JP4292597B2 - toner - Google Patents

Description

【００８０】
(化５)にホモホホバ油アミドの生成過程を示す。
【００８１】
【化５】

【００８２】
また、ホホバ油トリエステルは、ホホバ油をエポキシ化し、水和開環後、有機酸、脂肪酸でアシル化することで得られる。(化６)にその生成過程を示す。
【００８３】
【化６】

【００８４】
添加量としてはトナー１００重量部に対して０．１〜２０重量部が好ましい。０．１重量部より小さいと、定着性、耐オフセット性の効果が得られず、２０重量部より大きいと貯蔵安定性が低下することや、過粉砕等の粉砕性に課題が生じる。融点は４０〜１３０℃の範囲が好ましく、より好ましくは４５〜１２０℃、さらに好ましくは５０〜１１０℃である。４０℃より小さくなると保存安定性が低下し、１３０℃より大きい場合では定着性、耐オフセット性等の定着性機能が低下する。またＧＰＣにおける分子量において、Ｍｎが１００〜５０００、Ｍｗが２００〜１００００、Ｍｗ／Ｍｎが８以下、Ｍｚ／Ｍｎが１０以下のものが好ましい。より好ましくはＭｎが１００〜５０００、Ｍｗが２００〜１００００、Ｍｗ／Ｍｎが７以下、Ｍｚ／Ｍｎが９以下、さらに好ましくはＭｎが１００〜５０００、Ｍｗが２００〜１００００、Ｍｗ／Ｍｎが６以下、Ｍｚ／Ｍｎが８以下である。Ｍｎが１００より小、Ｍｗが２００より小となると保存安定性が悪化する。Ｍｎが５０００より大、Ｍｗが１００００より大、Ｍｗ／Ｍｎが８より大、Ｍｚ／Ｍｎが１０より大となると定着性、耐オフセット性等の定着性機能が低下する。
【００８５】
また他の成分との併用の可能である。例えば、カルウナバワックス、キャンデリラワックス、ラノリン、木ろう、みつろう、オゾケライト、セレシン、ライスワックス等の植物系ワックス、ポリエチレン、ポリプロピレン等のポリオレフィンワックス、脂肪酸アミド、ステアリン酸、パルミチン酸、ラウリン酸、ステアリン酸アルミニウム、ステアリン酸バリウム、ステアリン酸亜鉛、パルミチン酸亜鉛、等の高級脂肪酸或いはその金属物、エステル等の誘導体が一種類又は二種類以上組み合わせての使用も可能である。
【００８６】
好適に使用される結着樹脂は、各種ビニル系モノマーによる単独重合体または共重合体がある。例えば、スチレン、Ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、ｐ―エチルスチレン、２，４−ジメチルアスチレン、ｐ−ｎブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ヘキシルスチレン、P−クロルスチレンなどのスチレンのおよびその誘導体があげられ、とくにスチレンが好ましい。
【００８７】
またアクリル単量体としては、前記一般式（化１）の式中Ｒ１は、水素原子または低級アルキル基、Ｒ２は水素原子、炭素数１２までの炭化水素基、ヒドロキシルアルキル基、ビニルエステル基またはアミノアクリル基である。そのアクリル単量体としては、アクリル酸、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−２−エチルヘキシル、アクリル酸シクロヘキシル、アクリル酸フェニル、メタクリル酸メチル、メタクリル酸ヘキシル、メタクリル酸−２−エチルヘキシル、β−ヒドロキシアクリル酸エチル、γ−ヒドロキシアクリル酸プロピルα−ヒドロキシアクリル酸ブチル、β−ヒドロキシメタクリル酸エチル、γ−アミノアクリル酸プロピル、γ−Ｎ，Ｎ−ジエチルアミノアクリル酸プロピル、エチレングリコールジメタクリル酸エステル、テトラエチレングリコールジメタクリル酸エステル等を挙げることができる。好適なスチレンーアクリル系共重合体としては、スチレン／ブチルアクリレート共重合体であり、特にスチレンを７５〜８５重量％、ブチルアクリレートを１５〜２５重量％含有するものが好適に使用される。
【００８８】
さらに好適に使用される結着樹脂としては、スチレン系、（メタ）アクリル酸系単量体とともに前記化学式（化２）に示す長鎖アルキル基を有する（メタ）アクリル酸系の単量体を共重合させたものがある。これによりホホバ油誘導体の分散性が著しく向上し、非画像部へのカブリの発生、ベタ黒画像部後端部での画像欠け、および、感光体へのフィルミングの発生が防止される。また、定着性、耐オフセット性が良化するとともに、帯電の安定性、高温低湿下の帯電上昇や、二成分現像方式の場合での高湿下でのキャリアとトナーとの混合比率のを一定化するトナー濃度制御不良等の環境課題が抑制される効果がある。結着樹脂１００重量部に対して、０．０１〜８重量部添加される。少ないと効果が得られず、多すぎると樹脂の耐久性が低下する。
【００８９】
さらに、結着樹脂としては、スチレン系、（メタ）アクリル酸系単量体とともに前記化学式（化３）に示すアミノ基を有する（メタ）アクリル酸系の単量体を共重合させたものが好適に使用される。例えば、ジメチルアミノエチル（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート、ジブチルアミノエチル（メタ）アクリレート等のアミノ基を有するビニル系単量体である。これによりホホバ油誘導体を含有したトナーの高温低湿下での過帯電を抑制し、帯電の安定化を図り、画質の安定性が得られる。正帯電性トナーのみならず、負帯電性トナーにも有効である。結着樹脂１００重量部に対して、０．０１〜５重量部添加される。少ないと効果が得られず、多すぎると耐湿性が低下する。
【００９０】
重合体の製造方法としては、バルク重合、塊状重合、溶液重合、懸濁重合、乳化重合などの公知の重合法を使用することができる。重合率３０〜９０重量％までバルク重合を行いついで溶剤と重合開始剤を添加して、溶液重合により反応を継続する方法等も好ましい。
【００９１】
なお、トナーを広範囲の現像プロセス速度（例えば１４０ｍｍ／ｓｅｃ〜４８０ｍｍ／ｓｅｃ）に対応させるためには、前記混練時の添加剤の分散性を向上させることによるトナーの定着性および帯電性の向上だけでなく、結着樹脂の熱溶融による紙への浸透力を更に高めること、および耐オフセット性を向上させるために適度な粘弾性を有するものにすることが必要である。紙への浸透力を高め、耐オフセット性を向上させるためには、結着樹脂の低分子量重合体成分と高分子量重合体成分のそれぞれにおける組成とガラス転移点と分子量を特定するのが好ましい。
【００９２】
結着樹脂全体として重量平均分子量Ｍｗが１０万〜６０万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが５０〜１００、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが３５０〜１２００、高化式フローテスタによる１／２流出温度（以下軟化点）が１００〜１４５℃であることが好ましい。
【００９３】
さらには重量平均分子量Ｍｗが１２万〜４５万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが６０〜９５、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが５００〜１１００、軟化点が１０５〜１３５℃であることがより好ましい。さらには重量平均分子量Ｍｗが１５万〜４５万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが７０〜９５、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが６００〜１１００、軟化点が１１０〜１３５℃であることがより好ましい。定着性および製造段階での粉砕時における粉砕性を更に向上させるためには、結着樹脂はスチレン系成分を５０〜９５重量％含むものが好ましい。また結着樹脂のフローテスターによる流出開始温度は、８０〜１２０℃の範囲、好ましくは８５〜１１０℃の範囲、より好ましくは８５〜１００℃の範囲にあるのがよい。
【００９４】
なお、Ｍｗが１０万より小、Ｍｗ／Ｍｎが５０より小、比Ｍｚ／Ｍｎが３５０より小、軟化点が１００℃より小、流出開始温度が８０℃より小の場合、混練時のせん断力が係りにくく、ホホバ油誘導体の分散性が低下するとともに、低速時での耐オフセット性が悪化する。Ｍｗが６０万より大、Ｍｗ／Ｍｎが１００より大、比Ｍｚ／Ｍｎが１２００より大、軟化点が１４５℃より大、流出開始温度が１２０℃より大の場合、高速時での定着性が悪化し、粉砕性が悪化する。
【００９５】
Ｚ平均分子量は最もよく高分子量側のテーリング部における分子量の大きさと量を表し、ホホバ油誘導体を添加したトナー特性において大きな影響を与える。Ｍｚが大きいほど樹脂強度が増大し、熱溶融混錬時の粘度が増大して、分散性が著しく向上する。カブリ、トナー飛散を抑えることが出来るとともに、高温低湿下、高湿下の環境変動を抑制できる効果が得られる。Ｍｚ／Ｍｎが大きくすることは、超高分子量領域まで幅広く広がっているものであり、混練時での溶融性がよく溶融粘度を上げている。
【００９６】
分子量は、数種の単分散ポリスチレンを標準サンプルとするゲル・パーミエーション・クロマトグラフィーによって測定された値である。すなわち、温度２５℃においてテトラヒドロフランを溶媒として毎分１ｍｌの流速で流し、これに濃度０．５ｇ／ｄｌのテトラヒドロフラン試料溶液を、試料重量で１０mg注入して測定した値である。測定条件は、対象試料の分子量分布が、数種の単分散ポリスチレン標準試料により得られる検量線における分子量の対数とカウント数が直線となる範囲内に包含される条件である。
【００９７】
また、結着樹脂の軟化点は、島津製作所のフローテスタ（ＣＦＴ５００）により、１ｃｍ³ の試料を昇温速度６℃／分で加熱しながらプランジャーにより２０ｋｇ／ｃｍ² の荷重を与え、直径１ｍｍのノズルから押し出して、このプランジャーの降下量と昇温温度特性との関係から、その特性線の高さをｈとしたとき、ｈ／２に対する温度を軟化点（Ｔｍ）、押し出した時の流出開始したときの温度を流出開始温度（Ｔｉ）とした。
【００９８】
ＤＳＣ法による吸熱ピークの融点は、島津製作所の示差熱量分析計ＤＳＣ−５０を使用した。５℃／ｍｉｎで２００℃まで昇温し、５分間保温１０℃まで急冷後、１５分間放置後５℃／ｍｉｎで昇温させ、吸熱（融解）ピークから求めた。セルに投入するサンプル量は１０ｍｇ＋−２ｍｇとした。
【００９９】
また、本形態のトナーでは、結着樹脂中に予めホホバ油誘導体を内添加しておいてもよい。通常予備混合の工程で結着樹脂、着色剤、電荷制御剤等と同時に前記ホホバ油誘導体が混合されるが、均一に混合させるためには、ある程度の攪拌力が必要であり、必然的に混合機槽内の温度が上昇する。そのため低融点のホホバ油誘導体が凝集を起こし、分散不良を生じる。そこで結着樹脂中に分散させておくことでこの問題が解決できる。つまり結着樹脂を以下のような溶剤に溶解して結着樹脂溶液を作成し前記ホホバ油誘導体と混合した後、その結着樹脂溶液を１２０〜２５０℃で常圧脱溶剤あるいは減圧脱溶剤する工程である。結着樹脂やホホバ油誘導体の熱劣化の防止、脱溶剤の効率の観点から１５０〜２２０℃で行うのが好ましい。結着樹脂溶液中に前記ホホバ油誘導体を添加して脱溶剤することによって、結着樹脂と前記ホホバ油誘導体との相分離が抑制され相溶性が向上し、予備混合工程で発生する前記ホホバ油誘導体の分散性が向上するとともに着色剤や他の内添剤の分散性も向上する。さらに前記ホホバ油誘導体の２２０℃における加熱減量は８重量％以下であることが好ましい。加熱減量が８重量％より大きくなると結着樹脂溶液の脱溶剤工程において脱溶剤が十分に行われず、結着樹脂中に残留する。このため結着樹脂のガラス転移点を大きく低下させトナーの貯蔵安定性を損なう。結着樹脂中への添加量は全量行ってもよいし、一部は混合時に添加混合しても構わない。結着樹脂１００重量部に対して０．１〜１０重量部が好ましい。０．１より小であると分散性向上の効果が得られにくい。１０より大きいと、脱溶剤の効率が低下し生産性が悪化する。
【０１００】
溶剤は、ベンゼン、トリオール、キシロール、シクロヘキサン、ソルベントナフサ等の炭化水素系溶剤、メタノール、エタノール、ｉｓｏ−プロピルアルコール、ｎ−ブチルアルコ―ル、ｓｅｃ−ブチルアルコール、ｉｓｏ−ブチルアルコール、アミルアルコール、シクロヘキサノール等のアルコール系溶剤、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン等のケトン系溶剤、酢酸エチル，ｎ−酢酸ブチル、セロソルブアセテート等のエステル系溶剤、メチルセロソルブ、エチルセロソルブ、ブチルセルソルブ、メチルカルビトール等のエーテル系溶剤等が挙げられる。
【０１０１】
また、結着樹脂は多価カルボン酸又はその低級アルキルエステルと多価アルコールとの重縮合によって得られるポリエステル樹脂が好適に使用される。多価カルボン酸又は低級アルキルエステルとしては、マロン酸、コハク酸、グルタル酸、アジピン酸、ヘキサヒドロ無水フタル酸などの脂肪族二塩基酸、マレイン酸、無水マレイン酸、フマル酸、イタコン酸、シトラコン酸などの脂肪族不飽和二塩基酸、及び無水フタル酸、フタル酸、テレフタル酸、イソフタル酸などの芳香族二塩基酸、及びこれらのメチルエステル、エチルエステル等を例示することが出来る。この中でフタル酸、テレフタル酸、イソフタル酸等の芳香族二塩基酸及びそれらの低級アルキルエステルが好ましい。
【０１０２】
多価アルコールとしては、エチレングリコール、１，２−プロピレングリコール、１，３−プロピレングリコール、１，３−ブチレングリコール、１，４−ブチレングリコール、１，６−ヘキサンジオール、ネオペンチルグリコール、ジエチレングリコール、ジプロピレングリコール、ビスフェノールＡエチレンオキサイド付加物、ビスフェノールＡプロピレンオキサイド付加物、などのジオール、グレセリン、トリメチロールプロパン、トリメチロールエタンなどのトリオール、及びそれらの混合物を例示することが出来る。この中でネオペンチルグリコール、トチメチロールプロパン、ビスフェノールＡエチレンオキサイド付加物、ビスフェノールＡプロピレンオキサイド付加物が好ましい。
【０１０３】
重合は公知の重縮合、溶液重縮合等を用いることが出来る。これによって耐塩ビマット性やカラートナーの色材の色を損なうことなしに、良好なトナーを得ることができる。
【０１０４】
多価カルボン酸と多価アルコールの使用割合は通常、カルボキシル基数に対する水酸基数の割合（ＯＨ／ＣＯＯＨ）で０．８〜１．４が一般的である。
【０１０５】
またポリエステル樹脂の酸価は１〜１００が好ましい。１より小であるとホホバ油誘導体の分散性が低下する。１００より大となると耐湿性が低下する。
【０１０６】
このポリエステル樹脂は、重量平均分子量Ｍｗが１万〜３０万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが３〜５０、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１０〜８００、高化式フローテスタによる１／２流出温度（以下軟化点）が８０〜１５０℃、流出開始温度は８０〜１２０℃の範囲であることが好ましい。
【０１０７】
４色重なる像が形成され定着されるカラープロセス用トナーでは、透光性、光沢性の点から、重量平均分子量Ｍｗが１万〜１８万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが３〜２０、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１０〜３００、軟化点が８５〜１２０℃、流出開始温度は８０〜１１０℃の範囲であることが好ましい。より好ましくは、重量平均分子量Ｍｗが１万〜１５万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが３〜１６、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１０〜２６０、軟化点が９０〜１１５℃、流出開始温度は８５〜１１０℃の範囲であることが好ましい。さらに好ましくは、重量平均分子量Ｍｗが１万〜１０万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが５〜１２、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１４〜２２０、軟化点が９５〜１１５℃、流出開始温度は８５〜１０５℃の範囲であることが好ましい。
【０１０８】
１色の現像である白黒プロセス用黒トナーでは、透光性、平滑性はあまり考慮する必要がないが、例えば、広範囲の現像プロセス速度（例えば１４０ｍｍ／ｓｅｃ〜４８０ｍｍ／ｓｅｃ）に対応させる必要がある場合などは、前記混練時の添加剤の分散性を向上させることによるトナーの定着性および帯電性の向上だけでなく、結着樹脂の熱溶融による紙への浸透力を更に高めること、および耐オフセット性を向上させるために適度な粘弾性を有するものにすることが必要である。そのため、重量平均分子量Ｍｗが５万〜３０万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが５〜５０、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが５０〜８００、軟化点が９０〜１５０℃、流出開始温度は８０〜１２０℃の範囲であることが好ましい。より好ましくは、重量平均分子量Ｍｗが８万〜２５万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが７〜４５、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１００〜７００、軟化点が９５〜１４６℃、流出開始温度は８５〜１１５℃の範囲であることが好ましい。さらに好ましくは、重量平均分子量Ｍｗが１０万〜２２万、重量平均分子量Ｍｗと数平均分子量Ｍｎの比Ｍｗ／Ｍｎが９〜４５、Ｚ平均分子量Ｍｚと数平均分子量Ｍｎの比Ｍｚ／Ｍｎが１５０〜６００、軟化点が１００〜１４２℃、流出開始温度は８５〜１１０℃の範囲であることが好ましい。
【０１０９】
また、窒素吸着によるＢＥＴ比表面積は３０〜３５０ｍ²／ｇの疎水性シリカをトナー母体に外添処理する。用いられるシリカはケイ素ハロゲン化合物の蒸気相酸化により生成されたいわゆる乾式法又はヒュームドシリカと称されるシリカである。その表面に存在するシラノール基をシランカップリング剤やシリコーンオイルにより処理、被覆し、耐湿性を向上させる。
【０１１０】
使用されるシリカはジメチルシリコーンオイル、メチルフェニルシリコーンオイル、アルキル変性シリコーンオイル、フッ素変性シリコーンオイル、アミノ変性シリコーンオイル、エポキシ変性シリコーンオイルのうちの少なくとも１種類以上で処理されるシリカが好適に使用される。例えば東レダウコーニングシリコーン社のＳＨ２００、ＳＨ５１０、ＳＦ２３０、ＳＨ２０３、ＢＹ１６―８２３、ＢＹ１６―８５５Ｂ等が挙げられる。
【０１１１】
また両末端にシラノールを持たせたジメチルシリコーンオイルでは、より反応性が向上し、未反応のポリジメチルシロキサンの残留分が低減し、感光体へのフィルミングが減少する。
【０１１２】
これらのシリコーンオイルにより処理されたシリカはトナー母体に添加されているホホバ油誘導体の油脂と好適な接触付着性を有し、トナー表面に均一付着混合され、かつ離脱が少なく、廃トナーリサイクルを行っても安定した流動性が得られる。
【０１１３】
処理は微粉末とシリコーンオイルとをヘンシェルミキサ等の混合機により混合する方法や、シリカへシリコーンオイルを噴霧する方法、溶剤にシリコーンオイルを溶解或いは分散させた後、シリカ微粉末と混合した後、溶剤を除去して作成する方法等がある。
【０１１４】
またシランカップリング処理した後にシリコーンオイル処理することも好ましい。シランカップリング剤としては、ジメチルジクロロシラン、トリメチルクロルシラン、アリルジメチルクロルシラン、ヘキサメチルジシラザン、アリルフェニルジクロルシラン、ベンジルメチルクロルシラン、ビニルトリエトキシシラン、γ−メタクリルオキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、ジビニルクロルシラン、ジメチルビニルクロルシラン等がある。シランカップリング剤処理は、微粉体を攪拌等によりクラウド状としたものに気化したシランカップリング剤を反応させる乾式処理又は、微粉体を溶媒中に分散させたシランカップリング剤を滴下反応させる湿式法等により処理される。
【０１１５】
より好ましい比表面積は５０〜３００ｍ²／ｇ、さらに好ましくは８０〜２５０ｍ²／ｇの範囲にあるのが好ましい。疎水性シリカは一般にトナー母体粒子１００重量部に当たり０．１〜５重量部、好ましくは０．２〜３重量部配合される。比表面積が３０ｍ²／ｇより小となるとトナーの流動性が向上せず、保存安定性が低下する。比表面積が３５０ｍ²／ｇより大となると、シリカの凝集が悪化し、ホホバ油誘導体の定着性の機能を抑制してしまう。
【０１１６】
また本形態のトナーでは、熱風により表面改質処理を施す構成である。これによりホホバ油誘導体が添加されているトナーの流動性、現像性が安定化して耐久性、リサイクル性が向上する。特にホホバ油誘導体が添加されているトナーにおいては、熱風による熱によりトナー表面に露出して定着性、耐オフセット性等の定着特性が向上する。
【０１１７】
またトナー母体に疎水性シリカ、金属酸化物微粉末、金属酸塩微粉末の１種又は１種以上を外添混合添加した後に、熱風により表面改質処理を施す構成でも良好な特性を示す。さらにその表面改質処理後に疎水性シリカ、金属酸化物微粉末、金属酸塩微粉末の１種又は１種以上を外添混合処理してもより良好な特性を示す。
【０１１８】
表面改質処理によりトナー母体が球形化されるのみならず、これらの外添剤を固定化することで、トナー母体からの離脱を防ぐことが出来、廃トナーリサイクル性が向上する。
【０１１９】
さらに、熱によりトナーに添加しているホホバ油誘導体の一部がトナー母体表面に露出することで定着特性が向上するが、高温低湿下での過帯電が若干起こりやすく、また廃トナーをリサイクルする際にクリーニングブレードへの付着が若干起こりやすくなる。また、現像剤の磁気変動(透磁率の変化)を検知してキャリアとトナーの濃度比率を一定にする二成分現像方式では、例えば透磁率センサーを使用する場合であるが、高湿下にて長時間放置した後、トナー濃度コントロールが動作不良となり、トナーが過剰に補給されるオーバートナー現象となり、カブリ、飛散の増大が生じ易くなる傾向にある。
【０１２０】
しかし、流動性を安定化させる構成、さらには疎水性シリカ等をトナー母体表面に固定化付着させることで、高湿下での放置時のパッキング現象を緩和し、高温低湿下、高湿下での動作不良を抑制し、帯電を安定化することが可能となる。
【０１２１】
図面を用いて説明する。図１は熱風による表面改質処理装置の概略図である。粉砕分級によって所定の粒度分布にされ、トナー粒子１０１は定量供給機１０２から投入され、圧縮空気１０３により粒子の分散手段である分散ノズル１０４に送られ、ここで約４５度の方向に噴射される。分散ノズル１０４は左右対称の位置に２個配置される。複数個のノズルから噴射させることによりトナーがより均一に処理されやすくなるためである。分散ノズル１０４から噴射されるトナー１０１に熱風を放射するため、熱風発生装置１０５から熱風１０６が放射される。熱風発生装置１０５としてヒータを使用している。これは熱風を発生できるものであればよくプロパンガス等により加熱されたもの等装置は限定しない。熱風１０６中をトナー１０１が分散しながら通過し、こで表面改質処理される。表面改質されたトナーはフード１０７内に取り込まれ、サイクロン１１０に送られ回収ボックス１１１に補集回収される。１１２はバグフィルタ、１１４はブロア、１１３は風量計、１１５は温度計である。
【０１２２】
また、フード１０７内に取り込まれた表面改質された被処理粒子に、冷却空気発生装置１０８から発生される冷却空気１０９により冷却処理を施すことも可能である。この急速冷却により処理の状態を安定化させる。風量は処理量により適当に決められる。粒子が熱風で処理される位置から冷却空気が当てられる地点までの距離は、処理量により決められるが１０〜１００ｃｍ、好ましくは２０〜８０ｃｍである。冷却処理は冷却器により１０℃以下に冷却された空気による方法が好ましいが、限定はしない。水冷による方法、ドライアイス等、配管の周囲に冷却された固体物を配置する方法等がある。
【０１２３】
上記方式で行うと連続式のため、生産効率が向上する。
また分散状態で表面改質が行われるので、粒子同士が融着したり、粗粒を生じることがない。また非常に簡単な構成でコンパクトである。機壁温度の上昇がなく製品回収率が高く、開放型のため粉塵爆発の可能性がほとんどない。瞬時に熱風により処理するため粒子相互の凝集もなく、キャリア粒子全体が均一に処理される。この時の処理の熱風温度は６０℃〜６００℃が好ましい。好ましくは１００℃〜５００℃、より好ましくは１５０℃〜３５０℃である。６０℃より小のとき表面改質処理の効果が得られない。６００℃より大きい場合ではトナー母体粒子同志の凝集が起こり易くなり、不適である。熱風風量は風圧３〜５ｋｇ／ｃｍ²Ｇで０．３５〜１．０Ｎｍ³／ｍｉｎ、原料供給分散風量は風圧１〜３ｋｇ／ｃｍ²Ｇで０．０５〜０．５Ｎｍ³／ｍｉｎが好適な範囲である。熱風風量と原料供給分散風量の比は１０：１〜４：１の範囲が好ましい。熱風風量が大き過ぎると原料がはじかれて均一な処理が出来ない。原料供給分散風量が大き過ぎると原料が熱風中を横切り均一な処理が出来ない。
【０１２４】
また、この熱処理はトナー母体に疎水性シリカを外添付着させた後に熱処理を施して、トナー母体に固定化させても構わない。特に廃トナーをリサイクルする際に外添剤の離脱が抑えられ、より耐久性が向上する。これにより定着性のより向上と、長期使用時のトナーの過帯電を防止でき、非画像部の低カブリと高画像濃度を長期に維持する事が可能となる。
【０１２５】
また、平均粒径０．０２〜４μｍ、窒素吸着によるＢＥＴ比表面積が０．１〜１００ｍ²／ｇであるチタン酸塩系微粉末又はジルコニア酸塩系微粉末のうちの少なくとも１種類以上からなる金属酸塩微粉末をトナーに含有することにより、ホホバ油誘導体を添加したトナーにおいて良好な特性を示す。特に廃トナーリサイクル時の帯電の安定化、フィルミングの防止、低湿下での連続使用時の帯電の維持性に効果がある。
【０１２６】
材料としては、ＳｒＴｉＯ3、ＢａＴｉＯ3、ＭｇＴｉＯ3、ＡｌＴｉＯ3、ＣａＴｉＯ3、ＰｂＴｉＯ3、ＦｅＴｉＯ3、ＳｒＺｒＯ3、ＢａＺｒＯ3、ＭｇＺｒＯ3、ＡｌＺｒＯ3、ＣａＺｒＯ3、ＰｂＺｒＯ3、ＳｒＳｉＯ3、ＢａＳｉＯ3、ＭｎＳｉＯ3、ＣａＳｉＯ3、ＭｇＳｉＯ3が挙げられる。
【０１２７】
