JP2004347917A - Electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive charge type electrostatic charge image developing toner having superior properties, that is, a positive charge type electrostatic charge image developing toner which ensures a large stable tribocharge amount between the toner and a carrier and between the toner and a toner carrier such as a developing sleeve and can form a stable toner image independently of temperature and humidity. <P>SOLUTION: In the electrostatic charge image developing toner containing at least a binder resin, a colorant and a charge control agent, the charge control agent is a salt prepared by reacting C.I. Basic Blue 7 with C.I. Acid Yellow 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１６】
また、第２の発明は、上記一般式（１）で表される造塩化合物の含有量が、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。
【００１７】
また、第３の発明は、上記一般式（１）で表される造塩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。
【００１８】
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。
【００１９】
また、第５の発明は、トナーが、乾式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。
【００２０】
また、第６の発明は、トナーが、乾式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。
【００２１】
また、第７の発明は、少なくとも結着樹脂、着色剤、荷電制御剤を含有する静電荷像現像用トナーにおいて、荷電制御剤がＣ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７とＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２とを反応させてなる造塩化合物であることを特徴とする静電荷像現像用トナーである。
【００２２】
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、本発明の造塩化合
物は、構造式（１）で表される、Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７とＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２とを反応せしめて得られる一般式（１）で表される造塩化合物である。
【００２３】
【化３】

【００２４】
具体的には以下の手順により得られる。
（４−メチルアニリンのジアゾ化）
まず、水を入れたビーカーを攪拌しながら４−メチルアニリンを加える。更に塩酸を室温で加え溶解し氷を加え、水温を０℃以下に保持しながら、亜硝酸ナトリウムの水溶液を加え４−メチルアニリンをジアゾ化する。
（カップリング液の調整及び反応）
水の入ったビーカーを攪拌しながら水酸化ナトリウムを添加する。更に３−メチル−１−（ｐ−スルホフェニル）−５−ピラゾロンを加えて、室温で攪拌溶解した後、氷を加えて１０℃以下に保持して、上記アニリンをジアゾ化した溶液を添加し、Ｃ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２の溶液を合成する。更にここで塩酸を用いて該溶液をｐＨ７に調整しておく。
（Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７溶液の調整及びＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２との反応）
Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７（Ｖｉｃｔｏｒｉａ Ｐｕｒｅ ＢｌｕｅＦＢＯ）をメタノールに溶解させ、次に７０℃の湯を加え溶解液を作製し、６０℃に保持しながら攪拌し、上記調整したＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２の溶液に時間を要して加えた後、６０〜７０℃で乾燥し、Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７とＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２とからなる結晶の造塩化合物を得る。
【００２５】
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トナーが溶出してしまい、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。ここでは不溶で水溶液に色がつかないことが好ましく耐水性に優れている。
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。ここでは不溶でシリコイーンオイルの溶液に色がつかないことが好ましく耐油性に優れている。
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。Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７、Ｃ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２ともに水溶性を有する物質でありそれ自身としては荷電制御剤として使用することは困難であるが、これらを用いて反応せしめ得られる造塩化合物はこれらの評価方法において耐水性、耐油性ともに優れたものである。
【００２６】
また本発明の造塩化合物は良好な正帯電性を有しており荷電制御剤として優れた品位を有したものである。これは良好な正帯電性を有するＣ．Ｉ．ＢａｓｉｃＢｌｕｅ ７を用いて、Ｃ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２と反応させることにより耐水性、耐油性の大きな改良が実現でき、良好な荷電制御剤が得られたのである。
【００２７】
本発明の造塩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３〜２０μｍであることが良い。４０μｍよりも大きい粒径のものを用いると、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。
【００２８】
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。
【００２９】
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化合物が好ましい。
【００３０】
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。
【００３１】
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。
【００３２】
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。
【００３３】
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。
【００３４】
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 １０^３ から５ｘ １０^４ の領域に少なくとも一つのピークを有し、かつ１０^５ 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。
【００３５】
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。
【００３６】
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。
【００３７】
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。
【００３８】
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。
【００３９】
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３〜１３μｍ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５〜１０μｍ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。
【００４０】
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。
【００４１】
