JP2004107543A

JP2004107543A - Method for producing amide-based paste-like thixotropy-imparting agent and amide-based paste-like thixotropy-imparting agent produced by the same method

Info

Publication number: JP2004107543A
Application number: JP2002274234A
Authority: JP
Inventors: Kenji Komazawa; 駒澤　謙史; Takashi Hamaguchi; 浜口　隆司; Masatsugu Akita; 秋田　政継
Original assignee: Itoh Seiyu KK
Current assignee: Itoh Seiyu KK
Priority date: 2002-09-20
Filing date: 2002-09-20
Publication date: 2004-04-08
Anticipated expiration: 2022-09-20
Also published as: JP4408196B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide the amide-based paste-like thixotropy-imparting agent not containing a coarse-grained product and to provide a method for producing the agent. <P>SOLUTION: The method for producing the thixotropy-imparting agent not containing the coarse-grained product comprises reacting an unreacted amino group of a diamide component which is a condensation reaction product of a diamine with a hydrogenated castor oil fatty acid with a carboxy group of the unreacted fatty acid and an epoxy resin to lower amounts of components having low melting point and low molecular weight, atomizing the resultant diamide compound, dispersing the atomized diamide compound into a solvent and carrying out heat treatment of the dispersion. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、粗粒状生成物を含まないアミド系ペースト状揺変性付与剤の製造方法およびこの方法により製造されたアミド系ペースト状揺変性付与剤に関するものである。
【０００２】
【従来の技術】
【特許文献１】特開２００２−１４６３３６号
【０００３】
従来のアミド系ペースト状揺変性付与剤は、ペースト中に粗粒状物が生成する場合があり、この粗粒状生成物を含んだペーストを揺変性付与剤として塗料・インキ等に添加すると、分散不良等を生じるという問題があった。この問題を生じさせないためには、あらかじめ揺変性付与剤を加温して粗粒状生成物をペースト中に溶解させるか、揺変性付与剤を添加した樹脂液をろ過する等の作業が必要となり、手間がかかるという問題点があった。
【０００４】
そこで、例えば特許文献１にあるように、ペーストを作成する際の溶剤としてアルコール系溶剤（Ａ）と、環式飽和炭化水素およびエステルから選ばれる少なくとも１つの溶剤（Ｂ）とから成る混合溶剤を用いることにより粗粒状物を生成させないようにしたアミド系ペースト状揺変性付与剤が提案されている。ところが、この場合には溶剤が特定にものに限定されてしまうため、汎用性に劣るとともに使い勝手も劣るという問題点があった。
【０００５】
【発明が解決しようとする課題】
本発明は上記のような従来の問題点を解決して、分散不良等の問題を引き起こす原因となるペースト中の粗粒状物を含まず、従って加温やろ過などの粗粒状物除去作業を不要とすることができ、また溶剤の制限がなく優れた使い勝手を発揮することができるアミド系ペースト状揺変性付与剤の製造方法およびこの方法により製造されたアミド系ペースト状揺変性付与剤を提供することを目的として完成されたものである。
【０００６】
【課題を解決するための手段】
発明者らは、上記の課題を解決するため鋭意研究した結果、ジアミド化合物中のモノアミド化合物及び未反応脂肪酸をエポキシ樹脂と反応させることにより含有量を低下させたジアミド化合物を用いてペースト状揺変剤を作成すれば、粗粒状物が生成せず前記問題点を解決できることを見出した。
即ち、粗粒状生成物はジアミド化合物中に微量含まれるジアミンの片方のアミノ基と、水添ヒマシ油脂肪酸が反応したモノアミド化合物及び未反応脂肪酸が原因物質と考えられる。このようなモノアミド化合物及び未反応脂肪酸は、ジアミド化合物に比較して融点が低く分子量も小さいために、ペースト状揺変性付与剤製造工程中で溶剤中に分散させ加温処理した際に溶剤中に溶解しやすく、またペースト状揺変性付与剤が冬期の気温程度に冷却された場合に粗粒となって析出しやすいからである。
そこで、上記の課題を解決するためになされた本発明は、ジアミンと水添ヒマシ油脂肪酸との縮合反応生成物であるジアミド化合物の未反応アミノ基及び未反応脂肪酸のカルボキシル基を、エポキシ樹脂と反応させることにより低融点かつ低分子量の成分量を低下させ、得られたジアミド化合物を微粒子化させたのち溶剤中に分散させて、加温処理することを特徴とするアミド系ペースト状揺変性付与剤の製造方法と、この方法により製造されたことを特徴とする粗粒状生成物を含まないアミド系ペースト状揺変性付与剤である。
【０００７】
【発明の実施の形態】
本発明でいうエポキシ樹脂とは、１分子中に２個以上のエポキシ基を含む化合物をいい、グリシジルエーテル型、グリシジルエステル型、グリシジルアミン型、脂環型のいずれも含むものである。またジアミド化合物とは、ジアミンと水添ヒマシ油脂肪酸とを当量反応させて得られる縮合反応生成物である。
このジアミド化合物中には未反応物として、ジアミンの片方のアミノ基と水添ヒマシ油脂肪酸が反応したモノアミド化合物及び未反応脂肪酸が微量含まれることは避けられない。
上記モノアミド化合物及び未反応脂肪酸は、ジアミド化合物に比較して融点が低くかつ分子量も小さいために、ペースト状揺変性付与剤製造工程中で溶剤中に分散させ加温処理した際に溶剤中に溶解しやすく、またペースト状揺変性付与剤が冬期の気温程度に冷却された場合に粗粒となって析出しやすいものである。
そして本発明では、粗粒状生成物はジアミド化合物中に微量含まれる未反応物が原因物質と推測し、上記未反応物をエポキシ樹脂と反応させることによって低融点かつ低分子量の成分量を低下させ、得られたジアミド化合物を微粒子化させた後、溶剤中に分散させ加温処理することによって、粗粒状生成物を含まないアミド系ペースト状揺変性付与剤を得たのである。
【０００８】
ジアミンとしては、炭素数２〜１２のものを単独あるいは２種以上を併せて用いることができる。また、本発明でいうジアミンとは、第１級アミンの他、２個のアミノ基の一方または両方がアルキル（またはアリール）置換されて、第２級アミンあるいは第３級アミンの形になったものを一部に含むものも包含するものである。
水添ヒマシ油脂肪酸は、ヒマシ油を水素添加して得られるヒマシ硬化油を加水分解して得られる脂肪酸で、水酸基が１２番目の炭素原子に結合しているＣ１８直鎖状脂肪酸である１２−ヒドロキシステアリン酸を約９０％含有する、融点約７５℃の固体脂肪酸である。更に、本発明でいう水添ヒマシ油脂肪酸は、高純度１００％１２−ヒドロキシステアリン酸で製造したものや、他の脂肪酸やアジピン酸のような多塩基酸を加えたものも包含する。
