JP2004231831A - Method for manufacturing polyester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyester having excellent esterification and/or polycondensation reactivity, a good color tone, little DEG content and good spinnability. <P>SOLUTION: This method for manufacturing a polyester comprises polycondensation of a product obtained by an esterification reaction of terephthalic acid and ethylene glycol as a main component, wherein a titanium compound, the substituent of which has at least one radical selected from the group consisting of specific functional radicals, is used as an esterification and/or a polycondensation catalyst, and at least one alkali compound selected from the group consisting of a quaternary ammonium compound, potassium hydroxide and sodium hydroxide is added. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００１６】
【化１４】

【００１７】
【化１５】

【００１８】
【化１６】

【００１９】
【化１７】

【００２０】
【化１８】

【００２１】
（式１〜式６中、Ｒ_１〜Ｒ_３はそれぞれ独立に水素、炭素数１〜３０の炭化水素基、アルコキシ基または水酸基またはカルボニル基またはアセチル基またはカルボキシル基またはエステル基またはアミノ基を有する炭素数１〜３０の炭化水素基を表す。）
【００２２】
【発明の実施の形態】
本発明のポリエステルは、芳香族ジカルボン酸であるテレフタル酸とエチレングリコールを主成分とするジオールから構成される。
【００２３】
本発明のポリエステルには、ジエチレングリコール以外に共重合成分としてアジピン酸、イソフタル酸、セバシン酸、フタル酸、ナフタレンジカルボン酸、４，４’−ジフェニルジカルボン酸、シクロヘキサンジカルボン酸等のジカルボン酸及びそのエステル形成性誘導体、ポリエチレングリコール、ヘキサメチレングリコール、ネオペンチルグリコール、ポリプロピレングリコール、シクロヘキサンジメタノール等のジオキシ化合物、ｐ−（β−オキシエトキシ）安息香酸等のオキシカルボン酸及びそのエステル形成性誘導体等が共重合されていてもよい。
【００２４】
本発明における重合用触媒としてのチタン化合物は、置換基が下記一般式１〜式６で表される官能基からなる群より選ばれる少なくとも１種であるチタン化合物であることが必要である。
【００２５】
【化１９】

【００２６】
【化２０】

【００２７】
【化２１】

【００２８】
【化２２】

【００２９】
【化２３】

【００３０】
【化２４】

【００３１】
（式１〜式６中、Ｒ_１〜Ｒ_３はそれぞれ独立に水素、炭素数１〜３０の炭化水素基、アルコキシ基または水酸基またはカルボニル基またはアセチル基またはカルボキシル基またはエステル基またはアミノ基を有する炭素数１〜３０の炭化水素基を表す。）
本発明の式１としては、エトキシド、プロポキシド、イソプロポキシド、ブトキシド、２−エチルヘキソキシド等のアルコキシ基、乳酸、リンゴ酸、酒石酸、クエン酸等のヒドロキシ多価カルボン酸系化合物からなる官能基が挙げられる。 式２としては、アセチルアセトン等のβ−ジケトン系化合物、アセト酢酸メチル、アセト酢酸エチル等のケトエステル系化合物からなる官能基が挙げられる。
【００３２】
式３としては、フェノキシ、クレシレイト、サリチル酸等からなる官能基が挙げられる。
【００３３】
式４としては、ラクテート、ステアレート等のアシレート基、フタル酸、トリメリット酸、トリメシン酸、ヘミメリット酸、ピロメリット酸、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、セバシン酸、マレイン酸、フマル酸、シクロヘキサンジカルボン酸またはそれらの無水物等の多価カルボン酸系化合物、エチレンジアミン四酢酸、ニトリロ三プロピオン酸、カルボキシイミノ二酢酸、カルボキシメチルイミノ二プロピオン酸、ジエチレントリアミノ五酢酸、トリエチレンテトラミノ六酢酸、イミノ二酢酸、イミノ二プロピオン酸、ヒドロキシエチルイミノ二酢酸、ヒドロキシエチルイミノ二プロピオン酸、メトキシエチルイミノ二酢酸等の含窒素多価カルボン酸からなる官能基が挙げられる。
【００３４】
式５としては、アニリン、フェニルアミン、ジフェニルアミン等からなる官能基が挙げられる。また、これらの置換基を２種含んでなるジイソプロポキシビスアセチルアセトンやトリエタノールアミネートイソプロポキシド等が好ましく挙げられる。
【００３５】
なかでも式１及び／又は式４が含まれていることがポリマーの熱安定性および色調の観点から好ましい。
【００３６】
また、チタン化合物としてこれら式１〜式６の置換基の２種以上を含んでなるチタンジイソプロポキシビスアセチルアセトナートやチタントリエタノールアミネートイソプロポキシド等が挙げられる。
【００３７】
本発明における触媒としてのチタン化合物は、得られるポリマーに対してチタン原子換算で０．５〜１５０ｐｐｍ添加するとエステル化反応や重合活性が高く、得られるポリマーの溶融耐熱性や色調が良好となり好ましい。より好ましくは１〜１００ｐｐｍ、更に好ましくは３〜５０ｐｐｍである。
【００３８】
本発明の触媒としてのチタン化合物は、ポリエステルの反応系にそのまま添加してもよいが、予め該化合物をエチレングリコール等のポリエステルを形成するジオール成分を含む溶媒と混合し、溶液またはスラリーとし、必要に応じて該化合物合成時に用いたアルコール等の低沸点成分を除去した後、反応系に添加すると、ポリマー中での異物生成がより抑制されるため好ましい。添加時期はエステル化反応触媒として、原料添加直後に触媒を添加する方法や、原料と同伴させて触媒を添加する方法がある。また、重縮合反応触媒として添加する場合は、実質的に重縮合反応開始前であればよく、エステル化反応の前、あるいは該反応終了後、重縮合反応触媒が開始される前に添加してもよい。
【００３９】
なお、本発明の触媒とは、ジカルボン酸またはそのエステル形成性誘導体及びジオールまたはそのエステル形成性誘導体から合成されるポリマーにおいて、以下の（１）（２）の反応全てまたは一部の素反応の反応促進に実質的に寄与する化合物を指す。
（１）ジカルボン酸成分とジオール成分との反応であるエステル化反応
（２）実質的にエステル反応が終了し、得られたポリエチレンテレフタレート低重合体を脱ジオール反応にて高重合度化せしめる重縮合反応
本発明のアルカリ化合物は、第４級アンモニウム化合物、水酸化カリウムおよび水酸化ナトリウムからなる群から選ばれる少なくとも１種のアルカリ化合物であることが必要である。
【００４０】
本発明において、これら第４級アンモニウム化合物、水酸化カリウムおよび水酸化ナトリウムからなる群から選ばれる少なくとも１種のアルカリ化合物のうち、第４級アンモニウム化合物を用いると、得られるポリエステルの色調が特に良好
となることから好ましく、また、２８０℃以下の温度で揮発する化合物であることから、最終的に得られるポリエステル中の残留量が少なくなり、ポリマー中に異物となることがなく、好ましい。
【００４１】
本発明の好ましい第４級アンモニウム化合物は、例えば次の式７で表される化合物を挙げることができる。
【００４２】
【化２５】

