくとも１ヶ所以上にナトリウムやマグネシウム、カルシウム、珪素を除去する装置を設置する。これらの装置としてはチップ冷却水の処理に使用するのと同様の装置が挙げられる。
【００５９】
またポリエステルのチップと水蒸気または水蒸気含有ガスとを接触させて処理する場合は、５０〜１５０℃、好ましくは５０〜１１０℃の温度の水蒸気または水蒸気含有ガスあるいは水蒸気含有空気を好ましくは粒状ポリエチレンテレフタレ−ト１ｋｇ当り、水蒸気として０．５ｇ以上の量で供給させるか、または存在させて粒状ポリエチレンテレフタレ−トと水蒸気とを接触させる。
【００６０】
この、ポリエステルのチップと水蒸気との接触は、通常１０分間〜２日間、好ましくは２０分間〜１０時間行われる。
【００６１】
以下に粒状ポリエチレンテレフタレ−トと水蒸気または水蒸気含有ガスとの接触処理を工業的に行なう方法を例示するが、これに限定されるものではない。また処理方法は連続方式、バッチ方式のいずれであっても差し支えない。
【００６２】
ポリエステルのチップをバッチ方式で水蒸気と接触処理をする場合は、サイロタイプの処理装置が挙げられる。すなわちポリエステルのチップをサイロへ受け入れ、バッチ方式で、水蒸気または水蒸気含有ガスを供給し接触処理を行なう。
【００６３】
ポリエステルのチップを連続的に水蒸気と接触処理する場合は塔型の処理装置に連続で粒状ポリエチレンテレフタレ−トを上部より受け入れ、並流あるいは向流で水蒸気を連続供給し水蒸気と接触処理させることができる。
【００６４】
上記の如く、水又は水蒸気で処理した場合は粒状ポリエチレンテレフタレ−トを必要に応じて振動篩機、シモンカ−タ−などの水切り装置で水切りし、コンベヤ−によって次の乾燥工程へ移送する。
【００６５】
水又は水蒸気と接触処理したポリエステルのチップの乾燥は通常用いられるポリエステルの乾燥処理を用いることができる。連続的に乾燥する方法としては、上部よりポリエステルのチップを供給し、下部より乾燥ガスを通気するホッパ−型の通気乾燥機が通常使用される。
バッチ方式で乾燥する乾燥機としては大気圧下で乾燥ガスを通気しながら乾燥してもよい。
【００６６】
乾燥ガスとしては大気空気でも差し支えないが、ポリエステルの加水分解や熱酸化分解による分子量低下を防止する点からは乾燥窒素、除湿空気が好ましく、なかでも乾燥窒素が好都合である。
【００６７】
また重縮合触媒を失活させる別の手段として、リン化合物を溶融重縮合後または固相重合後のポリエステルの溶融物に添加、混合して重合触媒を不活性化する方法が挙げられる。
【００６８】
溶融重合ポリエステルの場合には、溶融重合反応終了後のポリエステルと、リン化合物を配合したポリエステル樹脂とを溶融状態で混合できるラインミキサ−等の機器中で混合して重縮合触媒を不活性化する方法が挙げられる。
【００６９】
また固相重合ポリエステルにリン化合物を配合する方法としては、固相重合ポリエステルにリン化合物をドライブレンドする方法やリン化合物を溶融混練して配合したポリエステルマスタ−バッチチップと固相重合ポリエステルチップを混合する方法によって所定量のリン化合物をポリエステルに配合後、押出機や成形機中で溶融し、重縮合触媒を不活性化する方法等が挙げられる。
【００７０】
使用されるリン化合物としては、リン酸、亜リン酸、ホスホン酸およびそれらの誘導体等が挙げられる。具体例としてはリン酸、リン酸トリメチルエステル、リン酸トリエチルエステル、リン酸トリブチルエステル、リン酸トリフェニ−ルエステル、リン酸モノメチルエステル、リン酸ジメチルエステル、リン酸モノブチルエステル、リン酸ジブチルエステル、亜リン酸、亜リン酸トリメチルエステル、亜リン酸トリエチルエステル、亜リン酸トリブチルエステル、メチルホスホン酸、メチルホスホン酸ジメチルエステル、エチルホスホン酸ジメチルエステル、フェニ−ルホスホン酸ジメチルエステル、フェニ−ルホスホン酸ジエチルエステル、フェニ−ルホスホン酸ジフェニ−ルエステル等であり、これらは単独で使用してもよく、また２種以上を併用してもよい。
【００７１】
また本発明のポリエステル組成物の環状三量体の含有量は、好ましくは０．７０重量％以下、より好ましくは０．５０重量％以下、さらに好ましくは０．４０重量％以下である。本発明のポリエステル組成物から耐熱性の中空成形体等を成形する場合は加熱金型内で熱処理を行うが、環状三量体の含有量が０．７０重量％以上含有する場合には、加熱金型表面へのオリゴマ−付着が急激に増加し、得られた中空成形体等の透明性が非常に悪化する場合がある。
【００７２】
また、本発明に係るポリエステルは、チップ化工程の冷却水中のナトリウムの含有量、マグネシウムの含有量、珪素の含有量及びカルシウムの含有量をそれぞれＮ、Ｍ、Ｓ、Ｃとした場合、下記の（１）〜（４）の少なくとも一つ、好ましくはすべてを満足するようにして溶融重縮合後にチップ化されたポリエステルであることが好ましい。
Ｎ　　≦　　１．０（ｐｐｍ）　　　　　　　　　（１）
Ｍ　　≦　　０．５（ｐｐｍ）　　　　　　　　　（２）
Ｓ　　≦　　２．０（ｐｐｍ）　　　　　　　　　（３）
Ｃ　　≦　　１．０（ｐｐｍ）　　　　　　　　　（４）
【００７３】
冷却水中のナトリウム含有量（Ｎ）は、好ましくはＮ≦０．５ｐｐｍであり、さらに好ましくはＮ≦０．１ｐｐｍである。
冷却水中のマグネシウム含有量（Ｍ）は、好ましくはＭ≦０．３ｐｐｍであり、さらに好ましくはＭ≦０．１ｐｐｍである。
また、冷却水中の珪素の含有量（Ｓ）は、好ましくはＳ≦０．５ｐｐｍであり、さらに好ましくはＳ≦０．３ｐｐｍである。
さらに、冷却水中のカルシウム含有量（Ｃ）は、好ましくはＣ≦０．５ｐｐｍであり、さらに好ましくはＣ≦０．１ｐｐｍである。
【００７４】
また、冷却水中のナトリウム含有量（Ｎ）、マグネシウム含有量（Ｍ）、珪素の含有量（Ｓ）およびカルシウム含有量（Ｃ）の下限値は、Ｎ≧０．００１ｐｐｍ、Ｍ≧０．００１ｐｐｍ、Ｓ≧０．０２ｐｐｍおよびＣ≧０．００１ｐｐｍである。このような下限値以下にするには、莫大な設備投資が必要であり、また運転費用も非常に高くなり経済的な生産は困難となる場合がある。
【００７５】
前記の条件を外れる冷却水を用いた場合には、これらの金属含有化合物がポリエステルチップ表面に付着し、得られたポリエステルの結晶化速度が非常に早く、またその変動が大きくなり好ましくない。工業用水中の前記の金属の含有量は１年を通じてかなり変動しており、この変動に応じてポリエステルに付着する金属含有量が変動するからか、前記の（１）〜（４）の少なくとも一つを満足する冷却水を用いた場合に比較して、工業用水をチップ化時の冷却水として用いて得られたポリエステルからの成形体の透明性が悪く、かつその変動が非常に大きい。なお、前記（１）〜（４）はすべてを満足することが好ましい。
【００７６】
また、前記の条件を外れる冷却水を用いて冷却しながらチップ化した溶融重縮合ポリエステルを固相重合すると、チップ化工程においてチップ表面に付着して固相重合反応装置に持ち込まれた前記の金属含有物質は、ポリエステルチップの表面層の一部と共に固相重合装置の器壁に固着し、これが約１７０℃以上の高温度での長時間加熱によって金属含有量の高いスケールとなって器壁に付着していく。そして、これが時々剥離してポリエステルチップ中に混入し、ボトル等成形体中の異物となって商品価値を低下さすという問題が発生することがある。
【００７７】
また、シ−トを製造する際には、製膜時に前記のスケ−ルが溶融ポリマ−濾過フィルタ−に詰まるためフィルタ−濾過圧の上昇が激しくなり、操業性や生産性が悪くなるという問題も発生することがある。
【００７８】
以下にチップの冷却水のナトリウム含有量、マグネシウム含有量、珪素含有量、カルシウム含有量を前記の範囲に抑える方法を例示するが、本発明はこれに限定するものではない。
【００７９】
冷却水のナトリウムやマグネシウム、カルシウム、珪素を低減させるために、チップ化工程に工業用水が送られるまでの工程で少なくとも１ヶ所以上にナトリウムやマグネシウム、カルシウム、珪素を除去する装置を設置する。また、粒子状になった二酸化珪素やアルミノ珪酸塩等の粘土鉱物を除去するためにはフィルターを設置する。ナトリウムやマグネシウム、カルシウム、珪素を除去する装置としては、イオン交換装置、限外濾過装置や逆浸透膜装置などが挙げられる。
【００８０】
また、系外から導入する導入水の中に存在する粒径が１〜２５μｍの粒子を５００００個／１０ｍｌ以下にした水を使用することが望ましい。導入水中の粒径１〜２５μｍの粒子の個数は、好ましくは１００００個／１０ｍｌ以下、さらに好ましくは１０００個／１０ｍｌ以下、特に好ましくは１００個／１０ｍｌ以下である。
【００８１】
また、本発明のポリエステル組成物は、前記のポリエステル組成物にポリオレフィン樹脂、ポリアミド樹脂、ポリアセタ−ル樹脂からなる群から選ばれた少なくとも一種の樹脂０．１ｐｐｂ〜５００００ｐｐｍを配合してなることを特徴とするポリエステル組成物である。本発明において用いられる前記樹脂のポリエステルへの配合割合は、０．１ｐｐｂ〜５００００ｐｐｍ、好ましくは０．３ｐｐｂ〜１００００ｐｐｍ、より好ましくは０．５ｐｐｂ〜１００ｐｐｍ、さらに好ましくは１．０ｐｐｂ〜１ｐｐｍ、特に好ましくは１．０ｐｐｂ〜４５ｐｐｂである。配合量が０．１ｐｐｂ未満の場合は、結晶化速度が非常におそくなり、中空成形体の口栓部の結晶化が不十分となるため、サイクルタイムを短くすると口栓部の収縮量が規定値範囲内におさまらないためキャッピング不良となったり、また、耐熱性中空成形体を成形する延伸熱固定金型の汚れが激しく、透明な中空成形体を得ようとすると頻繁に金型掃除をしなければならない場合がある。また５００００ｐｐｍを超える場合は、結晶化速度が早くなり、中空成形体の口栓部の結晶化が過大となり、このため口栓部の収縮収縮量が規定値範囲内におさまらないためキャッピング不良となり内容物の漏れが生じたり、また中空成形体用予備成形体が白化し、このため正常な延伸が不可能となる場合がある。また、シ−ト状物の場合、５００００ｐｐｍを越えると透明性が非常に悪くなり、また延伸性もわるくなって正常な延伸が不可能で、厚み斑の大きな、透明性の悪い延伸フイルムしか得られないことがある。
【００８２】
本発明のポリエステル組成物に配合されるポリオレフィン樹脂としては、ポリエチレン系樹脂、ポリプロピレン系樹脂、またはα−オレフィン系樹脂が挙げられる。またこれらの樹脂は結晶性でも非晶性でもかまわない。
【００８３】
本発明のポリエステル組成物に配合されるポリエチレン系樹脂としては、例えば、エチレンの単独重合体、エチレンと、プロピレン、ブテン−１、３−メチルブテン−１、ペンテン−１、４−メチルペンテン−１、ヘキセン−１、オクテン−１、デセン−１等の炭素数２〜２０程度の他のα−オレフィンや、酢酸ビニル、塩化ビニル、アクリル酸、メタクリル酸、アクリル酸エステル、メタクリル酸エステル、スチレン、不飽和エポキシ化合物等のビニル化合物との共重合体等が挙げられる。具体的には、例えば、超低・低・中・高密度ポリエチレン等（分岐状又は直鎖状）のエチレン単独重合体、エチレン−プロピレン共重合体、エチレン−ブテン−１共重合体、エチレン−４−メチルペンテン−１共重合体、エチレン−ヘキセン−１共重合体、エチレン−オクテン−１共重合体、エチレン−酢酸ビニル共重合体、エチレン−アクリル酸共重合体、エチレン−メタクリル酸共重合体、エチレン−アクリル酸エチル共重合体等のエチレン系樹脂が挙げられる。
【００８４】
また本発明のポリエステル組成物に配合されるポリプロピレン系樹脂としては、例えば、プロピレンの単独重合体、プロピレンと、エチレン、ブテン−１、３−メチルブテン−１、ペンテン−１、４−メチルペンテン−１、ヘキセン−１、オクテン−１、デセン−１等の炭素数２〜２０程度の他のα−オレフィンや、酢酸ビニル、塩化ビニル、アクリル酸、メタクリル酸、アクリル酸エステル、メタクリル酸エステル、スチレン等のビニル化合物との共重合体、あるいはヘキサジエン、オクタジエン、デカジエン、ジシクロペンタジエン等のジエンとの共重合体等が挙げられる。具体的には、例えば、プロピレン単独重合体（アタクチック、アイソタクチック、シンジオタクチックポリプロピレン）、プロピレン−エチレン共重合体、プロピレン−エチレン−ブテン−１共重合体等のプロピレン系樹脂が挙げられる。
【００８５】
また本発明のポリエステル組成物に配合されるα−オレフィン系樹脂としては、４−メチルペンテン−１等の炭素数２〜８程度のα−オレフィンの単独重合体、それらのα−オレフィンと、エチレン、プロピレン、ブテン−１、３−メチルブテン−１、ペンテン−１、ヘキセン−１、オクテン−１、デセン−１等の炭素数２〜２０程度の他のα−オレフィンとの共重合体等が挙げられる。具体的には、例えば、ブテン−１単独重合体、４−メチルペンテン−１単独重合体、ブテン−１−エチレン共重合体、ブテン−１−プロピレン共重合体等のブテン−１系樹脂や４−メチルペンテン−１とＣ_２〜Ｃ_１８のα−オレフィンとの共重合体、等が挙げられる。
【００８６】
また、本発明のポリエステル組成物に配合されるポリアミド樹脂としては、例えば、ブチロラクタム、δ−バレロラクタム、ε−カプロラクタム、エナントラクタム、ω−ラウロラクタム等のラクタムの重合体、６−アミノカプロン酸、１１−アミノウンデカン酸、１２−アミノドデカン酸等のアミノカルボン酸の重合体、ヘキサメチレンジアミン、ノナメチレンジアミン、デカメチレンジアミン、ドデカメチレンジアミン、ウンデカメチレンジアミン、２，２，４−又は２，４，４−トリメチルヘキサメチレンジアミン等の脂肪族ジアミン、１，３−又は１，４−ビス（アミノメチル）シクロヘキサン、ビス（ｐ−アミノシクロヘキシルメタン）等の脂環式ジアミン、ｍ−又はｐ−キシリレンジアミン等の芳香族ジアミン等のジアミン単位と、グルタル酸、アジピン酸、スベリン酸、セバシン酸等の脂肪族ジカルボン酸、シクロヘキサンジカルボン酸等の脂環式ジカルボン酸、テレフタル酸、イソフタル酸等の芳香族ジカルボン酸等のジカルボン酸単位との重縮合体、及びこれらの共重合体等が挙げられ、具体的には、例えば、ナイロン４、ナイロン６、ナイロン７、ナイロン８、ナイロン９、ナイロン１１、ナイロン１２、ナイロン６６、ナイロン６９、ナイロン６１０、ナイロン６１１、ナイロン６１２、ナイロン６Ｔ、ナイロン６Ｉ、ナイロンＭＸＤ６、ナイロン６／ＭＸＤ６、ナイロンＭＸＤ６／ＭＸＤＩ、ナイロン６／６６、ナイロン６／６１０、ナイロン６／１２、ナイロン６／６Ｔ、ナイロン６Ｉ／６Ｔ等が挙げられる。またこれらの樹脂は結晶性でも非晶性でもかまわない。
【００８７】
また、本発明のポリエステル組成物に配合されるポリアセタ−ル樹脂としては、例えばポリアセタ−ル単独重合体や共重合体が挙げられる。ポリアセタ−ル単独重合体としては、ＡＳＴＭ−Ｄ７９２の測定法により測定した密度が１．４０〜１．４２ｇ／ｃｍ^３、ＡＳＴＭＤ−１２３８の測定法により、１９０℃、荷重２１６０ｇで測定したメルトフロー比（ＭＦＲ）が０．５〜５０ｇ／１０分の範囲のポリアセタ−ルが好ましい。
【００８８】
また、ポリアセタ−ル共重合体としては、ＡＳＴＭ−Ｄ７９２の測定法により測定した密度が１．３８〜１．４３ｇ／ｃｍ^３、ＡＳＴＭＤ−１２３８の測定法により、１９０℃、荷重２１６０ｇで測定したメルトフロー比（ＭＦＲ）が０．４〜５０ｇ／１０分の範囲のポリアセタ−ル共重合体が好ましい。これらの共重合成分としては、エチレンオキサイドや環状エ−テルが挙げられる。
【００８９】
本発明における前記のポリオレフィン樹脂等を配合したポリエステル組成物の製造は、前記ポリエステルに前記ポリオレフィン樹脂等の樹脂を、その含有量が前記範囲となるように直接に添加し溶融混練する方法、または、マスタ−バッチとして添加し溶融混練する方法等の慣用の方法によるほか、前記樹脂を、前記ポリエステルの製造段階、例えば、溶融重縮合時、溶融重縮合直後、予備結晶化直後、固相重合時、固相重合直後等のいずれかの段階、または、製造段階を終えてから成形段階に到るまでの工程などで、粉粒体として直接に添加するか、或いは、前記ポリエステルチップを流動条件下に前記樹脂製部材に接触させる等の方法で混入させる方法、または前記の接触処理後、溶融混練する方法等によることもできる。
【００９０】
ここで、ポリエステルチップを流動条件下に前記樹脂製の部材に接触させる方法としては、前記樹脂製の部材が存在する空問内で、ポリエステルチップを前記部材に衝突接触させることが好ましく、具体的には、例えば、ポリエステルの溶融重縮合直後、予備結晶化直後、固相重合直後等の製造工程時、また、ポリエステルチップの製品としての輸送段階等での輸送容器充填・排出時、また、ポリエステルチップの成形段階での成形機投入時、等における気力輸送配管、重力輸送配管、サイロ、マグネットキャッチャ−のマグネット部等の一部を前記樹脂製とするか、前記樹脂製フイルム、シート、成形体などを貼り付けるか、または、前記樹脂をライニングするとか、或いは前記移送経路内に棒状又は網状体等の前記樹脂製部材を設置する等して、ポリエステルチップを移送する方法が挙げられる。ポリエステルチップの前記部材との接触時間は、通常、０．０１秒〜数分程度の極短時間であるが、ポリエステルに前記樹脂を微量混入させることができる。
【００９１】
また、溶融重縮合工程または固相重合工程以降のポリエステルと接触する気体として、粒径０．３〜５μｍの粒子が１００００００（個／立方フィ−ト）以下の、好ましくは５０００００（個／立方フィ−ト）以下、さらに好ましくは１０００００（個／立方フィ−ト）以下の、系外より導入される気体を使用することが望ましい。気体中の粒径５μｍを超える粒子は、特に限定するものではないが、好ましくは５（個／立方フィ−ト）以下、さらに好ましくは１（個／立方フィ−ト）以下である。
【００９２】
ポリエステルの製造工程において、溶融重縮合工程や固相重合工程等から篩分工程や気流分級工程等の各工程を経由してサイロ、成形機のホッパ−、輸送用コンテナ−等の容器に充填されるが、これらの工程間のポリエステルの輸送や乾燥には、一般に送風機等によって処理設備近辺の空気を工程に採りいれて使用される。従来は、このような空気は、これを未処理のままで使用するか、または、ＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式３のような低性能フィルタユニットを装着した清浄機によって処理しただけで使用するのが一般的であった。
しかし、このような工程で処理されたポリエステルからは、透明性が悪い成形体しか得られないという問題が生じる場合があった。特に、前記樹脂からなる部材との接触処理工程の前後において、ポリエステルと接触する気体として前記のような品質の空気を用いると、得られた成形体の結晶化速度や透明性等の変動が大となり問題となる可能性が大きい。
【００９３】
したがって、本発明のポリエステル組成物の製造方法においては、溶融重縮合後、固相重合後、水処理後あるいは前記樹脂からなる部材との接触処理後のポリエステルのうち、少なくとも一つのポリエステルが、次工程への輸送工程、篩分工程、貯蔵工程、容器充填工程のいづれか一つの工程において接触する気体として、粒径０．３〜５μｍの粒子が１００００００（個／立方フィ−ト）以下の系外より導入される気体を使用することが望ましい。
【００９４】
以下に、系外から導入する気体中の粒径０．３〜５μｍの粒子数を１００００００（個／立方フィ−ト）以下に制御する方法を例示するが、本発明はこれに限定するものではない。
系外から導入する気体中の粒径０．３〜５μｍの粒子数を１００００００（個／立方フィ−ト）以下にする方法としては、系外から導入する気体がポリエステルチップと接触するまでの工程中の少なくとも１ケ所以上に前記粒子を除去する清浄化装置を設置する。前記気体が処理設備近辺の空気の場合は、前記空気採りいれ口から送風機によって導入した空気がポリエステルチップと接触するまでの工程中に、ＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式１又は／及び形式２のフィルタユニットを装着した気体清浄装置を設置し、前記空気中の粒径０．３〜５μｍの粒子数を１００００００（個／立方フィ−ト）以下にすることが好まし。また、前記空気採りいれ口にＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式３のフィルタユニットを装着した気体清浄装置を設置して、前記のフィルタユニットを装着した気体清浄装置と併用することによって前記のフィルタユニットの寿命を延ばすことが可能である。
【００９５】
気体中の粒子を除去するＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式１の超高性能のフィルタ（以下、ＨＥＰＡフィルタと略称する）ユニットの素材としては、ガラス繊維からなる濾紙が挙げられる。
また、ＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式２の高性能フィルタユニットの素材としては、ポリプロピレン繊維からなるフィルタやテフロン（Ｒ）フイルムとＰＥＴ繊維布の積層体からのフィルタ等が挙げられる。
一般には、ポリプロピレン繊維製の静電フィルタが使用される。
【００９６】
また、ＪＩＳ　Ｂ　９９０８（１９９１）で規定される形式３の低性能フィルタユニットの素材としては、ＰＥＴやポリプロピレンからなる不織布等が挙げられる。
【００９７】
本発明のポリエステル組成物の極限粘度は、０．５５〜１．５０デシリットル／グラムであるのが好ましく、０．５８〜１．２０デシリットル／グラムであるのがより好ましい。ポリエステルの極限粘度が０．５５デシリットル／グラム未満の場合は、本発明のポリエステル組成物を溶融成形して得られた成形体の透明性、耐熱性、機械特性等が充分満足されないことがある。また、極限粘度が１．５０デシリットル／グラムを越える場合は、成型機等による溶融時に樹脂温度が高くなって熱分解が激しくなり、保香性に影響を及ぼす遊離の低分子量化合物が増加したり、成形体が黄色に着色する等の問題が起こる場合がある。