また、これらの金属酸塩微粉末が水熱法又はシュウ酸塩熱分解法により作成されることにより、より効果が高まる。これらは生成された材料が粒度分布の揃った、形状が不定形よりも球状に近い形となっているためである。平均粒径が０．０２μｍより小、窒素吸着によるＢＥＴ比表面積が１００ｍ²／ｇより大では粒子の凝集が強く分散性が低下する。平均粒径が４μｍより大、窒素吸着によるＢＥＴ比表面積が０．１ｍ²／ｇより小では粒子による感光体への損傷が増大する。
【０１２８】
この水熱条件下での微粉末の合成法としては、水熱酸化法、水熱沈澱法、水熱合成法、水熱分散法、水熱結晶化法、水熱加水分解法、水熱アトリーダ混合法、水熱メカノケミカル法等がある。好ましくは、水熱酸化法、水熱沈澱法、水熱合成法、水熱分散法、水熱加水分解法である。
【０１２９】
この方法によって合成された微粉末は、凝集の少ない、粒度分布の狭い、流動性の良い球状の微粉末が得られる。そのためトナーに外添混合処理したとき分散性が良く、トナーに均一に付着する。そして形状が球状のため感光体に無用な傷を与えることがない。
【０１３０】
さらに、平均粒径０．０２〜２μｍ、窒素吸着によるＢＥＴ比表面積が０．１〜１００ｍ²／ｇ、電気抵抗率が１０⁹Ωｃｍ以下である酸化チタン微粉末、酸化アルミニウム微粉末、酸化ストロンチウム微粉末、酸化錫微粉末、酸化ジルコニア微粉末、酸化マグネシウム微粉末、酸化インジウム微粉末のうちの少なくとも１種類以上からなる金属酸化物微粉末を含有することによりホホバ油誘導体を添加したトナーに対して好適に使用される。
【０１３１】
より好ましくは、平均粒径０．０２〜０．８μｍ、窒素吸着によるＢＥＴ比表面積が１．０〜８５ｍ²／ｇ、さらに好ましくは、平均粒径０．０２〜０．１μｍ、窒素吸着によるＢＥＴ比表面積が８〜８５ｍ2／ｇ、よりさらに好ましくは、平均粒径０．０２〜０．０６μｍ、窒素吸着によるＢＥＴ比表面積が１０〜８５ｍ²／ｇである。
【０１３２】
ホホバ油誘導体を含有したトナーの高温低湿下での帯電性、さらには転写性、そして廃トナーリサイクル性の安定化に効果が得られる。また二成分現像で使用した場合のトナー濃度制御を安定化、特に高温低湿下において効果が得られる。
【０１３３】
平均粒径が０．０２μｍより小、窒素吸着によるＢＥＴ比表面積が１００ｍ²／ｇより大となると凝集性が強く、外添処理時の均一分散ができない。電気抵抗率が１０⁹Ωｃｍより大となると、上記効果が低下する。平均粒径が２μｍより大、窒素吸着によるＢＥＴ比表面積が０．１ｍ²／ｇより小となると、トナー母体からの離脱がひどくなり耐久性に影響を与えるし、感光体への損傷が大きくなる。
【０１３４】
またさらに、窒素吸着によるＢＥＴ比表面積１〜２００ｍ²／ｇの酸化スズ−アンチモンの混合物で表面被覆処理された酸化チタン及び／または酸化シリカ微粉末からなる金属酸化物微粉末を含有することによりホホバ油誘導体を添加したトナーに対して好適に使用される。２００ｍ²／ｇより大では混合処理が均一に行えず、１ｍ²／ｇより小ではトナーからの脱離が増大しトナーの耐久性を低下される。
【０１３５】
またさらに、平均粒径が０．０２〜２．０μｍでかつ２５％残留径Ｄ２５と７５％残留径Ｄ７５の比Ｄ２５／Ｄ７５が１．３〜１．７の範囲内であり、窒素吸着によるＢＥＴ比表面積は０．５〜８０ｍ²／ｇであり、電気抵抗が１０²〜１０¹¹Ωｃｍであり、バルク密度が０．３〜０．９ｇ／ｃｃかつ圧縮率は３０〜８０％であり、アマニ油吸油量が１０〜３０（ｍｌ／１００ｇ）であり、残留磁化が５〜２０ｅｍｕ／ｇ、飽和磁化が４０〜８０ｅｍｕ／ｇである磁性体微粉末からなる金属酸化物微粉末を含有することによりホホバ油誘導体を添加したトナーに対して好適に使用される。
【０１３６】
磁性体微粉末は鉄、コバルト、ニッケル、マンガン、マグネタイトなどの強磁性体を示す金属、合金またはこれらの金属を含む化合物が好適に用いられる。磁性体微粉末の形状は球形状又は八面体形状のものが好ましい。磁性体微粉末の平均粒径は０．０２〜２．０μｍ、かつＤ２５／Ｄ７５が １．３〜１．７であることが好ましい。好ましくは平均粒径が０．０５〜１．０μｍ、比Ｄ２５／Ｄ７５が １．３〜１．６、更に好ましくは平均粒径が０．０５〜０．５μｍ、比Ｄ２５／Ｄ７５が １．３〜１．５である。
【０１３７】
磁性体微粉末の粒径が０．０２μｍより小、または比Ｄ２５／Ｄ７５が１．３より小では、小粒径粒子の割合が高くなり凝集性が強く、混合時の分散性が向上せず、添加の効果が発揮できない。磁性体微粉末の粒径が２．０μｍより大、または比Ｄ２５／Ｄ７５が１．７より大では、大粒径粒子の割合が高くなくとともに、粒度分布の幅が広くなり、大粒径粒子の割合、小粒径粒子の割合がともに多くなり、画質不良が発生したり、トナー母体表面への均一付着が困難になり、感光体への傷等が増大する。走査型電子顕微鏡にて写真を撮影し、無作為に100粒子を選択し、その粒子径を測定した。
【０１３８】
磁性体微粉末の窒素吸着によるＢＥＴ比表面積は０．５〜８０ｍ²／ｇであることが好ましい。より好ましくは２〜６０ｍ²／ｇ、より好ましくは１０〜６０ｍ²／ｇ、よりさらに好ましくは、１８〜６０ｍ²／ｇ範囲にあるものがより好ましい。０．５ｍ²／ｇより小さくなるとトナー母体との接触率が減少するため、磁性体粒子の添加の効果が得にくい。８０ｍ²／ｇより大きくなると粒子の凝集が強くなり混合時の分散が不均一となり、現像性、トナー濃度制御安定性に対する効果が得にくい。ＢＥＴ比表面積は島津製作所製ＦｌｏｗＳｏｒｂII２３００を使用して測定した。
【０１３９】
磁性体微粉末の抵抗は１０²〜１０¹¹Ωｃｍのものが好ましい。好ましくは１０⁵〜１０¹⁰Ωｃｍ、より好ましくは１０⁶〜１０⁹Ωｃｍのものが好ましい。低抵抗の粉体では高湿下において帯電量の低下が大きく、カブリトナー飛散が増大する。高抵抗になると高温低湿下での過帯電を抑制する効果が弱くなる。
【０１４０】
体積電気抵抗の測定は、底面が内径２０ｍｍの電極からなり、側壁が絶縁材料からなる円筒状容器に１ｍｌの磁性粒子材料を入れた後、被検材料の上に直径２０mm弱で重さ100gの電極板を乗せ、1時間放置した後、両電極間に１００Ｖの直流電圧を印加して、印加後1分後の電流値を測定して算出した。
【０１４１】
磁性体微粉末のバルク密度が０．３〜０．９ｇ／ｃｃで、かつ圧縮率は３０〜８０％が好ましい。より好ましくはバルク密度が０．４〜０．９ｇ／ｃｃで、かつ圧縮率は４０〜７０％が好ましい。更に好ましくはバルク密度が０．５〜０．９ｇ／ｃｃで、かつ圧縮率は４５〜６５％が好ましい。バルク密度が０．９ｇ／ｃｃより大、圧縮率が３０％より小になると、高湿下に放置すると現像剤自体の密度が詰まりやすくなり、逆に高湿下でのトナー濃度制御が不安定になり、オーバートナーに走る。バルク密度が０．３ｇ／ｃｃより小、圧縮率が８０％より大になると、粒子の凝集が大きくなり、均一な混合を妨げる結果となり、高温低湿下での過帯電の抑制効果がなくなる。バルク密度、圧縮率はホソカワミクロン社製パウダーテスタにて測定した。圧縮率はゆるみ比重であるバルク密度とタップ密度との差をタップ密度で割ったものに１００をかけたものである。磁性体微粉末は解砕処理されることも好ましい。高速回転子を具備している機械式粉砕機や、加圧ローラを具備している加圧分散機によって行われるのが好ましい。磁性体微粉末のアマニ油吸油量が１０〜３０（ｍｌ／１００ｇ）になるものが好ましい。上記した圧縮度、バルク密度と同様な効果が得られる。ＪＩＳ Ｋ ５１０１−１９７８にて測定した値である。
【０１４２】
また、１（ｋＯｅ）の磁界の下で、磁性体微粉末の残留磁化が５〜２０ｅｍｕ／ｇ、飽和磁化が４０〜８０ｅｍｕ／ｇであることが好ましい。この微粉末を添加することで、特に高湿下での感光体上のカブリ低減に効果があることが判明した。感光体にカブリとして付着するトナーが磁性体添加によりトナー表面に磁性体微粉末の穂たち状態になり、これによるかきとり効果により回収され、カブリが低減されるものと思われる。
【０１４３】
トナーに添加される磁性体微粉末の表面をチタン系カップリング剤、シラン系カップリング剤、エポキシシランカップリング剤、アクルリシランカップリング剤、又はアミノシランカップリング剤により表面処理される。例えばイソプロピルトリイソステアロイルチタネート、テトラブトキシチタン、イソプロピルトリス（ジオクチルパイロホスフェート）チタネート、イソプロピルトリ（Ｎ−アミノエチルーアミノエチル）チタネート、テトラオクチルビス（ジトリデシルホスファイト）チタネート、ビス（ジオクチルパイロホスフェート）オキシアセテートチタネート、ビス（ジオクチルパイロホスフェート）エチレンチタネート、イソプロピルトリオクタノイルチタネート、イソプロピルトリオクタノイルチタネート、イソプロピルジメタクリルイソステアロイルチタネート等のチタネート系カップリング剤、ビニルトリエトキシシラン、ビニルトリス（β−メトキシエトキシ）シラン、γ−メタクリルロキシプロピルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、β−（３，４エポキシシクロヘキシル）エチルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、γ−アミノプロピルトリエトキシシラン、Ｎ−フェニルーγ−アミノプロピルトリメトキシシラン、γ−メルカプチプロピルトリメトキシシラン、γ−クロロプロピルトリメトキシシラン等のシラン系カップリング剤、γ−メタクリロキシプロピルトリメトキシシランのアクリルシランカップリング剤や、β−エチルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシランのエポキシシランカップリング剤、Ｎ−βアミノエチルγ−アミノプロピルトリメトキシシラン、Ｎ−βアミノエチルγ−アミノプロピルメチルジトキシシラン、γ−アミノプロピルトリエトキシシラン，Ｎ−フェニル−γ−アミノプロピルトリメトキシシランのアミノシランカップリング剤が表面処理される。例えば、磁性体に気化したシランカップリング剤を反応させる乾式処理、又は磁性体を溶媒中に分散させシランカップリング剤を滴下反応させる湿式法等一般に知られた方法で処理することが出来る。
【０１４４】
トナーに外添加される金属酸化物微粉末及び／又は金属酸塩微粉末の添加量がトナー母体１００重量部に対し０．１〜５重量部が好ましい。０．１より小では機能が発揮されず、５以上では耐湿性が悪化する。
【０１４５】
二成分現像剤として使用する時、キャリアは導電性微粉末を含有した樹脂で磁性体を被覆したものが好ましい。使用される導電性微粉末としては金属粉末やカーボンブラック、更に酸化チタン、酸化亜鉛などの導電性酸化物、酸化チタン、酸化亜鉛、硫酸バリウム、ホウ酸アルミニウム、チタン酸カリウム等の粉末表面を酸化スズやカーボンブラック、金属で被覆したもの等が挙げられ、その固有抵抗は１０¹⁰Ω・ｃｍ以下のものが好ましい。
【０１４６】
キャリアの芯材としては平均粒径が２０〜１００μｍ、好ましくは３０〜８０μｍ、さらに好ましくは３０〜６０μｍのマグネタイト、鉄、マンガン、コバルト、ニッケル、クロム、マグネタイト等の金属粉乃至その合金、酸化クロム、三二酸化鉄、四三酸化鉄、Ｃｕ−Ｚｎフェライト、Ｍｎ−Ｚｎフェライト、Ｂａ−Ｎｉフェライト、Ｎｉ−Ｚｎフェライト、Ｌｉ−Ｚｎフェライト、Ｍｇ−Ｍｎフェライト、Ｍｇ−Ｚｎ−Ｃｕフェライト、Ｍｎフェライト、Ｍｎ−Ｍｇフェライト、Ｌｉ−Ｍｎフェライト等が挙げられる。特にこの中で、体積抵抗率が１０⁸〜１０¹⁴Ωcmの範囲のものでＭｎフェライト、Ｍｎ−Ｍｇフェライト、Ｌｉ−Ｍｎフェライトが環境保護の面からも、また形状がＣｕ−Ｚｎ系よりも真球に近い形状となり、好ましい材料である。平均粒径が２０μｍより小となるとキャリア付着が増加する。１００μｍより大となると、高精細な画質が得にくくなる。体積抵抗率が１０⁸Ωcmより小となると、キャリア付着が増加し、１０¹⁴Ωcmより大となると現像剤のチャージアップによる画像濃度低下を生じる。
【０１４７】
キャリアの芯材に被覆層を形成するには、公知の被覆方法、例えば、キャリア芯材である粉末を、被覆層形成用溶液に浸漬する浸漬法、被覆形成用溶液をキャリア芯材の表面に噴霧するスプレー法、キャリア芯材を流動エアーにより浮遊させた状態で被覆層形成用溶液を噴霧する流動床法、ニーダーコータ中でキャリア芯材と被覆層形成用溶液を混合し、溶剤を除去するニーダーコーター法等が挙げられる。
【０１４８】
キャリアの被覆層として使用される樹脂としては、オルガノシロキサン結合からなるストレートシリコーン樹脂及びそのアルキッド変性、エポキシ変性、ウレタン変性等の変性品、フッ素樹脂、スチレン樹脂、アクリル樹脂、メタアクリル樹脂、ポリエステル樹脂、ポリアミド樹脂、エポキシ樹脂、ポリエーテル系樹脂、フェノール系樹脂等が挙げられ、これらは単独あるいは組みあわせて使用することが出来る。また共重合体としても使用することが出来る。
【０１４９】
ホホバ油誘導体を含有するトナーに対しては、シリコーン系樹脂とアクリル系の混合系の被覆層が効果的である。特に側鎖基がメチル基等の炭素数１〜４のアルキル基のみのストレートシリコーン樹脂と、側鎖基にフェニル基を含むストレートシリコーン樹脂と、（メタ）アクリル樹脂、との混合系が好ましい。
【０１５０】
シリコーン系樹脂は常温硬化型シリコーン樹脂が好ましい。例えばＫＲ２７１、ＫＲ２５５、ＫＲ１５２(信越化学社製)、ＳＲ２４００、ＳＲ２４０６、ＳＨ８４０（トーレシリコーン社製）等が挙げられる。アクリル系樹脂は、（メタ）アクリル酸、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸ブチル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸オクチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸２エチルヘキシルなどの（メタ）アクリル酸アルキルエステル重合体樹脂が好ましい。さらに、（化1）で示される炭素数１４〜２６の長鎖アルキルを有する（メタ）アクリル酸アルキル重合体からなる樹脂を被覆層として有することにより、より特性が向上する。
【０１５１】
本形態のトナーは、像担持体と導電性弾性ローラとの間に転写材を挿通させ、前記導電性弾性ローラに転写バイアス電圧を付与することにより前記像担持体上にあるトナー画像を静電気力で転写材に転写するトナー転写システムを具備する電子写真装置に好適に使用される。これは、かかるトナー転写システムは、接触転写であることから、電気力以外の機械力が転写に作用して、本来転写されるべきでない感光体表面に付着した逆極性トナーが転写されたり、通紙していない状態で感光体表面に付着したトナーが転写ローラ表面を汚染し、転写紙裏面を汚染させてしまうことがあるものである。しかしホホバ油誘導体を添加してその分散性が向上したトナー母体に、疎水性シリカ、金属酸化物微粉末、金属酸塩微粉末の添加により帯電性の安定化が得られ、さらに表面改質処理により、トナー表面に固定化処理することで、転写時の中抜けを防止でき、さらには、感光体表面へのトナーから遊離することで生じるホホバ油誘導体のフィルミングが防止できる。また、転写ローラ表面へのトナーや遊離したホホバ油誘導体のフィルミングも防止できるので、転写ローラ表面から感光体表面へトナーや遊離したホホバ油誘導体が再転写することにより生ずる画像欠陥も防止することができる。さらに低ガラス転移点トナーに使用することで、トナーの耐久性の低下をカバーすることができ、同時に貯蔵安定性と定着性、高温オフセット性との両立を図ることが可能となる。
【０１５２】
また、本形態のトナーは、転写プロセス後に像担持体上に残留したトナーを現像装置内に回収して再度現像プロセスに利用する廃トナーリサイクルシステムを具備する電子写真装置に好適に使用される。廃トナーが現像で再利用するため、クリーニング器から現像器に回収されていく間のクリーニング器、クリーニング器と現像器とを繋ぐ輸送管および現像器の内部にて機械的衝撃を受けてその添加剤が脱落したり、感光体上にフィルミングを生じてしまう。
【０１５３】
しかしホホバ油誘導体の添加してその分散性が向上したトナー母体に、疎水性シリカ、金属酸化物微粉末、金属酸塩微粉末の添加により帯電性の安定化が得られ、さらに表面改質処理により、トナー表面に固定化処理することで、長期連続使用しても帯電性安定化が図られ、トナー表面に存在するホホバ油誘導体に外添剤が打ち込まれることにより、トナーの流動性が経時的に変化することを防止する事が出来る。さらにはホホバ油誘導体の表面が外添剤により被覆されているため、脱落したり、感光体上へのフィルミングを防止する事が出来る。また現像部へリターンされて来る廃トナーの外添剤の付着状態に変化がほとんど生じないため、帯電量や流動性の変動が生じない。
【０１５４】
また、本形態のトナーは、磁性一成分トナーとしても好適に使用される。本形態に係る電子写真装置では、固定磁石を内包する静電潜像保持体を用い、静電潜像を形成した静電潜像保持体に磁性トナーを振りかけて磁気的に付着させ、トナー回収電極ローラまで担持搬送し、電極ローラに交流バイアスを印加し、静電潜像保持体の非画像部トナーを静電力と磁力によって除去することを前提とするものである。すなわち、本発明の電子写真方法は、カスケード現像法に、静電潜像保持体内部に磁石を設置し、電極に交流電圧を印加し、より小型・高性能化したものである。
【０１５５】
ところで、現像工程の構成がシンプルになっているため、トナーの帯電の機会が少なく、高帯電特性が得られにくい。また、現像時に静電潜像保持体の全面にトナーを付着させるため、従来の一成分現像法と比較してトナーと静電潜像保持体が常に全面に接触している構成で、トナーフィルミングがより発生しやすい構成である。
【０１５６】
しかしホホバ油誘導体の添加してその分散性が向上したトナー母体に、疎水性シリカ、金属酸化物微粉末、金属酸塩微粉末の添加により帯電性の安定化が得られ、さらに表面改質処理により、トナー表面に固定化処理することで、ホホバ油誘導体の表面が外添剤により被覆されているため、脱落したり、感光体上へのフィルミングを防止する事が出来る。また長期連続使用しても帯電性安定化が図られ、トナー表面に存在するホホバ油誘導体に外添剤が打ち込まれることにより、トナーの流動性が経時的に変化することを防止する事が出来き、高帯電性が得られ、高画像濃度が得られ、文字周辺のトナーの飛び散りがなく鮮明な画像が得られるわけである。
【０１５７】
また他の磁性一成分現像法にも好適に使用される。例えば現像スリーブ上に剛体の磁性ブレードや、弾性のゴム状のブレードを使用してトナーの薄層を形成し、それを感光体と接触または非接触にて直流または交流印加してトナー像を形成する現像法に好適に使用される。従来のポリエチレンやポリプロピレン等の合成系のワックスを使用したトナーでは感光体上にフィルミングを生じ易く、使用枚数に制限を設けざるをえなかったが、本形態のトナーを使用することにより、このフィルミング現象を回避でき感光体の使用寿命を高めることが可能となる。
【０１５８】
このとき磁性トナーに添加する磁性体は、具体例としては、鉄、マンガン、ニッケル、コバルトなどの金属粉末や、鉄、マンガン、ニッケル、コバルト、亜鉛、マグネタイトなどのフェライトなどがあり、先に記載した金属酸化物微粉末として使用した磁性体が好ましく使用される。
【０１５９】
添加量は５〜５０重量％が好ましく、添加量が５重量％より小ではトナー飛散が増加する傾向になり、５０重量％より大ではトナーの帯電量が低下し、画質の劣化を引き起こす傾向になる。
【０１６０】
また、本形態のトナーは、像担持体の表面に形成されたトナー画像を、前記像担持体の表面に無端状の中間転写体の表面を当接させて当該表面に前記トナー画像を転写させる一次転写プロセスが複数回繰り返し実行され、この後、この一次転写プロセスの複数回の繰り返し実行により前記中間転写体の表面に形成された重複転写トナー画像を転写材に一括転写させる２次転写プロセスが実行されるよう構成された転写システムを具備する電子写真装置に好適に使用される。ホホバ油誘導体の添加、表面改質処理や疎水性シリカをトナー表面に固定化処理することで、転写時の中抜けを防止でき、さらには、感光体表面へのトナーから遊離することで生じる低軟化点材料の中間転写体へフィルミンングが防止でき、転写紙の不要トナー粒子による汚染を防止することができる。また、転写ローラ表面から感光体表面へトナーや遊離した低軟化点材料が再転写することにより生ずる画像欠陥も防止することができる。トナー粒子同士間の相互の付着力が小さくなって、トナーの凝集が緩和されるため、トナーの凝集効果によって画像の一部が転写されずに穴となる"中抜け"現象を減少でき、転写率の低下を抑える効果も得られる。
【０１６１】
また、本形態のトナーは、回転する感光体とそれぞれ色の異なるトナーを有する現像手段とを備え前記感光体上にそれぞれ異なった色のトナー像を形成する複数の移動可能な像形成ユニットを円環状に配置した像形成ユニット群から構成され、前記像形成ユニット群全体を回転移動させ、感光体上に形成した異なる色のトナー像を転写材上に位置を合わせて重ねて転写してカラー像を形成するカラー電子写真装置に好適に使用される。像形成ユニット全体が回転する構成のため、感光体上からクリーニングされ、感光体上から離れた廃トナーが再度感光体に一時的に繰り返し付着する状況が必ず発生する。そのため低融点の合成系のワックスが不均一に分散していると、特に廃トナーにその分散不良の偏在したワックスが存在したトナーが多く存在し、その廃トナーが感光体と再度繰り返し接触することで像担持体へのフィルミングが著しく発生しやすくなり、感光体の寿命低下の要因となる。また、像形成ユニットが回転することによりトナーが上下に激しく移動するためシール部分からのトナーのこぼれが発生しやすく、そのためシール部分ではよりシールを強化する必要があり、その分散不良の偏在したワックスが存在したトナーでは、融着現象が発生し、それが塊となって黒筋、白筋の画像ノイズの原因となる。また、トナーは常に一時的に現像ローラから離脱する状況が発生し、現像初期に於いて帯電の立ち上がり性が悪いと、地カブリの原因となる。その分散不良の偏在したワックスが存在したトナーでは帯電立上り性が悪化する傾向にある。
【０１６２】
しかし、本形態のトナーではホホバ油誘導体が均一に分散されることで、帯電立上り性が改善され、感光体へのフィルミングの発生が回避され、また帯電立ち上がり性が良好であるため、現像初期の地カブリの発生は皆無である。
【０１６３】
また、本形態のトナーはフルカラー画像の定着に於いて、４色のトナーが重なり合った定着画像においても、低軟化点のポリエステルを使用しているためほぼ完全溶融に近い形で定着され、またホホバ油誘導体が高分散されているため、オイルを用いないオイルフリー定着においても良好な耐オフセットが得られ、色の濁りがない、光沢性を損ねない定着画像が得られる。
【０１６４】
上記した構成により、結着樹脂中に添加したホホバ油誘導体は定着向上剤として作用するとともに、画像表面の摩擦を低減できる効果を有し、見掛け上のトナーのガラス転移点は減少する。さらに離型剤としても十分な効果を発揮し、これにより、高分子量成分を多く含有した結着樹脂を使用しても高速時での定着強度と、低速時での耐高温オフセット性の両立が可能となり、さらには高温での貯蔵安定性も満足できる結果が得られる。よって透光性、光沢性を要求するカラー画像において、高精細な色再現性と、良好な離型効果を発揮できるため、定着機の小型化が可能となる。
【０１６５】
また、粘弾性の高い樹脂を使用して、低速機の高温オフセットを防止できるとともに、高速機での定着強度も十分確保できるため、低速機から高速機までトナーの統一が可能できる。
【０１６６】
本形態ではトナーの着色および／または電荷制御の目的で結着樹脂に適当な顔料または染料が配合される。かかる顔料または染料としては、カーボンブラック、鉄黒、グラファイト、ニグロシン、アゾ染料の金属錯体、サリチル酸金属塩、アニリンブルー、フタロシアニンブルー、フタロシアニンブルー、ハンザイエローＧ、ローダミン６Ｃレーキ、カルコオイルブルー、クロムイエロー、キナクリドン、ベンジジンイエロー、ローズベンガル、デュポンオイルレッド、トリアリルメタン系染料等を挙げることができ、これらのうちの１種または２種以上が混合されて使用される。結着樹脂に着色および／または電荷制御に必要な量が添加される。
【０１６７】
またトナーは予備混合、溶融混錬、粉砕分級、外添処理の工程を経て作成される。
【０１６８】
予備混合処理は、結着樹脂とこれに分散させるべき添加剤を撹拌羽根を具備したミキサなどにより均一分散する処理である。ミキサとしては、スーパーミキサ（川田製作所製）、ヘンシェルミキサ（三井三池工業製）、ＰＳミキサ（神鋼パンテック製）、レーディゲミキサ等の公知のミキサを使用する。
【０１６９】
溶融混練処理は、せん断力により結着樹脂中に添加剤を分散させる処理であり、シリンダと混練軸が複数のセグメントに分割された分割セグメント方式の混練機により前記した温度条件にて行われる。
【０１７０】
粉砕分級処理は、混練処理され冷却されて得られたトナー塊を、カッターミルなどで粗粉砕し、その後ジェットミル粉砕（例えばＩＤＳ粉砕機、日本ニューマティック工業）などで細かく粉砕し、さらに必要に応じて気流式分級機で微粉粒子を分別して、所望の粒度分布のトナー粒子（トナー母体粒子）を得るものである。機械式による粉砕，分級も可能であり、これには、例えば、固定したステータに対して回転するローラとの微小な空隙にトナーを投入して粉砕するクリプトロン粉砕機（川崎重工業）やターボミル（ターボ工業）などが使用される。この分級処理により一般に５〜１２μｍの範囲、好ましくは５〜９μｍの範囲の体積平均粒子径を有するトナー粒子（トナー母体粒子）を所得する。
【０１７１】
外添処理は、前記分級により得られたトナー粒子（トナー母体粒子）にシリカなどの外添剤を混合する処理である。これにはヘンシェルミキサ、スーパーミキサなどの公知のミキサが使用される。
【０１７２】
また本形態では、粉砕された粒子を所定の粒度分布にするため、分級により微粉を分別する。このとき生じた微粉を再度予備混合工程で結着樹脂等の材料と混合して再利用する。これによって産業廃棄物として廃棄されるトナーの量を減少出来るばかりでなく、トナー自体の低コスト化につながる。この微粉の再利用の際、従来から使用されているポリエチレンやポリプロピレンワックスではその分散が不均一になりやすく、カブリやトナー飛散が増大し、環境変動を受けやすくなる。しかし本形態のホホバ油誘導体の使用により分級の微粉トナーを再利用してもカブリやトナー飛散の増大は見られない。なお、予備混合工程で混合する微粉トナーとトナー母体構成材料の比が２：９８〜４０：６０の割合で作成される。この比が４０：６０より大きくなると、微粉トナーとトナー母体構成材料の混合性が低下し、分散性が向上しなくなり、画像カブリやトナー飛散が発生しやすくなる。また、この比が２：９８より小さくなると、生産性の面で効率化が満たされなくなる。さらに金属酸化物微粉末や金属酸塩微粉末の添加、表面改質処理により、現像性、環境安定性がより向上する。
【０１７３】
次に、実施例により本発明を更に詳細に説明する。
（実施例１）
（表１）に実施例で使用する結着樹脂の単量体組成を示す。
【０１７４】
【表１】

