JP2004002555A - Polyester composition and molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition which has a high rate of crystallization and, simultaneously, can stably perform crystallization treatment. <P>SOLUTION: The polyester composition comprises 100 pts.wt. polyester (A) having an ethylene arylate as the main repeating unit and 0.1-30 pts.wt. m-xylylene group-containing polyamide (B), and the heating-up crystallization temperature of the polyester composition is 135-155°C. <P>COPYRIGHT: (C)2004,JPO

Description

【化２】

【化３】

【化４】

【００４８】
（ただし、Ｒ_１〜Ｒ_７は同一又は異なる基であって、水素、アルキル基、アリール基、シクロアルキル基又はアリールアルキル基、Ｘ_１〜Ｘ_５は同一又は異なる基であって、水素、アルキル基、アリール基、シクロアルキル基、アリールアルキル基又はアルカリ金属であるか、あるいは、各式中のＲ_１〜Ｒ_７とＸ_１〜Ｘ_５のうちそれぞれ１個は互いに連結して環構造を形成してもよい）
【００４９】
化学式（Ｃ−１）で表されるホスフィン酸化合物としては、ジメチルホスフィン酸、フェニルメチルホスフィン酸、次亜リン酸、次亜リン酸ナトリウム、次亜リン酸カリウム、次亜リン酸リチウム、次亜リン酸エチル、
【化５】

【化６】

の化合物及びこれらの加水分解物並びに上記ホスフィン酸化合物の縮合物等がある。
【００５０】
化学式（Ｃ−２）で表される亜ホスホン酸化合物としては、フェニル亜ホスホン酸、フェニル亜ホスホン酸ナトリウム、フェニル亜ホスホン酸カリウム、フェニル亜ホスホン酸リチウム、フェニル亜ホスホン酸エチル等がある。
【００５１】
化学式（Ｃ−３）で表されるホスホン酸化合物としてはフェニルホスホン酸、エチルホスホン酸、フェニルホスホン酸ナトリウム、フェニルホスホン酸カリウム、フェニルホスホン酸リチウム、フェニルホスホン酸ジエチル、エチルホスホン酸ナトリウム、エチルホスホン酸カリウム等がある。
【００５２】
化学式（Ｃ−４）で表される亜リン酸化合物としては、亜リン酸、亜リン酸水素ナトリウム、亜リン酸ナトリウム、亜リン酸トリエチル、亜リン酸トリフェニル、ピロ亜リン酸等がある。
【００５３】
また、下記化学式（Ｄ）で表されるアルカリ化合物を添加すると、本発明のポリエステル組成物の熱安定性がさらに向上することを見出した。
Ｚ−ＯＲ_８　　（Ｄ）
（ただし、Ｚはアルカリ金属、Ｒ_８は水素、アルキル基、アリール基、シクロアルキル基、−Ｃ（Ｏ）ＣＨ_３又は−Ｃ（Ｏ）ＯＺ’（Ｚ’は水素又はアルカリ金属））
【００５４】
化学式（Ｄ）で表されるアルカリ化合物としては、水酸化ナトリウム、ナトリウムメトキシド、ナトリウムエトキシド、ナトリウムプロポキシド、ナトリウムブトキシド、カリウムメトキシド、リチウムメトキシド、酢酸ナトリウム、炭酸ナトリウム及びアルカリ土類金属を含むアルカリ土類化合物等を挙げることができるが、いずれもこれらの化合物に限定されるものではない。
【００５５】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）中の前記アルカリ化合物の含有量は、リン原子含有量（Ｐ）の１．５〜６．０倍が好ましい。より好ましくは１．８〜５．５倍、さらに好ましくは２．０〜５．０倍である。アルカリ化合物の含有量がリン原子含有量（Ｐ）の１．５倍より少ないと、ゲル化が促進されやすくなる。一方、アルカリ化合物の含有量がリン原子含有量（Ｐ）の６．０倍より多いと、重合速度が遅くなり、粘度も十分に上がらず、かつ特に減圧系ではゲル化が促進され不経済である。
【００５６】
本発明で使用する前記化学式（Ｃ−１）〜（Ｃ−４）及び化学式（Ｄ）で表される化合物はそれぞれ単独で用いてもよいが、特に併用して用いる方が、ポリエステル組成物の熱安定性が向上するので好ましい。なお、前述の化合物の他に、従来公知の酸化防止剤、紫外線吸収剤、耐候剤、艶消剤、滑剤、粘度安定剤等を中空成形体の風味保持性、ガスバリア性、透明性を損なわない程度で併用してもよい。
【００５７】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）に前記リン原子含有化合物を配合するには、ポリアミドの重合前の原料、重合中に添加するかあるいは該重合体に溶融混合してもよい。
【００５８】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）の三級窒素の含有量は好ましくは２．０モル％以下、より好ましくは１．５モル％以下、さらに好ましくは１．０モル％以下である。三級窒素の含有量が２．０モル％を超えるメタキシリレン基含有ポリアミド（Ｂ）を含む場合には、成形体がゲル化物による着色した異物状物を含み、また、色も悪くなることがある。特に、延伸成形して得た延伸フィルムや二軸延伸中空成形体では、ゲル状物の存在する個所は正常に延伸されずに肉厚となって、厚み斑の原因となり、商品価値のない成形体が多くなる場合がある。
【００５９】
また、前記メタキシリレン基含有ポリアミド（Ｂ）の３級窒素の含有量の下限は、製造上の理由から０．００１モル％、さらに０．０１モル％、特には０．０５モル％であることが好ましい。３級窒素の含有量が０．００１モル％以下のメタキシリレン基含有ポリアミドを製造しようとする際には、高度に精製した原料を用いる、劣化防止剤を大量に必要とする、重合温度を低く保つ必要がある等の生産性に問題が起こることがある。
【００６０】
なお、ここで言う三級窒素とは、イミノ基に基づく窒素と三級アミドに基づく窒素の両者であり、三級窒素の含有量は、二級アミド（−ＮＨＣＯ−：通常の主鎖を構成するアミド）に基づく窒素に対するモル比（モル％）で表した含有量である。
【００６１】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）の相対粘度は、１．３〜４．０が好ましく、下限はより好ましくは１．６さらに好ましくは１．７、特に好ましくは１．８であり、上限はより好ましくは３．７、さらに好ましくは３．５、特に好ましくは３．０である。相対粘度が１．３以下では分子量が小さ過ぎて、本発明のポリエステル組成物からなる成形体の機械的性質に劣ることがある。逆に相対粘度が４．０以上では、前記ポリアミドの重合に長時間を要し、ポリマーの劣化や好ましくない着色の原因となることがあるだけでなく、生産性が低下しコストアップ要因となる場合がある。
【００６２】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）のチップの形状は、シリンダー型、角型、球状又は扁平な板状等のいずれでもよい。その平均粒径は通常１．０〜５．０ｍｍ、好ましくは１．２〜４．５ｍｍ、さらに好ましくは１．５〜４．０ｍｍの範囲である。例えば、シリンダー型の場合は、長さは１．０〜４．０ｍｍ、径は１．０〜４．０ｍｍ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。
【００６３】
本発明に用いるメタキシリレン基含有ポリアミド（Ｂ）の密度は、１．２０〜１．２４ｍｇ／ｃｍ^３が好ましく、より好ましくは１．２０ｍｇ／ｃｍ^３以上であり、１．２３ｍｇ／ｃｍ^３以下である。
【００６４】
本発明のポリエステル組成物を構成するポリエステル（Ａ）とメタキシリレン基含有ポリアミド（Ｂ）との混合割合は、前記ポリエステル（Ａ）１００重量部に対して前記メタキシリレン基含有ポリアミド（Ｂ）０．１重量部〜３０重量部であることが好ましい。メタキシリレン基含有ポリアミドの（Ｂ）の混合量が、ポリエステル（Ａ）１００重量部に対して０．１重量部未満の場合、結晶化促進効果が不十分である場合がある。また、得られる中空容器の材質中のアセトアルデヒド含有量を２０ｐｐｍ以下に低減することが困難で、充填物の風味や臭いに影響を及ぼす場合がある。メタキシリレン基含有ポリアミド（Ｂ）の混合量がポリエステル（Ａ）１００重量部に対して３０重量部を超える場合は、結晶化促進効果が大き過ぎ、得られた成形体の透明性が非常に悪くなる場合がある。
【００６５】
本発明のポリエステル組成物の昇温結晶化温度（以下、Ｔｃ１と略称することがある）は示差走査熱量計にて測定した値で１３５〜１５５℃の範囲であることが必要である。測定するポリエステル組成物は、ポリエステル（Ａ）とメタキシリレン基含有ポリアミド（Ｂ）が溶融混合されたブレンド体である場合にはそのもの、ポリエステル（Ａ）とメタキシリレン基含有ポリアミド（Ｂ）とがそれぞれチップで混合されたドライブレンド体である場合には、２９０℃の成形温度で射出成形して得たブレンド体、である。
【００６６】
本発明のポリエステル組成物のＴｃ１が１３５℃未満の場合は、結晶化による白化が生じやすく成形体に十分な耐熱性を付与するための加熱ができず耐熱性が不十分となったり、白化して透明性を損なうことになる。特に、中空成形体に用いる場合は、プリフォームの胴部をブロー成形のために加熱する際に、結晶化による白化が生じやすく十分な耐熱性を付与するためのプリフォーム温度まで加熱できず耐熱性が不十分となったり、肩部や胴部が白化して透明性を損なうことがある。
【００６７】
一方、本発明のポリエステル組成物のＴｃ１が１５５℃を超える場合は、目的の結晶化度まで加熱結晶化するために長時間加熱が必要となり生産性が低下する傾向にある。特に、成形体が中空成形体である場合は、口栓部を目的の結晶化度まで加熱結晶化するために長時間加熱が必要となり生産性が低下する傾向にある。
【００６８】
また、本発明のポリエステル組成物中のアセトアルデヒド含有量は、好ましくは２０ｐｐｍ以下、より好ましくは１５ｐｐｍ以下、さらに好ましくは１０ｐｐｍ以下である。本発明のポリエステル組成物中のアセトアルデヒド含有量が２０ｐｐｍを超えている場合には、成形体、例えば、中空成形体、シート状物、延伸フィルム等に充填された飲料や接触した食品の風味や臭いに影響を及ぼすことがあり好ましくない。
【００６９】
また、本発明のポリエステル組成物中の環状エステル３量体含有量は、好ましくは０．５０重量％以下、より好ましくは０．４５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中の環状エステル３量体含有量が０．５０重量％を超えている場合には、加熱処理条件によっては加熱金型表面へのオリゴマー付着が急激に増加して、成形体の透明性が非常に悪いことがあり、特に、耐熱性の中空成形体等の場合には大きい影響を受けることがある。
【００７０】
本発明のポリエステル組成物中のアジピン酸、メタキシリレンジアミン及びアジピン酸とメタキシリレンジアミンからなる環状体から選ばれる１種以上のモノマー類、あるいは、環状体の遊離した状態での含有量は合計量で０．３０重量％以下であることが好ましい。より好ましくは、０．２５重量％以下であり、さらに好ましくは０．２０重量％以下である。本発明のポリエステル組成物から成形体、特に、耐熱性の中空成形体等を成形する場合、上記モノマー類、あるいは環状体の含有量が０．３０重量％を超える場合には、加熱金型表面へのモノマー類、あるいは環状体の付着が急激に増加し、中空成形体等の透明性が非常に悪化することがある。さらに、中空成形体等に充填された飲料の風味や臭いに影響を及ぼす場合がある。
【００７１】
なお、前記のアジピン酸とメタキシリレンジアミンからなる環状体とは、下記化学式で表されるアジピン酸とメタキシリレンジアミンの縮合物である。
【化７】

