JP3770151B2 - Toner for electrostatic image development - Google Patents

Description

（式中、ＲはＣ₅〜Ｃ₂₅の飽和または不飽和の１価の脂肪族の基を表す。）
【００１５】
また、第２の発明は、上記一般式（１）で表される化合物の含有量が、結着樹脂１００重量部に対し、０．１〜１０重量部であることを特徴とする上記第１の発明の静電荷像現像用トナーである。
【００１６】
また、第３の発明は、上記一般式（１）で表される化合物の体積平均粒子径が、０．５〜４０μｍであることを特徴とする上記第１または２の発明の静電荷像現像用トナーである。
【００１７】
また、第４の発明は、トナーが、正帯電性を有していることを特徴とする上記第１〜３のいずれかの発明の静電荷像現像用トナーである。
【００１８】
また、第５の発明は、トナーが、非磁性トナーであることを特徴とする上記第1〜４のいずれかの発明の静電荷像現像用トナーである。
【００１９】
また、第６の発明は、トナーが、磁性トナーであることを特徴とする上記第1〜４のいずれかの発明の静電荷像現像用トナーである。
【００２０】
また、第７の発明は、構造式（２）のＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ９と下記一般式（３）で表される脂肪酸とを反応させてなる化合物を含有することを特徴とする静電荷像現像用トナーである。
【化４】

（式中、ＲはＣ₅〜Ｃ₂₅の飽和または不飽和の１価の脂肪族の基を表す。）
【００２１】
以下、本発明を更に詳細に説明する。
静電荷像現像用トナーの正帯電性荷電制御剤として良好な、本発明の化合物は、構造式（４）で表される、クリスタルバイオレットを水酸化アルカリ金属を用いてベース化して、構造式（２）のＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９を得た後、さらに、一般式（３）で表される脂肪酸と反応せしめて得られる一般式（１）で表される化合物である。
【化５】