【００９８】
また、本発明のポリエステル組成物のアセトアルデヒド含有量は、５０ｐｐｍ以下、好ましくは３０ｐｐｍ以下、より好ましくは１０ｐｐｍ以下、さらに好ましくは５ｐｐｍ以下である。アセトアルデヒド含有量が５０ｐｐｍ以上の場合は、このポリエステルから成形された容器等の内容物の風味や臭い等が悪くなる場合がある。
【００９９】
また本発明に係るポリエステル中に共重合されたジエチレングリコ−ル量は、前記ポリエステルを構成するグリコ−ル成分の好ましくは０．５〜５．０モル％、より好ましくは１．０〜４．５モル％、さらに好ましくは１．５〜４．０モル％である。ジエチレングリコ−ル量が５．０モル％を越える場合は、熱安定性が悪くなり、成型時に分子量低下が大きくなったり、またアセトアルデヒド含有量やホルムアルデヒド含有量の増加量が大となり好ましくない。またジエチレングリコ−ル含有量が０．５モル％未満の場合は、得られた成形体の透明性が悪くなる場合がある。
【０１００】
また本発明のポリエステル組成物の環状三量体の含有量は、前記のように、０．７０重量％以下、好ましくは０．５０重量％以下、さらに好ましくは０．４０重量％以下である。本発明のポリエステル組成物から耐熱性の中空成形体等を成形する場合は加熱金型内で熱処理を行うが、前記したように環状三量体の含有量が０．７０重量％を越える場合には、加熱金型表面へのオリゴマ−付着が急激に増加し、得られた中空成形体等の透明性が非常に悪化する場合がある。
【０１０１】
本発明において、ポリエステルのチップの形状は、シリンダ−型、角型、球状または扁平な板状等の何れでもよい。その平均粒径は通常１．５〜５ｍｍ、好ましくは１．６〜４．５ｍｍ、さらに好ましくは１．８〜４．０ｍｍの範囲である。例えば、シリンダ−型の場合は、長さは１．５〜４ｍｍ、径は１．５〜４ｍｍ程度であるのが実用的である。球状粒子の場合は、最大粒子径が平均粒子径の１．１〜２．０倍、最小粒子径が平均粒子径の０．７倍以上であるのが実用的である。また、チップの重量は１０〜３０ｍｇ／個の範囲が実用的である。
【０１０２】
また、本発明のポリエステル組成物は、これを射出成形して得られた厚さ５ｍｍの成形板のヘイズが１５％以下、また射出成形して得た厚さ２ｍｍの成形体からの試験片の昇温時の結晶化温度（以下「Ｔｃ１」と称する）が、１５０〜１７２℃の範囲であることが望ましい。成形板のヘイズは、好ましくは１０％以下、さらに好ましくは８％以下であり、また昇温時の結晶化温度（Ｔｃ１）は、好ましくは１５３〜１７０℃、さらに好ましくは１５５〜１６８℃の範囲である。
【０１０３】
成形板のヘイズが１５％を超える場合は，得られた中空成形体の透明性が悪くなり、特に延伸中空成形体の場合には問題となる。また、Ｔｃ１が１７２℃を越える場合は、加熱結晶化速度が非常に遅くなり中空成形体口栓部の結晶化が不十分となり、内容物の漏れの問題が発生する。また、Ｔｃ１が１５０℃未満の場合は、中空成形体の透明性が低下し問題となる場合がある。
【０１０４】
本発明のポリエステル組成物は、使用済みＰＥＴボトルをケミカルリサイクル法によって精製し回収したジメチルテレフタレートやテレフタル酸などの原料を少なくとも出発原料の一部として用いて得たＰＥＴや、使用済みＰＥＴボトルをメカニカルリサイクル法により精製し回収したフレーク状ＰＥＴやチップ状ＰＥＴなどと混合して用いることができる。
【０１０５】
本発明のポリエステル組成物に飽和脂肪酸モノアミド、不飽和脂肪酸モノアミド、飽和脂肪酸ビスアミド、不飽和脂肪酸ビスアミド等を同時に併用することも可能である。
飽和脂肪酸モノアミドの例としては、ラウリン酸アミド、パルミチン酸アミド、ステアリン酸アミド、ベヘン酸アミド等が挙げられる。不飽和脂肪酸モノアミドの例としては、オレイン酸アミド、エルカ酸アミドリシノ−ル酸アミド等が挙げられる。飽和脂肪酸ビスアミドの例としては、メチレンビスステアリン酸アミド、エチレンビスカプリン酸アミド、エチレンビスラウリン酸アミド、エチレンビスステアリン酸アミド、エチレンビスベヘン酸アミド、ヘキサメチレンビスステアリン酸アミド、ヘキサメチレンビスベヘン酸アミド等が挙げられる。また、不飽和脂肪酸ビスアミドの例としては、エチレンビスオレイン酸アミド、ヘキサメチレンビスオレイン酸アミド等が挙げられる。好ましいアミド系化合物は、飽和脂肪酸ビスアミド、不飽和脂肪酸ビスアミド等である。このようなアミド化合物の配合量は、１０ｐｐｂ〜１×１０^５ｐｐｍの範囲である。
【０１０６】
また炭素数８〜３３の脂肪族モノカルボン酸の金属塩化合物、例えばナフテン酸、カプリル酸、カプリン酸、ラウリン酸、ミリスチン酸、パルミチン酸、ステアリン酸、ベヘニン酸、モンタン酸、メリシン酸、オレイン酸、リノ−ル酸等の飽和及び不飽和脂肪酸のリチュウム塩、ナトリウム塩、カリウム塩、マグネシウム塩、カルシウム塩、及びコバルト塩等を同時に併用することも可能である。これらの化合物の配合量は、１０ｐｐｂ〜３００ｐｐｍの範囲である。
【０１０７】
本発明のポリエステル組成物は、中空成形体、トレ−、２軸延伸フイルム等の包装材、金属缶被覆用フイルム等として好ましく用いることが出来る。また、本発明のポリエステル組成物は、多層成形体や多層フイルム等の１構成層としても用いることが出来る。
【０１０８】
本発明のポリエステル組成物は、一般的に用いられる溶融成形法を用いてフィルム、シート、容器、その他の包装材料を成形することができる。また、本発明のポリエステル組成物からなるシ−ト状物を少なくとも一軸方向に延伸することにより機械的強度を改善することが可能である。本発明のポリエステル組成物からなる延伸フィルムは射出成形もしくは押出成形して得られたシート状物を、通常ＰＥＴの延伸に用いられる一軸延伸、逐次二軸延伸、同時二軸延伸のうちの任意の延伸方法を用いて成形される。また圧空成形、真空成形によリカップ状やトレイ状に成形することもできる。
【０１０９】
延伸フィルムを製造するに当たっては、延伸温度は通常は８０〜１３０℃である。延伸は一軸でも二軸でもよいが、好ましくはフィルム実用物性の点から二軸延伸である。延伸倍率は一軸の場合であれば通常１．１〜１０倍、好ましくは１．５〜８倍の範囲で行い、二軸延伸であれば縦方向および横方向ともそれぞれ通常１．１〜８倍、好ましくは１．５〜５倍の範囲で行えばよい。また、縦方向倍率／横方向倍率は通常０．５〜２、好ましくは０．７〜１．３である。得られた延伸フィルムは、さらに熱固定して、耐熱性、機械的強度を改善することもできる。熱固定は通常緊張下、１２０℃〜２４０、好ましくは１５０〜２３０℃で、通常数秒〜数時間、好ましくは数十秒〜数分間行われる。
【０１１０】
中空成形体を製造するにあたっては、本発明のポリエステル組成物から成形したブリフォームを延伸ブロー成形してなるもので、従来ＰＥＴのブロー成形で用いられている装置を用いることができる。具体的には例えば、射出成形または押出成形で一旦プリフォームを成形し、そのままあるいは口栓部、底部を加工後、それを再加熱し、ホットパリソン法あるいはコールドパリソン法などの二軸延伸ブロー成形法が適用される。この場合の成形温度、具体的には成形機のシリンダー各部およびノズルの温度は通常２６０〜３００℃の範囲である。延伸温度ば通常７０〜１２０℃、好ましくは９０〜１１０℃で、延伸倍率は通常縦方向に１．５〜３．５倍、円周方向に２〜５倍の範囲で行えばよい。得られた中空成形体は、そのまま使用できるが、特に果汁飲料、ウーロン茶などのように熱充填を必要とする飲料の場合には一般的に、さらにブロー金型内で熱固定処理を行い、耐熱性を付与して使用される。熱固定は通常、圧空などによる緊張下、１００〜２００℃、好ましくは１２０〜１８０℃で、数秒〜数時間、好ましくは数秒〜数分間行われる。
【０１１１】
また、口栓部に耐熱性を付与するために、射出成形または押出成形により得られたプリフォ−ムの口栓部を遠赤外線や近赤外線ヒ−タ設置オ−ブン内で結晶化させたり、あるいはボトル成形後に口栓部を前記のヒ−タで結晶化させる。
【０１１２】
本発明のポリエステル組成物には、必要に応じて公知の紫外線吸収剤、酸化防止剤、酸素捕獲剤、外部より添加する滑剤や反応中に内部析出させた滑剤、離型剤、核剤、安定剤、帯電防止剤、染料、顔料などの各種の添加剤を配合してもよい。
【０１１３】
また、本発明のポリエステル組成物をフイルム用途に使用する場合には、滑り性、巻き性、耐ブロッキング性などのハンドリング性を改善するために、ポリエステル組成物中に炭酸カルシウム、炭酸マグネシウム、炭酸バリウム、硫酸カルシウム、硫酸バリウム、リン酸リチウム、リン酸カルシウム、リン酸マグネシウム等の無機粒子、蓚酸カルシウムやカルシウム、バリウム、亜鉛、マンガン、マグネシウム等のテレフタル酸塩等の有機塩粒子やジビニルベンゼン、スチレン、アクリル酸、メタクリル酸、アクリル酸またはメタクリル酸のビニル系モノマーの単独または共重合体等の架橋高分子粒子などの不活性粒子を含有させることが出来る。
なお、本発明における、主な特性値の測定法を以下に説明する。
【０１１４】
【実施例】
以下本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定させるものではない。なお、本明細書中における主な特性値の測定法を以下に説明する。
【０１１５】
（１）ポリエステルの極限粘度（ＩＶ）
１，１，２，２−テトラクロルエタン／フェノ−ル（２：３重量比）混合溶媒中３０℃での溶液粘度から求めた。
【０１１６】
（２）ポリエステルのジエチレングリコ−ル含有量（以下［ＤＥＧ含有量」という）
メタノ−ルにより分解し、ガスクロマトグラフィ−によりＤＥＧ量を定量し、全グリコ−ル成分に対する割合（モル％）で表した。
【０１１７】
（３）ポリエステルの環状三量体の含有量（以下「ＣＴ含有量」という）
試料３００ｍｇをヘキサフルオロイソプロパノ−ル／クロロフォルム混合液（容量比＝２／３）３ｍｌに溶解し、さらにクロロフォルム３０ｍｌを加えて希釈する。これにメタノ−ル１５ｍｌを加えてポリマ−を沈殿させた後、濾過する。濾液を蒸発乾固し、ジメチルフォルムアミド１０ｍｌで定容とし、高速液体クロマトグラフ法により環状三量体を定量した。
【０１１８】
（４）ポリエステルのアセトアルデヒド含有量（以下「ＡＡ含有量」という）
試料／蒸留水＝１グラム／２ｃｃを窒素置換したガラスアンプルに入れた上部を溶封し、１６０℃で２時間抽出処理を行い、冷却後抽出液中のアセトアルデヒドを高感度ガスクロマトグラフィ−で測定し、濃度をｐｐｍで表示した。
【０１１９】
（５）ポリエステルの溶融時の環状三量体増加量（△ＣＴ量）
乾燥したポリエステルチップ３ｇをガラス製試験管に入れ、窒素雰囲気下で２９０℃のオイルバスに６０分浸漬させ溶融させる。溶融時の環状三量体増加量は、次式により求める。
溶融時の環状三量体増加量（重量％）＝
溶融後の環状三量体含有量（重量％）−溶融前の環状三量体含有量（重量％）
【０１２０】
（６）ファインの含有量およびフイルム状物含有量の測定
樹脂約０．５ｋｇを、ＪＩＳ−Ｚ８８０１による呼び寸法５．６ｍｍの金網をはった篩（Ａ）と呼び寸法１．７ｍｍの金網をはった篩（直径２０ｃｍ）（Ｂ）を２段に組合せた篩の上に乗せ、テラオカ社製揺動型篩い振トウ機ＳＮＦ−７で１８００ｒｐｍで１分間篩った。この操作を繰り返し、樹脂を合計２０ｋｇ篩った。
前記の篩（Ａ）上に、厚みが約０．５ｍｍ以下のフイルム状物とは別に、２個以上のチップがお互いに融着したものや正常な形状より大きなサイズに切断されたチップ状物が捕捉されている場合は、これらを除去した残りの、厚みが約０．５ｍｍ以下のフイルム状物および篩（Ｂ）の下にふるい落とされたファインは、別々にイオン交換水で洗浄し岩城硝子社製Ｇ１ガラスフィルターで濾過して集めた。これらをガラスフィルターごと乾燥器内で１００℃で２時間乾燥後、冷却して秤量した。再度、イオン交換水で洗浄、乾燥の同一操作を繰り返し、恒量になったことを確認し、この重量からガラスフィルターの重量を引き、ファイン重量およびフイルム状物の重量を求めた。ファイン含有量あるいはフイルム状物含有量は、ファイン重量またはフイルム状物重量／篩いにかけた全樹脂重量、である。これらの値より合計含有量を求める。
【０１２１】
（７）ファインの降温時結晶化温度（Ｔｃ２’）の測定
セイコ−電子工業（株）製の示差走査熱量計（ＤＳＣ）、ＲＤＣ−２２０を用いて測定。（６）において、２０ｋｇのポリエステルから集めたファインを２５℃で３日間減圧下に乾燥し、これから一回の測定に試料１０ｍｇを使用した。室温から２９０℃まで昇温速度２０℃／分の速度で昇温し、２９０℃で３分間保持した後、液体窒素で急冷する。次いで、再度同様の条件で昇温したあと、２９０℃で３分間保持し、２４０℃までは１０℃／分の速度で降温し、さらに室温まで７℃／分の速度で降温した。この降温時に観察される結晶化ピ−ク温度を求め、これを降温時結晶化温度（Ｔｃ２’）とする。測定は、ファインの試料、最大１０ヶについて実施して、これらの降温時結晶化温度（Ｔｃ２’）の平均値を求め、これをファインの降温時結晶化温度（Ｔｃ２’）とする。
【０１２２】
（８）成形体の昇温時の結晶化温度（Ｔｃ１）
セイコ−電子工業株式会社製の示差熱分析計（ＤＳＣ）、ＲＤＣ−２２０で測定。下記（１３）の成形板の２ｍｍ厚みのプレ−トの中央部からの試料１０ｍｇを使用。昇温速度２０度Ｃ／分で昇温し、その途中において観察される結晶化ピ−クの頂点温度を測定し、昇温時結晶化温度（Ｔｃ１）とする。
【０１２３】
（９）ポリエステルチップの平均密度およびプリフォ−ム口栓部の密度
硝酸カルシュウム／水混合溶液の密度勾配管で３０℃で測定した。
【０１２４】
（１０）ヘイズ（霞度％）およびヘイズ斑
下記（１３）の成形体（肉厚５ｍｍ）および（１４）の中空成形体の胴部（肉厚約０．４ｍｍ）より試料を切り取り、日本電色（株）製ヘイズメ−タ−、ｍｏｄｅｌＮＤＨ２０００で測定。また、１０回連続して成形した成形板（肉厚５ｍｍ）のヘイズを測定し、ヘイズ斑は下記により求めた。
ヘイズ斑＝ヘイズの最大値／ヘイズの最小値
【０１２５】
（１１）プリフォ−ム口栓部の加熱による密度上昇
プリフォ−ム口栓部を自家製の赤外線ヒ−タ−によって１８０秒間熱処理し、天面から試料を採取し密度を測定した。
【０１２６】
（１２）段付成形板の成形
本特許記載にかかる段付成形板の成形においては、減圧乾燥機を用いて１４０℃で１６時間程度減圧乾燥したポリエステルチップを名機製作所製射出成形機Ｍ−１５０Ｃ−ＤＭ型射出成形機により図１、図２に示すようにゲート部（Ｇ）を有する、２ｍｍ〜１１ｍｍ（Ａ部の厚み＝２ｍｍ、Ｂ部の厚み＝３ｍｍ、Ｃ部の厚み＝４ｍｍ、Ｄ部の厚み＝５ｍｍ、Ｅ部の厚み＝１０ｍｍ、Ｆ部の厚み＝１１ｍｍ）の厚さの段付成形板を射出成形した。
【０１２７】
ヤマト科学製真空乾燥器ＤＰ６１型を用いて予め減圧乾燥したポリエステルチップを用い、成形中にチップの吸湿を防止するために、成形材料ホッパー内は乾燥不活性ガス（窒素ガス）パージを行った。Ｍ−１５０Ｃ−ＤＭ射出成形機による可塑化条件としては、フィードスクリュウ回転数＝７０％、スクリュウ回転数＝１２０ｒｐｍ、背圧０．５ＭＰａ、シリンダー温度はホッパー直下から順に４５℃、２５０℃、以降ノズルを含め２９０℃に設定した。射出条件は射出速度及び保圧速度は２０％、また成形品重量が１４６±０．２ｇになるように射出圧力及び保圧を調整し、その際保圧は射出圧力に対して０．５ＭＰａ低く調整した。
射出時間、保圧時間はそれぞれ上限を１０秒、７秒，冷却時間は５０秒に設定し、成形品取出時間も含めた全体のサイクルタイムは概ね７５秒程度である。
金型には常時、水温１０℃の冷却水を導入し温調するが、成形安定時の金型表面温度は２２℃前後である。
【０１２８】
成形品特性評価用のテストプレートは、成形材料導入し樹脂置換を行った後、成形開始から１１〜１８ショット目の安定した成形品の中から任意に選ぶものとした。
２ｍｍ厚みのプレート（図１のＡ部）は昇温時の結晶化温度（Ｔｃ１）測定、５ｍｍ厚みのプレート（図１のＤ部）はヘイズ（霞度％）測定、に使用する。
【０１２９】
（１３）中空成形体の成形
ポリエステルを脱湿空気を用いた乾燥機で乾燥し、各機製作所製Ｍ−１５０Ｃ（ＤＭ）射出成形機により樹脂温度２９０℃でプリフォームを成形した。このプリフォームの口栓部を自家製の口栓部結晶化装置で加熱結晶化させた。次にこの予備成形体をＣＯＲＰＯＰＬＡＳＴ社製のＬＢ−０１Ｅ成形機で縦方法に約２．５倍、周方向に約３．８倍の倍率に二軸延伸ブローし、引き続き約１５０℃に設定した金型内で約７秒間熱固定し、容量が２０００ｃｃの容器（胴部肉厚０．４５ｍｍ）を成形した。延伸温度は１００℃にコントロールした。
【０１３０】
（１４）中空成形体からの内容物の漏れ評価
前記（１３）で成形した中空成形体に９０℃の温湯を充填し、キャッピング機によりキャッピングをしたあと容器を倒し放置後、内容物の漏洩を調べた。また、キャッピング後の口栓部の変形状態も調べた。
【０１３１】
（１５）チップ化工程の冷却水および水処理工程の導入水中のナトリウム含有量、カルシウム含有量、マグネシウム含有量および珪素含有量
粒子除去およびイオン交換済みの冷却水または導入水を採取し、岩城硝子社製１Ｇ１ガラスフィルタ−で濾過後、濾液を原子吸光法、ＩＣＰ法、ＩＰＣ−ＭＳ法で測定。
【０１３２】
（１６）チップ化工程の冷却水中、および水処理工程の導入水中およびリサイクル水中の粒子数の測定
チップ化工程の冷却水、粒子除去およびイオン交換済みの導入水、または濾過装置（５）および吸着塔（８）で処理したリサイクル水を光遮断法による粒子測定器である株式会社セイシン企業製のＰＡＣ　１５０を用いて測定し、粒子数を個／１０ｍｌで表示した。
【０１３３】
（１７）ポリエステルチップと接触する気体中の粒子数の測定
気体を強制的に送るための送風機等によって送られ、気体清浄装置を通過した気体をチップと接触する前に気体本流と分岐して粒子測定器に導入して測定する。５回測定を繰返し、平均値を求め、気体１立方フィート当たりの個数を計算する。
粒子測定器としては、リオン株式会社製の光散乱式粒子測定器、ＫＣ−０１Ｂを用いた。
【０１３４】
（実施例１）
予め反応物を含有している第１エステル化反応器に、高純度テレフタル酸とエチルグリコ−ルとのスラリ−を連続的に供給し、撹拌下、約２５０℃、０．５ｋｇ／ｃｍ^２Ｇで平均滞留時間３時間反応を行った。この反応物を第２エステル化反応器に送付し、撹拌下、約２６０℃、０．０５ｋｇ／ｃｍ^２で所定の反応度まで反応を行った。また、結晶性二酸化ゲルマニウムを水に加熱溶解し、これにエチレングリコ−ルを添加加熱処理した触媒溶液および燐酸のエチレングリコ−ル溶液を、別々にこの第２エステル化反応器に連続的に供給した。このエステル化反応生成物を連続的に第１重縮合反応器に供給し、撹拌下、約２６５℃、２５ｔｏｒｒで１時間、次いで第２重縮合反応器で撹拌下、約２６５℃、３ｔｏｒｒで１時間、さらに最終重縮合反応器で撹拌下、約２７５℃、０．５〜１ｔｏｒｒで１時間重縮合させた。溶融重縮合プレポリマ−の極限粘度は０．５６ｄｌ／ｇであった。
【０１３５】
溶融重縮合反応物を冷却水（ナトリウム含有量が０．０２ｐｐｍ、マグネシウム含有量が０．０２ｐｐｍ、カルシウム含有量が０．０２ｐｐｍ、珪素含有量が０．０８ｐｐｍ）で冷却しながらチップ化後、約５０℃以下のチップを貯蔵用タンクへ輸送し、次いで振動式篩分工程および気流分級工程によってファインおよびフイルム状物を除去することにより、ファイン含有量を約５０ｐｐｍ以下とした。次いでバケット式コンベヤー輸送方式によって結晶化装置に送り、窒素ガス流通下に約１５５℃で３時間連続的に結晶化し、次いで塔型固相重合器に投入し、窒素ガス流通下、約２０７℃で連続的に約１５時間、固相重合し、固相重合ポリエステルを得た。固相重合後、篩分工程およびファイン等除去工程で連続的に処理しファインやフイルム状物を除去し、貯蔵タンクに保管した。
【０１３６】
このポリエステルを次のようにして水処理した。ポリエステルチップの水処理には、図３に示す装置を用い、処理槽上部の原料チップ供給口（１）、処理槽の処理水上限レベルに位置するオ−バ−フロ−排出口（２）、処理槽下部のポリエステルチップと処理水の混合物の排出口（３）、このオ−バ−フロ−排出口から排出された処理水と、処理槽から排出された処理水と、処理槽下部の排出口から排出された水切り装置（４）を経由した処理水が、濾材が紙製の連続式フィルタ−である微粉除去装置（５）を経由して再び水処理槽へ送られる配管（６）、これらの微粉除去済み処理水の導入口（７）、微粉除去済み処理水中のアセトアルデヒドを吸着処理させる吸着塔（８）、及び新しいイオン交換水の導入口（９）を備えた内容量約５０ｍ^３リットルの塔型の処理槽を使用した。
【０１３７】
前記の固相重合ＰＥＴチップを気流分級工程および振動式篩分工程によりファインおよびフイルム状物を除去処理後、処理水温度９５℃にコントロ−ルされた水処理槽へ５０ｋｇ／時間の速度で処理槽上部の供給口（１）から連続投入して水処理し、処理槽下部の排出口（３）からＰＥＴチップとして５０ｋｇ／時間の速度で処理水と共に連続的に抜き出した。上記処理装置のイオン交換水導入口（９）の手前で採取した導入水中の粒径１〜２５μｍの粒子含有量は約１９００個／１０ｍｌ、ナトリウム含有量が０．０２ｐｐｍ、マグネシウム含有量が０．０２ｐｐｍ、カルシウム含有量が０．０３ｐｐｍ、珪素含有量が０．０９ｐｐｍであり、また濾過装置（５）および吸着塔（８）で処理後のリサイクル水の粒径１〜４０μｍの粒子数は約１００００個／１０ｍｌであった。
【０１３８】
水処理後、振動式篩工程および気流分級工程でファイン等の除去処理を行った。
得られたＰＥＴ組成物の極限粘度は０．７４デシリットル／グラム、ＤＥＧ含有量は２．７モル％、環状三量体の含有量は０．３２重量％、環状三量体増加量は０．１２重量％、平均密度は１．４０２１ｇ／ｃｍ^３、ＡＡ含有量は３．２ｐｐｍ、ファイン含有量は約５０ｐｐｍであった。また、ファインの降温時結晶化温度（Ｔｃ２’）は１８０℃であった。また原子吸光分析により測定したＧｅ残存量は４８ｐｐｍ、またＰ残存量は３１ｐｐｍであった。