【０１７５】
（表２）に実施例で使用する結着樹脂の熱特性を示す。
【０１７６】
【表２】

【０１７７】
表２において、Ｔｇ（℃）はガラス転移点、Ｍｎは数平均分子量、Ｍｗは重量平均分子量、ＭｚはＺ平均分子量、Ｔｍ（℃）、Ｔｉ（℃）はフローテスターでの軟化点、流出開始温度である。
【０１７８】
（表３）に実施例で使用するホホバ油誘導体を内添加した結着樹脂を示す。
【０１７９】
【表３】

【０１８０】
（表４）に本実施例で使用したホホバ油誘導体を示す。
【０１８１】
【表４】

【０１８２】
（表５）に本実施例で使用した金属酸化物微粉末又は金属酸塩微粉末を示す。
【０１８３】
【表５】

【０１８４】
（表６）に本実施例で使用した疎水性シリカを示す。
【０１８５】
【表６】

【０１８６】
（表７）に本実施例で使用した磁性体微粉末を示す。
【０１８７】
【表７】

【０１８８】
表７において、Ｍｄ（μｍ）は平均粒径、Ｍｂｅｔ（ｍ2／ｇ）はＢＥＴ比表面積、Ｍｒ（Ωｃｍ）は体積抵抗、Ｍａｄ（ｇ／ｃｃ）はバルク密度、Ｍｐａｃ（％）は圧縮度、Ｍａｍ（ｍｌ／１００ｇ）はアマニ油吸油量、Ｒｒ（ｅｍｕ／ｇ）は残留磁化、Ｓｓ（ｅｍｕ／ｇ）は飽和磁化を示す。ＭＧ−４はイソプロピルトリイソステアロイルチタネートのチタネート系カップリング剤により表面処理されたサンプルである。
【０１８９】
（表８）に本実施例で使用したキャリア材料組成を示す。
【０１９０】
【表８】

【０１９１】
（表９）に本実施例で使用した電荷制御剤、顔料を示す。
【０１９２】
【表９】

【０１９３】
（表１０）に本実施例で使用したトナー材料組成を示す。
【０１９４】
【表１０】

【０１９５】
顔料、電荷制御剤、有機材料の配合量比は結着樹脂100重量部に対する配合量（重量部）比を括弧内に示す。第２外添剤は以下金属酸化物微粉末又は金属酸塩微粉末を示す。シリカ、第２外添剤はトナー母体１００重量部に対する配合量（重量部）を示している。トナーＮｏ．Ａ６、Ａ１４は予備混合工程で混合する微粉トナーとトナー母体構成材料の比を１０：９０の割合で作成している。
【０１９６】
（表１１）に本実施例で使用する表面改質処理を行ったときのトナー母体と、シリカ、表面処理温度、第２外添剤の材料組成を示す。
【０１９７】
【表１１】

【０１９８】
トナー母体は表１０記載の外添処理前の組成、シリカ１、第２外添剤１は表面改質処理を行う前のもの、シリカ２、第２外添剤２は表面改質処理を行った後のものである。
【０１９９】
表面改質処理において、原料供給量は１ｋｇ／ｈ、熱風温度は２００〜３５０℃程度、熱風風量は風圧３ｋｇ／ｃｍ²Ｇで０．３５Ｎｍ³／ｍｉｎ、原料供給分散風量は風圧１ｋｇ／ｃｍ²Ｇで０．０５Ｎｍ³／ｍｉｎで行った。熱風風量と原料供給分散風量の比は１０：１〜４：１の範囲が好ましい。
【０２００】
外添処理はＦＭ２０Ｂにおいて、攪拌羽根Ｚ０Ｓ０型、回転数２０００ｒｐｍ、処理時間５ｍｉｎ、投入量１ｋｇで行った。
【０２０１】
本実施例は二成分現像、磁性一成分現像、非磁性一成分現像、接触式、非接触式方法においても十分良好な性能を出すことが出来る。
【０２０２】
図２に本発明の電子写真方法の一実施例に用いる電子写真装置の断面図を示す。現像方式は一成分現像方式を用いている。２０１は有機感光体で、アルミニウムの導電性支持体上にポリビニルブチラール樹脂（積水化学製エレックＢＬ−１）にτ型無金属フタロシアニン（東洋インキ製）の電荷発生物質を分散した電荷発生層と、ポリカーボネート樹脂（三菱ガス化学製Ｚ−２００）と、１，１−ビス（Ｐ−ジエチルアミノフェニル）−４，４−ジフェニル−１，３−ブタジエン（アナンｊ製Ｔ−４０５）を含む電荷輸送層を順次積層した構成のものである。２０２は感光体２０１と同軸で固定された磁石、２０３は感光体２０１をマイナスに帯電するコロナ帯電器、２０４は感光体２０１の帯電電位を制御するグリッド電極、２０５は信号光である。
【０２０３】
露光後の潜像を可視像化するための現像装置の構成について、２０７は磁性一成分トナー、２０６は感光体２０１の表面に磁性トナー２０７を供給するトナーホッパー、２０８は感光体２０１とギャップを開けて設定した非磁性電極ローラ、２０９は電極ローラ２０８の内部に設置された磁石、２１０は電極ローラ２０８に電圧を印加する交流高圧電源、２１１は電極ローラ２０８上のトナーを掻き落とすポリエステルフィルム製のスクレーパである。電極ローラ２０８により、感光体２０１上での非画像部の余分なトナーを回収する。
【０２０４】
２１２はトナーホッパー２０６内でのトナー２０７の流れをスムーズにし、またトナー２０７が自重で押しつぶされ感光体２０１と電極ローラ２０８との間での詰まりが発生するのを防止するためのダンパーである。
【０２０５】
２１３は感光体上のトナー像を紙に転写する転写ローラで、その表面が感光体２０１の表面に接触するように設定されている。転写ローラ２１３は導電性の金属からなる軸の周囲に導電性弾性部材を設けた弾性ローラである。感光体２０１への押圧力は転写ローラ２１３一本（約２１６ｍｍ）当たり０〜２０００ｇ、望ましくは５００〜１０００ｇである。これは転写ローラ２１３を感光体２０１に圧接するためのバネのバネ係数と縮み量の積から測定した。感光体２０１との接触幅は約０．５ｍｍ〜５ｍｍである。転写ローラ２１３のゴム硬度はアスカーＣの測定法（ローラ形状でなく、ブロック片を用いた測定）で８０度以下で、望ましくは３０〜４０度である。弾性ローラ２１３は直径６ｍｍのシャフトの周辺にＬｉ２０などのリチウム塩を内添することによりを抵抗値を１０7 Ω（軸と表面に電極を設け、両者に５００Ｖ印加する）にした発泡性のウレタンエラストマーを用いた。転写ローラ２１３全体の外径は１６．４ｍｍで、硬度はアスカーＣで４０度であった。転写ローラ２１３を感光体２０１に転写ローラ２１３の軸を金属バネで押圧する事で接触させた。押圧力は約１０００ｇであった。ローラの弾性体としては前記発泡性のウレタンのエラストマーの他にＣＲゴム、ＮＢＲ、Ｓｉゴム、フッ素ゴムなどの他の材料からなる弾性体を使用することもできる。そして導電性を付与するための導電性付与剤としては前記リチウム塩の他にカーボンブラック等の他の導電性物質を使用することもできる。
【０２０６】
２１４は転写紙を転写ローラ２１３に導入する導電性部材からなる突入ガイド、２１５は導電性部材の表面を絶縁被覆した搬送ガイドである。突入ガイド２１４と搬送ガイド２１５は直接あるいは抵抗を介して接地している。２１６は転写紙、２１７は転写ローラ２１３に電圧印加する電圧発生電源である。２１８は転写残りのトナーを掻き落とすクリーニングゴム弾性ブレード、２１９は廃トナーを貯めるクリーニングボックスである。
【０２０７】
感光体２０１の表面での磁束密度は６００Ｇｓである。電極ローラ２０８の内部の磁力の方を強くして搬送性を向上させた。また図中に示す磁石２０２、２０９の磁極角については、θを１５度に設定した。感光体２０１の直径は３０ｍｍで、周速６０ｍｍ／ｓで図中の矢印の方向に回転させた。電極ローラ２０８の直径は１６ｍｍで、周速４０ｍｍ／ｓで感光体２０１の進行方向とは逆方向（図中の矢印方向）に回転させた。感光体２０１と電極ローラ２０８とのギャップは３００μｍに設定した。
【０２０８】
感光体２０１をコロナ帯電器２０３（印加電圧−４．５ｋＶ、グリッド４の電圧−５００Ｖ）で、−５００Ｖに帯電させた。この感光体２０１に信号光２０５を照射し静電潜像を形成した。このとき感光体２０１の露光電位は−９０Ｖであった。この感光体２０１の表面上に、磁性トナー２０７をトナーホッパー２０６内で磁石２０２の磁気吸引力により付着させた。次に感光体２０１を電極ローラ２０８の前を通過させた。感光体２０１の未帯電域の通過時には、電極ローラ２０８には交流高圧電源２１０により、０Ｖの直流電圧を重畳した７５０ＶO-P （ピーク・ツー・ピークで１．５ｋＶ）の交流電圧（周波数１ｋＨｚ）を印加した。その後、−５００Ｖに帯電し静電潜像が書き込まれた感光体２０１の通過時には、電極ローラ２０８には交流高圧電源２１０により、−３５０Ｖの直流電圧を重畳した７５０ＶO-P （ピーク・ツー・ピークで１．５ｋＶ）の交流電圧（周波数１ｋＨｚ）を印加した。すると、感光体２０１の帯電部分における非画像部に付着したトナー２０７は電極ローラ２０８に回収され、感光体２０１上には画像部のみのネガポジ反転したトナー像が残った。矢印方向に回転する電極ローラ２０８に付着したトナーは、スクレーパ２１１によって掻き取り、再びトナーホッパー２０６内に戻し、次の像形成に用いた。こうして感光体２０１上に得られたトナー像を、転写紙２１６に、転写帯電器２１３によって転写した後、定着器（図示せず）により熱定着して複写画像が得られる。（表１２）に画像テストを行った結果を示す。
【０２０９】
【表１２】

【０２１０】
画像評価は、画像形成の初期と１万枚後の耐久テスト後における、感光体へのフィルミングの発生、画像濃度、地かぶりおよび画質について行った。フィルミング、地かぶりおよび画質は目視にて判断し、実用上問題ないレベルであれば合格（○）、実用上問題があれば（×）とした。さらにその後、高湿下と低湿下に放置してそれぞれ１千枚の画像テストを行い、カブリの増加と画像濃度の低下状態を見た。
【０２１１】
この結果、トナーサンプルＡでは、横線の乱れやトナーの飛び散り、転写不良や紙の裏汚れがなく、文字の中抜けなどがなく、ベタ黒画像が画像部後端部での画像欠けがなく均一で、画像濃度１．３以上の高濃度の画像が得られた。非画像部での地かぶりも発生していなかった。１万枚の長期複写テストを行ったところ、感光体表面上でのフィルミングはなく、初期の画像に比べて遜色のない高濃度、カブリの少ない複写画像が得られた。また高湿下でのカブリの発生はなく、低湿下でも濃度低下は発生しなかった。
【０２１２】
しかしトナーサンプルＪでは、画像濃度の低下が見られ、また高湿下ではカブリの発生が多く、また低湿下でも急激な濃度低下が発生した。
【０２１３】
（実施例２）
図３は本実施例で使用した電子写真装置の構成を示す断面図である。本実施例装置は、ＦＰ７７４２（松下電器社製）複写機を反転現像用に改造し、廃トナーリサイクル機構を付加した構成である。
【０２１４】
３０１は有機感光体で、アルミニウムの導電性支持体上にオキソチタニウムフタロシアニンの粉末を蒸着により電荷発生層を形成し、その上にポリカーボネート樹脂（三菱ガス化学製Ｚ−２００）と、ブタジエンとヒドラゾンの混合物を含む電荷輸送層を順次積層した構成のものである。３０２は感光体をマイナスに帯電するコロナ帯電器、３０３は感光体の帯電電位を制御するグリッド電極、３０４は信号光である。３０５は現像スリーブ、３０６はドクターブレード、３０７はキャリア保持のためのマグネットロール、３０８はキャリア、３０９はトナー、３１０は電圧発生装置、３１１は転写残りの廃トナー、３１２はクリーニングボックス、３１３はクリーニングボックス３１２中の廃トナー３１１を現像工程に戻すための輸送管である。転写残りのトナーをクリーニングブレード３１４でかき落とし、クリーニングボックス３１２に一時的に貯められた廃トナー３１１は、輸送管３１３によって現像工程に戻されるよう構成されている。
【０２１５】
３１４は感光体上のトナー像を紙に転写する転写ローラで、その表面が感光体３０１の表面に接触するように設定されている。転写ローラ３１４は導電性の金属からなる軸の周囲に導電性弾性部材を設けた弾性ローラである。基本的な条件は実施例1と同様である。
【０２１６】
３１５は転写紙を転写ローラ３１４に導入する導電性部材からなる突入ガイド、３１６は導電性部材の表面を絶縁被覆した搬送ガイドである。突入ガイド３１５と搬送ガイド３１６は直接あるいは抵抗を介して接地している。３１７は転写紙、３１８は転写ローラ３１４に電圧印加する電圧発生電源である。（表１３）に画像テストを行った結果を示す。
【０２１７】
【表１３】

【０２１８】
画像評価は、画像形成の初期と２０万枚後の耐久テスト後における、感光体へのフィルミングの発生、画像濃度、地かぶりおよび画質について行った。フィルミング、地かぶりおよび画質は目視にて判断し、実用上問題ないレベルであれば合格（○）とした。その後、高湿下に放置して１千枚の画像テストを行い、カブリの増加を見た。トナー濃度制御が不良となり、オーバートナーになるとカブリが急増するため、その状態を観察した。さらに別実験にて高温低湿下に一晩放置し、次の日５千枚の画像テストを行い、５千枚後の画像濃度を示す。
【０２１９】
トナーサンプルＡでは、横線の乱れやトナーの飛び散り、転写不良や紙の裏汚れがなく、文字の中抜けなどがなく、ベタ黒画像が画像部後端部での画像欠けがなく均一で、画像濃度１．３以上の高濃度の画像が得られた。非画像部での地かぶりも発生していなかった。更に、２０万枚の長期複写テストを行ったところ、また感光体表面上でのフィルミングはなく、初期の画像に比べて遜色のない高濃度、低地カブリの複写画像が得られた。また高湿下でのカブリの発生はなく、高温低湿下でも濃度低下は発生しなかった。しかしトナーサンプルＪでは、画像濃度の低下が見られ、また高湿下ではトナー濃度がオーバーに走りカブリの発生が多く、また高温低湿下でも急激な濃度低下が発生した。
【０２２０】
トナーサンプルＡを用いて、ＦＰ−７７５０（松下電器社製）、ＦＰ７７２２（松下電器社製）複写機を改造し、プロセス速度を１４０ｍｍ／ｓｅｃ（低速）での高温オフセット性と、４５０ｍｍ／ｓｅｃ（高速）での定着率の定着性評価を行った。（表１４）に画像テストを行った結果を示す。
【０２２１】
【表１４】