【００７２】
また、本発明のポリエステル組成物を２９０℃の温度で６０分間溶融したときの環状エステル３量体増加量は０．５０重量％以下であることが望ましい。環状エステル３量体増加量は好ましくは０．３０重量％以下、より好ましくは０．２０重量％以下であることが望ましい。２９０℃の温度で６０分間溶融したときの環状エステル３量体増加量が０．５０重量％を越えるポリエステル組成物は、ポリエステル組成物を成形する際の樹脂溶融時に環状エステル３量体が増加し、加熱処理条件によっては加熱金型表面へのオリゴマー付着が急激に増加し、中空成形体等の透明性が非常に悪化することがある。
【００７３】
２９０℃の温度で６０分間溶融したときの環状エステル３量体増加量が０．５０重量％以下である本発明のポリエステル組成物を得るのに用いるポリエステル（Ａ）は、溶融重縮合後や固相重合後に得られたポリエステルに残存する重縮合触媒を失活処理したポリエステルを用いて製造することができる。ポリエステル中の重縮合触媒を失活処理する方法としては、溶融重縮合後や固相重合後にポリエステルチップを水や水蒸気又は水蒸気含有気体と接触処理する方法を挙げることができる。
【００７４】
前記の目的を達成するためにポリエステルチップを水や水蒸気、例えば水蒸気単独、水蒸気含有ガス又は水蒸気含有空気、と接触処理する方法を次に述べる。
【００７５】
ポリエステルチップの水処理方法としては、水中に浸ける方法やシャワーでチップ上に水をかける方法等を挙げることができる。処理時間としては５分〜２日間、好ましくは１０分〜１日間、さらに好ましくは３０分〜１０時間で、水の温度としては２０〜１８０℃、好ましくは４０〜１５０℃、さらに好ましくは５０〜１２０℃である。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が、工業的に行うためには連続方式の方が好ましい。
【００７６】
ポリエステルチップをバッチ方式で水処理する場合は、サイロタイプの処理槽を挙げることができる。ポリエステルチップを連続方式で水処理する場合は、塔型の処理槽に継続的又は間欠的にポリエステルチップを上部より受け入れ、水処理することができる。
【００７７】
また、ポリエステルチップと水蒸気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、例えば水蒸気単独、水蒸気含有ガス又は水蒸気含有空気、を好ましくは粒状ポリエチレンテレフタレート１ｋｇ当り、水蒸気として０．５ｇ以上の量で供給するか、または、存在させて粒状ポリエチレンテレフタレートと水蒸気とを接触させる。
【００７８】
この、ポリエステル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時間行う。
【００７９】
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。
【００８０】
ポリエステル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を挙げることができる。すなわち、ポリエステルチップをサイロへ受け入れ、バッチ方式で、水蒸気単独、水蒸気含有ガス又は水蒸気含有空気を供給し接触処理を行う。
【００８１】
ポリエステル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ー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。
【００８２】
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ートを必要に応じて振動篩機、シモンカーター等の水切り装置で水切りし、コンベヤーによって次の乾燥工程へ移送する。
【００８３】
水又は水蒸気と接触処理したポリエステルチップの乾燥は、通常用いるポリエステルの乾燥処理方法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チップを供給し、下部より乾燥ガスを通気するホッパー型の通気乾燥機が通常使用される。
【００８４】
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。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、除湿空気が好ましい。
【００８５】
また、本発明に用いるポリエステル（Ａ）は、ポリオレフィン樹脂、ポリアミド樹脂、ポリアセタール樹脂、ポリブチレンテレフタレート樹脂からなる群から選ばれた少なくとも１種の樹脂を０．１ｐｐｂ〜１０００ｐｐｍ配合したポリエステルであることができる。この場合、本発明に用いるポリエステル（Ａ）中での前記のポリオレフィン樹脂等の配合割合は、通常０．１ｐｐｂ〜１０００ｐｐｍ、好ましくは０．３ｐｐｂ〜１００ｐｐｍ、より好ましくは０．５ｐｐｂ〜１ｐｐｍ、さらに好ましくは０．５ｐｐｂ〜４５ｐｐｂである。
【００８６】
ポリエステル（Ａ）でのポリオレフィン樹脂等の配合量が０．１ｐｐｂ未満の場合は、結晶化速度が遅くなる傾向があり、中空成形体の口栓部の結晶化が十分でなくなる傾向にあるため、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収まらずにキャッピング不良となることがあったり、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ことがある。また、１０００ｐｐｍ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進むことがあり、このため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ことがある。また、シート状物の場合、１０００ｐｐｍを越えると透明性が非常に悪くなり、また、延伸性も悪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ィルムしか得られないことがある。
【００８７】
本発明に用いるポリエステル（Ａ）に配合することができ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、又はα−オレフィン系樹脂を挙げることができる。
【００８８】
本発明に用いるポリエステル（Ａ）に配合することができ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、スチレン等のビニル化合物との共重合体等を挙げることができる。具体的には、例えば、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を挙げることができる。
【００８９】
また、本発明に用いるポリエステル（Ａ）に配合することができ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等を挙げることができる。具体的には、例えば、プロピレン単独重合体、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を挙げることができる。
【００９０】
また、本発明に用いるポリエステル（Ａ）に配合することができる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を挙げることができる。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Ｃ２〜Ｃ１８のα−オレフィンとの共重合体等を挙げることができる。
【００９１】
また、本発明に用いるポリエステル（Ａ）に配合することができ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６／６６、ナイロン６／６１０、ナイロン６／１２、ナイロン６／６Ｔ、ナイロン６Ｉ／６Ｔ等を挙げることができる。
【００９２】
また、本発明に用いるポリエステル（Ａ）に配合することができるポリアセタール樹脂としては、例えばポリアセタール単独重合体や共重合体を挙げることができる。ポリアセター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で測定したメルトインデックス（ＭＩ）が０．５〜５０ｇ／１０分の範囲のポリアセタール単独重合体が好ましい。
【００９３】
また、ポリアセター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で測定したメルトインデックス（ＭＩ）が０．４〜５０ｇ／１０分の範囲のポリアセタール共重合体が好ましい。ポリアセタールの共重合成分としては、エチレンオキサイドや環状エーテル等を挙げることができる。
【００９４】
また、本発明に用いるポリエステル（Ａ）に配合することができるポリブチレンテレフタレート樹脂としては、例えばテレフタル酸と１，４−ブタンジオールからなるポリブチレンテレフタレート単独重合体やこれにナフタレンジカルボン酸、ジエチレングリコール、１，４−シクロヘキサンジメタノール等を共重合した共重合体を挙げることができる。
【００９５】
また、本発明に用いることができる、前記のポリオレフィン樹脂、ポリアミド樹脂、ポリアセタール樹脂又はポリブチレンテレフタレート樹脂を配合したポリエステル（Ａ）は、前記ポリエステル（Ａ）に前記の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、マスター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り得ることができるほか、前記のポリオレフィン樹脂等の樹脂を、前記ポリエステル（Ａ）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間に粉粒体として直接に添加するか、あるいは、ポリエステルチップの流動条件下に前記のポリオレフィン樹脂等の樹脂製の部材に接触させる等の方法で混入させた後、溶融混練する方法等により得ることもできる。
【００９６】
ここで、ポリエステルチップを流動条件下に前記のポリオレフィン樹脂等の樹脂製の部材に接触させる方法としては、前記のポリオレフィン樹脂等の樹脂製の部材が存在する空間内で、ポリエステルチップを該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ーのマグネット部等の一部を前記のポリオレフィン樹脂等の樹脂製とするか、または、前記のポリオレフィン樹脂等の樹脂をライニングするか、あるいは前記移送経路内に棒状又は網状体等の前記のポリオレフィン樹脂等の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を挙げることができる。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（Ａ）に前記のポリオレフィン樹脂等の樹脂を微量混入させることができる。
【００９７】
また、本発明に用いるポリエステル（Ａ）のアセトアルデヒド含有量は１０ｐｐｍ以下、好ましくは８ｐｐｍ以下、より好ましくは６ｐｐｍ以下、さらに好ましくは４ｐｐｍ以下、ホルムアルデヒド含有量は６ｐｐｍ以下、好ましくは５ｐｐｍ以下、より好ましくは４ｐｐｍ以下であることが望ましい。アセトアルデヒド含有量が１０ｐｐｍを超え及びホルムアルデヒド含有量が６ｐｐｍを超える場合は、成形体等の内容物の風味保持性の効果が低くなる傾向にある。なお、アセトアルデヒド含有量、ホルムアルデヒド含有量の下限はいずれも０．１ｐｐｂであることが好ましい。
【００９８】
また、本発明に用いるポリエステル（Ａ）中に共重合されたジエチレングリコール量は前記ポリエステル（Ａ）を構成するグリコール成分の下限は好ましくは１．０モル％、より好ましくは１．３モル％、さらに好ましくは１．５モル％であり、上限は好ましくは５．０モル％、より好ましくは４．５モル％、さらに好ましくは４．０モル％である。ジエチレングリコール量が５．０モル％を越える場合は、熱安定性が悪くなる傾向にあり、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ることがあり好ましくない。また、ジエチレングリコール含有量が１．０モル％未満の場合は、成形体の透明性が悪くなることがある。
【００９９】
本発明のポリエステル組成物は、従来公知の方法により前記のポリエステル（Ａ）と前記のメタキシリレン基含有ポリアミド（Ｂ）を混合して得ることができる。例えば、前記のポリアミドチップと前記のポリエステルチップとをタンブラー、Ｖ型ブレンダー、ヘンシェルミキサー等でドライブレンドしたもの、さらにドライブレンドした混合物を一軸押出機、二軸押出機、ニーダー等で１回以上溶融混合したもの、さらに必要に応じて溶融混合物を高真空下又は不活性ガス雰囲気下で固相重合したもの等を挙げることができる。