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。
【００４２】
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。
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１ 下記の（１）〜（３）の手順にて荷電制御剤１を合成した。
（１）４−メチルアニリンのジアゾ化
ビーカーに水３００ｇを入れ、攪拌しながら４−メチルアニリン２１．４ｇ（０．２モル）を加え、更に３５％の塩酸５２ｇ（０．５モル）を室温下で加え溶解した後、氷を加え水温を−２℃とし、亜硝酸ナトリウム１５ｇ（０．２モル）を水５２ｇに溶解した溶液を加え４−メチルアニリンをジアゾ化した。
（２）カップリング液の調整及び反応
ビーカーに水９００ｇを加え攪拌しながら、水酸化ナトリウムを２１ｇを加えた後、３−メチル−１−（ｐ−スルホフェニル）−５−ピラゾロンを５１ｇ（０．２モル）加え室温で３０分間攪拌溶解させた。氷を加え水温を７℃とし、（１）の溶液を１０分間かけて加え、Ｃ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２の０．２モル溶液を合成した。このとき該溶液を２５℃でｐＨ７になるように塩酸で調整した。
（３）Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７溶液の調整及びＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２との反応
Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７ １２０ｇをメタノール６００ｇに溶解させ、次に７０℃の湯１２００ｇを加え、溶解液を作製し、得られた溶解液を攪拌しながら（２）の溶液に６０分間かけて加えた後、６０〜７０℃で乾燥し、Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７とＣ．Ｉ．Ａｃｉｄ Ｙｅｌｌｏｗ １２とからなる結晶の造塩化合物を得た。さらに、粉砕機（ジェットミル）にて粉砕し体積平均粒径７．２μｍの荷電制御剤１を得た。
【００４５】
【化４】

【００４６】
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取り出して、トナー用微粉末を得た。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０．２５重量部、およびタングステンカーバイド微粉体０．３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１．３９および１．３８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０．４であった。詳細の結果を下記表１に示す。
【００４７】
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。
【００４８】
【表１】

【００４９】
比較例１
実施例１に用いた荷電制御剤１を用いる代わりに、Ｃ．Ｉ．Ｂａｓｉｃ Ｂｌｕｅ ７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１示す。
【００５０】
比較例２
実施例１に用いた荷電制御剤１を用いる代わりに、ニグロシンベース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１示す。
【００５１】
比較例３
実施例１に用いた荷電制御剤１を用いる代わりに、四級アンモニウム塩化合物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１示す。
【００５２】
実施例２
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０．３重量部を加え、ヘンシェルミキサーで混合して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１．３７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０．４および０．６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。詳細の結果を下記表２に示す。
【００５３】
【表２】

【００５４】
比較例４〜６
実施例２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２と同様の評価を行った。結果を表２に示す。
【００５５】
【発明の効果】
以上述べたように、本発明の造塩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]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image in an electronic 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 of developing an electrostatic latent image formed on an electrostatic image carrier such as an electrophotographic photosensitive member or an electrostatic recording member, a method of developing an electrostatic latent image is roughly classified into a liquid developing method in which fine toner is dispersed in an electrically insulating liquid. There are two methods known: a method using an agent (wet development method) and a method using a toner in which a colorant or a magnetic powder or the like 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 toner and a method using a one-component developer composed only of toner are known.
[0003]
The toner for developing an electrostatic charge image used in these dry developing methods is usually formed by using a styrene-based resin or a polyester-based resin as a binder resin, kneading a colorant such as a dye or a pigment, cooling, and then pulverizing. , Manufactured through a classification process. The particle diameter of the electrostatic image developing toner generally has an average particle diameter of about 1 to 30 μm. In the case of a magnetic toner, a magnetic powder such as magnetite is further used. In addition, as the carrier particles used in the two-component developer, glass beads, iron powder, magnetite, and the like, which are coated with a resin as necessary, are used.
[0004]
The toner for developing an electrostatic image as described above is required to hold a positive or negative charge according to the polarity of the electrostatic latent image to be developed. In order to retain the charge in the electrostatic image developing toner, it is possible to utilize the triboelectrification properties of the toner components such as a binder resin and a colorant, but this alone alone usually has a small charge amount and a stable polarity. Therefore, the image obtained by development is easily fogged and unclear. For this reason, a substance called a charge control agent is generally added to the toner in order to impart desirable charging characteristics to the toner.