具体的には、５０〜７０℃の硬水にクリスタルバイオレットを少しずつ加えて完全に溶解させ、保温しながら攪拌した後、７〜１５モル％の水酸化アルカリ溶液を少しずつ加えてクリスタルバイオレットのベース化を行う。ベース化はクリスタルバイオレット１モル部に対して水酸化アルカリ溶液１モル部使用される反応であることを考慮すれば良い。ベース化の終点確認としては濾紙に反応液を滴下して、にじみがなくなったところを終点として、ベース化されたことと判断できる。ベース化終点時で水酸化アルカリ溶液の滴下を止め、反応溶液を十分に攪拌した後、吸引濾過を行い、水洗する。水洗後、濾紙上に残った生成物を乾燥機にて水分を除去し乾燥して、Ｃ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９が得られる。
さらに、一般式（３）で表される脂肪酸１モル部を１２０〜１４０℃で溶融させた後、Ｃ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９、１モル部を少量ずつ添加してモル比で１：１の割合で均一に混合する。その後、１５０〜１７０℃に昇温させ十分に攪拌し反応せしめた後、室温になるまで放冷し、本発明の化合物を得ることができる。
【００２２】
本発明の化合物を設計する上では、原料である上記脂肪酸の性質を十分に考慮して選択する必要がある。すなわち、分子量が大きいものは、親油性が強く相溶性、濡れ性に優れ結着樹脂中への分散性、分配性が良好になる傾向がある。一方分子量が小さいものは抵抗が低くなる傾向がある。
また原因は定かではないが、不飽和脂肪酸の場合は、二重結合の数が多いほど正帯電性が弱くなる傾向がある。
【００２３】
また、荷電制御剤においては耐水性と耐油性が良好であることが必要不可欠である。耐水性が悪いと荷電制御剤が高湿下でトナーから溶出してしまい、トナーに良好な帯電を付与することができなくなる。さらに溶出による画像等の汚染を起こしてしまう。一方耐油性が悪いとシリコーンオイルを用いている定着工程等で荷電制御剤が溶出してしまい、定着部材を汚染し、更には複写画像をも汚染してしまう。
耐水性については、５０ｃｃの水に荷電制御剤サンプル５００ｍｇを添加して溶解性を目視確認することにより確認することができる。また耐油性については、５０ｃｃのシリコーンオイルに荷電制御剤サンプル５００ｍｇを添加して溶解性を目視確認することにより確認することができる。本発明の化合物においては、これらの手法にて耐水性、耐油性の確認を行った。
【００２４】
本発明に用いることのできる脂肪酸は炭素原子数が６〜２６個の飽和脂肪酸または不飽和脂肪酸が好ましい。飽和脂肪酸としては、例えば、カプロン酸、カプリル酸、カプリン酸、ラウリン酸、ミリスチン酸、パルミチン酸、ステアリン酸、アラキジン酸、ベヘン酸、リグノセリン酸、セロチン酸等を用いることができる。不飽和脂肪酸としては、例えば、デシレン酸、ドデシレン酸、パルミトレイン酸、オレイン酸、リシノレイン酸、ペトロセリン酸、バクセン酸、リノール酸、リノレン酸、エレオステアリン酸、リカン酸、パリナリン酸、タリリン酸、ガドレイン酸、アラキドン酸、セトレイン酸、エルカ酸、セラコレイン酸等を用いることができる。好ましくは炭素原子数が１６〜２２個の飽和脂肪酸または不飽和脂肪酸が好ましい。
これより正帯電性が強いこと、結着樹脂中への分散性、分配性が良好であること、耐水性、耐油性等の特性を満足するものとしては特にステアリン酸、パルミチン酸、オレイン酸、リノール酸を用いることが好ましい。
一方、炭素原子数が６個よりも小さい吉草酸、プロピオン酸、酢酸等は水に可溶であるため、これらの脂肪酸とＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９とからなる化合物は耐水性が悪く、荷電制御剤として用いることは困難である。
【００２５】
またＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９は良好な正帯電性を示すが、耐油性が悪くトナー用荷電制御剤として使用することが困難である。しかし、炭素原子数が６〜２６個の飽和脂肪酸または不飽和脂肪酸を用いて反応せしめることにより耐水性、耐油性を改善させることができる。ここで得られた本発明の化合物は、耐水性、耐油性ともに共に優れ、非常に正帯電性の安定したものとなる。
【００２６】
本発明の化合物は粉砕機により、粉砕し、所望の粒度分布に調整することにより、より効果的に使用することができる。粉砕機の種類としてはジェットミル等の気流式衝突型粉砕機やターボミル、ＫＴＭ、ＭＶＭ、等の機械式衝撃式粉砕機があげられる。本発明の荷電制御剤として良好な粒度分布は体積平均粒径で０．５〜４０μｍであればよく、より好ましくは１〜２０μｍであることが良い。４０μｍよりも大きい粒径のものが含まれていると、結着樹脂中への荷電制御剤の分散が困難になりトナー中への荷電制御剤の分散ができなくなってしまう。またトナー粒子あたりの荷電制御剤の含有量が偏ってしまいカブリの増加や機内飛散の原因にも繋がってしまう。一方、０．５μｍよりも小さい粒径のものを用いると、結着樹脂中への分散は良好であるものの、荷電制御剤の比表面積が大きくなってしまいトナーに過度の帯電を付与してしまい帯電量が増大し画像濃度低下が生じてしまう。
【００２７】
本発明の化合物の静電荷像現像用トナー中の使用量は、使用する結着樹脂の種類により異なるが、通常、結着樹脂１００重量部に対して０．１〜１０重量部、好ましくは０．５〜５重量部、より好ましくは０．８〜３重量部である。
【００２８】
本発明の静電荷像現像用トナーにおいては、荷電制御剤として、本発明の化合物とともに、トナーの荷電制御の微調整を行う目的で他の荷電制御剤を補助的に用いることもできる。このような荷電制御剤としては、従来からトナーに正帯電性を付与することができることが知られた公知の荷電制御剤であればいずれのものであってもよいが、その中でも、ニグロシン染料や第四級アンモニウム塩が好ましい。
【００２９】
本発明の静電荷像現像用トナーの構成成分としては、上記本発明の荷電制御剤以外に、トナーを構成する公知の材料である、結着樹脂および着色剤が用いられる。磁性トナーを得る場合にはさらに磁性粉体が用いられるが、磁性粉体を用いる場合には、磁性粉体が着色剤としても利用されてもよい。したがって、本発明において、着色剤には磁性粉体も含まれる。静電荷像現像用トナーには、更に必要に応じ離型剤、滑剤、流動性改良剤、研磨剤、導電性付与剤、画像剥離防止剤等が内添または外添される。
【００３０】
本発明のトナーに用いられる結着樹脂としては、具体的にはスチレン系重合体、例えば、ポリスチレン、ポリ−ｐ−クロルスチレン、ポリビニルトルエンなどのスチレンおよびその置換体の単重合体、スチレン−ｐ−クロルスチレン共重合体、スチレン−プロピレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタレン共重合体、スチレン−アクリル系共重合体、スチレン−α−クロルメタアクリル酸メチル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−アクリロニトリル−インデン共重合体、スチレン−ジメチルアミノエチルアクリレート共重合体、スチレンジエチルアミノエチルアクリレート共重合体、スチレン−ブチルアクリレート−ジエチルアミノエチルメタクリレート共重合体等のスチレン系共重合体、架橋されたスチレン系共重合体など；ポリエステル樹脂、例えば、脂肪属ジカルボン酸、芳香属ジカルボン酸、芳香属ジアルコール、ジフェノール類から選択される単量体を構造単位として有するポリエステル樹脂、架橋したポリエステル樹脂など；その他ポリ塩化ビニル、フェノール樹脂、変性フェノール樹脂、マレイン樹脂、ロジン変性マレイン樹脂、ポリ酢酸ビニル、シリコーン樹脂、ポリウレタン樹脂、ポリアミド樹脂、エポキシ樹脂、ポリビニルブチラール、ロジン、変性ロジン、テルペン樹脂、キシレン樹脂、脂肪族または脂肪族炭化水素樹脂、石油樹脂などを挙げることができる。
【００３１】
上記スチレン・アクリル系共重合体に使用されるアクリル系単量体としては、例えば、アクリル酸やメタクリル酸、アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸ドデシル、アクリル酸オクチル、アクリル酸２エチルヘキシル、アクリル酸フェニル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸オクチルなどの（メタ） アクリル酸エステル類が挙げられ、更にはこれと共に用いることができる単量体として、アクリロニトリル、メタクリロニトリル、アクリルアミド、マレイン酸、マレイン酸ブチルなどのマレイン酸ハーフエステル、あるいはジエステル類、酢酸ビニル、塩化ビニル、ビニルメチルエーテル、ビニルエチルエーテル、ビニルプロピルエーテル、ビニルブチルエーテルなどのビニルエーテル類、ビニルメチルケトン、ビニルエチルケトン、ビニルヘキシルケトンなどのビニルケトン類を挙げることができる。
【００３２】
