JP2004051969A - Method for producing organic pigment composition and pigment dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic pigment composition capable of coloring a medium to be colored with better coloring power than ever, by selecting only a surfactant having a specific chemical formula from many betaine-type ampholytic surfactants and using the surfactant together with an organic pigment. <P>SOLUTION: This method for producing the organic pigment composition comprises a first process for producing a crude pigment and a second process for pigmentizing the crude pigment obtained from the first process to form the organic pigment and conducts the first process and/or the second process in the presence of the betaine-type ampholytic surfactant so as to produce the organic pigment composition containing the betaine-type ampholytic surfactant and the organic pigment, wherein the betaine-type ampholytic surfactant expressed by formula (1) (R<SP>1</SP>is an 8-24C aliphatic hydrocarbon residue; and R<SP>2</SP>and R<SP>3</SP>are identical to or different from each other, and each H or methyl) is used. A pigment dispersion contains the organic pigment composition obtained by the method for producing the organic pigment composition and a dispersing medium. <P>COPYRIGHT: (C)2004,JPO

Description

【００１９】
〔尚、一般式（１）中、Ｒ^１は炭素原子数８〜２４の脂肪族炭化水素基であり、
Ｒ^２およびＲ^３は同一でも異なっていてもよい、水素原子またはメチル基である。〕
【００２０】
【発明の実施の形態】
本発明の有機顔料組成物の製造方法は、粗製顔料を製造する第１工程と、この第１工程で得られた粗製顔料を顔料化して有機顔料とする第２工程とからなり、前記第１工程及び／または第２工程を当該界面活性剤の存在下で行う、当該界面活性剤と有機顔料とを含有する有機顔料組成物の製造方法である。
【００２１】
本発明の製造方法で得られる有機顔料組成物は、当該界面活性剤と有機顔料とを含有するものである。
【００２２】
本発明における有機顔料は、公知慣用のものであるが、好適には中級または高級顔料である。この様な中級または高級顔料は、キナクリドン顔料、ジケトピロロピロール顔料、ベンツイミダゾロン系アゾ顔料、ペリレン顔料、ペリノン顔料、ジオキサジン顔料、イソインドリノン顔料、イソインドリン顔料、チオインジゴ顔料、キノフタロン顔料、アンスラキノン顔料からなる群から選ばれる１種以上の有機顔料が挙げられる。中でも、ベンツイミダゾロン系アゾ顔料の場合に、特に鮮明性、着色力及び透明性がいずれも優れた有機顔料組成物が得られる。
【００２３】
本発明における当該界面活性剤としては、前記一般式（１）に該当する公知慣用のものがいずれも使用できる。前記一般式（１）におけるＲ^２とＲ^３は、同一でも異なっていても良い、水素原子またはメチル基である。Ｒ^２とＲ^３とは、いずれも水素原子、水素原子とメチル基との組み合わせ、いずれもメチル基の３通りがある。Ｒ^１は炭素原子数８〜２４の脂肪族炭化水素基であり、例えば不飽和二重結合や不飽和三重結合を１から５個含んでいても良い炭化水素基である。
【００２４】
当該界面活性剤で最も一般的なアルキルジメチルアミノ酢酸ベタインは、前記一般式（１）におけるＲ^２とＲ^３がいずれもメチル基の物質である。
【００２５】
当該界面活性剤としては、例えばオクチルアミノ酢酸ベタイン、オクチルジメチルアミノ酢酸ベタイン、デシルジメチルアミノ酢酸ベタイン、ラウリルアミノ酢酸ベタイン、ラウリルジメチルアミノ酢酸ベタイン、ステアリルアミノ酢酸ベタイン、ステアリルジメチルアミノ酢酸ベタイン、エイコシルジメチルアミノ酢酸ベタイン、テトラコシルジメチルアミノ酢酸ベタイン等のＮ−モノ長鎖アルキルベタイン型両性界面活性剤、Ｎ−モノ長鎖アルキルモノメチルベタイン型両性界面活性剤、Ｎ−モノ長鎖アルキルジメチルベタイン型両性界面活性剤が挙げられる。
【００２６】
当該界面活性剤は、前記一般式（１）中のＲ^１が嵩高いほど（分子量が大きいほど）得られる有機顔料組成物の分散媒中での分散安定性が増すが、　逆に後に詳述する粗製顔料の製造工程において、粗製顔料を微細化する能力が小さくなる傾向にある。したがって、使用する粗製顔料および顔料分散体の調製に使用される分散媒並びに顔料分散体の用途に応じて適当な当該界面活性剤を選択して使用する事が望ましい。
【００２７】
当該界面活性剤を使用した場合の技術的効果は、有機顔料および分散媒の種類により変化するが、当該界面活性剤のＲ^１の炭素原子数１２以上である時に、特に分散媒中における有機顔料の分散安定化効果が大きくなる。従って、当該界面活性剤としては、Ｒ^２とＲ^３がいずれもメチル基であり、Ｒ^１が炭素原子数１２〜２４のアルキル基であるＮ−アルキルベタイン型両性界面活性剤を用いることが好ましい。
【００２８】
当該界面活性剤としては、例えば水溶液や含水スラリーとして市販されている、花王（株）製アンヒトール（登録商標）８６Ｂ〔前記一般式（１）において、Ｒ^１が炭素原子数１８のステアリル基である当該界面活性剤を含む〕、アンヒトール（登録商標）２０ＢＳ〔前記一般式（１）において、Ｒ^１が炭素原子数１２のラウリル基である当該界面活性剤を含む〕等が挙げられる。
【００２９】
当該界面活性剤の一般式（１）中のＲ^１の鎖長と改良効果が認められる評価項目との関係は、次の通りである。例えば、着色力の他に透明性の改良も課題とされる様な平版印刷用インキの分野においては、当該界面活性剤の同一使用量における対比で、当該界面活性剤の一般式（１）中のＲ^１が炭素原子数１２〜２４のアルキル基の範囲で、よりアルキル基の鎖長が短いほうが好ましい結果を与える。一方、着色力の他に粘度の改良も課題とされる様なグラビア印刷用インキの分野においては、当該界面活性剤の同一使用量における対比で、当該界面活性剤の一般式（１）中のＲ^１が炭素原子数１２〜２４のアルキル基の範囲で、よりアルキル基の鎖長が長いほうが好ましい結果を与える。
【００３０】
本発明の製造方法で得られる有機顔料組成物は、有機顔料と当該界面活性剤を含んでいれば、それらの比率は特に制限されるものではないが、質量換算で有機顔料１００部当たり、当該界面活性剤０．５〜１２部であることが好ましい。
【００３１】
本発明の製造方法には、粗製顔料を製造する第１工程と、この第１工程で得られた粗製顔料を顔料化して有機顔料とする第２工程とからなり、（１）前記第１工程を当該界面活性剤の存在下で行って、当該界面活性剤と有機顔料とを含有する有機顔料組成物を得る製造方法と、（２）前記第２工程を当該界面活性剤の存在下で行って、当該界面活性剤と有機顔料とを含有する有機顔料組成物の製造方法とが包含される。勿論、第１工程と第２工程との両方を当該界面活性剤の存在下で行うことも出来る。
【００３２】
しかしながら、少なくとも前記第１工程において、当該界面活性剤を用いる前記有機顔料組成物の製造方法が、鮮明性、着色力及び透明性のいずれにも優れる好適な有機顔料組成物が得られるので好ましい。
【００３３】
当該界面活性剤の鎖長と改良効果が認められる評価項目との前記した様な関係は、前記第１工程を当該界面活性剤の存在下で行う（１）の製造方法〔製造方法（１）という〕の場合でも、前記第２工程を当該界面活性剤の存在下で行う（２）の製造方法〔製造方法（２）という〕の場合でも発現する。
【００３４】
しかしながら、前記製造方法（１）の場合に、本発明における最適な有機顔料組成物を調製することが出来る。
【００３５】
本発明の有機顔料組成物の製造方法は、具体的には、前記製造方法（１）の場合には、粗製顔料の理論収量を基準として、前記製造方法（２）の場合には、粗製顔料の実使用量を基準として、適当量の当該界面活性剤、好ましくは粗製顔料の質量換算１００部当たり、当該界面活性剤を０．５〜１２部を存在させて行う。このようにすることで、質量換算で有機顔料１００部当たり、当該界面活性剤０．５〜１２部である好適な有機顔料組成物を得ることが出来る。
【００３６】
本発明の製造方法によれば、予め得られた有機顔料に対して当該界面活性剤を添加する場合と異なり、粗製顔料から顔料への転移時に、常に粗製顔料の粒子間に当該界面活性剤分子が配置される、或いは粗製顔料の表面に当該界面活性剤分子が吸着される等の結果、顔料化に伴って刻々と変化する粒子表面状態のうちの、分子間水素結合に起因する凝集をも効果的に阻害することが出来るので好ましい。以下この方法について詳述する。
【００３７】
本発明の製造方法では、粗製顔料を製造する第１工程が、当該界面活性剤の存在下又は不存在下で行われる。
【００３８】
本発明の第１工程において粗製顔料を製造するとは、一種または二種以上の原料物質を化学反応させて粗製顔料の化学構造を形成することを意味する。粗製顔料には多くの種類がありその原料物質も多岐に亘るため、各々の粗製顔料の製造方法を例示することは出来ないが、それは当業者の常識に当たるものである。粗製顔料の種類に関しては、前記した有機顔料に対応する各々の粗製顔料がいずれも使用できる。中でも、粗製ベンツイミダゾロン系アゾ顔料を用いて本発明の製造方法に従って有機顔料組成物を製造すると、従来対比で、鮮明性、着色力及び透明性のいずれの点でも大きな改良効果が見られる。
【００３９】
本発明の製造方法（１）においては、当該界面活性剤の存在下に第１工程に当たる粗製顔料の製造が行われる。こうして第１工程で当該界面活性剤の存在下で公知慣用の製造方法に従って粗製顔料を製造すると、生成物は、当該界面活性剤と粗製顔料とを含む粗製顔料組成物となる。一方、本発明の製造方法（２）においては、当該界面活性剤の不存在下で第１工程に当たる粗製顔料の製造が行われる。従って、ここでの生成物は、当該界面活性剤を含まない粗製顔料であり、公知慣用の粗製顔料がそのまま使用できる。
【００４０】
本発明の製造方法（１）に従って、第１工程に当たる粗製顔料の製造を行いたければ、当該界面活性剤の存在下で公知慣用の製造方法に従って粗製顔料を製造すれば良い。以下、当該界面活性剤の不存在下で行う場合を例に、粗製キナクリドン顔料と粗製ベンツイミダゾロン系アゾ顔料の製造方法について詳述する。
【００４１】
粗製キナクリドン顔料は、２，５−ジアニリノテレフタル酸、ハロゲン原子またはメチル基を有する２，５−ジアニリノテレフタル酸、もしくは前記の混合物を原料として質量換算で原料の３〜６倍のポリリン酸を反応容器に仕込み、温度１１０〜１４０℃で１〜５時間攪拌することにより環化化合物を合成後、得られた環化化合物を質量換算でこの環化化合物の３〜１５倍相当量の大過剰の水もしくは無機酸の様な液媒体と混合して加水分解物を得る。次いで得られた加水分解物を濾過・洗浄し目的とする粗製キナクリドン顔料を得ることができる。この粗製キナクリドン顔料は、含水状態あるいは乾燥した状態で使用することができる。
【００４２】
尚、環化化合物を得るときの、ポリリン酸は公知慣用の方法で調整すればよいが、例えば８５％リン酸に無水リン酸を加えて攪拌することにより調整することができる。無機酸としては例えばリン酸や硫酸を使用することができる。環化化合物の加水分解法としては、液媒体の攪拌下に前記環化化合物を添加する方が望ましく、添加後は温度１０〜１８０℃で０．２５〜３時間攪拌することで加水分解物を得ることができる。このとき、添加する環化化合物と液媒体の温度差が大きいほど、より微細な粒子が得られ望ましい。得られた加水分解物の濾過・洗浄・乾燥は常法に従って行うことができる。
【００４３】
粗製ベンツイミダゾロン系アゾ顔料の場合には常法に従い、ベース成分を冷鉱酸水溶液中で亜硝酸ソーダと反応させることにより得たジアゾニウム塩と、アルカリ水溶液中に溶解させたカップラー成分とを、ジアゾカップリング反応させることにより得られる。この反応は通常ｐＨ４〜１３、温度−５〜６０℃の範囲でおこなわれ、ベース成分をカップラー成分中に添加しても、カップラー成分をベース成分中に添加しても、あるいは同時にベース成分とカップラー成分とを一定速度で反応させても良い。
【００４４】
このとき、必要に応じて反応ｐＨを一定に制御するための緩衝剤や表面処理剤を存在させることができる。緩衝剤はその種類、量は特に限定されないが、酢酸ナトリウム等を使用することができる。表面処理剤としては、例えばロジン類、界面活性剤等、公知の添加剤を使用することができる。粗製顔料を濾過しやすくするため、カップリング反応後の反応溶液を温度６０〜９５℃とし、１〜５時間保持することができる。こうして得られた粗製ベンツイミダソロン系アゾ顔料は、含水状態あるいは乾燥した状態で使用することができる。
【００４５】
尚、粗製キナクリドン顔料と粗製ベンツイミダゾロン系アゾ顔料以外のその他の粗製顔料は、従来公知の製法に従って製造された粗製顔料を使用することができる。
【００４６】
本発明の有機顔料組成物の製造方法においては、第１工程に引き続き、第１工程で得た粗製顔料を顔料化して有機顔料とする。
【００４７】
本発明の有機顔料組成物の製造方法の第２工程では、粗製顔料組成物または粗製顔料を顔料化して有機顔料組成物とする。本発明の製造方法（１）においては、当該界面活性剤の存在下に第１工程に当たる粗製顔料の製造が行われるから、この第２工程は当該界面活性剤の不存在下で顔料化を行うことができる。一方、本発明の製造方法（２）においては、当該界面活性剤の不存在下で第１工程に当たる粗製顔料の製造が行われるから、この第２工程は当該界面活性剤の存在下で顔料化が行われる。
【００４８】
ちなみに、従来技術に記載した特許文献７の方法は、本発明の有機顔料組成物の製造方法に照らすと製造方法（２）に相当し、第１工程を当該界面活性剤の不存在下で行い製造された粗製顔料に、当該界面活性剤の存在下で下記に説明する第２工程に当たる顔料化処理を行うことにより有機顔料組成物を得るものである。
【００４９】