これら水添ヒマシ油脂肪酸とジアミンとの縮合反応生成物であるジアミド化合物は、１モルの脂肪酸に対し０．５モルのジアミンを常圧もしくは真空下で、１６０〜２３０℃の温度で２〜１０時間反応させて得られる。このようにして得られたジアミド化合物は、一般に酸価および全アミン価が５ｍｇＫＯＨ／ｇ前後の数値となるが、反応温度を高くしても反応時間を延長してもこれ以下の数値にすることは難しく、未反応アミノ基及び未反応脂肪酸のカルボキシル基が残存する。
【０００９】
本発明では、上記方法で得られたジアミド化合物の未反応アミノ基及び未反応脂肪酸のカルボキシル基含有量を低下させるために、エポキシ樹脂をアミド反応終了後に添加し、１６０〜１８０℃で１時間程度反応させる。これにより。エポキシ樹脂と反応後のジアミド化合物の酸価および全アミン価は３ｍｇＫＯＨ／ｇ以下程度に低下し、融点１００〜１５０℃の淡黄色〜淡褐色の固体となる。このジアミド化合物をジェットミル等の乾式粉砕機等で、平均粒子径１０μｍ以下に微粒子化する。
【００１０】
ジアミド化合物の未反応アミノ基及び未反応脂肪酸のカルボキシル基含有量を低下させるために添加されるエポキシ樹脂は、分子量３００〜１０００の範囲が好ましい。これは分子量３００未満のエポキシ樹脂を使用した場合は、未反応物とエポキシ樹脂の反応物の分子量が小さいために凝集力が強く、ペーストが低温になった場合に粗粒になりやすく、一方、分子量１０００より大きいエポキシ樹脂を使用した場合は、未反応物とエポキシ樹脂の反応物の分子量が大きいため、ペースト加温時に膨潤せずに粗粒となってペースト中に残存してしまうおそれがあるからである。
【００１１】
上記目的のために添加されるエポキシ樹脂のジアミド化合物に対する添加量は１〜３重量％の範囲が好ましい。これは１重量％未満ではジアミド化合物中の未反応物量を充分に低下できないため粗粒が出やすく、一方、３重量％より多いと揺変性付与効果が低下し、目的とするペースト状揺変性付与剤が得られなくなるおそれがあるからである。
【００１２】
微粒子化したジアミド化合物の溶剤への分散は、適切な温度範囲で行う必要がある。適切な温度範囲とは、通常０〜５０℃、好ましくは１０〜４０℃の範囲である。
分散温度は使用する溶剤により異なるので、実際に懸濁液を作成し、その状態から最適な分散温度を決定する。適切な温度範囲に満たない低い温度で分散を行った場合、分散後の懸濁液中で分散粒子の沈降が起こり、不均一なペーストとなる。一方、適切な温度範囲を超える高い温度で分散を行った場合、微粒子の一部が溶解し、目的のペースト状揺変性付与剤が得られない。
また、溶剤へ分散する際、微粒子化したジアミド化合物は全配合量中の５〜５０重量％、好ましくは１０〜３０重量％となるように配合する。
【００１３】
ジアミド化合物微粒子を分散する溶剤としては特に制限はなく、トルエンやキシレン等の芳香族炭化水素、ミネラルスピリット等の脂肪族炭化水素、メチルシクロヘキサン、エチルシクロヘキサン等の環状飽和炭化水素、酢酸プロピル、酢酸ヘキシル等の酢酸エステルやプロピオン酸系エステル等を単独あるいは２種以上を併せて用いることができる。また、上記溶剤にメタノール、エタノール等の脂肪族アルコールやベンジルアルコール等の環状アルコールなどを混合するとペーストを加温した際のジアミド化合物の膨潤を促進し、目的とするペースト状揺変性付与剤を得るのに好ましい。
【００１４】
なお、炭化水素系溶剤及びエステル系溶剤の使用量は、全配合量中の１０〜９０重量％が好ましく、アルコール系溶剤の使用量は、全配合量中の５〜４０重量％が好ましい。また、懸濁液の加温処理温度は３０〜１００℃、好ましくは４０〜７０℃の範囲である。
【００１５】
温度、時間等の加温処理条件は使用する溶剤により異なるので、実際に懸濁液を加温処理し、その状態から最適な加温処理条件を決定する。適切な温度範囲に満たない低い温度で加温処理を行うと、塗料添加時に十分な揺変性を付与できないペーストしか得られず、一方、適切な温度範囲を超える高い温度で加温処理を行うと、微粒子の一部が溶剤中に溶解しペーストが冷却された際に粗粒となるおそれがある。
懸濁液の加温処理時間は１〜７２時間、好ましくは１２〜４８時間の範囲である。適切な処理時間に満たない短い時間で加温処理を行った場合、塗料添加時に十分な揺変性を付与できないペーストしか得られず、一方、適切な処理時間を超える長時間の加温処理を行った場合、塗料に添加した際に分散が困難なほど堅いペーストとなってしまうからである。
【００１６】
以下に、本発明の実施例について説明するが、本発明はこれらに限定されるものでないことは勿論である。
先ず、以下の合成例１〜合成例６に従い、微粒子化したジアミド化合物を合成した。
【００１７】
＜合成例１＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）とヘキサメチレンジアミン５８ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃で４時間アミド化反応させた後１６０℃まで冷却し、分子量約９００、エポキシ当量約４７５のエポキシ樹脂１０．５ｇ（ジアミド化合物の３重量％）を投入し、１６０℃で１時間反応させる。反応終了したジアミド化合物を、ジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００１８】
＜合成例２＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）とヘキサメチレンジアミン５８ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃で４時間アミド化反応させた後１６０℃まで冷却し、分子量約３８０、エポキシ当量約１９０のエポキシ樹脂３．５ｇ（ジアミド化合物の１重量％）を投入し、１６０℃で１時間反応させる。反応終了したジアミド化合物を、ジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００１９】
＜合成例３＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）と１，４−ジアミノブタン４４ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃で４時間アミド化反応させた後１６０℃まで冷却し、分子量約９００、エポキシ当量約４７５のエポキシ樹脂１０．５ｇ（ジアミド化合物の３重量％）を投入し、１６０℃で１時間反応させる。反応終了したジアミド化合物を、ジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００２０】
＜合成例４＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）とヘキサメチレンジアミン５８ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃、４時間でアミド化反応終了とし、得られたジアミド化合物をジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００２１】
＜合成例５＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）と１，４−ジアミノブタン４４ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃、４時間でアミド化反応終了とし、得られたジアミド化合物をジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００２２】
＜合成例６＞
温度計、水冷式コンデンサ、攪拌機および窒素ガス導入口を備えた容量１リットルの反応容器中に水添ヒマシ油脂肪酸３１０ｇ（１．０モル）とヘキサメチレンジアミン５８ｇ（０．５モル）を仕込み、窒素雰囲気下で攪拌しながら加熱して１２０℃程度で均一なアミン塩とする。次に、徐々に加熱して反応水を溜出しながら２００℃まで昇温する。２００℃で４時間アミド化反応させた後１６０℃まで冷却し、分子量約１４００、エポキシ当量約９５０エポキシ樹脂１０．５ｇ（ジアミド化合物の３重量％）を投入し、１６０℃で１時間反応させる。反応終了したジアミド化合物を、ジェットミル粉砕機で微粉砕し、平均粒子径７μｍの微粒子化したジアミド化合物を得た。
【００２３】
以上により得られた合成例１〜合成例６のジアミド化合物の分析結果は、表１に示すとおりである。
【００２４】
【表１】