【００４３】
（但し、式７中、Ｒ_１ 、Ｒ_２ 、Ｒ_３および Ｒ_４ は水素原子、アルキル基、アリー
ル基、アリル基から選ばれる基を表す。）
より具体的には、式７の化合物としては、水酸化テトラメチルアンモニウム、水酸化テトラエチルアンモニウム（以下ＥＡＨという）、水酸化テトラプロピルアンモニウム、水酸化テトラブチルアンモニウム、水酸化トリメチルベンジルアンモニウム、等を挙げることができる。
【００４４】
本発明のアルカリ化合物の添加量は、第４級アンモニウム化合物の場合には、得られるポリエステルに対して１０〜３０００ｐｐｍであることが好ましい。１０ｐｐｍ以上であると、ポリマーの色調の改善、重合反応時の副反応の抑制によるＤＥＧ量増加の抑制効果が十分に発揮される。一方、特に、３０００ｐｐｍ以下であると、ポリマーの色調も良好である。添加量としては、２０〜２０００ｐｐｍがより好ましく、さらに好ましくは５０〜１０００ｐｐｍである。また、水酸化ナトリウム、水酸化カリウムの場合には０．１〜１００ｐｐｍであることが好ましい。０．１ｐｐｍ以上であると、ポリマーの色調の改善、重合反応時の副反応の抑制によるＤＥＧ量増加の抑制効果が十分に発揮される。一方、特に、１００ｐｐｍ以下であると、エステル化反応や重縮合反応の遅延はなく良好である。添加量としては、０．５〜５０ｐｐｍがより好ましく、さらに好ましくは１〜２０ｐｐｍである。
【００４５】
本発明におけるアルカリ化合物の添加時期は、エステル化反応開始前、エステル化反応中、エステル化反応後、および／又は重縮合開始前等であるが、特に限定されるものではなく、エステル化反応前と重縮合前に分割添加してもよい。チタン化合物の添加前、又はチタン化合物と同時に添加するのが、得られるポリマーの色調、ＤＥＧ量の抑制効果の点から好ましい。
【００４６】
また、本発明で用いるチタン化合物を、アルカリ化合物を含有する水、有機溶媒、又は水および有機溶媒の混合物で予め処理し、得られた処理液を添加すると、チタン化合物が均一に分散あるいは溶解し、ポリマー中での異物生成が抑制されるため好ましい。また、このチタン化合物を含有する処理液が水溶液の場合にはエチレングリコール等のポリエステルを形成するジオール成分で希釈した後、反応系に添加すると、急激な温度変化による局部的な濃縮などが起こりにくくなるため、不溶性異物の生成がなく、好ましい。
【００４７】
このようにチタン化合物を予めアルカリ化合物を含有する水、有機溶媒、又は水および有機溶媒の混合物で予め処理する場合には、水、有機溶媒、又は水および有機溶媒の混合物に対して、アルカリ化合物の濃度が、０．０５〜２０重量％、より好ましくは０．１〜１０重量％にすると、その後に添加するチタン化合物が分散あるいは溶解がより容易に進行するため好ましい。
【００４８】
本発明のチタン化合物を予めリン化合物と反応させた触媒とする場合には、（１）チタン化合物を溶媒に混合してその一部または全部を溶媒中に溶解し、この混合溶液にリン化合物を原液または溶媒に溶解希釈させ滴下する。（２）前記ヒドロキシカルボン酸系化合物や多価カルボン酸系化合物等のチタン化合物の配位子を用いる場合は、チタン化合物または配位子化合物を溶媒に混合してその一部または全部を溶媒中に溶解し、この混合溶液に配位子化合物またはチタン化合物を原液または溶媒に溶解希釈させ滴下する。また、この混合溶液にさらにリン化合物を原液または溶媒に溶解希釈させ滴下すると、熱安定性及び色調改善の観点から好ましい。上記の反応条件は０〜２００℃の温度で１分以上、好ましくは２０〜１００℃の温度で２〜１００分間加熱することによって行われる。この際の反応圧力には特に制限はなく、常圧でも良い。また、上記溶媒としては、チタン化合物、リン化合物及びカルボニル基含有化合物の一部または全部を溶解し得るものから選択することができるが、好ましくは、水、メタノール、エタノール、エチレングリコール、プロパンジオール、ブタンジオール、ベンゼン、キシレンから選ばれる。
【００４９】
また、本発明のポリエステルは、製糸時におけるポリエステルの熱安定性や色調の観点から、チタン化合物と共にリンをポリエステルに対してリン原子換算で０．１〜４００ｐｐｍ含有されるように重合開始前、又はそれ以前の段階で添加してもよい。このようなリン化合物としてはリン酸系、亜リン酸系、ホスホン酸系、ホスフィン酸系、ホスフィンオキサイド系、亜ホスホン酸系、亜ホスフィン酸系、ホスフィン系のいずれか１種または２種であることが好ましい。具体的には、例えば、リン酸、リン酸トリメチル、リン酸トリエチル、リン酸トリフェニル等のリン酸系、亜リン酸、亜リン酸トリメチル、亜リン酸トリエチル、亜リン酸トリフェニル等の亜リン酸系、メチルホスホン酸、エチルホスホン酸、プロピルホスホン酸、イソプロピルホスホン酸、ブチルホスホン酸、フェニルホスホン酸などが好ましく用いられる。リン含有量は、１〜２００ｐｐｍが好ましく、さらに好ましくは３〜１００ｐｐｍである。
【００５０】
なお、チタン化合物のチタン原子に対してリン原子としてモル比率でＴｉ／Ｐ＝０．１〜２０であるとポリエステルの熱安定性や色調が良好となり好ましい。より好ましくはＴｉ／Ｐ＝０．２〜１０であり、さらに好ましくはＴｉ／Ｐ＝０．３〜５である。
【００５１】
本発明のポリエステルにおいてはアンチモン化合物の含有量が金属原子換算で５０ｐｐｍ以下であることが必要である。この範囲とすることで、成形加工時の口金汚れの発生等が少なく、かつ比較的安価なポリマーを得ることができる。より好ましくは、２０ｐｐｍ以下、特には実質的に含有しないことが好ましい。
【００５２】
また、従来公知の酸化チタン、酸化ケイ素、炭酸カルシウム、チッ化ケイ素、クレー、タルク、カオリン、カーボンブラック等の顔料のほか、従来公知の着色防止剤、安定剤、抗酸化剤等の添加剤を含有しても差支えない。
【００５３】
本発明のポリエステルは以下のような方法によって得られる。
【００５４】
例えば、テレフタル酸とエチレングリコールを原料とし、直接エステル化反応によって低重合体を得、さらにその後の重縮合反応によって高分子量ポリマーを製造する。
【００５５】
ここで、エステル化、および／又は重縮合触媒として本発明のチタン化合物を使用し、かつ、第４級アンモニウム化合物、水酸化カリウム、および水酸化ナトリウムからなる群から選ばれる少なくとも１種のアルカリ化合物を添加するが、少量のアンチモン化合物、スズ化合物、ゲルマニウム化合物、あるいはマンガン、コバルト、亜鉛などの化合物を触媒に用いて進行させてもよい。なお、エステル化反応は無触媒でも反応は進行するが、本発明のチタン化合物を触媒として添加してもよい。
【００５６】
本発明の製造方法は、一連の反応の任意の段階、好ましくは一連の反応の前半で得られた低重合体に、艶消し剤として酸化チタン粒子や、コバルト化合物等の添加物を添加した後、重縮合触媒として本発明のチタン化合物を添加し重縮合反応を行い、高分子量のポリエチレンテレフタレートを得てもよい。