この顔料化方法としては、従来公知のソルベントソルトミリング法（前者の方法という）やソルベント法（後者の方法という）を採用することができる。以下、当該界面活性剤の不存在下で行う場合を例に説明する。本発明の製造方法（２）に従って、第２工程に当たる粗製顔料の顔料化を行いたければ、当該界面活性剤の存在下で以下のような顔料化を行えば良い。
【００５０】
前者の方法は、一定量の粗製顔料を、質量換算で粗製顔料の３〜２０倍相当量の水溶性無機塩および粗製顔料の０．５〜１０倍相当量の水溶性有機溶剤の存在下に６０〜１２０℃で混練する方法である。水溶性無機塩としては、例えば塩化ナトリウム、硫酸ナトリウム等が挙げられ、水溶性有機溶剤としては、ジエチレングリコールやトリエチレングリコール等が挙げられる。この際の混練時間は特に制限されないが０．５〜８時間が望ましい。このようにしてソルベントソルトミリング法で得られた生成物は、例えば水または湯で洗浄後、必要に応じて乾燥等の工程を経て有機顔料組成物とすることができる。
【００５１】
後者の方法は、粗製顔料と粗製顔料よりも大過剰の体積の水及び／または有機溶剤とを混合して加熱することである。より具体的には、一定量の粗製顔料を、粗製顔料の質量換算３〜１５倍相当量の大過剰の水、有機溶剤もしくはその混合液中で８０〜１５０℃で攪拌する方法である。ここでの有機溶剤としては、例えばキシレン、２−ブタノール、ジメチルホルムアミド、Ｎ−メチル−２−ピロリドン、ジメチルスルホキシド、ジメチルイミダゾリジノン等が挙げられる。この際の攪拌時間は特に制限されないが、通常０．５〜１５時間が望ましい。有機溶剤には、有機顔料組成物の使用対象の適性にあわせて、酸、塩基、表面処理剤等を含有させることができる。このようにしてソルベント法で得られた生成物は、例えば濾過後、水または湯で洗浄し、必要に応じて乾燥等を行うことにより有機顔料組成物とすることができる。
【００５２】
従来の条件対比で本発明における顔料化の方法としては、ソルベントミリング法より低エネルギーで有機顔料組成物を得られる前記ソルベント法を採用することが好ましい。
【００５３】
こうして、当該界面活性剤の存在下に第１工程を行う製造方法（１）、当該界面活性剤の存在下に第２工程を行う製造方法（２）、或いは、当該界面活性剤の存在下に第１工程及び第２工程の両方を行う製造方法により、当該界面活性剤と有機顔料とを含む有機顔料組成物が得られる。
【００５４】
前記好適な方法を各々組み合わせた本発明の製造方法から得られた有機顔料組成物は、従来の製法から得られた有機顔料組成物に比べ、粒子径が小さく粒子間の結合力が弱い凝集物となるため、窒素吸着法によるＢＥＴ比表面積を大きくすることが出来るので好ましい。
【００５５】
本発明の製造方法から得られた有機顔料組成物の窒素吸着法によるＢＥＴ比表面積は、一般的には５０〜９０ｍ^２／ｇである。
【００５６】
尚、本発明における窒素吸着法におけるＢＥＴ比表面積は、日本工業規格（Ｊａｐａｎｅｓｅ　Ｉｎｄｕｓｔｒｉａｌ　Ｓｔａｎｄａｒｄ；ＪＩＳ）　Ｚ　８８３０−１９９０の附属書２（気体吸着による粉体の比表面積測定方法；試料の前処理；温度１２０℃、２０分、試料採取量；０．２５ｇ、吸着量の測定方法；１点法、窒素分圧；０．３）に従って測定できる。マイクロデータ株式会社製マイクロソープ４２３２ＩＩは、これに準拠した比表面積測定装置である。
【００５７】
本発明の顔料分散体は、本発明の製造方法から得られた有機顔料組成物と分散媒とを含んで成るものであり、これらを必須成分として混合することで調製することが出来る。この分散媒は液体でも固体でも良い。本発明の有機顔料組成物には、分散媒の必須成分として樹脂を含めることで顔料分散体とすることが出来る。この際の樹脂としては、熱可塑性樹脂が一般的である。
【００５８】
本発明の製造方法から得られた有機顔料組成物と熱可塑性樹脂とを含有する顔料分散体には、その性状により、固形の顔料分散体と、液状の顔料分散体が含まれる。本発明の顔料分散体は、例えば、有機顔料と当該界面活性剤とを含有する有機顔料組成物を、顔料分散用熱可塑性樹脂に分散させることにより供給される。
【００５９】
本発明の顔料分散体は、本発明の製造方法から得られた有機顔料組成物と熱可塑性樹脂のみからなる顔料分散体、例えばプラスチック着色用マスターバッチや静電荷像現像用カラートナーのためのマスターバッチ等だけでなく、さらに熱硬化性樹脂等の樹脂、溶剤、その他添加剤等を加えた顔料分散体、例えば平版印刷用インキ、グラビア印刷インキ、塗料、着色プラスチック成形品、静電荷像現像用カラートナー、カラーフィルター作製用レジストインキ等を包含する。
【００６０】
本発明の顔料分散体を製造する場合には、粉末顔料組成物と、固形熱可塑性樹脂とを後者樹脂の溶融温度以上にて混合する様にしても良い。
【００６１】
一般に含水状態の有機顔料組成物は、乾燥工程における顔料粒子間の凝集を防げるため、粉末状態より凝集が少なく、透明性・着色力を重視する用途に有利である。これは、顔料粒子間に存在する水の表面張力により乾燥時に顔料粒子間の凝集を促進させるためであり、そのため含水状態にある有機顔料組成物と、液状の熱可塑性樹脂や熱可塑性樹脂有機溶剤溶液とを水や溶媒の沸点未満で混合することにより、顔料粒子表面の水が直接樹脂や有機溶剤で置き換わり、より透明性・着色力にすぐれた顔料分散体を得ることができる。この場合、必要であれば、水や有機溶剤を適時除去する様にしてもよい。
【００６２】
したがって、本発明において顔料分散体を製造するに当たっては、本発明の製造方法から得られた有機顔料組成物と熱可塑性合成樹脂とを必須成分としてフラッシングすると、より分散性に優れ、結果的により透明性に優れた顔料分散体とすることが出来る。
【００６３】
ここで、フラッシングとは、含水状態の有機顔料組成物と熱可塑性樹脂とを必須成分として混合し、有機顔料組成物を水相から油相に転相した後、水を除去する工程を意味する。尚、この水の除去は、デカンテーションと加熱・真空吸引とを組み合わせて行うことが出来る。
【００６４】
また本発明で用いられる有機顔料組成物は、熱可塑性樹脂のみに分散させてもよいが、熱可塑性樹脂を必須成分として含有する印刷インキ用ビヒクルや塗料用ビヒクル等に分散させることも出来る。
【００６５】
熱可塑性樹脂としては、たとえばポリエステル樹脂、ポリアミド樹脂、スチレン樹脂、アクリル樹脂、ポリオレフィン、ポリアルキレンテレフタレートやポリ塩化ビニル樹脂等の樹脂が分散用樹脂として使用できる。
【００６６】
たとえば平版印刷用インキのビヒクルは、たとえばロジン変性フェノール樹脂、石油樹脂、アルキッド樹脂等の樹脂を２０〜５０（質量）％、アマニ油、桐油、大豆油等の動植物油を０〜３０（質量）％、ｎ−パラフィン、イソパラフィン、ナフテン、α−オレフィン、アロマティック等の溶剤を１０〜６０（質量）％、その他可溶化剤、ゲル化剤等の添加剤を数（質量）％の原料から製造される。
【００６７】
またグラビア印刷インキ、フレキソ印刷インキ用ビヒクルの場合は、たとえばロジン類、マレイン酸樹脂、ポリアミド樹脂、ビニル樹脂、環化ゴム、塩化ゴム、エチレン−酢酸ビニル共重合体樹脂、ウレタン樹脂、ポリエステル樹脂、アルキド樹脂、ニトロセルロース、酢酸セルロース等から選ばれる一種以上の樹脂を１０〜５０（質量）％、アルコール類、トルエン、ｎ−ヘキサン、酢酸エチル、セロソルブ、酢酸ブチルセロソルブ等の溶剤３０〜８０（質量）％の原料等から製造される。
【００６８】
塗料用のビヒクルでは、たとえばアルキド樹脂、エポキシ樹脂、アクリル樹脂、ポリウレタン樹脂、ポリエステル樹脂、メラミン樹脂、ユリア樹脂、水溶性樹脂等の樹脂２０〜８０（質量）％、炭化水素類、アルコール類、ケトン類、水等の溶剤１０〜６０（質量）％の原料等から製造される。
【００６９】
着色プラスチック成形品を得る場合には、たとえばポリエチレン、ポリプロピレン等のポリオレフィンやポリ塩化ビニル樹脂等の、射出成形やプレス成形等の熱成形用の熱可塑性樹脂（プラスチック）が分散用樹脂として使用される。尚、これらの樹脂を用いて得た本発明の顔料分散体は、必要な形状に成形することにより着色成形品とすることが出来る。
【００７０】
静電荷像現像用トナーを得る場合には、たとえばポリエステル樹脂、ポリアミド樹脂、スチレン樹脂、アクリル樹脂等の常温で固形の皮膜形成性の熱可塑性樹脂が分散用樹脂として使用される。後に詳述するが、これらの樹脂を用いて得た本発明の常温固形の顔料分散体は、必要な粒径の粒子状となる様に、粉砕、分級することにより静電荷像現像用トナーとすることが出来る。
【００７１】
これら顔料分散体は、必要に応じて、他の樹脂、ゴム、添加剤、顔料や染料等と混合され最終的な印刷インキ、塗料、着色プラスチック成形品、静電荷像現像用トナー、カラーフィルター等に調整され使用される。
【００７２】
顔料分散体を製造する際の、有機顔料組成物を熱可塑性樹脂に分散する分散機としては、たとえばディスパー、ホモミキサー、ビーズミル、二本ロール、三本ロール、常圧および加圧ニーダー、超音波分散機等の公知の分散機があげられるが、これらに限定されるものではない。
【００７３】
分散条件は、分散媒および分散機によって異なるため、分散温度や分散時間は問わないが、分散温度が室温〜３００℃、好ましくは室温〜２４０℃、分散時間は１分〜１２０時間、好ましくは３分〜７時間である。
【００７４】
顔料分散体中の有機顔料組成物の含有率は、特に制限されるものではなく、数〜５０（質量）％程度であるが、用途によって異なっており、最終製品中の本発明の有機顔料組成物分は、たとえば平版印刷インキでは１３〜２０（質量）％、グラビア印刷インキでは３〜２０（質量）％、塗料では０．３〜１５（質量）％、またプラスチックの着色用途では０．０１〜１（質量）％、静電荷像現像用トナーでは２〜１０（質量）％程度、カラーフィルター用途ではたとえばレジストインキとして使用される場合４〜７（質量）％程度である。
【００７５】
本発明の顔料分散体は、例えばペーストカラー、ドライカラーとして使用することが出来るが、それ自体を、前記熱成形用や静電荷像現像用トナーの結着樹脂として使用される未着色の熱可塑性樹脂の、着色用マスターバッチとして用いると、直接、熱可塑性樹脂の全量と均一に混合するのに比べて、より短時間により均一に着色された成形品や静電荷像現像用トナーを得ることができる。
【００７６】
有機顔料組成物と熱可塑性樹脂を含有する本発明の顔料分散体においては、有機顔料組成物の性能を最大限発揮させるため、前記した通り、フラッシング法による分散体の製造法が特に有効である。
【００７７】
特に顔料の透明性が要求される用途には、乾燥時に顔料粒子の強い凝集を引き起こしやすく、熱可塑性樹脂への分散性が低下しやすい粉末状態の有機顔料組成物と熱可塑性樹脂とを混合するよりも、含水状態の有機顔料組成物を熱可塑性樹脂とでフラッシングすることにより、品質のより優れた顔料分散体が得られる。
【００７８】
本発明の製造方法から得られた有機顔料組成物の、着色力だけでなく透明性に優れる着色媒体を与えるという特徴は、それから顔料分散体を調製した際に発揮され、特に、各色静電荷像現像用トナーを重ね合わせてカラー画像を形成するフルカラートナーの分野において、発色が良好で鮮明な画像が得られるという効果につながるものである。
【００７９】
本発明の製造方法から得られた有機顔料組成物および顔料分散体を構成成分として製造される静電荷像現像用トナーは、トナー中に磁性体を含有する１成分色磁性トナー（磁性一成分現像用カラートナー）、磁性体を含有しない非磁性１成分色カラートナー（非磁性一成分現像用カラートナー）、又は、キャリアーを混合した２成分色現像剤用カラートナー（二成分現像用カラートナー）として用いることができる。
【００８０】
１成分色磁性トナーは、通常使用されているものと同様に、例えば着色剤、結着樹脂、磁性粉、電荷制御剤（ＣＣＡ）や離型剤に代表されるその他添加剤等から構成出来る。
【００８１】
静電荷像現像用トナー中に占める有機顔料組成物の使用量は特に限定されないが、結着樹脂１００質量部に対し０．５〜２５質量部の割合で使用することが好ましく、着色剤自身の有する帯電性能を一層顕著ならしめる点から結着樹脂１００質量部に対し４〜１０質量部であることが更に好ましい。
【００８２】
静電荷像現像用トナーに用いられる結着樹脂としては、前記熱可塑性樹脂として例示した公知慣用のものがいずれも使用できるが、熱又は圧力の適用下で接着性を示す合成樹脂、天然樹脂、天然ゴム、合成ゴム、合成ワックス等がいずれも使用できる。
【００８３】
静電荷像現像用トナーに用いられる合成ワックスとしては、例えば、塩素化パラフィンワックス、パラフィンワックス、ポリプロピレンワックス、ＰＶＣ等が挙げられる。
【００８４】
また、前記の天然樹脂としては、例えばバルサム樹脂、ロジン、シェラック、コーバル等であり、これらの樹脂は後述するビニル樹脂、アクリル樹脂、アルキド樹脂、フェノール樹脂等から選ばれる１種又はそれ以上の樹脂で変性されていてもよい。
【００８５】
また、天然又は合成ゴム物質としては、例えば天然ゴム、塩素化ゴム、環化ゴム、ポリイソブチレンゴム、エチレン−プロピレンゴム、ポリブタジエンゴム、ブチルゴム、スチレン−ブタジエンゴム、アクリロニトリル−ブタジエンゴム、クロロプレンゴム、シリコンゴム、フッ素ゴム等が挙げられる。
【００８６】
静電荷像現像用トナーを調製する際に用いられる結着樹脂は、これらに限定されるものではなく、結着樹脂成分の２種以上が適宜混合されて用いられてもよい。
【００８７】
この結着樹脂としては、示差走査熱量計（ＤＳＣ）によるガラス転移温度４５〜８５℃、定荷重押出し形細管式レオメーター（高架式フローテスター；（株）島津製作所製、島津フローテスタＣＦＴ−Ｃ形。ピストン断面積１ｃｍ^２、シリンダ圧力０．９８ＭＰａ、ダイ長さ１ｍｍ、ダイ穴径１ｍｍ、測定開始温度５０℃、昇温速度６℃／ｍｉｎ、試料質量１．５ｇ）による溶融粘度が１×１０^５ポイズとなる温度が９５〜１７０℃であるものが好ましい。
【００８８】
尚、これら結着樹脂のうちでもスチレン樹脂、アクリル樹脂、ポリエステル樹脂及びエポキシ樹脂が、その透明性及び静電荷像現像用トナーの色相面から有利に使用できるが、特にポリエステル樹脂が好ましい。
【００８９】
静電荷像現像用トナーを調製する際に用いられる磁性粉は、特に限定されるものではないが、それ自身の色が再現された色に影響を及ぼしにくいものが好ましく使用でき、例えば、γ−酸化鉄、黄色γ−酸化鉄、フェライト等の酸化鉄；鉄、コバルト、ニッケルのような金属、或いはこれらの金属とアルミニウム、コバルト、銅、鉛、マグネシウム、錫、亜鉛のような金属との合金、ポリ−１，４−ビス（２，２，６，６，−テトラメチル−４−オキシル−４−ピペリジル−１−オキシル）ブタジエンポルフィリン金属錯体の様な有機磁性体及びそれらの混合物等が挙げられる。また、これらの中で特に色相の面から、黄色γ−酸化鉄の使用が好ましい。
【００９０】
これら磁性粉としては平均粒子径０．１〜１μｍのものが使用でき、帯電安定性及び色相の点から０．１〜０．５μｍのものを使用することが好ましい。また、これらを静電荷像現像用トナーに含有させる量としては、質量換算で結着樹脂１００部に対して３０〜１５０部で使用でき、帯電安定性及び色相の点から質量換算で結着樹脂１００部に対して４０〜１２０部が好ましい。
【００９１】
静電荷像現像用トナーを調製する際には、前記各成分のほかに必要に応じて静電荷像現像用トナーの熱特性、電気特性、物理特性等を調整する目的で各種の可塑剤、抵抗調整剤及び電荷制御剤を更に添加してもよい。