【００２５】
次に、合成例により得られたジアミド化合物を用いた実施例につき説明する。
［実施例１］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１３０重量部、エタノール２２重量部、メタノール８重量部および合成例１のジアミド化合物微粉末４０重量部を加え、１０〜１５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００２６】
［実施例２］
〔懸濁液の作成〕
加温処理用の密閉容器に、酢酸プロピル１００重量部、イソプロピルアルコール６０重量部および合成例２のジアミド化合物微粉末４０重量部を加え、２５〜３０℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００２７】
［実施例３］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１３０重量部、エタノール２２重量部、メタノール８重量部および合成例３のジアミド化合物微粉末４０重量部を加え、１０〜１５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００２８】
実施例４〜１０
上記の実施例１〜３と同様に、合成例１および合成例３のジアミド化合物微粉末を用い、表２に示す条件で懸濁液の作成、加温処理をして得られたペースト状揺変性付与剤を実施例４〜１０とする。
【００２９】
一方、従来技術により得られるペースト状揺変性付与剤を比較例１〜比較例５として準備した。
［比較例１］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１３０重量部、エタノール２２重量部、メタノール８重量部および合成例４のジアミド化合物微粉末４０重量部を加え、１０〜１５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００３０】
［比較例２］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１３０重量部、エタノール２２重量部、メタノール８重量部および合成例５のジアミド化合物微粉末４０重量部を加え、１０〜１５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００３１】
［比較例３］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１４０重量部、エタノール４０重量部および合成例４のジアミド化合物微粉末２０重量部を加え、１５〜２０℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（６０℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００３２】
［比較例４］
〔懸濁液の作成〕
加温処理用の密閉容器に、ミネラルスピリット１３０重量部、ベンジルアルコール３０重量部および合成例５のジアミド化合物微粉末４０重量部を加え、２０〜２５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（６０℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００３３】
［比較例５］
〔懸濁液の作成〕
加温処理用の密閉容器に、キシレン１３０重量部、エタノール２２重量部、メタノール８重量部および合成例６のジアミド化合物微粉末４０重量部を加え、１０〜１５℃の温度で十分に分散させることにより、懸濁液を得た。
〔懸濁液の加温処理〕
懸濁液の入った密閉容器を、あらかじめ所定温度（５５℃）に設定した恒温槽内に４８時間静置し、その後室温で静置することにより冷却し、ペースト状揺変性付与剤を得た。
【００３４】
【表２】