【０１３９】
得られたＰＥＴ組成物について前記（１２）および（１３）の方法によって成形板および二軸延伸成形ボトルによる評価を実施した。結果を表１に示す。
成形板のヘイズは４．１％、成形板ヘイズ斑は０．２％、成形板のＴｃ１は１６９℃、口栓部の密度は１．３７８ｇ／ｃｍ３、口栓部密度偏差は０．００２ｇ／ｃｍ３と問題のない値であった。また、内容物の漏れ試験でも、問題はなく、口栓部の変形もなかった。得られたボトルの胴部ヘイズは１．０％と良好であった。ボトルのＡＡ含有量は１６．８ｐｐｍと問題のない値であった。また、５０００本以上の連続延伸ブロ−成形を実施したが、金型汚れは認められず、問題がなかった。
【０１４０】
なお、製造工程における溶融重合プレポリマ−チップや固相重合チップ、水処理チップの輸送は全てバケット式コンベヤー輸送方式により、反応器や貯層からのチップの抜き出しは全てスクリュウ式フィ−ダ−を用いた。
また溶融重縮合ＰＥＴチップや固相重合ＰＥＴチップを輸送用容器や保管用容器に充填、貯蔵するまでにチップと接触する空気として、ＪＩＳ　Ｂ　９９０８（１９９１）の形式３のＰＥＴ不織布製フィルタユニットを装着した空気清浄機及びＪＩＳ　Ｂ　９９０８（１９９１）の形式１の粒子捕集率９９％以上のＨＥＰＡフィルタユニットを装着した空気清浄機で濾過した空気（粒径０．３〜５μｍの粒子数は約５００個／立方フィ−ト）を使用した。実施例２、実施例３、および比較例１でも同様にした。
【０１４１】
（実施例２）
結晶性二酸化ゲルマニウムのエチレングリコール溶液の替わりに、チタン酸テトライソプロピルのエチレングリコ−ル溶液と結晶性二酸化ゲルマニウムのエチレングリコ−ル溶液を用い、これらの触媒溶液を個別に、第２エステル化反応器に連続的に供給し、次いで、燐酸のエチレングリコ−ル溶液を第２エステル化反応器から第１重縮合反応器への輸送配管中に連続的に供給する以外は実施例１と同様にしてエステル化及び重縮合を実施し、次いで、実施例１と同様の条件下でチップ化し、ＩＶ０．５５ｄｌ／ｇのポリエチレンテレフタレ−ト・プレポリマ−を得た。
次いで、実施例１と同様にして固相重合及び水処理を行った。
【０１４２】
得られたＰＥＴ組成物の極限粘度は０．７４デシリットル／グラム、ＤＥＧ含有量は２．７モル％、環状三量体の含有量は０．３２重量％、環状三量体増加量は０．２６重量％、平均密度は１．４０２１ｇ／ｃｍ３、ＡＡ含有量は３．２ｐｐｍ、ファイン含有量は約５０ｐｐｍ、またその降温時結晶化温度（Ｔｃ２’）は１７９℃であった。原子吸光分析により測定したＧｅ残存量は１８ｐｐｍ、Ｔｉ残存量は０．６ｐｐｍ、またＰ残存量は１０ｐｐｍであった。
【０１４３】
得られたＰＥＴ組成物について前記（１２）および（１３）の方法によって成形板および二軸延伸成形ボトルによる評価を実施した。結果を表１に示す。成形板のヘイズは４．０％、成形板のＴｃ１は１７０℃、口栓部の密度は１．３７７ｇ／ｃｍ３と問題のない値であった。また、内容物の漏れ試験でも、問題はなく、口栓部の変形もなかった。得られたボトルの胴部ヘイズは１．０％良好であった。ボトルのＡＡ含有量は１８．７ｐｐｍと問題のない値であった。また、５０００本以上の連続延伸ブロ−成形を実施したが、金型汚れは認められず、問題がなかった。
【０１４４】
なお、製造工程における溶融重縮合チップの輸送及び抜き出しのみ、実施例１と同様の装置を用いて同様の方法で行った。固相重合ＰＥＴチップの輸送は低密度輸送方式によった。
【０１４５】
（実施例３）
結晶性二酸化ゲルマニウムのエチレングリコール溶液の替わりに、結晶性二酸化ゲルマニウムのエチレングリコ−ル溶液と塩基性酢酸アルミニウムの水／エチレングリコ−ル溶液を用い、これらの触媒溶液と燐酸のエチレングリコ−ル溶液を、別々に第２エステル化反応器に連続的に供給する以外は実施例１と同様にしてエステル化及び重縮合を実施し、次いで、実施例１と同様の条件下でチップ化し、ＩＶ０．５６ｄｌ／ｇのポリエチレンテレフタレ−ト・プレポリマ−を得た。次いで、実施例１と同様にして固相重合及び水処理を行った。なおファイン除去能力は強化した。
【０１４６】
得られたＰＥＴ組成物の極限粘度は０．７４デシリットル／グラム、ＤＥＧ含有量は２．７モル％、ＡＡ含有量は３．３ｐｐｍ、環状三量体の含有量は０．３３重量％、環状三量体の増加量は０．３１重量％、平均密度は１．４０２２ｇ／ｃｍ３、ファイン含有量は１２ｐｐｍ、またその降温時結晶化温度（Ｔｃ２’）は１７７℃であり、またフイルム状物はなかった。
【０１４７】
得られたＰＥＴ組成物について前記（１２）および（１３）の方法によって成形板および二軸延伸成形ボトルによる評価を実施した。結果を表１に示す。
成形板のヘイズは３．９％、成形板ヘイズ斑は０．２％、成形板のＴｃ１は１７０℃であった。ボトル口栓部の密度は１．３８０ｇ／ｃｍ３、口栓部密度偏差は０．００２ｇ／ｃｍ３と問題のない値であり、ボトルの胴部ヘイズは１．０％と良好であった。また、内容物の漏れ試験でも、問題はなく、口栓部の変形もなかった。ボトルのＡＡ含有量は１８．５ｐｐｍと問題のない値であった。また、５０００本以上の連続延伸ブロ−成形を実施したが、金型汚れは認められず、問題がなかった。
【０１４８】
なお、製造工程における溶融重合プレポリマ−チップや固相重合チップ、水処理チップの輸送は、実施例１と同様にして行った。
【０１４９】
（実施例４）
異種樹脂製ボトルを選別除去後、ラベル及びキャップを取り外した使用済みポリエチレンテレフタレートボトルを粉砕、水洗して得た回収フレークを解重合触媒の存在下にエチレングリコールで解重合し、次いでメタノールでエステル交換反応して得られた粗テレフタル酸ジメチルを蒸留精製し、この様にして得た精製テレフタル酸ジメチルを加水分解して高純度のテレフタル酸を得た。
【０１５０】
前記テレフタル酸及びエチレングリコール（バージン品）のスラリー（エチレングリコール／テレフタル酸モル比＝１．６）を、ビス（ヒドロキシエチル）テレフタレートが仕込まれ、温度２５０℃、常圧に保持されたエステル化反応槽に供給し、副生する水を系外に溜出させながら４時間でエステル化反応を行い、このエステル化反応生成物の１００ｋｇを重縮合槽に移送した。
【０１５１】
引き続いて、エステル化反応生成物が移送された前記重縮合槽に、複数の重縮合触媒供給配管より、実施例１で用いたのと同じ結晶性二酸化ゲルマニウムのエチレングリコ−ル溶液および燐酸のエチレングリコ−ル溶液を、添加した後、系内を１時間かけて２５０℃から２７５℃まで昇温すると共に、１時間で常圧から３５０Ｐａとし、引き続き１５０Ｐａの減圧下、２７６℃で、得られる樹脂の固有粘度が０．５６ｄｌ／ｇとなる時間溶融重縮合させた。
【０１５２】
重縮合槽の底部に設けられた抜き出し口からストランド状に抜き出して、実施例１で用いたと同質のイオン交換水で冷却しながらチップ化してチップ温度を約５０℃以下とし、次いで振動式篩分機によってファインおよびフイルム状物を除去することにより、ファイン含有量を約５０ｐｐｍ以下とした。
【０１５３】
引き続いて、前記で得られたポリエステル樹脂チップを、約１６０℃に保持された攪拌流動式結晶化機で結晶化させた後、充填塔式固相重合塔に移し、窒素流通下２１０℃で固相重合し、次いで篩分工程およびファイン除去工程で処理しファインを除去し、ファイン含有量を約５０ｐｐｍとした。Ｇｅ残存量は４５ｐｐｍ、またＰ残存量は２５ｐｐｍであった。
【０１５４】
次いで実施例１と同様にして水処理を行なった。
得られたＰＥＴ組成物（ＰＥＴのＩＶは０．７４デシリットル／グラム、ＤＥＧ含有量は３．１モル％、ＡＡ含有量は４．５ｐｐｍ、環状３量体の含有量は０．３５重量％、ファイン含有量は約５０ｐｐｍ、フイルム状物は含有せず、またファインのＴｃ２’は１８３℃）について成形板及び二軸延伸成形ボトルによる評価を実施した。
【０１５５】
成形板のヘイズは８．６％、成形板ヘイズ斑は０．３％、成形板のＴｃ１は１５８℃であった。ボトル口栓部の密度は１．３８２ｇ／ｃｍ３、口栓部密度偏差は０．００３ｇ／ｃｍ３と問題のない値であり、ボトルの胴部ヘイズは１．４％と良好であった。
また、内容物の漏れ試験でも、問題はなく、口栓部の変形もなかった。ボトルのＡＡ含有量は２１．６ｐｐｍ、と問題のない値であった。
なお、製造工程における溶融重合プレポリマ−チップや固相重合チップなどの輸送は、実施例１と同様にして行った。
【０１５６】
（比較例１）
結晶性二酸化ゲルマニウムの添加量を増やす以外は実施例１と同様にして溶融重縮合したプレポリマ−を、同水質の冷却水で冷却しながらチップ化してチップ温度を約６５℃とし、ファイン等の除去処理を行わずに低密度輸送方式によって一時的な貯蔵用サイロに輸送した。次いでこれを回転式タンブラ−に投入し、回転しながら減圧下において１４０℃で結晶化後、２１５℃で固相重合した。固相重合装置への輸送及び固相重合後の輸送は全て低密度輸送方式によった。
得られたＰＥＴ組成物を実施例１と同一条件で水処理を実施した。溶融重縮合から水処理後までの全ての工程においてファイン等の除去装置で処理を行なわなかった。
【０１５７】
得られたＰＥＴ、これを成形した成形板および二軸延伸成形ボトルの特性を表１に示す。得られたボトルの透明性は悪く、また口栓部の変形、及び内容物の漏洩を調べたが、内容物の漏れが激しく、問題であった。
【０１５８】
【表１】

【０１５９】
【発明の効果】
本発明のポリエステル組成物によれば、溶融成形時の結晶化コントロ−ル性、長時間連続成形性に優れており、それから得られた中空成形体、シ−ト状物および延伸フイルムは、透明性、耐熱寸法安定性が優れ、特に、中空成形体の口栓部収縮率が適正な範囲であり、液体容器としたときに残留異味、異臭が発生しにくい。
【図面の簡単な説明】
【図１】実施例において使用した段付成形板の平面図
【図２】図１の段付成形板の側面図
【図３】実施例で用いた水処理装置の概略図。
【符号の説明】
１　原料チップ供給口
２　オ−バ−フロ−排出口
３　ポリエステルチップと処理水との排出口
４　水切り装置
５　ファイン除去装置
６　配管
７　リサイクル水または／およびイオン交換水の導入口
８　吸着塔
９　イオン交換水導入口[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polyester composition and a hollow molded article, a sheet-like material, and a stretched film comprising the same, particularly, a polyester composition having excellent crystallization controllability during melt molding and long-term continuous moldability, and The present invention relates to a molded article, a sheet, and a stretched film having excellent transparency and heat-resistant dimensional stability.
[0002]
[Prior art]
Polyesters in which the main repeating unit is ethylene terephthalate (hereinafter sometimes abbreviated as PET resin) are characterized by their excellent transparency, mechanical strength, heat resistance, gas barrier properties, and other properties, and are characterized by carbonated beverages, juices, and mineral water. Is widely used as a material for such containers. In these applications, polyester bottles are hot-filled with beverages that have been sterilized at high temperatures, or beverages are sterilized at high temperatures after filling, but ordinary polyester bottles shrink during such hot-filling processes. However, deformation occurs and becomes a problem. As a method for improving the heat resistance of the polyester bottle, a method has been proposed in which the crystallinity of the bottle is increased by heat treatment of the bottle stopper, or the stretched bottle is heat-fixed. In particular, when the crystallization of the plug portion is insufficient or when the degree of crystallization varies widely, the sealing performance with the cap is deteriorated and the contents may leak.
[0003]
Further, in order to improve the heat resistance of the bottle body, for example, as shown in Patent Document 1, a method of performing heat treatment at a high temperature of a stretch blow mold is adopted (see Patent Document 1). In the case of bottles used for applications subject to heat sterilization at high temperatures, if a PET resin with a high crystallization rate is used, only a heat-treated bottle with poor transparency and large fluctuations in the crystallinity of the plug will be obtained. I can't. In particular, when a defective product generated in a molding factory or a recovered product of a used bottle is reused as a part of the bottle molding material, the crystallization characteristics of the virgin raw material become a problem. Such a problem frequently occurs in a large-sized bottle having a capacity of 1.5 liters or more because the wall thickness is large.
[0004]
Further, when a large number of bottles are continuously formed using the same mold by such a method, the bottle obtained with long-time operation is whitened and the transparency is reduced, so that only bottles having no commercial value can be obtained. . It has been found that this is because deposits caused by the PET resin adhere to the mold surface, resulting in mold stains, and the mold stains are transferred to the surface of the bottle. In particular, in recent years, the molding speed has been increased for the purpose of cost reduction during bottle production, and mold contamination has become a more serious problem in terms of productivity.
[0005]
Further, in the case of a content liquid that requires hot filling such as a fruit juice beverage, a method of heat-treating the plug portion of a preform or a molded bottle to crystallize is generally used (Patent Document 2 and Patent Document 2). Patent Document 3). Such a method, that is, a method of improving the heat resistance by heat treatment of the plug portion and the shoulder portion, the time and temperature for the crystallization treatment greatly affect the productivity, and the crystal can be treated at a low temperature and in a short time. It is preferable that the PET resin has a high conversion rate. On the other hand, the body is required to be transparent even when subjected to a heat treatment at the time of molding so as not to deteriorate the color tone of the filler, and the plug and the body need contradictory characteristics.
[0006]
Various proposals have been made to solve such a problem. For example, there are a method of adding an inorganic nucleating agent such as kaolin and talc to polyethylene terephthalate (see Patent Documents 4 and 5) and a method of adding an organic nucleating agent such as a montanic acid wax salt (see Patent Documents 6 and 7). However, these methods involve the generation of foreign matter and cloudiness, and have problems in practical use. In addition, a method of inserting a heat-resistant resin piece into the plug portion has been proposed (see Patent Documents 8 and 9), but the productivity of the bottle is poor and there is a problem in recyclability.
[0007]