また、上記の架橋したスチレン系重合体を製造するために用いる架橋剤としては、主として不飽和結合を２個以上有する化合物を挙げることができ、具体的には、例えばジビニルベンゼン、ジビニルナフタレンなどの芳香族ジビニル化合物；エチレングリコールジアクリレート、エチレングリコールジメタクリレートなどの不飽和結合を２個以上有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホンなどのジビニル化合物；および不飽和結合を ３個以上有する化合物を、単独であるいは混合して使用することができる。上記架橋剤は、結着樹脂１００重量部に対して、０．０１〜１０重量％、好ましくは０．０５〜５重量％で用いられる。
【００３３】
これらの樹脂は、単独であるいは２種以上を併用して用いることができる。これら樹脂のうち、スチレン系重合体、ポリエステル樹脂は、特に優れた帯電特性を示すため好ましいものである。また、ＧＰＣ（ゲルパーミエーション・クロマトグラフー）により測定される分子量分布で１x １０³ から５x １０⁴ の領域に少なくとも一つのピークを有し、かつ１０⁵ 以上の領域に少なくとも一つのピークあるいはショルダーを有するスチレン系共重合体、更には２種以上の樹脂、例えば前記スチレン樹脂とスチレン−アクリル系共重合体との併用あるいは２種以上のスチレン−アクリル系共重合体の併用などによりこのような分子量分布を有するようにされた樹脂組成物が、トナーの粉砕性、定着性などの点から好ましいものである。
【００３４】
更に、加圧定着方式を用いる場合には、圧力トナー用結着樹脂を使用することができる。このような樹脂としては、例えばポリエチレン、ポリプロピレン、ポリメチレン、ポリウレタンエラストマー、エチレン−エチルアクリレート共重合体、スチレン−イソプレン共重合体、線状飽和ポリエステル、パラフィンおよび他のワックス類を挙げることができる。
【００３５】
本発明の静電荷像現像用トナーにおいて用いることができる着色剤としては、従来トナーの製造において用いられることが知られた着色剤がいずれも使用可能であり、これら着色剤の例としては、脂肪酸金属塩、種々のカーボンブラック、フタロシアニン系、ローダミン系、キナクリドン系、トリアリールメタン系、アントラキノン系、アゾ系、ジアゾ系などの染顔料があげられる。これらは単独で或いは２種以上を混合して使用することができる。
【００３６】
また、本発明の静電荷像現像用トナーにおいて用いられる磁性粉体は、従来磁性トナーの製造において使用されている強磁性の元素を含む合金、化合物等の何れの粉体であってもよい。これら磁性粉体の例としては、マグネタイト、マグヘマイト、フェライト等の酸化鉄または二価金属と酸化鉄との化合物、鉄、コバルト、ニッケルのような金属或いはこれらの金属のアルミニウム、コバルト、銅、鉛、マグネシウム、スズ、亜鉛、アンチモン、ベリリウム、ビスマス、カドミウム、カルシウム、マンガン、セレン、チタン、タングステン、バナジウムのような金属の合金の粉体およびこれらの混合物があげられる。これらの磁性粉体は、平均粒径が０．１〜２μｍ、更には０．１〜０．５μｍ程度のものが好ましい。また、磁性粉体のトナー中の含有量は、熱可塑性樹脂１００質量部に対して、約２０〜２００質量部、好ましくは４０〜１５０質量部である。また、トナーの飽和磁化としては、１５〜３５ｅｍｕ／ｇ（測定磁場 １キロエルステッド）が好ましい。
【００３７】
本発明のトナーは、キャリアと混合して二成分系現像剤として使用することができる。本発明のトナーとともに用いることのできるキャリアとしては、従来公知のキャリアであればいずれであってもよい。使用することができるキャリアとしては、例えば、鉄粉、フェライト粉、ニッケル粉のような磁性粉体やガラスビーズ等、あるいはこれらの表面を樹脂などで処理したものが挙げられる。キャリア表面を被覆する樹脂としては、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共重合体、メタクリル酸エステル共重合体、フッ素含有樹脂、シリコーン含有樹脂、ポリアミド樹脂、アイオノマー樹脂、ポリフェニレンサルファイド樹脂など、あるいはこれらの混合物があげられる。これらのなかでは、スペントトナーの形成が少ないためフッ素含有樹脂、シリコーン含有樹脂が特に好ましい。
【００３８】
本発明の静電荷像現像用トナーの粒径は、重量平均粒径が１〜３０μｍ、好ましくは３〜１５μｍであることが望ましい。特に、５μｍ以下の粒径を有するトナー粒子が１２〜６０個数％含有され、８〜１２．７μｍの粒径を有するトナー粒子が１〜３３個数％含有され、１６μｍ以上の粒径を有するトナー粒子が２．０重量％以下含有され、トナーの重量平均粒径が４〜１０μｍであるものが、現像特性のうえからはより好ましい。なお、トナーの粒度分布測定は、例えばコールターカウンターを用いて測定することができる。
【００３９】
本発明のトナーは、さらに必要に応じて離型剤、滑剤、流動性改良剤、研磨剤、導電性付与剤、画像剥離防止剤等のトナーの製造にあたり使用されている公知の添加剤を内添、あるいは外添することができるが、これら添加剤の例としては、離型剤としては、例えば低分子量ポリエチレン、低分子量ポリプロピレン、マイクロクリスタリンワックス、カルナバワックス、サゾールワックス、パラフィンワックスなどのワックス状物質があげられ、これらは通常０．５〜５重量％程度の量でトナー中に加えられる。また、滑剤としては、ポリフッ化ビニリデン、ステアリン酸亜鉛などが、流動性改良剤としては、乾式法あるいは湿式法で製造したシリカ、酸化アルミニウム、酸化チタン、珪素アルミニウム共酸化物、珪素チタン共酸化物およびこれらを疎水性化処理したものなどが、研磨剤としては窒化珪素、酸化セリウム、炭化ケイ素、チタン酸ストロンチウム、タングステンカーバイド、炭酸カルシウムおよびこれらを疎水化処理したものなどが、導電性付与剤としてはカーボンブラック、酸化スズなどがあげられる。また、ポリビニリデンフルオライドなどのフッ素含有重合体の微粉末は、流動性、研磨性、帯電安定性などの点から好ましいものである。
【００４０】
なお、本発明においては、疎水化処理されたシリカ、疎水化処理された酸化アルミニウム、疎水化処理された珪素アルミニウム共酸化物あるいは疎水化処理された珪素チタン共酸化物微粉体を外添剤として用いることが好ましい。シリカ微粉体の疎水化処理としては、シリコーンオイル、ジクロロジメチルシラン、ヘキサメチルジシラザン、テトラメチルジシラザンなどのシランカップリング剤による処理等があげられる。また、ブローオフ法により測定したときに、鉄粉キャリアに対してプラスのトリボ電荷を有する正帯電性のシリカを用いることが好ましい。この正帯電性のシリカを得るためには、側鎖に窒素原子を少なくとも１つ有するオルガノ基を有するシリコーンオイル、あるいは窒素含有のシランカップリング剤で処理すればよい。疎水化処理されたシリカ微粉体の使用量は、現像剤重量あたり、０．０１〜２０％、好ましくは０．０３〜５％である。
【００４１】
本発明に係るトナーは、従来から公知のトナーの製造方法を用いて製造することができる。一般的には、上述したようなトナー構成材料を、ボールミル、ヘンシェルミキサーなどの混合機により充分混合したのち、熱ロールニーダー、一軸あるいは二軸のエクストルーダーなどの熱混練機を用いて良く混練し、冷却固化後、ハンマーミルなどの粉砕機を用いて機械的に粗粉砕し、次いでジェットミルなどにより微粉砕した後、分級する方法が好ましい。さらに分級した後、外添剤をヘンシェルミキサー等の混合機を用いて十分に混合して用いることが好ましい。
しかし、トナーの製造法はこの方法に限られるものではなく、結着樹脂溶液中に他のトナー構成材料を分散した後、噴霧乾燥する方法、所謂マイクロカプセル法によりトナーを製造する方法、結着樹脂を形成する単量体に所定材料を混合し、乳化あるいは懸濁重合を行いトナーを得る重合法トナー製造法など他の方法も任意に採用することができる。
【００４２】
本発明の静電荷像現像用トナーは、従来公知の電子写真、静電記録あるいは静電印刷法などを利用して乾式トナー画像を形成するいずれの方法あるいは装置に対しても好ましい現像用トナーとして使用することができる。
【００４３】
【実施例】
以下、本発明を実施例によりさらに具体的に説明するが、本発明の態様はこれらの実施例に限定されるものではない。
【００４４】
荷電制御剤製造例
製造例１
６０℃の硬水８０００gにクリスタルバイオレット４００gを少しずつ加えて溶解した。１５分間保温攪拌した後、１０％水酸化ナトリウム水溶液を約３０分かけて加え、クリスタルバイオレットをベース化した。ベース化の判断はＮｏ．２濾紙に点滴して反応液のにじみが無くなったところを終点とした。このときベース化に用いた水酸化ナトリウム水溶液は３８５gであった。
ベース化後、５分間攪拌した後吸引濾過を行い、水２５００gで水洗した後、濾過残留物を５０℃で１８時間乾燥し、その後７０℃で５時間乾燥し２９６ｇのＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９を得た。
更に、ステンレストレイにステアリン酸２１３．０ｇを入れ、ヒーターで１３０℃にステンレストレイを加熱し、ステアリン酸を溶解させた。その後、Ｃ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９、２９２．０ｇを少量づつ加え、均一に混合した。ヒーター温度を１６０℃に設定した後、１０分間攪拌した後室温になるまで放冷した。後、粉砕機（ジェットミル）にて粉砕し体積平均粒径７．５μｍの荷電制御剤１を得た。
【化６】