【００９２】
可塑剤としては、例えば、フタル酸ジブチル、フタル酸ジオクチル等が、抵抗調整剤としては酸化スズ、酸化鉛、酸化アンチモン等が、電荷制御剤としては四級アンモニウム塩、ピリジニウム塩、含金属染料等が夫々挙げられる。
【００９３】
更に、本発明においては静電荷像現像用トナー粒子の製造後、これにＴｉＯ_２、Ａｌ_２Ｏ_３、ＳｉＯ_２等の微粉末を添加してトナーの流動性改良を図ったり、ステアリン酸亜鉛、フタル酸等を添加して感光体の劣化防止を図っても良い。
【００９４】
本発明による有機顔料組成物および顔料分散体から静電荷像現像用トナーを調製する際には、特定の製造方法に依らず極めて一般的な製造方法を採用出来る。例えば、前記の各成分を押し出し機、２本ロール、３本ロール又は加熱ニーダー等の混練手段により混合し、本発明の有機顔料組成物および顔料分散体を含む混練物を得て、これを冷却後、ジェットミル等の粉砕機で撹拌し、風力分級機により分級して、粒子状となすことにより、本発明の有機顔料組成物および顔料分散体から、目的とする粉体の静電荷像現像用トナーが得られる。
【００９５】
本発明の製造方法で得られた有機顔料組成物を、従来より容易に分散媒への分散が可能であるという特徴を活かして、転相乳化法や酸析法等の湿式法による静電荷像現像用トナーに適用することも出来る。これらの方法で得られた静電荷像現像用トナーは、有機顔料が結着樹脂に被覆された球形の複合粒子状となるため、前記した乾式法よりも優れた特性を有する。
【００９６】
また、熱可塑性樹脂として前記した様な静電荷像現像用トナーの調製に適した結着樹脂を用い、有機顔料組成物を高濃度で含む本発明の顔料分散体のマスターバッチを予め製造しておき、前記したのと同一又は前記したのと異なるトナー用結着樹脂で希釈する様にして混練して、所定の有機顔料組成物濃度の得る様にすると、マスターバッチを介しないで製造する場合よりは、より透明性に優れた画像が得られる静電荷像現像用トナーを製造することが出来る。
【００９７】
さらに、前記フラッシングとマスターバッチの手法を組み合わせることにより、同一樹脂を用いた場合における対比においては、最も透明性に優れ、発色が良好で鮮明な画像が得られる静電荷像現像用トナーを製造することが出来る。
【００９８】
尚、本発明で言う静電荷像現像用カラートナーは、有機顔料組成物が前記結着樹脂に分散した粒子状の分散体であるが、その静電荷像現像用トナー粒子の平均粒子径は３〜１５μｍであることが好ましい。
【００９９】
２成分色現像剤用カラートナーとして用いる場合も１成分色磁性トナーに使用されているものと同じ着色剤、結着樹脂、前記した様なその他添加剤等を使用できる。
【０１００】
更に、静電荷像現像用トナーに用いられるキャリアーとしては、例えば、鉄粉、ニッケル粉、フェライト粉、ガラスビーズ、或いはこれらを芯材とし表面にスチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体、アクリル酸エステル重合体、メタクリル酸エステル重合体、シリコーン樹脂、ポリアミド樹脂等又はこれらの樹脂の混合物をコーティングしたものが使用でき、その粒子径は５０〜３００μｍの範囲にあるものが好ましい。
【０１０１】
２成分色現像剤用カラートナーは、これらのキヤリアー粒子と本発明のカラートナーとを水平円筒形、Ｖ形等の容器回転型混合機で摩擦混合することによって得ることができる。
【０１０２】
また、キャリアーと静電荷像現像用トナーとの混合比は適切な画像濃度を得るために通常、質量換算でキャリアー１００部に対して静電荷像現像用トナー２〜１０部、好ましくは４〜６部の範囲で使用できる。
【０１０３】
【実施例】
以下、製造例、実施例および比較例を挙げ、本発明を詳細に説明する。なお、例中の部および％は質量基準である。
【０１０４】
実施例１（顔料化時のみに当該界面活性剤を含ませる実験例）
〈第１工程〉
１，２−ビス（２−アミノフェノキシ）−エタン２７１．９部を、水２７００部に攪拌分散しながら、３５％塩酸６４５．９部を加えた。１時間攪拌後、氷を加えて温度を０〜５℃に調整し、４０％亜硝酸ソーダ水溶液４０４．２ｇを加え、ジアゾ化反応を行った。１時間以上攪拌後、過剰の亜硝酸塩を除去するため１１８．１部の１０％スルファミン酸水溶液を加えて３０分以上攪拌し、さらに２７部の活性炭を加え３０分以上攪拌し、ビスジアゾニウム塩溶液の調製を行った。
【０１０５】
一方、５−アセトアセチルアミノ−ベンズイミダゾロン５３９．２部を水４０００部に分散後、２５％水酸化ナトリウム水溶液７１２．９部を加えて溶解させ、カップラー成分を得た。ジアゾ成分およびカップラー成分は、水および氷を加えてそれぞれ液量を８１００部および５４００部に調製した。
【０１０６】
９０％酢酸３５．８部を水８１００部に加えた後、この溶液の温度を４０℃、ｐＨを５．０に調製した。カップリングのため、カップラー成分の添加調整によりｐＨを８．０にあわせながら、同時にジアゾ成分を一定速度で加えた。カップリング中温度が４０℃、またｐＨ８．０を維持するよう適時氷または５％水酸化ナトリウム水溶液を添加しながら、カップリングを約３時間で終了した。未反応のジアゾ成分が反応溶液中に含まれていないことを確認後、９０℃に加熱し１時間保持した。次いで、濾過、水洗を行い、含水状態の粗製ベンツイミダゾロン系アゾ顔料を得た。
【０１０７】
〈第２工程〉
攪拌装置付きの加圧可能な反応容器に、上記の含水状態の粗製ベンツイミダゾロン系アゾ顔料の１３１．１部（固形分換算２０部）、アンヒトール（登録商標）８６Ｂ〔花王株式会社製ステアリルベタインの含水ペースト。前記一般式（１）において、Ｒ^２及びＲ^３がいずれもメチル基であり、Ｒ^１がステアリル基である界面活性剤を主成分とする。固形分２６％。〕の１．５８部を仕込んだ。水を加えて容器内の質量を６００部に調整後、攪拌下に約２時間かけて常温から１４０℃まで昇温し、５時間保持後、室温まで冷却して内容物を取り出した。この内容物を濾過洗浄後、９０℃で１２時間以上乾燥を行った。乾燥後の固形物をジューサーミキサーで粉砕し、前記アンヒトール（登録商標）８６Ｂとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１０８】
実施例２（粗製顔料製造時のみに当該界面活性剤を含ませる実験例）
〈第１工程〉
１，２−ビス（２−アミノフェノキシ）−エタン２７１．９部を、水２７００部に攪拌分散しながら、３５％塩酸６４５．９部を加えた。１時間攪拌後、氷を加えて温度を０〜５℃に調整し、４０％亜硝酸ソーダ水溶液４０４．２ｇを加え、ジアゾ化反応を行った。１時間以上攪拌後、過剰の亜硝酸塩を除去するため１１８．１部の１０％スルファミン酸水溶液を加えて３０分以上攪拌し、さらに２７部の活性炭を加え３０分以上攪拌し、ビスジアゾニウム塩溶液の調製を行った。
【０１０９】
一方、５−アセトアセチルアミノ−ベンズイミダゾロン５５７．４部を水４０００部に分散後、２５％水酸化ナトリウム水溶液７１２．９部を加えて溶解させ、カップラー成分を得た。ジアゾ成分およびカップラー成分は、水および氷を加えてそれぞれ液量を８１００部および５４００部に調製した。
【０１１０】
９０％酢酸３５．８部を水８１００部に加えた後、この溶液の温度を４０℃、ｐＨを５．０に調整する。カップリングのため、カップラー成分の添加調整によりｐＨを８．０にあわせた後、１５７．４部のアンヒトール（登録商標）８６Ｂを添加し、カップラー成分と同時にジアゾ成分を一定速度で加えた。カップリング中温度が４０℃、またｐＨ８．０を維持するよう適時氷または５％水酸化ナトリウム水溶液を添加しながら、カップリングを約３時間で終了した。
【０１１１】
未反応のジアゾ成分が反応溶液中に含まれていないことを確認後、９０℃に加熱し１時間保持した。次いで、濾過、水洗を行い、含水状態のアンヒトール（登録商標）８６Ｂと粗製ベンツイミダゾロン系アゾ顔料とを含む粗製顔料組成物を得た。
【０１１２】
〈第２工程〉
攪拌装置付きの加圧可能な反応容器に、上記の含水状態の粗製顔料組成物の１３３．７部（固形分換算２０部）を仕込んだ。水を加えて容器内の質量を６００部に調整後、攪拌下に約２時間かけて常温から１４０℃まで昇温し、５時間保持後、室温まで冷却して内容物を取り出した。この内容物を濾過洗浄後、９０℃で１２時間以上乾燥を行った。乾燥後の固形物をジューサーミキサーで粉砕し、前記アンヒトール（登録商標）８６Ｂとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１３】
比較例１（ベタイン型両性界面活性剤を含ませない実験例）
アンヒトール（登録商標）８６Ｂを用いず、含水状態の粗製ベンツイミダゾロン顔料１３１．１部（固形分換算２０部）だけを用いる以外は実施例１と同様の操作を行い、界面活性剤を含まないベンツイミダゾロン系アゾ顔料を得た。
【０１１４】
比較例２
１５７．４部のアンヒトール（登録商標）８６Ｂの代わりに１３６．４部のアンヒトール（登録商標）５５ＡＢ〔花王株式会社製コカミドプロピルベタインの含水ペースト。前記一般式（１）に含まれない構造のベタイン型両性界面活性剤。固形分３０％。〕を添加した以外は実施例２の第１工程と同様にして、前記アンヒトール（登録商標）５５ＡＢと粗製ベンツイミダゾロン系アゾ顔料とを含む含水状態の粗製顔料組成物を得た。
次いで、この粗製顔料組成物６６．３部（固形分換算２０部）を仕込んで加熱攪拌を行った以外は実施例２の第２工程と同様にして、前記アンヒトール（登録商標）５５ＡＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１５】
比較例３
１５７．４部のアンヒトール（登録商標）８６Ｂの代わりに１１６．９部の　のアンヒトール（登録商標）２０Ｎ〔花王株式会社製のラウリルジメチルアミンオキサイド型界面活性剤。前記一般式（１）に含まれない構造の界面活性剤。固形分３５％。〕を添加した以外は実施例２の第１工程と同様にして、前記アンヒトール（登録商標）２０Ｎと粗製ベンツイミダゾロン系アゾ顔料とを含む含水状態の粗製顔料組成物を得た。
次いで、この粗製顔料組成物８２．３部（固形分換算２０部）を仕込んで加熱攪拌を行った以外は実施例２の第２工程と同様にして、前記アンヒトール（登録商標）２０Ｎとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１６】
比較例４
１５７．４部のアンヒトール（登録商標）８６Ｂの代わりに１３６．４部のアンヒトール（登録商標）２０ＨＤ〔花王株式会社製のラウリルヒドロキシスルホベタイン。前記一般式（１）に含まれない構造のベタイン型界面活性剤。固形分３０％。〕を添加した以外は実施例２の第１工程と同様にして、前記アンヒトール（登録商標）２０ＨＤと粗製ベンツイミダゾロン系アゾ顔料とを含む含水状態の粗製顔料組成物を得た。
次いで、この粗製顔料組成物７７．３部（固形分換算２０部）を仕込んで加熱攪拌を行った以外は実施例２の第２工程と同様にして、前記アンヒトール（登録商標）２０ＨＤとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１７】
比較例５
１５７．４部のアンヒトール（登録商標）８６Ｂの代わりに１０２．３部のアンヒトール（登録商標）２０ＹＢ〔花王株式会社製の２−アルキル−Ｎ−カルボキシメチル−Ｎ−ヒドロキシエチルイミダゾリニウムベタイン。前記一般式（１）に含まれない構造の界面活性剤。固形分４０％。〕を添加した以外は実施例２の第１工程と同様にして、前記アンヒトール（登録商標）２０ＹＢと粗製ベンツイミダゾロン系アゾ顔料とを含む含水状態の粗製顔料組成物を得た。
次いで、この粗製顔料組成物７５．８部（固形分換算２０部）を仕込んで加熱攪拌を行った以外は実施例２の第２工程と同様にして、前記アンヒトール（登録商標）２０ＹＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１８】
比較例６
１５７．４部のアンヒトール（登録商標）８６Ｂの代わりに１３６．４部のアンヒトール（登録商標）２０ＡＢ〔花王株式会社製のラウリン酸アミドプロピルベタイン。前記一般式（１）に含まれない構造のベタイン型界面活性剤。固形分３０％。〕を添加した以外は実施例２の第１工程と同様にして、前記アンヒトール（登録商標）２０ＡＢと粗製ベンツイミダゾロン系アゾ顔料とを含む含水状態の粗製顔料組成物を得た。
次いで、この粗製顔料組成物７８．１部（固形分換算２０部）を仕込んで加熱攪拌を行った以外は実施例２の第２工程と同様にして、前記アンヒトール（登録商標）２０ＡＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１１９】
比較例７（特許文献７に対応する実験例）
アンヒトール（登録商標）８６Ｂの１．５８部のかわりに、アンヒトール（登録商標）５５ＡＢの１．３７部を使用した以外は実施例１と同様にして、前記アンヒトール（登録商標）５５ＡＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１２０】
比較例８
アンヒトール（登録商標）８６Ｂの１．５８部のかわりに、アンヒトール（登録商標）２０Ｎの１．１７部を使用した以外は実施例１と同様にして、前記アンヒトール（登録商標）２０Ｎとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１２１】
比較例９（特許文献７に対応する実験例）
アンヒトール（登録商標）８６Ｂの１．５８部のかわりに、アンヒトール（登録商標）２０ＨＤの１．３７部を使用した以外は実施例１と同様にして、前記アンヒトール（登録商標）２０ＨＤとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１２２】
比較例１０（特許文献７に対応する実験例）
アンヒトール（登録商標）８６Ｂの１．５８部のかわりに、アンヒトール（登録商標）２０ＹＢの１．０３部を使用した以外は実施例１と同様にして、前記アンヒトール（登録商標）２０ＹＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
比較例１１（特許文献７に対応する実験例）
アンヒトール（登録商標）８６Ｂの１．５８部のかわりに、アンヒトール（登録商標）２０ＡＢの１．３７部を使用した以外は実施例１と同様にして、前記アンヒトール（登録商標）２０ＡＢとベンツイミダゾロン系アゾ顔料とを含む有機顔料組成物を得た。
【０１２３】
尚、比較例で用いられた各種界面活性剤は以下の通りである。
【０１２４】
アンヒトール（登録商標）５５ＡＢ（下記一般式でＲ＝炭素原子数１１及び１３のアルキル基である化合物を主成分とする）及び同２０ＡＢ（下記一般式でＲ＝炭素原子数１１のアルキル基である化合物を主成分とする）
【０１２５】
【化３】

【０１２６】
アンヒトール（登録商標）２０Ｎ（下記一般式でＲ＝炭素原子数１２のアルキル基である化合物を主成分とする）
【０１２７】
【化４】

【０１２８】
アンヒトール（登録商標）２０ＨＤ（下記一般式でＲ＝炭素原子数１２のアルキル基である化合物を主成分とする）
【０１２９】
【化５】

【０１３０】
アンヒトール（登録商標）２０ＹＢ（下記一般式でＲ＝炭素原子数１１及び１３のアルキル基である化合物を主成分とする）
【０１３１】
【化６】

【０１３２】
評価方法
平版印刷用インキ試験