In order to solve such a problem of mold contamination, a method of reducing a cyclic trimer, which is a main component of deposits on the mold surface, by solid-phase polymerization of a PET resin in advance has been performed. In this method, however, the effect is insufficient because the cyclic trimer is regenerated when the preform is formed by remelting. Further, a method is disclosed in which a polyester resin is treated with water at 90 to 110 ° C. to suppress the activity of a catalyst and to control the generation of a cyclic trimer during preform molding (see Patent Document 10). However, there is a problem that sufficient treatment is required to reduce mold contamination at the time of molding, resulting in an increase in cost. In addition, although the mold contamination is reduced by the above method, there is a problem that only a bottle having poor transparency may be obtained in some cases, and a solution is awaited.
[0008]
[Patent Document 1]
JP-B-59-6216
[Patent Document 2]
JP-A-55-79237
[Patent Document 3]
JP-A-58-110221
[Patent Document 4]
JP-A-56-2342
[Patent Document 5]
JP-A-56-21832
[Patent Document 6]
JP-A-57-125246
[Patent Document 7]
JP-A-57-207639
[Patent Document 8]
JP-A-61-259946
[Patent Document 9]
JP-A-2-26938
[Patent Document 10]
Japanese Patent Publication No. 3-47830
[0009]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems of the prior art, and provides a polyester composition excellent in crystallization controllability during melt molding and long-term continuous moldability, and transparency and heat-resistant dimensional stability obtained therefrom. In particular, a hollow molded body, a sheet-like material, and a stretched film in which the shrinkage rate of the plug portion of the hollow molded body is in an appropriate range and the resulting molded article is less likely to generate a residual off-flavor and an unpleasant odor. The purpose is to provide.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the polyester composition of the present invention comprises polyester chips whose main repeating unit is ethylene terephthalate, and 0.1 to 5000 ppm of fine polyester having the same composition as the polyester chips. A polyester composition, wherein the polyester fine has a crystallization temperature (Tc2 ′) of 195 ° C. or less as measured by DSC (differential scanning calorimetry), and the polyester composition is heated at a temperature of 290 ° C. A polyester composition characterized in that the amount of the cyclic trimer increased by melting for 0.5 minute is 0.50% by weight or less.
[0011]
In this case, the content of the film having the same composition as that of the polyester chips may be 10 ppm or less.
Here, fine means a fine powder of polyester which has passed through a sieve provided with a wire mesh having a nominal size of 1.7 mm according to JIS-Z8801, and film-like material means a wire mesh having a nominal size of 5.6 mm according to JIS-Z8801. A film having a thickness of about 0.5 mm or less after removing two or more chips from the polyester remaining on the screened sieve or fusing chips that have been cut larger than the normal shape. And their contents are measured by the following measuring methods.
In addition, as described below, the crystallization temperature (Tc2 ′) of the fine at the time of cooling is measured by a differential scanning calorimeter (DSC).
[0012]
In this case, the amount of increase of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes can be 0.50% by weight or less.
In this case, the cyclic trimer content can be 0.70% by weight or less.
In this case, in the chipping step after the melt polycondensation, the content of sodium, the content of magnesium, the content of silicon, and the content of calcium in the cooling water were N, M, S, and C, respectively. In this case, the polyester may be a chip formed using cooling water satisfying at least one of the following (1) to (4).
N ≦ 1.0 (ppm) (1)
M ≦ 0.5 (ppm) (2)
S ≦ 2.0 (ppm) (3)
C ≦ 1.0 (ppm) (4)
[0013]
Further, the polyester composition of the present invention is obtained by further blending 0.1 ppb to 50,000 ppm of at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, and a polyacetal resin with the polyester composition described above. It is characterized.
[0014]
In this case, the hollow molded article may be formed by molding the polyester composition described above.
In this case, the sheet-like material may be obtained by molding the above-described polyester composition.
Furthermore, in this case, the stretched film can be formed by stretching the sheet-like material in at least one direction.
[0015]
The polyester composition of the present invention hardly causes mold stains during molding, has excellent crystallization controllability of the plug portion, and has excellent transparency, heat resistance, mechanical properties, residual off-flavor, and off-flavor. To give a hollow molded article, a sheet-like material or a stretched film which is low in fragrance and excellent in fragrance retention.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the polyester composition of the present invention and hollow molded articles, sheets and stretched films made thereof will be described in detail.
The polyester according to the present invention is a polyester whose main repeating unit is ethylene terephthalate, preferably a linear polyester containing ethylene terephthalate unit in an amount of 85 mol% or more, and more preferably 90 mol% or more. And particularly preferably a linear polyester containing at least 95% mol.
[0017]
Examples of the dicarboxylic acid used as a copolymer component when the polyester is a copolymer include isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, and diphenoxyethanedicarboxylic acid. Aromatic dicarboxylic acids such as acids and functional derivatives thereof, p-oxybenzoic acid, oxyacids such as oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, aliphatic dicarboxylic acids such as glutaric acid and Examples thereof include functional derivatives thereof, aliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, and functional derivatives thereof.
[0018]
Glycols as copolymer components used when the polyester is a copolymer include diethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, neopentyl glycol and the like. Aliphatic glycols such as aliphatic glycols and cyclohexanedimethanol, aromatic glycols such as bisphenol A, alkylene oxide adducts of bisphenol A, polyethylene glycol and polybutylene And polyalkylene glycols such as glycols.
[0019]
Examples of the polyfunctional compound as a copolymer component used when the polyester is a copolymer include trimellitic acid and pyromellitic acid as acid components, and glycerin as a glycol component. And pentaerythritol. The amount of the above-mentioned copolymer component to be used must be such that the polyester maintains a substantially linear shape. Further, a monofunctional compound such as benzoic acid or naphthoic acid may be copolymerized.
[0020]
The polyester is obtained by directly reacting terephthalic acid with ethylene glycol and, if necessary, the above-mentioned copolymer component to distill off water and esterify the mixture. Then, as a polycondensation catalyst, an antimony compound, a germanium compound, an aluminum compound or titanium is used. A direct esterification method in which one or more compounds selected from compounds are subjected to polycondensation under reduced pressure, or dimethyl terephthalate and ethylene glycol and, if necessary, the above copolymerization component in the presence of a transesterification catalyst After the methyl alcohol is distilled off and transesterified, one or more compounds selected from an antimony compound, a germanium compound, a titanium compound and an aluminum compound are used as a polycondensation catalyst, mainly under reduced pressure. It is produced by a transesterification method in which polycondensation is performed.
[0021]
Examples of the starting materials dimethyl terephthalate, terephthalic acid or ethylene glycol include dimethyl terephthalate of virgin derived from para-xylene, ethylene glycol derived from terephthalic acid or ethylene, and methanol from used PET bottles. Recovered raw materials such as dimethyl terephthalate, terephthalic acid, bishydroxyethyl terephthalate, or ethylene glycol recovered by a chemical recycling method such as decomposition or ethylene glycol decomposition can also be used as at least a part of the starting materials. It goes without saying that the quality of the recovered material must be purified to a purity and quality according to the purpose of use.
[0022]
Further, solid-state polymerization may be performed to increase the molecular weight of the polyester resin and reduce the acetaldehyde content. In order to promote crystallization before solid-phase polymerization, the molten polycondensed polyester may be heated and then crystallized after moisture absorption, or steam may be directly blown onto the polyester chip to be heated and crystallized.
[0023]
First, the polyester to be subjected to solid-state polymerization is pre-crystallized by heating at a temperature of 100 to 210 ° C. for 1 to 5 hours under an inert gas or under reduced pressure or under an atmosphere of steam or an inert gas containing steam. You. Then, solid-state polymerization is performed at a temperature of 190 to 230 ° C. for 1 to 30 hours under an inert gas atmosphere or under reduced pressure.
[0024]
The melt polycondensation reaction may be performed in a batch reactor or a continuous reactor. In any of these methods, the melt polycondensation reaction may be performed in one stage or may be performed in multiple stages. The solid-state polymerization reaction can be performed in a batch-type apparatus or a continuous-type apparatus as in the melt polycondensation reaction. The melt polycondensation and the solid phase polymerization may be performed continuously or may be performed separately.