[0005]
Typical examples of conventional charge control agents include those that impart a positive charge to a toner, for example, a basic dye such as a triarylmethane dye, a nigrosine dye, a quaternary ammonium salt compound, and an organic tin. Electron-donating substances such as oxides and polymers having an amino group, and those which impart negative charge to the toner include, for example, metal complexes of monoazo dyes, metal compounds of aromatic hydroxycarboxylic acids, and organic dyes containing chromium (eg, copper phthalocyanine green, Metal-containing dyes such as chromium-containing monoazo dyes).
[0006]
In recent years, it has become common to use an organic photoconductor as a photoconductor of an electrophotographic copying machine or a printer, and a positively chargeable toner is used as a developer for a copying machine or a printer using the organic photoconductor. However, the positively chargeable charge control agent used for producing this positively chargeable toner is often hydrophilic, and the charge amount tends to decrease under high humidity conditions, while the charge amount decreases under high humidity conditions. Those which do not have many problems that the charge amount becomes unnecessarily high under low humidity. In addition, the positively chargeable charge control agent often suffers from deterioration due to heat when the toner is left at a high temperature for a long period of time, thereby causing problems such as increase in fog and scattering in the machine. For example, the nigrosine dye has a high chargeability, but has a very strong positive chargeability, so that the charge amount of the toner becomes excessively high, and the image density may decrease as the number of copies increases. It is difficult to obtain one that sufficiently satisfies the conditions required as an agent. Further, the quaternary ammonium salt has a low charge-imparting ability, and under high temperature and high humidity, as the number of copies increases, fog may increase and scattering in the machine may be observed. In addition, degradation due to high temperature storage often occurs.
[0007]
In addition, triarylmethane dyes such as methyl violet, crystal violet, crystal violet base and methyl violet base are also generally used as positively chargeable charge control agents. I. Victoria Pure Blue represented by Basic Blue 7, and a laked pigment thereof (for example, see Patent Documents 1, 2, and 3; Patent Document 1 is used as a colorant); I. A salt-forming compound comprising Basic Blue 7 and an anion (for example, see Patent Documents 4 and 5) is also used as a positively chargeable charge control agent.
These have excellent positive chargeability, but have problems in water resistance or oil resistance, and are often difficult to use practically as toners. If the water resistance is poor, the environmental stability deteriorates, and particularly under high humidity, the charge amount decreases, fog increases, and scattering inside the machine occurs. In addition, these dyes elute from the toner and cause image contamination. On the other hand, if the oil resistance is poor, when the silicone oil or the like is used in the fixing unit, when the toner is melted, these dyes elute and cause color contamination of the fixing unit and the image.
[0008]
[Patent Document 1]
JP-A-62-296167 (page 15, lower right B-21)
[Patent Document 2]
JP-A-61-36758 (Claims)
[Patent Document 3]
JP-A-2-53076 (Claims)
[Patent Document 4]
JP-A-61-6659 (Claims)
[Patent Document 5]
JP-A-2-123374 (Claims)
[0009]
[Problems to be solved by the invention]
As described above, the triarylmethane dye is a relatively excellent positively chargeable charge control agent, but has various problems. Solves these problems, has excellent water resistance and oil resistance, has a moderately high charge amount, is stable, has little dependence on temperature and humidity during development, has no deterioration in toner characteristics due to high temperature and high humidity storage, and has a binder resin. There is a demand for a positively chargeable charge control agent which has good dispersibility with respect to toner, excellent development characteristics and excellent durability, and a positively chargeable toner containing the same.
[0010]
An object of the present invention is to provide a positively chargeable electrostatic image developing toner having excellent characteristics without the above-mentioned problem, that is, a high frictional charge amount between the toner and the carrier, between the toner and a toner carrier such as a developing sleeve, An object of the present invention is to provide a positively chargeable electrostatic image developing toner which is stable and can form a stable toner image without being affected by temperature and humidity.
[0011]
Another object of the present invention is to provide a toner for developing a positively chargeable electrostatic image, which has a stable triboelectric charge amount even when the number of copies is increased, does not generate fog, and does not scatter the toner into the machine.
[0012]
It is another object of the present invention to provide a positively chargeable electrostatic image developing toner capable of forming a clear image free from fog, in which a charge control agent is uniformly dispersed in a toner. .
[0013]
It is a further object of the present invention to provide a positively chargeable toner for developing an electrostatic image, which does not deteriorate the toner characteristics due to thermal stress during storage of the toner.
[0014]
[Means for Solving the Problems]
The present inventors have conducted intensive studies and found that C.I. I. Basic Blue 7 and C.I. I. The present inventors have found that the above object can be achieved by using a salt-forming compound composed of Acid Yellow 12 as a charge control agent, and have accomplished the present invention.