実施例１〜２、比較例２〜１１で得られた各有機顔料組成物、比較例１で得られた有機顔料およびＭＧ−６３（大日本インキ化学工業（株）社製の平版印刷インキ用ワニス）を下記の組成で混合した後、フーバーマーラーを使用して、１５０ｌｂｓの荷重下で１００回転の分散を３回繰り返して評価用のオフセットインキを調整した。
各有機顔料組成物または有機顔料　　　　０．４部
ＭＧ−６３　　　　　　　　　　　　　　１．６部
【０１３３】
着色力は、前記で調整したオフセットインキを１部、銅フタロシアニンブルー顔料、チタンホワイト顔料およびワニスからなる青色基準インキ５部をフーバーマーラーで、加重１００ポンド下、１００回転×３回練肉して調整した緑色インキをアート紙上に展色して、実施例１から得られた展色板を標準として、目視判定７段階〔１（着色力小）＞＞＞７（着色力大）〕で判定した。
【０１３４】
透明性は、オフセットインキをアート紙に展色（ドローダウン）して、評価した。実施例１で得た有機顔料組成物を用いた展色板を標準とした相対評価により、透明性を目視判定７段階〔１（透明性小）＞＞＞７（透明性大）〕で判定した。
【０１３５】
鮮明性を定量化する方法として、インキを展色して得た展色板を分光測色計で測色して彩度（Ｃ＊値）の大きさを求めた。ミノルタ（株）製分光測色計ＣＭ−２６００ｄを用いて測定を行った。
【０１３６】
実施例１〜２及び比較例１〜１１について得られた評価結果を表１にまとめて示した。
【０１３７】
【表１】
表　１

【０１３８】
第２工程においてベタイン型両性界面活性剤を用いて製造した有機顔料組成物に関する、実施例１と比較例２との対比からわかる様に、ベタイン型両性界面活性剤であっても、本発明で用いる一般式（１）で表される界面活性剤を用いたものは、着色力、透明性及び彩度のいずれにも優れているのに対し、一般式（１）に包含されない（しかし、特許文献７において最も優れていると記載されている）ベタイン型界面活性剤を用いたものでは、着色力と彩度が劣っていることが明らかである。尚、実施例１の有機顔料組成物は、界面活性剤未処理の有機顔料である比較例１に対して着色力が改善されるのに対し、この比較例２の有機顔料組成物は、実施例１での傾向とは逆に、着色力が低下する。
【０１３９】
また、第２工程においてベタイン型両性界面活性剤を用いて製造した有機顔料組成物に関する実施例１と、第１工程においてベタイン型両性界面活性剤を用いて製造した有機顔料組成物に関する実施例２との対比からわかる様に、同一のベタイン型界面活性剤を用いる場合には、第１工程においてベタイン型両性界面活性剤を用いて製造した有機顔料組成物の方が、着色力と透明性の改善が著しく、着色力、透明性、彩度のいずれにおいても優れていることが明らかである。
【０１４０】
さらに比較例７と比較例２との対比からわかる様に、一般式（１）に包含されないベタイン型界面活性剤を用いて製造した有機顔料組成物の間では、一般式（１）で表されるベタイン型界面活性剤を用いて製造した有機顔料組成物に関する、この実施例１と２との間での着色力の改善効果は見られないことから、本発明における一般式（１）で表されるベタイン型界面活性剤は、有機顔料の製造方法において、その他の界面活性剤からは予想できない特異的な効果を発現することが明らかである。
【０１４１】
グラビア印刷用インキ試験
実施例１〜２、比較例２〜４で得られた有機顔料組成物及び比較例１で得られた有機顔料を下記の配合で２５０ｍｌの容器に秤量し、ペイントコンディショナーで１２０分間練肉して黄色ウレタングラビア系インキを作製した。
トルエン　　　　　　　　　　　　　　１８．３部
メチルエチルケトン　　　　　　　　１０．１部
ウレタン樹脂系ワニス　　　　　　　　１９．８部
各有機顔料組成物または有機顔料　　１１．８部
スチールビーズ　　　　　　　　　１８０　　部
【０１４２】
作製したウレタングラビア系インキの作製直後のインキ粘度を、Ｂ型粘度計を使用して２０℃、回転数１２ｒ．ｐ．ｍ．、６０ｒ．ｐ．ｍ．にて測定した。また作製したウレタングラビア系インキをポリエステルフィルム上にバーコータ（Ｗｅｂｓｔａｒ　Ｎｏ．６）にて展色し、塗膜を測色計Ｄ１８６型（グレタグ社製）を用いて測色した。ＹフィルターでのＤｅｎｓｉｔｙ値を測定して着色力とし、ＢフィルターでのＤｅｎｓｉｔｙ値を測定して透明性とした。また同様に、ヘイズ−グロス　リフレクトメーター（ビック−ガードナー社製）で６０°光沢を測定した。結果を、比較例１を標準とした場合の相対値として、表２に示す。このとき粘度は相対値の値が小さいほど、また着色力、透明性および光沢は値が大きいほど望ましい。実施例１〜２における彩度は、比較例１〜４のそれより優れていた。
【０１４３】
【表２】
表　２

【０１４４】
【発明の効果】
本発明に有機顔料組成物の製造方法は、粗製顔料を製造する第１工程と、この第１工程で得られた粗製顔料を顔料化して有機顔料とする第２工程とからなり、前記第１工程及び／または第２工程をベタイン型両性界面活性剤の存在下で行う、ベタイン型両性界面活性剤と有機顔料とを含有する有機顔料組成物の製造方法において、前記ベタイン型両性界面活性剤として、特定一般式（１）で表されるものを用いるので、それを第１工程、第２工程のいずれで用いても、従来のベタイン型両性界面活性剤を用いる場合に比べて、微細であり凝集も少ない。
従って、被着色媒体である分散媒中における有機顔料組成物の分散性に優れ、着色媒体である顔料分散体の着色力、透明性及び鮮明性を、いずれもより優れたものとすることが出来るという格別顕著な効果を奏する。
【０１４５】
特に、本発明の顔料分散体は、印刷インキ、塗料、着色プラスチック成形品、静電荷像現像用トナー、カラーフィルター用レジストインキ等に使用した場合、より優れた着色力を付与することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an organic pigment composition useful for coloring various applications, particularly inks, paints, plastics, color toners, color filters, and the like, and a pigment dispersion.
[0002]
[Prior art]
Organic pigments have characteristics such as higher coloring power and sharpness than inorganic pigments, and are widely used as useful coloring agents in various applications such as inks, paints, plastics, color toners, and color filters. As a feature of the organic pigment, a dye is used in a state of being dispersed in a medium in a molecular state, whereas a dye is used by being dispersed in a medium in the form of crystalline particles. Therefore, organic pigments are superior in fastness to dyes. It is known that hydrogen bonds in the chemical structure of organic pigments, particularly intermolecular hydrogen bonds, contribute strongly to the development of the excellent robustness.
[0003]
Such an organic pigment generally has no suitability as a colorant immediately after synthesis from a raw material (immediately after the first step of producing a crude pigment, which will be described in detail later). This is because the organic pigment immediately after synthesis has a very fine and strongly aggregated particle size, or has a very large crystal particle size, and therefore has sufficient performance as an organic pigment for colorant applications. This is because the diameter deviates from the appropriate particle size.
[0004]
Therefore, these organic pigments having insufficient suitability as colorants are referred to in the art as crude pigments, crude pigments, crude or prepigments, and the like. The specific surface area of such a substance called a crude pigment measured by a BET specific surface area measurement method by a nitrogen adsorption method usually takes a lower value than in a form used as an organic pigment, and was used as it is as an organic pigment. In such a case, it is impossible to disperse an aggregate of fine particles or giant crystal particles forming a crude pigment in a dispersion medium to disperse and refine the particles to an optimum particle size as a colorant. Therefore, for example, a dispersion produced from a crude pigment is inferior in sharpness, tinting strength, and the like, and the crude pigment is usually not suitable for use as a coloring agent.
[0005]
In order to solve these problems, the crude pigment requires some post-treatment to be used as an organic pigment, and the crude pigment is subjected to a heat treatment in a liquid medium different from that in which the pigment was produced, thereby obtaining a pigment crystal. In general, a method of loosening a coagulated state by increasing the size of a large crystal and using a mechanical dispersing force such as a kneader or a ball mill together with a dispersing aid to refine a giant crystal is generally used. These post-treatments are commonly referred to as "pigmentation".
[0006]
That is, an organic pigment is generally produced by a production method comprising a first step of producing a crude pigment and a second step of converting the crude pigment obtained in the first step into a pigment to produce an organic pigment. I have.
[0007]
As means for pigmentation in the second step of pigmenting a crude pigment into an organic pigment, for example, the following Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 6 Literatures such as Literature 7 are known.
[0008]
These include pulverizing the crude pigment with a solid grinding aid and a halogen alcohol or cyano alcohol, heating the crude pigment in high-temperature water, pulverizing the crude pigment with a solid grinding aid and a chlorinated solvent, and then tetrachloroethylene or the like. Stir in an aqueous emulsion, heat the crude pigment from neutral to acidic containing benzoic acid and inorganic salt, or use the crude pigment as alkaline earth metal hydroxide, inorganic ammonium salt, alkali-soluble aromatic compound or amino acid. Such as dry pulverization in the presence of a pulverizing auxiliary such as described above, or heating a crude pigment with an aromatic compound having a water-soluble group at a high temperature.