[0025]
Examples of the antimony compound used in the production of the polyester according to the present invention include antimony trioxide, antimony acetate, antimony tartrate, antimony tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, triphenylantimony and the like. Can be The antimony compound is added so that the residual amount of antimony in the resulting polymer is in the range of 50 to 250 ppm.
[0026]
Examples of the germanium compound used for producing the polyester according to the present invention include amorphous germanium dioxide, crystalline germanium dioxide, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, and germanium tetra-n-. Butoxide, germanium phosphite and the like. When a germanium compound is used, the amount of the germanium compound used is 5 to 150 ppm, preferably 10 to 100 ppm, more preferably 15 to 70 ppm as the amount of germanium remaining in the polyester.
[0027]
Examples of the titanium compound used for producing the polyester according to the present invention include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate and tetra-n-butyl titanate. -Titanium acetate, titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, titanyl calcium oxalate, titanyl strontium oxalate, etc., titanyl oxalate compounds, titanium trimellitate, titanium sulfate, chloride Titanium, hydrolyzate of titanium halide, titanium oxalate, titanium fluoride, potassium hexafluorotitanate, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate And the like. The titanium compound is added so that the amount of titanium remaining in the resulting polymer is in the range of 0.1 to 10 ppm.
[0028]
As the aluminum compound used in the production of the polyester according to the present invention, specifically, aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate Carboxylate such as aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate, aluminum salicylate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride, aluminum nitrate, aluminum sulfate, aluminum carbonate, phosphorus Inorganic acid salts such as aluminum phosphate, aluminum phosphonate, aluminum methoxide, aluminum ethoxide, aluminum n-propoxa , Aluminum iso-propoxide, aluminum n-butoxide, aluminum alkoxide such as aluminum t-butoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethyl acetoacetate, aluminum chelate compounds such as aluminum ethyl acetoacetate diiso-propoxide, Examples thereof include organoaluminum compounds such as trimethylaluminum and triethylaluminum, and partial hydrolysates thereof, and aluminum oxide. Of these, carboxylate, inorganic acid salt and chelate compound are preferred, and among these, basic aluminum acetate, aluminum lactate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride and aluminum acetylacetonate are particularly preferred. preferable. The aluminum compound is added so that the residual amount of aluminum in the resulting polymer is in the range of 5 to 200 ppm.
[0029]
These catalyst compounds can be used, for example, as an ethylene glycol solution during the transesterification step or at any stage from the end of the transesterification reaction to the start of the polycondensation reaction, or during the esterification step or after the end of the esterification reaction to the start of the polycondensation reaction. It can be added at any stage.
[0030]
Further, the polyester composition of the present invention may contain at least one metal compound selected from the group consisting of alkali metal compounds and alkaline earth metal compounds. The alkali metal or alkaline earth metal is preferably at least one selected from lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, and barium. More preferred. When an alkali metal or a compound thereof is used, it is particularly preferable to use lithium, sodium and potassium. Examples of the alkali metal or alkaline earth metal compounds include, for example, saturated aliphatic carboxylate such as formic acid, acetic acid, propionic acid, butyric acid, and oxalic acid, and unsaturated aliphatic carboxylate such as acrylic acid and methacrylic acid. Aromatic carboxylate such as benzoic acid, halogen-containing carboxylate such as trichloroacetic acid, hydroxycarboxylate such as lactic acid, citric acid, salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as oxyhydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, and bromic acid; and organic sulfonic acid salts such as 1-propanesulfonic acid, 1-pentanesulfonic acid, and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butyl Alkoxides such as alkoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like. The alkali metal compound or alkaline earth metal compound is added so that the residual amount of these elements in the produced polymer is in the range of 1 to 50 ppm.
[0031]
These alkali metal compounds and alkaline earth metal compounds can be added to the reaction system at any stage of the polymerization reaction. For example, it can be added to the reaction system before the start of the esterification reaction or the transesterification reaction and at any stage during the reaction, immediately before the start of the polycondensation reaction, or at any stage during the polycondensation reaction.
[0032]
The above alkali metal compound or alkaline earth metal compound is added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution or the like.
[0033]
Furthermore, the polyester composition of the present invention contains a metal compound containing at least one element selected from the group consisting of silicon, manganese, iron, cobalt, zinc, gallium, strontium, zirconium, tin, tungsten, and lead. May be.
These metal compounds include saturated aliphatic carboxylate such as acetate of these elements, unsaturated aliphatic carboxylate such as acrylate, aromatic carboxylate such as benzoic acid, and halogen containing such as trichloroacetic acid. Carboxylates, hydroxycarboxylates such as lactates, inorganic salts such as carbonates, organic sulfonates such as 1-propanesulfonate, organic sulfates such as lauryl sulfate, oxides, hydroxides, chlorides And chelate compounds with alkoxide, acetylacetonate and the like, and are added to the reaction system as powder, aqueous solution, ethylene glycol solution, slurry of ethylene glycol and the like. These metal compounds are added so that the residual amount of the elements of these metal compounds per ton of the produced polymer is in the range of 0.05 to 3.0 mol.
[0034]
Also, various phosphorus compounds can be used as stabilizers. Phosphorus compounds used in the present invention include phosphoric acid compounds, phosphorous acid compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. System compounds. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, and dibutyl phosphate. Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methylphosphonic acid, dimethyl phosphonate methyl, dimethyl ethyl phosphonate, dimethyl phenyl phosphonate, diethyl phenyl phosphonate, phenyl phosphonate Diphenyl ester, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenylphosphinic acid, methyl diphenylphosphinate, phenyldiphenylphosphinate Phenyl phosphinic acid, methyl phenyl phosphinate, phenyl phenyl phosphinate, diphenyl phosphine oxide, methyl diphenyl phosphine oxide, triphenyl phosphine oxide, etc., which may be used alone or in combination of two or more. Is also good. The phosphorus compound is added at any stage of the polyester production reaction step so that the residual amount of phosphorus in the produced polymer is in the range of 5 to 100 ppm.
[0035]
Further, metal compounds other than those described above can also be used as long as they do not affect the properties of the polyester composition of the present invention. Specific examples include oxides, halides, hydroxides, carbonates, carbonates, sulfates, alkoxides and fats such as copper, boron, indium, hafnium, niobium, tantalum, bismuth, chromium, molybdenum, tellurium, nickel and the like. Group or aromatic carboxylate.
[0036]
In the production of the polyester according to the present invention, a basic nitrogen compound can be used. The basic nitrogen compound may be any of aliphatic, alicyclic, aromatic and heterocyclic nitrogen compounds. Specific examples include triethylamine, tributylamine, dimethylaniline, dimethylaniline, pyridine, quinoline, dimethylbenzylamine, piperidine, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, triethylbenzylammonium hydroxide, imidazole, imidazoline and the like. . These compounds may be used in a free form or as a salt of a lower fatty acid or TPA. The addition of these basic nitrogen compounds to the reaction system can be appropriately selected at any stage until the end of the initial polycondensation reaction, and may be used alone or in combination of two or more. Good.
[0037]
The compounding amount of these basic nitrogen compounds is 0.01 to 1 mol%, preferably 0.05 to 0.7 mol%, more preferably 0.1 to 0.5 mol%, based on polyester. If the amount of the basic nitrogen compound is less than 0.01 mol%, the transparency of the hollow molded article made of the obtained polyester, particularly the stretched heat-set hollow molded article, may be extremely poor. If it exceeds 1 mol%, the color tone of the polyester may be deteriorated.
[0038]
The polyester composition of the present invention is a polyester composition comprising a polyester chip whose main repeating unit is ethylene terephthalate, and 0.1 to 5,000 ppm of fine polyester having the same composition as the polyester chip, The crystallization temperature (Tc2 ′) of the polyester fine at the time of cooling measured by DSC (differential scanning calorimetry) is 195 ° C. or lower, and the polyester composition is melted at a temperature of 290 ° C. for 60 minutes. A polyester composition characterized in that the amount of increase of the monomer is 0.50% by weight or less.
[0039]
In the polyester production process, in the step of chipping the melt polymerized polymer, the solid phase polymerization step, the step of transporting the melt polymerized polymer chip or the solid state polymerized polymer chip, etc., the chip originally set at the time of granulation is used. Very small particles or powders are generated. Here, such a fine granular material or powder is referred to as fine, and a thin film having a thickness of about 0.5 mm or less is referred to as a film. In the process of producing polyester, high-purity raw materials and secondary materials are used, and water introduced from outside the system is used for filtration of molten polycondensation polymer, filtration of polyester chip cooling water, ion exchange treatment, and chip water treatment. Filtration and ion exchange treatment, measures such as foreign matter and impurities other than the polyester used are carried out by filtering gas used for transporting chips, etc. It can be free from impurities.
[0040]
Such a fine or film-like material has a property of accelerating crystallization, and when present in a large amount, the transparency of a molded product formed from such a polyester composition, particularly a bottle, becomes extremely poor. Also, the shrinkage amount during crystallization of the bottle plug portion does not fall within the specified value range, and the bottle cannot be sealed with the cap. In particular, fines having a crystallization temperature during cooling (Tc2 ′) exceeding 195 ° C. have a very large crystallization promoting effect, so it is important to exclude such fines.
[0041]
The content of the fines in the polyester composition of the present invention is 0.1 to 5000 ppm, preferably 0.1 to 3000 ppm, more preferably 0.1 to 1000 ppm, still more preferably 0.1 to 500 ppm, and most preferably Preferably it is 0.1-100 ppm. If the fine content is less than 0.1 ppm, the crystallization rate becomes very slow, and the crystallization of the plug portion of the hollow molded article becomes insufficient, and therefore, the shrinkage amount of the plug portion falls within the specified value range. Since it does not fall within the range, a poor capping phenomenon occurs, and a sheet-like material having poor dimensional stability after container molding is given. If it exceeds 5000 ppm, the crystallization speed is increased and the fluctuation of the speed is increased. Therefore, in the case of a sheet-like material, the transparency and the surface state are deteriorated, and when it is stretched, the unevenness in thickness is deteriorated. In addition, the crystallinity of the plug part of the hollow molded body becomes excessively large and fluctuates, so that the amount of shrinkage of the plug part does not fall within the specified value range, and the cap part of the plug part becomes defective and leakage of contents occurs. In addition, the preform for hollow molding becomes white, and normal stretching becomes impossible. In particular, the fine content of the polyester composition for a stretched hollow molded article is preferably 0.1 to 500 ppm, more preferably 100 ppm or less, further preferably 50 ppm or less, particularly preferably 30 ppm or less, and most preferably 20 ppm or less. It is.
[0042]
The fineness of the polyester composition of the present invention has a crystallization temperature (Tc2 ′) of 195 ° C. or lower, preferably 193 ° C. or lower, more preferably 190 ° C., as measured by DSC (differential scanning calorimeter). It must be: When the crystallization temperature (Tc2 ′) of the fines constituting the polyester composition at the time of cooling exceeds 195 ° C., the resulting molded articles such as hollow molded articles have poor transparency, and the fluctuations thereof are large, and the transparency becomes large. A molded article having excellent properties cannot be obtained. Further, since the crystallization speed of the molded body is high, the crystallization speed is increased when the plug portion of the hollow molded body is heated, so that the crystallization of the plug portion may be excessive. As a result, since the shrinkage amount of the plug portion does not fall within the specified value range, capping failure of the plug portion may occur and leakage of contents may occur. In addition, the preform for hollow molding is whitened, which makes normal stretching impossible, and may cause uneven thickness. Further, the obtained sheet-like material has poor transparency and a high crystallization speed, so that normal stretching is impossible, and only a stretched film with large thickness unevenness and poor transparency may be obtained. .
[0043]
The content of the film having the same composition as the polyester in the polyester composition of the present invention is 10 ppm or less, preferably 5 ppm or less, more preferably 1 ppm or less. Since the film-like material is oriented and crystallized, the effect of promoting crystallization is higher than that of fine, and therefore, the limit value of the compounding amount that does not adversely affect is lower. When the compounding amount exceeds 10 ppm, the crystallization rate becomes extremely fast, and the crystallization of the plug portion of the hollow molded container becomes excessive, so that the shrinkage amount of the plug portion does not fall within the specified value range, Poor capping of the plug may result in leakage of the contents or whitening of the preform for hollow molding, which may make normal stretching impossible. The lower limit of the content of the film is desirably 0.1 ppm for economic reasons. Even when the fine crystallization temperature (Tc2 ′) of the film is 195 ° C. or less, the crystallization temperature (Tc2 ′) of the film-like material at the time of cooling is often 195 ° C. or more.
[0044]
Further, in the present invention, the polyester or fine film having the same composition as the polyester chip means that the copolymer component of the fine or film, and the copolymer component content is the same as the polyester chip. It means there is.
[0045]
After the polyester subjected to melt polycondensation is formed into chips, it is transported in a transport pipe to a silo or the like, or is transported to the next step such as a solid phase polymerization step or a water treatment step. At this time, the molten polycondensation chip which maintains a temperature of about 50 to 60 ° C. or higher is transported by a transportation method in which a large shear force or impact force is applied to the chip, or a high-density method using air in the pipe is used. When transported at a high speed, fine or film-like materials having a crystallization temperature (Tc2 ′) at the time of temperature decrease of 195 ° C. or more as described above may be generated.
[0046]
Further, such fines or the like may be further exposed to a high-temperature treatment of about 100 ° C. or more, such as during crystallization treatment or solid-state polymerization treatment, or under a high-temperature condition as described above using a rotary solid-state polymerization apparatus. When the chip is crystallized or subjected to solid-phase polymerization while applying an impact force to the chip, the crystallization temperature (Tc2 ′) when the temperature of the fine or the like is lowered further rises.
[0047]
Therefore, the polyester composition of the present invention can be produced, for example, in the following manner so that impact force and shear force are not applied to the polyester chip as much as possible. In other words, after the melt polycondensation, the molten polyester is extruded into water from a die and cut in water, or after being extruded into the atmosphere, immediately cooled and cooled with cooling water so that the chip temperature exceeds about 50-60 ° C. Chipping while cooling to a temperature that does not occur, and then draining the polyester chips formed into chips, under a condition where the chip temperature does not exceed about 60 ° C., by a vibrating sieve process, a vibrating sieve process, and an airflow classification process using an air flow. Chips having a shape other than a predetermined size, fine or film-like materials are removed, and the chips are sent to a storage tank by a plug transport system or a bucket type conveyor transport system. Chips are withdrawn from the tank by a screw type feeder, transported to the next step by a plug transport system or bucket type conveyor transport system, and provided with an air flow classification process by air flow immediately before the next process. It is preferable to perform a fine or the like removing process.
[0048]
Also, if necessary, if the solid-phase polymerization is to be continued, the above-mentioned molten polycondensed polyester which has been subjected to the fine or film-like material removal treatment is again subjected to an airflow classification step by an air flow immediately before the solid-phase polymerization step. Fine and film-like substances are removed, and the solid-state polymerization step is performed. When transporting melt-polycondensed prepolymer chips to solid-state polymerization equipment or transporting polyester chips after solid-phase polymerization to a sieving process or storage tank, the majority of these transportations are carried out by plug transport or buckets. Adopted a conveyor system, and used a screw feeder to extract chips from the crystallization apparatus or solid-state polymerization reactor. It is preferable to use a device that can be suppressed as much as possible. Immediately before the product is filled in the container, fine or the like is removed by a vibrating sieve process and an airflow classification process using an air flow.
[0049]
Further, when the polyester composition of the present invention is melted at a temperature of 290 ° C. for 60 minutes, the amount of increase of the cyclic trimer needs to be 0.50% by weight or less. The amount of the cyclic trimer increased is preferably 0.40% by weight or less, more preferably 0.30% by weight or less, and further preferably 0.20% by weight or less. When the amount of the cyclic trimer increased by melting at a temperature of 290 ° C. for 60 minutes exceeds 0.50% by weight, the amount of the cyclic trimer increases when the resin for molding is melted, and the oligomer on the surface of the heating mold is increased. Adhesion may increase rapidly, and the transparency of the obtained hollow molded article or the like may be extremely deteriorated. In particular, in the case of a polyester composition containing a fine having a melting peak temperature exceeding 265 ° C., even if the increase of the cyclic trimer is 0.50% by weight or less, the transparency of the obtained molded article is not affected. The quality is greatly deteriorated and the commercial value may be lost.
[0050]
The polyester composition of the present invention, in which the amount of the cyclic trimer increased by melting at a temperature of 290 ° C. for 60 minutes is 0.50% by weight or less, is obtained by melting the polyester obtained after melt polycondensation or solid phase polymerization. It can be produced by deactivating the condensation catalyst.
[0051]
Examples of the method for deactivating the polyester polycondensation catalyst include a method of subjecting a polyester chip to contact treatment with water, steam or a steam-containing gas after melt polycondensation or after solid-phase polymerization. The degree of the increase of the cyclic trimer can be controlled by appropriately changing the contact treatment conditions such as the contact treatment temperature and the contact treatment time.
A method for treating a polyester chip with water, steam or a steam-containing gas to achieve the above object will be described below.
[0052]
Examples of the hot water treatment method include a method of immersing in water and a method of spraying water on a chip with a shower. The treatment time is 5 minutes to 2 days, preferably 10 minutes to 1 day, more preferably 30 minutes to 10 hours, and the water temperature is 20 to 180 ° C, preferably 40 to 150 ° C, more preferably 50 to 150 ° C. 120 ° C.
[0053]
Hereinafter, a method for industrially performing water treatment will be described, but the method is not limited thereto. The treatment method may be either a continuous method or a batch method, but the continuous method is preferable for industrial use.
[0054]
In the case of treating the polyester chips with water in a batch system, a silo-type treatment tank may be used. That is, the chips of polyester are received in a silo in a batch system, and water treatment is performed. When the polyester chips are treated with water in a continuous manner, the polyester chips can be continuously or intermittently received in the tower-type treatment tank from above and subjected to water treatment.