【０１００】
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添加することも可能である。
【０１０１】
ポリエステル組成物に併用添加することができ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、ベヘン酸アミド等を挙げることができる。また、併用添加することができ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、リシノール酸アミド等を挙げることができる。また、併用添加することができ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を挙げることができる。また、併用添加することができる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を挙げることができる。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の範囲であることが好ましい。
【０１０２】
また、ポリエステル組成物に炭素数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、リノール酸等の飽和及び不飽和脂肪酸のリチウム塩、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添加することも可能である。これらの化合物の配合量は、１０ｐｐｂ〜３００ｐｐｍの範囲であることが好ましい。
【０１０３】
本発明のポリエステル組成物には、必要に応じて他の添加剤、例えば、公知の紫外線吸収剤、酸化防止剤、酸素吸収剤、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、顔料等の各種の添加剤を配合してもよい。また、紫外線遮断性樹脂、耐熱性樹脂、使用済みポリエチレンテレフタレートボトルからの回収品等を適当な割合で混合することも可能である。
【０１０４】
また、本発明のポリエステル組成物をシート状物、特に、フィルム用途に使用する場合には、滑り性、巻き性、耐ブロッキング性等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、アクリル酸又はメタクリル酸のビニル系モノマーの単独又は共重合体等の架橋高分子粒子等の不活性粒子を含有させることができる。
【０１０５】
本発明のポリエステル組成物は、一般的に用いる溶融成形法を用いてフィルム、シート、容器、その他の包装材料等の成形体を成形することができる。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、通常のポリエチレンテレフタレート（以下、ＰＥＴと略称することがある）の延伸に用いる一軸延伸、逐次二軸延伸、同時二軸延伸等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。
【０１０６】
延伸フィルムを製造するにあたっては、延伸温度は通常は８０〜１３０℃で行う。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及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。
【０１０７】
中空成形体を製造するにあたっては、成形したプリフォームを延伸ブロー成形して製造することができ、従来ポリエステル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、射出成形又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等の二軸延伸ブロー成形法を適用して成形することができる。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及びノズルの温度は通常２６０〜２９０℃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、ウーロン茶等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、圧空等による緊張下、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。
【０１０８】
また、口栓部に耐熱性を付与するために、射出成形又は押出成形により得られたプリフォームの口栓部を遠赤外線や近赤外線ヒータ設置オー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ータで結晶化させる。
【０１０９】
また、本発明のポリエステル組成物は、積層成形体や積層フィルム等の一構成層としても用いることができる。特に、ＰＥＴとの積層体の形で容器等の製造に使用される。積層成形体の例としては、本発明のポリエステル組成物からなる外層とＰＥＴ内層との二層から構成される二層構造あるいは本発明のポリエステル組成物からなる内層とＰＥＴ外層との二層から構成される二層構造の成形体、本発明のポリエステル組成物を含む中間層とＰＥＴの外層及び最内層から構成される三層構造あるいは本発明のポリエステル組成物を含む外層及び最内層とＰＥＴの中間層から構成される三層構造の成形体、本発明のポリエステル組成物を含む中間層とＰＥＴの最内層、中心層及び最外層から構成される五層構造の成形体等を挙げることができる。ＰＥＴ層には、他のガスバリア性樹脂、紫外線遮断性樹脂、耐熱性樹脂、使用済みポリエチレンテレフタレートボトルからの回収品等を適当な割合で混合使用することができる。
【０１１０】
また、その他の積層成形体の例としては、ポリオレフィン等のポリエステル以外の樹脂との積層成形体、紙や金属板等の異種の基材との積層成形体を挙げることができる。
【０１１１】
前記の積層成形体の厚み及び各層の厚みには特に制限は無い。また、前記の積層成形体は、シート状物、フィルム状物、板状物、中空体、容器等、種々の形状で使用可能である。
【０１１２】
前記の積層成形体の製造は、樹脂層の種類に対応した数の押出機と多層多種ダイスを使用して共押出しにより行うこともできるし、また、樹脂層の種類に対応した数の射出機と共射出ランナー及び射出型を使用して共射出により行うこともできる。
【０１１３】
本発明のポリエステル組成物は、中空成形体、トレイ、二軸延伸フィルム等の包装材、金属缶被覆用フィルム等として好ましく用いることができる。
【０１１４】
また、本発明の組成物は、電子レンジ及び／又はオーブンレンジ等で食品を調理したり、あるいは冷凍食品を加熱するためのトレイ状容器の用途にも用いることができる。この場合は、ポリエステル組成物からのシート状物をトレイ形状に成形後、熱結晶化させて耐熱性を向上させる。
【０１１５】
【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れるものではない。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。
【０１１６】
（評価方法）
（１）ポリエステルの極限粘度（以下、「ＩＶ」という）
１，１，２，２−テトラクロルエタン／フェノール（２：３重量比）混合溶媒中３０℃での溶液粘度から求めた。
【０１１７】
（２）ポリエステル中に共重合されたジエチレングリコール含有量（以下、［ＤＥＧ含有量」という）
メタノールにより分解し、ガスクロマトグラフィーによりＤＥＧ量を定量し、全グリコール成分に対する割合（モル％）で表した。
【０１１８】
（３）環状エステル３量体含有量（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ール／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。これにメタノール１５ｍＬを加えてポリマーを沈殿させた後、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エステル３量体を定量した。
【０１１９】
（４）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／２ｍＬを窒素置換したガラスアンプルに入れ、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ーで測定し、濃度をｐｐｍで表示した。
【０１２０】
（５）溶融時の環状エステル３量体増加量（以下、「△ＣＴ量」という）
乾燥した試料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。溶融時の環状エステル３量体増加量は、次式により求めた。
溶融時の△ＣＴ量（重量％）＝（溶融後のＣＴ量（重量％）−溶融前のＣＴ量（重量％））
【０１２１】
（６）段付き成形板の成形
除湿乾燥したポリエステル組成物を名機製作所社製射出成形機（Ｍ−１５０Ｃ（ＤＭ））により、シリンダー温度２９０℃において、１０℃に冷却した段付き平板金型を用い成形する。得られた段付き成形板は２、３、４、５、６、７、８、９、１０、１１ｍｍの厚みの約３ｃｍ×約５ｃｍ角のプレートを階段状に備えたもので、段付き成形板１個の重量は約１４６ｇである。２ｍｍ厚みのプレート部分は昇温結晶化温度（Ｔｃ１）の測定に使用した。
【０１２２】
（７）昇温結晶化温度
セイコー電子工業社製の示差走査熱分析装置（ＤＳＣ）（ＲＤＣ−２２０）により、昇温速度２０℃／分で測定した。室温から昇温している途中で観察される結晶化ピークのトップ温度を昇温結晶化温度（Ｔｃ１）とした。測定するポリエステル組成物は１０ｍｇで、ポリエステル（Ａ）とメタキシリレン基含有ポリアミド（Ｂ）とが溶融混合されている場合はこのブレンド体を、また、ポリエステル（Ａ）とメタキシリレン基含有ポリアミド（Ｂ）のそれぞれのチップが混合されたドライブレンド体である場合は上記（６）で成形し、得た成形板の２ｍｍ厚みのプレートの中央部のブレンド体を用いた。
【０１２３】
（８）口栓部密度
窒素ガスを用いた乾燥機で乾燥したポリエステルチップの所定量及び窒素ガスを用いた乾燥機で乾燥したメタキシリレン基含有ポリアミドチップの所定量を用いて、名機製作所社製射出成型機（Ｍ−１５０Ｃ（ＤＭ））により樹脂温度２９０℃でプリフォームを成形した。近赤外石英ヒータでプリフォームの口栓部近傍の温度が１８０℃になるように調整し、口栓部結晶化装置にて、プリフォームを回転させながら９０秒間加熱した後、口栓部天面ネジ山開始位置の密度を測定した。密度は純水に硝酸カルシウムを溶解させた密度勾配管（密度範囲１．２８〜１．４２ｇ／ｃｍ^３）を作成し、３０℃の温度で投入後２時間の値で測定した。
【０１２４】
（９）金型汚れの評価
窒素ガスを用いた乾燥機で乾燥したポリエステルチップの所定量及び窒素ガスを用いた乾燥機で乾燥したメタキシリレン基含有ポリアミドチップの所定量を用いて、名機製作所社製射出成型機（Ｍ−１５０Ｃ（ＤＭ））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東洋紡績社製の口栓部結晶化装置で加熱結晶化させた後、コーポプラスト社製延伸ブロー成型機（ＬＢ−０１Ｅ）を用いて二軸延伸ブロー成形し、引き続き約１５５℃に設定した金型内で約１０秒間熱固定し、容積１０００ｍＬの中空成形体を得た。同様の条件で連続的に延伸ブロー成形し、目視で判断して成形体の透明性が損なわれるまでの成形回数で金型汚れを評価した。
【０１２５】
（１０）中空成形体の透明性
上記（９）で３０００本成形後に得られた中空成形体の外観を目視で観察し、下記のように評価した。
○　：　透明であり、未溶融物は見られない
×　：　透明性に劣る、又は未溶融物が見られる
【０１２６】
（１１）官能試験
上記の中空成形体に沸騰した蒸留水を入れ密栓後３０分保持した後、室温に冷却し、室温で１ヶ月間放置し、開栓後風味、臭い等の試験を行った。比較用のブランクとして、蒸留水を使用した。官能試験は１０人のパネラーにより次の基準により実施し、平均値で比較した。
（評価基準）
０：異味、臭いを感じない
１：ブランクとの差をわずかに感じる
２：ブランクとの差を感じる
３：ブランクとのかなりの差を感じる
４：ブランクとの非常に大きな差を感じる
【０１２７】
（実施例及び比較例に使用したポリエチレンテレフタレート（ＰＥＴ））
試験に用いたＰＥＴ（ゲルマニウム残存量＝約４０〜５０ｐｐｍ、リン残存量＝約３０〜３５ｐｐｍ）の特性を表１に示す。これらは、いずれも、連続溶融重縮合−固相重合装置で重合したものである。
・ＰＥＴ（ａ）：固相重合後イオン交換水中で約９０℃で３時間、熱水処理したもの。
・ＰＥＴ（ｂ）：固相重合後熱水処理しなかったもの。
また、ＰＥＴ（ａ）、ＰＥＴ（ｂ）のＤＥＧ含有量は、いずれも、約２．７モル％であった。
【０１２８】
【表１】