【００５７】
また、上記の反応は回分式、半回分式あるいは連続式等の形式で実施されるが、本発明の製造方法はそのいずれの形式にも適応し得る。
【００５８】
【実施例】
以下実施例により本発明をさらに詳細に説明する。なお、実施例中の物性値は以下に述べる方法で測定した。
（１）ポリマーの固有粘度ＩＶ
オルソクロロフェノールを溶媒として２５℃で測定した。
（２）ポリマー中の金属含有量
蛍光Ｘ線により求めた。
（３）ＤＥＧ含有量
ポリマーをアルカリ分解した後、ガスクロマトグラフィーを用いて定量した。
（４）ポリマーの色調
スガ試験機（株）社製の色差計（ＳＭカラーコンピューター型式ＳＭ−３）を用いて、ハンター値として測定した。
（５）不溶性異物の有無
重合操作終了後のポリマー５ｇをガラス試験管に採取し、リメルトした後の溶融ポリマーを観察して、不溶性異物の有無を判定した。
【００５９】
○： 不溶性異物は認められない。
【００６０】
×： 不溶性異物がみられる。
【００６１】
参考例
以下に触媒の合成方法を記す。
【００６２】
触媒Ａ．クエン酸キレートチタン化合物の合成方法
撹拌機、凝縮器及び温度計を備えた３Ｌのフラスコ中に温水（３７１ｇ）にクエン酸・一水和物（５３２ｇ、２．５２モル）を溶解させた。この撹拌されている溶液に滴下漏斗からチタンテトライソプロポキシド（２８８ｇ、１．００モル）をゆっくり加えた。この混合物を１時間加熱、還流させて曇った溶液を生成させ、これよりイソプロパノール／水混合物を真空下で蒸留した。その生成物を７０℃より低い温度まで冷却し、そしてその撹拌されている溶液にＮａＯＨ（３８０ｇ、３．０４モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えた。得られた生成物をろ過し、次いでエチレングリコール（５０４ｇ、８０モル）と混合し、そして真空下で加熱してイソプロパノール／水を除去し、わずかに曇った淡黄色の生成物（Ｔｉ含有量３．８５重量％）を得た。
【００６３】
触媒Ｂ．クエン酸キレートチタン化合物（フェニルホスホン酸混合）の合成方法
撹拌機、凝縮器及び温度計を備えた３Ｌのフラスコ中に温水（３７１ｇ）にクエン酸・一水和物（５３２ｇ、２．５２モル）を溶解させた。この撹拌されている溶液に滴下漏斗からチタンテトライソプロポキシド（２８８ｇ、１．００モル）をゆっくり加えた。この混合物を１時間加熱、還流させて曇った溶液を生成させ、これよりイソプロパノール／水混合物を真空下で蒸留した。その生成物を７０℃より低い温度まで冷却し、そしてその撹拌されている溶液にＮａＯＨ（３８０ｇ、３．０４モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えた。得られた生成物をろ過し、次いでエチレングリコール（５０４ｇ、８０モル）と混合し、そして真空下で加熱してイソプロパノール／水を除去し、わずかに曇った淡黄色の生成物（Ｔｉ含有量３．８５重量％）を得た。この混合溶液に対し、フェニルホスホン酸（１５８ｇ、１．００モル）を加えることで、リン化合物を含有するチタン化合物を得た（Ｐ含有量２．４９重量％）。
【００６４】
触媒Ｃ．クエン酸キレートチタン化合物（フェニルホスホン酸、リン酸混合）の合成方法
撹拌機、凝縮器及び温度計を備えた３Ｌのフラスコ中に温水（３７１ｇ）にクエン酸・一水和物（５３２ｇ、２．５２モル）を溶解させた。この撹拌されている溶液に滴下漏斗からチタンテトライソプロポキシド（２８８ｇ、１．００モル）をゆっくり加えた。この混合物を１時間加熱、還流させて曇った溶液を生成させ、これよりイソプロパノール／水混合物を真空下で蒸留した。その生成物を７０℃より低い温度まで冷却し、そしてその撹拌されている溶液にＮａＯＨ（３８０ｇ、３．０４モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えた。得られた生成物をろ過し、次いでエチレングリコール（５０４ｇ、８０モル）と混合し、そして真空下で加熱してイソプロパノール／水を除去し、わずかに曇った淡黄色の生成物（Ｔｉ含有量３．８５重量％）を得た。この混合溶液に対し、フェニルホスホン酸（１５８ｇ、１．００モル）及びリン酸の８５重量／重量％水溶液（３９．９ｇ、０．３５モル）を加えることで、リン化合物を含有するチタン化合物を得た（Ｐ含有量３．３６重量％）。
【００６５】
触媒Ｄ．乳酸キレートチタン化合物の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（２１８ｇ、３．５１モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応混合物を１５分間撹拌し、そしてその反応フラスコに乳酸アンモニウム（２５２ｇ、２．００モル）の８５重量／重量％水溶液を加えると、透明な淡黄色の生成物（Ｔｉ含有量６．５４重量％）を得た。
【００６６】
触媒Ｅ．乳酸キレートチタン化合物（フェニルホスホン酸混合）の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（２１８ｇ、３．５１モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応混合物を１５分間撹拌し、そしてその反応フラスコに乳酸アンモニウム（２５２ｇ、２．００モル）の８５重量／重量％水溶液を加えると、透明な淡黄色の生成物（Ｔｉ含有量６．５４重量％）を得た。この混合溶液に対し、フェニルホスホン酸（１５８ｇ、１．００モル）を加えることで、リン化合物を含有するチタン化合物を得た（Ｐ含有量４．２３重量％）。
【００６７】
触媒Ｆ．乳酸キレートチタン化合物（フェニルホスホン酸、リン酸混合）の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（２１８ｇ、３．５１モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応混合物を１５分間撹拌し、そしてその反応フラスコに乳酸アンモニウム（２５２ｇ、２．００モル）の８５重量／重量％水溶液を加えると、透明な淡黄色の生成物（Ｔｉ含有量６．５４重量％）を得た。この混合溶液に対し、フェニルホスホン酸（１５８ｇ、１．００モル）及びリン酸の８５重量／重量％水溶液（３９．９ｇ、０．３５モル）を加えることで、リン化合物を含有するチタン化合物を得た（Ｐ含有量５．７１重量％）。
【００６８】
触媒Ｇ．チタンアルコキシド化合物の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（４９６ｇ、８．００モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応フラスコに、ＮａＯＨ（１２５ｇ、１．００モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えて透明な黄色の液体を得た（Ｔｉ含有量４．４４重量％）。
