JP3696222B2 - Dispersion - Google Patents

Description

【０００９】
本発明の第２は、分散剤において、２個以上のヒドロキシル基を有するモノカルボン酸と、一般式（１）で表されるラクトン化合物のモル比が１：５０〜１：１であることを特徴とする本発明の第１記載の分散液を提供する。
本発明の第３は、分散剤において、分岐構造含有カルボキシル基末端ポリラクトン化合物とポリアミン化合物の反応物が、塩、アミド、または、それらの混合物であることを特徴とする本発明の第１または２記載の分散液を提供する。
本発明の第４は、分散剤において、分岐構造含有カルボキシル基末端ポリラクトン化合物の数平均分子量が１００〜５０００であることを特徴とする本発明の第１〜３のいずれか１項記載の分散液を提供する。
本発明の第５は、分散剤において、ポリアミン化合物の数平均分子量が１００から２００００であることを特徴とする本発明の第１〜４のいずれか１項記載の分散液を提供する。
本発明の第６は、分散剤において、ポリアミン化合物がポリエチレンイミンであることを特徴とする本発明の第１〜５のいずれか１項記載の分散液を提供する。
本発明の第７は、分散剤において、ラクトン化合物がε−カプロラクトンであることを特徴とする本発明の第１〜６のいずれか１項記載の分散液を提供する。
本発明の第８は、微細な固体が顔料である本発明の第１〜７のいずれか１項に記載の分散液を提供する。
本発明の第９は、塗料用である本発明の第１〜８のいずれか１項に記載の分散液を提供する。
本発明の第１０は、印刷インキ用である本発明の第１〜８のいずれか１項に記載の分散液を提供する。
【００１０】
【発明の実施の形態】
分岐構造含有カルボキシル基末端ポリラクトン化合物（以下、単にポリラクトン化合物ともいう）は、２個以上のヒドロキシル基を有するモノカルボン酸（以下、単にヒドロキシカルボン酸ともいう）を開始剤あるいは共重合成分として一般式（１）で表されるラクトン化合物を開環重合させて得られる。
【００１１】
ここで使用することのできるヒドロキシカルボン酸としては、ヒドロキシル基を２個以上有していればよく、脂肪族、芳香族、および不飽和のヒドロキシカルボン酸を使用することができる。例としては ２，２−ジメチロールプロピオン酸、２，２−ジメチロール酪酸、２，２−ジメチロール吉草酸、２，２−ジメチロールペンタン酸、ジヒドロキシ安息香酸、４−ヒドロキシイソフタル酸、酒石酸、グルコン酸、４，４−ビス（ヒドロキシフェニル）酪酸、４，４−ビス（ヒドロキシフェニル）吉草酸等を使用できる。
【００１２】
ラクトン化合物としては、ε−カプロラクトン、δ−バレロラクトン、β−メチル−δ−バレロラクトン、β−プロピオラクトン、γ−ブチロラクトン、２−メチルカプロラクトン、４−メチルカプロラクトン等、一般式（１）で表されるラクトン類を使用することができる。これらは、単独でまたは混合して用いてよい。一般式（１）において、メチル基の数は０から直鎖アルキレン基の炭素数の２倍までの任意の数であり、好ましくは１〜３である。また、直鎖アルキレン基（側鎖のメチル基を除く）の炭素数は好ましくは２〜５である。
【００１３】
２個以上のヒドロキシル基を有するヒドロキシカルボン酸とラクトン化合物を共重合させて得られる分岐構造を有するポリラクトン化合物（分岐構造含有カルボキシル基末端ポリラクトン化合物、または単にポリラクトン化合物ともいう）の数平均分子量は、通常、１００から５０００の範囲であり、好ましくは５００から３０００の範囲である。ポリラクトン化合物の分子量が１００未満では、顔料の回りに十分な立体反発層を形成することができず、また、分子量が５０００を超えると分散剤全体の分子量が大きくなりすぎ、塗料またはインキ用ビヒクルとの相溶性が低下し、また顔料分散性も低下するので好ましくない。
【００１４】
ポリラクトン化合物中の分岐度は好ましくは平均で３以上である。これ未満では、直鎖状のポリラクトン鎖と比較して立体反発層の増大効果がなく、製造された分散剤も結晶性が高くなる傾向がある。また、平均の分岐度が２０を超えると分散剤の水酸基含有量が高くなりすぎ、トルエン、キシレン等の非極性の溶剤に溶解しにくくなるので好ましくない。なお、この分岐度は、ポリラクトン化合物の酸価ＡＶ（ｍｇＫＯＨ／ｇ）により式：Ｍ＝（５６．１×ｆ_AV×１０００）／ＡＶから求められるポリラクトン化合物の分子量Ｍ（ここでｆ_AVはポリラクトン化合物１分子中の−ＣＯＯＨ基の数）及びポリラクトン化合物のヒドロキシル価ＯＨＶ（ｍｇＫＯＨ／ｇ）より式：分岐度＝（ＯＨＶ×Ｍ／５６．１×１００００）−１＝（ＯＨＶ×ｆ_AV／ＡＶ）−１により与えられる。
【００１５】
ポリラクトン化合物は、ヒドロキシカルボン酸およびラクトン類を脱水管、コンデンサーの接続した反応器に仕込み、触媒を添加しラクトン類を開環重合脱水、エステル交換することにより合成することができる。
【００１６】
このエステル交換の反応温度は、通常９０〜２５０℃、好ましくは１２０〜２３０℃の範囲である。反応温度が９０℃未満では反応速度がきわめて遅く、一方２３０℃を超えるとラクトン類の開環反応以外の副反応、たとえばラクトン類の環状ダイマーの生成反応や、脱水縮合反応が起こりやすいため、目標の分子量のカルボキシル基末端ポリラクトン類が合成しにくく、さらに、反応物の分解や着色が起こりやすいので好ましくない。
【００１７】
エステル化触媒としては、オクチル酸スズ、ジブチルスズオキシド、ジブチルスズラウレート、モノブチルスズヒドロキシブチルオキシド等の有機スズ化合物、酸化第一スズ、塩化第一スズ等のスズ化合物、テトラブチルチタネート、テトラエチルチタネート、テトラプロピルチタネート等が使用できる。触媒の使用量は、通常、０．１〜１０００ｐｐｍ、好ましくは１〜１００ｐｐｍである。触媒量が１０００ｐｐｍを超えると、樹脂の着色が激しくなり、製品の安定性に悪影響を与える恐れがある。逆に、触媒の使用量が１ｐｐｍ未満であるとラクトン類の開環重合速度やエステル化反応速度がきわめて遅くなるので好ましくない。
【００１８】