[0009]
The particle size of the organic pigment obtained through such pigmentation affects various suitability of a dispersion using the organic pigment.For example, in the suitability for use in a printing ink, sharpness, transparency, It is widely known that the finer the particle size of the organic pigment, the higher the transparency and coloring power of the colored image tend to be improved, in relation to the properties, coloring power, hue, fluidity and the like. For this reason, if the particle size of the organic pigment is unnecessarily increased in order to loosen the aggregation of the organic pigment, for example, when used in a printing ink, the transparency and coloring power of the colored image are lost. , The transparency and the color development are reduced. In addition, when micronizing from a giant crystal, not only a large amount of energy is required, but also it is often difficult to miniaturize the organic pigment to a particle diameter required for required suitability. These problems have not yet been sufficiently solved in the known documents as mentioned above.
[0010]
The technique described in Patent Literature 7 is an organic pigment composition which is prepared by heat-treating a crude pigment produced in advance in a liquid medium containing a betaine-type amphoteric surfactant represented by the specific general formula (I). Is a manufacturing method. Here, carboxybetaine-type and 2-alkylimidazoline-derived amphoteric surfactants are used as betaine-type amphoteric surfactants. This method is useful to some extent as a method for enlarging the pigment crystals to loosen the aggregation state. However, since the betaine-type amphoteric surfactant used therein has a specific structure, there is a disadvantage that the coloring power of the colored image is still insufficient. Incidentally, the amphoteric surfactant represented by the specific general formula (II) is not a betaine-type amphoteric surfactant.
[0011]
Further, as a means for solving these problems, the production of the crude pigment is carried out in the presence of an appropriate treating agent in the first step, which is the production of the crude pigment, instead of the second step relating to the pigmentation. A method for improving the suitability such as coloring power of a colored image with an organic pigment by loosening the aggregation state of the pigment particles and subsequently performing the pigmentation in the second step to produce an organic pigment composition containing the treatment agent. Are known.
[0012]
However, depending on the type of the treating agent, these improvement effects are not sufficiently obtained, and the presence of the treating agent hinders the reaction during the production of the crude pigment. Then, even if the second step is performed subsequently, the resulting colored image obtained from the organic pigment composition containing the treating agent may cause hue stain (decrease in sharpness). According to the findings of the present inventors, a betaine-type amphoteric surfactant as described in Patent Document 7 is used to produce a crude pigment composition in the first step which is the production of a crude pigment. It is known that when the organic pigment composition is manufactured by performing the pigmentation in the second step successively, the above-described hue stain occurs in the colored image. It has been found that a similar hue stain occurs even with a non-betaine type amphoteric surfactant represented by the specific general formula (II) in Patent Document 7.
[0013]
[Patent Document 1]
JP-B-37-16166 (page 2, right column, lines 23-29, etc.)
[Patent Document 2]
JP-A-57-141457 (page 1, left column, lines 4 to 12)
[Patent Document 3]
JP-A-56-22356 (page 1, left column, line 5 to right column, line 7)
[Patent Document 4]
JP-A-56-67370 (page 1, left column, lines 4 to 10, etc.)
[Patent Document 5]
JP-A-1-193366 (page 1, left column, line 3 to same page, right column, line 16)
[Patent Document 6]
JP-A-8-295815 (page 2, column 1, lines 1-33, etc.)
[Patent Document 7]
JP-A-11-302554 (page 1, column 1, line 1 to page 2, column 22, line 22 etc.)
[0014]
[Problems to be solved by the invention]
The present invention relates to a betaine-type amphoteric surfactant having a specific chemical structure which is not specifically specified among the number of betaine-type amphoteric surfactants included in the specific general formula (I) described in Patent Document 7. By selecting only a surfactant and using the same in the first step and / or the second step as a process for producing an organic pigment to produce an organic pigment composition, a medium to be colored as a dispersion medium ( It is an object of the present invention to provide a method for producing an organic pigment composition capable of coloring a medium to be colored with good coloring power and good transparency while maintaining sharpness. Another object of the present invention is to provide a pigment dispersion having both excellent clarity, excellent coloring power, and excellent transparency.
[0015]
The problem to be solved by the present invention is mainly to produce a crude pigment in the presence of a betaine-type amphoteric surfactant having a chemical structure different from those commonly used in the related art, and to convert the crude pigment into an organic pigment. A composition is obtained or a crude pigment is produced in the absence of a betaine-type amphoteric surfactant, and the crude pigment is pigmentated in the presence of a betaine-type amphoteric surfactant having a specific chemical structure to form an organic pigment composition. By obtaining an organic pigment composition manufactured by pigmentation in the presence of a conventionally used betaine-type amphoteric surfactant, excellent sharpness and excellent coloring power and excellent transparency could not be achieved. An object of the present invention is to obtain an organic pigment composition that can easily obtain a pigment dispersion that is a colored medium (hereinafter, referred to as a coloring medium) having both properties.
[0016]
[Means for Solving the Problems]
As a result of intensive research, the present inventors have selected only those having a specific chemical structure from betaine-type amphoteric surfactants, and produced an organic pigment in the presence of the same. It has been found that an organic pigment composition that can be dispersed with less aggregation is obtained, and as a result, a pigment dispersion that is a coloring medium having both excellent clarity, excellent coloring power, and excellent transparency can be obtained. Was completed.
[0017]
That is, the present invention comprises a first step of producing a crude pigment, and a second step of converting the crude pigment obtained in the first step into a pigment to produce an organic pigment, wherein the first step and / or the second step In the presence of a betaine-type amphoteric surfactant, a method for producing an organic pigment composition containing a betaine-type amphoteric surfactant and an organic pigment, wherein the betaine-type amphoteric surfactant is represented by the following general formula (1): A method for producing an organic pigment composition containing a betaine-type amphoteric surfactant and an organic pigment, characterized by using a betaine-type amphoteric surfactant represented by the formula, and an organic pigment composition obtained by the production method A pigment dispersion comprising the substance and a dispersion medium. Hereinafter, the betaine-type amphoteric surfactant represented by the following general formula (1) is referred to as the surfactant.
[0018]
Embedded image
General formula (1)

[0019]
[In addition, in the general formula (1), R ¹ Is an aliphatic hydrocarbon group having 8 to 24 carbon atoms,
R ² And R ³ Is a hydrogen atom or a methyl group, which may be the same or different. ]
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for producing an organic pigment composition of the present invention comprises a first step of producing a crude pigment, and a second step of pigmentating the crude pigment obtained in the first step to obtain an organic pigment. This is a method for producing an organic pigment composition containing the surfactant and an organic pigment, wherein the step and / or the second step is performed in the presence of the surfactant.
[0021]
The organic pigment composition obtained by the production method of the present invention contains the surfactant and the organic pigment.
[0022]
The organic pigment in the present invention is a known and commonly used organic pigment, but is preferably an intermediate or higher pigment. Such intermediate or higher pigments include quinacridone pigments, diketopyrrolopyrrole pigments, benzimidazolone azo pigments, perylene pigments, perinone pigments, dioxazine pigments, isoindolinone pigments, isoindoline pigments, thioindigo pigments, quinophthalone pigments, anthra One or more organic pigments selected from the group consisting of quinone pigments are included. Above all, in the case of a benzimidazolone-based azo pigment, an organic pigment composition having particularly excellent sharpness, coloring power and transparency can be obtained.
[0023]
As the surfactant in the present invention, any of the known and commonly used surfactants corresponding to the general formula (1) can be used. R in the general formula (1) ² And R ³ Is a hydrogen atom or a methyl group, which may be the same or different. R ² And R ³ Means a hydrogen atom, a combination of a hydrogen atom and a methyl group, and all three types include a methyl group. R ¹ Is an aliphatic hydrocarbon group having 8 to 24 carbon atoms, for example, a hydrocarbon group which may contain 1 to 5 unsaturated double bonds or unsaturated triple bonds.
[0024]
The most common alkyldimethylaminoacetic acid betaine among the surfactants is represented by R in the general formula (1). ² And R ³ Are all methyl group substances.
[0025]
Examples of the surfactant include betaine octylaminoacetate, betaine octyldimethylaminoacetate, betaine decyldimethylaminoacetate, betaine laurylaminoacetate, betaine lauryldimethylaminoacetate, betaine stearylaminoacetate, betaine stearyldimethylaminoacetate, and eicosyldimethyl. N-mono long chain alkyl betaine type amphoteric surfactants such as betaine aminoacetate and tetracosyldimethylaminoacetate betaine, N-mono long chain alkyl monomethyl betaine type amphoteric surfactant, N-mono long chain alkyldimethyl betaine amphoteric surfactant Surfactants.
[0026]
The surfactant is represented by R in the general formula (1). ¹ The higher the bulk (the higher the molecular weight), the higher the dispersion stability of the obtained organic pigment composition in the dispersion medium, but conversely, in the crude pigment production process described in detail below, the ability to refine the crude pigment is increased. It tends to be smaller. Therefore, it is desirable to select and use an appropriate surfactant in accordance with the crude pigment to be used, the dispersion medium used for preparing the pigment dispersion, and the use of the pigment dispersion.
[0027]
The technical effect when the surfactant is used varies depending on the type of the organic pigment and the dispersion medium. ¹ When the number of carbon atoms is 12 or more, the effect of stabilizing the dispersion of the organic pigment particularly in the dispersion medium is increased. Therefore, as the surfactant, R ² And R ³ Are all methyl groups, and R ¹ Is preferably an N-alkyl betaine type amphoteric surfactant having an alkyl group having 12 to 24 carbon atoms.
[0028]
As the surfactant, for example, Amphitol (registered trademark) 86B manufactured by Kao Corporation, which is commercially available as an aqueous solution or a water-containing slurry [in the general formula (1), R ¹ Is a stearyl group having 18 carbon atoms), Amphitol (registered trademark) 20BS [In the above general formula (1), R ¹ Is a lauryl group having 12 carbon atoms).
[0029]
R in the general formula (1) of the surfactant ¹ The relationship between the chain length and the evaluation items for which the improvement effect is recognized is as follows. For example, in the field of lithographic printing inks in which improvement in transparency as well as coloring power is also an issue, the surfactant in the general formula (1) can be compared with the same amount of the surfactant. R ¹ Is in the range of an alkyl group having 12 to 24 carbon atoms, and a shorter chain length of the alkyl group gives more preferable results. On the other hand, in the field of gravure printing inks in which improvement in viscosity in addition to coloring power is also an issue, the surfactant in the general formula (1) is compared with the same amount of the surfactant. R ¹ Is in the range of an alkyl group having 12 to 24 carbon atoms, and the longer the alkyl group has a longer chain length, the better the result.
[0030]
The ratio of the organic pigment composition obtained by the production method of the present invention is not particularly limited as long as the organic pigment composition contains the organic pigment and the surfactant. The content of the surfactant is preferably 0.5 to 12 parts.
[0031]
The production method of the present invention comprises a first step of producing a crude pigment, and a second step of converting the crude pigment obtained in the first step into a pigment to produce an organic pigment, wherein (1) the first step Is performed in the presence of the surfactant to obtain an organic pigment composition containing the surfactant and the organic pigment, and (2) the second step is performed in the presence of the surfactant. And a method for producing an organic pigment composition containing the surfactant and the organic pigment. Of course, both the first step and the second step can be performed in the presence of the surfactant.
[0032]
However, at least in the first step, the method for producing the organic pigment composition using the surfactant is preferable since a suitable organic pigment composition excellent in all of sharpness, coloring power, and transparency is obtained.
[0033]
The above-mentioned relationship between the chain length of the surfactant and the evaluation item for which the improvement effect is recognized is based on the production method (1) in which the first step is performed in the presence of the surfactant (production method (1)). ], And also in the case of the production method (referred to as production method (2)) of (2) in which the second step is performed in the presence of the surfactant.
[0034]
However, in the case of the production method (1), an optimal organic pigment composition in the present invention can be prepared.
[0035]
Specifically, the method for producing the organic pigment composition of the present invention is based on the theoretical yield of the crude pigment in the case of the production method (1), and in the case of the production method (2), The amount of the surfactant is preferably 0.5 to 12 parts per 100 parts by weight of the surfactant, preferably the crude pigment, based on the actual amount of the surfactant used. This makes it possible to obtain a suitable organic pigment composition in which the surfactant is 0.5 to 12 parts per 100 parts of the organic pigment in terms of mass.
[0036]
According to the production method of the present invention, unlike the case where the surfactant is added to the organic pigment obtained in advance, the surfactant molecules are always interposed between the particles of the crude pigment during the transition from the crude pigment to the pigment. Is disposed, or as a result of the surfactant molecules being adsorbed on the surface of the crude pigment, etc., the aggregation caused by intermolecular hydrogen bonding also occurs in the particle surface state that changes momentarily with pigmentation. It is preferable because it can be effectively inhibited. Hereinafter, this method will be described in detail.
[0037]
In the production method of the present invention, the first step of producing a crude pigment is performed in the presence or absence of the surfactant.
[0038]
Producing a crude pigment in the first step of the present invention means that one or more raw materials are chemically reacted to form a chemical structure of the crude pigment. Since there are many types of crude pigments and the raw materials thereof are also diverse, it is not possible to exemplify a method for producing each of the crude pigments, but this is the common knowledge of those skilled in the art. Regarding the kind of the crude pigment, any of the crude pigments corresponding to the above-mentioned organic pigments can be used. Above all, when an organic pigment composition is produced using a crude benzimidazolone-based azo pigment according to the production method of the present invention, a significant improvement in all of the sharpness, coloring power, and transparency can be obtained as compared with the conventional art.
[0039]
In the production method (1) of the present invention, a crude pigment is produced in the first step in the presence of the surfactant. When the crude pigment is produced in the first step in the presence of the surfactant according to a known and commonly used production method, the product is a crude pigment composition containing the surfactant and the crude pigment. On the other hand, in the production method (2) of the present invention, a crude pigment corresponding to the first step is produced in the absence of the surfactant. Therefore, the product here is a crude pigment not containing the surfactant, and a known and commonly used crude pigment can be used as it is.
[0040]
If it is desired to produce the crude pigment in the first step according to the production method (1) of the present invention, the crude pigment may be produced in the presence of the surfactant according to a known and commonly used production method. Hereinafter, a method for producing a crude quinacridone pigment and a crude benzimidazolone-based azo pigment will be described in detail, taking as an example a case where the reaction is performed in the absence of the surfactant.
