JP2004219488A - Electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having a sharp charge amount distribution, excellent fine dot reproducibility, anti-offset properties, filming resistance and cleanability over a prolonged period of time and adaptable to a low temperature fixing system, and to provide a developer using the toner, a developing method, a toner vessel and a developing device. <P>SOLUTION: The electrostatic charge image developing toner is a dry toner containing at least a modified polyester resin, a colorant and a release agent. The toner is obtained as follows: an emulsified dispersion is obtained by reacting a solution or dispersion formed by dissolving or dispersing, in an organic solvent, a toner composition which contains a toner binder component comprising a modified polyester resin capable of reacting with a compound having an active hydrogen group with a compound having an active hydrogen group in an aqueous medium containing fine resin particles; the resultant emulsified dispersion is mixed with an aqueous solution containing at least a thickener; the organic solvent concentration of the resulting mixed solution is adjusted to 3 to 15 wt.%; the mixed solution is passed through a unit which applies shearing force to the mixed solution to make a prepared toner aspherical; the solvent is removed; and the fine resin particles sticking to the toner surface are washed/released. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

標準物質に、ｎ−ヘキサンを用いて検量線を作成し、有機溶媒濃度を求めた。
【００７７】
また、せん断力を調整する方法は、装置の処理時間や処理回数、分散液の温度、粘度、粒子中の有機溶媒の濃度等が挙げられる。また、粒子自身も、粒子表面の有機微粒子の被覆率、伸長及び／又は架橋反応度等の違いにより、せん断力による変形の度合いも異なり得られる形状に差が出る。
本発明において、前記混合溶液にせん断力を与える時の前記有機溶媒の濃度は、３〜１５重量％であることが重要であり、特に４〜１２重量％が好ましい。さらに、混合溶液の粘度は２５００〜２５０００ｍＰａ・ｓが好ましく、特に４０００〜２００００ｍＰａ・ｓが好ましい。さらに処理温度は２０〜３５℃が好ましい。
【００７８】
得られた乳化分散体から有機溶媒を除去するためには、系全体を徐々に昇温し、液滴中の有機溶媒を完全に蒸発除去する方法を採用することができる。あるいはまた、乳化分散体を乾燥雰囲気中に噴霧して、液滴中の非水溶性有機溶媒を完全に除去してトナー微粒子を形成し、合せて水系分散剤を蒸発除去することも可能である。乳化分散体が噴霧される乾燥雰囲気としては、空気、窒素、炭酸ガス、燃焼ガス等を加熱した気体、特に使用される最高沸点溶媒の沸点以上の温度に加熱された各種気流が一般に用いられる。スプレイドライアー、ベルトドライアー、ロータリーキルンなどの短時間の処理で十分目的とする品質が得られる。
【００７９】