【００３５】
実施例１〜１０と比較例１〜５で得られたアミド系ペースト状揺変性付与剤の性能評価を以下のとおり行った。
アクリル樹脂をキシレンで粘度２００ｍＰａ・ｓに調整した樹脂溶液に、ペースト状揺変性付与剤を固形分で１．０重量％添加し、ディスパー３０００ｒｐｍで３０分間分散した。分散液を２５℃で一晩静置した後、ＢＭ型粘度計で６０ｒｐｍおよび６ｒｐｍ時の粘度を測定した。Ｔ．Ｉ．値は６ｒｐｍ粘度／６０ｒｐｍ粘度の比で算出した。粒度はツブゲージを用いて測定した。
得られた結果を、表３に示す。
【００３６】
【表３】

【００３７】
また、ペースト中の粗粒状生成物発生状況について、以下の方法により確認試験を行った。
作成したペーストをあらかじめ−１０℃に１週間静置し、１週間経過後に２５℃で一晩静置してペーストを２５℃にする。次に、分散容器に５０ｇを採取して４５０ｇのキシレンを加え、ディスパー３０００ｒｐｍで３０分間分散する。分散液を３２５メッシュ（目開き４４μｍ）の金網でろ過し、金網を乾燥後に金網上の残査物を実体顕微鏡で観察することにより、粗粒状生成物の発生状況を確認した。
確認した結果を、表４に示す。
【００３８】
【表４】