【００４５】
製造例２
ステアリン酸を用いる代わりにパルミチン酸を用いる以外は製造例１と同様にして平均粒径７．２μｍの荷電制御剤２を得た。
【化７】

【００４６】
製造例３
ステアリン酸を用いる代わりにオレイン酸を用いる以外は製造例１と同様にして平均粒径７．３μｍの荷電制御剤３を得た。
【化８】

【００４７】
製造例４
ステアリン酸を用いる代わりにリノール酸を用いる以外は製造例１と同様にして平均粒径７．４μｍの荷電制御剤４を得た。
【化９】

【００４８】
製造例５
ステアリン酸を用いる代わりにカプロン酸を用いる以外は製造例１と同様にして平均粒径７．６μｍの荷電制御剤５を得た。
【化１０】

【００４９】
製造例６
ステアリン酸を用いる代わりにセロチン酸を用いる以外は製造例１と同様にして平均粒径７．５μｍの荷電制御剤６を得た。
【化１１】

【００５０】
比較製造例１
製造例１で得られたＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ ９を粉砕機（ジェットミル）にて平均粒径７．５μｍに粉砕した。
比較製造例２
ステアリン酸を用いる代わりに吉草酸を用いる以外は製造例１と同様にして平均粒径７．５μｍの荷電制御剤７を得た。
【００５１】
【化１２】