また、空気存在下で反応すると着色する傾向があるので、窒素気流下等の不活性雰囲気下でエステル交換反応させることが好ましい。
【００１９】
本発明では、上記の分岐構造含有カルボキシル基末端ポリラクトン化合物とポリアミン化合物を反応させて顔料分散剤を合成する。本発明に使用されるポリアミンは、その数平均分子量が１００〜２００００であることが好ましい。分子量が１００未満では顔料の吸着部分の分子量が低すぎて、ポリアミン化合物を使用した効果が得られないことがあり、また分子量が２００００を超えると、顔料分散剤全体の分子量が大きくなりすぎ、逆に顔料粒子間の会合を招いたり、分散性の低下をまねく可能性がある。ポリアミン化合物としては種々の化合物が使用できるが、分散剤とした場合の性能に優れ、また工業的にも入手しやすいポリエチレンイミンが好ましい。
【００２０】
ポリラクトン化合物とポリアミン化合物の反応比率はカルボキシル基とアミノ基のモル比が１：１から１：９９の範囲となるようにすることが好ましい。
【００２１】
このアミド化反応はポリアミンとポリラクトン化合物を脱水管、コンデンサーの接続した反応器に仕込み、適当な脱水溶媒、たとえばトルエン、キシレンの存在下に脱水縮合させるか、または窒素気流下で反応させることにより行うことができる。アミド化反応の温度は、通常９０〜２１０℃、好ましくは１００〜１７０℃の範囲である。９０℃未満の温度では、アミド化反応の速度がきわめて遅く、また２１０℃を超えると、反応物の分解や着色が起こりやすいので好ましくない。
【００２２】
穏和な反応条件下、すなわち低い反応温度あるいは短い反応時間では、アミノ基とカルボキシル基との塩が形成され、厳しい反応条件下、すなわち高い反応温度あるいは長い反応時間ではアミド結合が形成される。従って、合成される分散剤は、アミド、アミノ基とカルボキシル基との塩、または、それら両方の混在となることがあり、これらはすべて本発明の範囲に包含される。また、アミド化反応終了後、ジメチル硫酸の様な適当なアルキル化剤を使用することにより、アミノ基の一部を４級アンモニウム塩にしてもよい。
【００２３】
アミド化反応はキシレン、トルエンなどの芳香族溶剤、あるいはＭＩＢＫ、アノンなどのケトン系溶剤のような、ラクトン類と反応しない適当な溶剤中で行うことが出来る。反応に使用した溶剤は除いてもよく、またそのまま製品として使用することもできる。また、アミド化触媒としてはオクチル酸スズ、ジブチルスズオキシド、ジブチルスズラウレート、モノブチルスズヒドロキシブチルオキシド等の有機スズ化合物、酸化第一スズ、塩化第一スズ等のスズ化合物、テトラブチルチタネート、テトラエチルチタネート、テトラプロピルチタネート等のチタン化合物、ｐ−トルエンスルホン酸、メタンスルホン酸等の有機酸または硫酸、燐酸等の無機酸が使用できる。
【００２４】
触媒の使用量は、反応系中の重量基準で、通常０．１〜１０００ｐｐｍ、好ましくは１〜１００ｐｐｍである。触媒量が１０００ｐｐｍを超えると、樹脂の着色が激しくなり、製品の安定性に悪影響を与える。逆に、触媒の使用量が０．１ｐｐｍ未満になるとポリラクトン化合物と、ポリアミン化合物とのアミド化反応の速度がきわめて遅くなるので好ましくない。
【００２５】
また、空気存在化で反応すると着色する傾向があるので、窒素気流下等の不活性雰囲気下で反応させることが望ましい。
【００２６】
このようにして合成された分散剤は、ポリラクトン末端がヒドロキシル基で終了している。このヒドロキシル基が、塗料化後の焼付け工程において、メラミン樹脂またはイソシアネートと反応することにより、本分散剤は、塗膜の一部として強固に組み込まれる。このため、塗膜中の分散剤のブリードまたは結晶化が起こらず、また、この分散剤によって捕捉される顔料は、ブリードまたは顔料の再凝集が起こりにくい。
【００２７】
また、適当な分子量の分散剤を使用することにより、アルコール類のような比較的極性の高い溶剤を使用した顔料分散にも適用することが可能である。
【００２８】
本発明で提供される分散剤は、酸化チタン、酸化亜鉛、硫化カドミウム、黄色酸化鉄、べんがら、黄鉛、カーボンブラック等の無機顔料、フタロシアニン類、不溶性アゾ顔料、アゾレーキ顔料、縮合多環系顔料（スレン系、インジゴ系、ペリレン系、ペリノン系、フタロン系、ジオキサジン系、キナクリドン系、イソインドリノン系、ジケトピロロピロール系顔料）、および、磁性粉等について優れた分散性を有し、また製造されたミルベースは流動性、保存安定性が良好である。
【００２９】
本発明によれば、従来使用されていたものよりもアミノ基含有量が高く、優れた性能を有する顔料分散剤を製造することが可能となる。また、分岐構造を有するポリラクトン化合物は同程度の分子量の直鎖状のラクトン重合体に比較して結晶性が低く、この結果、本発明により製造される顔料分散剤の結晶性を抑えることが可能となり、塗料に配合した際、分散剤が結晶化し塗膜の光沢を損なうといった問題が起こりにくい。
【００３０】
さらに、特開昭６１−１７４９３９号公報および特開昭６３−１９７５２９号公報に記載の製造方法のように、カルボン酸でラクトン類を開環する工程を経ないため、高分子量のラクトンホモポリマーが含有されない。このため、本発明によれば、各種ビヒクルに対し相溶性が高く、塗料あるいはインキ中で分散剤が結晶化することがなく、優れた塗膜外観を与え、塗料と金属面との密着性も損なわず、そして、顔料に吸着するアミノ基の含有量が高い、顔料分散性能に優れた分散剤を容易に製造できる。
【００３１】
【実施例】
以下、実施例によって本発明をさらに詳細に説明するが、本発明はこれら実施例のみに限定されるものではない。なお、「部」は重量部を意味する。
【００３２】
なお、ＯＨ価、酸価、アミン価は、以下に記載の方法によって測定したものである。
(1)ＯＨ価：ＪＩＳ Ｋ−１５５７に準拠した。
(2)酸価：ＪＩＳ Ｋ−１５５７に準拠した。
(3)アミン価：塩酸による滴定法により求めた。
【００３３】
（製造例１：中間体ポリラクトン化合物の合成（中間体１））