[0015]
That is, the first invention is a toner for developing an electrostatic image containing at least a binder resin, a colorant, and a charge control agent, wherein the charge control agent contains a salt forming compound represented by the following general formula (1). And a toner for developing an electrostatic image.
Embedded image

[0016]
The second invention is characterized in that the content of the salt forming compound represented by the general formula (1) is 0.1 to 10 parts by weight based on 100 parts by weight of the binder resin. The toner for developing an electrostatic image of the first invention.
[0017]
A third aspect of the present invention is the electrostatic charge of the first or second aspect, wherein the salt-forming compound represented by the general formula (1) has a volume average particle diameter of 0.5 to 40 μm. This is an image developing toner.
[0018]
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 charge property.
[0019]
A fifth aspect of the present invention is the electrostatic image developing toner according to any one of the first to fourth aspects, wherein the toner is a dry non-magnetic toner.
[0020]
A sixth invention is the toner for developing an electrostatic image according to any one of the first to fourth inventions, wherein the toner is a dry magnetic toner.
[0021]
A seventh aspect of the present invention is a toner for developing an electrostatic image containing at least a binder resin, a colorant and a charge control agent, wherein the charge control agent is C.I. I. Basic Blue 7 and C.I. I. A toner for developing an electrostatic image, which is a salt forming compound obtained by reacting Acid Yellow 12 with Acid Yellow 12.
[0022]
Hereinafter, the present invention will be described in more detail.
The salt forming compound of the present invention, which is good as a positively chargeable charge control agent for an electrostatic image developing toner, is represented by the following formula (1): I. Basic Blue 7 and C.I. I. It is a salt forming compound represented by the general formula (1) obtained by reacting Acid Yellow 12 with Acid Yellow 12.
[0023]
Embedded image

[0024]
Specifically, it is obtained by the following procedure.
(Diazotization of 4-methylaniline)
First, 4-methylaniline is added while stirring a beaker containing water. Further, hydrochloric acid is added at room temperature to dissolve the mixture, ice is added, and while maintaining the water temperature at 0 ° C. or lower, an aqueous solution of sodium nitrite is added to diazotize 4-methylaniline.
(Coupling liquid preparation and reaction)
Add sodium hydroxide while stirring the beaker with water. Further, 3-methyl-1- (p-sulfophenyl) -5-pyrazolone was added, and the mixture was stirred and dissolved at room temperature. Then, ice was added, the temperature was kept at 10 ° C. or lower, and a solution obtained by diazotizing the aniline was added. , C.I. I. A solution of Acid Yellow 12 is synthesized. Further, the solution is adjusted to pH 7 using hydrochloric acid.
(Preparation of CI Basic Blue 7 Solution and Reaction with CI Acid Yellow 12)
C. I. Basic Blue 7 (Victoria Pure Blue FBO) was dissolved in methanol, and then hot water at 70 ° C. was added to prepare a solution. The solution was stirred at 60 ° C., and stirred. I. Acid Yellow 12 was added to the solution over time, followed by drying at 60-70 ° C. I. Basic Blue 7 and C.I. I. A crystalline salt-forming compound consisting of Acid Yellow 12 is obtained.
[0025]
It is essential that the charge control agent has good water resistance and oil resistance. If the water resistance is poor, the charge control agent is eluted from the toner under high humidity, making it impossible to impart good charge to the toner. Further, contamination of the image and the like due to the elution is caused. On the other hand, if the oil resistance is poor, the toner is eluted in a fixing step using silicone oil or the like, thereby contaminating the fixing member and further contaminating the copied 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. Here, it is preferably insoluble and does not give a color to the aqueous solution, and is excellent in water resistance.
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. Here, it is preferable that the solution of the silicone oil is insoluble and does not have a color, and the oil resistance is excellent.
With respect to the compound of the present invention, water resistance and oil resistance were confirmed by these methods. C. I. Basic Blue 7, C.I. I. Acid Yellow 12 is a water-soluble substance, and it is difficult to use as a charge control agent by itself. However, salt-forming compounds obtained by reacting with these substances are considered to be water-resistant and oil-resistant in these evaluation methods. Both are excellent.