乳化分散時の粒度分布が広く、その粒度分布を保って洗浄、乾燥処理が行われた場合、所望の粒度分布に分級して粒度分布を整えることができる。
分級操作は液中でサイクロン、デカンター、遠心分離等により、微粒子部分を取り除くことができる。もちろん乾燥後に粉体として取得した後に分級操作を行っても良いが、液体中で行うことが効率の面で好ましい。得られた不要の微粒子、または粗粒子は再び混練工程に戻して粒子の形成に用いることができる。その際微粒子、または粗粒子はウェットの状態でも構わない。
【００８０】
用いた分散剤は得られた分散液からできるだけ取り除くことが好ましいが、先に述べた分級操作と同時に行うのが好ましい。
得られた乾燥後のトナーの粉体と離型剤微粒子、帯電制御性微粒子、流動化剤微粒子、着色剤微粒子などの異種粒子とともに混合したり、混合粉体に機械的衝撃力を与えることによって表面で固定化、融合化させ、得られる複合体粒子の表面からの異種粒子の脱離を防止することができる。
【００８１】
具体的手段としては、高速で回転する羽根によって混合物に衝撃力を加える方法、高速気流中に混合物を投入し、加速させ、粒子同士または複合化した粒子を適当な衝突板に衝突させる方法などがある。装置としては、オングミル（ホソカワミクロン社製）、Ｉ式ミル（日本ニューマチック社製）を改造して、粉砕エアー圧力を下げた装置、ハイブリダイゼイションシステム（奈良機械製作所社製）、クリプトロンシステム（川崎重工業社製）、自動乳鉢などがあげられる。
【００８２】
本発明のトナーの非球形の形状は、紡錘状が好ましく、特に均一な紡錘状が好ましい。
トナー形状が一定しない不定形、又は扁平形状では粉体流動性が悪いことから、次のような課題を持つ。摩擦帯電が円滑に行えないことから地肌汚れ等の問題が発生しやすい。微小な潜像ドットを現像する際には、緻密で均一なトナー配置をとりにくいことから、ドット再現性に劣る。静電転写方式では、電気力線の影響を受けにくく、転写効率が劣る。
トナーが真球に近い場合、粉体流動性が良すぎて、外力に対して過度に作用してしまうことから、現像及び転写の際に、ドットの外側にトナー粒子が飛び散りやすいといった問題がある。また、球形トナーでは、感光体上で転がりやすいために、感光体とクリーニング部材との間に潜り込みクリーニング不良となることが多いという問題点がある。
【００８３】
本発明の紡錘形状のトナーは、粉体流動性が適度に調節されているために、摩擦帯電が円滑に行われて地肌汚れを発生させることがなく、微小な潜像ドットに対して整然と現像され、その後、効率よく転写されてドット再現性に優れる。更に、その際の飛び散りに対しては、粉体流動性が適度にブレーキをかけて飛び散りを防いでいる。紡錘形状のトナーは球形トナーに比べて、転がる軸が限られていることから、クリーニング部材の下に潜り込むようなクリーニング不良が発生しにくい。
【００８４】
トナー形状を図１（ａ）及び（ｂ）に基づいて説明する。
本発明の紡錘形状のトナーは、短軸と長軸との比（ｒ_２／ｒ_１）が０．５〜０．８で、厚さと短軸との比（ｒ_３／ｒ_２）が０．７〜１．０で表される紡錘形状であることが好ましい。
短軸と長軸との比（ｒ_２／ｒ_１）が０．５未満では、真球形状から離れるためにクリーニング性が高いが、ドット再現性及び転写効率が劣るために高品位な画質が得られなくなる。一方短軸と長軸との比（ｒ_２／ｒ_１）が０．８を越えると、球形に近づくために、低温低湿の環境下では特にクリーニング不良が発生することがある。
また、厚さと短軸との比（ｒ_３／ｒ_２）が０．７未満では、扁平形状に近く、不定形トナーのように飛び散りは少ないが、球形トナーのような高転写率は得られない。特に、厚さと短軸との比（ｒ_３／ｒ_２）が１．０では、長軸を回転軸とする回転体となる。これに近い紡錘形状にすることで不定形・扁平形状でもなく真球状でもない形状であって、双方の形状が有する摩擦帯電性、ドット再現性、転写効率、飛び散りの防止性、クリーニング性の全てを満足させる形状となる。なお、ｒ_１、ｒ_２、ｒ_３は、走査型電子顕微鏡（ＳＥＭ）で、視野の角度を変えて写真を撮り、観察しながら測定した。
【００８５】
本発明においてトナーの形状の測定は、フロー式粒子像分析装置ＦＰＩＡ−２１００（シスメックス（株）製）により行うことができる。
トナー形状（円形度）の計測方法としては、粒子を含む懸濁液を平板上の撮像部検知帯に通過させ、ＣＣＤカメラで光学的に粒子画像を検知し、解析する光学的検知帯の手法が適当である。この手法では粒子の投影面積が得られるが、円形度は、この投影面積と面積の等しい相当円の周囲長を実在粒子の周囲長で除した値である。この値はフロー式粒子像分析装置ＦＰＩＡ−２１００により平均円形度として計測した値である。具体的な測定方法としては、容器中の予め不純固形物を除去した水１００〜１５０ｍｌ中に分散剤として界面活性剤、好ましくはアルキルベンゼンスフォン酸塩を０．１〜０．５ｍｌ加え、更に測定試料を０．１〜０．５ｇ程度加える。試料を分散した懸濁液は超音波分散器で約１〜３分間分散処理を行ない、分散液濃度を３０００〜１万個／μｌとして前記装置によりトナーの形状及びトナーの形状分布を測定する。