コンデンサー、窒素導入管、かくはん機、温度計および脱水管を備えた２Ｌ反応機に、ジメチロールプロピオン酸１７８．８部、ε−カプロラクトン８４３．５部およびテトラブチルチタネート０．１部を仕込み、窒素気流下、１７０度で反応させ、残存するカプロラクトンが１％以下になった後、２１０℃で、酸価が５．６ＫＯＨｍｇ／ｇになるまで加熱、脱水縮合しポリラクトン化合物を合成した。得られた中間体１のポリラクトン化合物のＯＨ価は８１ＫＯＨｍｇ／ｇであった。
【００３４】
（製造例２：中間体ポリラクトン化合物の合成（中間体２））
コンデンサー、窒素導入管、かくはん機、温度計および脱水管を備えた２Ｌ反応機にジメチロールプロピオン酸２６８．０部、ε−カプロラクトン７６６．２部およびテトラブチルチタネート０．１部を仕込み、窒素気流下、１７０度で反応させ、残存するカプロラクトンが１％以下になった後、２１０℃で、酸価が５．８ＫＯＨｍｇ／ｇになるまで加熱、脱水縮合しポリラクトン化合物を合成した。得られた中間体２のポリラクトン化合物のＯＨ価は１１５ＫＯＨｍｇ／ｇであった。
【００３５】
（実施例１：分散剤の合成）
コンデンサー、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機に中間体１を１０００部仕込み、ついでポリエチレンイミン（日本触媒工業社製 ｓｐ−２００、数平均分子量１００００）を７４部仕込み、１２０℃で反応させた。アミン価が４１ｍｇＫＯＨ／ｇとなったところで反応を停止した。ＮＭＲにより求めた反応生成物のポリエステル鎖の数平均分子量は約１５００であった。
【００３６】
（実施例２：分散剤の合成）
コンデンサー、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機に中間体１を１０００部仕込み、ついでポリエチレンイミン（日本触媒工業社製 ｓｐ−２００、数平均分子量１００００）を１２３部仕込み、１２０℃で反応させた。アミン価が８０ｍｇＫＯＨ／ｇとなったところで反応を停止した。ＮＭＲにより求めた反応生成物のポリエステル鎖の数平均分子量は約１５００であった。
【００３７】
（実施例３：分散剤の合成）
コンデンサー、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機に中間体２を１０００部仕込み、ついでポリエチレンイミン（日本触媒工業社製 ｓｐ−２００、数平均分子量１００００）を９５部仕込み、１２０℃で反応させた。アミン価が４０ｍｇＫＯＨ／ｇとなったところで反応を停止した。ＮＭＲにより求めた反応生成物のポリエステル鎖の数平均分子量は約１０００であった。
【００３８】
（実施例４：分散剤の合成）
コンデンサー、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機に中間体２を１０００部仕込み、ついでポリエチレンイミン（日本触媒工業社製 ｓｐ−２００、数平均分子量１００００）を１４３部仕込み、１２０℃で反応させた。アミン価が８０ｍｇＫＯＨ／ｇとなったところで反応を停止した。ＮＭＲにより求めた反応生成物のポリエステル鎖の数平均分子量は約１０００であった。
【００３９】
（実施例５：分散ペーストの製造）
キナクリドン（大日精化工業社製 クロモファインレッド６８２０：Ｃ．Ｉ−Ｐｉｇｍｅｎｔ Ｖｉｏｌｅｔ１９）３５部、実施例２の分散剤３部、ＭＩＢＫ３３．５部、キシレン３３．５部およびガラスビーズ１００部を分散機（レッドデビル社製）で６０分間分散させた。分散ペーストは、良好な流動性を示し、１週間経過後も、流動性を示した。
【００４０】
（実施例６：分散ペーストの製造）
カーボンブラック（デッグサ社製 ＦＷ２００：Ｃ．Ｉ−Ｐｉｇｍｅｎｔ Ｂｌａｃｋ ７）２０部、実施例１の分散剤１０部、キシレン７０部およびガラスビーズ１００部を分散機（レッドデビル社製）で６０分間分散させた。分散ペーストは、良好な流動性を示し、１週間経過後も、流動性を示した。
【００４１】
（実施例７：分散ペーストの製造）
フタロシアニンブルー（大日精化工業社製 クロモファインブルー４９２０：Ｃ．Ｉ−Ｐｉｇｍｅｎｔ Ｂｌｕｅ１５：３）４５部、実施例３の分散剤４部、キシレン２５．５部，ブチルセロソルブアセテート２５．５部およびガラスビーズ１００部を分散機（レッドデビル社製）で１時間分散させた。分散ペーストは、良好な流動性を示し、１週間経過後も、流動性を示した。
【００４２】
（実施例８：分散ペーストの製造）
ジケトピロロピロール（チバガイギー社製 ＩＲＧＡＺＩＮ ＤＰＰ ＲｅｄＢＯ：Ｃ．Ｉ−Ｐｉｇｍｅｎｔ Ｒｅｄ２５４）４０部、実施例４の分散剤３部、ＭＩＢＫ３３．５部，キシレン３３．５部およびガラスビーズ１１０部を分散機（レッドデビル社製）で６０分間分散させた。分散ペーストは、良好な流動性を示し、１週間経過後も、流動性を示した。
【００４３】
（製造例３：中間体ポリエステルの合成（中間体３））
コンデンサー、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機にカプロン酸１１６部、カプロラクトンモノマー１３７９部およびテトラブチルチタネート２部を仕込み、窒素気流下、１８５℃で１８時間反応させた。得られた中間体３のポリカプロラクトンの酸価は３７．９ＫＯＨｍｇ／ｇであった。
【００４４】
（比較例１：分散剤の合成）
コンデンサー、脱水管、窒素導入管、かくはん機および温度計を備えた２Ｌ反応機に製造例３の中間体３を１０００部仕込み、ついでポリエチレンイミン（日本触媒工業社製 ｓｐ−２００、数平均分子量１００００）を７４部、脱水溶剤としてトルエン６００ｃｃを仕込み、１５０℃で反応させた。脱水された水の量が１４ｃｃとなったところで反応を停止した。生成物（トルエン溶液）の一部の溶剤除去後のアミン価は４２ＫＯＨｍｇ／ｇであった。
【００４５】
（比較例２：分散ペーストの製造）
カーボンブラック（デッグサ社製 ＦＷ２００：Ｃ．Ｉ−Ｐｉｇｍｅｎｔ Ｂｌａｃｋ ７）２０部、比較例１の分散剤１０部、キシレン７０部、ガラスビーズ１００部を分散機（レッドデビル社製）で６０分間分散させた。分散ペーストは、流動性を示した。