[0026]
Further, the salt forming compound of the present invention has good positive chargeability and has excellent quality as a charge control agent. This is C.I. having good positive chargeability. I. Using BasicBlue 7, C.I. I. By reacting with Acid Yellow 12, significant improvements in water resistance and oil resistance were realized, and a good charge control agent was obtained.
[0027]
The salt forming compound of the present invention can be used more effectively by pulverizing it with a pulverizer and adjusting it to a desired particle size distribution. Examples of the type of the pulverizer include a pneumatic impingement pulverizer such as a jet mill, and a mechanical impact pulverizer such as a turbo mill, KTM, and MVM. A good particle size distribution for the charge control agent of the present invention may be 0.5 to 40 μm, more preferably 3 to 20 μm in volume average particle size. If a particle having a particle size larger than 40 μm is used, it is difficult to disperse the charge control agent in the binder resin, and the charge control agent cannot be dispersed in the toner. Further, the content of the charge control agent per toner particle is biased, which leads to an increase in fog and scattering in the machine. On the other hand, when a particle having a particle diameter 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 becomes large, and excessive charge is applied to the toner. The charge amount increases, and the image density decreases.
[0028]
The amount of the compound of the present invention in the toner for developing an electrostatic image varies depending on the type of the binder resin used, but is usually 0.1 to 10 parts by weight, preferably 0 to 10 parts by weight, per 100 parts by weight of the binder resin. 0.5 to 5 parts by weight, more preferably 0.8 to 3 parts by weight.
[0029]
In the toner for developing an electrostatic image of the present invention, as the charge control agent, other charge control agents may be used together with 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 is conventionally known to be able to impart a positive charge to the toner, and among them, a nigrosine dye and Quaternary ammonium salt compounds are preferred.
[0030]
As the components of the toner for developing an electrostatic image of the present invention, in addition to the charge control agent of the present invention, a binder resin and a coloring agent, which are known materials constituting the toner, are used. When a magnetic toner is obtained, a magnetic powder is further used. However, when a magnetic powder is used, the magnetic powder may be used as a coloring agent. Therefore, in the present invention, the coloring agent includes a magnetic powder. A release agent, a lubricant, a fluidity improver, an abrasive, a conductivity-imparting agent, an image peeling preventive, and the like are further added to the electrostatic image developing toner as necessary.
[0031]
Specific examples of the binder resin used in the toner of the present invention include styrene-based polymers, for example, polystyrene, poly-p-chlorostyrene, a homopolymer of styrene such as polyvinyltoluene and a substituted product thereof, and styrene-p. -Chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic copolymer, styrene-α-chloromethyl methacrylate 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-based copolymer such as styrene-diethylaminoethyl acrylate copolymer, styrene-butyl acrylate-diethylaminoethyl methacrylate copolymer, cross-linked styrene-based copolymer; polyester resin such as aliphatic dicarboxylic acid, aromatic Resin having a monomer selected from the group consisting of genus dicarboxylic acid, aromatic dialcohol and diphenol as a structural unit, crosslinked polyester resin, etc .; other polyvinyl chloride, phenolic resin, modified phenolic resin, maleic resin, rosin modified Maleic 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.
[0032]
Acrylic monomers used in the styrene-acrylic copolymer include, for example, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, acrylic acid (Meth) acrylates such as 2-ethylhexyl, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, and the like, and further usable as monomers such as 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 ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone.
[0033]
Examples of the cross-linking agent used for producing the cross-linked styrene-based polymer include compounds mainly having two or more unsaturated bonds, and 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 and divinyl sulfone; Compounds having two 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.
[0034]
These resins can be used alone or in combination of two or more. Of these resins, styrene polymers and polyester resins are preferred because they exhibit particularly excellent charging characteristics. Also, the molecular weight distribution measured by GPC (gel permeation chromatography) has at least one peak in a region of 1 × 10 ³ to 5 × 10 ⁴ and at least one peak or shoulder in a region of 10 ⁵ or more. Styrene-based copolymers, and furthermore, two or more kinds of resins, for example, a combination of the styrene resin and a styrene-acrylic copolymer or a combination of two or more styrene-acrylic copolymers. A resin composition having a distribution is preferable from the viewpoints of toner pulverizability, fixability, and the like.
[0035]
Further, when a pressure fixing method is used, a binder resin for a pressure toner can be used. Such resins include, for example, polyethylene, polypropylene, polymethylene, polyurethane elastomers, ethylene-ethyl acrylate copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin, and other waxes.