【００５２】
【表１】

【００５３】
実施例１
スチレン−アクリル酸ｎブチル共重合体 ８７．５重量部
カーボンブラック ８重量部
荷電制御剤１ ２重量部
ポリプロピレンワックス ２重量部
ポリエチレンワックス ０．５重量部
上記材料をヘンシェルミキサーで均一に混合した後、二軸加熱混練機に投入し混練、押し出されてきたものを室温で冷却し、ハンマーミルで粗粉砕してチップを得た。次いで、これをターボミル粉砕機で微粉砕し、分級機に導き、１１．５μｍに平均粒度を有する部分をトナー用微粉末として取り出した。次いで、このトナー用微粉末１００重量部に対し、正帯電性疎水性シリカ微粉体０．３重量部、およびタングステンカーバイド微粉体０．４重量部を添加し、ヘンシェルミキサーで混合して正帯電性非磁性トナーを得た。得られたトナー４部と平均粒径１００μｍのシリコーン樹脂コートのキャリア１００部とをボールミルを用いて混合し現像剤を作製した。次にこのトナーと現像剤を用いて、市販の複写機ＦＰ７７３５（松下電送社製）により、高温高湿（３０℃、８５％ＲＨ）の環境下で実写試験を行なった。この際トナーは加熱劣化の確認を促進して見極めるべく乾燥機中に５０℃、７２時間の条件にて加熱した。得られたトナーおよび現像剤を用いたところ、５万枚実写後でもカブリは少なく、画像濃度も安定しており、機内のトナー飛散、画像汚れも見られなかった。初期および５万枚複写時の画像濃度は各々１．４２および１．４１であり、また初期および５万枚複写時のカブリは各々０．７および０．６であった。
【００５４】
なお、画像濃度はマクベス光度計を用いて行い、１．３５以上の濃度であればよい。なお、カブリはフォトボルトにて、反射率を測定することにより行った。１．２％以下が良好な値である。 また、トナーの機内飛散は、複写機の転写チャージャー上に飛散トナーが存在するか否かを確認することにより行った。転写チャージャー上にトナー飛散がみられる場合、これに伴い画像汚れが発生する。
【００５５】
実施例２〜６、および比較例１〜４
実施例１に用いた荷電制御剤１を用いる代わりに、表２に記載の荷電制御剤を用いることを除き、実施例１と同様の評価を行った。結果を表３に示す。
【００５６】
【表２】

【００５７】
実施例７
スチレン−アクリル酸ｎブチル共重合体 ５５．５重量部
磁性酸化鉄 ４０重量部
荷電制御剤１ ２重量部
ポリプロピレンワックス ２重量部
パラフィンワックス ０．５重量部
をヘンシェルミキサーで混合した後、二軸加熱混練機に投入し、混練、押し出されてきたものを室温で冷却し、ハンマーミルで粗粉砕してチップを得た。次いで、これをターボミル粉砕機で微粉砕し、分級機に導き、１０μｍに平均粒度を有する部分をトナー用微粉末として取り出した。このトナー用微粉末１００重量部に対し、シリコーンオイルにて疎水化処理されたシリカ０．２５重量部を加え、ヘンシェルミキサーで混合し正帯電性磁性トナーを得た後、このトナーの加熱経時変化を調べた。加熱経時変化の試験は、トナーを５０℃の乾燥機中に７２時間放置して加熱劣化を促進させた後、市販の複写機（キヤノン社製複写機 ＮＰ４１４５）を用いて、２３℃、５０ＲＨの環境条件下、５万枚の連続実写を行うことによった。初期および５万枚複写時の画像濃度は各々１．４４および１．３９であり、また初期および５万枚複写時のカブリは各々０．５および０．７で特に変化はなかった。さらに、５万枚複写後におけるトナー粒子の機内飛散はなく、得られた画像の汚れもなかった。
【００５８】
実施例８〜１２、および比較例５〜８
実施例７に用いた荷電制御剤１を用いる代わりに、表３に記載の荷電制御剤を用いることを除き、実施例７と同様の評価を行った。結果を表３に示す。
【００５９】
【表３】