【００４６】
＜塗料評価＞
実施例６および比較例２で製造した分散ペーストを、表−１に示した配合組成で塗料化し、配合直後の塗料および低温放置（０℃、３日間）後の塗料で作製した塗膜の表面光沢度の測定（６０度）を行った。
【００４７】
【表１】

【００４８】
【発明の効果】
本発明に係る特定の顔料分散剤は、分岐骨格を有するポリラクトン部分を用いているので、該分散剤を用いて様々な顔料を分散させた分散液は良好な分散性を示し、特に塗料や印刷インキに適し、また、低温にて放置していても分散剤が結晶化することがない。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dispersion using a specific dispersant that improves the dispersibility of pigments and the like in the production of paints and inks.
[0002]
[Prior art]
In the production of paints and inks, various dispersants are used for the purpose of improving the dispersibility of pigments, improving the storage stability of paints, preventing color separation, and improving the gloss of a coating film. For these purposes, a dispersant having a structure in which a polyamine compound and a polyester or acrylic resin are bonded is disclosed in JP-A-61-174939, JP-A-63-197529, and JP-A-54-37082. JP, 48-79178, A, etc.
[0003]
As described in JP-A-54-37082 and JP-A-48-79178, a dispersant using a polyester obtained by dehydration condensation of a long-chain aliphatic hydroxycarboxylic acid such as 12-hydroxystearic acid is various. Although it has a wide dispersion performance with respect to pigments, a high-concentration pigment dispersion has not yet achieved satisfactory performance in terms of fluidity of the dispersion and coloring power of paints, inks, and the like. Furthermore, the dispersant having such a structure reduces the adhesion between the coating film and the metal surface when used in paints, inks and the like applied to metal.
[0004]
JP-A-61-174939 and JP-A-63-197529 describe a dispersant having a polyester chain obtained by ring-opening polymerization of a lactone such as caprolactone with a long-chain monocarboxylic acid. Yes. However, lactones are generally difficult to add to a carboxylic acid when a normal titanium or tin-based catalyst is used, and therefore unreacted carboxylic acid remains, and a high molecular weight lactone homopolymer, Alternatively, a carboxylic acid-modified lactone polymer having a much higher molecular weight than the design is produced. That is, since it is difficult to control the molecular weight of the lactone polymer that forms the steric repulsion layer in the dispersant, it is difficult to synthesize a dispersant having high dispersibility. Further, such a high molecular weight lactone polymer has high crystallinity, and when such a dispersant is used in the production of paints, inks, etc., during storage, the dispersant crystallizes in the paint or ink, and the coating film There is a problem of deteriorating the appearance.