これらの試験結果からも明らかなように、本発明のアミド系ペースト状揺変性付与剤が、従来技術である比較例と比べて同等の優れた揺変性付与効果を発揮することができ、しかも添加塗料中で分散不良となる粗粒状生成物を含まない優れた添加剤であることが確認できた。
【００３９】
【発明の効果】
以上の説明からも明らかなように、本発明は分散不良等の問題を引き起こす原因となるペースト中の粗粒状物を含まず、従って加温やろ過などの粗粒状物除去作業を不要とすることができ、また溶剤の制限がなく優れた使い勝手を発揮することができるものである。
よって本発明は従来の問題点を一掃したアミド系ペースト状揺変性付与剤の製造方法およびこの方法により製造されたアミド系ペースト状揺変性付与剤として、産業の発展に寄与するところは極めて大である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an amide-based paste-like thixotropic agent containing no coarse-grained product and an amide-based paste-like thixotropic agent produced by this method.
[0002]
[Prior art]
[Patent Document 1] JP-A-2002-146336
The conventional amide-based thixotropic agent may form coarse particles in the paste, and when a paste containing this coarse-grained product is added as a thixotropic agent to paints and inks, poor dispersion results. And so on. In order not to cause this problem, it is necessary to heat the thixotropic agent in advance to dissolve the coarse-grained product in the paste, or to filter the resin liquid to which the thixotropic agent is added, or the like. There was a problem that it took time and effort.
[0004]
Therefore, as disclosed in Patent Document 1, for example, a mixed solvent comprising an alcohol-based solvent (A) and at least one solvent (B) selected from cyclic saturated hydrocarbons and esters is used as a solvent for preparing a paste. An amide-based thixotropic agent has been proposed which is used to prevent the formation of coarse particles. However, in this case, since the solvent is limited to a specific solvent, there is a problem that the versatility is poor and the usability is poor.
[0005]
[Problems to be solved by the invention]
The present invention solves the conventional problems as described above, and does not include coarse particles in the paste that causes problems such as poor dispersion, and thus eliminates the need to remove coarse particles such as heating and filtration. And a method for producing an amide-based paste-like thixotropic agent capable of exhibiting excellent usability without limitation of a solvent, and an amide-based paste-like thixotropic agent produced by this method. It was completed for the purpose.
[0006]
[Means for Solving the Problems]
The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the monoamide compound and the unreacted fatty acid in the diamide compound were reacted with the epoxy resin to reduce the content of the paste, thereby using a diamide compound. It has been found that the above problem can be solved by preparing an agent without generating coarse particles.
That is, it is considered that the coarse-grained product is a monoamide compound in which one of the amino groups of the diamine contained in the diamide compound and a hydrogenated castor oil fatty acid have reacted, and an unreacted fatty acid. Such a monoamide compound and an unreacted fatty acid have a lower melting point and a lower molecular weight than the diamide compound, and thus are dispersed in a solvent during the paste-like thixotropic agent manufacturing process and heated in the solvent. This is because it is easy to dissolve, and the paste-like thixotropic agent tends to precipitate as coarse particles when cooled to about the winter temperature.
Then, the present invention made to solve the above-mentioned problem, the unreacted amino group of the diamide compound which is a condensation reaction product of diamine and hydrogenated castor oil fatty acid and the carboxyl group of the unreacted fatty acid, the epoxy resin and The amide-based paste-like thixotropy imparted by lowering the amount of the low-melting-point and low-molecular-weight components by reacting, dispersing the obtained diamide compound into fine particles, dispersing in a solvent, and heating. An amide-based thixotropic agent containing no coarse-grained product, characterized by a method for producing the agent, and a coarse-granular product not produced by this method.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The epoxy resin referred to in the present invention refers to a compound containing two or more epoxy groups in one molecule, and includes any of glycidyl ether type, glycidyl ester type, glycidylamine type and alicyclic type. The diamide compound is a condensation reaction product obtained by reacting a diamine and a hydrogenated castor oil fatty acid in equivalent amounts.
It is inevitable that the diamide compound contains, as unreacted substances, a monoamide compound in which one amino group of the diamine has reacted with hydrogenated castor oil fatty acid and a small amount of unreacted fatty acid.
Since the above monoamide compound and unreacted fatty acid have a lower melting point and a lower molecular weight than the diamide compound, they dissolve in the solvent when they are dispersed and heated in the paste-like thixotropic agent manufacturing process. When the paste-like thixotropic agent is cooled to about winter temperature, it becomes coarse particles and tends to precipitate.
In the present invention, the coarse-grained product is presumed to be caused by an unreacted substance contained in a small amount in the diamide compound, and the unreacted substance is reacted with an epoxy resin to reduce the amount of low melting point and low molecular weight components. The resulting diamide compound was micronized, dispersed in a solvent and heated to obtain an amide-based thixotropic agent containing no coarse-grained product.
[0008]
As the diamine, those having 2 to 12 carbon atoms can be used alone or in combination of two or more. Further, the diamine referred to in the present invention is a secondary amine or a tertiary amine in which one or both of two amino groups are substituted with an alkyl (or aryl) in addition to a primary amine. It also includes those that include some of them.
Hydrogenated castor oil fatty acid is a fatty acid obtained by hydrolyzing castor oil obtained by hydrogenating castor oil, and is a C18 linear fatty acid having a hydroxyl group bonded to the twelfth carbon atom. It is a solid fatty acid containing about 90% hydroxystearic acid and having a melting point of about 75 ° C. Further, the hydrogenated castor oil fatty acid referred to in the present invention includes those manufactured with high-purity 100% 12-hydroxystearic acid and those added with other fatty acids or polybasic acids such as adipic acid.
The diamide compound which is a condensation reaction product of the hydrogenated castor oil fatty acid and the diamine is prepared by adding 0.5 mol of diamine to 1 mol of fatty acid at a temperature of 160 to 230 ° C. under normal pressure or vacuum at a temperature of 2 to 10 ° C. It is obtained by reacting for hours. The diamide compound thus obtained generally has an acid value and a total amine value of around 5 mg KOH / g, but it should be lower than this value even if the reaction temperature is increased or the reaction time is extended. Is difficult, and unreacted amino groups and carboxyl groups of unreacted fatty acids remain.
[0009]
In the present invention, in order to reduce the unreacted amino group of the diamide compound obtained by the above method and the carboxyl group content of the unreacted fatty acid, an epoxy resin is added after the end of the amide reaction, and at 160 to 180 ° C. for about 1 hour. Let react. By this. The acid value and the total amine value of the diamide compound after the reaction with the epoxy resin are reduced to about 3 mgKOH / g or less, and a pale yellow to light brown solid having a melting point of 100 to 150 ° C is obtained. This diamide compound is finely divided into particles having an average particle diameter of 10 μm or less by a dry pulverizer such as a jet mill.
[0010]