【０１２９】
（実施例及び比較例に使用したメタキシリレン基含有ポリアミド（ＭＸＤ６））試験には東洋紡績社製ＭＸＤ６（Ｔ−６００（相対粘度ＲＶ＝２．１））を用いた。
【０１３０】
【表２】

【０１３１】
（実施例１）
ＰＥＴ（ａ）１００．０重量部に対してＭＸＤ６を０．５重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３２】
（実施例２）
ＰＥＴ（ａ）１００．０重量部に対してＭＸＤ６を３．０重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３３】
（実施例３）
ＰＥＴ（ａ）１００．０重量部に対してＭＸＤ６を５．０重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３４】
（実施例４）
ＰＥＴ（ａ）１００．０重量部に対してＭＸＤ６を２０．０重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３５】
（比較例１）
ＰＥＴ（ａ）１００．０重量部に対してＭＸＤ６を０．０１重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３６】
（比較例２）
ＰＥＴ（ｂ）１００．０重量部に対してＭＸＤ６を３．０重量部用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３７】
（比較例３）
ＰＥＴ（ａ）のみを用いて、評価方法（５）の方法により溶融して、△ＣＴ量を測定し、また、評価方法（６）の方法により段付き成形板を成形し、その成形板（２ｍｍ厚プレート部分）のＴｃ１を測定した。また、評価方法（８）の方法によりプリフォームを成形し、そのプリフォームの口栓部を結晶化処理することにより、口栓部密度を測定した。また、評価方法（９）の方法により中空成形体を成形し、その中空成形体の透明性、ＣＴ含有量、ＡＡ含有量を測定した。なお、透明性は中空成形体の胴部を、ＣＴ含有量、ＡＡ含有量は口栓部を測定した。また、金型汚れ評価、官能試験評価も行った。得られた成形体の評価結果を表２に示す。
【０１３８】
【発明の効果】
本発明のポリエステル組成物によれば、結晶化速度が速く、かつ、結晶化処理を安定して行うことができ、また、かかるポリエステル組成物から得られた成形体によれば、風味保持性に優れている。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention has a high crystallization rate used as a material for a sheet-shaped material such as a polyester composition and a molded product, in particular, a material for a hollow molded container such as a bottle for a beverage or a film, a sheet, etc., The present invention also relates to a polyester composition capable of stably performing a crystallization treatment, and a molded article comprising the polyester composition and having excellent flavor retention.
[0002]
[Prior art]
Heat-resistant bottles for content liquids that require hot filling, such as fruit juice drinks, are required to have heat resistance, so the bottle body is heat-fixed by blow molding in a high-temperature blow mold. Conventionally, a method of imparting heat resistance to a plug portion by heat treatment and crystallization has been performed. In this case, the time required to crystallize amorphous polyethylene terephthalate such as a plug has a large effect on productivity, so that a polyester having a high crystallization rate that can be processed in a short time is required. Further, it is required that the body does not whiten even after the heat treatment so as not to deteriorate the color tone of the filler.
[0003]
However, polyesters with excellent transparency usually crystallize slowly, so that the transparency and strength of the molded product are sacrificed, and the crystallization speed is improved by lowering the intrinsic viscosity of the resin, or the productivity is improved. And heat treatment for a long time at high temperature must be performed. When high-temperature treatment is performed for a short time heat treatment, even if whitening due to accelerated crystallization can be avoided, the amount of oligomers mainly composed of cyclic ester trimers is significantly increased inside the blow mold. In addition, the oligomer adheres to the surface of the blow mold to cause mold contamination, and whitening occurs due to roughening of the surface of the molding bottle. As a countermeasure, it is necessary to frequently clean the mold, and as a result, it does not lead to an improvement in productivity.
[0004]
In order to solve such a problem, for example, a method of improving the crystallization rate without impairing the transparency by including 0.1 to 45 ppb of polyethylene in polyester (Japanese Patent Laid-Open No. 9-151308) has been proposed. Although it has been proposed, in bottle manufacturers, the heat treatment temperature will be further increased for ultra-high speed and short-time processing will be performed, and the initial molded body's plug crystallization and body transparency are good. However, in the case of continuous molding for a long period of time, the result showed that the body part transparency tended to deteriorate over time. In particular, in recent years, the molding speed has been increasing along with the high performance of molding machines and the miniaturization of bottles, and contamination of the mold surface has become a more serious problem from the viewpoint of productivity.
[0005]
In addition, with the increase in the production speed as described above, when forming a hollow container by raising the molding temperature or heat treatment temperature, acetaldehyde (hereinafter, may be abbreviated as AA) is generated by thermal decomposition of polyester, There has been a problem that the content of acetaldehyde in the material of the obtained molded article is increased, which may adversely affect the flavor and odor of a beverage or the like filled in a hollow container or the like.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned conventional problems, and has an object to provide a polyester composition having a high crystallization rate and capable of performing a crystallization treatment stably, and also forming the polyester composition. Accordingly, it is an object of the present invention to provide a molded article having excellent flavor retention.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a polyester composition of the present invention comprises a polyester comprising 100 parts by weight of a polyester (A) whose main repeating unit is ethylene arylate, and 0.1 to 30 parts by weight of a metaxylylene group-containing polyamide (B). A composition, wherein the polyester composition has an elevated crystallization temperature of 135 to 155 ° C.
[0008]
Here, the heated crystallization temperature means a heated crystallization temperature measured by a differential scanning calorimeter.
[0009]
In this case, the acetaldehyde content in the polyester composition can be 20 ppm or less.
[0010]
In this case, the content of the cyclic ester trimer in the polyester composition can be 0.50% by weight or less.
[0011]
In this case, the amount of the cyclic ester trimer increased when the polyester composition is melted at a temperature of 290 ° C. for 60 minutes can be 0.30% by weight or less.
[0012]
Further, the molded article of the present invention is obtained by molding the polyester composition.
[0013]
In this case, the molded article can be a hollow molded article.
[0014]
Further, in this case, the molded body may be a sheet.
[0015]
Furthermore, in this case, the sheet material may be a stretched film obtained by stretching in at least one direction.
[0016]
The polyester composition of the present invention having the above configuration has a high crystallization rate, and can perform the crystallization treatment stably, and a molded article made of such a polyester composition has excellent flavor retention. ing.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the polyester composition and the molded article of the present invention will be specifically described.
[0018]
The polyester composition of the present invention is a composition comprising a polyester (A) whose main repeating unit is ethylene arylate and a polyamide containing a metaxylylene group (B). Further, the polyester composition is a dry blend in which chips of the polyester (A) and the meta-xylylene group-containing polyamide (B) are mixed, and the polyester (A) and the meta-xylylene group-containing polyamide (B) are melt-mixed. It may be a blended material.
[0019]
The polyester (A) used in the present invention is a polyester whose main repeating unit is ethylene arylate, but is preferably a linear polyester containing at least 85 mol% of ethylene arylate units, more preferably at least 90 mol%, particularly preferably at least 90 mol%. Is a linear polyester containing 95% or more. Among them, polyethylene terephthalate and polyethylene 2,6-naphthalate are preferred. Hereinafter, the case where the polyester (A) is a polyester whose main repeating unit is ethylene terephthalate will be mainly described.
[0020]
Examples of the dicarboxylic acid used as a copolymer component when the polyester (A) is a copolymer include isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, and diphenoxyethane. Aromatic dicarboxylic acids such as dicarboxylic acids and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, and glutaric acid And functional derivatives thereof, aliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, and functional derivatives thereof.
[0021]
Examples of the glycol as a copolymer component used when the polyester (A) is a copolymer include aliphatic glycols such as diethylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol; and lipids such as cyclohexane dimethanol. Examples include aromatic glycols such as cyclic glycols, bisphenol A, and alkylene oxide adducts of bisphenol A.
[0022]
Further, as the polyfunctional compound as a copolymer component used when the polyester (A) is a copolymer, trimellitic acid, pyromellitic acid and the like can be mentioned as an acid component, and as a glycol component, Glycerin and pentaerythritol can be mentioned. The amount of the above-mentioned copolymer component to be used must be such that the polyester (A) substantially maintains a linear shape. Further, a monofunctional compound such as benzoic acid or naphthoic acid may be copolymerized.
[0023]
The polyester (A) 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, an antimony compound, a germanium compound, a titanium compound and an aluminum compound are used as polycondensation catalysts. Or a direct esterification method in which polycondensation is performed under reduced pressure using one or more compounds selected from the group consisting of 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, polycondensation is carried out mainly under reduced pressure using one or more compounds selected from antimony compounds, germanium compounds, titanium compounds and aluminum compounds as polycondensation catalysts. It is produced by a transesterification method.
[0024]
Further, solid-state polymerization may be performed to increase the intrinsic viscosity of the polyester and reduce the acetaldehyde content.
[0025]
The above-mentioned esterification reaction, transesterification reaction, melt polycondensation reaction, and solid-state polymerization 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 separately.
[0026]
Examples of the antimony compound used for producing the polyester (A) used in the present invention include antimony trioxide, antimony acetate, antimony tartrate, antimony tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, triphenylantimony and the like. Can be mentioned. The antimony compound is added so that the residual amount of antimony in the produced polyester is usually in the range of 50 to 250 ppm.
[0027]
Examples of the germanium compound used for producing the polyester (A) used in the present invention include amorphous germanium dioxide, crystalline germanium dioxide, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, germanium phosphite and the like. Can be mentioned. When a germanium compound is used, the amount thereof is usually 5 to 150 ppm, preferably 10 to 100 ppm, and more preferably 15 to 70 ppm as the amount of germanium remaining in the polyester.
[0028]
Examples of the titanium compound used for producing the polyester (A) used in the present invention include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, and tetra-n-butyl titanate, and partial hydrolysis thereof. Products, titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, titanyl calcium oxalate, titanyl strontium oxalate and the like, titanium trimellitate, titanium sulfate, titanium chloride and the like. The titanium compound is added so that the amount of titanium remaining in the produced polyester is usually in the range of 0.1 to 10 ppm.
[0029]
Examples of the aluminum compound used in the production of the polyester (A) used in the present invention include carboxylate salts such as aluminum formate, aluminum acetate, aluminum propionate and aluminum oxalate, oxides, aluminum hydroxide, aluminum chloride and water. Inorganic acid salts such as aluminum oxychloride and aluminum carbonate; aluminum alkoxides such as aluminum methoxide and aluminum ethoxide; aluminum chelate compounds with aluminum acetylacetonate and aluminum acetyl acetate; and organic aluminum such as trimethylaluminum and triethylaluminum. Compounds and partial hydrolysates thereof can be mentioned. Of these, aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred. The aluminum compound is added so that the residual amount of aluminum in the produced polyester is in the range of 5 to 200 ppm.
[0030]
When an aluminum compound is used, an alkali metal compound or an alkaline earth metal compound may be used in combination. The alkali metal compound or alkaline earth metal compound includes carboxylate such as acetate of these elements, alkoxide and the like, and is added to the reaction system as powder, aqueous solution, ethylene glycol solution and the like. The alkali metal compound or alkaline earth metal compound is usually added so that the residual amount of these elements in the produced polyester is in the range of 1 to 50 ppm.
[0031]
The catalyst compound can be added at any stage of the polyester production reaction step.
[0032]
Also, various phosphorus compounds can be used as stabilizers. Examples of the phosphorus compound used in the present invention 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, phenyl phosphonate Diphenyl esters and the like, which may be used alone or in combination of two or more. The phosphorus compound is added at any stage of the polyester production reaction step so that the residual amount of phosphorus in the produced polyester is in the range of 5 to 100 ppm.
[0033]
The limiting viscosity of the polyester (A) used in the present invention is preferably 0.55 to 1.30 deciliter / gram, the lower limit is more preferably 0.58 deciliter / gram, and still more preferably 0.60 deciliter / gram, and the upper limit is It is more preferably in the range of 1.10 deciliter / gram, and even more preferably in the range of 0.90 deciliter / gram. When the intrinsic viscosity is less than 0.55 deciliter / gram, the mechanical properties of the molded product may be poor. On the other hand, if it exceeds 1.30 deciliters / gram, the resin temperature may increase during melting by a molding machine or the like, and thermal decomposition may become severe, and free low molecular weight compounds which affect the fragrance retention may increase. In some cases, problems such as the molded article being colored yellow may occur.
[0034]
The shape of the chip of the polyester (A) used in the present invention may be any of a cylinder shape, a square shape, a spherical shape, a flat plate shape and the like. The average particle size is usually in the range of 1.3 to 5 mm, preferably 1.5 to 4.5 mm, and more preferably 1.6 to 4.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.3 to 4 mm and the diameter is about 1.3 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.
[0035]
The density of the polyester (A) used in the present invention is 1.33 to 1.43 mg / cm. ³ , Preferably 1.37 to 1.42 mg / cm ³ Range.
[0036]
Generally, polyester contains a considerable amount of a copolymer component generated during the manufacturing process and fines having the same content as the polyester chip. Such fines have the property of accelerating the crystallization of polyester, and when present in a large amount, the transparency of a molded article molded from such polyester becomes extremely poor, or in the case of a bottle. However, there is a problem that the amount of shrinkage at the time of crystallization of the bottle plug portion does not fall within the specified range, and the bottle cannot be sealed with the cap.
[0037]
Therefore, the content of fines in the polyester (A) used in the present invention is desirably 500 ppm or less, preferably 300 ppm or less. If the content exceeds 500 ppm, the crystallization rate is increased, for example, the crystallization of the plug portion of the hollow molded container becomes excessively large, so that the shrinkage amount of the plug portion does not fall within the range of the specified value, Poor capping of the plug may result, causing leakage of the contents, or whitening of the preform for hollow molding, which may make normal stretching impossible.
[0038]