【００６０】
【発明の効果】
以上述べたように、本発明の化合物を静電荷像現像用トナーの荷電制御剤として用いることにより、荷電制御剤が均一に分散された静電荷像現像用トナーを得ることができ、このトナーは初期から良好な画像濃度を有しカブリのない複写画像を得ることができると共に多数枚の複写を重ねた場合にも画像濃度の低下はなく、また、本発明の静電荷像現像用トナーは加熱経時変化もなく、市販するまであるいは購入後のトナーの貯蔵時、あるいは輸送時などにおける加熱ストレスによる特性変化のない、良好なトナーを得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic charge image developing toner used for developing an electrostatic latent image in an electrophotographic copying machine, a laser beam printer or the like in which an image is formed using an electrophotographic method, an electrostatic recording method, or the like. .
[0002]
[Prior art]
Conventionally, as a method for developing an electrostatic latent image formed on an electrostatic image carrier such as an electrophotographic photosensitive member or an electrostatic recording member, it can be roughly divided into liquid development in which fine toner is dispersed in an electrically insulating liquid. Two methods are known: a method using an agent (wet development method) and a method using a toner in which a colorant or magnetic powder is dispersed in a binder resin (dry development method). In the dry development method, a method using a two-component developer composed of carrier particles and a toner and a method using a one-component developer composed only of a toner are known.
[0003]
The toner for developing an electrostatic image used in these dry development methods usually uses a styrene resin or a polyester resin as a binder resin, kneaded with a colorant such as a dye or a pigment, cooled, and then pulverized. It is manufactured through a classification process. The particle diameter of the toner for developing an electrostatic charge image usually has an average particle diameter of about 1 to 30 μm. In the case of magnetic toner, magnetic powder such as magnetite is further used. Further, as the carrier particles used in the two-component developer, glass beads, iron powder, ferrite, magnetite and the like, which are coated with a resin if necessary, are used.
[0004]
The electrostatic image developing toner as described above is required to hold positive or negative charges depending on the polarity of the electrostatic latent image to be developed. In order to retain the charge in the toner for developing an electrostatic image, it is possible to use triboelectric charging properties such as a binder resin and a colorant which are toner components. However, this alone usually has a small charge amount and a stable polarity. Therefore, an image obtained by development is easily fogged and unclear. For this reason, a material called a charge control agent is generally added to the toner in order to impart desirable charging characteristics to the toner.
[0005]
As a typical example of a conventional charge control agent, for example, a basic dye such as a triarylmethane dye or a nigrosine dye (Japanese Patent Publication No. 48-25669), or the like, which gives positive chargeability to a toner, Electron-donating substances such as quaternary ammonium salts (Japanese Patent Laid-Open No. 57-119364), organic tin oxide (Japanese Patent Publication No. 57-29704), polymers having amino groups, and the like also impart negative chargeability to the toner. Examples thereof include metal-containing dyes such as metal complexes of monoazo dyes, aromatic hydroxycarboxylic acid metal compounds, and chromium-containing organic dyes (copper phthalocyanine green, chromium-containing monoazo dyes).
[0006]
In recent years, an electrophotographic copier or a photoconductor using an organic photoconductor is often seen as a photoconductor, and a positively chargeable toner is required as a developer for a copier using the organic photoconductor. . However, many of the positively chargeable charge control agents used for producing the positively chargeable toner are hydrophilic, and the charge amount tends to decrease under high humidity conditions, while the charge amount decreases under high humidity conditions. Many that do not have the problem that the charge amount becomes unnecessarily high under low humidity. In addition, positively chargeable charge control agents are often deteriorated by heat when the toner is left at a high temperature for a long period of time, resulting in an increase in fog and scattering in the apparatus. For example, nigrosine dye has high charging performance, but the positive chargeability is very strong, so the toner charge amount becomes excessively high and the image density may decrease as the number of copies increases. It is difficult to obtain a material that sufficiently satisfies the conditions required as an agent. Further, the quaternary ammonium salt has a low charge imparting ability, and fogging and scattering in the machine may be observed as the number of copies is increased under high temperature and high humidity. Furthermore, deterioration due to leaving at high temperature and high humidity often occurs.
[0007]
In addition, triarylmethane dyes such as methyl violet, crystal violet, and crystal violet base have excellent positive charge properties, but have problems with water resistance or oil resistance and are difficult to use practically as toners. There are many. When the water resistance is poor, the environmental stability is deteriorated, and the charge amount is lowered particularly under high humidity, resulting in an increase in fog and scattering in the machine. Further, these dyes are eluted from the toner and cause image contamination. On the other hand, when the oil resistance is poor, when silicone oil or the like is used in the fixing unit, when the toner is melted, these dyes are eluted and cause color contamination of the fixing unit and the image.
[0008]
[Problems to be solved by the invention]
Thus, triarylmethane dyes are relatively excellent positively chargeable charge control agents, but have various problems. Solving these problems, excellent in water resistance and oil resistance, moderately high charge amount, low dependency on temperature and humidity during development, no deterioration of toner characteristics due to standing at high temperature and high humidity, binder resin There is a need for a positively chargeable charge control agent having good dispersibility with respect to toner, excellent development characteristics, and excellent durability, and a positively chargeable toner including the same.
[0009]
An object of the present invention is to provide a positively chargeable electrostatic image developing toner having excellent characteristics that does not have the above-described problems, that is, a triboelectric charge amount between a toner and a carrier and a toner carrier such as a toner and a developing sleeve. It is an object of the present invention to provide a positively chargeable toner for developing an electrostatic image capable of forming a stable and stable toner image without being affected by temperature and humidity.
[0010]
Another object of the present invention is to provide a toner for developing a positively chargeable electrostatic charge image that has a stable triboelectric charge amount even when the number of copies increases, and that does not generate fog and scatter toner inside the machine.
[0011]
Another object of the present invention is to provide a positively chargeable electrostatic charge image developing toner in which a charge control agent is uniformly dispersed in the toner and a clear image free from fogging can be formed. .
[0012]
Furthermore, an object of the present invention is to provide a positively chargeable electrostatic image developing toner that does not deteriorate the toner characteristics due to thermal stress during toner storage.
[0013]
As a result of intensive studies, the present inventors have found that C.I. I. It has been found that the above object can be achieved by using a compound comprising Solvent Violet 9 and a saturated or unsaturated fatty acid having 6 to 26 carbon atoms as a charge control agent, and the present invention has been achieved.
[0014]
[Means for Solving the Problems]
That is, according to the first invention, in the electrostatic image developing toner containing at least a binder resin, a colorant, and a charge control agent, the charge control agent contains a compound represented by the following general formula (1). The present invention relates to a toner for developing an electrostatic charge image.
[Chemical 3]

(Where R is C _Five ~ C _{twenty five} Represents a saturated or unsaturated monovalent aliphatic group. )
[0015]
According to a second aspect of the invention, the content of the compound represented by the general formula (1) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The electrostatic charge image developing toner according to the present invention.
[0016]
The third aspect of the invention is the electrostatic charge image development of the first or second aspect of the invention, wherein the compound represented by the general formula (1) has a volume average particle diameter of 0.5 to 40 μm. Toner.
[0017]
A fourth invention is the electrostatic image developing toner according to any one of the first to third inventions, wherein the toner has a positive chargeability.
[0018]
A fifth invention is the electrostatic image developing toner according to any one of the first to fourth inventions, wherein the toner is a non-magnetic toner.
[0019]
A sixth invention is the electrostatic image developing toner according to any one of the first to fourth inventions, wherein the toner is a magnetic toner.
[0020]
The seventh invention relates to C.I. of the structural formula (2). I. An electrostatic image developing toner comprising a compound obtained by reacting Solvent Violet 9 and a fatty acid represented by the following general formula (3).
[Formula 4]

(Where R is C _Five ~ C _{twenty five} Represents a saturated or unsaturated monovalent aliphatic group. )
[0021]
Hereinafter, the present invention will be described in more detail.
The compound of the present invention, which is suitable as a positively chargeable charge control agent for an electrostatic charge image developing toner, is obtained by basing crystal violet represented by the structural formula (4) by using an alkali metal hydroxide. 2) C.I. I. After obtaining Solvent Violet 9, it is a compound represented by general formula (1) obtained by further reacting with a fatty acid represented by general formula (3).
[Chemical formula 5]