[0055]
Regardless of whether the water treatment method is a continuous method or a batch method, the number of particles having a particle size of 1 to 25 μm existing in water introduced from outside the system is represented by X and sodium content. When the amount is N, the content of magnesium is M, the content of calcium is C, and the content of silicon is S, water treatment is performed by satisfying at least one, and preferably all, of the following (5) to (9). I do.

[0056]
By setting any of the number of particles in the water to be introduced into the water treatment tank, and the content of sodium, magnesium, calcium, and silicon in the above range, metal-containing substances such as oxides and hydroxides called scales are treated. Floating and sedimentation, and also adhere to the processing tank wall and piping wall, which adhere to and penetrate the polyester chip, promote crystallization during molding, and prevent bottles with poor transparency Can be.
[0057]
As a method for reducing the number of particles in the water introduced into the water treatment tank to 50,000 or less per 10 ml, an apparatus for removing particles is installed at at least one place in a process until natural water such as industrial water is supplied to the treatment tank. I do.
[0058]
In addition, in order to reduce sodium, magnesium, calcium, and silicon in the water introduced into the water treatment tank, at least one or more places of sodium, magnesium, calcium, and silicon are required in a process until natural water such as industrial water is supplied to the treatment tank. Install a device to remove the water. These devices include devices similar to those used for the treatment of chip cooling water.
[0059]
When the polyester chips are brought into contact with steam or a steam-containing gas for treatment, steam or a steam-containing gas or a steam-containing air at a temperature of 50 to 150 ° C., preferably 50 to 110 ° C. is preferably used as granular polyethylene terephthalate. The granular polyethylene terephthalate is brought into contact with steam in the amount of 0.5 g or more as steam or present in 1 kg of the steam.
[0060]
The contact between the polyester chips and water vapor is usually performed for 10 minutes to 2 days, preferably for 20 minutes to 10 hours.
[0061]
The method of industrially carrying out the contact treatment between granular polyethylene terephthalate and water vapor or a gas containing water vapor is exemplified below, but the method is not limited thereto. The processing method may be either a continuous method or a batch method.
[0062]
When a polyester chip is subjected to a contact treatment with steam in a batch system, a silo-type treatment device may be used. That is, a polyester chip is received in a silo, and steam or a steam-containing gas is supplied in a batch system to perform a contact treatment.
[0063]
If polyester chips are to be continuously contacted with steam, the granular polyethylene terephthalate should be continuously received in a tower-type treatment device from the top, and steam should be continuously supplied in parallel or countercurrent to contact with steam. Can be.
[0064]
As described above, when treated with water or steam, the granular polyethylene terephthalate is drained by a draining device such as a vibrating sieve or a simmon cutter if necessary, and then transferred to the next drying step by a conveyor.
[0065]
The drying of the polyester chips which have been subjected to the contact treatment with water or steam can be carried out by a commonly used polyester drying treatment. As a method of continuous drying, a hopper-type through-air dryer that supplies polyester chips from the upper portion and allows the drying gas to flow from the lower portion is usually used.
As a dryer for drying by a batch method, drying may be performed under atmospheric pressure while passing a drying gas.
[0066]
As the dry gas, atmospheric air may be used, but dry nitrogen and dehumidified air are preferred from the viewpoint of preventing molecular weight reduction due to hydrolysis or thermal oxidative degradation of polyester, and dry nitrogen is particularly preferred.
[0067]
As another means for deactivating the polycondensation catalyst, a method of inactivating the polymerization catalyst by adding and mixing a phosphorus compound to a melt of the polyester after the melt polycondensation or after the solid phase polymerization is used.
[0068]
In the case of a melt-polymerized polyester, the polyester after the completion of the melt polymerization reaction and a polyester resin containing a phosphorus compound are mixed in a device such as a line mixer capable of mixing in a molten state to deactivate the polycondensation catalyst. Method.
[0069]
As a method of blending a phosphorus compound into a solid-phase polymerized polyester, a method of dry blending a phosphorus compound with a solid-phase polymerized polyester or a method of mixing a polyester master-batch chip blended by melting and kneading a phosphorus compound with a solid-phase polymerized polyester chip are used. After a predetermined amount of the phosphorus compound is blended into the polyester by the above method, the mixture is melted in an extruder or a molding machine to deactivate the polycondensation catalyst.
[0070]
Examples of the phosphorus compound to be used include phosphoric acid, phosphorous acid, phosphonic acid and derivatives thereof. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, and dibutyl phosphate. Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methyl phosphonic acid, methyl dimethyl phosphonate, dimethyl ethyl phosphonate, dimethyl phenyl phosphonate, diethyl phenyl phosphonate, diethyl phenyl -Diphosphonic acid diphenyl ester and the like, which may be used alone or in combination of two or more.
[0071]
Further, the content of the cyclic trimer in the polyester composition of the present invention is preferably 0.70% by weight or less, more preferably 0.50% by weight or less, and further preferably 0.40% by weight or less. When a heat-resistant hollow molded article or the like is molded from the polyester composition of the present invention, heat treatment is performed in a heating mold. However, when the content of the cyclic trimer is 0.70% by weight or more, heating is performed. The adhesion of the oligomer to the mold surface may increase rapidly, and the transparency of the obtained hollow molded article or the like may be extremely deteriorated.
[0072]
Further, the polyester according to the present invention, when the content of sodium, the content of magnesium, the content of silicon, and the content of calcium in the cooling water in the chipping step are N, M, S, and C, respectively, It is preferable that the polyester be a chip formed after melt polycondensation so as to satisfy at least one, preferably all of (1) to (4).
N ≦ 1.0 (ppm) (1)
M ≦ 0.5 (ppm) (2)
S ≦ 2.0 (ppm) (3)
C ≦ 1.0 (ppm) (4)
[0073]
The sodium content (N) in the cooling water is preferably N ≦ 0.5 ppm, and more preferably N ≦ 0.1 ppm.
The magnesium content (M) in the cooling water is preferably M ≦ 0.3 ppm, more preferably M ≦ 0.1 ppm.
Further, the content (S) of silicon in the cooling water is preferably S ≦ 0.5 ppm, and more preferably S ≦ 0.3 ppm.
Further, the calcium content (C) in the cooling water is preferably C ≦ 0.5 ppm, and more preferably C ≦ 0.1 ppm.
[0074]
The lower limits of the sodium content (N), magnesium content (M), silicon content (S) and calcium content (C) in the cooling water are N ≧ 0.001 ppm, M ≧ 0.001 ppm, S ≧ 0.02 ppm and C ≧ 0.001 ppm. In order to reduce the amount to less than the lower limit, enormous capital investment is required, and the operating cost becomes extremely high, which may make economic production difficult.
[0075]
If cooling water outside the above-mentioned conditions is used, these metal-containing compounds adhere to the polyester chip surface, and the crystallization speed of the obtained polyester is extremely fast and its fluctuation is undesirably large. The content of the metal in industrial water fluctuates considerably throughout the year, and the metal content adhering to the polyester fluctuates according to this fluctuation, or at least one of the above (1) to (4) Compared with the case where cooling water satisfying the above conditions is used, the molded article made of polyester obtained by using industrial water as cooling water at the time of chipping has poor transparency and its fluctuation is very large. It is preferable that all of the above (1) to (4) are satisfied.
[0076]
Further, when solid-state polymerization of the melt-polycondensed polyester formed into chips while cooling using cooling water deviating from the above-described conditions, the metal adhered to the chip surface in the chip-forming step and brought into the solid-state polymerization reaction device. The contained substance adheres to the vessel wall of the solid-state polymerization apparatus together with a part of the surface layer of the polyester chip. Will adhere. Then, there is a case where a problem arises that this peels off from time to time and mixes into the polyester chip and becomes a foreign substance in a molded product such as a bottle, thereby lowering the commercial value.
[0077]
Further, when producing a sheet, the above-mentioned scale is clogged in the molten polymer filtration filter at the time of film formation, so that the filter-filtration pressure increases sharply, and the operability and productivity are deteriorated. May also occur.
[0078]
A method for controlling the sodium content, magnesium content, silicon content, and calcium content of the cooling water of the chip within the above ranges will be described below, but the present invention is not limited thereto.
[0079]
In order to reduce the amount of sodium, magnesium, calcium, and silicon in the cooling water, an apparatus for removing sodium, magnesium, calcium, and silicon is installed at at least one or more locations in the chip forming process until industrial water is sent. In addition, a filter is installed in order to remove clay minerals such as silicon dioxide and aluminosilicate which have become particulate. Examples of an apparatus for removing sodium, magnesium, calcium, and silicon include an ion exchange apparatus, an ultrafiltration apparatus, and a reverse osmosis membrane apparatus.
[0080]
Further, it is desirable to use water in which particles having a particle size of 1 to 25 μm existing in the introduced water introduced from outside the system are reduced to 50,000 particles / 10 ml or less. The number of particles having a particle size of 1 to 25 μm in the introduced water is preferably 10,000 particles / 10 ml or less, more preferably 1,000 particles / 10 ml or less, and particularly preferably 100 particles / 10 ml or less.
[0081]
Further, the polyester composition of the present invention is characterized in that at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin and a polyacetal resin is added to the polyester composition at 0.1 ppb to 50,000 ppm. It is a polyester composition. The mixing ratio of the resin to the polyester used in the present invention is from 0.1 ppb to 50,000 ppm, preferably from 0.3 ppb to 10000 ppm, more preferably from 0.5 ppb to 100 ppm, further preferably from 1.0 ppb to 1 ppm, particularly preferably. It is 1.0 ppb to 45 ppb. If the compounding amount is less than 0.1 ppb, the crystallization speed becomes very slow, and the crystallization of the plug portion of the hollow molded article becomes insufficient. The capping is poor because it does not fall within the value range, and the stretch heat-fixing mold for molding the heat-resistant hollow molded article is heavily contaminated, and the mold must be cleaned frequently to obtain a transparent hollow molded article. May have to be done. If the content exceeds 50,000 ppm, the crystallization rate becomes high, and the crystallization of the plug portion of the hollow molded article becomes excessive. As a result, the amount of shrinkage and shrinkage of the plug portion does not fall within the specified value range, resulting in poor capping. In some cases, leakage of an object occurs, or the preform for a hollow molded body is whitened, so that normal stretching cannot be performed. In the case of a sheet-like material, if it exceeds 50,000 ppm, the transparency becomes extremely poor, and the stretchability is deteriorated, so that normal stretching is impossible, and only a stretched film with large unevenness of thickness and poor transparency is obtained. May not be possible.
[0082]
Examples of the polyolefin resin blended in the polyester composition of the present invention include a polyethylene resin, a polypropylene resin, and an α-olefin resin. These resins may be crystalline or amorphous.
[0083]
Examples of the polyethylene resin blended in the polyester composition of the present invention include, for example, ethylene homopolymer, ethylene and propylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, Other α-olefins having about 2 to 20 carbon atoms, such as hexene-1, octene-1, and decene-1, and vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, styrene, Copolymers with a vinyl compound such as a saturated epoxy compound are exemplified. Specifically, for example, ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-butene-1 copolymer such as ultra low / low / medium / high density polyethylene (branched or linear) 4-methylpentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer And an ethylene-based resin such as an ethylene-ethyl acrylate copolymer.
[0084]
Examples of the polypropylene resin blended in the polyester composition of the present invention include, for example, propylene homopolymer, propylene, ethylene, butene-1, 3-methylbutene-1, pentene-1, and 4-methylpentene-1. , Hexene-1, octene-1, decene-1, etc., other α-olefins having about 2 to 20 carbon atoms, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylate, methacrylate, styrene, etc. And a copolymer with a diene such as hexadiene, octadiene, decadiene and dicyclopentadiene. Specific examples include propylene-based resins such as propylene homopolymer (atactic, isotactic, syndiotactic polypropylene), propylene-ethylene copolymer, and propylene-ethylene-butene-1 copolymer.
[0085]
The α-olefin resin blended in the polyester composition of the present invention includes a homopolymer of an α-olefin having about 2 to 8 carbon atoms, such as 4-methylpentene-1, and those α-olefins and ethylene. And copolymers with other α-olefins having about 2 to 20 carbon atoms, such as propylene, butene-1, 3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1. Can be Specifically, for example, butene-1 based resin such as butene-1 homopolymer, 4-methylpentene-1 homopolymer, butene-1-ethylene copolymer, butene-1-propylene copolymer, and the like; -Methylpentene-1 and C ₂ ~ C ₁₈ And a copolymer with an α-olefin.
[0086]
Examples of the polyamide resin blended in the polyester composition of the present invention include lactam polymers such as butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, ω-laurolactam, 6-aminocaproic acid, and 11-aminocaproic acid. Polymers of aminocarboxylic acids such as -aminoundecanoic acid and 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- or 2,4 Aliphatic diamines such as 1,4-trimethylhexamethylenediamine, alicyclic diamines such as 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xylyl A diamine unit such as an aromatic diamine such as a diamine; Polycondensates with dicarboxylic acid units such as aliphatic dicarboxylic acids such as glutaric acid, adipic acid, suberic acid and sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. And copolymers thereof. Specific examples thereof include nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, and nylon 610. 611, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6 / MXD6, nylon MXD6 / MXDI, nylon 6/66, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T, etc. No. These resins may be crystalline or amorphous.
[0087]
Examples of the polyacetal resin blended in the polyester composition of the present invention include, for example, polyacetal homopolymers and copolymers. As the polyacetal homopolymer, the density measured by the measuring method of ASTM-D792 is 1.40 to 1.42 g / cm. ³ Polyacetal having a melt flow ratio (MFR) of 0.5 to 50 g / 10 minutes measured at 190 ° C. under a load of 2160 g according to ASTM D-1238 is preferred.
[0088]
The polyacetal copolymer has a density of 1.38 to 1.43 g / cm measured by the method of ASTM-D792. ³ A polyacetal copolymer having a melt flow ratio (MFR) in the range of 0.4 to 50 g / 10 minutes measured at 190 ° C. under a load of 2160 g according to ASTM D-1238 is preferable. Examples of these copolymer components include ethylene oxide and cyclic ether.
[0089]
The production of a polyester composition containing the polyolefin resin or the like in the present invention is a method of directly adding and melting and kneading a resin such as the polyolefin resin to the polyester so that the content falls within the above range, or In addition to a conventional method such as a method of melt-kneading and adding as a master batch, the resin is produced at the polyester production stage, for example, during melt polycondensation, immediately after melt polycondensation, immediately after pre-crystallization, during solid state polymerization, At any stage such as immediately after solid-state polymerization, or in a process from the end of the production stage to the molding stage, for example, directly added as powders or under the flow conditions of the polyester chips It is also possible to adopt a method of mixing by, for example, bringing into contact with the resin member, or a method of melting and kneading after the contact treatment.
[0090]
Here, as a method of bringing the polyester chip into contact with the resin member under flow conditions, it is preferable that the polyester chip be brought into collision with the member within an air gap in which the resin member exists, and specifically, For example, immediately after the melt polycondensation of polyester, immediately after pre-crystallization, during the production process such as immediately after solid-phase polymerization, or when filling and discharging the transport container in the transport stage of the polyester chip as a product, A part of a pneumatic transport pipe, a gravity transport pipe, a silo, a magnet part of a magnet catcher, or the like at the time of inserting a molding machine in a chip molding stage is made of the resin, or the resin film, sheet, or molded body is formed. Affixing the resin, lining the resin, or placing the resin member such as a rod-shaped or net-shaped body in the transfer path. To include a method of transferring the polyester chips. The contact time of the polyester chip with the member is usually very short, such as about 0.01 second to several minutes. However, a small amount of the resin can be mixed into the polyester.
[0091]
Further, as a gas which comes into contact with the polyester after the melt polycondensation step or the solid phase polymerization step, particles having a particle size of 0.3 to 5 μm are 1,000,000 (pieces / cubic feet) or less, preferably 500,000 pieces (pieces / cubic feet). G), and more preferably 100,000 (pieces / cubic foot) or less of gas introduced from outside the system. Particles having a particle size exceeding 5 μm in the gas are not particularly limited, but are preferably 5 (pieces / cubic) or less, more preferably 1 (pieces / cubic) or less.
[0092]
In the polyester production process, it is filled into containers such as a silo, a hopper of a molding machine, a transport container, etc., from each of a melt polycondensation process, a solid phase polymerization process, etc., through a sieving process, an airflow classification process, etc. However, for transportation and drying of the polyester during these steps, air near the processing equipment is generally taken into the steps by a blower or the like for use. Conventionally, such air is used untreated or only treated by a purifier equipped with a low-performance filter unit such as type 3 specified in JIS B 9908 (1991). It was common to use it.
However, there was a case where a problem occurred that only a molded article having poor transparency could be obtained from the polyester treated in such a step. In particular, when air having the above-mentioned quality is used as the gas that comes into contact with the polyester before and after the contact treatment step with the member made of the resin, fluctuations in the crystallization speed, transparency, and the like of the obtained molded body are large. And there is a high possibility that a problem will occur.
[0093]
Therefore, in the method for producing the polyester composition of the present invention, at least one of the polyesters after melt polycondensation, after solid-phase polymerization, after water treatment or after contact treatment with the member made of the resin, As a gas to be contacted in any one of the transporting step, the sieving step, the storing step, and the container filling step, particles having a particle size of 0.3 to 5 μm having a particle size of 1,000,000 (pieces / cubic feet) or less are out of the system. It is desirable to use more introduced gases.
[0094]
Hereinafter, a method of controlling the number of particles having a particle size of 0.3 to 5 μm in a gas introduced from outside the system to 1,000,000 (pieces / cubic foot) or less will be described, but the present invention is not limited to this. Absent.
As a method of reducing the number of particles having a particle size of 0.3 to 5 μm in the gas introduced from outside the system to 1,000,000 (pieces / cubic foot) or less, a process until the gas introduced from the outside comes into contact with the polyester chip is used. A cleaning device for removing the particles is installed at at least one or more locations. In the case where the gas is air in the vicinity of the processing equipment, during the process until the air introduced from the air intake port by the blower comes into contact with the polyester chip, type 1 or / and / or JIS B 9908 (1991) is defined. It is preferable to install a gas purifier equipped with a type 2 filter unit and reduce the number of particles having a particle size of 0.3 to 5 μm in the air to 1,000,000 (pieces / cubic feet) or less. Further, by installing a gas purifier equipped with a type 3 filter unit specified in JIS B 9908 (1991) in the air intake port, the gas purifier is used together with the gas purifier equipped with the filter unit. It is possible to extend the life of the filter unit.