【００８６】
（二成分用キャリア）
本発明のトナーを二成分系現像剤に用いる場合には、磁性キャリアと混合して用いれば良く、現像剤中のキャリアとトナーの含有比は、キャリア１００重量部に対してトナー１〜１０重量部が好ましい。磁性キャリアとしては、粒子径２０〜２００μｍ程度の鉄粉、フェライト粉、マグネタイト粉、磁性樹脂キャリアなど従来から公知のものが使用できる。
【００８７】
また、キャリアは裏面を被覆してもよく、被覆材料としては、アミノ系樹脂、例えば尿素−ホルムアルデヒド樹脂、メラミン樹脂、ベンゾグアナミン樹脂、ユリア樹脂、ポリアミド樹脂、エポキシ樹脂等があげられる。またポリビニルおよびポリビニリデン系樹脂、例えばアクリル樹脂、ポリメチルメタクリレート樹脂、ポリアクリロニトリル樹脂、ポリ酢酸ビニル樹脂、ポリビニルアルコール樹脂、ポリビニルブチラール樹脂、ポリスチレン樹脂およびスチレンアクリル共重合樹脂等のポリスチレン系樹脂、ポリ塩化ビニル等のハロゲン化オレフィン樹脂、ポリエチレンテレフタレート樹脂およびポリブチレンテレフタレート樹脂等のポリエステル系樹脂、ポリカーボネート系樹脂、ポリエチレン樹脂、ポリ弗化ビニル樹脂、ポリ弗化ビニリデン樹脂、ポリトリフルオロエチレン樹脂、ポリヘキサフルオロプロピレン樹脂、弗化ビニリデンとアクリル単量体との共重合体、弗化ビニリデンと弗化ビニルとの共重合体、テトラフルオロエチレンと弗化ビニリデンと非弗化単量体とのターポリマー等のフルオロターポリマー、およびシリコーン樹脂等が使用できる。
【００８８】
また必要に応じて、導電粉等を被覆樹脂中に含有させてもよい。導電粉としては、金属粉、カーボンブラック、酸化チタン、酸化錫、酸化亜鉛等が使用できる。これらの導電粉は、平均粒子径１μｍ以下のものが好ましい。平均粒子径が１μｍよりも大きくなると、電気抵抗の制御が困難になる。
【００８９】
また、本発明のトナーはキャリアを使用しない一成分系の磁性トナー、或いは非磁性トナーとしても用いることができる。
【００９０】
【実施例】
以下実施例により本発明を更に説明するが、本発明はこれに限定されるものではない。尚、部は重量部を示す。
【００９１】
実施例１
（有機微粒子エマルションの合成）
製造例１
攪拌棒および温度計をセットした反応容器に、水６８３部、メタクリル酸エチレンオキサイド付加物硫酸エステルのナトリウム塩（エレミノールＲＳ−３０、三洋化成工業製）１１部、スチレン８３部、メタクリル酸８３部、アクリル酸ブチル１１０部、過硫酸アンモニウム１部を仕込み、４００回転／分で１５分間攪拌したところ、白色の乳濁液が得られた。加熱して、系内温度７５℃まで昇温し５時間反応させた。さらに、１％過硫酸アンモニウム水溶液３０部加え、７５℃で５時間熟成してビニル系樹脂（スチレン−メタクリル酸−アクリル酸ブチル−メタクリル酸エチレンオキサイド付加物硫酸エステルのナトリウム塩の共重合体）の水性分散液［微粒子分散液１］を得た。［微粒子分散液１］をＬＡ−９２０で測定した体積平均粒径は、０．１０μｍであった。［微粒子分散液１］の一部を乾燥して樹脂分を単離した。該樹脂分のＴｇは５７℃であった。
【００９２】
（水相の調製）
製造例２
水９９０部、［微粒子分散液１］８０部、ドデシルジフェニルエーテルジスルホン酸ナトリウムの４８．５％水溶液（エレミノールＭＯＮ−７）：三洋化成工業製）４０部、酢酸エチル９０部を混合攪拌し、乳白色の液体を得た。これを［水相１］とする。
【００９３】
（低分子ポリエステルの合成）
製造例３
冷却管、攪拌機および窒素導入管の付いた反応容器中に、ビスフェノールＡエチレンオキサイド２モル付加物２２０部、ビスフェノールＡプロピレンオキサイド３モル付加物５６１部、テレフタル酸２１８部、アジピン酸４８部およびジブチルチンオキサイド２部を入れ、常圧２３０℃で８時間反応し、さらに１０〜１５ｍｍＨｇの減圧で５時聞反応した後、反応容器に無水トリメリット酸４５部を入れ、１８０℃、常圧で２時間反応し、［低分子ポリエステル１］を得た。［低分子ポリエステル１〕は、数平均分子量２５００、重量平均分子量６７００、Ｔｇ４３℃、酸価２５であった。
【００９４】
（プレポリマーの合成）
製造例４
冷却管、攪拌機および窒索導入管の付いた反応容器中に、ビスフェノールＡエチレンオキサイド２モル付加物６８２部、ビスフェノールＡプロピレンオキサイド２モル付加物８１部、テレフタル酸２８３部、無水トリメリット酸２２部およびジブチルチンオキサイド２部を入れ、常圧２３０℃で８時間反応し、さらに１０〜１５ｍｍＨｇの減圧で５時間反応した［中間体ポリエステル１］を得た。［中間体ポリエステル１］は、数平均分子量２１００、重量平均分子量９５００、Ｔｇ５５℃、酸価０．５、水酸基価４９であった。