【０２２２】
トナーサンプルＡでは、高速での定着性と、低速での耐高温オフセット性と、高温保存性テストにおいて、実用上十分満足する性能が得られた。
【０２２３】
定着率は８０％以上、オフセット性は２００℃以上を合格レベルとした。定着率は画像濃度１．０±０．２のパッチを各列毎に、ベンコット（旭化成社製商標）を巻いた５００ｇ（φ３６ｍｍ）の錘で１０往復擦過し、擦過前後の画像濃度をマクベス反射濃度計にて測定し、その変化率で定義した。８０％以上を合格とした。保存性テストでは５０℃、２４時間放置後の固まり状態で評価した。×はかなり固まり、実用上ＮＧ、△はすこし固くなるが実用上問題無し。○ほとんど固まらずと評価した。
【０２２４】
（実施例３）
図４は本実施例で使用したフルカラー画像形成用の電子写真装置の構成を示す断面図である。図４において、１はカラー電子写真プリンタの外装筐で、図中の右端面側が前面である。１Ａはプリンタ前面板であり、この前面板１Ａはプリンタ外装筐１に対して下辺側のヒンジ軸１Ｂを中心に点線表示のように倒し開き操作、実線表示のように起こし閉じ操作自由である。プリンタ内に対する中間転写ベルトユニット２の着脱操作や紙詰まり時などのプリンタ内部点検保守等は前面板１Ａを倒し開いてプリンタ内部を大きく解放することにより行われる。この中間転写ベルトユニット２の着脱動作は、感光体の回転軸母線方向に対し垂直方向になるように設計されている。
【０２２５】
中間転写ベルトユニット２の構成を図５に示す。中間転写ベルトユニット２はユニットハウジング２ａに、中間転写ベルト３、導電性弾性体よりなる第１転写ローラ４、アルミローラよりなる第２転写ローラ５、中間転写ベルト３の張力を調整するテンションローラ６、中間転写ベルト３上に残ったトナー像をクリーニングするベルトクリーナローラ７、クリーナローラ７上に回収したトナーをかきおとすスクレーパ８、回収したトナーを溜おく廃トナー溜め９ａおよび９ｂ、中間転写ベルト３の位置を検出する位置検出器１０を内包している。この中間転写ベルトユニット２は、図４に示されているように、プリンタ前面板１Ａを点線のように倒し開いてプリンタ外装筐１内の所定の収納部に対して着脱自在である。
【０２２６】
中間転写ベルト３は、絶縁性樹脂中に導電性のフィラーを混練して押出機にてフィルム化して用いる。本実施例では、絶縁性樹脂としてポリカーボネート樹脂（たとえば三菱ガス化学製，ユーピロンＺ３００）９５重量部に、導電性カーボン（たとえばケッチェンブラック）５重量部を加えてフィルム化したものを用いた。また、表面に弗素樹脂をコートした。フィルムの厚みは約３５０μｍ、抵抗は約１０⁷〜１０⁸Ω・ｃｍである。ここで、中間転写ベルト３としてポリカーボネート樹脂に導電性フィラーを混練し、これをフィルム化したものを用いているのは、中間転写ベルト３の長期使用による弛みや，電荷の蓄積を有効に防止できるようにするためであり、また、表面を弗素樹脂でコートしているのは、長期使用による中間転写ベルト表面へのトナーフィルミングを有効に防止できるようにするためである。
【０２２７】
この中間転写ベルト３を、厚さ１００μｍのエンドレスベルト状の半導電性のウレタンを基材としたフィルムよりなり、周囲に１０⁷Ω・cmの抵抗を有するように低抵抗処理をしたウレタンフォームを成形した第１転写ローラ４、第２転写ローラ５およびテンションローラ６に巻回し、矢印方向に移動可能に構成する。ここで、中間転写ベルト３の周長は、最大用紙サイズであるＡ４用紙の長手方向の長さ（２９８ｍｍ）に、後述する感光体ドラム（直径３０ｍｍ）の周長の半分より若干長い長さ（６２ｍｍ）を足した３６０ｍｍに設定している。
【０２２８】
中間転写ベルトユニット２がプリンタ本体に装着されたときには、第１転写ローラ４は、中間転写ベルト３を介して感光体１１（図５に図示）に約１．０ｋｇの力で圧接され、また、第２転写ローラ５は、中間転写ベルト３を介して上記の第１転写ローラ４と同様の構成の第３転写ローラ１２（図５に図示）に圧接される。この第３転写ローラ１２は中間転写ベルト３に従動回転可能に構成している。
【０２２９】
クリーナローラ７は、中間転写ベルト３を清掃するベルトクリーナ部のローラである。これは、金属性のローラにトナーを静電的に吸引する交流電圧を印加する構成である。なお、このクリーナローラ７はゴムブレードや電圧を印加した導電性ファーブラシであってもよい。
【０２３０】
図４において、プリンタ中央には黒、シアン、マゼンタ、イエロの各色用の４組の扇型をした像形成ユニット１７Ｂｋ、１７Ｙ、１７Ｍ、１７Ｃが像形成ユニット群１８を構成し、図のように円環状に配置されている。各像形成ユニット１７Ｂｋ、１７Ｙ、１７Ｍ、１７Ｃは、プリンタ上面板１Ｃをヒンジ軸１Ｄを中心に開いて像形成ユニット群１８の所定の位置に着脱自在である。像形成ユニット１７Ｂｋ、１７Ｙ、１７Ｍ、１７Ｃはプリンタ内に正規に装着されることにより、像形成ユニット側とプリンタ側の両者側の機械的駆動系統・電気回路系統が相互カップリング部材（不図示）を介して結合して機械的・電気的に一体化する。
【０２３１】
円環状に配置されている像形成ユニット１７Ｂｋ、１７Ｃ、１７Ｍ、１７Ｙは支持体（図示せず）に支持されており、全体として移動手段である移動モータ１９に駆動され、固定されて回転しない円筒状の軸２０の周りに回転移動可能に構成されている。各像形成ユニットは、回転移動によって順次前述の中間転写ベルト３を支持する第２転写ローラ４に対向した像形成位置２１に位置することができる。像形成位置２１は信号光２２による露光位置でもある。
【０２３２】
各像形成ユニット１７Ｂｋ、１７Ｃ、１７Ｍ、１７Ｙは、中に入れた現像剤を除きそれぞれ同じ構成部材よりなるので、説明を簡略化するため黒用の像形成ユニット１７Ｂｋについて説明し、他色用のユニットの説明については省略する。３５はプリンタ外装筐１内の下側に配設したレーザビームスキャナ部であり、図示しない半導体レーザ、スキャナモータ３５ａ、ポリゴンミラー３５ｂ、レンズ系３５ｃなどから構成されている。このレーザビームスキャナ部３５からの画像情報の時系列電気画素信号に対応した画素レーザ信号光２２は、像形成ユニット１７Ｂｋと１７Ｙの間に形成された光路窓口３６を通って、軸２０の一部に開けられた窓３７を通して軸２０内の固定されたミラー３８に入射し、反射されて像形成位置２１にある像形成ユニット１７Ｂｋの露光窓２５から像形成ユニット１７Ｂｋ内にほぼ水平に進入し、像形成ユニット内に上下に配設されている現像剤溜め２６とクリーナ３４との間の通路を通って感光体１１の左側面の露光部に入射し母線方向に走査露光される。
【０２３３】
ここで光路窓口３６からミラー３８までの光路は両隣の像形成ユニット１７Ｂｋと１７Ｙとのユニット間の隙間を利用しているため、像形成ユニット群１８には無駄になる空間がほとんど無い。また、ミラー３８は像形成ユニット群１８の中央部に設けられているため、固定された単一のミラーで構成することができ、シンプルでかつ位置合わせなどが容易な構成である。
【０２３４】
１２はプリンタ前面板１Ａの内側で紙給送ローラ３９の上方に配設した第３転写ローラであり、中間転写ベルト３と第３転写ローラ１２との圧接されたニップ部には、プリンタ前面板１Ａの下部に設けた紙給送ローラ３９により用紙が送られてくるように用紙搬送路が形成されている。
【０２３５】
４０はプリンタ前面板１Ａの下辺側に外方に突出させて設けた給紙カセットであり、複数の紙Ｓを同時にセットできる。４１ａと４１ｂとは紙搬送タイミングローラ、４２ａ・４２ｂはプリンタの内側上部に設けた定着ローラ対、４３は第３転写ローラ１２と定着ローラ対４２ａ・４２ｂ間に設けた紙ガイド板、４４ａ・４４ｂは定着ローラ対４２ａ・４２ｂの紙出口側に配設した紙排出ローラ対、４５は定着ローラ４２ａに供給するシリコンオイル４６を溜める定着オイル溜め、４７はシリコンオイル４６を定着ローラ４２ａに塗布するオイル供給ローラである。
【０２３６】
各像形成ユニット１７Ｂｋ、１７Ｃ、１７Ｍ、１７Ｙ、中間転写ベルトユニット２には、廃トナー溜めを設けている。
【０２３７】
以下、動作について説明する。
最初、像形成ユニット群１８は、図４に示すように、黒の像形成ユニット１７Ｂｋが像形成位置２１にある。このとき感光体１１は中間転写ベルト３を介して第１転写ローラ４に対向接触している。
【０２３８】
像形成工程により、レーザビームスキャナ部３５により黒の信号光が像形成ユニット１７Ｂｋに入力され、黒トナーによる像形成が行われる。このとき像形成ユニット１７Ｂｋの像形成の速度（感光体の周速に等しい６０ｍｍ／ｓ）と中間転写ベルト３の移動速度は同一になるように設定されており、像形成と同時に第１転写ローラ４の作用で、黒トナー像が中間転写ベルト３に転写される。このとき第１転写ローラには＋１ｋＶの直流電圧を印加した。黒のトナー像がすべて転写し終わった直後に、像形成ユニット１７Ｂｋ、１７Ｃ、１７Ｍ、１７Ｙは像形成ユニット群１８として全体が移動モータ１９に駆動されて図中の矢印方向に回転移動し、ちょうど９０度回転して像形成ユニット１７Ｃが像形成位置２１に達した位置で止まる。この間、像形成ユニットの感光体以外のトナーホッパ２６やクリーナ３４の部分は感光体１１先端の回転円弧より内側に位置しているので、中間転写ベルト３が像形成ユニットに接触することはない。
【０２３９】
像形成ユニット１７Ｃが像形成位置２１に到着後、前と同様に今度はシアンの信号でレーザビームスキャナ部３５が像形成ユニット１７Ｃに信号光２２を入力しシアンのトナー像の形成と転写が行われる。このときまでに中間転写ベルト３は一回転し、前に転写された黒のトナー像に次のシアンのトナー像が位置的に合致するように、シアンの信号光の書き込みタイミングが制御される。この間、第３転写ローラ１２とクリーナローラ７とは中間転写ベルト３から少し離れており、転写ベルト上のトナー像を乱さないように構成されている。
【０２４０】
以上と同様の動作を、マゼンタ、イエロについても行い、中間転写ベルト３上には４色のトナー像が位置的に合致して重ね合わされカラー像が形成された。最後のイエロトナー像の転写後、４色のトナー像はタイミングを合わせて給紙カセット４０から送られる用紙に、第３転写ローラ１２の作用で一括転写される。このとき第２転写ローラ５は接地し、第３転写ローラ１２には＋１．５ｋＶの直流電圧を印加した。用紙に転写されたトナー像は定着ローラ対４２ａ・４２ｂにより定着された。用紙はその後排出ローラ対４４ａ・４４ｂを経て装置外に排出された。中間転写ベルト３上に残った転写残りのトナーは、クリーナローラ７の作用で清掃され次の像形成に備えた。
【０２４１】
次に単色モード時の動作を説明する。単色モード時は、まず所定の色の像形成ユニットが像形成位置２１に移動する。次に前と同様に所定の色の像形成と中間転写ベルト３への転写を行い、今度は転写後そのまま続けて、次の第３転写ローラ１２により給紙カセット４０から送られてくる用紙に転写をし、そのまま定着した。
【０２４２】
なお、本装置では、像形成ユニットの構造としてはコンベンショナルな現像法を用いた構造の像形成ユニットを用いることもできる。 （表１５)に本実施例において使用するトナーの処方を示す。
【０２４３】
【表１５】

【０２４４】
図４の電子写真装置により、画像を形成した。かかる電子写真装置により、前記のように製造したトナーサンプルを用いて画像出しを行ったところ、横線の乱れやトナーの飛び散り、文字の中抜けなどがなくベタ黒画像が画像部後端部での画像欠けがなく均一で、１６本／ｍｍの画線をも再現した極めて高解像度高画質の画像が得られ、画像濃度１．３以上の高濃度の画像が得られた。また、非画像部の地かぶりも発生していなかった。更に、１万枚の長期耐久テストにおいても、流動性、画像濃度とも変化が少なく安定した特性を示した。また転写においても中抜けは実用上問題ないレベルであり、転写効率は９０％であった。また、感光体、中間転写ベルトへのトナー（離型剤）のフィルミングも実用上問題ないレベルであった。
【０２４５】
（表１６）にＯＨＰ用紙に付着量０．７ｍｇ／ｃｍ2以上のベタ画像を１７０℃で、オイルを塗布しない定着器で定着させたときの透過率と、高温でのオフセット性を評価した。プロセス速度は１００ｍｍ／ｓｅｃで、透過率は分光光度計Ｕ−３２００（日立製作所）で、７００ｎｍの光の透過率を測定した。実用上満足できる結果が得られた。
【０２４６】
【表１６】