[0036]
As the colorant that can be used in the toner for developing an electrostatic image of the present invention, any colorant that is conventionally known to be used in the production of toner can be used. Examples of these colorants include fatty acids Examples include metal salts, various carbon blacks, phthalocyanine-based, rhodamine-based, quinacridone-based, triarylmethane-based, anthraquinone-based, azo-, and diazo-based dyes and pigments. These can be used alone or in combination of two or more.
[0037]
Further, the magnetic powder used in the toner for developing an electrostatic image of the present invention may be any powder of an alloy, a compound or the like 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, and compounds of divalent metals and iron oxides, metals such as iron, cobalt, and nickel, or aluminum, cobalt, copper, and lead of these metals. Powders of alloys of metals such as, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof. These magnetic powders preferably have an average particle size of about 0.1 to 2 μm, and more preferably about 0.1 to 0.5 μm. The content of the magnetic powder in the toner is about 20 to 200 parts by mass, preferably 40 to 150 parts by mass, based on 100 parts by mass of the thermoplastic resin. The saturation magnetization of the toner is preferably 15 to 35 emu / g (measurement magnetic field: 1 kOe).
[0038]
The toner of the present invention can be used as a two-component developer by mixing with a carrier. The carrier that can be used with the toner of the present invention may be any conventionally known carrier. Examples of carriers that can be used include magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, and the like, or those obtained by treating the surfaces of these with a resin. As the resin for coating the carrier surface, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate copolymer, methacrylate copolymer, fluorine-containing resin, silicone-containing resin, polyamide Resins, ionomer resins, polyphenylene sulfide resins, and the like, and mixtures thereof. Among these, a fluorine-containing resin and a silicone-containing resin are particularly preferable because the formation of spent toner is small.
[0039]
As for the particle diameter of the toner for developing an electrostatic image of the present invention, it is desirable that the weight average particle diameter is 1 to 30 μm, preferably 3 to 13 μm. In particular, 12 to 60% by number of toner particles having a particle diameter of 5 μm or less, 1 to 33% by number of toner particles having a particle diameter of 8 to 12.7 μm, and toner particles having a particle diameter of 16 μm or more Is 2.0% by weight or less, and the weight average particle size of the toner is 5 to 10 μm, from the viewpoint of developing characteristics. The particle size distribution of the toner can be measured using, for example, a Coulter counter.
[0040]
The toner of the present invention may further contain, if necessary, known additives used in the production of toner, such as a release agent, a lubricant, a fluidity improver, an abrasive, a conductivity-imparting agent, and an image peeling inhibitor. Examples of these additives include release agents such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, microcrystalline wax, carnauba wax, sasol wax, and paraffin wax. And these are usually added to the toner in an amount of about 0.5 to 5% by weight. Examples of the lubricant include polyvinylidene fluoride, zinc stearate and the like, and examples of the fluidity improver include silica, aluminum oxide, titanium oxide, silicon-aluminum oxide, and silicon-titanium oxide manufactured by a dry method or a wet method. And those obtained by subjecting them to a hydrophobic treatment, such as silicon nitride, cerium oxide, silicon carbide, strontium titanate, tungsten carbide, calcium carbonate and those obtained by subjecting them to a hydrophobic treatment, as a conductivity-imparting agent; Are carbon black, tin oxide and the like. Further, fine powder of a fluorine-containing polymer such as polyvinylidene fluoride is preferable in terms of fluidity, abrasiveness, charge stability and the like.
[0041]
In the present invention, hydrophobized silica, hydrophobized aluminum oxide, hydrophobized silicon aluminum co-oxide or hydrophobized silicon titanium co-oxide fine powder are used as external additives. Preferably, it is used. Examples of the hydrophobic treatment of the silica fine powder include a treatment with a silane coupling agent such as silicone oil, dichlorodimethylsilane, hexamethyldisilazane, and tetramethyldisilazane. In addition, it is preferable to use positively chargeable silica having a positive tribocharge with respect to the iron powder carrier when measured by a blow-off method. In order to obtain this positively chargeable silica, the silica may be treated with a silicone oil having an organo group having at least one nitrogen atom in a side chain, or a nitrogen-containing silane coupling agent. The amount of the silica fine powder subjected to the hydrophobic treatment is 0.01 to 20%, preferably 0.03 to 5%, based on the weight of the developer.