次に、冷却管、攪拌機および窒素導入管の付いた反応容器中に、［中間体ポリエステル１］４１１部、イソホロンジイソシアネート８９部、酢酸エチル５００部を入れ１００℃で５時間反応し、［プレポリマー１］を得た。［プレポリマー１］の遊離イソシアネート重量％は、１．５３％であった。
【００９５】
（ケチミンの合成）
製造例５
攪拌棒および温度計をセットした反応容器に、イソホロンジアミン１７０部とメチルエチルケトン７５部を仕込み、５０℃で５時間反応を行い、［ケチミン化合物１］を得た。［ケチミン化合物１］のアミン価は４１８であった。
【００９６】
（マスターバッチの合成）
製造例６
カーボンブラック（キャボット社製 リーガル４００Ｒ）：４０部、結着樹脂：ポリエステル樹脂（三洋化成ＲＳ−８０１ 酸価１０、Ｍｗ２００００、Ｔｇ６４℃）：６０部、水：３０部をヘンシェルミキサーにて混合し、顔料凝集体中に水が染み込んだ混合物を得た。これをロ−ル表面温度１３０℃に設定した２本ロールにより４５分間混練を行ない、パルベライザーで１ｍｍφの大きさに粉砕し、［マスターバッチ１］を得た。
【００９７】
（油相の作成）
製造例７
攪拌棒および温度計をセットした容器に、［低分子ポリエステル１］３７８部、カルナバＷＡＸ１１０部、ＣＣＡ（サリチル酸金属錯体Ｅ−８４：オリエント化学工業製）２２部、酢酸エチル９４７部を仕込み、攪拌下８０℃に昇温し、８０℃のまま５時間保持した後、１時間で３０℃に冷却した。次いで容器に［マスターバッチ１］５００部、酢酸エチル５００部を仕込み、１時間混合し［原料溶解液１］を得た。
［原料溶解液１］１３２４部を容器に移し、ビーズミル（ウルトラビスコミル、アイメックス社製）を用いて、送液速度１ｋｇ／ｈｒ、ディスク周速度６ｍ／秒、０．５ｍｍジルコニアビーズを８０体積％充填、３パスの条件で、カーボンブラック、ＷＡＸの分散を行った。次いで、［低分子ポリエステル１］の６５％酢酸エチル溶液１３２４部加え、上記条件のビーズミルで１パスし、［顔料・ＷＡＸ分散液１］を得た。［顔料・ＷＡＸ分散液１］の固形分濃度（１３０℃、３０分）は５０％であった。
【００９８】
（乳化）
製造例８
［顔料・ＷＡＸ分散液１］６４８部、［プレポリマー１］を１５４部、［ケチミン化合物１］６．６部を容器に入れ、ＴＫホモミキサー（特殊機化製）で５，０００ｒｐｍで１分間混合した後、容器に［水相１］１２００部を加え、ＴＫホモミキサーで、回転数１３，０００ｒｐｍで２０分間混合し［乳化スラリー１］を得た。
【００９９】
（異形化）
製造例９
イオン交換水１３６５部、カルボキシメチルセルロース（ＣＭＣダイセル−１２８０：ダイセル化学工業（株）製）３５部容器に入れて攪拌した水溶液に、［乳化スラリー１］１０００部を混合し、Ｔ．Ｋ．パイプラインホモミキサー型式：ＰＬ−２Ｖ（特殊機化製）で２，０００ｒｐｍで流量１０００ｇ／ｍｉｎで流し、［異形化スラリー１］を得た。このときの異形化スラリー１の粘度は４０００ｍＰａ・ｓであった。
【０１００】
（脱溶剤）
製造例１０
攪拌機および温度計をセットした容器に、［異形化スラリー１］を投入し、３０℃で８時間脱溶剤した後、４５℃で４時間熟成を行い、［分散スラリー１］を得た。
【０１０１】
（洗浄⇒乾燥）
［分散スラリー１］１００部を減圧濾過した後、
▲１▼：濾過ケーキにイオン交換水１００部を加え、ＴＫホモミキサーで混合（回転数１２，０００ｒｐｍで１０分間）した後濾過した。
▲２▼：▲１▼の濾過ケーキに１０％水酸化ナトリウム水溶液１００部を加え、超音波振動を付与してＴＫホモミキサーで混合（回転数１２，０００ｒｐｍで３０分間）した後、減圧濾過した。この超音波アルカリ洗浄を再度行った（超音波アルカリ洗浄２回）。
▲３▼：▲２▼の濾過ケーキに１０％塩酸１００部を加え、ＴＫホモミキサーで混合（回転数１２，０００ｒｐｍで１０分間）した後濾過した。
▲４▼：▲３▼の濾過ケーキにイオン交換水３００部を加え、ＴＫホモミキサーで混合（回転数１２，０００ｒｐｍで１０分間）した後濾過する操作を２回行い［濾過ケーキ１］を得た。
［濾過ケーキ１］を循風乾燥機にて４５℃で４８時間乾燥し、目開き７５μｍメッシュで篩い、［トナー母体１］を得た。
【０１０２】
比較例１
実施例１のＴ．Ｋ．パイプラインホモミキサー型式：ＰＬ−２Ｖ（特殊機化製）で２，０００ｒｐｍで流量１０００ｇ／ｍｉｎで流したことを実施しなかった以外は実施例１と同様に［トナー母体５］を得た。
【０１０３】
実施例２〜４、比較例２〜４
実施例１（製造例９）の粘度Ｐと有機溶媒濃度を表１に示すように増粘剤とイオン交換水の濃度を変更し、異形化スラリーの粘度を表１に示すように調整した以外は実施例１と同様に［トナー母体２〜４及び６〜８］を得た。