【０２４７】
【発明の効果】
以上のように、本発明によれば、結着樹脂中におけるワックス等の内添加剤の分散性を向上させ、非画像部へのカブリの発生、ベタ黒画像部後端部での画像欠け、および、感光体へのフィルミングの発生を防止することができる。
また、本発明によれば、分級で分別された微粉トナーを混合で再利用しても安定した画像が得られる。
【図面の簡単な説明】
【図１】本発明のトナーに使用される表面改質処理装置の一例の構成を概要的に示した断面図
【図２】本発明の実施例で使用した一成分現像の電子写真装置の構成を示す断面図
【図３】本発明の実施例で使用した電子写真装置の構成を示す断面図
【図４】本発明の実施例で使用したカラー電子写真装置の概略構成を示す断面図
【図５】図４に示した中間転写ベルトユニットの構成を示す断面図
【図６】カラー電子写真装置の概略構成を示す断面図
【符号の説明】
２ 中間転写ベルトユニット
３ 中間転写ベルト
４ 第１転写ローラ
５ 第２転写ローラ
６ テンションローラ
１１ 感光体
１２ 第３転写ローラ
１７Ｂｋ，１７Ｃ，１７Ｍ，１７Ｙ 像形成ユニット
１８ 像形成ユニット群
２１ 像形成位置
２２ レーザ信号光
３５ レーザビームスキャナ部
３８ ミラー
１０３ 圧縮空気
１０４ 分散ノズル
１０５ 熱風発生装置
１０９ 冷却空気
１１０ サイクロン
１１３ 風量計
２０１ 感光体
２０３ コロナ帯電器
２０４ グリッド電極
２０７ トナー
２０８ 現像スリーブ
２１３ 転写ローラ
２１４ 突入ガイド
２１５ 搬送ガイド
２１６ 転写紙
２１８ クリーニングブレード
２１９ クリーニングボックス
３０８ キャリア
３０５ 現像スリーブ
３０６ ドクターブレード
３０７ マグネットロール
３１４ クリーニングブレード
３１２ クリーニングボックス
３１１ 廃トナー
３１３ 廃トナー輸送管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a copying machine, a laser beam printer (LBP), a facsimile (FAX), a color copying machine, a toner used for a color LBP and a color FAX, and an electrophotographic apparatus.
[0002]
[Prior art]
In recent years, electrophotographic apparatuses are shifting from the purpose of office use to personal use, and there is a demand for technology that realizes downsizing, maintenance-free, and the like. Therefore, conditions such as good maintainability such as recycling of waste toner and less ozone exhaust are required.
[0003]
The printing process of electrophotographic copying machines and printers will be described. First, an image carrier (hereinafter referred to as a photoreceptor) is charged for image formation. As a charging method, a photoreceptor using a conventionally used corona charger, or a contact-type charging method in which a conductive roller is directly pressed against the photoreceptor in recent years with the aim of reducing the amount of ozone generated. There is a method for uniformly charging the surface. In the case of a copying machine, after charging the photosensitive member, the copy original is irradiated with light and the reflected light is irradiated onto the photosensitive member through the lens system. Alternatively, in the case of a printer, an image signal is sent to a light emitting diode or laser diode as an exposure light source, and a latent image is formed on the photosensitive member by turning on and off the light. When a latent image (surface potential level) is formed on the photoconductor, the photoconductor is visualized with toner (a diameter of about 5 μm to 15 μm) which is a pre-charged colored powder. The toner adheres to the surface of the photoconductor according to the level of the surface potential of the photoconductor and is electrically transferred to a copy sheet. That is, the toner is charged positively or negatively in advance, and is electrically attracted by applying a charge having a polarity opposite to the toner polarity from the back surface of the copy paper. As a transfer method, a transfer method using a conventionally used corona discharger, or a transfer method in which a conductive roller is directly pressed against a photoconductor in order to reduce the amount of ozone generated has been put into practical use. At the time of transfer, not all of the toner on the photoreceptor is transferred to the copy sheet, but a part of the toner remains on the photoreceptor. This residual toner is scraped off by a cleaning blade or the like at the cleaning unit to become waste toner. The toner transferred to the copy paper is fixed to the paper by heat and pressure in the fixing process.
[0004]
As a fixing method, there are a pressure fixing method for passing between two or more metal rolls, an oven fixing method for passing through a heating atmosphere by an electric heater, and a hot roll fixing method for passing between heating rollers. In the heat roll fixing method, since the surface of the heating roller and the toner surface on the copy paper are in pressure contact, the thermal efficiency when fusing the toner image to the copy paper is good, and the fixing can be performed quickly. However, in the heat roll fixing method, the toner is brought into pressure contact with the surface of the heating roller in a heated and melted state, so that a part of the toner adheres to the surface of the roller and again adheres to the copy paper, which tends to cause an offset phenomenon. As a method for preventing the offset, the surface of the heating roller is made of a heat-resistant, fluororesin or silicone rubber that is excellent in releasability with respect to the toner, and an offset prevention liquid such as silicone oil is supplied to the surface to form a thin liquid film. A method of coating the roller surface has been taken. In this method, a liquid such as silicone oil is heated to generate an odor, and an extra device for supplying the liquid is required, which complicates the mechanism of the copying apparatus. Also, in order to prevent offset with high stability, it is necessary to control the supply of liquid with high accuracy, and the copying apparatus must be expensive. Therefore, there is a demand for a toner that does not cause an offset even if such a liquid is not supplied and that can provide a good fixed image.
[0005]
As is well known, toners for electrostatic charge development used in electrophotographic methods are generally resin components, coloring components composed of pigments or dyes, plasticizers, charge control agents, and if necessary, release agents. It is comprised by the additional component. As the resin component, natural or synthetic resins may be used alone or mixed in a timely manner.
[0006]
Then, the above additives are premixed at an appropriate ratio, heated and kneaded by heat melting, finely pulverized by an airflow type impact plate method, and finely classified to complete a toner base. Thereafter, an external additive is added to the toner base to complete the toner.
[0007]
In one-component development, the toner is composed only of toner, but a two-component developer can be obtained by mixing with toner and a carrier made of magnetic particles.
[0008]
In a color copying machine, the photosensitive member is charged by corona discharge using a charging charger, and then a latent image of each color is irradiated to the photosensitive member as an optical signal to form an electrostatic latent image, and a first color, for example, yellow toner is used. Develop and visualize the latent image. Thereafter, a transfer material charged with a polarity opposite to that of the yellow toner is brought into contact with the photoconductor to transfer the yellow toner image formed on the photoconductor. The photosensitive member is neutralized after cleaning the toner remaining at the time of transfer, and the development and transfer of the first color toner are completed.
[0009]
Thereafter, the same operation as yellow toner is repeated for toners such as magenta and cyan, and a color image is formed by superimposing toner images of respective colors on a transfer material. These superimposed toner images are transferred to a transfer sheet charged with a polarity opposite to that of the toner, then fixed, and copying is completed.
[0010]
In this color image forming method, a toner image of each color is sequentially formed on a single photoconductor, and a transfer material wound around a transfer drum is rotated and repeatedly opposed to the photoconductor, and each color formed sequentially there A transfer drum system in which toner images are transferred in an overlapping manner, and a plurality of image forming portions are arranged side by side, and each color forming toner image is sequentially transferred to a transfer material conveyed by a belt through each image forming portion, A continuous superposition method in which color images are superposed is common.
[0011]
A color image forming apparatus disclosed in Japanese Patent Laid-Open No. 1-252882 is one that uses the transfer drum system. FIG. 6 shows an outline of the overall configuration of this conventional example. The configuration and operation will be briefly described below. In FIG. 6, reference numeral 501 denotes a photoconductor, which is provided with a charger 502, a developing unit 503, a transfer drum 504, and a cleaner 505 so as to face each other. The developing unit 503 includes a Y developing unit 506 for forming a yellow toner image, a magenta M developing unit 507, a cyan C developing unit 508, and a black Bk developing unit 509, and the entire developing unit group. , And each developing device sequentially faces the photosensitive member 501 and is ready for development. The transfer drum 504 and the photoconductor 501 rotate at a constant speed in the direction of the arrow while facing each other during operation.
[0012]
When the image forming operation starts, the photosensitive member 501 rotates in the direction of the arrow and the surface thereof is uniformly charged by the charger 502. Thereafter, the surface of the photoreceptor is irradiated with a laser beam 510 modulated with a signal for forming a yellow image of the first color to form a latent image. Next, the latent image is first developed by the Y developing unit 506 facing the photoconductor 501 to form a yellow toner image. By the time the yellow toner image formed on the photoconductor moves to a position facing the transfer drum 504, one sheet of transfer material sent from the paper supply unit 511 has already been placed on the outer periphery of the transfer drum 504. The front end is gripped by the claw portion 512 and wound, and the timing is set so that the yellow toner image on the photoconductor faces the predetermined position of the sheet.
[0013]
After the yellow toner image on the photoconductor is transferred to the paper by the action of the transfer charger 513, the surface of the photoconductor is cleaned by the cleaner 505, and the next color image formation is prepared. Subsequently, magenta, cyan, and black toner images are formed in the same manner. At this time, the developing unit 503 makes the developing units 506 to 509 used in accordance with the colors face the photoconductor so that they can be developed. The diameter of the transfer drum 504 is large enough to allow the longest paper to be wound around and to replace the developing device between the images of the respective colors.
[0014]
The irradiation of the laser beam 510 for image formation of each color is timed so that the toner image of each color on the photosensitive member and the toner image already transferred onto the paper on the transfer drum are positioned and matched with each other as they rotate. Is taken and executed. In this manner, the four color toner images are transferred onto the paper on the transfer drum 504, and a color image is formed on the paper. After all color toner images have been transferred, the sheet is peeled off from the transfer drum 504 by a peeling claw 514, and the toner image is fixed by a fixing unit 516 through a transport unit 515, and discharged outside the apparatus.
[0015]
On the other hand, as an example of a color image forming apparatus using a continuous transfer system, there is JP-A-1-250970. In this conventional example, four image forming stations each including a photoconductor and an optical scanning unit are arranged for forming four color images, and the sheet conveyed to the belt passes through the lower part of each photoconductor to form a color. The toner images are superimposed.
[0016]
Furthermore, as another method for forming a color image by superimposing different color toner images on a transfer material, the respective color toner images sequentially formed on the photosensitive member are once superimposed on an intermediate transfer material, and finally this intermediate image is finally obtained. JP-A-2-212867 discloses a method for transferring toner images on a transfer material to transfer paper in a lump.
[0017]
[Problems to be solved by the invention]
Recently, from the viewpoint of protecting the global environment, it is possible to reduce the amount of ozone generated, to recycle waste toner that has not been reused in the past to regulate unlimited disposal of industrial waste, and to reduce the power consumption of fixing. There is a need for low-temperature fixing methods that can be suppressed. Toner materials are also being improved to cope with a roller transfer method with less ozone generation, waste toner recycling, and low-temperature fixing. Further, high-performance toners that can be satisfied at the same time, not individually, are an important issue for environmental protection.
[0018]
Also, different types of toner are used for each model having different process speeds in copying machines, printers, and fax machines. For example, a low speed machine uses a binder resin material having a high viscoelasticity and a high softening point in order to improve the offset resistance. Since it is difficult to obtain the amount of heat necessary for fixing in a high-speed machine, another binder resin having a different softening point is used in order to improve the fixing property. The process speed is related to the copying processing capacity of the machine per hour and indicates the peripheral speed of the photosensitive member. The conveyance speed of the copy paper is determined by the peripheral speed of the photosensitive member. If these separate toners can be shared, production efficiency can be increased and toner costs can be greatly reduced.
[0019]
In the fixing process, the fixing strength which is the adhesion force of the toner to the paper and the anti-offset property which prevents the adhesion to the heat roller are the controlling factors.
[0020]
The toner melts and penetrates into the fiber of the paper by heat or pressure from the fixing roller to obtain a fixing strength. In order to improve this fixing characteristic, conventionally, the binder resin has been improved or a release agent has been added to increase the fixing strength to be fixed to the paper and prevent the offset phenomenon that the toner adheres to the fixing roller. is doing.
[0021]
In Japanese Patent Laid-Open No. 59-148067, a polyolefin having a low molecular weight and a high molecular weight portion in a resin, an unsaturated ethylene polymer having a low molecular weight peak value and Mw / Mn defined, and a softening point specified. Toners containing are disclosed. As a result, fixing property and offset resistance are ensured. JP-A-56-158340 discloses a toner mainly composed of a resin comprising a specific low molecular weight polymer component and a high molecular weight polymer component. The purpose is to secure the fixing property by the low molecular weight component and ensure the offset resistance by the high molecular weight component. JP-A-58-223155 discloses a resin composed of an unsaturated ethylene polymer having a maximum value in a molecular weight region of 1000 to 10,000 and 200,000 to 1,000,000 and Mw / Mn of 10 to 40 and a specific softening. Toners containing polyolefins with dots are disclosed. It is used for the purpose of securing fixability with a low molecular weight component and ensuring offset resistance with a high molecular weight component and polyolefin.
[0022]
However, in order to increase the fixing strength in a high-speed machine, if a resin whose binder resin has a low melt viscosity or a low molecular weight is used, the so-called spent that the toner adheres to the carrier during long-term use can be generated. It tends to occur. In the case of one-component development, the toner is easily fixed on the doctor blade or the development sleeve, and the stress resistance of the toner is lowered. Further, when used in a low speed machine, an offset in which toner adheres to the heat roller during fixing tends to occur. Further, blocking occurs in which the toners are fused during long-term storage.
[0023]
Depending on the blending of high and low molecular weight components, it is possible to achieve both fixing strength and offset resistance for a narrow range of process speeds, but it is difficult to accommodate a wide range of process speeds. . In order to cope with a wide range of process speeds, a certain degree of effect can be exhibited by configuring a higher molecular weight component and a lower low molecular weight component. However, the fixing strength can be increased by increasing the low molecular weight component in the high speed machine, but the offset resistance is deteriorated, and the effect of increasing the offset resistance can be obtained by increasing the high molecular weight component in the low speed machine. If the amount of the high molecular weight component is increased, adverse effects such as a decrease in the pulverization property of the toner and a decrease in productivity occur.
[0024]
Therefore, low melting point release agents, such as polyethylene and polypropylene wax, improve the releasability from the heat roller at the time of fixing for a structure in which a high molecular weight component and a low molecular weight component are blended or copolymerized. It is added for the purpose of enhancing the offset resistance.
[0025]
However, these release agents are generally difficult to improve the dispersibility in the binder resin, easily generate reverse polarity toner due to poor dispersion, and cause fogging on non-image areas. In addition, an image chipped like a stroke is generated at the rear end portion of the solid black image portion, and the image quality is deteriorated. There is also a problem of filming contamination of the photoreceptor.
[0026]
In addition, in JP-A-5-119509 and JP-A-8-220808, it is reported that excellent fixability and offset resistance are obtained by adding a large amount of carnauba wax to suppress color turbidity. ing.
[0027]
By the way, even when carnauba wax is added, there are problems similar to those of the polyethylene wax and polypropylene wax.
[0028]
On the other hand, the toner is prepared by a premixing process, a kneading process, a crushing process, a classification process, and an external addition process in the manufacturing process. The classification process is a process for classifying the fine powder toner and setting the particle size distribution to a predetermined value. The separated fine powder toner is currently discarded. This is because the fog increases when this is used again for mixing. In particular, the fog increases more remarkably in polypropylene and polyethylene wax added to improve releasability. Therefore, if the fine toner generated at 10 to 20% can be reused by mixing, it will lead to effective utilization of resources.
[0029]
  In view of the above problems, the present invention improves the dispersibility of the internal additive such as wax in the binder resin, generates fog in the non-image area, the image lack at the rear end of the solid black image area, and Prevent filming on the photoconductorTonerThe purpose is to provide.
[0030]
  Further, the present invention can provide a stable image even if the fine powder toner classified by classification is reused by mixing.TonerThe purpose is to provide.
[0031]
[Means for Solving the Problems]
  The first configuration of the toner according to the present invention is at leastThe weight average molecular weight Mw is 10,000 to 300,000, the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn is 3 to 50, the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 10 to 800, high Includes polyester resin obtained by polycondensation of polyhydric carboxylic acid or its lower alkyl ester and polyhydric alcohol whose 1/2 outflow temperature by chemical flow tester is 80 to 150 ° C. and outflow start temperature is 80 to 120 ° C.A toner base having a binder resin, a colorant, and a jojoba oil derivative, and an external additive.MukoAnd features.
[0032]
  The second configuration of the toner according to the present invention is as follows.The weight average molecular weight Mw is 10,000 to 300,000, the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn is 3 to 50, the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 10 to 800, high Includes polyester resin obtained by polycondensation of polyhydric carboxylic acid or its lower alkyl ester and polyhydric alcohol whose 1/2 outflow temperature by chemical flow tester is 80 to 150 ° C. and outflow start temperature is 80 to 120 ° C.A binder resin, an average particle diameter of 0.02 to 2.0 μm, and a ratio D25 / D75 of 25% residual diameter D25 to 75% residual diameter D75 is in the range of 1.3 to 1.7; BET specific surface area by 0.5 ~ 80m²/ G and an electrical resistance of 10²-10¹¹Ωcm, bulk density of 0.3 to 0.9 g / cc, compression rate of 30 to 80%, linseed oil absorption of 10 to 30 (ml / 100 g), and residual magnetization of 5 to 20 emu / g, a magnetic material having a saturation magnetization of 40 to 80 emu / g, a toner base having a jojoba oil derivative, and an external additive.
[0033]
  furtherThe present inventionIn the first or second configuration, the jojoba oil derivative is,Jojoba oil derivative is jojoba oil fatty acid, metal salt of jojoba oil fatty acid, jojoba oil fatty acid ester, hydrogenated jojoba oil, jojoba oil amide, homo jojoba oil amide, jojoba oil triester, maleic acid derivative of epoxidized jojoba oil, jojoba oil It is one or more selected from the group consisting of isocyanate polymers of fatty acid polyhydric alcohol estersIt is characterized by that.
[0047]
  Furthermore, the present inventionJojoba oil derivative in the first or second configurationThe jojoba oil triester is a jojoba oil triester obtained by epoxidizing jojoba oil and acylating it after hydration ring opening.
[0048]
  Furthermore, the present inventionJojoba oil derivative in the first or second configurationThe metal salt of jojoba oil fatty acid is a metal salt of sodium, potassium, calcium, magnesium, barium, zinc, lead, manganese, iron, nickel, cobalt, and aluminum.
[0050]
  Furthermore, the present inventionSecond configurationThe magnetic material is treated with at least one coupling agent selected from a titanium coupling agent, a silane coupling agent, an epoxy silane coupling agent, an acrylic silane coupling agent, or an aminosilane coupling agent. Features.
[0057]
  Furthermore, the present inventionFirst or secondIn the constitution, the binder resin is characterized in that a jojoba oil derivative derivative is added to the binder resin solution and the solvent is removed as a main component.
[0059]
  Furthermore, the present inventionFirst or secondIn the configuration, the external additive has an average particle size of 0.02 to 4 μm, and a BET specific surface area of 0.1 to 100 m by nitrogen adsorption.²It comprises a metal salt-based fine powder comprising at least one of titanate-based fine powder or zirconiaate-based fine powder which is / g.
  Furthermore, the present invention is characterized in that, in the first or second configuration, the metal salt fine powder is prepared by a hydrothermal method or an oxalate pyrolysis method.
[0061]
  Furthermore, the present inventionFirst or secondIn the configuration, the external additive has an average particle size of 0.02 to 2 μm, and a BET specific surface area of 0.1 to 100 m by nitrogen adsorption.²/ G, electrical resistivity is 10⁹Metal oxide comprising at least one of titanium oxide fine powder, aluminum oxide fine powder, strontium oxide fine powder, tin oxide fine powder, zirconia fine powder, magnesium oxide fine powder, and indium oxide fine powder that are Ωcm or less It contains fine powder.
[0063]
  Furthermore, the present inventionFirst or secondIn the configuration, the external additive has a BET specific surface area of 1 to 200 m by nitrogen adsorption.²Metal oxide fine powder comprising titanium oxide and / or silica oxide fine powder surface-treated with a / g tin oxide-antimony mixture.
[0064]
  Furthermore, the present inventionFirst or secondIn the constitution, the external additive has an average particle diameter of 0.02 to 2.0 μm and a ratio D25 / D75 of 25% residual diameter D25 to 75% residual diameter D75 is in the range of 1.3 to 1.7. , BET specific surface area by nitrogen adsorption is 0.5-80m²/ G and an electrical resistance of 10²-10¹¹Ωcm, bulk density of 0.3 to 0.9 g / cc, compression rate of 30 to 80%, linseed oil absorption of 10 to 30 (ml / 100 g), and residual magnetization of 5 to 20 emu / g, including magnetic fine powder having a saturation magnetization of 40 to 80 emu / g.
[0068]
DETAILED DESCRIPTION OF THE INVENTION
In this embodiment, an external additive is externally added to a toner base in which a colorant and a jojoba oil derivative are added to a binder resin. The jojoba oil derivative has a chemical effect that is different from that of polyethylene wax and polypropylene wax that have been generally used so far, and has a unique and excellent effect.
[0069]
Jojoba oil is a wax wax based on unsaturated higher fatty acids and alcohol extracted from jojoba fruit. The carbon number is mostly C40 and C42. The coarse wax obtained by pressing is liquid and becomes colorless and transparent when purified. Jojoba oil derivative is a derivative substance obtained based on this jojoba oil.
[0070]
Its main function is to improve the fixability as a fixing aid, strengthen the adhesion to paper, reduce the frictional resistance on the image surface on the paper, and suppress the toner peeling from the paper due to scratching, thereby fixing the paper The effect which improves is acquired. Further, in a color toner in which a sharp melt resin is almost completely melted, the effect of improving the offset resistance is great.
[0071]
Good compatibility with styrene acrylic resin and polyester resin, which will be described later, high dispersibility, generation of fog on non-image areas, image loss at the back edge of solid black image areas, and photoconductors Prevent filming. Further, the loss on heating is small, and when applied to a color toner, it becomes a sharp melt. Furthermore, the charging characteristics under high temperature and high humidity and low temperature and low humidity are stable, and it is a suitable material for toner. Further, in a situation where the electrophotographic process is different, materials corresponding to the process can be provided by the configuration of various derivatives. For example, when used under high stress at high speed, the effect of preventing the durability from being lowered can be obtained by employing a fatty acid metal salt. In addition, when a sharp melt binder resin requires more offset resistance, an isocyanate polymer or an amide derivative is preferably used. When used as a negatively chargeable toner, a maleic acid derivative or a fatty acid can be used effectively.
[0072]
Jojoba oil derivatives include jojoba oil fatty acid, metal salt of jojoba oil fatty acid, jojoba oil fatty acid ester, hydrogenated jojoba oil, jojoba oil amide, homo jojoba oil amide, jojoba oil triester, maleic acid derivative of epoxidized jojoba oil, jojoba An isocyanate polymer of oil fatty acid polyhydric alcohol ester and halogenated modified jojoba oil are preferable materials. These can be used alone or in combination of two or more.
[0073]
Jojoba oil fatty acid obtained by saponifying and decomposing jojoba oil consists of fatty acids having 18 to 22 carbon atoms. As the metal salt, metal salts such as sodium, potassium, calcium, magnesium, barium, zinc, lead, manganese, iron, nickel, cobalt, and aluminum can be used.
[0074]
Examples of jojoba oil fatty acid esters include methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, trimethylolpropane and the like, and in particular, jojoba oil fatty acid pentaerythritol monoester, jojoba oil fatty acid pentaerythritol triester, jojoba Oil fatty acid trimethylolpropane ester and the like are preferable.
[0075]
Furthermore, an esterification reaction product of jojoba oil fatty acid and a polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane, tolylene diisocyanate (TDI), diphenylmethane-4,4′-disicocyanate (MDI), etc. An isocyanate polymer of jojoba oil fatty acid polyhydric alcohol ester obtained by crosslinking with the above isocyanate can also be preferably used.
[0076]
Hydrogenated jojoba oil is obtained by hydrogenating jojoba oil to make unsaturated bonds saturated bonds.
[0077]
Jojoba oil amide is obtained by hydrolyzing jojoba oil and then esterifying it into fatty acid methyl ester, and then reacting with a mixture of concentrated aqueous ammonia and ammonium chloride. Furthermore, it becomes possible to adjust melting | fusing point by hydrogenating this. It is also possible to hydrogenate before hydrolysis. A product having a melting point of 75 to 120 ° C. is obtained. Homo jojoba oil amide is obtained through hydrolysis of jojoba oil and then reducing it to alcohol, followed by nitrile.
[0078]
(Formula 4) shows the process of forming jojoba oil amide.
[0079]
[Formula 4]

[0080]
(Formula 5) shows the process of forming homojojoba oil amide.
[0081]
[Chemical formula 5]

[0082]
The jojoba oil triester is obtained by epoxidizing jojoba oil, acylating with organic acid and fatty acid after hydration and ring opening. (Generation 6) shows the generation process.
[0083]
[Chemical 6]