The epoxy resin added to reduce the unreacted amino group of the diamide compound and the carboxyl group content of the unreacted fatty acid preferably has a molecular weight in the range of 300 to 1,000. This is because when an epoxy resin having a molecular weight of less than 300 is used, the cohesive force is strong due to the small molecular weight of the unreacted product and the reaction product of the epoxy resin, and the paste tends to be coarse when the paste is cooled, When an epoxy resin having a molecular weight of more than 1000 is used, the unreacted product and the reaction product of the epoxy resin have a large molecular weight, and thus may not remain in the paste as coarse particles without swelling when the paste is heated. Because.
[0011]
The amount of the epoxy resin added for the above purpose to the diamide compound is preferably in the range of 1 to 3% by weight. If the amount is less than 1% by weight, the amount of unreacted substances in the diamide compound cannot be sufficiently reduced, so that coarse particles tend to be produced. On the other hand, if the amount is more than 3% by weight, the effect of imparting thixotropic properties decreases, and the desired paste-like thixotropic properties are imparted. This is because the agent may not be obtained.
[0012]
The dispersion of the finely divided diamide compound in the solvent needs to be performed in an appropriate temperature range. The appropriate temperature range is usually from 0 to 50 ° C, preferably from 10 to 40 ° C.
Since the dispersion temperature varies depending on the solvent used, a suspension is actually prepared and the optimum dispersion temperature is determined from the state. When the dispersion is performed at a low temperature below the appropriate temperature range, sedimentation of dispersed particles occurs in the suspension after dispersion, resulting in a non-uniform paste. On the other hand, when the dispersion is performed at a high temperature exceeding the appropriate temperature range, some of the fine particles are dissolved, and the desired paste-like thixotropic agent cannot be obtained.
When dispersing in a solvent, the finely divided diamide compound is blended in an amount of 5 to 50% by weight, preferably 10 to 30% by weight based on the total amount.
[0013]
There is no particular limitation on the solvent in which the diamide compound fine particles are dispersed, and aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as mineral spirits, cyclic saturated hydrocarbons such as methylcyclohexane and ethylcyclohexane, propyl acetate, and hexyl acetate Or a combination of two or more thereof. Further, when the solvent is mixed with an aliphatic alcohol such as methanol or ethanol, or a cyclic alcohol such as benzyl alcohol, the swelling of the diamide compound when the paste is heated is promoted to obtain the desired paste-like thixotropic agent. Preferred for
[0014]
The amount of the hydrocarbon solvent and the ester solvent is preferably 10 to 90% by weight based on the total amount, and the amount of the alcoholic solvent is preferably 5 to 40% by weight based on the total amount. The heating temperature of the suspension is in the range of 30 to 100 ° C, preferably 40 to 70 ° C.
[0015]
Since the heating conditions such as temperature and time vary depending on the solvent used, the suspension is actually heated and the optimum heating conditions are determined from the state. When the heating treatment is performed at a low temperature below the appropriate temperature range, only a paste that cannot impart sufficient thixotropic property at the time of adding the paint can be obtained, while when the heating treatment is performed at a high temperature exceeding the appropriate temperature range. When the paste is cooled, some of the fine particles may dissolve in the solvent and become coarse particles.
The heating time of the suspension ranges from 1 to 72 hours, preferably from 12 to 48 hours. If the heating treatment is performed for a short time that is less than the appropriate treatment time, only a paste that cannot impart sufficient thixotropic property at the time of adding the paint can be obtained, while a long-time heating treatment that exceeds the appropriate treatment time is performed. In such a case, the paste becomes too hard to be dispersed when added to the paint.
[0016]
Hereinafter, examples of the present invention will be described, but it is needless to say that the present invention is not limited to these.
First, a finely divided diamide compound was synthesized according to Synthesis Examples 1 to 6 below.
[0017]
<Synthesis example 1>
In a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet, 310 g (1.0 mol) of hydrogenated castor oil fatty acid and 58 g (0.5 mol) of hexamethylenediamine were charged. The mixture is heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. After the amidation reaction at 200 ° C. for 4 hours, the mixture is cooled to 160 ° C., 10.5 g (3% by weight of the diamide compound) of an epoxy resin having a molecular weight of about 900 and an epoxy equivalent of about 475 is charged, and the reaction is carried out at 160 ° C. for 1 hour. . The diamide compound after the reaction was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0018]
<Synthesis Example 2>
In a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet, 310 g (1.0 mol) of hydrogenated castor oil fatty acid and 58 g (0.5 mol) of hexamethylenediamine were charged. The mixture is heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. After amidation reaction at 200 ° C. for 4 hours, the mixture is cooled to 160 ° C., and 3.5 g (1% by weight of the diamide compound) of an epoxy resin having a molecular weight of about 380 and an epoxy equivalent of about 190 is charged, and reacted at 160 ° C. for 1 hour. . The diamide compound after the reaction was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0019]
<Synthesis example 3>
310 g (1.0 mol) of hydrogenated castor oil fatty acid and 44 g (0.5 mol) of 1,4-diaminobutane in a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet. And heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. After the amidation reaction at 200 ° C. for 4 hours, the mixture is cooled to 160 ° C., 10.5 g (3% by weight of the diamide compound) of an epoxy resin having a molecular weight of about 900 and an epoxy equivalent of about 475 is charged, and the reaction is carried out at 160 ° C. for 1 hour. . The diamide compound after the reaction was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0020]
<Synthesis example 4>
In a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet, 310 g (1.0 mol) of hydrogenated castor oil fatty acid and 58 g (0.5 mol) of hexamethylenediamine were charged. The mixture is heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. The amidation reaction was completed at 200 ° C. for 4 hours, and the obtained diamide compound was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0021]
<Synthesis example 5>
310 g (1.0 mol) of hydrogenated castor oil fatty acid and 44 g (0.5 mol) of 1,4-diaminobutane in a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet. And heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. The amidation reaction was completed at 200 ° C. for 4 hours, and the obtained diamide compound was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0022]
<Synthesis example 6>
In a 1 liter reaction vessel equipped with a thermometer, a water-cooled condenser, a stirrer and a nitrogen gas inlet, 310 g (1.0 mol) of hydrogenated castor oil fatty acid and 58 g (0.5 mol) of hexamethylenediamine were charged. The mixture is heated with stirring under a nitrogen atmosphere to obtain a uniform amine salt at about 120 ° C. Next, the temperature is raised to 200 ° C. while gradually heating and distilling the reaction water. After an amidation reaction at 200 ° C. for 4 hours, the mixture is cooled to 160 ° C., and 10.5 g (3% by weight of the diamide compound) of an epoxy resin having a molecular weight of about 1400 and an epoxy equivalent of about 950 is charged, and reacted at 160 ° C. for 1 hour. The diamide compound after the reaction was finely pulverized with a jet mill pulverizer to obtain a finely divided diamide compound having an average particle diameter of 7 μm.
[0023]
The analysis results of the diamide compounds of Synthesis Examples 1 to 6 obtained as described above are as shown in Table 1.
[0024]
[Table 1]