【０１０４】
（形状の測定）
非球形の判定は、光学顕微鏡を用いて、図６の写真のように真球状のものをランク１とし、図５の写真のようにほぼ球状のものをランク２、図４の写真のように紡錘状（ラグビーボール）と球状が半分ぐらいあるものをランク３、図３の写真のように紡錘状だが不揃いのものをランク４、図２の写真のようにすべて紡錘状で均一なものをランク５とし、形状をランク分けして判断した。本発明において、非球形化されたものとは、ランク３以上のものを云う。
また、長期にわたってクリーニング性を保持するには形状ランク４以上で、フロー式粒子像分析装置によって測定される個数基準の円相当径で２．０μｍ未満の粒子が２５個数％以下が有効である。円相当径で２．０μｍ未満の粒子の測定は（株）ＳＹＳＭＥＸ製フロー式粒子像分析装置ＦＰＩＡ−１０００を用いて測定することができる。装置および測定の概略は特開平８−１３６４３９号公報に記載されている。測定は、１級塩化ナトリウムを用いて１％ＮａＣｌ水溶液に調整した後０．４５μｍのフィルターを通した液５０〜１００ｍｌに分散剤として界面活性剤、好ましくはアルキルベンゼンスルフォン酸塩を０．１〜５ｍｌ加え、試料を１〜１０ｍｇ加える。これを、超音波分散機で１分間の分散処理を行ない、粒子濃度を５０００〜１５０００個／μｌに調整した分散液を用いて測定を行なった。粒子個数の測定は、ＣＣＤカメラで撮像した２次元の画像面積と、同一の面積を有する円の直径を円相当径として算出を行なう。ＣＣＤの画素の精度から、円相当径で０．６μｍ以上を有効とし粒子の測定データを得た。
各トナー母体の形状のランクを表１に示す。
【０１０５】
【表１】

【０１０６】
前記のようにして得られたトナー母体１〜８各々１００部に疎水性シリカ０．７部と、疎水化酸化チタン０．３部をヘンシェルミキサーにて混合した。
【０１０７】
外添剤処理を施した各トナー５重量％とシリコーン樹脂を被覆した平均粒子径が４０μｍの銅−亜鉛フェライトキャリア９５重量％からなる現像剤を調製し、毎分Ａ４サイズの用紙を４５枚印刷できるリコー製ｉｍａｇｉｏ Ｎｅｏ ４５０を用いて、連続印刷して下記の方法及び基準で評価し、表２に示した。
【０１０８】
［評価方法及び評価基準］
（クリーニング性）
清掃工程を通過した感光体上の転写残トナーをスコッチテープ（住友スリーエム（株）製）で白紙に移し、それをマクベス反射濃度計ＲＤ５１４型で測定し、ブランクとの差が０．０１以下のものを○（良好）、それを越えるものを×（不良）として評価した。
【０１０９】
（耐フィルミング性）
現像ローラまたは感光体上のトナーフィルミング発生状況の有無を観察した。○はフィルミングがなく、△はスジ上のフィルミングが見られ、×は全体的にフィルミングがあるとして評価した。
【０１１０】
【表２】

【０１１１】
【発明の効果】
本発明により、長期にわたって、耐フィルミング性、クリーニング性に優れた、低温定着システムに対応する静電荷像現像用トナーを提供することができる。また本発明により、上記トナーを用いる現像剤、現像方法、及び該トナーを充填したトナー容器、現像装置を提供することができる。
【図面の簡単な説明】
【図１】トナー形状を説明するための図である。
【図２】トナー母体形状のランク５（均一な紡錘状）のものを示すためのトナーの光学顕微鏡を用いた写真である。
【図３】トナー母体形状のランク４（不揃いの紡錘状）のものを示すためのトナーの光学顕微鏡を用いた写真である。
【図４】トナー母体形状のランク３（紡錘状と球状が半々程度）のものを示すためのトナーの光学顕微鏡を用いた写真である。
【図５】トナーの母体形状のランク２（ほぼ球状）のものを示すためのトナーの光学顕微鏡を用いた写真である。
【図６】トナーの母体形状のランク１（真球状）のものを示すためのトナーの光学顕微鏡を用いた写真である。
【符号の説明】
ｒ_１ トナーの長軸
ｒ_２ トナーの短軸
ｒ_３ トナーの厚さ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner for developing an electrostatic image, a developer, a developing method, a toner container, and a developing device for visualizing an electrostatic image formed on the surface of a photoconductor in electrophotography, electrostatic recording, and the like.
[0002]
[Prior art]