Further, the metaxylylene group-containing polyamide (B) used in the present invention was produced from metaxylylenediamine or a mixed xylylenediamine containing metaxylylenediamine and paraxylylenediamine of 30% or less of the total amount and dicarboxylic acid. It is a polyamide resin containing at least 70 mol%, more preferably at least 75 mol%, particularly preferably at least 80 mol% of structural units in the molecular chain.
[0039]
Examples of the dicarboxylic acid as a copolymerization component of the metaxylylene group-containing polyamide (B) include adipic acid, sebacic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, stulinic acid, azelaic acid, undecanoic acid, and undecadionic acid. , Dodecandioic acid, aliphatic dicarboxylic acids such as dimer acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, xylylenedicarboxylic acid, aromatics such as naphthalenedicarboxylic acid Dicarboxylic acids can be used.
[0040]
Examples of the diamine component as a copolymer component of the metaxylylene group-containing polyamide (B) include ethylenediamine, 1-methylethylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine. Aliphatic diamines such as octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and alicyclic diamines such as cyclohexanediamine and bis- (4,4'-aminohexyl) methane And aromatic diamines such as para-bis- (2-aminoethyl) benzene.
[0041]
As the dicarboxylic acid or diamine as a copolymer component of the meta-xylylene group-containing polyamide (B), one type or a combination of two or more types in an arbitrary ratio can be used.
[0042]
Examples of the copolymerization component of the metaxylylene group-containing polyamide (B) include, in addition to diamine and dicarboxylic acid, lactams such as ε-caprolactam and laurolactam; aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid; and para-aminomethyl. Aromatic aminocarboxylic acids such as benzoic acid can also be used as a copolymer component. In particular, use of ε-caprolactam is desirable.
[0043]
Examples of the above-mentioned metaxylylene group-containing polyamide (B) include homopolymers such as polymethaxylylene adipamide, polymethaxylylene sebacamide, polymetaxylylene speramide, and metaxylylenediamine / adipic acid / isophthalic acid. Acid copolymers, meta-xylylene / para-xylylene adipamide copolymer, meta-xylylene / para-xylylene piperamide copolymer, meta-xylylene / para-xylylene azeramide copolymer and the like can be mentioned.
[0044]
The meta-xylylene group-containing polyamide (B) is prepared by a method in which an aqueous solution of an aminocarboxylate formed from a diamine and a dicarboxylic acid is heated and reacted under pressure and normal pressure, or a direct reaction is performed by heating diamine and dicarboxylic acid under normal pressure It can be manufactured by the method of making it. In addition, by subjecting the polyamide chips obtained by these melt polycondensation reactions to solid-phase polymerization, a polyamide (B) containing a metaxylylene group having higher viscosity can be obtained. The polycondensation reaction of the above-mentioned metaxylylene group-containing polyamide (B) may be performed in a batch reactor or a continuous reactor.
[0045]
Usually, in the production of a meta-xylylene group-containing polyamide (B), in order to prevent gelation due to thermal deterioration, polymerization is often performed by adding a phosphorus-based stabilizer.
[0046]
Assuming that the phosphorus atom content in the metaxylylene group-containing polyamide (B) used in the present invention is P, the content is preferably in the range of 0.01 ≦ P ≦ 250 ppm. The lower limit is more preferably 0.1 ppm, even more preferably 1 ppm, particularly preferably 3 ppm, and most preferably 5 ppm. The upper limit is preferably 230 ppm, more preferably 200 ppm. If the phosphorus atom content (P) is less than 0.01 ppm, burning streaks and unmelted matter are liable to occur when producing a molded article. In addition, thermal degradation during molding is large, and no effect as a stabilizer can be found. On the other hand, when the phosphorus atom content (P) is more than 250 ppm, although the thermal stability is excellent, the transparency of the obtained molded article may be deteriorated. In particular, when an antimony-based compound is added to the polymerization catalyst or polyethylene terephthalate used as an additive, darkening that is considered to be derived from metal antimony occurs, and the transparency may be significantly deteriorated.
[0047]
As the compound containing a phosphorus atom in the metaxylylene group-containing polyamide (B), it is preferable to use at least one selected from compounds represented by the following chemical formulas (C-1) to (C-4).
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[0048]
(However, R ₁ ~ R ₇ Are the same or different groups, and each represents a hydrogen, an alkyl group, an aryl group, a cycloalkyl group or an arylalkyl group, X ₁ ~ X ₅ Are the same or different groups and are hydrogen, an alkyl group, an aryl group, a cycloalkyl group, an arylalkyl group or an alkali metal, or R in each formula ₁ ~ R ₇ And X ₁ ~ X ₅ One of each may be connected to each other to form a ring structure)
[0049]
Examples of the phosphinic acid compound represented by the chemical formula (C-1) include dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, and hypophosphite. Ethyl phosphate,
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And hydrolysates thereof and condensates of the above phosphinic acid compounds.
[0050]
Examples of the phosphonous acid compound represented by the chemical formula (C-2) include phenylphosphonous acid, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, and ethyl phenylphosphonite.
[0051]
Examples of the phosphonic acid compound represented by the chemical formula (C-3) include phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, and ethylphosphonate. And potassium acid.
[0052]
Examples of the phosphite compound represented by the chemical formula (C-4) include phosphorous acid, sodium hydrogen phosphite, sodium phosphite, triethyl phosphite, triphenyl phosphite, pyrophosphorous acid, and the like. .
[0053]
Further, they have found that the addition of an alkali compound represented by the following chemical formula (D) further improves the thermal stability of the polyester composition of the present invention.
Z-OR ₈ (D)
(However, Z is an alkali metal, R ₈ Is hydrogen, an alkyl group, an aryl group, a cycloalkyl group, -C (O) CH ₃ Or -C (O) OZ '(Z' is hydrogen or an alkali metal)
[0054]
Examples of the alkali compound represented by the chemical formula (D) include sodium hydroxide, sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, lithium methoxide, sodium acetate, sodium carbonate, and alkaline earth metal. And the like, but not limited to these compounds.
[0055]
The content of the alkali compound in the metaxylylene group-containing polyamide (B) used in the present invention is preferably 1.5 to 6.0 times the phosphorus atom content (P). More preferably, it is 1.8 to 5.5 times, and still more preferably, it is 2.0 to 5.0 times. When the content of the alkali compound is less than 1.5 times the phosphorus atom content (P), gelation is easily promoted. On the other hand, when the content of the alkali compound is more than 6.0 times the phosphorus atom content (P), the polymerization rate becomes slow, the viscosity does not sufficiently increase, and gelation is promoted particularly in a reduced pressure system, which is uneconomical. is there.
[0056]
The compounds represented by the chemical formulas (C-1) to (C-4) and the chemical formula (D) used in the present invention may be used alone. It is preferable because the thermal stability is improved. In addition to the above-mentioned compounds, conventionally known antioxidants, ultraviolet absorbers, weathering agents, matting agents, lubricants, viscosity stabilizers, etc. do not impair the flavor retention, gas barrier properties, and transparency of the hollow molded article. It may be used together in a degree.
[0057]
In order to mix the above-mentioned phosphorus atom-containing compound with the meta-xylylene group-containing polyamide (B) used in the present invention, it may be added as a raw material before polymerization of the polyamide, during the polymerization, or may be melt-mixed with the polymer.
[0058]
The tertiary nitrogen content of the meta-xylylene group-containing polyamide (B) used in the present invention is preferably 2.0 mol% or less, more preferably 1.5 mol% or less, and still more preferably 1.0 mol% or less. When the content of the tertiary nitrogen includes the metaxylylene group-containing polyamide (B) exceeding 2.0 mol%, the molded article contains a colored foreign substance due to a gelled substance, and the color may be deteriorated. . In particular, in a stretched film or a biaxially stretched hollow molded body obtained by stretch molding, a portion where a gel-like material is present is not stretched normally and becomes thick, causing thickness unevenness, and forming without commercial value. May have more body.
[0059]
Further, the lower limit of the tertiary nitrogen content of the metaxylylene group-containing polyamide (B) may be 0.001 mol%, further 0.01 mol%, particularly 0.05 mol% for production reasons. preferable. When producing a meta-xylylene group-containing polyamide having a tertiary nitrogen content of 0.001 mol% or less, a highly purified raw material is used, a large amount of a deterioration inhibitor is required, and the polymerization temperature is kept low. There may be a problem in productivity such as necessity.
[0060]
The term "tertiary nitrogen" used herein refers to both nitrogen based on imino groups and nitrogen based on tertiary amides, and the content of tertiary nitrogen is determined by secondary amides (-NHCO-: constituting a normal main chain). Content based on the molar ratio (mol%) to nitrogen based on the amide.
[0061]
The relative viscosity of the metaxylylene group-containing polyamide (B) used in the present invention is preferably 1.3 to 4.0, the lower limit is more preferably 1.6, still more preferably 1.7, and particularly preferably 1.8, The upper limit is more preferably 3.7, still more preferably 3.5, and particularly preferably 3.0. When the relative viscosity is less than 1.3, the molecular weight is too small, and the mechanical properties of the molded article made of the polyester composition of the present invention may be inferior. Conversely, when the relative viscosity is 4.0 or more, it takes a long time to polymerize the polyamide, which may not only cause deterioration of the polymer or undesired coloring, but also decrease productivity and increase cost. There are cases.
[0062]
The shape of the chip of the meta-xylylene group-containing polyamide (B) used in the present invention may be any of a cylinder, a square, a sphere, a flat plate, and the like. The average particle size is usually in the range of 1.0 to 5.0 mm, preferably 1.2 to 4.5 mm, and more preferably 1.5 to 4.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.0 to 4.0 mm and the diameter is about 1.0 to 4.0 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.
[0063]
The density of the metaxylylene group-containing polyamide (B) used in the present invention is 1.20 to 1.24 mg / cm. ³ And more preferably 1.20 mg / cm ³ 1.23 mg / cm ³ It is as follows.
[0064]
The mixing ratio of the polyester (A) and the meta-xylylene group-containing polyamide (B) constituting the polyester composition of the present invention is such that the meta-xylylene group-containing polyamide (B) is 0.1 part by weight based on 100 parts by weight of the polyester (A). Parts to 30 parts by weight. When the mixing amount of the metaxylylene group-containing polyamide (B) is less than 0.1 part by weight based on 100 parts by weight of the polyester (A), the crystallization promoting effect may be insufficient. Further, it is difficult to reduce the acetaldehyde content in the material of the obtained hollow container to 20 ppm or less, which may affect the flavor and odor of the filling. If the amount of the meta-xylylene group-containing polyamide (B) exceeds 30 parts by weight with respect to 100 parts by weight of the polyester (A), the effect of promoting crystallization is too large, and the transparency of the obtained molded article is extremely poor. There are cases.
[0065]
The elevated temperature crystallization temperature (hereinafter sometimes abbreviated as Tc1) of the polyester composition of the present invention needs to be in the range of 135 to 155 ° C. as measured by a differential scanning calorimeter. When the polyester composition to be measured is a blend of the polyester (A) and the meta-xylylene group-containing polyamide (B) melt-mixed, the polyester (A) and the meta-xylylene group-containing polyamide (B) are each used as a chip. In the case of a mixed dry blend, it is a blend obtained by injection molding at a molding temperature of 290 ° C.
[0066]
When Tc1 of the polyester composition of the present invention is less than 135 ° C., whitening due to crystallization is liable to occur, and heating for imparting sufficient heat resistance to the molded article cannot be performed, resulting in insufficient heat resistance or whitening. Transparency is impaired. In particular, when used in a hollow molded body, when the body of the preform is heated for blow molding, whitening due to crystallization is likely to occur, and the preform cannot be heated to the preform temperature to provide sufficient heat resistance. In some cases, the properties may be insufficient, and the shoulder and the torso may be whitened and the transparency may be impaired.
[0067]
On the other hand, when Tc1 of the polyester composition of the present invention exceeds 155 ° C., long-term heating is required in order to heat and crystallize to the desired degree of crystallinity, and the productivity tends to decrease. In particular, when the molded article is a hollow molded article, heating is required for a long time in order to heat and crystallize the plug portion to a desired crystallinity, which tends to reduce productivity.
[0068]
The acetaldehyde content in the polyester composition of the present invention is preferably 20 ppm or less, more preferably 15 ppm or less, and further preferably 10 ppm or less. When the acetaldehyde content in the polyester composition of the present invention is more than 20 ppm, the flavor and odor of a molded product, for example, a beverage filled in a hollow molded product, a sheet, a stretched film, or a contacted food, is smelled. May be adversely affected.
[0069]
The cyclic ester trimer content in the polyester composition of the present invention is preferably 0.50% by weight or less, more preferably 0.45% by weight or less, and further preferably 0.40% by weight or less. When the content of the cyclic ester trimer in the polyester composition of the present invention exceeds 0.50% by weight, the adhesion of oligomers to the surface of the heating mold rapidly increases depending on the heat treatment conditions, and The transparency of the body may be very poor, and particularly in the case of a heat-resistant hollow molded body or the like, it may be greatly affected.
[0070]
In the polyester composition of the present invention, adipic acid, one or more monomers selected from metaxylylenediamine and a cyclic body composed of adipic acid and metaxylylenediamine, or the content of the cyclic body in a free state is as follows: It is preferable that the total amount is 0.30% by weight or less. More preferably, it is 0.25% by weight or less, further preferably 0.20% by weight or less. When molding a molded article, particularly a heat-resistant hollow molded article or the like from the polyester composition of the present invention, when the content of the above monomers or cyclic bodies exceeds 0.30% by weight, the surface of the heating mold is Adhesion of monomers or cyclic bodies to the polymer may increase rapidly, and the transparency of a hollow molded article or the like may be extremely deteriorated. Further, the flavor and odor of the beverage filled in the hollow molded article or the like may be affected.
[0071]
In addition, the cyclic body composed of adipic acid and meta-xylylenediamine is a condensate of adipic acid and meta-xylylenediamine represented by the following chemical formula.
Embedded image