【００６９】
触媒Ｈ．チタンアルコキシド化合物（リン酸混合）の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（４９６ｇ、８．００モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応フラスコに、ＮａＯＨ（１２５ｇ、１．００モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えて透明な黄色の液体を得た（Ｔｉ含有量４．４４重量％）。この混合溶液に対し、リン酸の８５重量／重量％水溶液（１１４ｇ、１．００モル）を加えた（Ｐ含有量２．８７重量％）。
【００７０】
触媒Ｉ．チタンアルコキシド化合物（ジエチルホスホノ酢酸エチル混合）の合成方法
撹拌機、凝縮器及び温度計を備えた２Ｌのフラスコ中に撹拌されているチタンテトライソプロポキシド（２８５ｇ、１．００モル）に滴下漏斗からエチレングリコール（４９６ｇ、８．００モル）を加えた。添加速度は、反応熱がフラスコ内容物を約５０℃に加温するように調節された。その反応フラスコに、ＮａＯＨ（１２５ｇ、１．００モル）の３２重量／重量％水溶液を滴下漏斗によりゆっくり加えて透明な黄色の液体を得た（Ｔｉ含有量４．４４重量％）。この混合溶液に対し、ジエチルホスホノ酢酸エチル（２２４ｇ、１．００モル）を加えることで、リン化合物を含有するチタン化合物を得た（Ｐ含有量２．８７重量％）。
【００７１】
実施例１
予めビス（ヒドロキシエチル）テレフタレート約１２３ｋｇが仕込まれ、温度２５０℃、圧力１．２×１０^５Ｐａに保持されたエステル化反応槽に、ＥＡＨ（三洋化成社製 ２０重量％含有水溶液）とエチレングリコールとの混合液をポリマーに対してＥＡＨ成分として５０ｐｐｍ添加した後、高純度テレフタル酸（三井化学社製）１００ｋｇとエチレングリコール（日本触媒社製）４５ｋｇのスラリーを３時間かけて順次供給し、供給終了後もさらに１時間かけてエステル化反応を行った。このエステル化反応生成物の１２３ｋｇを重縮合槽に移送した。
【００７２】
引き続いて、エステル化反応生成物が移送された前記重縮合反応槽に、触媒Ａ（クエン酸キレートチタン化合物）の２重量％エチレングリコール溶液（ポリマーに対してチタン原子換算で１０ｐｐｍ）、ＥＡＨ（２０重量％含有水溶液）のエチレングリコール混合液（ポリマーに対してＥＡＨ成分として５０ｐｐｍ）、およびリン酸の２重量％エチレングリコール溶液（ポリマーに対してリン原子換算で５ｐｐｍ）を添加し、その後、低重合体を３０ｒｐｍで攪拌しながら、反応系を２５０℃から２８５℃まで徐々に昇温するとともに、圧力を４０Ｐａまで下げた。最終温度、最終圧力到達までの時間はともに６０分とした。所定の攪拌トルクとなった時点で反応系を窒素パージし常圧に戻し重縮合反応を停止し、冷水にストランド状に吐出、直ちにカッティングしてポリマーのペレットを得た。なお、減圧開始から所定の撹拌トルク到達までの時間は２時間５０分であった。
【００７３】
得られたポリマーのＩＶは０．６８であり、アルカリ化合物を添加していない比較例１に比べてポリマーのＤＥＧ量は０．９１ｗｔ％と少なく、特に色調ｂ値は良好であった。（なお、ポリマーから測定したチタン触媒由来のチタン原子の含有量は１０ｐｐｍ、リン原子の含有量は５ｐｐｍであり、Ｔｉ／Ｐ＝１．３であった。）
このポリエステルを乾燥後、紡糸基に供し、メルターにて溶融した後、計量し紡糸パック部から吐出し、２０００ｍ／分の速度で引取った。紡糸時に口金汚れの発生や糸切れはなく、紡糸性に優れていた。
実施例２〜９
実施例２〜９は、参考例での触媒Ｂ〜Ｉを使用し、いずれも２重量％エチレングリコール溶液（ポリマーに対してチタン原子換算で１０ｐｐｍ）を添加した以外は、実施例１と同様にして、エステル化、および重合した。なお、実施例４、および実施例７以外は、リン化合物を追加添加しなかった。
【００７４】
いずれも比較例１〜３に比べてＤＥＧ量は少なく、特に色調ｂ値は良好であった。
実施例１０〜１６
アルカリ化合物の種類、および量を変更する以外は、実施例１と同様にして、エステル化、および重合した。
【００７５】
いずれも比較例１〜３に比べてＤＥＧ量が少なく、特に色調ｂ値は良好であった。
実施例１７〜１９
ポリマーに対するチタン化合物の添加量、およびリン化合物の添加量を変更する以外は、実施例１と同様にして、エステル化、および重合した。
【００７６】
いずれも比較例１〜３に比べてＤＥＧ量は少なく、特に色調ｂ値は良好であった。
実施例２０
リン化合物の種類を変更した以外は、実施例１と同様にして、エステル化、および重合した。
【００７７】
比較例１〜３に比べてＤＥＧ量は少なく、特に色調ｂ値は良好であった。
実施例２１
予めエチレングリコールに、ＥＡＨを２０重量％含有する水溶液を添加、撹拌した混合溶液に、参考例において合成した触媒Ｂ（２重量％エチレングリコール溶液）を添加混合し、ＥＡＨ、水、エチレングリコールおよびチタンを含有する処理液を調整した。この処理液を重縮合前に添加（ポリマーに対してＥＡＨ成分として５０ｐｐｍ）した以外は、実施例１と同様にして、エステル化、および重合した。
【００７８】
比較例１〜３に比べてＤＥＧ量は少なく、特に色調ｂ値は良好であった。
実施例２２
予めエチレングリコールに、ＫＯＨを２重量％含有する水溶液を添加、撹拌した混合溶液に、参考例において合成した触媒Ｆ（２重量％エチレングリコール溶液）を添加混合し、ＫＯＨ、水、エチレングリコールおよびチタンを含有する処理液を調整した。この処理液を重縮合前に添加（ポリマーに対してＫＯＨとして５ｐｐｍ）した以外は、実施例１と同様にして、エステル化、および重合した。
【００７９】
比較例１〜３に比べてＤＥＧ量は少なく、特に色調ｂ値は良好であった。
比較例１〜３
参考例での触媒Ａ、ＥおよびＩを用いて、ＥＡＨを添加しない以外は実施例１と同様にして、エステル化、および重合した。
【００８０】
重合反応性は良好であったが、実施例に比べてＤＥＧ量が多く、ポリマーの色調も特にｂ値が高く、黄味を帯びたものであった。
比較例４
アルカリ化合物としてトリエチルアミン（１００ｐｐｍ添加）を用いる以外は、
実施例１と同様にして、エステル化、および重合した。
【００８１】
重合反応性はやや良好であったものの、実施例に比べてＤＥＧ量が多く、ポリマーの色調ｂ値が高く、黄味を帯びたものであった。
比較例５
触媒に三酸化アンチモン（住友金属鉱山社製）を、得られるポリマーに対してアンチモン原子換算で３５０ｐｐｍ添加したこと以外は実施例１と同様にして、エステル化、および重合し、得られたポリマーを用いて紡糸を行った。
【００８２】
各実施例に比べて重合反応性は劣っていた。また、得られるポリマーの色調ｂ値は良好であったものの、ＤＥＧ量が多く、紡糸時に口金汚れが発生し、糸切れがあり、操業性に劣っていた。
【００８３】
【表１】