[0095]
As a material of an ultra-high-performance filter (hereinafter, abbreviated as HEPA filter) unit of type 1 defined in JIS B 9908 (1991) for removing particles in a gas, a filter paper made of glass fiber is exemplified.
Examples of the material of the high-performance filter unit of the type 2 defined in JIS B 9908 (1991) include a filter made of a polypropylene fiber and a filter made of a laminate of a Teflon (R) film and a PET fiber cloth.
Generally, a polypropylene fiber electrostatic filter is used.
[0096]
In addition, as a material of the low-performance filter unit of the type 3 specified in JIS B 9908 (1991), a nonwoven fabric made of PET or polypropylene is exemplified.
[0097]
The intrinsic viscosity of the polyester composition of the present invention is preferably from 0.55 to 1.50 deciliter / gram, more preferably from 0.58 to 1.20 deciliter / gram. When the intrinsic viscosity of the polyester is less than 0.55 deciliter / gram, the molded product obtained by melt-molding the polyester composition of the present invention may not be sufficiently satisfactory in transparency, heat resistance, mechanical properties and the like. If the intrinsic viscosity exceeds 1.50 deciliter / gram, the resin temperature rises during melting by a molding machine or the like, and thermal decomposition becomes severe, and free low-molecular-weight compounds that affect fragrance retention increase. In some cases, problems such as the molded article being colored yellow may occur.
[0098]
The acetaldehyde content of the polyester composition of the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 10 ppm or less, and further preferably 5 ppm or less. When the acetaldehyde content is 50 ppm or more, the contents such as a container molded from the polyester may deteriorate in flavor and odor.
[0099]
The amount of diethylene glycol copolymerized in the polyester according to the present invention is preferably 0.5 to 5.0 mol%, more preferably 1.0 to 4.5 mol% of the glycol component constituting the polyester. Mol%, more preferably 1.5 to 4.0 mol%. If the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability becomes poor, the molecular weight decreases during molding, and the acetaldehyde content and the formaldehyde content increase undesirably. When the content of diethylene glycol is less than 0.5 mol%, the transparency of the obtained molded article may deteriorate.
[0100]
As described above, the content of the cyclic trimer in the polyester composition of the present invention is 0.70% by weight or less, preferably 0.50% by weight or less, and more preferably 0.40% by weight or less. When molding a heat-resistant hollow molded article or the like from the polyester composition of the present invention, heat treatment is performed in a heating mold, but when the content of the cyclic trimer exceeds 0.70% by weight as described above, In some cases, the adhesion of the oligomer to the surface of the heating mold rapidly increases, and the transparency of the obtained hollow molded article or the like may be extremely deteriorated.
[0101]
In the present invention, the shape of the polyester chip may be any of a cylinder type, a square type, a spherical shape or a flat plate shape. The average particle size is usually in the range of 1.5 to 5 mm, preferably 1.6 to 4.5 mm, and more preferably 1.8 to 4.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.5 to 4 mm and the diameter is about 1.5 to 4 mm. In the case of spherical particles, it is practical that the maximum particle diameter is 1.1 to 2.0 times the average particle diameter and the minimum particle diameter is 0.7 times or more the average particle diameter. The practical weight of the chip is in the range of 10 to 30 mg / piece.
[0102]
Further, the polyester composition of the present invention has a haze of 15% or less of a molded plate having a thickness of 5 mm obtained by injection molding the same, and a test piece from a molded product having a thickness of 2 mm obtained by injection molding. It is desirable that the crystallization temperature (hereinafter referred to as “Tc1”) at the time of the temperature rise be in the range of 150 to 172 ° C. The haze of the molded plate is preferably 10% or less, more preferably 8% or less, and the crystallization temperature (Tc1) at the time of raising the temperature is preferably 153 to 170 ° C, more preferably 155 to 168 ° C. It is.
[0103]
If the haze of the molded plate exceeds 15%, the transparency of the obtained hollow molded article is deteriorated, and this is a problem particularly in the case of a stretched hollow molded article. On the other hand, when Tc1 exceeds 172 ° C., the heating crystallization rate becomes extremely slow, and crystallization of the plug portion of the hollow molded article becomes insufficient, which causes a problem of leakage of contents. When Tc1 is lower than 150 ° C., the transparency of the hollow molded article may be reduced, which may cause a problem.
[0104]
The polyester composition of the present invention is a PET bottle obtained by using a raw material such as dimethyl terephthalate or terephthalic acid obtained by purifying a used PET bottle by a chemical recycling method and recovering the used PET bottle at least as a part of a starting material. It can be used as a mixture with flake-like PET or chip-like PET that has been purified and recovered by a recycling method.
[0105]
It is also possible to simultaneously use a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, and the like in the polyester composition of the present invention.
Examples of the saturated fatty acid monoamide include lauric amide, palmitic amide, stearic amide, behenic amide and the like. Examples of unsaturated fatty acid monoamides include oleic acid amide, erucic acid amido ricinoleic acid amide, and the like. Examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid Amides and the like. Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide and hexamethylene bisoleic acid amide. Preferred amide compounds are saturated fatty acid bisamides, unsaturated fatty acid bisamides, and the like. The compounding amount of such an amide compound is 10 ppb to 1 × 10 ⁵ ppm range.
[0106]
Metal salt compounds of aliphatic monocarboxylic acids having 8 to 33 carbon atoms, such as naphthenic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid, melicic acid, and oleic acid It is also possible to simultaneously use lithium salts, sodium salts, potassium salts, magnesium salts, calcium salts, cobalt salts and the like of saturated and unsaturated fatty acids such as linoleic acid and the like. The compounding amount of these compounds is in the range of 10 ppb to 300 ppm.
[0107]
The polyester composition of the present invention can be preferably used as a packaging material such as a hollow molded article, a tray, a biaxially stretched film, a film for covering a metal can, and the like. Further, the polyester composition of the present invention can also be used as one constituent layer of a multilayer molded article, a multilayer film and the like.
[0108]
The polyester composition of the present invention can be used to form films, sheets, containers, and other packaging materials using commonly used melt molding methods. The mechanical strength can be improved by stretching the sheet-like material comprising the polyester composition of the present invention in at least one direction. The stretched film made of the polyester composition of the present invention is a sheet-like product obtained by injection molding or extrusion molding, and is preferably any one of uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching usually used for PET stretching. It is formed using a stretching method. Also, it can be formed into a reclip shape or a tray shape by pressure forming or vacuum forming.
[0109]
In producing a stretched film, the stretching temperature is usually from 80 to 130 ° C. The stretching may be uniaxial or biaxial, but is preferably biaxial in view of practical physical properties of the film. The stretching ratio is usually 1.1 to 10 times, preferably 1.5 to 8 times in the case of uniaxial stretching. In the case of biaxial stretching, it is usually 1.1 to 8 times in both the longitudinal and transverse directions. , Preferably in the range of 1.5 to 5 times. Further, the ratio of the vertical / horizontal magnification is usually 0.5 to 2, preferably 0.7 to 1.3. The obtained stretched film can be further heat-set to improve heat resistance and mechanical strength. The heat setting is usually performed under tension at 120 ° C. to 240 ° C., preferably 150 ° C. to 230 ° C., usually for several seconds to several hours, preferably for several tens seconds to several minutes.
[0110]
In producing the hollow molded article, a blow-form molded from the polyester composition of the present invention is formed by stretch blow molding, and an apparatus conventionally used for PET blow molding can be used. Specifically, for example, a preform is once molded by injection molding or extrusion molding, and after processing the plug portion and the bottom portion, it is reheated, and biaxial stretch blow molding such as hot parison method or cold parison method is performed. The law applies. In this case, the molding temperature, specifically, the temperature of each cylinder and nozzle of the molding machine is usually in the range of 260 to 300 ° C. The stretching temperature is usually 70 to 120 ° C., preferably 90 to 110 ° C., and the stretching ratio is usually 1.5 to 3.5 times in the longitudinal direction and 2 to 5 times in the circumferential direction. The obtained hollow molded body can be used as it is, but in particular, in the case of beverages requiring heat filling, such as fruit juice beverages, oolong tea, etc., in general, heat-setting treatment is further performed in a blow mold to obtain heat resistant It is used with imparting properties. The heat setting is usually performed at 100 to 200 ° C., preferably 120 to 180 ° C., for several seconds to several hours, preferably for several seconds to several minutes, under tension by compressed air or the like.
[0111]
Also, in order to impart heat resistance to the plug portion, the plug portion of the preform obtained by injection molding or extrusion molding is crystallized in a far infrared or near infrared heater installation oven, Alternatively, the plug portion is crystallized with the heater after the bottle is formed.
[0112]
The polyester composition of the present invention includes a known ultraviolet absorber, an antioxidant, an oxygen scavenger, a lubricant added from the outside or a lubricant internally deposited during the reaction, a release agent, a nucleating agent, Various additives such as an agent, an antistatic agent, a dye, and a pigment may be blended.
[0113]
Further, when the polyester composition of the present invention is used for film applications, calcium carbonate, magnesium carbonate, barium carbonate may be used in the polyester composition in order to improve handling properties such as slipperiness, winding property, and blocking resistance. Inorganic particles such as calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate and magnesium phosphate; organic salt particles such as terephthalate such as calcium and calcium oxalate, calcium, barium, zinc, manganese and magnesium; divinylbenzene, styrene and acrylic Inert particles such as cross-linked polymer particles such as homo- or copolymers of vinyl monomers of acid, methacrylic acid, acrylic acid or methacrylic acid can be contained.
The main method of measuring characteristic values in the present invention will be described below.
[0114]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the measuring method of the main characteristic value in this specification is demonstrated below.
[0115]
(1) Intrinsic viscosity (IV) of polyester
It was determined from the solution viscosity at 30 ° C. in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent.
[0116]
(2) Diethylene glycol content of polyester (hereinafter referred to as [DEG content])
It was decomposed by methanol and the amount of DEG was quantified by gas chromatography and expressed as a ratio (mol%) to the total glycol components.
[0117]
(3) Polyester cyclic trimer content (hereinafter referred to as “CT content”)
300 mg of a sample is dissolved in 3 ml of a mixed solution of hexafluoroisopropanol / chloroform (volume ratio = 2/3), and further diluted with 30 ml of chloroform. To this, 15 ml of methanol was added to precipitate a polymer, followed by filtration. The filtrate was evaporated to dryness, the volume was adjusted to 10 ml with dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.
[0118]
(4) Acetaldehyde content of polyester (hereinafter referred to as "AA content")
A sample / distilled water = 1 g / 2 cc in a glass ampoule purged with nitrogen was sealed and subjected to extraction at 160 ° C. for 2 hours. After cooling, acetaldehyde in the extract was measured by high-sensitivity gas chromatography. The concentration was expressed in ppm.
[0119]
(5) Increase in cyclic trimer when polyester is melted (ΔCT amount)
3 g of the dried polyester chip is placed in a glass test tube, and immersed in a 290 ° C. oil bath for 60 minutes in a nitrogen atmosphere to be melted. The amount of increase of the cyclic trimer at the time of melting is obtained by the following equation.
Cyclic trimer increase during melting (% by weight) =
Cyclic trimer content after melting (% by weight)-Cyclic trimer content before melting (% by weight)
[0120]
(6) Measurement of fine content and film content
Approximately 0.5 kg of the resin is sieved with a wire mesh having a nominal size of 5.6 mm according to JIS-Z8801 (A) and a wire mesh having a nominal size of 1.7 mm (diameter 20 cm) (B) in two stages. It was put on the combined sieve and sieved at 1800 rpm for 1 minute with a rocking sieve shaking tow machine SNF-7 manufactured by Teraoka. This operation was repeated to sieve a total of 20 kg of the resin.
On the above sieve (A), apart from a film-like material having a thickness of about 0.5 mm or less, a chip-like material in which two or more chips are fused together or cut into a size larger than a normal shape. Is removed, the remaining film-like material having a thickness of about 0.5 mm or less and the fines sieved under the sieve (B) are separately washed with ion-exchanged water and washed with Iwaki. The solution was collected by filtration through a glass G1 glass filter. These were dried together with the glass filter in a dryer at 100 ° C. for 2 hours, cooled, and weighed. The same operation of washing and drying with ion-exchanged water was repeated again, and it was confirmed that the weight became constant. The weight of the glass filter was subtracted from the weight to determine the fine weight and the weight of the film. Fine content or film content is the fine weight or film weight / total resin weight sieved. The total content is determined from these values.
[0121]
(7) Measurement of crystallization temperature (Tc2 ') at the time of cooling of fine
Measured using a differential scanning calorimeter (DSC) manufactured by Seiko Electronics Co., Ltd., RDC-220. In (6), fines collected from 20 kg of polyester were dried under reduced pressure at 25 ° C. for 3 days, and 10 mg of a sample was used for one measurement. The temperature is raised from room temperature to 290 ° C. at a rate of 20 ° C./min, maintained at 290 ° C. for 3 minutes, and quenched with liquid nitrogen. Next, after the temperature was raised again under the same conditions, the temperature was maintained at 290 ° C. for 3 minutes, the temperature was lowered to 240 ° C. at a rate of 10 ° C./min, and further lowered to room temperature at a rate of 7 ° C./min. The crystallization peak temperature observed at the time of this temperature decrease is determined, and this is defined as the crystallization temperature at the time of the temperature decrease (Tc2 '). The measurement is performed on a maximum of 10 fine samples, and the average value of the crystallization temperatures at the time of cooling (Tc2 ′) is obtained, and this is defined as the crystallization temperature at the time of the fine cooling (Tc2 ′).
[0122]
(8) Crystallization temperature (Tc1) at the time of temperature rise of molded body
Measured by RDC-220, a differential thermal analyzer (DSC) manufactured by Seiko-Electronic Industry Co., Ltd. A 10 mg sample from the center of a 2 mm thick plate of the molded plate of (13) below was used. The temperature was raised at a temperature rising rate of 20 ° C./min, and the apex temperature of the crystallization peak observed in the course of the heating was measured and defined as the crystallization temperature during temperature rise (Tc1).
[0123]
(9) Average density of polyester chip and density of preform plug
The measurement was performed at 30 ° C. with a density gradient tube of calcium nitrate / water mixed solution.
[0124]
(10) Haze (% haze) and haze spots
A sample was cut out from the body (thickness of about 0.4 mm) of the molded article (thickness 5 mm) and the hollow molded article (14) below, and was subjected to a haze meter model NDH2000 manufactured by Nippon Denshoku Co., Ltd. Measurement. Further, the haze of a molded plate (thickness: 5 mm) formed continuously 10 times was measured, and the haze unevenness was determined as follows.
Haze spot = maximum value of haze / minimum value of haze
[0125]
(11) Density increase due to heating of preform plug
The preform plug was heat-treated for 180 seconds with a homemade infrared heater, a sample was taken from the top surface and the density was measured.
[0126]
(12) Forming a stepped plate
In the molding of the stepped molding plate according to the present invention, a polyester chip dried under reduced pressure at 140 ° C. for about 16 hours using a reduced pressure drier is drawn by an M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. 1, 2 mm to 11 mm having a gate portion (G) as shown in FIG. 2 (A portion thickness = 2 mm, B portion thickness = 3 mm, C portion thickness = 4 mm, D portion thickness = 5 mm, E portion (Thickness = 10 mm, thickness of F portion = 11 mm) was injection molded.
[0127]
Dry inert gas (nitrogen gas) purge was performed in the molding material hopper in order to prevent moisture absorption of the chips during molding by using polyester chips which had been dried under reduced pressure using a Yamato Scientific Vacuum Dryer Model DP61. The plasticizing conditions by the M-150C-DM injection molding machine were as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, cylinder temperature 45 ° C, 250 ° C from immediately below the hopper, and nozzles And 290 ° C. The injection conditions were such that the injection speed and the holding pressure were 20%, and the injection pressure and the holding pressure were adjusted so that the weight of the molded product was 146 ± 0.2 g. At that time, the holding pressure was 0.5 MPa lower than the injection pressure. It was adjusted.
The upper limits of the injection time and the dwell time are set to 10 seconds and 7 seconds, respectively, and the cooling time is set to 50 seconds. The total cycle time including the time for removing the molded product is about 75 seconds.
Cooling water having a water temperature of 10 ° C. is constantly introduced into the mold to control the temperature. The mold surface temperature during stable molding is about 22 ° C.
[0128]
The test plate for evaluating the characteristics of the molded article was arbitrarily selected from among the stable molded articles at the 11th to 18th shots from the start of molding after the introduction of the molding material and the replacement of resin.
A plate having a thickness of 2 mm (part A in FIG. 1) is used for measurement of the crystallization temperature (Tc1) when the temperature is raised, and a plate having a thickness of 5 mm (part D in FIG. 1) is used for measuring haze (% haze).
[0129]
(13) Molding of hollow molded body
The polyester was dried with a dryer using dehumidified air, and a preform was molded at a resin temperature of 290 ° C. using an M-150C (DM) injection molding machine manufactured by Koki Seisakusho. The plug portion of this preform was heated and crystallized by a home-made plug portion crystallization apparatus. Next, the preformed body was biaxially stretched and blown at a magnification of about 2.5 times in a longitudinal direction and about 3.8 times in a circumferential direction by an LB-01E molding machine manufactured by CORPOPLAST, and was then set at about 150 ° C. It was heat-set in a mold for about 7 seconds to form a container having a capacity of 2000 cc (body thickness 0.45 mm). The stretching temperature was controlled at 100 ° C.
[0130]
(14) Evaluation of leakage of contents from hollow molded body
The hollow molded body molded in the above (13) was filled with hot water at 90 ° C., capped by a capping machine, the container was turned down and left, and then the leakage of the contents was examined. Also, the deformation of the plug after capping was examined.