[0042]
The toner according to the present invention can be manufactured using a conventionally known toner manufacturing method. In general, the above-mentioned toner constituent materials are sufficiently mixed by a mixer such as a ball mill and a Henschel mixer, and then sufficiently kneaded using a hot kneader such as a hot roll kneader or a single-screw or twin-screw extruder. After cooling and solidifying, a method of mechanically coarse pulverization using a pulverizer such as a hammer mill, fine pulverization by a jet mill or the like, and then classification is preferable. After further classification, it is preferable that the external additives are sufficiently mixed and used using a mixer such as a Henschel mixer. However, the method of producing the toner is not limited to this method, and a method of dispersing other toner constituent materials in a binder resin solution, followed by spray drying, a method of producing the toner by a so-called microcapsule method, Other methods, such as a polymerization toner production method in which a predetermined material is mixed with a monomer that forms a resin and emulsion or suspension polymerization is performed to obtain a toner, can be arbitrarily adopted.
The electrostatic image developing toner of the present invention is a preferable 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】
Hereinafter, the present invention will be described more specifically with reference to examples, but embodiments of the present invention are not limited to these examples.
[0044]
Production Example 1 of Charge Control Agent Charge control agent 1 was synthesized according to the following procedures (1) to (3).
(1) Diazotization of 4-methylaniline 300 g of water was placed in a beaker, 21.4 g (0.2 mol) of 4-methylaniline was added with stirring, and 52 g (0.5 mol) of 35% hydrochloric acid was further added. Was added at room temperature to dissolve, and ice was added thereto to adjust the water temperature to −2 ° C., and a solution of 15 g (0.2 mol) of sodium nitrite dissolved in 52 g of water was added to diazotize 4-methylaniline.
(2) Preparation and reaction of coupling solution 900 g of water was added to a beaker, 21 g of sodium hydroxide was added with stirring, and then 3-methyl-1- (p-sulfophenyl) -5-pyrazolone. Was added and stirred and dissolved at room temperature for 30 minutes. Ice was added to adjust the water temperature to 7 ° C., and the solution of (1) was added over 10 minutes. I. A 0.2 molar solution of Acid Yellow 12 was synthesized. At this time, the solution was adjusted to pH 7 at 25 ° C. with hydrochloric acid.
(3) C.I. I. Preparation of Basic Blue 7 solution and C.I. I. Reaction with Acid Yellow 12 I. After dissolving 120 g of Basic Blue 7 in 600 g of methanol, and then adding 1200 g of hot water at 70 ° C. to prepare a solution, the obtained solution is added to the solution of (2) with stirring over 60 minutes. Dried at 60-70 ° C, C.I. I. Basic Blue 7 and C.I. I. Acid Yellow 12 was obtained as a crystalline salt-forming compound. Furthermore, it was pulverized by a pulverizer (jet mill) to obtain a charge control agent 1 having a volume average particle size of 7.2 μm.
[0045]
Embedded image

[0046]
Example 1
Styrene-n-butyl acrylate copolymer 87.5 parts by weight Carbon black 8 parts by weight Charge control agent 1 2 parts by weight Polypropylene wax 2 parts by weight Polyethylene wax 0.5 parts by weight After uniformly mixing the above materials with a Henschel mixer, The mixture was put into a twin-screw kneader, kneaded and extruded, cooled at room temperature, and roughly pulverized with a hammer mill to obtain chips. Next, this was finely pulverized by a turbo mill pulverizer, guided to a classifier, and a portion having an average particle size of 11.5 μm was taken out to obtain a fine powder for toner. Next, 0.25 parts by weight of positively charged hydrophobic silica fine powder and 0.3 parts 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 obtain positively charged hydrophobic silica. A non-magnetic toner was obtained. A developer was prepared by mixing 4 parts of the obtained toner and 100 parts of a silicone resin-coated carrier having an average particle diameter of 100 μm using a ball mill. Next, using the toner and the developer, a commercial copying test was performed in a high-temperature and high-humidity (30 ° C., 85% RH) environment using a commercially available copying machine FP7735 (manufactured by Matsushita Electric Transmission Co., Ltd.). At this time, the toner was heated in a dryer at 50 ° C. for 72 hours in order to promote and confirm the deterioration of the toner by heating. When the obtained toner and developer were used, fog was small, the image density was stable even after 50,000 sheets were actually photographed, and toner scattering and image contamination in the apparatus were not observed. The image densities at the initial and 50,000 copies were 1.39 and 1.38, respectively, and the fog at the initial and 50,000 copies were 0.5 and 0.4, respectively. Detailed results are shown in Table 1 below.