[0084]
The addition amount is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the toner. If the amount is less than 0.1 parts by weight, the effect of fixability and offset resistance cannot be obtained. If the amount is more than 20 parts by weight, storage stability is deteriorated and problems arise in grindability such as overgrinding. The melting point is preferably in the range of 40 to 130 ° C, more preferably 45 to 120 ° C, still more preferably 50 to 110 ° C. When the temperature is lower than 40 ° C., the storage stability is deteriorated. Moreover, in the molecular weight in GPC, Mn is 100-5000, Mw is 200-10000, Mw / Mn is 8 or less, and Mz / Mn is 10 or less. More preferably, Mn is 100 to 5000, Mw is 200 to 10,000, Mw / Mn is 7 or less, Mz / Mn is 9 or less, more preferably Mn is 100 to 5000, Mw is 200 to 10,000, and Mw / Mn is 6 or less. , Mz / Mn is 8 or less. When Mn is smaller than 100 and Mw is smaller than 200, the storage stability is deteriorated. When Mn is larger than 5000, Mw is larger than 10,000, Mw / Mn is larger than 8, and Mz / Mn is larger than 10, fixing functions such as fixing property and offset resistance are deteriorated.
[0085]
It can be used in combination with other components. For example, plant waxes such as caluna wax, candelilla wax, lanolin, beeswax, beeswax, ozokerite, ceresin, rice wax, polyolefin wax such as polyethylene, polypropylene, fatty acid amide, stearic acid, palmitic acid, lauric acid, Higher fatty acids such as aluminum stearate, barium stearate, zinc stearate, zinc palmitate, etc., or derivatives thereof such as metal products and esters thereof can be used alone or in combination.
[0086]
Binder resins that are preferably used include homopolymers or copolymers of various vinyl monomers. For example, styrene, O-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn butyl styrene, p-tert-butyl styrene, pn-hexyl Styrene and its derivatives such as styrene, pn-octyl styrene, pn-hexyl styrene, P-chlorostyrene, and the like are exemplified, and styrene is particularly preferable.
[0087]
As the acrylic monomer, in the formula of the general formula (Formula 1), R1 is a hydrogen atom or a lower alkyl group, R2 is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms, a hydroxylalkyl group, a vinyl ester group or An aminoacryl group. Examples of the acrylic monomer include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid-2-ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, methacrylic acid. Acid 2-ethylhexyl, β-hydroxyethyl acrylate, γ-hydroxyacrylate propyl α-hydroxyacrylate butyl, β-hydroxyethyl methacrylate, γ-aminoacrylate propyl, γ-N, N-diethylaminoacrylate propyl , Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and the like. A preferred styrene-acrylic copolymer is a styrene / butyl acrylate copolymer, and particularly, one containing 75 to 85% by weight of styrene and 15 to 25% by weight of butyl acrylate is preferably used.
[0088]
More preferably used as the binder resin is a (meth) acrylic acid monomer having a long chain alkyl group represented by the above chemical formula (Chemical Formula 2) together with a styrene-based (meth) acrylic acid monomer. Some are copolymerized. As a result, the dispersibility of the jojoba oil derivative is remarkably improved, and the occurrence of fogging in the non-image area, the lack of the image in the solid black image area rear end, and the occurrence of filming on the photoreceptor are prevented. In addition, the fixability and offset resistance are improved, the stability of charging, the increase in charge under high temperature and low humidity, and the constant mixing ratio of carrier and toner under high humidity in the case of two-component development method. This has the effect of suppressing environmental problems such as poor toner density control. 0.01 to 8 parts by weight is added to 100 parts by weight of the binder resin. If the amount is too small, the effect cannot be obtained. If the amount is too large, the durability of the resin decreases.
[0089]
Further, as the binder resin, a copolymer obtained by copolymerizing a (meth) acrylic acid-based monomer having an amino group represented by the chemical formula (Chemical Formula 3) together with a styrene-based (meth) acrylic acid-based monomer. Preferably used. For example, it is a vinyl monomer having an amino group such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dibutylaminoethyl (meth) acrylate and the like. This suppresses overcharging of the toner containing the jojoba oil derivative under high temperature and low humidity, stabilizes charging, and provides image quality stability. This is effective not only for positively charged toner but also for negatively charged toner. 0.01 to 5 parts by weight is added to 100 parts by weight of the binder resin. If the amount is too small, the effect cannot be obtained. If the amount is too large, the moisture resistance decreases.
[0090]
As a method for producing the polymer, known polymerization methods such as bulk polymerization, bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. A method of carrying out bulk polymerization to a polymerization rate of 30 to 90% by weight and then adding a solvent and a polymerization initiator and continuing the reaction by solution polymerization is also preferred.
[0091]
In order to make the toner compatible with a wide range of development process speeds (for example, 140 mm / sec to 480 mm / sec), only improvement in toner fixing property and charging property by improving the dispersibility of the additive during the kneading. In addition, it is necessary to further increase the penetrating power to the paper by heat melting of the binder resin and to have an appropriate viscoelasticity in order to improve the offset resistance. In order to increase the penetrating power to paper and improve the offset resistance, it is preferable to specify the composition, glass transition point, and molecular weight of each of the low molecular weight polymer component and the high molecular weight polymer component of the binder resin.
[0092]
The binder resin as a whole has a weight average molecular weight Mw of 100,000 to 600,000, a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 50 to 100, and a ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn. It is preferable that the 1/2 outflow temperature (henceforth softening point) by 350-1200 and a Koka flow tester is 100-145 degreeC.
[0093]
Furthermore, the weight average molecular weight Mw is 120,000 to 450,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 60 to 95, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 500 to 1100. The softening point is more preferably 105 to 135 ° C. Furthermore, the weight average molecular weight Mw is 150,000 to 450,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 70 to 95, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 600 to 1100. The softening point is more preferably 110 to 135 ° C. In order to further improve the fixability and pulverizability during pulverization in the production stage, the binder resin preferably contains 50 to 95% by weight of a styrene component. Further, the outflow start temperature of the binder resin by the flow tester is in the range of 80 to 120 ° C, preferably in the range of 85 to 110 ° C, more preferably in the range of 85 to 100 ° C.
[0094]
When Mw is less than 100,000, Mw / Mn is less than 50, the ratio Mz / Mn is less than 350, the softening point is less than 100 ° C, and the outflow start temperature is less than 80 ° C, the shear force during kneading Is difficult to dissipate, and the dispersibility of the jojoba oil derivative is lowered, and the offset resistance at low speed is deteriorated. When Mw is greater than 600,000, Mw / Mn is greater than 100, the ratio Mz / Mn is greater than 1200, the softening point is greater than 145 ° C, and the outflow start temperature is greater than 120 ° C, the fixability at high speed is It deteriorates and the grindability deteriorates.
[0095]
The Z average molecular weight best represents the magnitude and amount of the molecular weight in the tailing portion on the high molecular weight side, and has a great influence on the toner characteristics to which the jojoba oil derivative is added. The greater the Mz, the greater the resin strength, the viscosity during hot melt kneading, and the dispersibility is significantly improved. In addition to suppressing fogging and toner scattering, it is possible to obtain an effect of suppressing environmental fluctuations under high temperature and low humidity and high humidity. Increasing Mz / Mn broadly extends to the ultra-high molecular weight region, and the meltability during kneading is good and the melt viscosity is increased.
[0096]
The molecular weight is a value measured by gel permeation chromatography using several types of monodisperse polystyrene as a standard sample. That is, it is a value measured by flowing tetrahydrofuran at a flow rate of 1 ml / min at a temperature of 25 ° C. and injecting 10 mg of a tetrahydrofuran sample solution having a concentration of 0.5 g / dl by weight into the sample. The measurement conditions are conditions in which the molecular weight distribution of the target sample is included in a range in which the logarithm of the molecular weight and the count number are linear in a calibration curve obtained with several types of monodisperse polystyrene standard samples.
[0097]
The softening point of the binder resin is 1 cm by a flow tester (CFT500) manufactured by Shimadzu Corporation.^Three 20 kg / cm with a plunger while heating the sample at a heating rate of 6 ° C./min² When the height of the characteristic line is h from the relationship between the plunger drop and the temperature rise temperature characteristic, the temperature relative to h / 2 is set to the softening point ( Tm), the temperature at the start of outflow at the time of extrusion was defined as the outflow start temperature (Ti).
[0098]
For the melting point of the endothermic peak by DSC method, a differential calorimeter DSC-50 manufactured by Shimadzu Corporation was used. The temperature was raised to 200 ° C. at 5 ° C./min, rapidly cooled to 10 ° C. for 5 minutes, allowed to stand for 15 minutes, then heated at 5 ° C./min, and determined from the endothermic (melting) peak. The amount of sample put into the cell was 10 mg + -2 mg.
[0099]
In the toner of this embodiment, a jojoba oil derivative may be added in advance to the binder resin. Usually, the jojoba oil derivative is mixed at the same time as the binder resin, the colorant, the charge control agent, etc. in the preliminary mixing step, but in order to mix uniformly, a certain amount of stirring force is required, which is inevitably mixed. The temperature inside the machine tank rises. For this reason, the jojoba oil derivative having a low melting point causes aggregation and poor dispersion. Therefore, this problem can be solved by dispersing in the binder resin. That is, a binder resin is dissolved in the following solvent to prepare a binder resin solution and mixed with the jojoba oil derivative, and then the binder resin solution is desolvated at 120 to 250 ° C. under normal pressure or reduced pressure. It is a process. It is preferable to carry out at 150-220 degreeC from a viewpoint of prevention of the thermal deterioration of binder resin or jojoba oil derivative, and the efficiency of solvent removal. By adding the jojoba oil derivative to the binder resin solution and removing the solvent, phase separation between the binder resin and the jojoba oil derivative is suppressed and the compatibility is improved, and the jojoba oil generated in the preliminary mixing step The dispersibility of the derivative is improved and the dispersibility of the colorant and other internal additives is also improved. Further, the heating loss of the jojoba oil derivative at 220 ° C. is preferably 8% by weight or less. When the loss on heating is greater than 8% by weight, the solvent is not sufficiently removed in the solvent removal step of the binder resin solution, and remains in the binder resin. For this reason, the glass transition point of the binder resin is greatly reduced, and the storage stability of the toner is impaired. The total amount of addition to the binder resin may be carried out, or a part may be added and mixed during mixing. 0.1-10 weight part is preferable with respect to 100 weight part of binder resin. If it is less than 0.1, it is difficult to obtain the effect of improving dispersibility. If it is larger than 10, the efficiency of solvent removal is lowered and the productivity is deteriorated.
[0100]
Solvents are hydrocarbon solvents such as benzene, triol, xylol, cyclohexane, solvent naphtha, methanol, ethanol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, iso-butyl alcohol, amyl alcohol, cyclohexanol. Alcohol solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketone solvents, ethyl acetate, n-butyl acetate, cellosolve acetate and other ester solvents, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methylcarbitol And ether solvents such as
[0101]
As the binder resin, a polyester resin obtained by polycondensation of a polyvalent carboxylic acid or a lower alkyl ester thereof and a polyhydric alcohol is preferably used. Examples of the polyvalent carboxylic acid or lower alkyl ester include aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, hexahydrophthalic anhydride, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid And aliphatic unsaturated dibasic acids such as phthalic anhydride, phthalic anhydride, terephthalic acid and isophthalic acid, and methyl and ethyl esters thereof. Of these, aromatic dibasic acids such as phthalic acid, terephthalic acid and isophthalic acid, and lower alkyl esters thereof are preferred.
[0102]
Examples of the polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, Examples include diols such as dipropylene glycol, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct, triols such as glycerin, trimethylolpropane, and trimethylolethane, and mixtures thereof. Among these, neopentyl glycol, totimethylolpropane, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct are preferable.
[0103]
For the polymerization, known polycondensation, solution polycondensation or the like can be used. As a result, a good toner can be obtained without impairing the PVC mat resistance and the color of the color toner.
[0104]
The ratio of the polyvalent carboxylic acid and the polyhydric alcohol is generally 0.8 to 1.4 in terms of the ratio of the number of hydroxyl groups to the number of carboxyl groups (OH / COOH).
[0105]
The acid value of the polyester resin is preferably 1 to 100. If it is less than 1, the dispersibility of the jojoba oil derivative decreases. If it exceeds 100, the moisture resistance decreases.
[0106]
This polyester resin has a weight average molecular weight Mw of 10,000 to 300,000, a ratio Mw / Mn of weight average molecular weight Mw to number average molecular weight Mn of 3 to 50, and a ratio Mz / Mn of Z average molecular weight Mz to number average molecular weight Mn. It is preferable that the efflux temperature is 10 to 800, the ½ outflow temperature (hereinafter referred to as softening point) is 80 to 150 ° C, and the outflow start temperature is 80 to 120 ° C.
[0107]
In a toner for color process in which an image having four colors is formed and fixed, from the viewpoint of translucency and gloss, the weight average molecular weight Mw is 10,000 to 180,000, and the ratio Mw / weight average molecular weight Mw to number average molecular weight Mn It is preferable that Mn is 3 to 20, the ratio Mz / Mn of Z average molecular weight Mz to number average molecular weight Mn is 10 to 300, the softening point is 85 to 120 ° C, and the outflow start temperature is 80 to 110 ° C. More preferably, the weight average molecular weight Mw is 10,000 to 150,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 3 to 16, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 10 ˜260, softening point is preferably 90 to 115 ° C., and the outflow start temperature is preferably in the range of 85 to 110 ° C. More preferably, the weight average molecular weight Mw is 10,000 to 100,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 5 to 12, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 14 ˜220, softening point is 95˜115 ° C., outflow start temperature is preferably 85˜105 ° C.
[0108]
In black toner for black-and-white process that is one-color development, it is not necessary to consider light transmission and smoothness, but it is necessary to cope with a wide range of development process speeds (for example, 140 mm / sec to 480 mm / sec). In some cases, not only the toner fixability and chargeability are improved by improving the dispersibility of the additive during the kneading, but also the paper penetration by heat melting of the binder resin is further increased, and In order to improve the offset resistance, it is necessary to have an appropriate viscoelasticity. Therefore, the weight average molecular weight Mw is 50,000 to 300,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 5 to 50, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 50 to 800. The softening point is preferably in the range of 90 to 150 ° C and the outflow start temperature is in the range of 80 to 120 ° C. More preferably, the weight average molecular weight Mw is 80,000 to 250,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 7 to 45, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 100. -700, softening point is preferably in the range of 95-146 ° C, and the outflow start temperature is preferably in the range of 85-115 ° C. More preferably, the weight average molecular weight Mw is 100,000 to 220,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 9 to 45, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 150. ˜600, softening point is preferably 100 to 142 ° C., and outflow start temperature is preferably in the range of 85 to 110 ° C.
[0109]
Moreover, the BET specific surface area by nitrogen adsorption is 30-350m.²/ G of hydrophobic silica is externally added to the toner base. The silica used is a so-called dry process or fumed silica produced by vapor phase oxidation of a silicon halide. Silanol groups present on the surface are treated and coated with a silane coupling agent or silicone oil to improve moisture resistance.
[0110]
As the silica used, silica treated with at least one of dimethyl silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, and epoxy-modified silicone oil is preferably used. The For example, SH200, SH510, SF230, SH203, BY16-823, BY16-855B, etc. manufactured by Toray Dow Corning Silicone may be mentioned.
[0111]
In addition, dimethylsilicone oil having silanols at both ends further improves the reactivity, reduces the residual amount of unreacted polydimethylsiloxane, and reduces filming on the photoreceptor.
[0112]
Silica treated with these silicone oils has suitable contact adhesion with the jojoba oil derivative added to the toner base, is uniformly adhered and mixed on the toner surface, is less detached, and waste toner is recycled. However, stable fluidity can be obtained.
[0113]
Treatment is a method of mixing fine powder and silicone oil with a mixer such as a Henschel mixer, a method of spraying silicone oil onto silica, after dissolving or dispersing silicone oil in a solvent, and then mixing with silica fine powder, There is a method of removing the solvent and making it.
[0114]
Moreover, it is also preferable to perform a silicone oil treatment after the silane coupling treatment. As silane coupling agents, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzylmethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, There are vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, and the like. The silane coupling agent treatment is a dry treatment in which the vaporized silane coupling agent is reacted with a fine powder made into a cloud by stirring or the like, or a wet treatment in which a silane coupling agent in which the fine powder is dispersed in a solvent is dropped. Processed by law.
[0115]
A more preferable specific surface area is 50 to 300 m.²/ G, more preferably 80 to 250 m²/ G is preferable. The hydrophobic silica is generally added in an amount of 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, per 100 parts by weight of the toner base particles. Specific surface area is 30m²When it is less than / g, the fluidity of the toner is not improved and the storage stability is lowered. Specific surface area is 350m²When it exceeds / g, the aggregation of silica deteriorates, and the fixing function of the jojoba oil derivative is suppressed.
[0116]
Further, the toner of the present embodiment is configured to perform surface modification treatment with hot air. As a result, the fluidity and developability of the toner to which the jojoba oil derivative is added are stabilized, and the durability and recyclability are improved. In particular, a toner to which a jojoba oil derivative is added is exposed to the surface of the toner by heat from hot air, and fixing characteristics such as fixing property and offset resistance are improved.
[0117]
In addition, a configuration in which one or more of hydrophobic silica, metal oxide fine powder, and metal acid salt fine powder are externally added and added to the toner base and then subjected to surface modification treatment with hot air also exhibits good characteristics. Furthermore, even if one or more of hydrophobic silica, metal oxide fine powder and metal acid salt fine powder are externally added and mixed after the surface modification treatment, better characteristics are exhibited.
[0118]
Not only the toner base is spheroidized by the surface modification treatment, but by fixing these external additives, separation from the toner base can be prevented, and waste toner recyclability is improved.
[0119]
Furthermore, a part of the jojoba oil derivative added to the toner by heat is exposed on the surface of the toner base, so that the fixing characteristics are improved. However, overcharging under high temperature and low humidity is likely to occur, and waste toner is recycled. At this time, adhesion to the cleaning blade is slightly likely to occur. In addition, in the two-component development system that detects the magnetic fluctuation (change in magnetic permeability) of the developer and makes the concentration ratio of the carrier and the toner constant, for example, a magnetic permeability sensor is used, but under high humidity After being left for a long time, the toner density control becomes inoperable, and an over-toner phenomenon in which the toner is excessively replenished tends to increase fog and scattering.
[0120]
However, the structure that stabilizes the fluidity, and the hydrophobic silica, etc., are fixedly attached to the surface of the toner base to alleviate the packing phenomenon when left under high humidity, and under high temperature, low humidity, and high humidity. It is possible to suppress the operation failure and stabilize the charging.
[0121]
This will be described with reference to the drawings. FIG. 1 is a schematic view of a surface modification apparatus using hot air. A predetermined particle size distribution is obtained by pulverization and classification, and the toner particles 101 are fed from a fixed amount supply machine 102 and sent by a compressed air 103 to a dispersion nozzle 104 which is a particle dispersion means, and are ejected in a direction of about 45 degrees. . Two dispersion nozzles 104 are arranged at symmetrical positions. This is because the toner can be more uniformly processed by being ejected from a plurality of nozzles. In order to radiate hot air to the toner 101 ejected from the dispersion nozzle 104, hot air 106 is radiated from the hot air generator 105. A heater is used as the hot air generator 105. Any device can be used as long as it can generate hot air, and the device heated by propane gas or the like is not limited. The toner 101 passes through the hot air 106 while being dispersed, and is subjected to surface modification treatment. The surface-modified toner is taken into the hood 107, sent to the cyclone 110, and collected and collected in the collection box 111. 112 is a bag filter, 114 is a blower, 113 is an air flow meter, and 115 is a thermometer.
[0122]
In addition, it is possible to subject the surface-modified particles that have been taken into the hood 107 to a cooling process by the cooling air 109 generated from the cooling air generator 108. This rapid cooling stabilizes the processing state. The air volume is appropriately determined depending on the processing volume. The distance from the position where the particles are treated with hot air to the point where the cooling air is applied is determined by the amount of treatment, but is 10 to 100 cm, preferably 20 to 80 cm. The cooling process is preferably a method using air cooled to 10 ° C. or less by a cooler, but is not limited. There are a method of water cooling, a method of disposing a cooled solid material around a pipe, such as dry ice.
[0123]
When the above method is used, the production efficiency is improved because of the continuous method.
Further, since the surface modification is performed in a dispersed state, the particles are not fused with each other and coarse particles are not generated. It is compact with a very simple configuration. There is no increase in the wall temperature and the product recovery rate is high. Since the treatment is performed instantaneously with hot air, the entire carrier particles are uniformly treated without aggregation between the particles. The hot air temperature for the treatment at this time is preferably 60 ° C to 600 ° C. Preferably it is 100 to 500 degreeC, More preferably, it is 150 to 350 degreeC. When the temperature is lower than 60 ° C., the effect of the surface modification treatment cannot be obtained. When the temperature is higher than 600 ° C., aggregation of toner base particles tends to occur, which is inappropriate. Hot air flow rate is 3-5kg / cm²0.35 to 1.0 Nm for G^Three/ Min, raw material supply dispersion air volume is 1 to 3 kg / cm²0.05 to 0.5 Nm for G^Three/ Min is a suitable range. The ratio of the hot air flow rate to the raw material supply dispersed air flow rate is preferably in the range of 10: 1 to 4: 1. If the amount of hot air is too large, the raw material will be repelled and uniform processing will not be possible. If the amount of raw material supply and dispersion is too large, the raw material will cross the hot air and cannot be uniformly processed.
[0124]
In this heat treatment, hydrophobic silica may be externally attached to the toner base, and then heat treatment may be applied to fix the toner base. In particular, when the waste toner is recycled, the detachment of the external additive is suppressed, and the durability is further improved. As a result, the fixing property can be further improved, toner overcharging during long-term use can be prevented, and low fog and high image density in the non-image area can be maintained for a long time.
[0125]
The average particle size is 0.02 to 4 μm, and the BET specific surface area by nitrogen adsorption is 0.1 to 100 m.²/ G of titanate-based fine powder or zirconiaate-based fine powder containing at least one metal acid salt fine powder in the toner, so that good characteristics can be obtained in the toner added with jojoba oil derivative. Indicates. In particular, it is effective for stabilization of charging during recycling of waste toner, prevention of filming, and maintenance of charging during continuous use under low humidity.
[0126]
Materials include SrTiO3, BaTiO3, MgTiO3, AlTiO3, CaTiO3, PbTiO3, FeTiO3, SrZrO3, BaZrO3, MgZrO3, AlZrO3, CaZrO3, PbZrO3, SrSiO3, BaSiO3, MnSiO3, SiO, MnSiO3, SiO.
[0127]
Moreover, the effect is further enhanced by producing these metal salt fine powders by a hydrothermal method or an oxalate pyrolysis method. This is because the generated material has a uniform particle size distribution and the shape is more spherical than the indefinite shape. Average particle size is smaller than 0.02μm, BET specific surface area by nitrogen adsorption is 100m²If it exceeds / g, the particles are strongly aggregated and the dispersibility is lowered. Average particle size is larger than 4μm, BET specific surface area by nitrogen adsorption is 0.1m²If it is less than / g, damage to the photoreceptor due to the particles increases.
[0128]
Fine powder synthesis under hydrothermal conditions includes hydrothermal oxidation, hydrothermal precipitation, hydrothermal synthesis, hydrothermal dispersion, hydrothermal crystallization, hydrothermal hydrolysis, hydrothermal attritor. There are a mixing method and a hydrothermal mechanochemical method. Preferred are hydrothermal oxidation method, hydrothermal precipitation method, hydrothermal synthesis method, hydrothermal dispersion method, and hydrothermal hydrolysis method.
[0129]
The fine powder synthesized by this method provides a spherical fine powder with little aggregation, a narrow particle size distribution, and good fluidity. Therefore, when the toner is externally mixed, the dispersibility is good and the toner adheres uniformly. Since the shape is spherical, the photoconductor is not damaged unnecessarily.
[0130]
Furthermore, the average particle size is 0.02 to 2 μm, the BET specific surface area by nitrogen adsorption is 0.1 to 100 m.²/ G, electrical resistivity is 10⁹Metal oxide comprising at least one of titanium oxide fine powder, aluminum oxide fine powder, strontium oxide fine powder, tin oxide fine powder, zirconia fine powder, magnesium oxide fine powder, and indium oxide fine powder that are Ωcm or less By containing a fine powder, it is suitably used for a toner to which a jojoba oil derivative is added.
[0131]
More preferably, the average particle size is 0.02 to 0.8 μm, and the BET specific surface area by nitrogen adsorption is 1.0 to 85 m.²/ G, more preferably, an average particle size of 0.02 to 0.1 μm, a BET specific surface area by nitrogen adsorption of 8 to 85 m 2 / g, even more preferably, an average particle size of 0.02 to 0.06 μm, by nitrogen adsorption BET specific surface area of 10-85m²/ G.
[0132]
The toner containing the jojoba oil derivative is effective for stabilizing the charging property at high temperature and low humidity, further transferability, and waste toner recyclability. Further, the toner density control when used in two-component development is stabilized, and the effect is obtained particularly under high temperature and low humidity.
[0133]
Average particle size is smaller than 0.02μm, BET specific surface area by nitrogen adsorption is 100m²If it exceeds / g, the cohesion is strong and uniform dispersion during the external addition treatment cannot be performed. Electrical resistivity is 10⁹When it becomes larger than Ωcm, the above effect is lowered. Average particle size is larger than 2μm, BET specific surface area by nitrogen adsorption is 0.1m²If it is less than / g, the toner is severely detached from the toner base, affecting the durability and increasing the damage to the photoreceptor.
[0134]
Furthermore, a BET specific surface area of 1 to 200 m by nitrogen adsorption.²It is preferably used for a toner to which a jojoba oil derivative is added by containing metal oxide fine powder comprising titanium oxide and / or silica oxide fine powder surface-treated with a / g tin oxide-antimony mixture. The 200m²If it is larger than / g, the mixing process cannot be performed uniformly, and 1 m²If it is less than / g, desorption from the toner increases and the durability of the toner decreases.
[0135]
Furthermore, the average particle size is 0.02 to 2.0 μm, and the ratio D25 / D75 of 25% residual diameter D25 to 75% residual diameter D75 is in the range of 1.3 to 1.7, and BET due to nitrogen adsorption. Specific surface area is 0.5-80m²/ G and an electrical resistance of 10²-10¹¹Ωcm, bulk density of 0.3 to 0.9 g / cc, compression rate of 30 to 80%, linseed oil absorption of 10 to 30 (ml / 100 g), and residual magnetization of 5 to 20 emu / g. By containing a metal oxide fine powder composed of a magnetic fine powder having a saturation magnetization of 40 to 80 emu / g, it is suitably used for a toner to which a jojoba oil derivative is added.
[0136]
As the magnetic fine powder, a metal, an alloy or a compound containing these metals showing a ferromagnetic material such as iron, cobalt, nickel, manganese, and magnetite is preferably used. The shape of the magnetic fine powder is preferably spherical or octahedral. The average particle size of the magnetic fine powder is preferably 0.02 to 2.0 μm and D25 / D75 is preferably 1.3 to 1.7. Preferably the average particle size is 0.05 to 1.0 μm and the ratio D25 / D75 is 1.3 to 1.6, more preferably the average particle size is 0.05 to 0.5 μm and the ratio D25 / D75 is 1.3. ~ 1.5.
[0137]
When the particle size of the magnetic fine powder is smaller than 0.02 μm or the ratio D25 / D75 is smaller than 1.3, the proportion of the small particle size is high and the cohesion is strong, and the dispersibility at the time of mixing is not improved. The effect of addition cannot be demonstrated. When the particle diameter of the magnetic fine powder is larger than 2.0 μm or the ratio D25 / D75 is larger than 1.7, the ratio of the large particle diameter is not high, and the width of the particle size distribution is widened. And the ratio of small particle size particles both increase, resulting in poor image quality, making it difficult to uniformly adhere to the surface of the toner base, and increasing scratches on the photoreceptor. Photographs were taken with a scanning electron microscope, 100 particles were randomly selected, and the particle size was measured.
[0138]
BET specific surface area due to nitrogen adsorption of magnetic fine powder is 0.5-80m²/ G is preferable. More preferably 2-60m²/ G, more preferably 10-60 m²/ G, more preferably 18-60 m²Those in the / g range are more preferred. 0.5m²If it is less than / g, the contact ratio with the toner base decreases, so that it is difficult to obtain the effect of adding magnetic particles. 80m²When it exceeds / g, the aggregation of the particles becomes strong and the dispersion during mixing becomes non-uniform, so that it is difficult to obtain the effects on the developing property and the stability of controlling the toner concentration. The BET specific surface area was measured using FlowSorbII2300 manufactured by Shimadzu Corporation.
[0139]
The resistance of fine magnetic powder is 10²-10¹¹Those of Ωcm are preferable. Preferably 10^Five-10^TenΩcm, more preferably 10⁶-10⁹Those of Ωcm are preferable. In the case of low resistance powder, the amount of charge is greatly reduced under high humidity, and fog toner scattering increases. When the resistance is high, the effect of suppressing overcharging under high temperature and low humidity is weakened.
[0140]
The volume resistivity is measured by placing 1 ml of magnetic particle material in a cylindrical container whose bottom surface is made of an electrode having an inner diameter of 20 mm and whose side wall is made of an insulating material, and then having a diameter of less than 20 mm and a weight of 100 g on the test material. The electrode plate was placed and allowed to stand for 1 hour, and then a DC voltage of 100 V was applied between both electrodes, and the current value 1 minute after application was measured and calculated.
[0141]
The bulk density of the magnetic fine powder is preferably 0.3 to 0.9 g / cc, and the compression rate is preferably 30 to 80%. More preferably, the bulk density is 0.4 to 0.9 g / cc, and the compression rate is 40 to 70%. More preferably, the bulk density is 0.5 to 0.9 g / cc, and the compression rate is 45 to 65%. If the bulk density is greater than 0.9 g / cc and the compression ratio is less than 30%, the developer density tends to clog when left under high humidity, and the toner density control under high humidity is unstable. And run over toner. When the bulk density is less than 0.3 g / cc and the compression ratio is more than 80%, the aggregation of the particles becomes large, resulting in hindering uniform mixing, and the effect of suppressing overcharge at high temperature and low humidity is lost. Bulk density and compressibility were measured with a powder tester manufactured by Hosokawa Micron. The compressibility is the difference between the bulk density, which is the loose specific gravity, and the tap density divided by the tap density multiplied by 100. The fine magnetic powder is preferably crushed. It is preferably carried out by a mechanical pulverizer equipped with a high-speed rotor or a pressure disperser equipped with a pressure roller. It is preferable that the magnetic substance fine powder has a linseed oil absorption of 10 to 30 (ml / 100 g). The same effect as the above-described degree of compression and bulk density can be obtained. It is a value measured according to JIS K 5101-1978.
[0142]
Further, it is preferable that the remanent magnetization of the magnetic fine powder is 5 to 20 emu / g and the saturation magnetization is 40 to 80 emu / g under a magnetic field of 1 (kOe). It has been found that the addition of this fine powder is effective in reducing fog on the photoreceptor, particularly under high humidity. It is considered that the toner adhering to the photosensitive member as fog is changed into a spike of magnetic fine powder on the surface of the toner by addition of the magnetic substance, and is collected by the scraping effect thereby to reduce the fog.
[0143]
The surface of the magnetic fine powder added to the toner is surface-treated with a titanium coupling agent, a silane coupling agent, an epoxy silane coupling agent, an acrylic silane coupling agent, or an aminosilane coupling agent. For example, isopropyl triisostearoyl titanate, tetrabutoxy titanium, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) Titanate coupling agents such as oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) ) Silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxy Propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltri Silane coupling agents such as methoxysilane, γ-mercaptipropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, acrylic silane coupling agents such as γ-methacryloxypropyltrimethoxysilane, β-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane epoxy silane coupling agent, N-β aminoethyl γ-aminopropyltrimethoxysilane, N-β aminoethyl γ-aminopropylme Rujitokishishiran, .gamma.-aminopropyltriethoxysilane, an aminosilane coupling agent N- phenyl--γ- aminopropyltrimethoxysilane is processed surface. For example, it can be processed by a generally known method such as a dry process in which a vaporized silane coupling agent is reacted with a magnetic substance, or a wet process in which a magnetic substance is dispersed in a solvent and a silane coupling agent is dropped.
[0144]
The amount of the metal oxide fine powder and / or metal acid salt fine powder added to the toner is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner base. If it is less than 0.1, the function is not exhibited, and if it is 5 or more, the moisture resistance deteriorates.
[0145]
When used as a two-component developer, the carrier is preferably one in which a magnetic material is coated with a resin containing conductive fine powder. As the conductive fine powder used, metal powder, carbon black, conductive oxides such as titanium oxide and zinc oxide, and the surface of powders such as titanium oxide, zinc oxide, barium sulfate, aluminum borate and potassium titanate are oxidized. Examples include tin, carbon black, and metal-coated ones.^TenThose of Ω · cm or less are preferable.
[0146]
As a carrier core material, an average particle size of 20-100 μm, preferably 30-80 μm, more preferably 30-60 μm of metal powder such as magnetite, iron, manganese, cobalt, nickel, chromium, magnetite or alloys thereof, chromium oxide , Iron sesquioxide, iron tetroxide, Cu—Zn ferrite, Mn—Zn ferrite, Ba—Ni ferrite, Ni—Zn ferrite, Li—Zn ferrite, Mg—Mn ferrite, Mg—Zn—Cu ferrite, Mn ferrite, Examples thereof include Mn—Mg ferrite and Li—Mn ferrite. In particular, the volume resistivity is 10⁸-10¹⁴Mn ferrite, Mn—Mg ferrite, and Li—Mn ferrite are in the range of Ωcm, and are preferable materials from the viewpoint of environmental protection and the shape is closer to a sphere than Cu—Zn. When the average particle size is smaller than 20 μm, carrier adhesion increases. If it exceeds 100 μm, it becomes difficult to obtain high-definition image quality. Volume resistivity is 10⁸When it is smaller than Ωcm, carrier adhesion increases, and 10¹⁴If it exceeds Ωcm, the image density decreases due to the charge-up of the developer.
[0147]
In order to form a coating layer on the carrier core material, a known coating method, for example, a dipping method in which a powder that is a carrier core material is immersed in a coating layer forming solution, a coating forming solution is applied to the surface of the carrier core material. Spray method for spraying, fluidized bed method for spraying the coating layer forming solution in a state where the carrier core material is floated by flowing air, mixing the carrier core material and the coating layer forming solution in a kneader coater, and removing the solvent. For example, a kneader coater method may be used.
[0148]
The resin used as the carrier coating layer is a straight silicone resin composed of an organosiloxane bond and its alkyd-modified, epoxy-modified, urethane-modified products, fluororesin, styrene resin, acrylic resin, methacrylic resin, polyester resin. , Polyamide resins, epoxy resins, polyether resins, phenol resins and the like, and these can be used alone or in combination. It can also be used as a copolymer.
[0149]
For toners containing jojoba oil derivatives, a mixed coating layer of a silicone resin and an acrylic resin is effective. In particular, a mixed system of a straight silicone resin having only a C 1-4 alkyl group such as a methyl group such as a methyl group, a straight silicone resin containing a phenyl group in the side chain group, and a (meth) acrylic resin is preferable.
[0150]
The silicone resin is preferably a room temperature curable silicone resin. For example, KR271, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406, SH840 (manufactured by Tore Silicone) and the like can be mentioned. Acrylic resins are (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, dodecyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid alkyl ester polymer resins such as isobutyl acid and 2-ethylhexyl (meth) acrylate are preferred. Furthermore, by having a resin comprising a (meth) acrylic acid alkyl polymer having a long chain alkyl having 14 to 26 carbon atoms represented by (Chemical Formula 1) as a coating layer, the characteristics are further improved.
[0151]
In the toner of this embodiment, a transfer material is inserted between an image carrier and a conductive elastic roller, and a transfer bias voltage is applied to the conductive elastic roller so that the toner image on the image carrier is electrostatically charged. And preferably used in an electrophotographic apparatus including a toner transfer system for transferring to a transfer material. Since this toner transfer system is contact transfer, a mechanical force other than electric force acts on the transfer, and the reverse polarity toner adhering to the surface of the photoreceptor that should not be transferred is transferred or passed through. The toner adhering to the surface of the photoconductor when not in paper may contaminate the transfer roller surface and contaminate the back surface of the transfer paper. However, by adding hydrophobic silica, metal oxide fine powder, and metal acid salt fine powder to the toner base whose dispersibility has been improved by adding jojoba oil derivative, stabilization of charging property can be obtained, and surface modification treatment Thus, by fixing the toner surface, it is possible to prevent omission during transfer, and further, it is possible to prevent filming of the jojoba oil derivative caused by being released from the toner on the surface of the photoreceptor. In addition, filming of toner and free jojoba oil derivative on the transfer roller surface can be prevented, so image defects caused by retransfer of toner and free jojoba oil derivative from the transfer roller surface to the photoreceptor surface can also be prevented. Can do. Further, by using the toner in a low glass transition point toner, it is possible to cover a decrease in the durability of the toner, and at the same time, it is possible to achieve both storage stability, fixing property and high temperature offset property.
[0152]
The toner of this embodiment is suitably used in an electrophotographic apparatus including a waste toner recycling system that collects toner remaining on the image carrier after the transfer process in the developing device and uses it again in the developing process. Since waste toner is reused in development, it is subjected to mechanical shocks in the cleaning device, the transport pipe that connects the cleaning device and the developing device while being collected from the cleaning device to the developing device, and added to the developing device. The agent may fall off or filming may occur on the photoreceptor.
[0153]
However, by adding hydrophobic silica, metal oxide fine powder and metal acid salt fine powder to the toner base, which has improved dispersibility by adding jojoba oil derivative, stabilization of chargeability can be obtained, and surface modification treatment By fixing the toner on the surface of the toner, the chargeability can be stabilized even after continuous use for a long period of time. The external additive is injected into the jojoba oil derivative existing on the surface of the toner, so that the fluidity of the toner can be maintained over time. Change can be prevented. Furthermore, since the surface of the jojoba oil derivative is coated with an external additive, it can be prevented from falling off or filming on the photoreceptor. Further, since the change in the attached state of the external additive of the waste toner returned to the developing unit hardly occurs, the charge amount and the fluidity do not vary.
[0154]
Further, the toner of this embodiment is also suitably used as a magnetic one-component toner. In the electrophotographic apparatus according to this embodiment, an electrostatic latent image holding body containing a fixed magnet is used, and magnetic toner is sprinkled and magnetically attached to the electrostatic latent image holding body on which the electrostatic latent image is formed, thereby collecting the toner. It is assumed that the toner is carried and conveyed to the electrode roller, an AC bias is applied to the electrode roller, and the non-image area toner on the electrostatic latent image holding member is removed by electrostatic force and magnetic force. That is, the electrophotographic method of the present invention is a smaller and higher performance in the cascade development method in which a magnet is installed inside the electrostatic latent image holding member and an AC voltage is applied to the electrodes.
[0155]
By the way, since the structure of the developing process is simple, there are few opportunities for charging the toner, and it is difficult to obtain high charging characteristics. In addition, since toner adheres to the entire surface of the electrostatic latent image holding member during development, the toner film and the electrostatic latent image holding member are always in contact with each other as compared with the conventional one-component development method. This configuration is more likely to cause ming.
[0156]
However, by adding hydrophobic silica, metal oxide fine powder and metal acid salt fine powder to the toner base, which has improved dispersibility by adding jojoba oil derivative, stabilization of chargeability can be obtained, and surface modification treatment Thus, since the surface of the jojoba oil derivative is coated with an external additive by fixing the toner surface, filming on the photoreceptor can be prevented. In addition, the chargeability is stabilized even after continuous use for a long period of time, and the fluidity of the toner can be prevented from changing over time by driving an external additive into the jojoba oil derivative present on the toner surface. Thus, high chargeability can be obtained, high image density can be obtained, and a clear image can be obtained without scattering of toner around the characters.
[0157]
It is also suitably used for other magnetic one-component development methods. For example, a thin toner layer is formed on the developing sleeve using a rigid magnetic blade or an elastic rubber blade, and a toner image is formed by applying a direct current or an alternating current to the photosensitive member in contact or non-contact. It is suitably used for the developing method. Conventional toners using synthetic waxes such as polyethylene and polypropylene tend to cause filming on the photosensitive member, and there is no choice but to limit the number of sheets used. The filming phenomenon can be avoided and the service life of the photoreceptor can be increased.
[0158]
Specific examples of the magnetic substance added to the magnetic toner at this time include metal powders such as iron, manganese, nickel, and cobalt, and ferrites such as iron, manganese, nickel, cobalt, zinc, and magnetite. The magnetic material used as the fine metal oxide powder is preferably used.
[0159]
The addition amount is preferably 5 to 50% by weight, and if the addition amount is less than 5% by weight, the toner scattering tends to increase. If the addition amount is more than 50% by weight, the charge amount of the toner tends to decrease and the image quality tends to deteriorate. Become.
[0160]
In the toner of the present embodiment, the toner image formed on the surface of the image carrier is brought into contact with the surface of the endless intermediate transfer member on the surface of the image carrier and the toner image is transferred to the surface. A primary transfer process is repeatedly performed a plurality of times, and thereafter, a secondary transfer process is performed in which the overlapping transfer toner images formed on the surface of the intermediate transfer body are collectively transferred onto a transfer material by performing the primary transfer process a plurality of times. It is preferably used in an electrophotographic apparatus including a transfer system configured to be executed. Addition of jojoba oil derivative, surface modification treatment and immobilization treatment of hydrophobic silica on the toner surface can prevent voids at the time of transfer. Filming of the softening point material to the intermediate transfer member can be prevented, and contamination of the transfer paper with unnecessary toner particles can be prevented. Further, it is possible to prevent image defects caused by retransfer of the toner and the liberated softening point material from the transfer roller surface to the photoreceptor surface. Since the mutual adhesion between the toner particles is reduced and the toner aggregation is alleviated, the toner agglomeration effect can reduce the “collapse” phenomenon where a part of the image is not transferred but becomes a hole, and the transfer The effect which suppresses the fall of a rate is also acquired.
[0161]
Further, the toner of this embodiment includes a rotating photosensitive member and a developing unit having toners of different colors, and a plurality of movable image forming units that form toner images of different colors on the photosensitive member. The image forming unit group is arranged in a ring shape, and the entire image forming unit group is rotated and moved, and the toner images of different colors formed on the photosensitive member are transferred onto the transfer material in a superimposed manner and transferred to a color image. It is suitably used for a color electrophotographic apparatus for forming a film. Since the entire image forming unit rotates, a situation in which waste toner that has been cleaned from the photosensitive member and separated from the photosensitive member temporarily and repeatedly adheres to the photosensitive member always occurs. For this reason, if the low melting point synthetic wax is dispersed non-uniformly, there is a large amount of toner in which waste wax has unevenly distributed wax, and the waste toner repeatedly comes into contact with the photoreceptor again. As a result, filming on the image bearing member is remarkably likely to occur, which causes a reduction in the life of the photosensitive member. In addition, since the toner moves violently up and down as the image forming unit rotates, it is easy for toner to spill out from the seal portion. For this reason, it is necessary to reinforce the seal at the seal portion. In the toner in which the toner exists, a fusing phenomenon occurs, which becomes a lump and causes image noise of black and white stripes. In addition, a situation where the toner always detaches from the developing roller temporarily occurs, and if the rising property of charging is poor in the initial stage of development, it causes ground fogging. In the toner in which the unevenly distributed wax is present, the charge rising property tends to deteriorate.
[0162]
However, in the toner of this embodiment, the jojoba oil derivative is uniformly dispersed, so that the charge rising property is improved, the occurrence of filming on the photoreceptor is avoided, and the charge rising property is good. There is no occurrence of fog in the area.
[0163]
In addition, the toner of this embodiment is used for fixing a full-color image, and even in a fixed image in which four color toners are overlapped, the low-softening point polyester is used so that the toner is fixed in a form close to complete melting. Since the oil derivative is highly dispersed, good offset resistance can be obtained even in oil-free fixing without using oil, and a fixed image without color turbidity and loss of glossiness can be obtained.
[0164]
With the configuration described above, the jojoba oil derivative added to the binder resin acts as a fixing improver and has an effect of reducing friction on the image surface, and the apparent glass transition point of the toner is reduced. In addition, it exhibits a sufficient effect as a mold release agent, which enables both fixing strength at high speed and high-temperature offset resistance at low speed even when using a binder resin containing a large amount of high molecular weight components. In addition, satisfactory results can be obtained with high storage stability at high temperatures. Therefore, in a color image requiring translucency and glossiness, high-definition color reproducibility and a good release effect can be exhibited, so that the fixing device can be downsized.
[0165]
In addition, since high-viscosity resin can be used to prevent high-temperature offset of the low-speed machine and sufficient fixing strength can be secured in the high-speed machine, toner can be unified from the low-speed machine to the high-speed machine.
[0166]
In this embodiment, an appropriate pigment or dye is blended in the binder resin for the purpose of coloring the toner and / or controlling the charge. Such pigments or dyes include carbon black, iron black, graphite, nigrosine, metal complexes of azo dyes, salicylic acid metal salts, aniline blue, phthalocyanine blue, phthalocyanine blue, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow. Quinacridone, benzidine yellow, rose bengal, dupont oil red, triallylmethane dye, and the like, and one or more of these may be used in combination. An amount necessary for coloring and / or charge control is added to the binder resin.
[0167]
The toner is prepared through the steps of preliminary mixing, melt kneading, pulverization classification, and external addition treatment.
[0168]
The premixing process is a process in which the binder resin and the additive to be dispersed in the binder resin are uniformly dispersed by a mixer equipped with stirring blades. As the mixer, a known mixer such as a super mixer (manufactured by Kawada Seisakusho), a Henschel mixer (manufactured by Mitsui Miike Kogyo Co., Ltd.), a PS mixer (manufactured by Shinko Pantech Co., Ltd.) or a Ladige mixer is used.
[0169]
The melt-kneading process is a process of dispersing the additive in the binder resin by a shearing force, and is performed at the above-described temperature conditions by a split segment type kneader in which the cylinder and the kneading shaft are divided into a plurality of segments.
[0170]
In the pulverization classification process, the toner lump obtained by kneading and cooling is roughly pulverized by a cutter mill or the like, and then finely pulverized by a jet mill pulverization (for example, IDS pulverizer, Nippon Pneumatic Industry), and further required Accordingly, the fine powder particles are separated by an airflow classifier to obtain toner particles (toner base particles) having a desired particle size distribution. Mechanical pulverization and classification are also possible. For example, a kryptron pulverizer (Kawasaki Heavy Industries) or a turbo mill (a pultron pulverizer that pulverizes toner into a minute gap with a rotating roller with respect to a fixed stator. Turbo industry) is used. This classification process generally yields toner particles (toner base particles) having a volume average particle diameter in the range of 5 to 12 μm, preferably in the range of 5 to 9 μm.
[0171]
The external addition treatment is a treatment in which an external additive such as silica is mixed with the toner particles (toner base particles) obtained by the classification. For this, a known mixer such as a Henschel mixer or a super mixer is used.
[0172]
Moreover, in this form, in order to make the grind | pulverized particle | grains into predetermined particle size distribution, a fine powder is fractionated by classification. The fine powder generated at this time is again mixed with a material such as a binder resin in the preliminary mixing step and reused. This not only reduces the amount of toner discarded as industrial waste, but also leads to cost reduction of the toner itself. When reusing the fine powder, conventionally used polyethylene and polypropylene wax are likely to be non-uniformly dispersed, fog and toner scattering increase, and susceptible to environmental fluctuations. However, even if the classified fine powder toner is reused by using the jojoba oil derivative of this embodiment, fog and toner scattering are not increased. In addition, the ratio of the fine powder toner to be mixed in the preliminary mixing step and the toner base material is created in a ratio of 2:98 to 40:60. When this ratio is larger than 40:60, the mixing property between the finely divided toner and the toner base material is lowered, the dispersibility is not improved, and image fogging and toner scattering are likely to occur. On the other hand, if this ratio is smaller than 2:98, efficiency cannot be satisfied in terms of productivity. Furthermore, by adding metal oxide fine powder or metal acid salt fine powder and surface modification treatment, developability and environmental stability are further improved.
[0173]
Next, the present invention will be described in more detail with reference to examples.
Example 1
(Table 1) shows the monomer composition of the binder resin used in the examples.
[0174]
[Table 1]