【００８４】
【表２】

【００８５】
【発明の効果】
本発明のポリエステルの製造方法によって、エステル化反応性および／又は重縮合反応性に優れると共に、色調が良好であり、ＤＥＧ含有量が少なく、かつ、紡糸性の良好なポリエステルを得ることができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a polyester having excellent polymer properties such as color tone and a polyester having excellent transesterification and / or polycondensation reactivity.
[0002]
[Prior art]
Generally, polyethylene terephthalate is produced from terephthalic acid or its ester-forming derivative and ethylene glycol, but in commercial processes for producing high molecular weight polymers, antimony compounds are widely used as polycondensation catalysts. However, polymers containing antimony compounds have some undesirable properties, as described below.
[0003]
For example, when a polymer obtained by using an antimony catalyst is melt-spun into fibers, it is known that residues of the antimony catalyst accumulate around the die hole. If the deposition progresses, it causes a defect in the filament, so that it is necessary to remove the filament in a timely manner. It is believed that the deposition of the antimony catalyst residue occurs because the antimony compound in the polymer is denatured in the vicinity of the die, a part of which evaporates and dissipates, and then a component mainly composed of antimony remains in the die.
[0004]
Also, the antimony catalyst residue in the polymer tends to be relatively large particles, and becomes a foreign substance, which causes an increase in the filter pressure of the filter during molding, breakage of the yarn during spinning, or breakage of the film during film formation. It has unfavorable characteristics, and is one of the causes of lowering operability.
[0005]
In view of the above background, polyesters having a low or no antimony content have been demanded. Therefore, when a role of the polycondensation catalyst is required for a compound other than the antimony-based compound, a germanium compound is known, but the germanium compound is very expensive and is difficult to be used for general purposes.
[0006]
As a polycondensation catalyst other than an antimony compound or a germanium compound, a titanium compound is conventionally known.However, when such a titanium compound is used, the obtained polyester tends to be yellowish, The color tone becomes deep yellow when an amount sufficient to obtain industrial productivity is used. As an attempt to overcome the problems when using a titanium compound as a catalyst in this way, a method of using a specific phosphorus compound in combination or a method of adding an alkylamine, or using a homogeneous solution composed of a mixture with an organic carboxylic acid is used. Methods and the like have been proposed (see Patent Documents 1 to 3). Further, a method of using a titanium compound such as a titanium complex comprising a titanium compound and a phosphorus compound as a catalyst for polyester polymerization has been proposed (see Patent Documents 4 to 6). According to these methods, although foreign substances due to the catalyst can be reduced, the polycondensation reaction is delayed, and the side reaction is accelerated, so that the amount of DEG increases, Further improvement is desired, for example, the color tone is not at a satisfactory level.
[0007]
[Patent Document 1]
JP-A-52-136294
[Patent Document 2]
JP-A-55-56121
[Patent Document 3]
JP-A-56-129220
[Patent Document 4]
JP 2001-524536 A
[Patent Document 5]
JP-A-2002-512267
[Patent Document 6]
JP-A-2002-293909
[Problems to be solved by the invention]
An object of the present invention is to overcome the above-mentioned conventional problems and to produce a polyester having excellent esterification reactivity and / or polycondensation reactivity, good color tone, low DEG content, and good spinnability. It is to provide a method.
[0014]
[Means for Solving the Problems]
In order to solve the above problems, an object of the present invention is to provide a method for producing a polyester by polycondensing a product obtained by an esterification reaction of terephthalic acid and ethylene glycol as a main component, wherein the esterification and / or polycondensation is carried out. As the catalyst, a titanium compound whose substituent has at least one group selected from the group consisting of functional groups represented by the following general formulas 1 to 6, and a quaternary ammonium compound, potassium hydroxide, And sodium hydroxide, at least one alkali compound selected from the group consisting of sodium hydroxide and sodium hydroxide.
[0015]
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[0016]
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[0017]
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[0018]
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[0019]
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[0020]
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[0021]
(In Formulas 1 to 6, R _{1 to} R ₃ each independently have hydrogen, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group, a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, an ester group, or an amino group. Represents a hydrocarbon group having 1 to 30 carbon atoms.)
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
The polyester of the present invention comprises terephthalic acid, which is an aromatic dicarboxylic acid, and a diol containing ethylene glycol as a main component.
[0023]
In the polyester of the present invention, adipic acid, isophthalic acid, sebacic acid, phthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, dicarboxylic acids such as cyclohexanedicarboxylic acid, and the like to form an ester thereof other than diethylene glycol as a copolymerization component. Dioxy compounds such as polyethylene glycol, hexamethylene glycol, neopentyl glycol, polypropylene glycol, and cyclohexane dimethanol; oxycarboxylic acids such as p- (β-oxyethoxy) benzoic acid; and ester-forming derivatives thereof. It may be.
[0024]
The titanium compound as a polymerization catalyst in the present invention needs to be a titanium compound whose substituent is at least one selected from the group consisting of functional groups represented by the following general formulas 1 to 6.
[0025]
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[0026]
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[0027]
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[0028]
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[0029]
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[0030]
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[0031]
(In Formulas 1 to 6, R _{1 to} R ₃ each independently have hydrogen, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group, a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, an ester group, or an amino group. Represents a hydrocarbon group having 1 to 30 carbon atoms.)
Formula 1 of the present invention includes an alkoxy group such as ethoxide, propoxide, isopropoxide, butoxide, and 2-ethylhexoxide, and a hydroxy polycarboxylic acid compound such as lactic acid, malic acid, tartaric acid, and citric acid. Functional groups. Formula 2 includes a functional group consisting of a β-diketone compound such as acetylacetone and a ketoester compound such as methyl acetoacetate and ethyl acetoacetate.
[0032]
Formula 3 includes a functional group composed of phenoxy, cresylate, salicylic acid, and the like.
[0033]
Formula 4 includes lactate, an acylate group such as stearate, phthalic acid, trimellitic acid, trimesic acid, hemmellitic acid, pyromellitic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, Maleic acid, fumaric acid, polycarboxylic acid compounds such as cyclohexanedicarboxylic acid or anhydrides thereof, ethylenediaminetetraacetic acid, nitrilotripropionic acid, carboximinodiacetic acid, carboxymethyliminodipropionic acid, diethylenetriaminopentaacetic acid, triethylenetriaminopentaacetic acid, triethylene Examples of the functional group include a nitrogen-containing polyvalent carboxylic acid such as ethylene tetramino hexaacetic acid, iminodiacetic acid, iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, and methoxyethyliminodiacetic acid.
[0034]
Formula 5 includes a functional group composed of aniline, phenylamine, diphenylamine, and the like. Preferred examples thereof include diisopropoxybisacetylacetone and triethanolaminate isopropoxide containing two of these substituents.
[0035]
Above all, it is preferable that Formula 1 and / or Formula 4 are included from the viewpoint of the thermal stability and color tone of the polymer.
[0036]
Examples of the titanium compound include titanium diisopropoxybisacetylacetonate and titanium triethanolaminate isopropoxide containing two or more of these substituents of formulas 1 to 6.
[0037]
When the titanium compound as a catalyst in the present invention is added in an amount of 0.5 to 150 ppm in terms of titanium atom with respect to the obtained polymer, the esterification reaction and polymerization activity are high, and the obtained polymer has good melting heat resistance and color tone, and thus is preferable. More preferably, it is 1 to 100 ppm, still more preferably 3 to 50 ppm.
[0038]
The titanium compound as the catalyst of the present invention may be added as it is to the reaction system of the polyester, but the compound is mixed in advance with a solvent containing a diol component forming a polyester such as ethylene glycol to form a solution or slurry. It is preferable to remove the low-boiling components such as alcohol used in the synthesis of the compound and then add the mixture to the reaction system, since the formation of foreign substances in the polymer is further suppressed. As for the timing of the addition, as the esterification reaction catalyst, there are a method of adding the catalyst immediately after the addition of the raw material and a method of adding the catalyst together with the raw material. In addition, when added as a polycondensation reaction catalyst, it may be substantially before the start of the polycondensation reaction, and may be added before the esterification reaction or after the end of the reaction and before the start of the polycondensation reaction catalyst. Is also good.
[0039]
The catalyst of the present invention refers to a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof in the following reactions (1) and (2) in all or part of the elementary reactions Refers to a compound that substantially contributes to the promotion of the reaction.
(1) Esterification reaction, which is a reaction between a dicarboxylic acid component and a diol component (2) Polycondensation in which the esterification reaction is substantially completed and the resulting polyethylene terephthalate low polymer is made to have a high degree of polymerization by a dedioling reaction. Reaction The alkali compound of the present invention needs to be at least one alkali compound selected from the group consisting of quaternary ammonium compounds, potassium hydroxide and sodium hydroxide.
[0040]
In the present invention, among the at least one alkali compound selected from the group consisting of these quaternary ammonium compounds, potassium hydroxide and sodium hydroxide, when a quaternary ammonium compound is used, the color tone of the obtained polyester is particularly good. It is preferable because it is a compound that volatilizes at a temperature of 280 ° C. or lower, so that the residual amount in the finally obtained polyester is reduced and no foreign matter is contained in the polymer.
[0041]