[0041]
Crude quinacridone pigment is 2,5-dianilinoterephthalic acid, 2,5-dianilinoterephthalic acid having a halogen atom or a methyl group, or polyphosphoric acid that is 3 to 6 times the mass of the raw material using the above mixture as a raw material. A cyclized compound is synthesized by charging into a reaction vessel and stirring at a temperature of 110 to 140 ° C. for 1 to 5 hours, and then a large excess of the obtained cyclized compound in an amount equivalent to 3 to 15 times the cyclized compound in terms of mass. And a liquid medium such as water or an inorganic acid to obtain a hydrolyzate. Next, the obtained hydrolyzate is filtered and washed to obtain a desired crude quinacridone pigment. This crude quinacridone pigment can be used in a water-containing state or a dried state.
[0042]
The polyphosphoric acid for obtaining the cyclized compound may be adjusted by a known and commonly used method. For example, polyphosphoric acid can be adjusted by adding phosphoric anhydride to 85% phosphoric acid and stirring. For example, phosphoric acid or sulfuric acid can be used as the inorganic acid. As a method for hydrolyzing the cyclized compound, it is preferable to add the cyclized compound while stirring the liquid medium, and after the addition, the hydrolyzate is stirred at a temperature of 10 to 180 ° C. for 0.25 to 3 hours. Obtainable. At this time, as the temperature difference between the cyclized compound to be added and the liquid medium is larger, finer particles are preferably obtained. Filtration, washing and drying of the obtained hydrolyzate can be performed according to a conventional method.
[0043]
In the case of a crude benzimidazolone-based azo pigment, a diazonium salt obtained by reacting a base component with sodium nitrite in a cold mineral acid aqueous solution and a coupler component dissolved in an alkaline aqueous solution according to a conventional method, It is obtained by a diazo coupling reaction. This reaction is usually carried out at a pH of 4 to 13 and a temperature of -5 to 60 ° C. The base component is added to the coupler component, the coupler component is added to the base component, or the base component and the coupler are simultaneously added. The components may be reacted at a constant rate.
[0044]
At this time, if necessary, a buffer or a surface treating agent for controlling the reaction pH to be constant can be present. The type and amount of the buffer are not particularly limited, but sodium acetate or the like can be used. As the surface treatment agent, known additives such as rosins and surfactants can be used. In order to facilitate filtration of the crude pigment, the reaction solution after the coupling reaction can be maintained at a temperature of 60 to 95 ° C. and maintained for 1 to 5 hours. The thus obtained crude benzimidazolone azo pigment can be used in a water-containing state or a dried state.
[0045]
In addition, as a crude pigment other than the crude quinacridone pigment and the crude benzimidazolone-based azo pigment, a crude pigment produced according to a conventionally known production method can be used.
[0046]
In the method for producing an organic pigment composition of the present invention, subsequent to the first step, the crude pigment obtained in the first step is converted into a pigment to obtain an organic pigment.
[0047]
In the second step of the method for producing an organic pigment composition of the present invention, a crude pigment composition or a crude pigment is converted into a pigment to obtain an organic pigment composition. In the production method (1) of the present invention, a crude pigment corresponding to the first step is produced in the presence of the surfactant, and therefore, in the second step, pigmentation is performed in the absence of the surfactant. be able to. On the other hand, in the production method (2) of the present invention, since the crude pigment corresponding to the first step is produced in the absence of the surfactant, the second step is carried out in the presence of the surfactant. Is performed.
[0048]
Incidentally, the method of Patent Document 7 described in the prior art corresponds to the production method (2) in light of the production method of the organic pigment composition of the present invention, and the first step is performed in the absence of the surfactant. An organic pigment composition is obtained by subjecting the produced crude pigment to a pigmentation treatment corresponding to a second step described below in the presence of the surfactant.
[0049]
As the pigmentation method, a conventionally known solvent salt milling method (referred to as the former method) and a solvent method (referred to as the latter method) can be employed. Hereinafter, a case where the reaction is performed in the absence of the surfactant will be described as an example. If it is desired to carry out the pigmentation of the crude pigment in the second step according to the production method (2) of the present invention, the following pigmentation may be carried out in the presence of the surfactant.
[0050]
In the former method, a certain amount of the crude pigment is prepared in the presence of a water-soluble inorganic salt in an amount equivalent to 3 to 20 times the crude pigment in terms of mass and a water-soluble organic solvent in an amount equivalent to 0.5 to 10 times the crude pigment. It is a method of kneading at 60 to 120 ° C. Examples of the water-soluble inorganic salt include sodium chloride and sodium sulfate, and examples of the water-soluble organic solvent include diethylene glycol and triethylene glycol. The kneading time at this time is not particularly limited, but is preferably 0.5 to 8 hours. The product obtained by the solvent salt milling method in this manner can be converted into an organic pigment composition through, for example, washing with water or hot water and, if necessary, drying and the like.
[0051]
The latter method is to mix and heat the crude pigment and a large excess of water and / or organic solvent over the crude pigment. More specifically, a method in which a fixed amount of the crude pigment is stirred at 80 to 150 ° C. in a large excess of water, an organic solvent or a mixture thereof in an amount equivalent to 3 to 15 times in terms of mass of the crude pigment. Examples of the organic solvent include xylene, 2-butanol, dimethylformamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, dimethylimidazolidinone, and the like. The stirring time at this time is not particularly limited, but usually 0.5 to 15 hours is desirable. The organic solvent may contain an acid, a base, a surface treating agent, and the like in accordance with the suitability of the organic pigment composition to be used. The product obtained by the solvent method in this manner can be obtained as an organic pigment composition by, for example, filtering, washing with water or hot water, and drying if necessary.
[0052]
As a method of forming a pigment in the present invention in comparison with the conventional conditions, it is preferable to employ the above-mentioned solvent method capable of obtaining an organic pigment composition with lower energy than the solvent milling method.
[0053]
Thus, the production method (1) in which the first step is performed in the presence of the surfactant, the production method (2) in which the second step is performed in the presence of the surfactant, or the production method in the presence of the surfactant An organic pigment composition containing the surfactant and the organic pigment is obtained by a production method in which both the first step and the second step are performed.
[0054]
The organic pigment composition obtained from the production method of the present invention in which each of the above preferable methods is combined is an aggregate having a small particle size and a weak bonding force between particles, as compared with the organic pigment composition obtained from the conventional production method. Is preferable because the BET specific surface area by the nitrogen adsorption method can be increased.
[0055]
The BET specific surface area of the organic pigment composition obtained by the production method of the present invention by a nitrogen adsorption method is generally 50 to 90 m. ² / G.
[0056]
In addition, the BET specific surface area in the nitrogen adsorption method in the present invention is based on Appendix 2 of Japanese Industrial Standard (JIS) Z 8830-1990 (Method for measuring specific surface area of powder by gas adsorption; sample pretreatment; temperature). 120 ° C., 20 minutes, sampling amount: 0.25 g, measuring method of adsorption amount; one-point method, nitrogen partial pressure; 0.3). Micro Data 4232II manufactured by Micro Data Co., Ltd. is a specific surface area measuring device based on this.
[0057]
The pigment dispersion of the present invention comprises the organic pigment composition obtained by the production method of the present invention and a dispersion medium, and can be prepared by mixing these as essential components. This dispersion medium may be a liquid or a solid. The organic pigment composition of the present invention can be made into a pigment dispersion by including a resin as an essential component of the dispersion medium. As the resin at this time, a thermoplastic resin is generally used.
[0058]
The pigment dispersion containing the organic pigment composition and the thermoplastic resin obtained by the production method of the present invention includes a solid pigment dispersion and a liquid pigment dispersion depending on the properties thereof. The pigment dispersion of the present invention is supplied, for example, by dispersing an organic pigment composition containing an organic pigment and the surfactant in a thermoplastic resin for pigment dispersion.
[0059]
The pigment dispersion of the present invention is a pigment dispersion composed of only an organic pigment composition and a thermoplastic resin obtained from the production method of the present invention, for example, a masterbatch for plastic coloring and a master for color toner for electrostatic image development. Not only batches, but also pigment dispersions further added with resins such as thermosetting resins, solvents, and other additives, such as lithographic printing inks, gravure printing inks, paints, colored plastic molded products, and electrostatic image development It includes color toners, resist inks for producing color filters, and the like.
[0060]
In the case of producing the pigment dispersion of the present invention, the powder pigment composition and the solid thermoplastic resin may be mixed at a temperature equal to or higher than the melting temperature of the latter resin.
[0061]
In general, a water-containing organic pigment composition can prevent aggregation between pigment particles in a drying step, and therefore has less aggregation than a powder state, and is advantageous for applications in which transparency and coloring power are emphasized. This is to promote the aggregation between the pigment particles during drying due to the surface tension of water existing between the pigment particles, and therefore, the organic pigment composition in a water-containing state, a liquid thermoplastic resin or a thermoplastic resin organic solvent. By mixing the solution with water or a solvent having a boiling point lower than that of water, the water on the surface of the pigment particles is directly replaced by a resin or an organic solvent, and a pigment dispersion having more excellent transparency and coloring power can be obtained. In this case, if necessary, water or an organic solvent may be removed as appropriate.
[0062]
Therefore, in producing the pigment dispersion in the present invention, when the organic pigment composition and the thermoplastic synthetic resin obtained from the production method of the present invention are flushed as essential components, the dispersion is more excellent and the result is more transparent. A pigment dispersion having excellent properties can be obtained.
[0063]
Here, flushing refers to a process of mixing a water-containing organic pigment composition and a thermoplastic resin as essential components, inverting the organic pigment composition from an aqueous phase to an oil phase, and then removing water. . The removal of water can be performed by a combination of decantation and heating / vacuum suction.
[0064]
The organic pigment composition used in the present invention may be dispersed only in a thermoplastic resin, or may be dispersed in a vehicle for a printing ink or a vehicle for a paint containing the thermoplastic resin as an essential component.
[0065]
As the thermoplastic resin, for example, a resin such as a polyester resin, a polyamide resin, a styrene resin, an acrylic resin, a polyolefin, a polyalkylene terephthalate, or a polyvinyl chloride resin can be used as the resin for dispersion.
[0066]
For example, the vehicle of the lithographic printing ink is, for example, a resin such as rosin-modified phenol resin, petroleum resin, or alkyd resin in an amount of 20 to 50 (mass)%, and an animal or vegetable oil such as linseed oil, tung oil, soybean oil in an amount of 0 to 30 (mass) %, Solvents such as n-paraffin, isoparaffin, naphthene, α-olefin, and aromatic are manufactured from 10 to 60 (mass)%, and other additives such as solubilizers and gelling agents are manufactured from several (mass)% raw materials. Is done.
[0067]
In the case of gravure printing inks and vehicles for flexographic printing inks, for example, rosins, maleic acid resins, polyamide resins, vinyl resins, cyclized rubbers, chlorinated rubbers, ethylene-vinyl acetate copolymer resins, urethane resins, polyester resins, 10 to 50 (mass)% of one or more resins selected from alkyd resins, nitrocellulose, cellulose acetate and the like, and solvents 30 to 80 (mass) such as alcohols, toluene, n-hexane, ethyl acetate, cellosolve, and butyl cellosolve. % Of raw materials.
[0068]
Examples of vehicles for coatings include resins such as alkyd resins, epoxy resins, acrylic resins, polyurethane resins, polyester resins, melamine resins, urea resins, and water-soluble resins in the range of 20 to 80 (mass)%, hydrocarbons, alcohols, ketones. It is produced from raw materials of 10 to 60 (mass)% of solvents such as water and water.
[0069]
In the case of obtaining a colored plastic molded product, a thermoplastic resin (plastic) for thermoforming such as injection molding or press molding, for example, a polyolefin such as polyethylene or polypropylene or a polyvinyl chloride resin is used as a resin for dispersion. . Incidentally, the pigment dispersion of the present invention obtained by using these resins can be formed into a colored molded article by molding into a required shape.
[0070]
In order to obtain a toner for developing an electrostatic image, a thermoplastic resin which forms a solid film at room temperature, such as a polyester resin, a polyamide resin, a styrene resin, and an acrylic resin, is used as the dispersing resin. As will be described in detail later, the room temperature solid pigment dispersion of the present invention obtained by using these resins is pulverized and classified into particles having a required particle size, thereby forming a toner for electrostatic image development. You can do it.
[0071]
These pigment dispersions are mixed with other resins, rubbers, additives, pigments, dyes, and the like, if necessary, to form final printing inks, paints, colored plastic molded articles, toners for developing electrostatic images, color filters, etc. Adjusted and used.
[0072]
Examples of a disperser for dispersing an organic pigment composition in a thermoplastic resin when producing a pigment dispersion include dispersers, homomixers, bead mills, two-roll, three-roll, normal pressure and pressure kneaders, ultrasonic A known disperser such as a disperser may be used, but is not limited thereto.
[0073]
The dispersion conditions vary depending on the dispersion medium and the disperser, and the dispersion temperature and dispersion time are not limited. The dispersion temperature is from room temperature to 300 ° C., preferably from room temperature to 240 ° C., and the dispersion time is from 1 minute to 120 hours, preferably from 3 minutes. Minutes to 7 hours.
[0074]
The content of the organic pigment composition in the pigment dispersion is not particularly limited and is about several to 50 (mass)%, but varies depending on the use, and the organic pigment composition of the present invention in the final product The content is, for example, 13 to 20 (mass)% for lithographic printing ink, 3 to 20 (mass)% for gravure printing ink, 0.3 to 15 (mass)% for paint, and 0.01 to 0.01 for plastic coloring applications. １1 (mass)%, about 2 to 10 (mass)% for the electrostatic image developing toner, and about 4 to 7 (mass)% when used as a resist ink for color filter applications.
[0075]
The pigment dispersion of the present invention can be used, for example, as a paste color or a dry color, but is itself a non-colored thermoplastic resin used as a binder resin for the thermoforming or electrostatic image developing toner. If the resin is used as a coloring masterbatch, it is possible to obtain a uniformly colored molded product or a toner for developing an electrostatic image in a shorter time than in the case where the resin is directly and uniformly mixed with the entire amount of the thermoplastic resin. it can.
[0076]
In the pigment dispersion of the present invention containing an organic pigment composition and a thermoplastic resin, in order to maximize the performance of the organic pigment composition, as described above, a method for producing a dispersion by a flushing method is particularly effective. .