Conventionally, in an electrophotographic apparatus, an electrostatic recording apparatus, or the like, an electric or magnetic latent image is visualized by toner. For example, in electrophotography, a toner image is formed by forming an electrostatic charge image (latent image) on a photoreceptor, and then developing the latent image using toner. The toner image is usually transferred onto a transfer material such as paper, and then fixed by a method such as heating. The toner used for electrostatic image development is generally a colored particle containing a colorant, a charge control agent, and other additives in a binder resin.The production method is roughly classified into a pulverization method and a pulverization method. There is a suspension polymerization method. In the pulverization method, a colorant, a charge controlling agent, an anti-offset agent, and the like are melt-mixed and uniformly dispersed in a thermoplastic resin, and the resulting composition is pulverized and classified to produce a toner. According to the pulverization method, it is possible to produce a toner having excellent properties to some extent, but there is a limitation in selecting a toner material. For example, compositions obtained by melt mixing must be able to be ground and classified by equipment that can be used economically. Due to this requirement, the melt-mixed composition must be made sufficiently brittle. For this reason, when actually pulverizing the composition into particles, a wide range of particle size distribution is likely to be formed, and in order to obtain a copied image with good resolution and gradation, for example, a particle size of 5 μm The following fine powder and coarse powder having a size of 20 μm or more must be removed by classification, resulting in a disadvantage that the yield is extremely low. Further, in the pulverization method, it is difficult to uniformly disperse a colorant, a charge control agent, and the like in a thermoplastic resin. Non-uniform dispersion of the compounding agent adversely affects the fluidity, developability, durability and image quality of the toner.