[0025]
Next, examples using the diamide compound obtained in the synthesis example will be described.
[Example 1]
[Preparation of suspension]
130 parts by weight of xylene, 22 parts by weight of ethanol, 8 parts by weight of methanol and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 1 are added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 10 to 15 ° C. As a result, a suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0026]
[Example 2]
[Preparation of suspension]
100 parts by weight of propyl acetate, 60 parts by weight of isopropyl alcohol, and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 2 were added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 25 to 30 ° C. A suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0027]
[Example 3]
[Preparation of suspension]
130 parts by weight of xylene, 22 parts by weight of ethanol, 8 parts by weight of methanol and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 3 are added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 10 to 15 ° C. As a result, a suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0028]
Examples 4 to 10
In the same manner as in Examples 1 to 3 above, using the fine powder of the diamide compound of Synthesis Example 1 and Synthesis Example 3, a suspension was prepared and heated under the conditions shown in Table 2 to obtain a paste-like shaker. Examples 4 to 10 are modification modifiers.
[0029]
On the other hand, paste-like thixotropic agents obtained by conventional techniques were prepared as Comparative Examples 1 to 5.
[Comparative Example 1]
[Preparation of suspension]
130 parts by weight of xylene, 22 parts by weight of ethanol, 8 parts by weight of methanol and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 4 are added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 10 to 15 ° C. As a result, a suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0030]
[Comparative Example 2]
[Preparation of suspension]
130 parts by weight of xylene, 22 parts by weight of ethanol, 8 parts by weight of methanol and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 5 are added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 10 to 15 ° C. As a result, a suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0031]
[Comparative Example 3]
[Preparation of suspension]
140 parts by weight of xylene, 40 parts by weight of ethanol, and 20 parts by weight of the diamide compound fine powder of Synthesis Example 4 were added to a closed container for heating treatment, and the suspension was sufficiently dispersed at a temperature of 15 to 20 ° C. Got.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (60 ° C.) for 48 hours, and then cooled by leaving it at room temperature to obtain a paste-like thixotropic agent. .
[0032]
[Comparative Example 4]
[Preparation of suspension]
130 parts by weight of mineral spirit, 30 parts by weight of benzyl alcohol, and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 5 were added to a closed container for heating treatment, and the suspension was sufficiently dispersed at a temperature of 20 to 25 ° C. A suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (60 ° C.) for 48 hours, and then cooled by leaving it at room temperature to obtain a paste-like thixotropic agent. .
[0033]
[Comparative Example 5]
[Preparation of suspension]
130 parts by weight of xylene, 22 parts by weight of ethanol, 8 parts by weight of methanol and 40 parts by weight of the fine powder of the diamide compound of Synthesis Example 6 are added to a closed container for heating treatment, and sufficiently dispersed at a temperature of 10 to 15 ° C. As a result, a suspension was obtained.
(Heating treatment of suspension)
The closed container containing the suspension was allowed to stand in a constant temperature bath set at a predetermined temperature (55 ° C.) in advance for 48 hours, and then cooled at room temperature to obtain a paste-like thixotropic agent. .
[0034]
[Table 2]