[0077]
In particular, in applications where transparency of the pigment is required, the pigment is easily mixed with the organic resin composition in a powder state, which tends to cause strong agglomeration of the pigment particles during drying, and the dispersibility in the thermoplastic resin is easily reduced. By flushing the water-containing organic pigment composition with a thermoplastic resin, a pigment dispersion having higher quality can be obtained.
[0078]
The feature of the organic pigment composition obtained from the production method of the present invention, which provides a coloring medium having excellent transparency as well as coloring power, is exhibited when a pigment dispersion is prepared therefrom. In the field of a full-color toner in which a color image is formed by superimposing a developing toner, an effect of obtaining a clear image with good color development can be obtained.
[0079]
The toner for developing an electrostatic charge image produced using the organic pigment composition and the pigment dispersion obtained by the production method of the present invention as a component is a one-component color toner containing a magnetic material in the toner (magnetic one-component development). Color toner), non-magnetic one-component color toner containing no magnetic material (non-magnetic one-component development color toner), or two-component color developer color toner mixed with a carrier (two-component development color toner) Can be used as
[0080]
The one-component color magnetic toner can be composed of, for example, a colorant, a binder resin, a magnetic powder, and other additives typified by a charge control agent (CCA) and a release agent, similarly to those usually used.
[0081]
The amount of the organic pigment composition in the toner for developing an electrostatic image is not particularly limited, but is preferably used in a ratio of 0.5 to 25 parts by mass with respect to 100 parts by mass of the binder resin. The amount is more preferably 4 to 10 parts by mass with respect to 100 parts by mass of the binder resin in order to make the charging performance more remarkable.
[0082]
As the binder resin used in the electrostatic image developing toner, any of the known and common resins exemplified as the thermoplastic resin can be used, but a synthetic resin showing adhesiveness under application of heat or pressure, a natural resin, Any of natural rubber, synthetic rubber, and synthetic wax can be used.
[0083]
Examples of the synthetic wax used in the electrostatic image developing toner include chlorinated paraffin wax, paraffin wax, polypropylene wax, PVC, and the like.
[0084]
Examples of the natural resin include balsam resin, rosin, shellac, and koval, and these resins are one or more resins selected from vinyl resins, acrylic resins, alkyd resins, and phenol resins described below. May be denatured.
[0085]
Examples of natural or synthetic rubber substances include natural rubber, chlorinated rubber, cyclized rubber, polyisobutylene rubber, ethylene-propylene rubber, polybutadiene rubber, butyl rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, and silicone. Rubber, fluororubber and the like.
[0086]
The binder resin used when preparing the toner for developing an electrostatic image is not limited to these, and two or more binder resin components may be appropriately mixed and used.
[0087]
As the binder resin, a glass transition temperature of 45 to 85 ° C. by a differential scanning calorimeter (DSC), a constant load extrusion type capillary rheometer (elevated flow tester; Shimadzu flow tester CFT-C, manufactured by Shimadzu Corporation) Shape, piston cross section 1cm ² , Cylinder pressure 0.98 MPa, die length 1 mm, die hole diameter 1 mm, measurement start temperature 50 ° C., temperature rising rate 6 ° C./min, sample viscosity 1.5 g) ⁵ It is preferable that the temperature at which poise is formed is 95 to 170 ° C.
[0088]
Of these binder resins, styrene resin, acrylic resin, polyester resin and epoxy resin can be advantageously used from the viewpoint of their transparency and the hue of the toner for developing electrostatic images, and polyester resins are particularly preferable.
[0089]
The magnetic powder used when preparing the toner for developing an electrostatic image is not particularly limited, but those that hardly affect the color in which the color of itself is reproduced can be preferably used. Iron oxide such as iron oxide, yellow γ-iron oxide and ferrite; metals such as iron, cobalt and nickel, or alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin and zinc And organic magnetic substances such as poly-1,4-bis (2,2,6,6-tetramethyl-4-oxyl-4-piperidyl-1-oxyl) butadiemporphyrin metal complex, and mixtures thereof. Can be Of these, yellow γ-iron oxide is particularly preferred in view of hue.
[0090]
As these magnetic powders, those having an average particle diameter of 0.1 to 1 [mu] m can be used, and those having a mean particle diameter of 0.1 to 0.5 [mu] m are preferably used in view of charging stability and hue. The amount of these components to be contained in the toner for developing an electrostatic image can be used in an amount of 30 to 150 parts with respect to 100 parts of the binder resin in terms of mass, and the binder resin can be used in terms of mass in terms of charge stability and hue. 40 to 120 parts per 100 parts is preferred.
[0091]
In preparing the toner for developing an electrostatic image, various plasticizers and resistors for adjusting the thermal characteristics, electrical characteristics, physical characteristics, etc. of the toner for developing an electrostatic image as needed, in addition to the above-mentioned components. Adjusters and charge control agents may be further added.
[0092]
Examples of the plasticizer include dibutyl phthalate and dioctyl phthalate. Examples of the resistance modifier include tin oxide, lead oxide, and antimony oxide. Examples of the charge control agent include quaternary ammonium salts, pyridinium salts, and metal-containing dyes. Respectively.
[0093]
Further, in the present invention, after the toner particles for electrostatic image development are produced, ₂ , Al ₂ O ₃ , SiO ₂ The powder may be added to improve the fluidity of the toner, or zinc stearate, phthalic acid or the like may be added to prevent deterioration of the photoconductor.
[0094]
In preparing the toner for developing an electrostatic image from the organic pigment composition and the pigment dispersion according to the present invention, an extremely general production method can be employed regardless of a specific production method. For example, the above-mentioned components are mixed by a kneading means such as an extruder, a two-roller, a three-roller or a heating kneader to obtain a kneaded product containing the organic pigment composition and the pigment dispersion of the present invention, and the resultant is cooled. Thereafter, the mixture is agitated by a pulverizer such as a jet mill, classified by an air classifier, and formed into particles, thereby developing an electrostatic image of a target powder from the organic pigment composition and the pigment dispersion of the present invention. A toner for use is obtained.
[0095]
By utilizing the feature that the organic pigment composition obtained by the production method of the present invention can be easily dispersed in a dispersion medium than before, an electrostatic charge image is formed by a wet method such as a phase inversion emulsification method or an acid precipitation method. It can also be applied to a developing toner. Since the toner for developing an electrostatic image obtained by these methods is in the form of spherical composite particles in which an organic pigment is coated on a binder resin, it has better characteristics than the above-mentioned dry method.
[0096]
Further, using a binder resin suitable for the preparation of the toner for developing an electrostatic image as described above as a thermoplastic resin, a master batch of the pigment dispersion of the present invention containing an organic pigment composition at a high concentration is prepared in advance. When kneading by diluting with a binder resin for toner which is the same as or different from that described above to obtain a predetermined organic pigment composition concentration, when manufacturing without a master batch, Rather, it is possible to produce a toner for developing an electrostatic image capable of obtaining an image having more excellent transparency.
[0097]
Furthermore, by combining the above-mentioned flushing and masterbatch techniques, in comparison with the case of using the same resin, it is possible to produce a toner for developing an electrostatic charge image which is most excellent in transparency, good in color development and a clear image can be obtained. I can do it.
[0098]
The color toner for developing an electrostatic image according to the present invention is a particulate dispersion in which an organic pigment composition is dispersed in the binder resin, and the average particle diameter of the toner particles for developing an electrostatic image is 3. It is preferably from 15 to 15 μm.
[0099]
When used as a two-component color developer color toner, the same colorants, binder resins, and other additives as described above for the one-component color magnetic toner can be used.
[0100]
Further, as a carrier used in the toner for developing an electrostatic image, for example, iron powder, nickel powder, ferrite powder, glass beads, or a styrene-acrylic ester copolymer, styrene-methacrylic acid having these as a core material Ester copolymers, acrylic acid ester polymers, methacrylic acid ester polymers, silicone resins, polyamide resins and the like or a mixture of these resins can be used, and those having a particle diameter in the range of 50 to 300 μm can be used. preferable.
[0101]
A color toner for a two-component color developer can be obtained by friction-mixing these carrier particles and the color toner of the present invention with a horizontal cylindrical or V-shaped container rotating mixer.
[0102]
In order to obtain an appropriate image density, the mixing ratio of the carrier and the electrostatic image developing toner is usually 2 to 10 parts, preferably 4 to 6 parts, per 100 parts of the carrier in terms of mass. Can be used in a range of parts.
[0103]
【Example】
Hereinafter, the present invention will be described in detail with reference to Production Examples, Examples, and Comparative Examples. In the examples, parts and% are based on mass.
[0104]
Example 1 (Experimental example of including the surfactant only during pigmentation)
<First step>
While stirring and dispersing 271.9 parts of 1,2-bis (2-aminophenoxy) -ethane in 2700 parts of water, 645.9 parts of 35% hydrochloric acid was added. After stirring for 1 hour, ice was added to adjust the temperature to 0 to 5 ° C., and 404.2 g of a 40% aqueous sodium nitrite solution was added to carry out a diazotization reaction. After stirring for 1 hour or more, in order to remove excess nitrite, 118.1 parts of a 10% aqueous solution of sulfamic acid was added and stirred for 30 minutes or more. Further, 27 parts of activated carbon was added and stirred for 30 minutes or more, and a bisdiazonium salt solution was added. Was prepared.
[0105]
On the other hand, 539.2 parts of 5-acetoacetylamino-benzimidazolone was dispersed in 4000 parts of water, and then 712.9 parts of a 25% aqueous sodium hydroxide solution was added to dissolve the same to obtain a coupler component. The diazo component and the coupler component were adjusted to 8100 parts and 5400 parts by adding water and ice, respectively.
[0106]
After adding 35.8 parts of 90% acetic acid to 8100 parts of water, the temperature of this solution was adjusted to 40 ° C., and the pH was adjusted to 5.0. For coupling, the diazo component was added at a constant rate while adjusting the pH to 8.0 by adding and adjusting the coupler component. The coupling was completed in about 3 hours while adding ice or a 5% aqueous sodium hydroxide solution as needed to maintain the temperature at 40 ° C. and pH 8.0 during the coupling. After confirming that the unreacted diazo component was not contained in the reaction solution, the mixture was heated to 90 ° C. and maintained for 1 hour. Next, filtration and washing with water were performed to obtain a crude benzimidazolone-based azo pigment in a water-containing state.
[0107]
<Second step>
In a pressurizable reaction vessel equipped with a stirrer, 131.1 parts (20 parts in terms of solid content) of the above-mentioned hydrous crude benzimidazolone-based azo pigment, Amphitol (registered trademark) 86B [stearyl betaine manufactured by Kao Corporation] Water-containing paste. In the general formula (1), R ² And R ³ Are all methyl groups, and R ¹ Mainly contains a surfactant having a stearyl group. 26% solids. 1.58 parts). After adjusting the mass in the container to 600 parts by adding water, the temperature was raised from room temperature to 140 ° C. over about 2 hours with stirring, kept for 5 hours, cooled to room temperature, and the contents were taken out. After the contents were filtered and washed, they were dried at 90 ° C. for 12 hours or more. The dried solid was pulverized with a juicer mixer to obtain an organic pigment composition containing Amphitol (registered trademark) 86B and a benzimidazolone-based azo pigment.
[0108]
Example 2 (Experimental example in which the surfactant is included only during crude pigment production)
<First step>
While stirring and dispersing 271.9 parts of 1,2-bis (2-aminophenoxy) -ethane in 2700 parts of water, 645.9 parts of 35% hydrochloric acid was added. After stirring for 1 hour, ice was added to adjust the temperature to 0 to 5 ° C., and 404.2 g of a 40% aqueous sodium nitrite solution was added to carry out a diazotization reaction. After stirring for 1 hour or more, in order to remove excess nitrite, 118.1 parts of a 10% aqueous solution of sulfamic acid was added and stirred for 30 minutes or more. Further, 27 parts of activated carbon was added and stirred for 30 minutes or more, and a bisdiazonium salt solution was added. Was prepared.
[0109]
On the other hand, 557.4 parts of 5-acetoacetylamino-benzimidazolone was dispersed in 4000 parts of water, and then 712.9 parts of a 25% aqueous sodium hydroxide solution was added to dissolve it to obtain a coupler component. The diazo component and the coupler component were adjusted to 8100 parts and 5400 parts by adding water and ice, respectively.
[0110]
After adding 35.8 parts of 90% acetic acid to 8100 parts of water, the temperature of the solution is adjusted to 40 ° C. and the pH to 5.0. For coupling, the pH was adjusted to 8.0 by adding and adjusting the coupler component, and then 157.4 parts of Amphitol (registered trademark) 86B was added, and the diazo component was added at a constant rate simultaneously with the coupler component. The coupling was completed in about 3 hours while adding ice or a 5% aqueous sodium hydroxide solution as needed to maintain the temperature at 40 ° C. and pH 8.0 during the coupling.
[0111]
After confirming that the unreacted diazo component was not contained in the reaction solution, the mixture was heated to 90 ° C. and maintained for 1 hour. Next, the mixture was filtered and washed with water to obtain a crude pigment composition containing Amphitol (registered trademark) 86B in a water-containing state and a crude benzimidazolone-based azo pigment.
[0112]
<Second step>
In a pressurizable reaction vessel equipped with a stirrer, 133.7 parts (20 parts in terms of solid content) of the above water-containing crude pigment composition were charged. After adjusting the mass in the container to 600 parts by adding water, the temperature was raised from room temperature to 140 ° C. over about 2 hours with stirring, kept for 5 hours, cooled to room temperature, and the contents were taken out. After the contents were filtered and washed, they were dried at 90 ° C. for 12 hours or more. The dried solid was pulverized with a juicer mixer to obtain an organic pigment composition containing Amphitol (registered trademark) 86B and a benzimidazolone-based azo pigment.
[0113]
Comparative Example 1 (Experimental example without betaine-type amphoteric surfactant)
The same operation as in Example 1 was carried out except that 131.1 parts (20 parts in terms of solid content) of a crude benzimidazolone pigment containing water was used without using Amphitol (registered trademark) 86B, and no surfactant was used. A benzimidazolone azo pigment was obtained.