[0005]
[Problems to be solved by the invention]
In a pigment dispersant composed of a polyamine compound and a polyester, the polyamine compound has a function of adsorbing to the pigment, and the polyester (lactone polymer) forms a three-dimensional repulsive layer around the pigment adsorbed by the polyamine compound. Have a role. In general, the polyamine compound in the pigment adsorbing layer is advantageous in that the content of adsorbing amino groups is high, and the lactone polymer that is a steric repulsion layer also has an appropriate molecular weight and a high content. It is advantageous. However, if the content of the lactone polymer is increased, the amino group that reacts with the carboxyl group of the lactone polymer to form an amide group increases, and the content of the amino group adsorbed on the pigment decreases. The problem arises that the dispersibility, mill base fluidity and storage stability are impaired.
[0006]
[Means for Solving the Problems]
As a result of intensive studies in view of the problems of the prior art, the present inventor has previously reported a dispersant synthesized by reacting a lactone polymer having a branched structure in the main chain portion with a polyamine compound. It has been found that a dispersant having a small amount is superior to a dispersant having a linear polyester chain, and that the mill base prepared using the dispersant has excellent fluidity and storage stability. That is, the present inventor can form an effective steric repulsion layer with less lactone polymer by adding a branched structure to the lactone polymer to be used, and further reduce the amount of amino groups forming amide groups. It has been found that it is possible to produce pigment dispersants having a group content. In addition, by having a highly branched structure, the polylactone polymer becomes low in crystallinity and becomes non-crystalline even when used as a dispersant, and is less likely to cause crystallization problems in the coating material. It was found that a film appearance can be obtained. Based on these findings, the present invention has been completed.
[0007]
That is, the first of the present invention is a branched structure-containing carboxyl group-terminated polylactone compound obtained by copolymerizing a monocarboxylic acid having two or more hydroxyl groups and a lactone compound represented by the following general formula (1). A dispersion obtained by dispersing a fine solid in an organic solvent using a dispersant obtained by reacting a polyamine compound with a polyamine compound is provided.
[0008]
[Chemical formula 2]

[0009]
A second aspect of the present invention is that in the dispersant, the molar ratio of the monocarboxylic acid having two or more hydroxyl groups and the lactone compound represented by the general formula (1) is 1:50 to 1: 1. A dispersion according to the first aspect of the present invention is provided.
According to a third aspect of the present invention, in the dispersant, the reaction product of the branched structure-containing carboxyl group-terminated polylactone compound and the polyamine compound is a salt, an amide, or a mixture thereof. The described dispersion is provided.
4th of this invention is a dispersion liquid in any one of 1st-3rd of this invention characterized by the number average molecular weights of a branched structure containing carboxyl group terminal polylactone compound being 100-5000 in a dispersing agent. I will provide a.
5th of this invention provides the dispersion liquid of any one of 1st-4th of this invention characterized by the number average molecular weights of a polyamine compound being 100 to 20000 in a dispersing agent.
A sixth aspect of the present invention provides the dispersion according to any one of the first to fifth aspects of the present invention, wherein in the dispersant, the polyamine compound is polyethyleneimine.
A seventh aspect of the present invention provides the dispersion according to any one of the first to sixth aspects of the present invention, wherein in the dispersant, the lactone compound is ε-caprolactone.
An eighth aspect of the present invention provides the dispersion according to any one of the first to seventh aspects of the present invention, wherein the fine solid is a pigment.
9th of this invention provides the dispersion liquid of any one of 1st-8 of this invention which is an object for coating materials.
A tenth aspect of the present invention provides the dispersion according to any one of the first to eighth aspects of the present invention, which is for printing ink.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The branched structure-containing carboxyl group-terminated polylactone compound (hereinafter also simply referred to as polylactone compound) has a general formula using a monocarboxylic acid having two or more hydroxyl groups (hereinafter also simply referred to as hydroxycarboxylic acid) as an initiator or a copolymerization component. It is obtained by ring-opening polymerization of the lactone compound represented by (1).
[0011]
As hydroxycarboxylic acid which can be used here, what is necessary is just to have two or more hydroxyl groups, and aliphatic, aromatic, and unsaturated hydroxycarboxylic acid can be used. Examples include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, 2,2-dimethylolpentanoic acid, dihydroxybenzoic acid, 4-hydroxyisophthalic acid, tartaric acid, gluconic acid 4,4-bis (hydroxyphenyl) butyric acid, 4,4-bis (hydroxyphenyl) valeric acid and the like can be used.
[0012]
Examples of the lactone compound include ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, β-propiolactone, γ-butyrolactone, 2-methylcaprolactone, 4-methylcaprolactone, and the like represented by the general formula (1). The lactones represented can be used. These may be used alone or in combination. In the general formula (1), the number of methyl groups is any number from 0 to 2 times the number of carbon atoms of the linear alkylene group, preferably 1 to 3. The number of carbon atoms of the linear alkylene group (excluding the side chain methyl group) is preferably 2 to 5.
[0013]
The number average molecular weight of a polylactone compound having a branched structure obtained by copolymerizing a hydroxycarboxylic acid having two or more hydroxyl groups and a lactone compound (also referred to as a branched structure-containing carboxyl group-terminated polylactone compound or simply a polylactone compound) is: Usually, it is in the range of 100 to 5000, preferably in the range of 500 to 3000. If the molecular weight of the polylactone compound is less than 100, a sufficient steric repulsion layer cannot be formed around the pigment, and if the molecular weight exceeds 5000, the molecular weight of the entire dispersant becomes too large, and the paint or ink vehicle This is not preferable because the compatibility of the toner is lowered and the pigment dispersibility is also lowered.