Preferred quaternary ammonium compounds of the present invention include, for example, compounds represented by the following formula 7.
[0042]
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[0043]
(However, in Formula 7, R ₁ , R ₂ , R ₃ and R ₄ represent a group selected from a hydrogen atom, an alkyl group, an aryl group, and an allyl group.)
More specifically, examples of the compound of the formula 7 include tetramethylammonium hydroxide, tetraethylammonium hydroxide (hereinafter referred to as EAH), tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, and the like. be able to.
[0044]
In the case of a quaternary ammonium compound, the amount of the alkali compound of the present invention is preferably 10 to 3000 ppm based on the obtained polyester. When the content is 10 ppm or more, the effect of improving the color tone of the polymer and suppressing the increase in the amount of DEG due to the suppression of side reactions during the polymerization reaction is sufficiently exhibited. On the other hand, especially when the content is 3000 ppm or less, the color tone of the polymer is good. The addition amount is more preferably from 20 to 2000 ppm, and still more preferably from 50 to 1000 ppm. In the case of sodium hydroxide or potassium hydroxide, the content is preferably 0.1 to 100 ppm. When the amount is 0.1 ppm or more, the effect of improving the color tone of the polymer and suppressing the increase in the amount of DEG due to the suppression of side reactions during the polymerization reaction is sufficiently exhibited. On the other hand, when the content is 100 ppm or less, there is no delay in the esterification reaction or the polycondensation reaction, which is favorable. The addition amount is more preferably from 0.5 to 50 ppm, further preferably from 1 to 20 ppm.
[0045]
The addition time of the alkali compound in the present invention is, for example, before the start of the esterification reaction, during the esterification reaction, after the esterification reaction, and / or before the start of the polycondensation, but is not particularly limited. May be added in portions before polycondensation. It is preferable to add the titanium compound before or simultaneously with the addition of the titanium compound from the viewpoint of the color tone of the obtained polymer and the effect of suppressing the amount of DEG.
[0046]
Further, the titanium compound used in the present invention is treated in advance with water containing an alkali compound, an organic solvent, or a mixture of water and an organic solvent, and when the resulting treatment liquid is added, the titanium compound is uniformly dispersed or dissolved. This is preferable because generation of foreign matter in the polymer is suppressed. Further, when the treatment liquid containing the titanium compound is an aqueous solution, after dilution with a diol component forming a polyester such as ethylene glycol, and then added to the reaction system, local concentration due to a rapid temperature change hardly occurs. Therefore, no insoluble foreign matter is generated, which is preferable.
[0047]
In the case where the titanium compound is previously treated with water containing an alkali compound in advance, an organic solvent, or a mixture of water and an organic solvent, water, an organic solvent, or a mixture of water and an organic solvent is treated with an alkali compound. Is preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight, because the titanium compound to be added thereafter is more easily dispersed or dissolved.
[0048]
When the titanium compound of the present invention is used as a catalyst which has been reacted with a phosphorus compound in advance, (1) the titanium compound is mixed with a solvent and part or all of the titanium compound is dissolved in the solvent. Dissolve and dilute in stock solution or solvent and add dropwise. (2) When using a ligand of a titanium compound such as the hydroxycarboxylic acid-based compound or the polyvalent carboxylic acid-based compound, the titanium compound or the ligand compound is mixed with a solvent, and part or all of the mixture is dissolved in the solvent. And the ligand compound or titanium compound is dissolved and diluted in a stock solution or a solvent and added dropwise to this mixed solution. Further, it is preferable to further dissolve and dilute the phosphorus compound in a stock solution or a solvent and then add the phosphorus compound to the mixed solution, from the viewpoint of improving thermal stability and color tone. The above reaction conditions are carried out by heating at a temperature of 0 to 200 ° C for 1 minute or more, preferably at a temperature of 20 to 100 ° C for 2 to 100 minutes. The reaction pressure at this time is not particularly limited, and may be normal pressure. Further, the solvent can be selected from those capable of dissolving a part or all of the titanium compound, the phosphorus compound and the carbonyl group-containing compound, but is preferably water, methanol, ethanol, ethylene glycol, propanediol, It is selected from butanediol, benzene, and xylene.
[0049]
Further, from the viewpoint of the thermal stability and color tone of the polyester at the time of spinning, the polyester of the present invention, before the start of polymerization, so that phosphorus is contained in the polyester along with the titanium compound in an amount of 0.1 to 400 ppm in terms of phosphorus atoms, or It may be added at an earlier stage. Such a phosphorus compound is any one or two of phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, phosphine oxide, phosphonous acid, phosphinous acid, and phosphine. Is preferred. Specifically, for example, phosphoric acids, such as phosphoric acid, trimethyl phosphate, triethyl phosphate, and triphenyl phosphate, and phosphorous acids, such as phosphorous acid, trimethyl phosphite, triethyl phosphite, and triphenyl phosphite. Phosphoric acid, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid, butylphosphonic acid, phenylphosphonic acid and the like are preferably used. The phosphorus content is preferably from 1 to 200 ppm, more preferably from 3 to 100 ppm.
[0050]
In addition, it is preferable that Ti / P = 0.1 to 20 in terms of a molar ratio of a phosphorus atom to a titanium atom of the titanium compound because the polyester has good thermal stability and color tone. More preferably, Ti / P is 0.2 to 10, and further preferably, Ti / P is 0.3 to 5.
[0051]
In the polyester of the present invention, the content of the antimony compound needs to be 50 ppm or less in terms of metal atoms. By setting the content in this range, it is possible to obtain a relatively inexpensive polymer with less occurrence of die contamination during molding and the like. More preferably, it is preferably not more than 20 ppm, particularly not substantially contained.
[0052]
In addition, conventionally known pigments such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin, and carbon black, as well as conventionally known additives such as coloring inhibitors, stabilizers, and antioxidants. It may be contained.
[0053]
The polyester of the present invention can be obtained by the following method.
[0054]
For example, using terephthalic acid and ethylene glycol as raw materials, a low polymer is obtained by a direct esterification reaction, and a high molecular weight polymer is produced by a subsequent polycondensation reaction.
[0055]
Here, the titanium compound of the present invention is used as a catalyst for esterification and / or polycondensation, and at least one alkali compound selected from the group consisting of a quaternary ammonium compound, potassium hydroxide, and sodium hydroxide May be added, and the reaction may be carried out using a small amount of an antimony compound, a tin compound, a germanium compound, or a compound such as manganese, cobalt, or zinc as a catalyst. The esterification reaction proceeds without a catalyst, but the titanium compound of the present invention may be added as a catalyst.
[0056]
The production method of the present invention is an optional step in the series of reactions, preferably to the low polymer obtained in the first half of the series of reactions, after adding additives such as titanium oxide particles and a cobalt compound as a matting agent. Alternatively, the titanium compound of the present invention may be added as a polycondensation catalyst to carry out a polycondensation reaction to obtain a high molecular weight polyethylene terephthalate.
[0057]
The above reaction is carried out in a batch system, a semi-batch system, a continuous system, or the like, but the production method of the present invention can be applied to any of these systems.
[0058]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples. The physical properties in the examples were measured by the methods described below.
(1) Intrinsic viscosity IV of polymer
The measurement was performed at 25 ° C. using orthochlorophenol as a solvent.
(2) Metal content in polymer Determined by fluorescent X-ray.
(3) DEG content After the polymer was alkali-decomposed, it was quantified using gas chromatography.
(4) Color tone of polymer Measured as a Hunter value using a color difference meter (SM Color Computer Model SM-3) manufactured by Suga Test Instruments Co., Ltd.
(5) Presence or absence of insoluble foreign matter 5 g of the polymer after completion of the polymerization operation was collected in a glass test tube, and the molten polymer after remelting was observed to determine the presence or absence of insoluble foreign matter.
[0059]
：: No insoluble foreign matter was observed.
[0060]
×: Insoluble foreign matter is observed.
[0061]
Reference Example A method for synthesizing a catalyst is described below.
[0062]
Catalyst A. Synthesis Method of Citric Acid Chelate Titanium Compound Citric acid monohydrate (532 g, 2.52 mol) was dissolved in warm water (371 g) in a 3 L flask equipped with a stirrer, condenser and thermometer. Titanium tetraisopropoxide (288 g, 1.00 mol) was slowly added to the stirred solution from a dropping funnel. The mixture was heated at reflux for 1 hour to form a cloudy solution from which the isopropanol / water mixture was distilled under vacuum. The product was cooled to below 70 ° C., and to the stirring solution was slowly added a 32% w / w aqueous solution of NaOH (380 g, 3.04 mol) via dropping funnel. The product obtained is filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under vacuum to remove the isopropanol / water and give a slightly cloudy pale yellow product (Ti content 3 .85% by weight).
[0063]
Catalyst B. Synthesis method of citric acid chelate titanium compound (phenylphosphonic acid mixture) Citric acid monohydrate (532 g, 2.52 mol) in warm water (371 g) in a 3 L flask equipped with stirrer, condenser and thermometer Was dissolved. Titanium tetraisopropoxide (288 g, 1.00 mol) was slowly added to the stirred solution from a dropping funnel. The mixture was heated at reflux for 1 hour to form a cloudy solution from which the isopropanol / water mixture was distilled under vacuum. The product was cooled to below 70 ° C., and to the stirring solution was slowly added a 32% w / w aqueous solution of NaOH (380 g, 3.04 mol) via dropping funnel. The product obtained is filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under vacuum to remove the isopropanol / water and give a slightly cloudy pale yellow product (Ti content 3 .85% by weight). Phenylphosphonic acid (158 g, 1.00 mol) was added to the mixed solution to obtain a titanium compound containing a phosphorus compound (P content: 2.49% by weight).