[0131]
(15) Sodium content, calcium content, magnesium content and silicon content in the cooling water in the chipping process and the water introduced in the water treatment process
Cooling water or introduced water from which particles have been removed and ion-exchanged is collected and filtered through a 1G1 glass filter manufactured by Iwaki Glass Co., Ltd., and the filtrate is measured by an atomic absorption method, an ICP method, or an IPC-MS method.
[0132]
(16) Measurement of the number of particles in the cooling water of the chipping process, and the water introduced and recycled in the water treatment process
The cooling water in the chipping process, the introduced water after particle removal and ion exchange, or the recycled water treated in the filtration device (5) and the adsorption tower (8) are manufactured by Seishin Enterprise Co., Ltd. The number of particles was measured using a PAC 150, and the number of particles was expressed in units / 10 ml.
[0133]
(17) Measurement of the number of particles in the gas that comes into contact with the polyester chip
The gas sent by a blower or the like for forcibly sending the gas, which has passed through the gas cleaning device, is branched into the main gas stream before being brought into contact with the chip, and introduced into the particle measuring device for measurement. The measurement is repeated five times, the average value is calculated, and the number per cubic foot of gas is calculated.
As a particle measuring device, a light scattering type particle measuring device manufactured by Rion Co., Ltd., KC-01B, was used.
[0134]
(Example 1)
A slurry of high-purity terephthalic acid and ethyl glycol is continuously supplied to a first esterification reactor containing a reactant in advance, and is stirred at about 250 ° C., 0.5 kg / cm. ² The reaction was conducted at G for an average residence time of 3 hours. The reaction was sent to the second esterification reactor and stirred at about 260 ° C., 0.05 kg / cm ² The reaction was carried out to a predetermined degree of reaction. Also, crystalline germanium dioxide is dissolved in water by heating, ethylene glycol is added thereto, and the heat-treated catalyst solution and phosphoric acid ethylene glycol solution are separately and continuously supplied to the second esterification reactor. did. This esterification reaction product is continuously fed to the first polycondensation reactor, and is stirred at about 265 ° C. and 25 torr for 1 hour, and then is stirred at about 265 ° C. and 3 torr for 1 hour in the second polycondensation reactor. The mixture was polycondensed for 1 hour at about 275 ° C. and 0.5-1 torr while stirring in the final polycondensation reactor. The intrinsic viscosity of the melt polycondensation prepolymer was 0.56 dl / g.
[0135]
After cooling the melt polycondensation reaction product with cooling water (sodium content: 0.02 ppm, magnesium content: 0.02 ppm, calcium content: 0.02 ppm, silicon content: 0.08 ppm), chips were formed. The chips having a temperature of 50 ° C. or less were transported to a storage tank, and fines and film-like substances were removed by a vibrating sieving step and an airflow classification step, so that the fine content was reduced to about 50 ppm or less. Next, the mixture is sent to a crystallization apparatus by a bucket type conveyor transport system, continuously crystallized at about 155 ° C. for 3 hours under a nitrogen gas flow, and then charged into a column-type solid-state polymerizer, and then at about 207 ° C. under a nitrogen gas flow. Solid phase polymerization was carried out continuously for about 15 hours to obtain a solid phase polymerized polyester. After the solid phase polymerization, the mixture was continuously treated in a sieving step and a fine removal step to remove fines and film-like substances, and stored in a storage tank.
[0136]
This polyester was treated with water as follows. The apparatus shown in FIG. 3 is used for the water treatment of the polyester chips. The raw material chip supply port (1) at the upper part of the processing tank, the overflow outlet (2) located at the upper limit level of the processing water in the processing tank, An outlet (3) for a mixture of polyester chips and treated water at the lower part of the treatment tank, treated water discharged from the overflow outlet, treated water discharged from the treatment tank, and drainage at the lower part of the treatment tank. A pipe (6) through which treated water discharged from the outlet through the draining device (4) is sent again to the water treatment tank via the fine powder removing device (5) in which the filter medium is a continuous filter made of paper. An inlet (7) for the treated water from which fine powder has been removed, an adsorption tower (8) for adsorbing acetaldehyde in the treated water from which fine powder has been removed, and an inlet (9) having a new ion-exchanged water content of about 50 m. ³ A liter tower-type treatment tank was used.
[0137]
After the fine and film-like substances are removed from the solid-phase polymerized PET chips by a gas stream classification step and a vibrating sieving step, the PET chips are treated in a water treatment tank controlled at a treatment water temperature of 95 ° C. at a rate of 50 kg / hour. Water treatment was carried out by continuously charging from the supply port (1) at the upper part of the tank, and continuously withdrawn as treated PET chips at a rate of 50 kg / hour from the discharge port (3) at the lower part of the processing tank. The content of particles having a particle size of 1 to 25 μm in the introduced water collected before the ion-exchanged water introduction port (9) of the above treatment apparatus is about 1900 particles / 10 ml, the sodium content is 0.02 ppm, and the magnesium content is 0. 02 ppm, calcium content is 0.03 ppm, silicon content is 0.09 ppm, and the number of particles having a particle size of 1 to 40 μm of the recycled water treated in the filtration device (5) and the adsorption tower (8) is about 10,000. Pieces / 10 ml.
[0138]
After the water treatment, fine and the like were removed in the vibration type sieving process and the airflow classification process.
The intrinsic viscosity of the obtained PET composition is 0.74 deciliter / gram, the DEG content is 2.7 mol%, the content of the cyclic trimer is 0.32% by weight, and the increase in the cyclic trimer is 0.1%. 12% by weight, average density is 1.4221 g / cm ³ , AA content was 3.2 ppm, and fine content was about 50 ppm. The crystallization temperature (Tc2 ′) of the fine at the time of cooling was 180 ° C. In addition, the residual amount of Ge measured by atomic absorption analysis was 48 ppm, and the residual amount of P was 31 ppm.
[0139]
The obtained PET composition was evaluated with a molded plate and a biaxially stretched bottle by the methods of (12) and (13) above. Table 1 shows the results.
The haze of the molded plate is 4.1%, the haze unevenness of the molded plate is 0.2%, the Tc1 of the molded plate is 169 ° C., the density of the plug portion is 1.378 g / cm 3, and the density deviation of the plug portion is 0.002 g /. cm3, a value without a problem. Also, there was no problem in the leakage test of the contents, and there was no deformation of the plug portion. The barrel haze of the obtained bottle was as good as 1.0%. The AA content of the bottle was 16.8 ppm, which was a problem-free value. Further, continuous stretch blow molding of 5000 or more pieces was carried out, but no mold contamination was observed, and there was no problem.
[0140]
In the manufacturing process, all of the melt polymerized prepolymer chips, solid state polymerization chips, and water treatment chips are transported by the bucket type conveyor transport system, and all the chips are extracted from the reactor and the storage tank using the screw type feeder. Was.
In addition, a filter unit made of a PET nonwoven fabric of type 3 of JIS B 9908 (1991) is used as air for contacting the melt polycondensation PET chip or the solid-state polymerization PET chip with the chip before filling and storing the chip in a transport container or a storage container. Air filtered with an attached air purifier and an air purifier equipped with a HEPA filter unit having a particle collection rate of 99% or more of JIS B 9908 (1991) type 1 (the number of particles having a particle size of 0.3 to 5 μm is about (500 pieces / cubic feet) were used. The same applies to Example 2, Example 3, and Comparative Example 1.
[0141]
(Example 2)
Instead of an ethylene glycol solution of crystalline germanium dioxide, an ethylene glycol solution of tetraisopropyl titanate and an ethylene glycol solution of crystalline germanium dioxide were used, and these catalyst solutions were separately used in a second esterification reactor. , And then continuously supplying ethylene glycol solution of phosphoric acid into the transport pipe from the second esterification reactor to the first polycondensation reactor in the same manner as in Example 1. Esterification and polycondensation were carried out, and then chips were formed under the same conditions as in Example 1 to obtain a polyethylene terephthalate prepolymer having an IV of 0.55 dl / g.
Next, solid-state polymerization and water treatment were performed in the same manner as in Example 1.
[0142]
The intrinsic viscosity of the obtained PET composition is 0.74 deciliter / gram, the DEG content is 2.7 mol%, the content of the cyclic trimer is 0.32% by weight, and the increase in the cyclic trimer is 0.1%. The content was 26 wt%, the average density was 1.4221 g / cm3, the AA content was 3.2 ppm, the fine content was about 50 ppm, and the crystallization temperature (Tc2 ') at the time of cooling was 179 ° C. The residual Ge amount measured by atomic absorption analysis was 18 ppm, the residual Ti amount was 0.6 ppm, and the residual P amount was 10 ppm.
[0143]
The obtained PET composition was evaluated with a molded plate and a biaxially stretched bottle by the methods of (12) and (13) above. Table 1 shows the results. The haze of the molded plate was 4.0%, the Tc1 of the molded plate was 170 ° C., and the density of the plug portion was 1.377 g / cm 3, which was a value without any problem. Also, there was no problem in the leakage test of the contents, and there was no deformation of the plug portion. The body haze of the obtained bottle was good by 1.0%. The AA content of the bottle was 18.7 ppm, which was a problem-free value. In addition, continuous stretch blow molding of 5,000 or more was carried out, but no mold contamination was observed, and there was no problem.
[0144]
Only the transportation and withdrawal of the molten polycondensation chips in the production process were performed by the same method using the same apparatus as in Example 1. The solid-state polymerization PET chip was transported by a low-density transport method.
[0145]
(Example 3)
Instead of an ethylene glycol solution of crystalline germanium dioxide, an ethylene glycol solution of crystalline germanium dioxide and a water / ethylene glycol solution of basic aluminum acetate are used. These catalyst solution and an ethylene glycol solution of phosphoric acid are used. Are subjected to esterification and polycondensation in the same manner as in Example 1 except that they are separately and continuously supplied to the second esterification reactor, and then chipped under the same conditions as in Example 1 to obtain IV0. A 56 dl / g polyethylene terephthalate prepolymer was obtained. Next, solid-state polymerization and water treatment were performed in the same manner as in Example 1. The fine removal ability was enhanced.
[0146]
The intrinsic viscosity of the obtained PET composition is 0.74 deciliter / gram, the content of DEG is 2.7 mol%, the content of AA is 3.3 ppm, the content of cyclic trimer is 0.33% by weight, The amount of trimer increased was 0.31% by weight, the average density was 1.4022 g / cm3, the fine content was 12 ppm, the crystallization temperature (Tc2 ') at the time of cooling was 177 ° C, and the film was Did not.
[0147]
The obtained PET composition was evaluated with a molded plate and a biaxially stretched bottle by the methods of (12) and (13) above. Table 1 shows the results.
The haze of the formed plate was 3.9%, the haze unevenness of the formed plate was 0.2%, and the Tc1 of the formed plate was 170 ° C. The density of the bottle plug portion was 1.380 g / cm3, the density deviation of the plug portion was 0.002 g / cm3, which was a problem-free value, and the body haze of the bottle was as good as 1.0%. Also, there was no problem in the leakage test of the contents, and there was no deformation of the plug portion. The AA content of the bottle was 18.5 ppm, which was a problem-free value. In addition, continuous stretch blow molding of 5,000 or more was carried out, but no mold contamination was observed, and there was no problem.
[0148]
The transportation of the melt-polymerized prepolymer chip, the solid-phase polymerization chip, and the water treatment chip in the manufacturing process was performed in the same manner as in Example 1.
[0149]
(Example 4)
After sorting and removing different kinds of resin bottles, the used polyethylene terephthalate bottle from which the label and cap have been removed is pulverized, and the recovered flakes obtained by washing with water are depolymerized with ethylene glycol in the presence of a depolymerization catalyst, and then transesterified with methanol. The crude dimethyl terephthalate obtained by the reaction was purified by distillation, and the purified dimethyl terephthalate thus obtained was hydrolyzed to obtain high-purity terephthalic acid.
[0150]
Esterification reaction of the slurry of terephthalic acid and ethylene glycol (virgin product) (ethylene glycol / terephthalic acid molar ratio = 1.6) charged with bis (hydroxyethyl) terephthalate and maintained at 250 ° C. and normal pressure The esterification reaction was carried out for 4 hours while supplying water to the tank and distilling out by-product water out of the system, and 100 kg of the esterification reaction product was transferred to the polycondensation tank.
[0151]
Subsequently, the same ethylene glycol solution of crystalline germanium dioxide and the same ethylene glycol solution as used in Example 1 were supplied to the polycondensation tank, into which the esterification reaction product had been transferred, from a plurality of polycondensation catalyst supply pipes. After adding the glycol solution, the temperature of the system is raised from 250 ° C. to 275 ° C. over 1 hour, and the pressure is raised from normal pressure to 350 Pa in 1 hour. Was subjected to melt polycondensation for a time period at which the intrinsic viscosity of the product became 0.56 dl / g.
[0152]
It is withdrawn in the form of a strand from a withdrawal port provided at the bottom of the polycondensation tank, and is cooled with ion-exchanged water of the same type as used in Example 1 to form chips, so that the chip temperature is reduced to about 50 ° C. or less, and then a vibrating sieving machine is used. By removing fines and films, the fine content was reduced to about 50 ppm or less.
[0153]
Subsequently, the polyester resin chip obtained above was crystallized by a stirring fluidized crystallizer kept at about 160 ° C., and then transferred to a packed column type solid-state polymerization tower, and solidified at 210 ° C. under nitrogen flow. Phase polymerization was carried out, followed by treatment in a sieving step and a fine removing step to remove fines, thereby reducing the fine content to about 50 ppm. The residual amount of Ge was 45 ppm, and the residual amount of P was 25 ppm.
[0154]
Next, water treatment was performed in the same manner as in Example 1.
The obtained PET composition (PET IV is 0.74 deciliter / gram, DEG content is 3.1 mol%, AA content is 4.5 ppm, cyclic trimer content is 0.35 wt%, The fine content was about 50 ppm, no film-like material was contained, and Tc2 'of fine was 183 ° C).
[0155]
The haze of the molded plate was 8.6%, the haze unevenness of the molded plate was 0.3%, and the Tc1 of the molded plate was 158 ° C. The density of the bottle plug was 1.382 g / cm3, the density deviation of the plug was 0.003 g / cm3, which was a satisfactory value, and the haze of the body of the bottle was as good as 1.4%.
Also, there was no problem in the leakage test of the contents, and there was no deformation of the plug portion. The AA content of the bottle was 21.6 ppm, a value that was no problem.
The transportation of the melt-polymerized prepolymer chips and the solid-phase polymerization chips in the manufacturing process was performed in the same manner as in Example 1.
[0156]
(Comparative Example 1)
Except for increasing the amount of crystalline germanium dioxide, the prepolymer melt-polycondensed in the same manner as in Example 1 to form chips while cooling with the same quality of cooling water, to adjust the chip temperature to about 65 ° C., and to remove fines and the like. It was transported to a temporary storage silo by low-density transport without any treatment. Then, the mixture was put into a rotary tumbler, crystallized at 140 ° C. under reduced pressure while rotating, and then subjected to solid-state polymerization at 215 ° C. The transportation to the solid-state polymerization apparatus and the transportation after the solid-state polymerization were all performed by a low-density transportation method.
The obtained PET composition was subjected to water treatment under the same conditions as in Example 1. In all the processes from the melt polycondensation to after the water treatment, the treatment was not performed with a fine or other removing device.
[0157]
Table 1 shows the properties of the obtained PET, the molded plate formed from the PET, and the biaxially stretched bottle. The obtained bottle was poor in transparency, and the deformation of the plug part and the leakage of the contents were examined. However, the leakage of the contents was severe, which was a problem.
[0158]
[Table 1]

[0159]
【The invention's effect】
According to the polyester composition of the present invention, the crystallization control property during melt molding and the long-term continuous moldability are excellent, and the hollow molded article, sheet-like material and stretched film obtained therefrom are transparent. In particular, it has excellent heat resistance and dimensional stability under heat, and particularly the shrinkage rate of the plug portion of the hollow molded article is in an appropriate range, and when used as a liquid container, residual off-tastes and off-odors are hardly generated.
[Brief description of the drawings]
FIG. 1 is a plan view of a stepped plate used in an example.
FIG. 2 is a side view of the stepped plate of FIG. 1;
FIG. 3 is a schematic diagram of a water treatment apparatus used in an example.
[Explanation of symbols]
1 Raw material chip supply port
2 Overflow outlet
3 Outlet for polyester chips and treated water
4 Drainer
5 Fine removal equipment
6 Piping
7 Inlet for recycled water and / or ion exchanged water
8 Adsorption tower
9 Ion exchange water inlet

Claims (7)

A polyester composition comprising a polyester chip whose main repeating unit is ethylene terephthalate, and 0.1 to 5000 ppm of a fine polyester having the same composition as the polyester chip, as measured by DSC (differential scanning calorimetry). The measured crystallization temperature (Tc2 ′) of the polyester fine at the time of cooling is 195 ° C. or less, and the amount of increase in cyclic trimer when the polyester composition is melted at a temperature of 290 ° C. for 60 minutes is 0.50. % By weight or less. The polyester composition according to claim 1, wherein the content of the film-like material having the same composition as the polyester chips is 10 ppm or less. 3. The polyester composition according to claim 1, wherein the content of the cyclic trimer is 0.70% by weight or less. The polyester, when the content of sodium in the cooling water, the content of magnesium, the content of silicon and the content of calcium in the chipping step after melt polycondensation are N, M, S, and C, respectively, the following: The polyester composition according to any one of claims 1 to 3, wherein the polyester composition is a polyester formed into chips using cooling water satisfying at least one of (1) to (4).
N ≦ 1.0 (ppm) (1)
M ≦ 0.5 (ppm) (2)
S ≦ 2.0 (ppm) (3)
C ≦ 1.0 (ppm) (4) A hollow molded article obtained by molding the polyester composition according to any one of claims 1 to 4. A sheet-like product obtained by extruding the polyester composition according to any one of claims 1 to 4. A stretched film obtained by stretching the sheet material according to claim 6 in at least one direction.

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