[0014]
The degree of branching in the polylactone compound is preferably 3 or more on average. If it is less than this, there is no effect of increasing the steric repulsion layer as compared with a linear polylactone chain, and the produced dispersant also tends to have high crystallinity. On the other hand, if the average degree of branching exceeds 20, the hydroxyl group content of the dispersant becomes too high and it is difficult to dissolve in a nonpolar solvent such as toluene or xylene. The degree of branching is determined by the molecular weight M of the polylactone compound obtained from the formula: M = (56.1 × f _AV × 1000) / AV based on the acid value AV (mg KOH / g) of the polylactone compound (where f _AV is the polylactone From the number of —COOH groups in one compound molecule) and the hydroxyl number OHV (mgKOH / g) of the polylactone compound, the formula: degree of branching = (OHV × M / 56.1 × 10000) −1 = (OHV × f _AV / AV ) -1.
[0015]
The polylactone compound can be synthesized by charging a hydroxycarboxylic acid and a lactone into a reactor connected to a dehydration tube and a condenser, adding a catalyst, ring-opening polymerization dehydration and transesterification of the lactone.
[0016]
The transesterification reaction temperature is usually in the range of 90 to 250 ° C, preferably 120 to 230 ° C. If the reaction temperature is less than 90 ° C, the reaction rate is very slow. On the other hand, if the reaction temperature exceeds 230 ° C, side reactions other than the ring-opening reaction of lactones, such as the formation reaction of cyclic dimers of lactones and dehydration condensation reactions, are likely to occur. It is difficult to synthesize a carboxyl group-terminated polylactone having a molecular weight of 2 and it is not preferable because the reaction product is easily decomposed and colored.
[0017]
Examples of esterification catalysts include tin compounds such as tin octylate, dibutyltin oxide, dibutyltin laurate, monobutyltin hydroxybutyl oxide, stannous oxide, stannous chloride, tetrabutyl titanate, tetraethyl titanate, tetra Propyl titanate can be used. The usage-amount of a catalyst is 0.1-1000 ppm normally, Preferably it is 1-100 ppm. When the amount of the catalyst exceeds 1000 ppm, the resin is intensely colored, which may adversely affect the stability of the product. Conversely, if the amount of the catalyst used is less than 1 ppm, the ring-opening polymerization rate and esterification reaction rate of lactones are extremely slow, which is not preferable.
[0018]
Moreover, since there exists a tendency to color when it reacts in air presence, it is preferable to make it transesterify in inert atmosphere, such as under nitrogen stream.
[0019]
In the present invention, a pigment dispersant is synthesized by reacting the branched structure-containing carboxyl group-terminated polylactone compound and the polyamine compound. The polyamine used in the present invention preferably has a number average molecular weight of 100 to 20000. If the molecular weight is less than 100, the molecular weight of the adsorbed portion of the pigment may be too low to obtain the effect of using a polyamine compound. If the molecular weight exceeds 20000, the molecular weight of the entire pigment dispersant becomes too large, In addition, there is a possibility of causing an association between pigment particles and a decrease in dispersibility. Various compounds can be used as the polyamine compound, and polyethyleneimine which is excellent in performance when used as a dispersant and easily available industrially is preferable.
[0020]
The reaction ratio of the polylactone compound and the polyamine compound is preferably such that the molar ratio of carboxyl group to amino group is in the range of 1: 1 to 1:99.
[0021]
This amidation reaction is carried out by charging a polyamine and a polylactone compound into a reactor connected to a dehydrating tube and a condenser and dehydrating and condensing them in the presence of an appropriate dehydrating solvent such as toluene and xylene, or by reacting them in a nitrogen stream. be able to. The temperature of the amidation reaction is usually 90 to 210 ° C, preferably 100 to 170 ° C. If the temperature is less than 90 ° C, the rate of the amidation reaction is extremely slow.
[0022]
Under mild reaction conditions, ie low reaction temperatures or short reaction times, salts of amino and carboxyl groups are formed, and amide bonds are formed under severe reaction conditions, ie high reaction temperatures or long reaction times. Therefore, the dispersant to be synthesized may be an amide, a salt of an amino group and a carboxyl group, or a mixture of both, and these are all included in the scope of the present invention. Further, after completion of the amidation reaction, a part of the amino group may be converted to a quaternary ammonium salt by using an appropriate alkylating agent such as dimethyl sulfate.
[0023]
The amidation reaction can be carried out in an appropriate solvent that does not react with lactones, such as aromatic solvents such as xylene and toluene, or ketone solvents such as MIBK and anone. The solvent used in the reaction may be removed, or the product can be used as it is. In addition, as an amidation catalyst, an organic tin compound such as tin octylate, dibutyltin oxide, dibutyltin laurate, and monobutyltin hydroxybutyl oxide, a tin compound such as stannous oxide and stannous chloride, tetrabutyl titanate, tetraethyl titanate, Titanium compounds such as tetrapropyl titanate, organic acids such as p-toluenesulfonic acid and methanesulfonic acid, or inorganic acids such as sulfuric acid and phosphoric acid can be used.
[0024]
The usage-amount of a catalyst is 0.1-1000 ppm normally on the basis of the weight in a reaction system, Preferably it is 1-100 ppm. When the amount of the catalyst exceeds 1000 ppm, the resin is vigorously colored and adversely affects the stability of the product. On the contrary, if the amount of the catalyst used is less than 0.1 ppm, the rate of the amidation reaction between the polylactone compound and the polyamine compound is extremely slow, which is not preferable.