[0064]
Catalyst C. Synthesis method of citric acid chelate titanium compound (mixture of phenylphosphonic acid and phosphoric acid) In a 3 L flask equipped with a stirrer, a condenser and a thermometer, warm water (371 g) and citric acid monohydrate (532 g, 2. 52 mol) were dissolved. Titanium tetraisopropoxide (288 g, 1.00 mol) was slowly added to the stirred solution from a dropping funnel. The mixture was heated at reflux for 1 hour to form a cloudy solution from which the isopropanol / water mixture was distilled under vacuum. The product was cooled to below 70 ° C., and to the stirring solution was slowly added a 32% w / w aqueous solution of NaOH (380 g, 3.04 mol) via dropping funnel. The product obtained is filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under vacuum to remove the isopropanol / water and give a slightly cloudy pale yellow product (Ti content 3 .85% by weight). By adding phenylphosphonic acid (158 g, 1.00 mol) and an 85% w / w aqueous solution of phosphoric acid (39.9 g, 0.35 mol) to the mixed solution, the titanium compound containing the phosphorus compound was added. Was obtained (P content: 3.36% by weight).
[0065]
Catalyst D. Synthesis method of titanium lactate chelate compound Titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, a condenser and a thermometer was added with ethylene glycol (218 g, 3 .51 mol). The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. The reaction mixture was stirred for 15 minutes, and an 85% w / w aqueous solution of ammonium lactate (252 g, 2.00 mol) was added to the reaction flask to give a clear, pale yellow product (Ti content 6.54%). %).
[0066]
Catalyst E. Method for synthesizing titanium lactate chelate compound (phenylphosphonic acid mixture) Titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, condenser and thermometer from a dropping funnel. Ethylene glycol (218 g, 3.51 mol) was added. The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. The reaction mixture was stirred for 15 minutes, and an 85% w / w aqueous solution of ammonium lactate (252 g, 2.00 mol) was added to the reaction flask to give a clear, pale yellow product (Ti content 6.54%). %). Phenylphosphonic acid (158 g, 1.00 mol) was added to the mixed solution to obtain a phosphorus compound-containing titanium compound (P content: 4.23% by weight).
[0067]
Catalyst F. Synthesis method of titanium lactate chelate compound (phenylphosphonic acid, phosphoric acid mixture) Titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, condenser and thermometer Ethylene glycol (218 g, 3.51 mol) was added from the dropping funnel. The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. The reaction mixture was stirred for 15 minutes, and an 85% w / w aqueous solution of ammonium lactate (252 g, 2.00 mol) was added to the reaction flask to give a clear, pale yellow product (Ti content 6.54%). %). By adding phenylphosphonic acid (158 g, 1.00 mol) and an 85% w / w aqueous solution of phosphoric acid (39.9 g, 0.35 mol) to the mixed solution, the titanium compound containing the phosphorus compound was added. Was obtained (P content: 5.71% by weight).
[0068]
Catalyst G. Synthesis method of titanium alkoxide compound Titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, a condenser and a thermometer was added with ethylene glycol (496 g, 8.8 g) from a dropping funnel. 00 mol) was added. The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. A 32% w / w aqueous solution of NaOH (125 g, 1.00 mol) was slowly added to the reaction flask via a dropping funnel to give a clear yellow liquid (Ti content 4.44% w / w).
[0069]
Catalyst H. Synthesis method of titanium alkoxide compound (mixed phosphoric acid) Titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, a condenser and a thermometer was added with ethylene glycol through a dropping funnel. (496 g, 8.00 mol) was added. The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. A 32% w / w aqueous solution of NaOH (125 g, 1.00 mol) was slowly added to the reaction flask via a dropping funnel to give a clear yellow liquid (Ti content 4.44% w / w). To this mixed solution was added a 85% by weight / weight aqueous solution of phosphoric acid (114 g, 1.00 mol) (P content: 2.87% by weight).
[0070]
Catalyst I. Synthesis method of titanium alkoxide compound (ethyl diethylphosphonoacetate mixture) Dropping funnel into titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, a condenser and a thermometer. Of ethylene glycol (496 g, 8.00 mol). The rate of addition was adjusted so that the heat of reaction warmed the contents of the flask to about 50 ° C. A 32% w / w aqueous solution of NaOH (125 g, 1.00 mol) was slowly added to the reaction flask via a dropping funnel to give a clear yellow liquid (Ti content 4.44% w / w). Ethyl diethyl phosphonoacetate (224 g, 1.00 mol) was added to the mixed solution to obtain a titanium compound containing a phosphorus compound (P content: 2.87% by weight).
[0071]
Example 1
Pre-bis (hydroxyethyl) terephthalate about 123kg is charged, temperature 250 ° C., the esterification reaction vessel held at a pressure 1.2 × ¹⁰ 5 Pa, EAH (manufactured by Sanyo Chemical Industries, Ltd. 20 wt% aqueous solution containing) and ethylene glycol And a slurry of 100 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals, Inc.) and 45 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) are successively supplied over 3 hours, and then supplied. After the completion, the esterification reaction was further performed for 1 hour. 123 kg of this esterification reaction product was transferred to a polycondensation tank.
[0072]
Subsequently, a 2% by weight ethylene glycol solution (10 ppm in terms of titanium atom with respect to the polymer) of catalyst A (titanium citrate compound) and EAH (20%) were placed in the polycondensation reaction tank in which the esterification reaction product was transferred. Then, a mixed solution of ethylene glycol (50% by weight as an EAH component with respect to the polymer) and a 2% by weight ethylene glycol solution of phosphoric acid (5 ppm in terms of phosphorus atom with respect to the polymer) were added. While stirring the combined liquid at 30 rpm, the temperature of the reaction system was gradually increased from 250 ° C. to 285 ° C., and the pressure was reduced to 40 Pa. The time required to reach the final temperature and the final pressure was 60 minutes. When the stirring torque reached a predetermined value, the reaction system was purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged into cold water in a strand form, and immediately cut to obtain polymer pellets. The time from the start of the pressure reduction to the arrival of the predetermined stirring torque was 2 hours and 50 minutes.
[0073]
The IV of the obtained polymer was 0.68, and the DEG amount of the polymer was as small as 0.91 wt% as compared with Comparative Example 1 in which no alkali compound was added, and the color b value was particularly good. (The content of titanium atoms derived from the titanium catalyst measured from the polymer was 10 ppm, the content of phosphorus atoms was 5 ppm, and Ti / P was 1.3.)
After drying, the polyester was supplied to a spinning base, melted by a melter, weighed, discharged from a spin pack, and taken up at a speed of 2000 m / min. There was no spinneret stain or yarn breakage during spinning, and the spinning properties were excellent.
Examples 2 to 9
Examples 2 to 9 were performed in the same manner as in Example 1 except that the catalysts B to I of the reference example were used, and a 2% by weight ethylene glycol solution (10 ppm in terms of titanium atom with respect to the polymer) was added. Was esterified and polymerized. Except for Examples 4 and 7, no additional phosphorus compound was added.
[0074]
In each case, the DEG amount was smaller than in Comparative Examples 1 to 3, and the color tone b value was particularly good.
Examples 10 to 16
Esterification and polymerization were carried out in the same manner as in Example 1 except that the kind and amount of the alkali compound were changed.
[0075]
In each case, the amount of DEG was smaller than in Comparative Examples 1 to 3, and the color tone b value was particularly good.
Examples 17 to 19
Esterification and polymerization were carried out in the same manner as in Example 1 except that the addition amount of the titanium compound and the addition amount of the phosphorus compound to the polymer were changed.
[0076]
In each case, the DEG amount was smaller than in Comparative Examples 1 to 3, and the color tone b value was particularly good.
Example 20
Esterification and polymerization were carried out in the same manner as in Example 1 except that the type of the phosphorus compound was changed.
[0077]
The amount of DEG was smaller than that of Comparative Examples 1 to 3, and the color tone b value was particularly good.
Example 21
An aqueous solution containing 20% by weight of EAH was added to ethylene glycol in advance, and a catalyst B (2% by weight ethylene glycol solution) synthesized in Reference Example was added to the stirred mixed solution, followed by mixing with EAH, water, ethylene glycol and titanium. Was prepared. Esterification and polymerization were carried out in the same manner as in Example 1 except that this treatment liquid was added before the polycondensation (50 ppm as an EAH component relative to the polymer).
[0078]
The DEG amount was smaller than in Comparative Examples 1 to 3, and the color tone b value was particularly good.
Example 22
An aqueous solution containing 2% by weight of KOH was added to ethylene glycol in advance, and the catalyst F (2% by weight ethylene glycol solution) synthesized in Reference Example was added and mixed to the stirred mixed solution to obtain KOH, water, ethylene glycol and titanium. Was prepared. Esterification and polymerization were carried out in the same manner as in Example 1, except that this treatment liquid was added before the polycondensation (5 ppm as KOH with respect to the polymer).
[0079]
The DEG amount was smaller than in Comparative Examples 1 to 3, and the color tone b value was particularly good.
Comparative Examples 1-3
Using catalysts A, E and I in the reference example, esterification and polymerization were carried out in the same manner as in Example 1 except that EAH was not added.
[0080]
Although the polymerization reactivity was good, the amount of DEG was larger than that of the examples, and the color tone of the polymer was particularly high in b value and yellowish.
Comparative Example 4
Except for using triethylamine (100 ppm added) as an alkali compound,
Esterification and polymerization were carried out in the same manner as in Example 1.
[0081]
Although the polymerization reactivity was somewhat good, the amount of DEG was larger than in the examples, the color tone b value of the polymer was high, and the polymer was yellowish.
Comparative Example 5
Esterification and polymerization were carried out in the same manner as in Example 1 except that antimony trioxide (manufactured by Sumitomo Metal Mining Co., Ltd.) was added to the resulting polymer in an amount of 350 ppm in terms of antimony atoms. And spinning was performed.
[0082]
Polymerization reactivity was inferior to each example. Further, although the obtained polymer had a good color tone b value, it had a large amount of DEG, stains were generated during spinning, yarn breakage occurred, and the operability was poor.
[0083]
[Table 1]