[0072]
Further, when the polyester composition of the present invention is melted at a temperature of 290 ° C. for 60 minutes, the amount of trimer of cyclic ester is preferably 0.50% by weight or less. The amount of the cyclic ester trimer increased is preferably 0.30% by weight or less, more preferably 0.20% by weight or less. The polyester composition having a cyclic ester trimer increase of more than 0.50% by weight when melted at a temperature of 290 ° C. for 60 minutes has an increased cyclic ester trimer when the resin is melted during molding of the polyester composition. Depending on the heat treatment conditions, the adhesion of the oligomer to the surface of the heating mold may increase rapidly, and the transparency of the hollow molded article or the like may be extremely deteriorated.
[0073]
The polyester (A) used to obtain the polyester composition of the present invention in which the cyclic ester trimer increases by 0.50% by weight or less when melted at a temperature of 290 ° C. for 60 minutes is obtained after melt polycondensation or solidification. It can be produced using a polyester in which the polycondensation catalyst remaining in the polyester obtained after the phase polymerization has been deactivated. Examples of the method of deactivating the polycondensation catalyst in the polyester 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.
[0074]
A method of contact-treating the polyester chip with water or steam, for example, steam alone, steam-containing gas or steam-containing air to achieve the above object will be described below.
[0075]
Examples of the water treatment method of the polyester chips include a method of immersing the polyester chips in water and a method of spraying water on the chips 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. The treatment method may be either a continuous method or a batch method, but a continuous method is preferable for industrial use.
[0076]
In the case of treating the polyester chips with water in a batch system, a silo-type treatment tank can be mentioned. In the case of treating the polyester chips with water in a continuous manner, the polyester chips can be continuously or intermittently received from above in a tower-type treatment tank and treated with water.
[0077]
In the case of treating by contacting the polyester chips with steam, steam at a temperature of 50 to 150 ° C., preferably 50 to 110 ° C., for example, steam alone, steam-containing gas or steam-containing air, preferably 1 kg of granular polyethylene terephthalate In this case, the granular polyethylene terephthalate is supplied in the amount of 0.5 g or more as water vapor or is brought into contact with water vapor.
[0078]
The contact between the polyester chip and the water vapor is usually performed for 10 minutes to 2 days, preferably for 20 minutes to 10 hours.
[0079]
The processing method may be either a continuous method or a batch method.
[0080]
When a polyester chip is subjected to a contact treatment with steam in a batch system, a silo-type treatment device can be used. That is, a polyester chip is received in a silo, and a contact treatment is performed by supplying steam alone, a steam-containing gas or a steam-containing air in a batch system.
[0081]
When the polyester chips are continuously subjected to the contact treatment with steam, the granular polyethylene terephthalate can be continuously received from above in a tower-type treatment device, and the steam can be continuously supplied in cocurrent or countercurrent to carry out the contact treatment with the steam.
[0082]
As described above, when treated with water or steam, the granular polyethylene terephthalate is drained with a draining device such as a vibrating sieve or a Simon Carter if necessary, and is transferred to the next drying step by a conveyor.
[0083]
Drying of the polyester chips that have been subjected to contact treatment with water or steam can be carried out by a commonly used polyester drying treatment method. As a method for continuous drying, a hopper-type through-air dryer that supplies a polyester chip from the upper portion and allows a drying gas to flow from the lower portion is usually used.
[0084]
As a dryer for drying by a batch method, drying may be performed under atmospheric pressure while passing a drying gas. Air (air) may be used as the drying gas, but dry nitrogen and dehumidified air are preferred from the viewpoint of preventing a reduction in molecular weight due to hydrolysis or thermal oxidative decomposition of the polyester.
[0085]
Further, the polyester (A) used in the present invention may be a polyester in which at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, a polyacetal resin, and a polybutylene terephthalate resin is compounded in an amount of 0.1 ppb to 1000 ppm. it can. In this case, the blending ratio of the polyolefin resin and the like in the polyester (A) used in the present invention is usually 0.1 ppb to 1000 ppm, preferably 0.3 ppb to 100 ppm, more preferably 0.5 ppb to 1 ppm, and still more preferably. Is from 0.5 ppb to 45 ppb.
[0086]
When the amount of the polyolefin resin or the like in the polyester (A) is less than 0.1 ppb, the crystallization rate tends to be slow, and the crystallization of the plug portion of the hollow molded article tends to be insufficient. If the cycle time is shortened, the capping amount may not be within the specified range due to the shrinkage of the plug part, resulting in poor capping. In order to obtain a hollow molded body, the mold must be frequently cleaned. On the other hand, when the concentration exceeds 1000 ppm, the crystallization speed is increased, and the crystallization of the plug portion of the hollow molded body may proceed. Therefore, the shrinkage amount of the plug portion does not fall within the specified value range, thus resulting in poor capping. As a result, the leakage of the contents may occur, and the preform for the hollow molded body may be whitened, so that normal stretching may not be possible. In the case of a sheet-like material, if it exceeds 1000 ppm, the transparency becomes extremely poor, and the stretchability also deteriorates, so that normal stretching is impossible, and only a stretched film with large unevenness of thickness and poor transparency is obtained. There may not be.
[0087]
Examples of the polyolefin resin that can be blended with the polyester (A) used in the present invention include a polyethylene resin, a polypropylene resin, and an α-olefin resin.
[0088]
Examples of the polyethylene resin that can be blended with the polyester (A) used in the present invention include a homopolymer of ethylene, ethylene and propylene, butene-1,3-methylbutene-1, pentene-1,4-methyl. Other α-olefins having about 2 to 20 carbon atoms such as pentene-1, hexene-1, octene-1, decene-1, and the like, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylate, methacrylate And a copolymer with a vinyl compound such as styrene. Specifically, for example, ethylene homopolymer such as low / medium / high density polyethylene (branched or linear), ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-4-methyl Pentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene -Ethylene resins such as ethyl acrylate copolymer.
[0089]
Examples of the polypropylene resin that can be blended with the polyester (A) used in the present invention include, for example, propylene homopolymer, propylene, ethylene, butene-1,3-methylbutene-1, pentene-1,4 -Other α-olefins having about 2 to 20 carbon atoms such as methylpentene-1, hexene-1, octene-1, decene-1 and the like, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylate, methacrylic acid Copolymers with vinyl compounds such as acid esters and styrene can be exemplified. Specifically, for example, propylene-based resins such as propylene homopolymer, propylene-ethylene copolymer, and propylene-ethylene-butene-1 copolymer can be exemplified.
[0090]
Examples of the α-olefin resin that can be blended with the polyester (A) used in the present invention include homopolymers of α-olefins having about 2 to 8 carbon atoms such as 4-methylpentene-1 and α-olefins thereof. Olefin and other α-olefins having about 2 to 20 carbon atoms such as ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1. Polymers and the like can be mentioned. 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; A copolymer of -methylpentene-1 and a C2-C18 α-olefin;
[0091]
Examples of the polyamide resin that can be blended with the polyester (A) used in the present invention include lactam polymers such as butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, and ω-laurolactam; Polymers of aminocarboxylic acids such as aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- Or an aliphatic diamine such as 2,4,4-trimethylhexamethylenediamine, an alicyclic diamine such as 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- Or an aromatic diamine such as p-xylylenediamine Diamine units, and aliphatic dicarboxylic acids such as glutaric acid, adipic acid, suberic acid, and sebacic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; terephthalic acid; and dicarboxylic acid units such as aromatic dicarboxylic acids such as isophthalic acid. And a copolymer thereof, and specifically, for example, nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, nylon 611, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6/66, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T, and the like.
[0092]
Examples of the polyacetal resin that can be blended with the polyester (A) used in the present invention include, for example, polyacetal homopolymers and copolymers. As the polyacetal homopolymer, the density measured by the measurement method of ASTM-D792 is 1.40 to 1.42 g / cm. ³ A polyacetal homopolymer having a melt index (MI) in the range of 0.5 to 50 g / 10 minutes measured at 190 ° C. under a load of 2160 g by ASTM-1238 is preferable.
[0093]
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 index (MI) of from 0.4 to 50 g / 10 min, measured at 190 ° C. under a load of 2160 g, according to the measurement method of ASTM D-1238 is preferable. Examples of the copolymer component of polyacetal include ethylene oxide and cyclic ether.
[0094]
Examples of the polybutylene terephthalate resin that can be blended with the polyester (A) used in the present invention include, for example, a polybutylene terephthalate homopolymer composed of terephthalic acid and 1,4-butanediol, naphthalenedicarboxylic acid, diethylene glycol, Copolymers obtained by copolymerizing 1,4-cyclohexanedimethanol and the like can be given.
[0095]
The polyester (A) containing the polyolefin resin, the polyamide resin, the polyacetal resin or the polybutylene terephthalate resin, which can be used in the present invention, contains the polyester (A) and the resin such as the polyolefin resin. In such a manner that the amount falls within the above range, a method of directly adding and melt-kneading, or a method of adding and melting and kneading as a masterbatch can be obtained by a conventional method such as a resin, such as the polyolefin resin, Any of the steps of producing the polyester (A), for example, during melt polycondensation, immediately after melt polycondensation, immediately after pre-crystallization, during solid phase polymerization, immediately after solid phase polymerization, or after finishing the production step It can be added directly as a powder before the molding stage, or under the flow conditions of polyester chips. After mixed by a method such as contacting a resin member of serial such polyolefin resins can also be obtained by a method in which melt kneading.
[0096]
Here, as a method of bringing the polyester chip into contact with a resin member such as the polyolefin resin under the flow condition, the polyester chip is attached to the member in a space where the resin member such as the polyolefin resin exists. It is preferable to carry out collision contact.Specifically, for example, immediately after melt polycondensation of polyester, immediately after pre-crystallization, immediately after solid-state polymerization, etc., during the production process, or during transportation of polyester chips as a product, etc. At the time of container filling / discharging, or a part of a pneumatic transport pipe, a gravity transport pipe, a silo, a magnet part of a magnet catcher and the like made of a resin such as the above-mentioned polyolefin resin at the time of injection of a molding machine at a polyester chip molding stage. Or lining a resin such as the above-mentioned polyolefin resin, or a rod-shaped resin in the transfer path. Is equal installing a resin member such as the polyolefin resin of the mesh body or the like can be mentioned a method of transferring the polyester chips. The contact time of the polyester chip with the member is usually as short as about 0.01 second to several minutes, but a small amount of the resin such as the polyolefin resin can be mixed into the polyester (A).
[0097]
Further, the acetaldehyde content of the polyester (A) used in the present invention is 10 ppm or less, preferably 8 ppm or less, more preferably 6 ppm or less, still more preferably 4 ppm or less, and the formaldehyde content is 6 ppm or less, preferably 5 ppm or less, more preferably Desirably, it is 4 ppm or less. When the acetaldehyde content exceeds 10 ppm and the formaldehyde content exceeds 6 ppm, the effect of retaining the flavor of the contents such as molded articles tends to be low. The lower limits of the acetaldehyde content and the formaldehyde content are each preferably 0.1 ppb.
[0098]
The lower limit of the amount of diethylene glycol copolymerized in the polyester (A) used in the present invention is preferably 1.0 mol%, more preferably 1.3 mol%, more preferably 1.3 mol%. It is preferably 1.5 mol%, and the upper limit is preferably 5.0 mol%, more preferably 4.5 mol%, and still more preferably 4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability tends to be poor, and the decrease in the molecular weight during molding is large, and the increase in the acetaldehyde content and the formaldehyde content is large. There is not preferred. When the diethylene glycol content is less than 1.0 mol%, the transparency of the molded article may be deteriorated.
[0099]