[0025]
Moreover, since there exists a tendency which colors when it reacts by air presence, it is desirable to make it react in inert atmosphere, such as under nitrogen stream.
[0026]
The dispersant thus synthesized has a polylactone terminal terminated with a hydroxyl group. This hydroxyl group reacts with the melamine resin or isocyanate in the baking step after coating, whereby the present dispersant is firmly incorporated as a part of the coating film. For this reason, bleed or crystallization of the dispersant in the coating film does not occur, and the pigment captured by the dispersant is less likely to cause bleed or reaggregation of the pigment.
[0027]
Further, by using a dispersant having an appropriate molecular weight, it can be applied to pigment dispersion using a relatively polar solvent such as alcohols.
[0028]
Dispersants provided in the present invention include inorganic pigments such as titanium oxide, zinc oxide, cadmium sulfide, yellow iron oxide, brown rice, yellow lead, and carbon black, phthalocyanines, insoluble azo pigments, azo lake pigments, and condensed polycyclic pigments. (Slen, indigo, perylene, perinone, phthalone, dioxazine, quinacridone, isoindolinone, diketopyrrolopyrrole pigments) and magnetic powder etc. The manufactured mill base has good fluidity and storage stability.
[0029]
According to the present invention, it is possible to produce a pigment dispersant having an amino group content higher than that conventionally used and having excellent performance. In addition, the polylactone compound having a branched structure has lower crystallinity than a linear lactone polymer having the same molecular weight, and as a result, it is possible to suppress the crystallinity of the pigment dispersant produced by the present invention. Thus, when blended in a paint, problems such as crystallization of the dispersant and loss of gloss of the coating film are unlikely to occur.
[0030]
Furthermore, since the process of ring-opening lactones with carboxylic acids as in the production methods described in JP-A Nos. 61-174939 and 63-197529 is not performed, a high-molecular-weight lactone homopolymer is obtained. Not contained. Therefore, according to the present invention, it is highly compatible with various vehicles, the dispersant does not crystallize in the paint or ink, gives an excellent coating film appearance, and the adhesion between the paint and the metal surface is also good. It is possible to easily produce a dispersant which is not impaired and has a high amino group content adsorbed on the pigment and excellent in pigment dispersion performance.
[0031]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to these Examples. “Parts” means parts by weight.
[0032]
The OH value, acid value, and amine value are measured by the methods described below.
(1) OH value: Conforms to JIS K-1557.
(2) Acid value: Conforms to JIS K-1557.
(3) Amine value: determined by titration with hydrochloric acid.
[0033]
(Production Example 1: Synthesis of Intermediate Polylactone Compound (Intermediate 1))
A 2 L reactor equipped with a condenser, a nitrogen introducing tube, a stirrer, a thermometer and a dehydrating tube was charged with 178.8 parts of dimethylolpropionic acid, 843.5 parts of ε-caprolactone and 0.1 part of tetrabutyl titanate, and nitrogen. After reacting at 170 ° C. under an air stream, the remaining caprolactone was reduced to 1% or less, and then heated and dehydrated at 210 ° C. until the acid value reached 5.6 KOH mg / g to synthesize a polylactone compound. The OH value of the obtained intermediate 1 polylactone compound was 81 KOH mg / g.
[0034]
(Production Example 2: Synthesis of Intermediate Polylactone Compound (Intermediate 2))
A 2 L reactor equipped with a condenser, a nitrogen introducing tube, a stirrer, a thermometer and a dehydrating tube was charged with 268.0 parts of dimethylolpropionic acid, 766.2 parts of ε-caprolactone and 0.1 part of tetrabutyl titanate, and a nitrogen stream Then, after reacting at 170 ° C., the remaining caprolactone was 1% or less, and then heated and dehydrated at 210 ° C. until the acid value became 5.8 KOH mg / g, to synthesize a polylactone compound. The OH value of the obtained intermediate 2 polylactone compound was 115 KOH mg / g.
[0035]
(Example 1: Synthesis of dispersant)
A 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer was charged with 1000 parts of intermediate 1 and then with 74 parts of polyethyleneimine (Nippon Shokubai Co., Ltd. sp-200, number average molecular weight 10,000), 120 The reaction was carried out at ° C. The reaction was stopped when the amine value reached 41 mgKOH / g. The number average molecular weight of the polyester chain of the reaction product determined by NMR was about 1500.
[0036]
(Example 2: Synthesis of dispersant)
A 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer and a thermometer was charged with 1000 parts of intermediate 1, and then with 123 parts of polyethyleneimine (Nippon Shokubai Co., Ltd. sp-200, number average molecular weight 10,000). The reaction was carried out at ° C. The reaction was stopped when the amine value reached 80 mgKOH / g. The number average molecular weight of the polyester chain of the reaction product determined by NMR was about 1500.
[0037]
(Example 3: Synthesis of dispersant)
A 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer and a thermometer was charged with 1000 parts of intermediate 2 and then with 95 parts of polyethyleneimine (Nippon Shokubai Co., Ltd. sp-200, number average molecular weight 10,000), 120 The reaction was carried out at ° C. The reaction was stopped when the amine value reached 40 mgKOH / g. The number average molecular weight of the polyester chain of the reaction product determined by NMR was about 1000.
[0038]
(Example 4: Synthesis of dispersant)
A 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer and a thermometer was charged with 1000 parts of intermediate 2, and then with 143 parts of polyethyleneimine (Nippon Shokubai Co., Ltd., sp-200, number average molecular weight 10,000), 120 The reaction was carried out at ° C. The reaction was stopped when the amine value reached 80 mgKOH / g. The number average molecular weight of the polyester chain of the reaction product determined by NMR was about 1000.