[0175]
Table 2 shows the thermal characteristics of the binder resin used in the examples.
[0176]
[Table 2]

[0177]
In Table 2, Tg (° C.) is the glass transition point, Mn is the number average molecular weight, Mw is the weight average molecular weight, Mz is the Z average molecular weight, Tm (° C.), Ti (° C.) are the softening point in the flow tester, and the onset of outflow. Temperature.
[0178]
(Table 3) shows binder resins internally added with jojoba oil derivatives used in the examples.
[0179]
[Table 3]

[0180]
Table 4 shows jojoba oil derivatives used in this example.
[0181]
[Table 4]

[0182]
Table 5 shows the metal oxide fine powder or metal acid salt fine powder used in this example.
[0183]
[Table 5]

[0184]
Table 6 shows the hydrophobic silica used in this example.
[0185]
[Table 6]

[0186]
Table 7 shows the magnetic fine powder used in this example.
[0187]
[Table 7]

[0188]
In Table 7, Md (μm) is the average particle size, Mbet (m 2 / g) is the BET specific surface area, Mr (Ωcm) is the volume resistance, Mad (g / cc) is the bulk density, Mpac (%) is the degree of compression, Mam (ml / 100 g) represents the amount of linseed oil absorbed, Rr (emu / g) represents residual magnetization, and Ss (emu / g) represents saturation magnetization. MG-4 is a sample surface-treated with a titanate coupling agent of isopropyl triisostearoyl titanate.
[0189]
Table 8 shows the carrier material composition used in this example.
[0190]
[Table 8]

[0191]
Table 9 shows the charge control agents and pigments used in this example.
[0192]
[Table 9]

[0193]
Table 10 shows the toner material composition used in this example.
[0194]
[Table 10]

[0195]
The blending ratio of the pigment, charge control agent, and organic material is shown in parentheses in the blending ratio (parts by weight) with respect to 100 parts by weight of the binder resin. The second external additive is a metal oxide fine powder or metal acid salt fine powder. Silica and the second external additive indicate the amount (parts by weight) based on 100 parts by weight of the toner base. Toner No. In A6 and A14, the ratio of the fine powder toner to be mixed in the preliminary mixing step and the toner base material is created at a ratio of 10:90.
[0196]
Table 11 shows the toner base, silica, surface treatment temperature, and material composition of the second external additive when the surface modification treatment used in this example is performed.
[0197]
[Table 11]

[0198]
The toner base is the composition before the external addition treatment described in Table 10, the silica 1 and the second external additive 1 are those before the surface modification treatment, and the silica 2 and the second external additive 2 are the surface modification treatment. It is after.
[0199]
In the surface modification treatment, the raw material supply amount is 1 kg / h, the hot air temperature is about 200 to 350 ° C., and the hot air amount is 3 kg / cm.²0.35 Nm for G^Three/ Min, raw material supply dispersion air volume is 1kg / cm²0.05Nm for G^Three/ Min. The ratio of the hot air flow rate to the raw material supply dispersed air flow rate is preferably in the range of 10: 1 to 4: 1.
[0200]
The external addition process was performed in FM20B with a stirring blade Z0S0 type, a rotational speed of 2000 rpm, a processing time of 5 min, and an input amount of 1 kg.
[0201]
In this embodiment, sufficiently good performance can be obtained even in the two-component development, magnetic one-component development, non-magnetic one-component development, contact type and non-contact type methods.
[0202]
FIG. 2 shows a cross-sectional view of an electrophotographic apparatus used in an embodiment of the electrophotographic method of the present invention. As a developing method, a one-component developing method is used. 201 is an organic photoreceptor, a charge generation layer in which a charge generation material of τ-type metal-free phthalocyanine (manufactured by Toyo Ink) is dispersed in polyvinyl butyral resin (ELEC BL-1 manufactured by Sekisui Chemical) on an aluminum conductive support; A charge transport layer comprising a polycarbonate resin (Z-200 manufactured by Mitsubishi Gas Chemical) and 1,1-bis (P-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene (T-405 manufactured by Annan j) It is the thing of the structure laminated | stacked sequentially. Reference numeral 202 denotes a magnet fixed coaxially with the photosensitive member 201, 203 denotes a corona charger for negatively charging the photosensitive member 201, 204 denotes a grid electrode for controlling the charging potential of the photosensitive member 201, and 205 denotes signal light.
[0203]
Regarding the configuration of the developing device for visualizing the latent image after exposure, 207 is a magnetic one-component toner, 206 is a toner hopper that supplies magnetic toner 207 to the surface of the photoconductor 201, and 208 is a gap between the photoconductor 201 and the gap. 209 is a magnet installed inside the electrode roller 208, 210 is an AC high voltage power source that applies a voltage to the electrode roller 208, and 211 is a polyester film that scrapes off the toner on the electrode roller 208 It is a made scraper. Electrode roller 208 collects excess toner in the non-image area on photoconductor 201.
[0204]
A damper 212 smoothes the flow of the toner 207 in the toner hopper 206 and prevents the toner 207 from being crushed by its own weight and causing clogging between the photosensitive member 201 and the electrode roller 208.
[0205]
Reference numeral 213 denotes a transfer roller for transferring the toner image on the photosensitive member to paper, and is set so that the surface thereof is in contact with the surface of the photosensitive member 201. The transfer roller 213 is an elastic roller provided with a conductive elastic member around a shaft made of a conductive metal. The pressing force to the photosensitive member 201 is 0 to 2000 g, preferably 500 to 1000 g, per transfer roller 213 (about 216 mm). This was measured from the product of the spring coefficient of the spring for pressing the transfer roller 213 against the photosensitive member 201 and the amount of contraction. The contact width with the photoreceptor 201 is about 0.5 mm to 5 mm. The rubber hardness of the transfer roller 213 is 80 degrees or less, preferably 30 to 40 degrees by the Asker C measurement method (measurement using a block piece, not a roller shape). The elastic roller 213 is a foaming urethane elastomer in which a lithium salt such as Li20 is internally added around the shaft having a diameter of 6 mm to make the resistance value 10 7 Ω (electrodes are provided on the shaft and the surface, and 500 V is applied to both). Was used. The entire outer diameter of the transfer roller 213 was 16.4 mm, and the hardness was 40 degrees with Asker C. The transfer roller 213 was brought into contact with the photosensitive member 201 by pressing the shaft of the transfer roller 213 with a metal spring. The pressing force was about 1000 g. As the elastic body of the roller, an elastic body made of other materials such as CR rubber, NBR, Si rubber, fluorine rubber, etc. can be used in addition to the foamable urethane elastomer. In addition to the lithium salt, other conductive substances such as carbon black can be used as the conductivity imparting agent for imparting conductivity.
[0206]
Reference numeral 214 denotes a rush guide made of a conductive member for introducing the transfer paper into the transfer roller 213, and reference numeral 215 denotes a conveyance guide in which the surface of the conductive member is covered with insulation. The entry guide 214 and the conveyance guide 215 are grounded directly or via a resistor. Reference numeral 216 denotes transfer paper, and 217 denotes a voltage generating power source for applying a voltage to the transfer roller 213. Reference numeral 218 denotes a cleaning rubber elastic blade that scrapes off transfer residual toner, and 219 denotes a cleaning box that stores waste toner.
[0207]
The magnetic flux density on the surface of the photoreceptor 201 is 600 Gs. The magnetic force inside the electrode roller 208 was increased to improve the transportability. Further, with respect to the magnetic pole angles of the magnets 202 and 209 shown in the figure, θ was set to 15 degrees. The photosensitive member 201 had a diameter of 30 mm and was rotated at a peripheral speed of 60 mm / s in the direction of the arrow in the figure. The diameter of the electrode roller 208 was 16 mm, and the electrode roller 208 was rotated at a peripheral speed of 40 mm / s in the direction opposite to the traveling direction of the photosensitive member 201 (the arrow direction in the figure). The gap between the photoconductor 201 and the electrode roller 208 was set to 300 μm.
[0208]
The photosensitive member 201 was charged to −500 V with a corona charger 203 (applied voltage −4.5 kV, grid 4 voltage −500 V). The photoreceptor 201 was irradiated with signal light 205 to form an electrostatic latent image. At this time, the exposure potential of the photosensitive member 201 was -90V. A magnetic toner 207 was adhered on the surface of the photoreceptor 201 by a magnetic attraction force of a magnet 202 in a toner hopper 206. Next, the photosensitive member 201 was passed in front of the electrode roller 208. When the photosensitive member 201 passes through the uncharged region, an AC voltage (frequency 1 kHz) of 750 VO-P (1.5 kV peak-to-peak) in which a DC voltage of 0 V is superimposed on the electrode roller 208 by an AC high voltage power supply 210. Was applied. After that, when passing through the photosensitive member 201 charged with −500 V and having an electrostatic latent image written thereon, the electrode roller 208 is 750 VO-P (peak-to-peak) with a DC voltage of −350 V superimposed by the AC high voltage power supply 210. AC voltage (frequency 1 kHz) of 1.5 kV) was applied. As a result, the toner 207 adhered to the non-image area in the charged portion of the photoconductor 201 was collected by the electrode roller 208, and a negative-positive inverted toner image of only the image area remained on the photoconductor 201. The toner adhering to the electrode roller 208 rotating in the direction of the arrow was scraped off by the scraper 211 and returned again into the toner hopper 206 to be used for the next image formation. The toner image thus obtained on the photosensitive member 201 is transferred to the transfer paper 216 by the transfer charger 213 and then thermally fixed by a fixing device (not shown) to obtain a copy image. Table 12 shows the results of the image test.
[0209]
[Table 12]