The polyester composition of the present invention can be obtained by mixing the above-mentioned polyester (A) and the above-mentioned metaxylylene group-containing polyamide (B) by a conventionally known method. For example, the polyamide chip and the polyester chip are dry-blended with a tumbler, a V-blender, a Henschel mixer, or the like, and the dry-blended mixture is melted at least once with a single-screw extruder, a twin-screw extruder, a kneader, or the like. Examples thereof include those obtained by mixing, and, if necessary, those obtained by subjecting a molten mixture to solid-phase polymerization under a high vacuum or an inert gas atmosphere.
[0100]
It is also possible to simultaneously add saturated fatty acid monoamide, unsaturated fatty acid monoamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide and the like to the polyester composition of the present invention.
[0101]
Examples of the saturated fatty acid monoamide that can be added in combination to the polyester composition include lauric amide, palmitic amide, stearic amide, behenic amide and the like. Examples of the unsaturated fatty acid monoamide that can be added in combination include oleic amide, erucic amide, ricinoleic amide, and the like. Examples of the saturated fatty acid bisamide that can be added in combination include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide. Acid amide, hexamethylenebisbehenic acid amide and the like can be mentioned. Examples of the unsaturated fatty acid bisamide that can be added in combination 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 It is preferably in the ppm range.
[0102]
Further, a metal salt compound of an aliphatic monocarboxylic acid having 8 to 33 carbon atoms, for example, naphthenic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid is added to the polyester composition. Lithium, sodium, potassium, magnesium, calcium, cobalt salts and the like of saturated and unsaturated fatty acids such as melocyanic acid, oleic acid, linoleic acid and the like can be simultaneously added. The compounding amount of these compounds is preferably in the range of 10 ppb to 300 ppm.
[0103]
The polyester composition of the present invention, if necessary, other additives, for example, known ultraviolet absorbers, antioxidants, oxygen absorbers, oxygen scavengers, lubricants added from the outside and internal precipitation during the reaction. Various additives such as a lubricant, a release agent, a nucleating agent, a stabilizer, an antistatic agent, and a pigment may be blended. It is also possible to mix an ultraviolet ray blocking resin, a heat resistant resin, a product recovered from a used polyethylene terephthalate bottle, and the like at an appropriate ratio.
[0104]
In addition, when the polyester composition of the present invention is used for a sheet-like material, particularly for a film application, calcium carbonate is contained in the polyester composition in order to improve handling properties such as slipperiness, winding property, and blocking resistance. Inorganic particles such as magnesium carbonate, barium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, and magnesium phosphate; and organic salt particles such as calcium and oxalate, terephthalate such as barium, zinc, manganese, and magnesium; Inert particles such as crosslinked polymer particles such as homo- or copolymers of vinyl monomers of divinylbenzene, styrene, acrylic acid, methacrylic acid, acrylic acid or methacrylic acid can be contained.
[0105]
The polyester composition of the present invention can be used to form a molded product such as a film, a sheet, a container, and other packaging materials using a generally used melt molding method. The stretched film made of the polyester composition of the present invention is obtained by subjecting a sheet obtained by injection molding or extrusion molding to uniaxial stretching or sequential biaxial stretching used for stretching ordinary polyethylene terephthalate (hereinafter sometimes abbreviated as PET). It is molded using any stretching method such as axial stretching and simultaneous biaxial stretching. Further, it can be formed into a reclip shape or a tray shape by pressure forming or vacuum forming.
[0106]
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, the stretching direction 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 to 240 ° C., preferably 150 to 230 ° C., usually for several seconds to several hours, preferably for several tens seconds to several minutes.
[0107]
In producing the hollow molded article, the molded preform can be produced by stretch blow molding, and an apparatus conventionally used for blow molding of polyester 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 as it is, it is reheated, and biaxial stretching blow such as hot parison method or cold parison method is performed. It can be molded by applying a molding method. In this case, the molding temperature, specifically, the temperature of each part of the cylinder and the nozzle of the molding machine is usually in the range of 260 to 290 ° 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 that require hot filling, such as fruit juice beverages, oolong tea, etc., generally, heat-setting treatment is further performed in a blow mold to obtain heat resistant It is used with imparting properties. The heat setting is generally performed at 100 to 200 ° C., preferably 120 to 180 ° C., for several seconds to several hours, preferably several seconds to several minutes, under tension by compressed air or the like.
[0108]
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 an oven equipped with a far-infrared or near-infrared heater, or the bottle is formed after the bottle is formed. The stopper is crystallized by the heater.
[0109]
Further, the polyester composition of the present invention can also be used as one constituent layer of a laminated molded article, a laminated film, or the like. In particular, it is used in the production of containers and the like in the form of a laminate with PET. Examples of the laminated molded article include a two-layer structure composed of an outer layer made of the polyester composition of the present invention and a PET inner layer or a two-layer structure composed of an inner layer made of the polyester composition of the present invention and a PET outer layer. Molded article having a two-layer structure, a three-layer structure comprising an intermediate layer containing the polyester composition of the present invention and an outer layer and innermost layer of PET, or an intermediate layer between the outer layer and the innermost layer containing the polyester composition of the present invention and PET. A molded article having a three-layer structure composed of layers, a molded article having a five-layer structure composed of an intermediate layer containing the polyester composition of the present invention and an innermost layer, a central layer, and an outermost layer of PET can be given. For the PET layer, other gas barrier resins, ultraviolet blocking resins, heat resistant resins, and products recovered from used polyethylene terephthalate bottles can be mixed and used at an appropriate ratio.
[0110]
In addition, examples of other laminated molded articles include a laminated molded article with a resin other than polyester such as polyolefin, and a laminated molded article with a different kind of base material such as paper or a metal plate.
[0111]
There are no particular restrictions on the thickness of the laminate and the thickness of each layer. In addition, the laminated molded article can be used in various shapes such as a sheet, a film, a plate, a hollow body, and a container.
[0112]
The production of the laminated molded article can be carried out by co-extrusion using a number of extruders and multilayer dies corresponding to the type of the resin layer, or a number of injection machines corresponding to the type of the resin layer. And co-injection using a co-injection runner and an injection mold.
[0113]
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.
[0114]
Further, the composition of the present invention can also be used for cooking food in a microwave oven and / or a microwave oven, or for use as a tray-shaped container for heating frozen food. In this case, after the sheet-like material from the polyester composition is formed into a tray shape, it is thermally crystallized to improve heat resistance.
[0115]
【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.
[0116]
(Evaluation method)
(1) Intrinsic viscosity of polyester (hereinafter referred to as "IV")
It was determined from the solution viscosity at 30 ° C. in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent.
[0117]
(2) Diethylene glycol content copolymerized in polyester (hereinafter referred to as [DEG content])
It was decomposed with methanol, and the amount of DEG was quantified by gas chromatography and expressed as a ratio (mol%) to the total glycol component.
[0118]
(3) Cyclic ester 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 is added 15 mL of methanol to precipitate the polymer, which is then filtered. The filtrate was evaporated to dryness, the volume was adjusted to 10 mL with dimethylformamide, and the cyclic ester trimer was quantified by high performance liquid chromatography.
[0119]
(4) Acetaldehyde content (hereinafter referred to as "AA content")
A sample / distilled water = 1 g / 2 mL was placed in a glass ampoule purged with nitrogen, the upper part was sealed, extracted at 160 ° C. for 2 hours, cooled, and the acetaldehyde in the extract was measured by high-sensitivity gas chromatography. The concentration was expressed in ppm.
[0120]
(5) Cyclic ester trimer increase during melting (hereinafter referred to as “ΔCT amount”)
3 g of the dried sample 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 the cyclic ester trimer increased during melting was determined by the following equation.
ΔCT amount during melting (% by weight) = (CT amount after melting (% by weight) −CT amount before melting (% by weight))
[0121]
(6) Forming a stepped plate
The dehumidified and dried polyester composition is molded using an injection molding machine (M-150C (DM)) manufactured by Meiki Seisakusho at a cylinder temperature of 290 ° C using a stepped flat mold cooled to 10 ° C. The obtained stepped plate is provided with a stepped plate of about 3 cm × about 5 cm square having a thickness of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 mm. The weight of one plate is about 146 g. The plate part having a thickness of 2 mm was used for measurement of the temperature rise crystallization temperature (Tc1).
[0122]
(7) Temperature rise crystallization temperature
The measurement was performed at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC) (RDC-220) manufactured by Seiko Instruments Inc. The top temperature of the crystallization peak observed during the temperature rise from room temperature was defined as the temperature rise crystallization temperature (Tc1). The polyester composition to be measured is 10 mg. If the polyester (A) and the meta-xylylene group-containing polyamide (B) are melt-mixed, this blend is used. Alternatively, the polyester (A) and the meta-xylylene group-containing polyamide (B) are mixed. When each chip was a mixed dry blend, it was molded in the above (6), and the blend at the center of a 2 mm-thick plate of the resulting molded plate was used.
[0123]
(8) Density of plug
An injection molding machine (M-150C) manufactured by Meiki Seisakusho Co., Ltd. was used by using a predetermined amount of a polyester chip dried by a drier using nitrogen gas and a predetermined amount of a meta-xylylene group-containing polyamide chip dried by a drier using nitrogen gas. (DM)) to form a preform at a resin temperature of 290 ° C. The temperature of the preform near the plug was adjusted to 180 ° C. with a near-infrared quartz heater, and the preform was heated for 90 seconds while rotating the preform with a plug crystallization apparatus. The density at the surface thread start position was measured. The density was determined by dissolving calcium nitrate in pure water in a density gradient tube (density range: 1.28 to 1.42 g / cm). ³ ) Was prepared and measured at a value of 2 hours after being charged at a temperature of 30 ° C.
[0124]
(9) Evaluation of mold contamination
An injection molding machine (M-150C) manufactured by Meiki Seisakusho Co., Ltd. was used by using a predetermined amount of a polyester chip dried by a drier using nitrogen gas and a predetermined amount of a meta-xylylene group-containing polyamide chip dried by a drier using nitrogen gas. (DM)) to form a preform at a resin temperature of 290 ° C. After the plug part of this preform was heated and crystallized by a plug part crystallizer manufactured by Toyobo Co., Ltd., biaxial stretch blow molding was performed using a stretch blow molding machine (LB-01E) manufactured by Corpoplast, Subsequently, the mixture was heat-set in a mold set at about 155 ° C. for about 10 seconds to obtain a hollow molded body having a volume of 1000 mL. The stretch blow molding was continuously performed under the same conditions, and the stain on the mold was evaluated by the number of moldings until the transparency of the molded article was impaired by visual judgment.
[0125]
(10) Transparency of hollow molded body
The appearance of the hollow molded body obtained after the 3,000 moldings in the above (9) was visually observed and evaluated as follows.
：: transparent, no unmelted material
×: Poor transparency or unmelted material
[0126]
(11) Sensory test
Boiling distilled water was placed in the above hollow molded body, kept for 30 minutes after sealing, cooled to room temperature, allowed to stand at room temperature for one month, opened, and tested for flavor, smell and the like. Distilled water was used as a blank for comparison. The sensory test was carried out by 10 panelists according to the following criteria, and the average value was compared.
(Evaluation criteria)
0: No off-flavor or smell
1: Slight difference from blank
2: Feel the difference from the blank
3: I feel a considerable difference from the blank
4: I feel a very large difference from the blank
[0127]
(Polyethylene terephthalate (PET) used in Examples and Comparative Examples)
Table 1 shows the characteristics of PET (remaining amount of germanium = about 40 to 50 ppm, remaining amount of phosphorus = about 30 to 35 ppm) used in the test. These are all polymerized by a continuous melt polycondensation-solid state polymerization apparatus.
-PET (a): After solid-phase polymerization, subjected to hot water treatment in ion-exchanged water at about 90 ° C for 3 hours.
-PET (b): those not subjected to hot water treatment after solid phase polymerization.
The DEG content of PET (a) and PET (b) was about 2.7 mol%.
[0128]
[Table 1]