[0114]
Comparative Example 2
136.4 parts of Amphitol (registered trademark) 55AB instead of 157.4 parts of Amphitol (registered trademark) 86B [a water-containing paste of cocamidopropyl betaine manufactured by Kao Corporation. A betaine-type amphoteric surfactant having a structure not included in the general formula (1). 30% solids. ] Was added in the same manner as in the first step of Example 2 to obtain a water-containing crude pigment composition containing Amphitol (registered trademark) 55AB and a crude benzimidazolone-based azo pigment.
Next, the Amphitol (registered trademark) 55AB and the benzimidazo were prepared in the same manner as in the second step of Example 2 except that 66.3 parts (20 parts in terms of solid content) of the crude pigment composition was charged and heated and stirred. An organic pigment composition containing a lon-based azo pigment was obtained.
[0115]
Comparative Example 3
Instead of 157.4 parts of Amphitol (registered trademark) 86B, 116.9 parts of Amphitol (registered trademark) 20N [lauryl dimethylamine oxide type surfactant manufactured by Kao Corporation. A surfactant having a structure not included in the general formula (1). 35% solids. ] Was added in the same manner as in the first step of Example 2 to obtain a water-containing crude pigment composition containing Amphitol (registered trademark) 20N and a crude benzimidazolone-based azo pigment.
Next, the Amphitol (registered trademark) 20N and the benzimidazo were treated in the same manner as in the second step of Example 2 except that 82.3 parts of the crude pigment composition (20 parts in terms of solid content) was charged and heated and stirred. An organic pigment composition containing a lon-based azo pigment was obtained.
[0116]
Comparative Example 4
136.4 parts of Amphitol (registered trademark) 20HD [lauryl hydroxysulfobetaine manufactured by Kao Corporation instead of 157.4 parts of Amphitol (registered trademark) 86B]. A betaine-type surfactant having a structure not included in the general formula (1). 30% solids. ] Was added in the same manner as in the first step of Example 2 to obtain a water-containing crude pigment composition containing Amphitol (registered trademark) 20HD and a crude benzimidazolone-based azo pigment.
Next, the above-mentioned Amphitol (registered trademark) 20HD and benzimidazo were prepared in the same manner as in the second step of Example 2 except that 77.3 parts of the crude pigment composition (20 parts in terms of solid content) were charged and heated and stirred. An organic pigment composition containing a lon-based azo pigment was obtained.
[0117]
Comparative Example 5
102.3 parts of Amphitol (registered trademark) 20YB [2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine manufactured by Kao Corporation instead of 157.4 parts of Amphitol (registered trademark) 86B. A surfactant having a structure not included in the general formula (1). 40% solids. ] Was added in the same manner as in the first step of Example 2 to obtain a water-containing crude pigment composition containing Amphitol (registered trademark) 20YB and a crude benzimidazolone-based azo pigment.
Subsequently, the Amphitol (registered trademark) 20YB and the benzimidazo were treated in the same manner as in the second step of Example 2 except that 75.8 parts (20 parts in terms of solid content) of the crude pigment composition were charged and heated and stirred. An organic pigment composition containing a lon-based azo pigment was obtained.
[0118]
Comparative Example 6
136.4 parts of Amphitol (registered trademark) 20AB instead of 157.4 parts of Amphitol (registered trademark) 86B [lauric amide propyl betaine manufactured by Kao Corporation. A betaine-type surfactant having a structure not included in the general formula (1). 30% solids. ] Was added in the same manner as in the first step of Example 2 to obtain a water-containing crude pigment composition containing Amphitol (registered trademark) 20AB and a crude benzimidazolone-based azo pigment.
Next, the above-mentioned Amphitol (registered trademark) 20AB and benzimidazo were carried out in the same manner as in the second step of Example 2 except that 78.1 parts of this crude pigment composition (in terms of solid content: 20 parts) were charged and heated and stirred. An organic pigment composition containing a lon-based azo pigment was obtained.
[0119]
Comparative Example 7 (Experimental example corresponding to Patent Document 7)
In the same manner as in Example 1 except that 1.37 parts of Amphitol (registered trademark) 55AB was used instead of 1.58 parts of Amphitol (registered trademark) 86B, the above-mentioned Amphitol (registered trademark) 55AB and benzimidazolone were used. An organic pigment composition containing a azo pigment was obtained.
[0120]
Comparative Example 8
In the same manner as in Example 1 except that 1.17 parts of Amphitol (registered trademark) 20N was used instead of 1.58 parts of Amphitol (registered trademark) 86B, the above-mentioned Amphitol (registered trademark) 20N and benzimidazolone were used. An organic pigment composition containing a azo pigment was obtained.
[0121]
Comparative Example 9 (Experimental example corresponding to Patent Document 7)
In the same manner as in Example 1 except that 1.37 parts of Amphitol (registered trademark) 20HD was used instead of 1.58 parts of Amphitol (registered trademark) 86B, the above-mentioned Amphitol (registered trademark) 20HD and benzimidazolone were used. An organic pigment composition containing a azo pigment was obtained.
[0122]
Comparative Example 10 (Experimental example corresponding to Patent Document 7)
In the same manner as in Example 1 except that 1.03 part of Amphitol (registered trademark) 20YB was used instead of 1.58 part of Amphitol (registered trademark) 86B, the above-mentioned Amphitol (registered trademark) 20YB and benzimidazolone were used. An organic pigment composition containing a azo pigment was obtained.
Comparative Example 11 (Experimental example corresponding to Patent Document 7)
In the same manner as in Example 1 except that 1.37 parts of Amphitol (registered trademark) 20AB was used instead of 1.58 parts of Amphitol (registered trademark) 86B, the above-mentioned Amphitol (registered trademark) 20AB and benzimidazolone were used. An organic pigment composition containing a azo pigment was obtained.
[0123]
The various surfactants used in the comparative examples are as follows.
[0124]
Amphitol (registered trademark) 55AB (mainly a compound in which R is an alkyl group having 11 and 13 carbon atoms in the following general formula) and 20AB (R is an alkyl group having 11 carbon atoms in the following general formula) Compound-based)
[0125]
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[0126]
Amphitol (registered trademark) 20N (main component is a compound represented by the following general formula, wherein R is an alkyl group having 12 carbon atoms)
[0127]
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[0128]
Amphitol (registered trademark) 20HD (mainly a compound represented by the following general formula, wherein R is an alkyl group having 12 carbon atoms)
[0129]
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[0130]
Amphitol (registered trademark) 20YB (mainly a compound represented by the following general formula wherein R is an alkyl group having 11 or 13 carbon atoms)
[0131]
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[0132]
Evaluation method
Lithographic printing ink test
Each organic pigment composition obtained in Examples 1 and 2 and Comparative Examples 2 to 11, the organic pigment obtained in Comparative Example 1, and MG-63 (for lithographic printing ink manufactured by Dainippon Ink and Chemicals, Inc.) After the varnish was mixed with the following composition, dispersion of 100 rotations was repeated three times under a load of 150 lbs by using a Hoover muller to prepare an offset ink for evaluation.
0.4 parts of each organic pigment composition or organic pigment
1.6 parts of MG-63
[0133]
The tinting strength was determined by kneading 1 part of the offset ink adjusted as described above, and 5 parts of a blue reference ink composed of copper phthalocyanine blue pigment, titanium white pigment and varnish with a Hoover Mahler under 100 lbs. The adjusted green ink is spread on art paper, and the developed plate obtained from Example 1 is used as a standard, and is determined by 7 levels of visual judgment [1 (small coloring power) >> 7 (large coloring power)]. did.
[0134]
The transparency was evaluated by spreading (drawing down) the offset ink on art paper. By a relative evaluation using a developed plate using the organic pigment composition obtained in Example 1 as a standard, the transparency was visually judged in 7 steps [1 (small transparency) >> 7 (large transparency)]. did.
[0135]
As a method for quantifying the sharpness, a developed plate obtained by spreading ink was measured with a spectrophotometer to determine the magnitude of chroma (C * value). The measurement was performed using a spectrophotometer CM-2600d manufactured by Minolta Co., Ltd.
[0136]
The evaluation results obtained for Examples 1 and 2 and Comparative Examples 1 to 11 are summarized in Table 1.
[0137]
[Table 1]
Table 1

[0138]
Regarding the organic pigment composition produced using the betaine-type amphoteric surfactant in the second step, as can be seen from the comparison between Example 1 and Comparative Example 2, even the betaine-type amphoteric surfactant is used in the present invention. Those using the surfactant represented by the general formula (1) have excellent coloring power, transparency and saturation, but are not included in the general formula (1) It is apparent that those using the betaine type surfactant (which is described as the best in Reference 7) are inferior in tinting strength and chroma. In addition, the organic pigment composition of Example 1 has improved tinting strength as compared with Comparative Example 1 which is an organic pigment not treated with a surfactant, whereas the organic pigment composition of Comparative Example 2 has Contrary to the tendency in Example 1, the coloring power decreases.
[0139]
Further, Example 1 relating to an organic pigment composition produced using a betaine-type amphoteric surfactant in the second step, and Example 2 relating to an organic pigment composition produced using a betaine-type amphoteric surfactant in the first step As can be seen from the comparison with the above, when the same betaine-type surfactant is used, the organic pigment composition produced using the betaine-type amphoteric surfactant in the first step has better coloring power and transparency. The improvement is remarkable, and it is clear that the coloring power, transparency, and saturation are all excellent.
[0140]
Further, as can be seen from a comparison between Comparative Example 7 and Comparative Example 2, the organic pigment composition produced using a betaine surfactant not included in the general formula (1) is represented by the general formula (1). Since no improvement effect of the coloring power between Examples 1 and 2 was observed for the organic pigment composition produced using the betaine-type surfactant, the formula (1) was used in the present invention. It is clear that the betaine-type surfactant produced exhibits a specific effect that cannot be expected from other surfactants in the method for producing an organic pigment.
[0141]
Gravure printing ink test
The organic pigment compositions obtained in Examples 1 and 2 and Comparative Examples 2 to 4 and the organic pigment obtained in Comparative Example 1 were weighed in a 250 ml container with the following composition, and were ground for 120 minutes with a paint conditioner. A yellow urethane gravure ink was prepared.
18.3 parts of toluene
Methyl ethyl ketone 10.1 parts
Urethane resin varnish 19.8 parts
11.8 parts of each organic pigment composition or organic pigment
180 parts of steel beads
[0142]
Immediately after the production of the produced urethane gravure-based ink, the ink viscosity was measured using a B-type viscometer at 20 ° C. and a rotation speed of 12 rpm. p. m. , 60r. p. m. Was measured. The produced urethane gravure ink was spread on a polyester film with a bar coater (Webstar No. 6), and the coating film was measured using a colorimeter D186 (manufactured by Gretag). The density value was measured with a Y filter to determine coloring power, and the density value was measured with a B filter to determine transparency. Similarly, 60 ° gloss was measured with a haze-gloss reflectometer (manufactured by Big-Gardner). The results are shown in Table 2 as relative values when Comparative Example 1 was used as a standard. At this time, the viscosity is desirably as small as the relative value, and the tinctorial strength, transparency and gloss are desirably as large as possible. The chroma in Examples 1 and 2 was superior to that of Comparative Examples 1 to 4.
[0143]
[Table 2]
Table 2

[0144]
【The invention's effect】
The method for producing an organic pigment composition according to the present invention comprises a first step of producing a crude pigment, and a second step of pigmentating the crude pigment obtained in the first step to obtain an organic pigment. Performing the step and / or the second step in the presence of a betaine-type amphoteric surfactant, the method for producing an organic pigment composition containing a betaine-type amphoteric surfactant and an organic pigment, wherein the betaine-type amphoteric surfactant is Since the compound represented by the specific general formula (1) is used, it is finer than that of a conventional betaine-type amphoteric surfactant when it is used in either the first step or the second step. Less aggregation.
Therefore, the dispersibility of the organic pigment composition in the dispersion medium that is the coloring medium is excellent, and the coloring power, transparency, and clarity of the pigment dispersion that is the coloring medium can all be more excellent. It has a particularly remarkable effect.
[0145]
In particular, when the pigment dispersion of the present invention is used in printing inks, paints, colored plastic molded articles, toners for developing electrostatic images, resist inks for color filters, and the like, more excellent coloring power can be imparted.

Claims (7)

A first step of producing a crude pigment; and a second step of converting the crude pigment obtained in the first step into a pigment to obtain an organic pigment, wherein the first step and / or the second step is a betaine-type amphoteric interface. In the method for producing an organic pigment composition containing a betaine-type amphoteric surfactant and an organic pigment in the presence of a surfactant, betaine represented by the following general formula (1) is used as the betaine-type amphoteric surfactant. A method for producing an organic pigment composition comprising a betaine-type amphoteric surfactant and an organic pigment, comprising using a type-amphoteric surfactant.
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General formula (1)

[In the general formula (1), R ¹ is an aliphatic hydrocarbon group having 8 to 24 carbon atoms,
R ² and R ³ are the same or different and are a hydrogen atom or a methyl group. ] The method for producing an organic pigment composition according to claim 1, wherein at least in the first step, a betaine-type amphoteric surfactant represented by the general formula (1) is used. The betaine-type amphoteric surfactant represented by the general formula (1) is used in an amount of 0.5 to 12 parts per 100 parts by mass of the theoretical yield or the actual use amount of the crude pigment. A method for producing the organic pigment composition according to the above. The method for producing an organic pigment composition according to claim 1 or 2, wherein the second step is to mix and heat a crude pigment and water and / or an organic solvent in a large excess volume than the crude pigment. The crude pigment produced in the first step or the crude pigment used in the second step is a crude quinacridone pigment, a crude diketopyrrolopyrrole pigment, a crude benzimidazolone-based azo pigment, a crude perylene pigment, a crude perinone pigment, a crude dioxazine pigment. 3. The organic pigment composition according to claim 1, which is at least one crude pigment selected from the group consisting of crude isoindolinone pigment, crude isoindoline pigment, crude thioindigo pigment, crude quinophthalone pigment, and crude anthraquinone pigment. Manufacturing method. The method for producing an organic pigment composition according to claim 1, wherein the crude pigment produced in the first step or the crude pigment used in the second step is a crude benzimidazolone-based azo pigment. A pigment dispersion comprising the organic pigment composition obtained by the method for producing an organic pigment composition according to any one of claims 1, 2, 3, 4, 5, and 6, and a dispersion medium.