[0084]
[Table 2]

[0085]
【The invention's effect】
According to the polyester production method of the present invention, a polyester having excellent esterification reactivity and / or polycondensation reactivity, good color tone, low DEG content, and good spinnability can be obtained.

Claims (10)

In a method for producing a polyester by polycondensing a product obtained by an esterification reaction of terephthalic acid and ethylene glycol as a main component, a substituent is used as a catalyst for esterification and / or polycondensation, wherein the substituent has the following general formula 1 A titanium compound having at least one group selected from the group consisting of functional groups represented by 6 is used, and at least one selected from the group consisting of quaternary ammonium compounds, potassium hydroxide, and sodium hydroxide A method for producing a polyester, comprising adding a kind of alkali compound.

(In Formulas 1 to 6, R _{1 to} R ₃ each independently have hydrogen, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group, a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, an ester group, or an amino group. Represents a hydrocarbon group having 1 to 30 carbon atoms.) The method for producing a polyester according to claim 1, wherein R _{1 to} R _{3 in} Formulas 1 to ₃ are each independently hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. In Formulas 1 to 3, at least one of R _{1 to} R ₃ is a hydrocarbon group having 1 to 30 carbon atoms having a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, or an ester group. Item 10. A method for producing a polyester according to Item 1. The method for producing a polyester according to claim ₃ , wherein at least one of R _{1 to} R _{3 in} Formula 1 is a hydrocarbon group having a carboxyl group or an ester group and having 1 to 30 carbon atoms. R _{1 in the} formula 4 is a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon group having 1 to 30 carbon atoms having a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group or an ester group. 2. The method for producing the polyester according to 1. The method for producing a polyester according to any one of claims 1 to 5, wherein 0.5 to 150 ppm in terms of titanium atoms is added to the obtained polyester. The alkali compound is added to the obtained polyester in an amount of 10 to 3000 ppm in the case of a quaternary ammonium compound, and 0.1 to 100 ppm in the case of sodium hydroxide or potassium hydroxide. The method for producing a polyester according to any one of the above. The method for producing a polyester according to any one of claims 1 to 7, wherein the phosphorus compound is added as a phosphorus atom in the polyester production step so as to be 0.1 to 400 ppm or less based on the polyester. The method for producing a polyester according to any one of claims 1 to 8, wherein the ratio of the titanium compound to the phosphorus compound is Ti / P = 0.1 to 20 as a molar ratio of titanium atom to phosphorus atom. . A titanium compound whose substituent is at least one selected from the group consisting of functional groups represented by the following general formulas 1 to 6 is treated with water containing an alkali compound, an organic solvent, or a mixture of water and an organic solvent. The method for producing a polyester according to any one of claims 1 to 9, wherein the obtained treatment liquid is added.

(In Formulas 1 to 6, R _{1 to} R ₃ each independently have hydrogen, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group, a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, an ester group, or an amino group. Represents a hydrocarbon group having 1 to 30 carbon atoms.)