Specifically, crystal violet is added little by little to hard water at 50 to 70 ° C., dissolved completely, stirred while keeping warm, and then a base solution of crystal violet is added by adding 7 to 15 mol% alkali hydroxide solution little by little. To do. It may be considered that the base formation is a reaction in which 1 mol part of an alkali hydroxide solution is used with respect to 1 mol part of crystal violet. In order to confirm the end point of the base, it can be determined that the base has been made with the reaction solution dropped on the filter paper and the point where the bleeding disappeared as the end point. At the end of the base formation, the dropping of the alkali hydroxide solution is stopped and the reaction solution is sufficiently stirred, and then suction filtration is performed, followed by washing with water. After washing with water, the product remaining on the filter paper was dried by removing moisture with a dryer. I. Solvent Violet 9 is obtained.
Furthermore, after melting 1 mol part of the fatty acid represented by the general formula (3) at 120 to 140 ° C., C.I. I. Solvent Violet 9, 1 mol part is added little by little, and it mixes uniformly by the ratio of 1: 1 by molar ratio. Then, after heating up to 150-170 degreeC and fully stirring and making it react, it stood to cool to room temperature, and the compound of this invention can be obtained.
[0022]
In designing the compound of the present invention, it is necessary to select the properties of the fatty acid as a raw material with sufficient consideration. That is, those having a large molecular weight have strong lipophilicity, excellent compatibility and wettability, and tend to have good dispersibility and distribution in the binder resin. On the other hand, those having a low molecular weight tend to have low resistance.
The cause is not clear, but in the case of unsaturated fatty acids, the positive chargeability tends to decrease as the number of double bonds increases.
[0023]
In addition, it is essential for the charge control agent to have good water resistance and oil resistance. If the water resistance is poor, the charge control agent will be eluted from the toner under high humidity, and it will not be possible to impart good charge to the toner. Furthermore, the image and the like are contaminated by elution. On the other hand, when the oil resistance is poor, the charge control agent is eluted in a fixing process using silicone oil, etc., contaminating the fixing member and further contaminating the copy image.
The water resistance can be confirmed by adding 500 mg of the charge control agent sample to 50 cc of water and visually confirming the solubility. Oil resistance can be confirmed by adding 500 mg of a charge control agent sample to 50 cc of silicone oil and visually confirming the solubility. In the compounds of the present invention, water resistance and oil resistance were confirmed by these methods.
[0024]
The fatty acid that can be used in the present invention is preferably a saturated or unsaturated fatty acid having 6 to 26 carbon atoms. Examples of saturated fatty acids that can be used include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and serotic acid. Examples of the unsaturated fatty acid include decylene acid, dodecylene acid, palmitoleic acid, oleic acid, ricinoleic acid, petrothelic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, licanoic acid, parinaric acid, taliphosphoric acid, gadole Acid, arachidonic acid, cetreic acid, erucic acid, ceracoleic acid and the like can be used. Saturated fatty acids having 16 to 22 carbon atoms or unsaturated fatty acids are preferred.
As positive chargeability, dispersibility in the binder resin, good dispersibility, water resistance, oil resistance, and other properties satisfying characteristics such as stearic acid, palmitic acid, oleic acid, It is preferable to use linoleic acid.
On the other hand, valeric acid, propionic acid, acetic acid and the like having less than 6 carbon atoms are soluble in water. I. The compound consisting of Solvent Violet 9 has poor water resistance and is difficult to use as a charge control agent.
[0025]
In addition, C.I. I. Solvent Violet 9 exhibits good positive chargeability, but has poor oil resistance and is difficult to use as a charge control agent for toner. However, water resistance and oil resistance can be improved by reacting with a saturated or unsaturated fatty acid having 6 to 26 carbon atoms. The compound of the present invention obtained here is excellent in both water resistance and oil resistance, and is very stable in positive chargeability.
[0026]
The compound of the present invention can be used more effectively by pulverizing with a pulverizer and adjusting to a desired particle size distribution. Examples of the type of pulverizer include an airflow type impact pulverizer such as a jet mill and a mechanical impact pulverizer such as a turbo mill, KTM, and MVM. A good particle size distribution as the charge control agent of the present invention may be a volume average particle size of 0.5 to 40 μm, more preferably 1 to 20 μm. If the particle size is larger than 40 μm, it is difficult to disperse the charge control agent in the binder resin, and the charge control agent cannot be dispersed in the toner. In addition, the content of the charge control agent per toner particle is biased, leading to an increase in fog and scattering in the apparatus. On the other hand, when a particle having a particle size smaller than 0.5 μm is used, although the dispersion in the binder resin is good, the specific surface area of the charge control agent is increased and the toner is excessively charged. The charge amount increases and the image density decreases.
[0027]
The amount of the compound of the present invention used in the toner for developing an electrostatic charge image varies depending on the type of binder resin used, but is usually 0.1 to 10 parts by weight, preferably 0 to 100 parts by weight of the binder resin. 0.5 to 5 parts by weight, more preferably 0.8 to 3 parts by weight.
[0028]
In the toner for developing an electrostatic charge image of the present invention, as the charge control agent, another charge control agent can be used in addition to the compound of the present invention for the purpose of finely adjusting the charge control of the toner. Such a charge control agent may be any known charge control agent that has been conventionally known to be capable of imparting positive chargeability to toners. Quaternary ammonium salts are preferred.
[0029]
As a constituent component of the toner for developing an electrostatic image of the present invention, a binder resin and a colorant, which are known materials constituting the toner, are used in addition to the charge control agent of the present invention. In the case of obtaining a magnetic toner, a magnetic powder is further used. However, in the case of using a magnetic powder, the magnetic powder may be used as a colorant. Accordingly, in the present invention, the colorant includes magnetic powder. The toner for developing an electrostatic charge image is further internally or externally added with a release agent, a lubricant, a fluidity improver, an abrasive, a conductivity imparting agent, an image peeling preventing agent, and the like as necessary.
[0030]
Specific examples of the binder resin used in the toner of the present invention include styrene polymers, for example, styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and homopolymers of substitution products thereof, styrene-p. -Chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic copolymer, styrene-α-chloromethacrylic acid methyl copolymer Styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Styrene-dimethylaminoethyl acrylate Styrene copolymers such as styrene-diethylaminoethyl acrylate copolymer, styrene-butyl acrylate-diethylaminoethyl methacrylate copolymer, cross-linked styrene copolymer, etc .; polyester resins such as aliphatic dicarboxylic acid, aromatic Polyester resins having monomers selected from the group of dicarboxylic acids, aromatic dialcohols and diphenols as structural units, crosslinked polyester resins, etc .; other polyvinyl chloride, phenol resins, modified phenol resins, maleic resins, rosin modified Malee resin, polyvinyl acetate, silicone resin, polyurethane resin, polyamide resin, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, xylene resin, aliphatic or aliphatic hydrocarbon resin, petroleum resin, etc. Can be mentioned.
[0031]
Examples of the acrylic monomer used in the styrene / acrylic copolymer include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, and acrylic acid. (Meth) acrylic acid esters such as 2-ethylhexyl, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, and the like. Furthermore, as a monomer that can be used with this, acrylonitrile, Maleic acid half esters such as methacrylonitrile, acrylamide, maleic acid, butyl maleate, or diesters, vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl butyl ether And vinyl ethers such as vinyl methyl ketone, vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone and the like.
[0032]
Examples of the crosslinking agent used for producing the above-mentioned crosslinked styrene-based polymer include compounds having two or more unsaturated bonds, specifically, for example, divinylbenzene, divinylnaphthalene and the like. Aromatic divinyl compounds; carboxylic acid esters having two or more unsaturated bonds such as ethylene glycol diacrylate and ethylene glycol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; One or more compounds can be used alone or in combination. The crosslinking agent is used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on 100 parts by weight of the binder resin.
[0033]
These resins can be used alone or in combination of two or more. Of these resins, styrene-based polymers and polyester resins are preferable because they exhibit particularly excellent charging characteristics. The molecular weight distribution measured by GPC (gel permeation chromatography) is 1 × 10. ^Three To 5x10 ^Four And at least one peak in the region ^Five A styrene copolymer having at least one peak or shoulder in the above region, and further two or more resins, for example, a combination of the styrene resin and a styrene-acrylic copolymer or two or more styrene-acrylic copolymers. A resin composition having such a molecular weight distribution by using a copolymer or the like is preferable from the viewpoint of the pulverization property and fixing property of the toner.
[0034]
Further, when a pressure fixing method is used, a binder resin for pressure toner can be used. Examples of such a resin include polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin, and other waxes.
[0035]
As the colorant that can be used in the toner for developing an electrostatic charge image of the present invention, any colorant known to be used in the production of conventional toners can be used. Examples of these colorants include fatty acids. Examples thereof include metal salts, various carbon blacks, phthalocyanine series, rhodamine series, quinacridone series, triarylmethane series, anthraquinone series, azo series and diazo series. These can be used alone or in admixture of two or more.
[0036]
Further, the magnetic powder used in the toner for developing an electrostatic charge image of the present invention may be any powder such as an alloy or a compound containing a ferromagnetic element conventionally used in the production of a magnetic toner. Examples of these magnetic powders include iron oxides such as magnetite, maghemite and ferrite, or compounds of divalent metals and iron oxides, metals such as iron, cobalt and nickel or aluminum, cobalt, copper and lead of these metals. , Magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium metal alloy powders and mixtures thereof. These magnetic powders preferably have an average particle size of about 0.1 to 2 μm, more preferably about 0.1 to 0.5 μm. Further, the content of the magnetic powder in the toner is about 20 to 200 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the thermoplastic resin. Further, the saturation magnetization of the toner is preferably 15 to 35 emu / g (measuring magnetic field: 1 kilo-Oersted).
[0037]
The toner of the present invention can be mixed with a carrier and used as a two-component developer. The carrier that can be used together with the toner of the present invention may be any conventionally known carrier. Examples of the carrier that can be used include magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, and the like, or those whose surfaces are treated with a resin or the like. Examples of the resin covering the carrier surface include styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, acrylic acid ester copolymer, methacrylic acid ester copolymer, fluorine-containing resin, silicone-containing resin, and polyamide. Examples thereof include a resin, an ionomer resin, a polyphenylene sulfide resin, and a mixture thereof. Among these, fluorine-containing resins and silicone-containing resins are particularly preferable because they hardly form spent toner.
[0038]
As for the particle diameter of the toner for developing an electrostatic charge image of the present invention, the weight average particle diameter is 1 to 30 μm, preferably 3 to 15 μm. In particular, toner particles having a particle size of 5 μm or less are contained in 12 to 60% by number, toner particles having a particle size of 8 to 12.7 μm are contained in 1 to 33% by number, and toner particles having a particle size of 16 μm or more. Is more preferably 2.0 wt% or less, and the toner has a weight average particle diameter of 4 to 10 μm from the viewpoint of development characteristics. The toner particle size distribution can be measured using, for example, a Coulter counter.
[0039]
The toner of the present invention may further contain known additives used in the production of toners such as a release agent, a lubricant, a fluidity improver, an abrasive, a conductivity imparting agent, and an image peeling prevention agent, if necessary. Examples of these additives include, for example, waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax, and paraffin wax. These are usually added to the toner in an amount of about 0.5 to 5% by weight. Also, as the lubricant, polyvinylidene fluoride, zinc stearate, etc., as the fluidity improver, silica, aluminum oxide, titanium oxide, silicon aluminum co-oxide, silicon titanium co-oxide produced by the dry method or wet method And those obtained by hydrophobizing these, and as abrasives, silicon nitride, cerium oxide, silicon carbide, strontium titanate, tungsten carbide, calcium carbonate, and those hydrophobized by these as conductivity imparting agents. Examples include carbon black and tin oxide. In addition, fine powders of fluorine-containing polymers such as polyvinylidene fluoride are preferable from the viewpoint of fluidity, abrasiveness, charge stability, and the like.
[0040]
In the present invention, hydrophobized silica, hydrophobized aluminum oxide, hydrophobized silicon aluminum co-oxide or hydrophobized silicon titanium co-oxide fine powder is used as an external additive. It is preferable to use it. Examples of the hydrophobization treatment of the silica fine powder include treatment with a silane coupling agent such as silicone oil, dichlorodimethylsilane, hexamethyldisilazane, tetramethyldisilazane, and the like. Moreover, it is preferable to use positively-charged silica having a positive tribo-charge relative to the iron powder carrier when measured by the blow-off method. In order to obtain this positively chargeable silica, it may be treated with a silicone oil having an organo group having at least one nitrogen atom in the side chain, or a nitrogen-containing silane coupling agent. The used amount of the hydrophobized silica fine powder is 0.01 to 20%, preferably 0.03 to 5%, per developer weight.
[0041]
The toner according to the present invention can be manufactured using a conventionally known toner manufacturing method. In general, the above-described toner constituent materials are sufficiently mixed by a mixer such as a ball mill or a Henschel mixer, and then kneaded thoroughly using a thermal kneader such as a hot roll kneader, a uniaxial or biaxial extruder. After cooling and solidifying, a method of coarsely pulverizing mechanically using a pulverizer such as a hammer mill, then finely pulverizing with a jet mill or the like and then classifying is preferable. After further classification, it is preferable to use the external additive by sufficiently mixing it with a mixer such as a Henschel mixer.
However, the method for producing the toner is not limited to this method, and the method for producing the toner by the so-called microcapsule method, the method of dispersing the toner after dispersing other toner constituent materials in the binder resin solution, and the binder, Other methods such as a polymerization toner manufacturing method in which a predetermined material is mixed with a monomer forming a resin, and emulsion or suspension polymerization is performed to obtain a toner can be arbitrarily employed.
[0042]
The electrostatic image developing toner of the present invention is a preferred developing toner for any method or apparatus for forming a dry toner image using a conventionally known electrophotography, electrostatic recording or electrostatic printing method. Can be used.
[0043]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the embodiment of the present invention is not limited to these examples.
[0044]
Examples of manufacturing charge control agents
Production Example 1
400 g of crystal violet was added little by little to 8000 g of hard water at 60 ° C. and dissolved. After stirring for 15 minutes, a 10% aqueous sodium hydroxide solution was added over about 30 minutes to base crystal violet. Judgment of the base is No. 2 The point at which the reaction solution disappeared after instilling on the filter paper was defined as the end point. At this time, the amount of the aqueous sodium hydroxide used for the base was 385 g.
After base formation, the mixture was stirred for 5 minutes, filtered with suction, washed with 2500 g of water, and the filter residue was dried at 50 ° C. for 18 hours, then dried at 70 ° C. for 5 hours and 296 g of C.I. I. Solvent Violet 9 was obtained.
Furthermore, 213.0 g of stearic acid was placed in the stainless steel tray, and the stainless steel tray was heated to 130 ° C. with a heater to dissolve the stearic acid. Thereafter, C.I. I. Solvent Violet 9, 292.0 g was added in small portions and mixed uniformly. The heater temperature was set to 160 ° C., stirred for 10 minutes, and then allowed to cool to room temperature. Then, it grind | pulverized with the grinder (jet mill), and the charge control agent 1 with a volume average particle diameter of 7.5 micrometers was obtained.
[Chemical 6]