[0035]
The performance of the amide-based thixotropic agent obtained in Examples 1 to 10 and Comparative Examples 1 to 5 was evaluated as follows.
To a resin solution prepared by adjusting the viscosity of an acrylic resin to 200 mPa · s with xylene, a paste-like thixotropic agent was added in an amount of 1.0% by weight in terms of solid content, and dispersed at 3,000 rpm for 30 minutes. After the dispersion was allowed to stand at 25 ° C. overnight, the viscosity at 60 rpm and 6 rpm was measured with a BM type viscometer. T. I. The value was calculated by the ratio of 6 rpm viscosity / 60 rpm viscosity. The particle size was measured using a tub gauge.
Table 3 shows the obtained results.
[0036]
[Table 3]

[0037]
In addition, a confirmation test was performed by the following method for the generation of coarse and granular products in the paste.
The prepared paste is allowed to stand at −10 ° C. for one week in advance, and after one week, the paste is allowed to stand at 25 ° C. overnight to bring the paste to 25 ° C. Next, 50 g is collected in a dispersion container, 450 g of xylene is added, and the dispersion is performed at 3000 rpm for 30 minutes. The dispersion was filtered through a 325-mesh (mesh opening: 44 μm) wire mesh, and after drying the wire mesh, the residue on the wire mesh was observed with a stereoscopic microscope to confirm the generation of coarse and granular products.
The results are shown in Table 4.
[0038]
[Table 4]

As is clear from these test results, the amide-based paste-like thixotropic agent of the present invention can exert the same excellent thixotropic effect as compared with the comparative example of the prior art, and furthermore, It was confirmed that the additive was an excellent additive that did not contain coarse-grained products that would cause poor dispersion in the paint.
[0039]
【The invention's effect】
As is clear from the above description, the present invention does not include coarse particles in the paste that causes problems such as poor dispersion, and thus eliminates the need to remove coarse particles such as heating and filtration. In addition, there is no limitation on the solvent, and excellent usability can be exhibited.
Therefore, the present invention, as a method for producing an amide-based paste-like thixotropic agent which has eliminated the conventional problems, and an amide-based paste-like thixotropic agent produced by this method, which greatly contribute to industrial development, are very large. is there.

Claims

The unreacted amino group of the diamide compound and the carboxyl group of the unreacted fatty acid, which are the condensation reaction product of the diamine and hydrogenated castor oil fatty acid, are reacted with the epoxy resin to reduce the amount of low melting point and low molecular weight components, A method for producing an amide-based paste-like thixotropic agent, comprising dispersing the obtained diamide compound into fine particles, dispersing in a solvent, and heating.

An amide-based thixotropic agent containing no coarse-grained product, which is produced by the method of claim 1.

The amide-based thixotropic agent according to claim 2, wherein the epoxy resin has an average molecular weight of 300 to 1,000.

The amide-based thixotropic agent according to claim 2 or 3, wherein the content of the epoxy resin with respect to the diamide compound is 1 to 3% by weight.