[0039]
(Example 5: Production of dispersion paste)
Disperser containing 35 parts of quinacridone (Chromofine Red 6820: CI Pigment Violet 19 manufactured by Dainichi Seika Kogyo Co., Ltd.), 3 parts of the dispersant of Example 2, 33.5 parts of MIBK, 33.5 parts of xylene and 100 parts of glass beads. (Red Devil) for 60 minutes. The dispersion paste showed good fluidity and showed fluidity even after 1 week.
[0040]
(Example 6: Production of dispersion paste)
20 parts of carbon black (FW200: CI Pigment Black 7 manufactured by Deggsa), 10 parts of the dispersant of Example 1, 70 parts of xylene and 100 parts of glass beads were dispersed for 60 minutes by a disperser (manufactured by Red Devil). It was. The dispersion paste showed good fluidity and showed fluidity even after 1 week.
[0041]
(Example 7: Production of dispersion paste)
45 parts of phthalocyanine blue (Chromofine Blue 4920: CI Pigment Blue 15: 3 manufactured by Dainichi Seika Kogyo Co., Ltd.), 4 parts of the dispersant of Example 3, 25.5 parts of xylene, 25.5 parts of butyl cellosolve acetate and glass beads 100 parts were dispersed with a dispersing machine (manufactured by Red Devil) for 1 hour. The dispersion paste showed good fluidity and showed fluidity even after 1 week.
[0042]
(Example 8: Production of dispersion paste)
40 parts of diketopyrrolopyrrole (IRGAZIN DPP RedBO: CI Pigment Red254 manufactured by Ciba Geigy Co., Ltd.), 3 parts of the dispersant of Example 4, 33.5 parts of MIBK, 33.5 parts of xylene and 110 parts of glass beads ( (Manufactured by Red Devil) for 60 minutes. The dispersion paste showed good fluidity and showed fluidity even after 1 week.
[0043]
(Production Example 3: Synthesis of Intermediate Polyester (Intermediate 3))
116 parts of caproic acid, 1379 parts of caprolactone monomer and 2 parts of tetrabutyl titanate were charged into a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer and a thermometer, and reacted at 185 ° C. for 18 hours under a nitrogen stream. The acid value of the resulting intermediate 3 polycaprolactone was 37.9 KOH mg / g.
[0044]
(Comparative Example 1: Synthesis of dispersant)
Into a 2 L reactor equipped with a condenser, a dehydrating tube, a nitrogen introducing tube, a stirrer and a thermometer, 1000 parts of intermediate 3 of Production Example 3 was charged, and then polyethyleneimine (Nippon Shokubai Co., Ltd. sp-200, number average molecular weight 10,000) ) Was added in an amount of 74 parts, and 600 cc of toluene as a dehydrating solvent was reacted at 150 ° C. The reaction was stopped when the amount of dehydrated water reached 14 cc. The amine value after removal of a part of the product (toluene solution) was 42 KOH mg / g.
[0045]
(Comparative Example 2: Production of dispersion paste)
20 parts of carbon black (FW200: CI Pigment Black 7 manufactured by Deggsa), 10 parts of the dispersant of Comparative Example 1, 70 parts of xylene, and 100 parts of glass beads were dispersed for 60 minutes with a disperser (manufactured by Red Devil). It was. The dispersion paste showed fluidity.
[0046]
<Paint evaluation>
The dispersion paste produced in Example 6 and Comparative Example 2 was converted into a paint with the composition shown in Table 1, and the surface of the coating film prepared with the paint immediately after the composition and the paint after being left at low temperature (0 ° C., 3 days) The glossiness was measured (60 degrees).
[0047]
[Table 1]

[0048]
【The invention's effect】
Since the specific pigment dispersant according to the present invention uses a polylactone moiety having a branched skeleton, a dispersion in which various pigments are dispersed using the dispersant exhibits good dispersibility, particularly in paints and printing. Suitable for ink, and the dispersant does not crystallize even when left at low temperature.

Claims (10)

It is obtained by reacting a polyamine compound with a branched structure-containing carboxyl group-terminated polylactone compound obtained by copolymerizing a monocarboxylic acid having two or more hydroxyl groups and a lactone compound represented by the following general formula (1). A dispersion obtained by dispersing a fine solid in an organic solvent using a dispersant.

2. The dispersant according to claim 1, wherein the molar ratio of the monocarboxylic acid having two or more hydroxyl groups and the lactone compound represented by the general formula (1) is 1:50 to 1: 1. Dispersion. 3. The dispersion according to claim 1, wherein the reaction product of the branched structure-containing carboxyl group-terminated polylactone compound and the polyamine compound is a salt, an amide, or a mixture thereof. The dispersion according to any one of claims 1 to 3, wherein in the dispersant, the number average molecular weight of the branched structure-containing carboxyl group-terminated polylactone compound is 100 to 5,000. The dispersion liquid according to any one of claims 1 to 4, wherein the polyamine compound has a number average molecular weight of 100 to 20000 in the dispersant. The dispersion liquid according to claim 1, wherein the polyamine compound is polyethyleneimine in the dispersant. The dispersion liquid according to claim 1, wherein the lactone compound is ε-caprolactone in the dispersant. The dispersion liquid according to any one of claims 1 to 7, wherein the fine solid is a pigment. The dispersion according to any one of claims 1 to 8, which is used for paint. It is an object for printing ink, The dispersion liquid of any one of Claims 1-8.