[0129]
(Metaxylylene group-containing polyamide (MXD6) used in Examples and Comparative Examples) For the test, Toyobo Co., Ltd. MXD6 (T-600 (relative viscosity RV = 2.1)) was used.
[0130]
[Table 2]

[0131]
(Example 1)
Using 0.5 parts by weight of MXD6 with respect to 100.0 parts by weight of PET (a), melting was performed by the method of evaluation method (5), and the amount of ΔCT was measured. Also, the method of evaluation method (6) was used. And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0132]
(Example 2)
Using 10 parts by weight of PET (a), 3.0 parts by weight of MXD6 was melted by the method of evaluation method (5) to measure the amount of ΔCT, and the method of evaluation method (6) And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0133]
(Example 3)
Using 5.0 parts by weight of MXD6 with respect to 100.0 parts by weight of PET (a), melting was carried out by the method of evaluation method (5), the amount of ΔCT was measured, and the method of evaluation method (6) was used. And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0134]
(Example 4)
Using 20.0 parts by weight of MXD6 with respect to 100.0 parts by weight of PET (a), melting was carried out by the method of evaluation method (5), the amount of ΔCT was measured, and the method of evaluation method (6) was used. And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0135]
(Comparative Example 1)
Using 0.01 part by weight of MXD6 with respect to 100.0 parts by weight of PET (a), melt by the method of evaluation method (5), measure the amount of ΔCT, and also use the method of evaluation method (6). And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0136]
(Comparative Example 2)
Using 10 parts by weight of PET (b), 3.0 parts by weight of MXD6 was melted by the method of evaluation method (5) to measure the ΔCT amount, and the method of evaluation method (6) And a Tc1 of the formed plate (2 mm thick plate portion) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0137]
(Comparative Example 3)
Using only PET (a), it is melted by the method of the evaluation method (5), the amount of ΔCT is measured, and a stepped plate is formed by the method of the evaluation method (6). The Tc1 of a 2 mm thick plate) was measured. Further, a preform was formed by the method of the evaluation method (8), and the plug portion of the preform was subjected to crystallization treatment to measure the plug density. Further, a hollow molded article was molded by the method of the evaluation method (9), and the transparency, CT content, and AA content of the hollow molded article were measured. In addition, transparency measured the trunk part of the hollow molded body, CT content, and AA content measured the plug part. In addition, mold stain evaluation and sensory test evaluation were also performed. Table 2 shows the evaluation results of the obtained molded bodies.
[0138]
【The invention's effect】
According to the polyester composition of the present invention, the crystallization speed is high, and the crystallization treatment can be performed stably, and according to the molded product obtained from such a polyester composition, the flavor retention Are better.

Claims (8)

A polyester composition comprising 100 parts by weight of a polyester (A) whose main repeating unit is ethylene arylate, and 0.1 to 30 parts by weight of a polyamide containing a metaxylylene group (B), wherein the polyester composition is heated and crystallized. A polyester composition having a temperature of 135 to 155 ° C. The polyester composition according to claim 1, wherein the acetaldehyde content is 20 ppm or less. The polyester composition according to claim 1 or 2, wherein the cyclic ester trimer content is 0.50% by weight or less. 4. The polyester composition according to claim 1, wherein the amount of the cyclic ester trimer increased by melting at a temperature of 290 ° C. for 60 minutes is 0.50% by weight or less. A molded article obtained by molding the polyester composition according to claim 1, 2, 3, or 4. The molded article according to claim 5, which is a hollow molded article. The molded article according to claim 5, wherein the molded article is a sheet. The molded article according to claim 7, wherein the sheet is a stretched film stretched in at least one direction.