[0210]
The image evaluation was performed on the occurrence of filming on the photosensitive member, image density, ground fogging, and image quality at the initial stage of image formation and after the endurance test after 10,000 sheets. Filming, ground cover and image quality were judged by visual observation, and it was determined to be acceptable (◯) if there was no practical problem and (×) if there was a practical problem. After that, the image test was performed for each of the 1000 sheets left under high humidity and low humidity, and an increase in fog and a decrease in image density were observed.
[0211]
As a result, in the toner sample A, the horizontal line is not disturbed, the toner is scattered, the transfer is not defective, the back of the paper is not smudged, the character is not omitted, and the solid black image is uniform with no image missing at the rear end of the image portion. Thus, a high density image having an image density of 1.3 or more was obtained. There was no ground cover in the non-image area. When a long-term copy test of 10,000 sheets was performed, there was no filming on the surface of the photoconductor, and a copy image having a high density and less fog compared to the initial image was obtained. Further, fog did not occur under high humidity, and no decrease in concentration occurred even under low humidity.
[0212]
However, in the toner sample J, the image density was decreased, fog was frequently generated under high humidity, and the density was rapidly decreased even under low humidity.
[0213]
(Example 2)
FIG. 3 is a cross-sectional view showing the configuration of the electrophotographic apparatus used in this embodiment. In this embodiment, the FP7742 (manufactured by Matsushita Electric) copier is modified for reversal development and a waste toner recycling mechanism is added.
[0214]
301 is an organophotoreceptor, on which an oxotitanium phthalocyanine powder is deposited on an aluminum conductive support by vapor deposition, and a polycarbonate resin (Mitsubishi Gas Chemical Z-200), butadiene and hydrazone are formed thereon. The charge transport layer containing the mixture is sequentially laminated. Reference numeral 302 denotes a corona charger for negatively charging the photosensitive member, 303 denotes a grid electrode for controlling the charging potential of the photosensitive member, and 304 denotes signal light. 305 is a developing sleeve, 306 is a doctor blade, 307 is a magnet roll for holding a carrier, 308 is a carrier, 309 is toner, 310 is a voltage generator, 311 is waste toner remaining after transfer, 312 is a cleaning box, 313 is cleaning This is a transport pipe for returning the waste toner 311 in the box 312 to the developing process. The toner remaining after transfer is scraped off by a cleaning blade 314, and the waste toner 311 temporarily stored in the cleaning box 312 is returned to the developing process by a transport pipe 313.
[0215]
Reference numeral 314 denotes a transfer roller for transferring the toner image on the photoconductor to paper, and the surface thereof is set so as to come into contact with the surface of the photoconductor 301. The transfer roller 314 is an elastic roller provided with a conductive elastic member around a shaft made of a conductive metal. The basic conditions are the same as in Example 1.
[0216]
Reference numeral 315 denotes a rush guide made of a conductive member for introducing the transfer paper into the transfer roller 314, and 316 denotes a conveyance guide in which the surface of the conductive member is covered with insulation. The entry guide 315 and the conveyance guide 316 are grounded directly or via a resistor. Reference numeral 317 denotes transfer paper, and reference numeral 318 denotes a voltage generating power source for applying a voltage to the transfer roller 314. Table 13 shows the result of the image test.
[0217]
[Table 13]

[0218]
The image evaluation was performed on the occurrence of filming on the photoconductor, image density, ground fogging, and image quality at the initial stage of image formation and after the endurance test after 200,000 sheets. Filming, ground cover, and image quality were judged visually, and if it was at a level that was not a problem for practical use, it was determined to be acceptable (◯). After that, it was left under high humidity and an image test of 1,000 sheets was performed, and an increase in fog was observed. Since the toner density control is poor and over fogging occurs, the fog increases rapidly. In another experiment, the sample was left overnight under high temperature and low humidity, and the image test of 5,000 sheets was performed the next day, and the image density after 5,000 sheets was shown.
[0219]
In Toner Sample A, there is no horizontal line disturbance, toner scattering, transfer failure, paper back stain, no missing characters, solid black image is uniform with no image missing at the rear edge of the image, A high density image having a density of 1.3 or more was obtained. There was no ground cover in the non-image area. Furthermore, when a long-term copying test of 200,000 sheets was conducted, there was no filming on the surface of the photoreceptor, and a copy image having a high density and low-fogging fog that was inferior to the initial image was obtained. In addition, fog did not occur under high humidity, and no decrease in density occurred even under high temperature and low humidity. However, in the toner sample J, a decrease in image density was observed, the toner density exceeded at high humidity and a lot of fogging occurred, and a rapid density decrease occurred at high temperature and low humidity.
[0220]
Using toner sample A, the FP-7750 (manufactured by Matsushita Electric) and FP7722 (manufactured by Matsushita Electric) copiers were modified to provide a high-temperature offset property at a process speed of 140 mm / sec (low speed) and 450 mm / sec ( The fixing rate of the fixing rate at high speed) was evaluated. Table 14 shows the results of the image test.
[0221]
[Table 14]

[0222]
In the toner sample A, the fixing performance at high speed, the high-temperature offset resistance at low speed, and the performance sufficiently satisfactory in practical use were obtained in the high-temperature storage stability test.
[0223]
The fixing rate was 80% or higher, and the offset property was 200 ° C. or higher. The fixing rate is 10 reciprocal rubbing with a 500 g (φ36 mm) weight wound with Bencot (trademark manufactured by Asahi Kasei Co., Ltd.) for each row of patches with an image density of 1.0 ± 0.2, and the image density before and after rubbing is reflected by Macbeth reflection. Measured with a densitometer and defined by the rate of change. 80% or more was accepted. In the storability test, evaluation was performed in a solid state after standing at 50 ° C. for 24 hours. X is considerably hardened and practically NG, and Δ is slightly hard, but there is no practical problem. ○ Evaluated that it was hardly solidified.
[0224]
(Example 3)
FIG. 4 is a cross-sectional view showing the configuration of the electrophotographic apparatus for forming a full-color image used in this embodiment. In FIG. 4, reference numeral 1 denotes an exterior casing of a color electrophotographic printer, and the right end surface side in the figure is the front surface. Reference numeral 1A denotes a printer front plate. The front plate 1A can be freely opened and closed with respect to the printer outer casing 1 around the hinge shaft 1B on the lower side as shown by a dotted line, and can be raised and closed as shown by a solid line. The internal transfer belt unit 2 is attached to and detached from the printer, and internal inspection and maintenance of the printer, such as when a paper jam occurs, is performed by tilting and opening the front plate 1A to largely release the inside of the printer. The attachment / detachment operation of the intermediate transfer belt unit 2 is designed to be perpendicular to the direction of the rotation axis of the photosensitive member.
[0225]
The configuration of the intermediate transfer belt unit 2 is shown in FIG. The intermediate transfer belt unit 2 includes a unit housing 2a, an intermediate transfer belt 3, a first transfer roller 4 made of a conductive elastic body, a second transfer roller 5 made of an aluminum roller, and a tension roller 6 for adjusting the tension of the intermediate transfer belt 3. A belt cleaner roller 7 for cleaning the toner image remaining on the intermediate transfer belt 3, a scraper 8 for scraping off the toner collected on the cleaner roller 7, waste toner reservoirs 9 a and 9 b for collecting the collected toner, and the intermediate transfer belt 3. It includes a position detector 10 that detects the position of. As shown in FIG. 4, the intermediate transfer belt unit 2 is detachably attached to a predetermined storage section in the printer outer casing 1 by opening the printer front plate 1 </ b> A as shown by a dotted line.
[0226]
The intermediate transfer belt 3 is used by kneading a conductive filler in an insulating resin and forming a film with an extruder. In the present example, a film obtained by adding 5 parts by weight of conductive carbon (for example, ketjen black) to 95 parts by weight of polycarbonate resin (for example, Iupilon Z300, manufactured by Mitsubishi Gas Chemical) as the insulating resin was used. The surface was coated with a fluorine resin. The thickness of the film is about 350 μm and the resistance is about 10⁷-10⁸Ω · cm. Here, the use of the intermediate transfer belt 3 in which a conductive filler is kneaded into a polycarbonate resin and used as a film can effectively prevent the intermediate transfer belt 3 from being loosened or accumulated due to long-term use. The reason for this is that the surface is coated with a fluorine resin in order to effectively prevent toner filming on the surface of the intermediate transfer belt due to long-term use.
[0227]
This intermediate transfer belt 3 is made of a film based on a semiconductive urethane having a thickness of 100 μm and having an endless belt shape.⁷It is configured to be wound around a first transfer roller 4, a second transfer roller 5 and a tension roller 6 formed of urethane foam subjected to low resistance treatment so as to have a resistance of Ω · cm, and to be movable in the direction of the arrow. Here, the peripheral length of the intermediate transfer belt 3 is slightly longer than half of the peripheral length of the photosensitive drum (diameter 30 mm), which will be described later, in the length (298 mm) in the longitudinal direction of A4 paper, which is the maximum paper size ( 62 mm) is set to 360 mm.
[0228]
When the intermediate transfer belt unit 2 is mounted on the printer body, the first transfer roller 4 is pressed against the photoconductor 11 (shown in FIG. 5) with a force of about 1.0 kg via the intermediate transfer belt 3, and The second transfer roller 5 is pressed against a third transfer roller 12 (shown in FIG. 5) having the same configuration as the first transfer roller 4 via the intermediate transfer belt 3. The third transfer roller 12 is configured to be driven to rotate by the intermediate transfer belt 3.
[0229]
The cleaner roller 7 is a belt cleaner roller that cleans the intermediate transfer belt 3. This is a configuration in which an AC voltage that electrostatically attracts toner is applied to a metallic roller. The cleaner roller 7 may be a rubber blade or a conductive fur brush to which a voltage is applied.
[0230]
In FIG. 4, in the center of the printer, four sets of fan-shaped image forming units 17Bk, 17Y, 17M, and 17C for each color of black, cyan, magenta, and yellow constitute an image forming unit group 18, as shown in the figure. It is arranged in an annular shape. Each of the image forming units 17Bk, 17Y, 17M, and 17C is detachable at a predetermined position of the image forming unit group 18 by opening the printer upper surface plate 1C around the hinge shaft 1D. When the image forming units 17Bk, 17Y, 17M, and 17C are properly mounted in the printer, the mechanical drive system and the electric circuit system on both the image forming unit side and the printer side are mutually coupled members (not shown). Are combined through mechanical and electrical integration.
[0231]
The image forming units 17Bk, 17C, 17M, and 17Y arranged in an annular shape are supported by a support (not shown), and are driven by a moving motor 19 that is a moving means as a whole, and are fixed and do not rotate. It is comprised so that rotation around the shaft 20 of a shape is possible. Each image forming unit can be positioned at an image forming position 21 facing the second transfer roller 4 that sequentially supports the above-described intermediate transfer belt 3 by rotational movement. The image forming position 21 is also an exposure position by the signal light 22.
[0232]
Each of the image forming units 17Bk, 17C, 17M, and 17Y is composed of the same constituent members except for the developer contained therein, so that the black image forming unit 17Bk will be described for simplifying the description, and for other colors. The description of the unit is omitted. Reference numeral 35 denotes a laser beam scanner unit disposed on the lower side of the printer outer casing 1, and includes a semiconductor laser (not shown), a scanner motor 35a, a polygon mirror 35b, a lens system 35c, and the like. The pixel laser signal light 22 corresponding to the time-series electric pixel signal of the image information from the laser beam scanner unit 35 passes through the optical path window 36 formed between the image forming units 17Bk and 17Y, and a part of the shaft 20 Is incident on the fixed mirror 38 in the shaft 20 through the window 37 opened in the first, and is reflected to enter the image forming unit 17Bk almost horizontally from the exposure window 25 of the image forming unit 17Bk at the image forming position 21; The light passes through the passage between the developer reservoir 26 and the cleaner 34 disposed vertically in the image forming unit, enters the exposure portion on the left side surface of the photoconductor 11, and is scanned and exposed in the direction of the generatrix.
[0233]
Here, since the optical path from the optical path window 36 to the mirror 38 uses a gap between the adjacent image forming units 17Bk and 17Y, the image forming unit group 18 has almost no wasted space. Further, since the mirror 38 is provided in the central portion of the image forming unit group 18, it can be constituted by a single fixed mirror, and is simple and easy to align.
[0234]
Reference numeral 12 denotes a third transfer roller disposed on the inner side of the printer front plate 1A and above the paper feed roller 39. The printer front plate is located at the nip portion where the intermediate transfer belt 3 and the third transfer roller 12 are in pressure contact with each other. A paper transport path is formed so that the paper is fed by a paper feed roller 39 provided at the lower part of 1A.
[0235]
Reference numeral 40 denotes a paper feed cassette provided to protrude outward on the lower side of the printer front plate 1A, and a plurality of paper S can be set simultaneously. 41a and 41b are paper conveyance timing rollers, 42a and 42b are a pair of fixing rollers provided on the inside upper side of the printer, 43 is a paper guide plate provided between the third transfer roller 12 and the pair of fixing rollers 42a and 42b, and 44a and 44b. Is a pair of paper discharge rollers disposed on the paper exit side of the pair of fixing rollers 42a and 42b, 45 is a fixing oil reservoir for storing silicon oil 46 supplied to the fixing roller 42a, and 47 is an oil for applying the silicon oil 46 to the fixing roller 42a. Supply roller.
[0236]
Each of the image forming units 17Bk, 17C, 17M, and 17Y and the intermediate transfer belt unit 2 is provided with a waste toner reservoir.
[0237]
The operation will be described below.
Initially, in the image forming unit group 18, as shown in FIG. 4, the black image forming unit 17 </ b> Bk is at the image forming position 21. At this time, the photoconductor 11 is in opposed contact with the first transfer roller 4 via the intermediate transfer belt 3.
[0238]
In the image forming step, black signal light is input to the image forming unit 17Bk by the laser beam scanner unit 35, and image formation with black toner is performed. At this time, the image forming speed of the image forming unit 17Bk (60 mm / s equal to the peripheral speed of the photosensitive member) and the moving speed of the intermediate transfer belt 3 are set to be the same. 4, the black toner image is transferred to the intermediate transfer belt 3. At this time, a DC voltage of +1 kV was applied to the first transfer roller. Immediately after all the black toner images have been transferred, the image forming units 17Bk, 17C, 17M, and 17Y are driven by the moving motor 19 as a whole as the image forming unit group 18 and rotated and moved in the direction of the arrow in the figure. The image forming unit 17C rotates 90 degrees and stops at the position where it reaches the image forming position 21. During this time, the toner hopper 26 and the cleaner 34 other than the photoconductor of the image forming unit are located on the inner side of the rotating arc at the tip of the photoconductor 11, so that the intermediate transfer belt 3 does not contact the image forming unit.
[0239]
After the image forming unit 17C arrives at the image forming position 21, the laser beam scanner unit 35 inputs the signal light 22 to the image forming unit 17C with a cyan signal as before, and the cyan toner image is formed and transferred. Is called. By this time, the intermediate transfer belt 3 makes one rotation, and the writing timing of the cyan signal light is controlled so that the next cyan toner image is in positional alignment with the previously transferred black toner image. During this time, the third transfer roller 12 and the cleaner roller 7 are slightly separated from the intermediate transfer belt 3 so as not to disturb the toner image on the transfer belt.
[0240]
The same operation as described above was performed for magenta and yellow, and four color toner images were positioned and superimposed on the intermediate transfer belt 3 to form a color image. After the transfer of the last yellow toner image, the four color toner images are collectively transferred by the action of the third transfer roller 12 onto the paper fed from the paper feed cassette 40 at the same timing. At this time, the second transfer roller 5 was grounded, and a DC voltage of +1.5 kV was applied to the third transfer roller 12. The toner image transferred to the paper was fixed by a pair of fixing rollers 42a and 42b. The paper was then discharged out of the apparatus through a pair of discharge rollers 44a and 44b. The remaining transfer toner remaining on the intermediate transfer belt 3 was cleaned by the action of the cleaner roller 7 to prepare for the next image formation.
[0241]
Next, the operation in the monochrome mode will be described. In the single color mode, first, an image forming unit of a predetermined color moves to the image forming position 21. Next, image formation of a predetermined color and transfer to the intermediate transfer belt 3 are performed in the same manner as before, and this time, after the transfer, continues as it is, onto the sheet fed from the paper feed cassette 40 by the next third transfer roller 12. The image was transferred and fixed as it was.
[0242]
In this apparatus, an image forming unit having a structure using a conventional developing method can be used as the structure of the image forming unit. Table 15 shows the formulation of the toner used in this example.
[0243]
[Table 15]

[0244]
Images were formed by the electrophotographic apparatus shown in FIG. When such an electrophotographic apparatus was used to produce an image using the toner sample produced as described above, a solid black image was observed at the rear end of the image area with no horizontal line disturbance, toner scattering, or missing characters. An extremely high resolution and high quality image having a uniform image without image defects and reproducing 16 / mm lines was obtained, and a high density image having an image density of 1.3 or more was obtained. In addition, the ground cover of the non-image area did not occur. Further, even in the long-term durability test of 10,000 sheets, both the fluidity and the image density showed a stable characteristic with little change. Also, in the transfer, the void is at a level that causes no practical problem, and the transfer efficiency is 90%. Further, the filming of the toner (release agent) onto the photosensitive member and the intermediate transfer belt was at a level causing no practical problem.
[0245]
In Table 16, the transmittance when a solid image having an adhesion amount of 0.7 mg / cm 2 or more on OHP paper was fixed at 170 ° C. with a fixing device without applying oil and the offset property at high temperature were evaluated. The process speed was 100 mm / sec, and the transmittance was measured with a spectrophotometer U-3200 (Hitachi), and the transmittance of light at 700 nm was measured. A satisfactory result was obtained in practical use.
[0246]
[Table 16]

[0247]
【The invention's effect】
As described above, according to the present invention, the dispersibility of the internal additive such as wax in the binder resin is improved, the occurrence of fogging in the non-image area, the image defect at the rear end of the solid black image area, Further, it is possible to prevent filming on the photoconductor.
Further, according to the present invention, a stable image can be obtained even if the fine powder toner classified by classification is reused by mixing.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing the configuration of an example of a surface modification processing apparatus used for a toner of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of an electrophotographic apparatus for one-component development used in an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a configuration of an electrophotographic apparatus used in an example of the present invention.
FIG. 4 is a cross-sectional view showing a schematic configuration of a color electrophotographic apparatus used in an example of the present invention.
FIG. 5 is a cross-sectional view showing the configuration of the intermediate transfer belt unit shown in FIG.
FIG. 6 is a sectional view showing a schematic configuration of a color electrophotographic apparatus.
[Explanation of symbols]
2 Intermediate transfer belt unit
3 Intermediate transfer belt
4 First transfer roller
5 Second transfer roller
6 Tension roller
11 photoconductor
12 Third transfer roller
17Bk, 17C, 17M, 17Y Image forming unit
18 Image forming units
21 Image forming position
22 Laser signal light
35 Laser beam scanner
38 mirror
103 Compressed air
104 Dispersing nozzle
105 Hot air generator
109 Cooling air
110 Cyclone
113 Air flow meter
201 photoconductor
203 Corona charger
204 Grid electrode
207 Toner
208 Development sleeve
213 Transfer roller
214 Entry Guide
215 Transport guide
216 transfer paper
218 Cleaning blade
219 Cleaning box
308 Career
305 Development sleeve
306 Doctor Blade
307 Magnet roll
314 Cleaning blade
312 Cleaning box
311 Waste toner
313 Waste toner transport pipe

Claims (12)

At least the weight average molecular weight Mw is 10,000 to 300,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 3 to 50, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 10 to 800. Polyester resin obtained by polycondensation of polyhydric carboxylic acid or its lower alkyl ester and polyhydric alcohol, whose 1/2 outflow temperature is 80 to 150 ° C. and outflow start temperature is 80 to 120 ° C. toner a binder resin, a colorant, a toner base and a jojoba oil derivative, wherein the early days including the external additive including a. At least the weight average molecular weight Mw is 10,000 to 300,000, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 3 to 50, and the ratio Mz / Mn of the Z average molecular weight Mz to the number average molecular weight Mn is 10 to 800. Polyester resin obtained by polycondensation of polyhydric carboxylic acid or its lower alkyl ester and polyhydric alcohol, whose 1/2 outflow temperature is 80 to 150 ° C. and outflow start temperature is 80 to 120 ° C. A binder resin containing
Flat ratio Hitoshitsubu diameter and a and 25% residual diameter D25 0.02~2.0μm 75% residual diameter D75 D25 / D75 is within a range of 1.3 to 1.7, BET specific surface area by nitrogen adsorption Is 0.5 to 80 m ² / g, electrical resistance is 10 ² to 10 ¹¹ Ωcm, bulk density is 0.3 to 0.9 g / cc, and compressibility is 30 to 80%. A toner base having an amount of 10 to 30 (ml / 100 g), a residual magnetization of 5 to 20 emu / g, a saturation magnetization of 40 to 80 emu / g, a jojoba oil derivative, and an external additive A toner comprising: E Hoba oil derivatives, jojoba oil fatty acid, metal salts of jojoba oil fatty acid, jojoba oil fatty acid esters, hydrogenated jojoba oil, jojoba oil amide, Homohohoba oil amide, jojoba oil triester, maleic acid derivatives of epoxidized jojoba oil, jojoba The toner according to claim 1 , wherein the toner is one or more selected from the group consisting of an isocyanate polymer of an oil fatty acid polyhydric alcohol ester . The toner according to claim 3 , wherein the jojoba oil triester is a jojoba oil triester obtained by epoxidizing jojoba oil and acylating after hydration ring opening . The toner according to claim 3 , wherein the metal salt of jojoba oil fatty acid is a metal salt of sodium, potassium, calcium, magnesium, barium, zinc, lead, manganese, iron, nickel, cobalt, or aluminum . Titanium coupling agents a magnetic material, silane coupling agent, an epoxy silane coupling agent, acrylic silane coupling agents, or claim 2, wherein the treated with at least one or more coupling agents selected from aminosilane coupling agent Toner. Binder resin, the toner according to claim 1 or 2, wherein a main component that jojoba oil derivative was added to a binder resin solution, the solvent was removed. At least one of titanate fine powder or zirconia acid fine powder whose external additive has an average particle diameter of 0.02 to 4 μm and a BET specific surface area by nitrogen adsorption of 0.1 to 100 m ² / g the toner according to claim 1 or 2, wherein comprising a metal salt-based powder having the above. The toner according to claim 8 , wherein the metal salt-based fine powder is prepared by a hydrothermal method or an oxalate pyrolysis method . The external additive has an average particle size of 0.02 to ² μm, a BET specific surface area by nitrogen adsorption of 0.1 to 100 m ² / g, and an electrical resistivity of 10 ⁹ Ωcm or less, a fine powder of titanium oxide, a fine powder of aluminum oxide, strontium oxide powder, tin oxide powder, zirconium oxide powder, magnesium oxide powder, the toner according to claim 1 or 2 wherein comprises a metal oxide powder consisting of at least one or more of the powder of indium oxide fine powder. The external additive contains a metal oxide fine powder comprising titanium oxide and / or silica oxide fine powder surface-treated with a mixture of tin oxide and antimony having a BET specific surface area of 1 to 200 m ² / g by nitrogen adsorption. The toner according to 1 or 2 . The external additive has an average particle diameter of 0.02 to 2.0 μm and a ratio D25 / D75 of 25% residual diameter D25 to 75% residual diameter D75 is in the range of 1.3 to 1.7, and nitrogen adsorption BET specific surface area is 0.5 to 80 m ² / g, electrical resistance is 10 ² to 10 ¹¹ Ωcm, bulk density is 0.3 to 0.9 g / cc, and compressibility is 30 to 80%. a linseed oil absorption amount is 10~30 (ml / 100g), residual magnetization 5~20emu / g, the toner of claim 1 or 2, wherein the saturation magnetization containing magnetic fine powder is 40~80emu / g .

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