[0047]
The image density is measured using a Macbeth photometer and may be a density of 1.35 or more. The fog was measured by measuring the reflectance with a photobolt. A good value is 1.2% or less. The scattering of the toner inside the apparatus was performed by checking whether or not the scattering toner was present on the transfer charger of the copying machine. When toner is scattered on the transfer charger, an image stain is generated accordingly.
[0048]
[Table 1]

[0049]
Comparative Example 1
Instead of using the charge control agent 1 used in Example 1, C.I. I. The same evaluation as in Example 1 was performed, except that Basic Blue 7 was used. Table 1 shows the results.
[0050]
Comparative Example 2
The same evaluation as in Example 1 was performed except that a nigrosine base was used instead of using the charge control agent 1 used in Example 1. Table 1 shows the results.
[0051]
Comparative Example 3
The same evaluation as in Example 1 was performed except that a quaternary ammonium salt compound was used instead of using the charge control agent 1 used in Example 1. Table 1 shows the results.
[0052]
Example 2
Styrene-n-butyl acrylate copolymer 55.5 parts by weight Magnetic iron oxide 40 parts by weight Charge control agent 1 2 parts by weight Polypropylene wax 2 parts by weight Paraffin wax 0.5 part by weight was mixed with a Henschel mixer, and then biaxially heated. The mixture was put into a kneader, kneaded and extruded, cooled at room temperature, and coarsely pulverized with a hammer mill to obtain chips. Next, this was finely pulverized with a turbo mill and led to a classifier, and a portion having an average particle size of 10 μm was taken out as a fine powder for toner. 0.3 parts by weight of silica hydrophobized with silicone oil was added to 100 parts by weight of the toner fine powder, and mixed with a Henschel mixer to obtain a positively chargeable magnetic toner. The changes were examined. In the test of the change with time in heating, the toner was left in a dryer at 50 ° C. for 72 hours to accelerate the heat deterioration, and then a commercially available copying machine (Copier NP4145 manufactured by Canon Inc.) was used. Under environmental conditions, 50,000 continuous actual shots were taken. The image densities at the initial and 50,000 copies were 1.37 and 1.39, respectively, and the fog at the initial and 50,000 copies were 0.4 and 0.6, respectively, with no particular change. Further, there was no scattering of toner particles in the machine after copying 50,000 sheets, and there was no stain on the obtained image. Detailed results are shown in Table 2 below.
[0053]
[Table 2]

[0054]
Comparative Examples 4 to 6
The same evaluation as in Example 2 was performed, except that the charge control agents shown in Table 2 were used instead of using the charge control agent 1 used in Example 2. Table 2 shows the results.
[0055]
【The invention's effect】
As described above, by using the salt-forming compound of the present invention as a charge control agent for a toner for developing an electrostatic image, a toner for developing an electrostatic image in which the charge control agent is uniformly dispersed can be obtained. The toner has a good image density from the beginning and can obtain a copy image without fogging. In addition, the image density does not decrease even when a large number of copies are superimposed. Can obtain a good toner which has no change over time with heating and does not change its properties due to heating stress during storage or transportation of the toner until it is marketed or purchased.

Claims (7)

An electrostatic charge image developing toner containing at least a binder resin, a colorant, and a charge control agent, characterized in that the toner comprises a salt forming compound represented by the following general formula (1) as a charge control agent. Charge image developing toner.

The electrostatic image developing method according to claim 1, wherein the content of the salt forming compound represented by the general formula (1) is 0.1 to 10 parts by weight based on 100 parts by weight of the binder resin. toner. The electrostatic image developing toner according to claim 1, wherein the salt-forming compound represented by the general formula (1) has a volume average particle diameter of 0.5 to 40 μm. The electrostatic image developing toner according to claim 1, wherein the toner has a positive charge property. 5. The toner according to claim 1, wherein the toner is a dry non-magnetic toner. 5. The toner for developing an electrostatic image according to claim 1, wherein the toner is a dry magnetic toner. In a toner for developing an electrostatic image containing at least a binder resin, a colorant and a charge control agent, the charge control agent is C.I. I. Basic Blue 7 and C.I. I. A toner for developing an electrostatic image, which is a salt-forming compound obtained by reacting with Acid Yellow 12.