[0045]
Production Example 2
A charge control agent 2 having an average particle diameter of 7.2 μm was obtained in the same manner as in Production Example 1 except that palmitic acid was used instead of stearic acid.
[Chemical 7]

[0046]
Production Example 3
A charge control agent 3 having an average particle size of 7.3 μm was obtained in the same manner as in Production Example 1 except that oleic acid was used instead of stearic acid.
[Chemical 8]

[0047]
Production Example 4
A charge control agent 4 having an average particle size of 7.4 μm was obtained in the same manner as in Production Example 1 except that linoleic acid was used instead of stearic acid.
[Chemical 9]

[0048]
Production Example 5
A charge control agent 5 having an average particle size of 7.6 μm was obtained in the same manner as in Production Example 1 except that caproic acid was used instead of stearic acid.
[Chemical Formula 10]

[0049]
Production Example 6
A charge control agent 6 having an average particle size of 7.5 μm was obtained in the same manner as in Production Example 1 except that serotic acid was used instead of stearic acid.
Embedded image

[0050]
Comparative production example 1
C.I obtained in Production Example 1 I. Solvent Violet 9 was pulverized to an average particle size of 7.5 μm with a pulverizer (jet mill).
Comparative production example 2
A charge control agent 7 having an average particle size of 7.5 μm was obtained in the same manner as in Production Example 1 except that valeric acid was used instead of stearic acid.
[0051]
Embedded image

[0052]
[Table 1]

[0053]
Example 1
87.5 parts by weight of styrene-n-butyl acrylate copolymer
8 parts by weight of carbon black
Charge control agent 1 2 parts by weight
2 parts by weight of polypropylene wax
Polyethylene wax 0.5 parts by weight
The above materials were uniformly mixed with a Henschel mixer, then put into a biaxial heating kneader, kneaded and extruded, cooled at room temperature, and coarsely ground with a hammer mill to obtain chips. Subsequently, this was finely pulverized by a turbo mill, and led to a classifier, and a portion having an average particle size of 11.5 μm was taken out as a fine powder for toner. Next, 0.3 part by weight of positively chargeable hydrophobic silica fine powder and 0.4 part by weight of tungsten carbide fine powder are added to 100 parts by weight of the fine powder for toner and mixed with a Henschel mixer to be positively charged. A non-magnetic toner was obtained. 4 parts of the obtained toner and 100 parts of a silicone resin-coated carrier having an average particle diameter of 100 μm were mixed using a ball mill to prepare a developer. Next, using this toner and developer, a real copying test was performed in a high-temperature and high-humidity environment (30 ° C., 85% RH) using a commercially available copying machine FP7735 (manufactured by Matsushita Electric Express Co., Ltd.). At this time, the toner was heated in a dryer at 50 ° C. for 72 hours in order to promote confirmation of heat deterioration. When the obtained toner and developer were used, even after 50,000 sheets were actually photographed, fog was small, the image density was stable, and toner scattering and image smearing in the machine were not observed. The image densities at the initial and 50,000-sheet copying were 1.42 and 1.41, respectively, and the fog at the initial and 50,000-sheet copying was 0.7 and 0.6, respectively.
[0054]
The image density is determined using a Macbeth photometer and may be 1.35 or higher. The fog was measured by measuring the reflectance with a photovolt. A value of 1.2% or less is a good value. Further, the scattering of the toner in the machine was performed by checking whether or not the scattered toner was present on the transfer charger of the copying machine. When toner scattering is observed on the transfer charger, image smearing occurs.
[0055]
Examples 2-6 and Comparative Examples 1-4
Instead of using the charge control agent 1 used in Example 1, the same evaluation as in Example 1 was performed except that the charge control agent shown in Table 2 was used. The results are shown in Table 3.
[0056]
[Table 2]

[0057]
Example 7
55.5 parts by weight of styrene-n-butyl acrylate copolymer
40 parts by weight of magnetic iron oxide
Charge control agent 1 2 parts by weight
2 parts by weight of polypropylene wax
0.5 parts by weight of paraffin wax
After mixing with a Henschel mixer, the mixture was put into a biaxial heating kneader, and the kneaded and extruded product was cooled at room temperature and coarsely ground with a hammer mill to obtain chips. Next, this was finely pulverized by a turbo mill, and led to a classifier, and a part having an average particle size of 10 μm was taken out as a fine powder for toner. To 100 parts by weight of the fine powder for toner, 0.25 part by weight of silica hydrophobized with silicone oil was added and mixed with a Henschel mixer to obtain a positively chargeable magnetic toner. I investigated. The heat aging test was carried out by placing the toner in a dryer at 50 ° C. 72 time After accelerating the heat deterioration by allowing it to stand, 50,000 continuous images were taken using a commercially available copying machine (Canon NP4145 manufactured by Canon Inc.) under an environmental condition of 23 ° C. and 50 RH. The image densities at the initial and 50,000-sheet copying were 1.44 and 1.39, respectively, and the fog at the initial and 50,000-sheet copying was 0.5 and 0.7, respectively. Further, there was no scattering of toner particles in the machine after copying 50,000 sheets, and the obtained image was not stained.
[0058]
Examples 8-12 and Comparative Examples 5-8
Instead of using the charge control agent 1 used in Example 7, the same evaluation as in Example 7 was performed except that the charge control agent shown in Table 3 was used. The results are shown in Table 3.
[0059]
[Table 3]

[0060]
【The invention's effect】
As described above, by using the compound of the present invention as a charge control agent for an electrostatic charge image developing toner, an electrostatic charge image developing toner in which the charge control agent is uniformly dispersed can be obtained. It is possible to obtain a copy image having a good image density from the beginning and having no fog, and there is no decrease in the image density even when a large number of copies are stacked, and the toner for developing an electrostatic image of the present invention is heated. It is possible to obtain a good toner that does not change with time and does not change in characteristics due to heating stress until it is commercially available or after storage, or when it is transported.

Claims (7)

An electrostatic charge image developing toner comprising at least a binder resin, a colorant, and a charge control agent, wherein the charge control agent is a compound represented by the following general formula (1): .

(In the formula, R represents a C _{5 to} C ₂₅ saturated or unsaturated monovalent aliphatic group.) The toner for developing an electrostatic charge image according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. 3. The electrostatic image developing toner according to claim 1, wherein the compound represented by the general formula (1) has a volume average particle diameter of 0.5 to 40 μm. The toner for developing an electrostatic image according to claim 1, wherein the toner has a positive charging property. The electrostatic image developing toner according to claim 1, wherein the toner is a dry nonmagnetic toner. The electrostatic charge image developing toner according to claim 1, wherein the toner is a dry magnetic toner. C. of structural formula (2) I. An electrostatic image developing toner comprising a compound obtained by reacting Solvent Violet 9 and a fatty acid represented by the general formula (3).

(In the formula, R represents a C _{5 to} C ₂₅ saturated or unsaturated monovalent aliphatic group.)