[0003]
In recent years, in order to overcome the problems in these pulverization methods, a method for producing a toner by a suspension polymerization method has been proposed and implemented. A technique for producing a toner for developing an electrostatic latent image by a polymerization method is known. For example, toner particles are obtained by a suspension polymerization method. However, the toner particles obtained by the suspension polymerization method are spherical and have a disadvantage that cleaning properties are poor. The most important problem is that it is difficult to completely remove the transfer residual toner on the surface of the image carrier by the cleaning means, and cleaning failure occurs. In particular, in the blade cleaning method, at the time of cleaning, the toner becomes close to the close-packed state between the contact portion of the image carrier and the cleaning blade, and the toner of the first layer having a strong adhesive force to the image carrier and The toner slips between the second-layer toner and the first-layer toner, and remains on the image carrier as cleaning failure.
[0004]
In order to solve such a problem, the following plans have been proposed.
<JP-A-5-265360 (Patent Document 1)>
In a cleaning method of an image forming apparatus in which a cleaning blade is pressed against a surface of an image carrier to remove residual toner on the surface of the image carrier, a conductive member is used for the cleaning blade, and an AC bias voltage and a toner A cleaning method comprising applying a DC bias voltage having the same polarity as a charged charge to remove residual toner on the surface of an image carrier.
<JP-A-7-210053 (Patent Document 2)>
In a cleaning device of an electrophotographic apparatus for cleaning the surface of a photoreceptor by scraping residual toner on the photoreceptor after transfer with a cleaning blade, the cleaning blade is made of a conductive material and grounded. Alternatively, a DC voltage having a polarity opposite to that of the residual toner is applied. Alternatively, a DC voltage having the same polarity as that of the residual toner is applied. Alternatively, it has been proposed to apply an AC voltage thereto.
[0005]
However, the method described in any of the publications has an effect of cleaning by bringing a cleaning blade into contact with an image carrier and scraping off the toner. In the case of a toner using a toner binder, so-called wax filming occurs in which wax existing near the surface inside the toner resin exudes to the surface due to the pressure and is rubbed against the image carrier and adheres. In addition, the charging roller and the like that contactly charge the photoconductor are contaminated, and the original charging ability cannot be exhibited. Further, it is conceivable to improve the toner by devising an external additive, but it was not possible to obtain a sufficient cleaning property.
[0006]
In addition, a method has been proposed in which irregular resin particles are obtained by associating resin fine particles obtained by an emulsion polymerization method, but this method causes the following problems. When releasing agent fine particles are associated to improve offset resistance, the releasing agent fine particles are taken into the toner particles, and as a result, the offset resistance cannot be sufficiently improved. . Since toner particles are formed by randomly fusing resin fine particles, release agent fine particles, colorant fine particles, and the like, the composition (content ratio of the constituent components) and the molecular weight of the constituent resin vary among the obtained toner particles. As a result, toner particles have different surface characteristics, and a long-term stable image cannot be formed. Further, in a low-temperature fixing system that requires low-temperature fixing, fixing hindrance occurs due to resin fine particles unevenly distributed on the toner surface, and a fixing temperature range cannot be secured.
[0007]
[Patent Document 1]
JP-A-5-265360
[Patent Document 2]
JP-A-7-210053
[0008]
[Problems to be solved by the invention]
The present invention has been made based on the above circumstances.
A first object of the present invention is to provide a toner for developing an electrostatic image that is compatible with a low-temperature fixing system and has excellent filming resistance while maintaining excellent cleaning properties for a long period of time.
A second object of the present invention is to provide a developer using the toner, a developing method, a toner container, and a developing device.
[0009]
[Means for Solving the Problems]
Generally, in order to obtain a high-resolution and high-quality image, it is apparent that it is advantageous to reduce the particle diameter of the toner or to make the shape of the toner spherical. When the particle size is reduced, the transferability deteriorates, the amount of toner remaining on the electrostatic image carrier increases, and a load is applied to the cleaning process, so that excellent cleaning performance cannot be maintained for a long period of time. On the other hand, when the toner is spherical, in a process having a means for cleaning by contacting the untransferred toner remaining on the electrostatic charge carrier, the toner slips through, and excellent cleaning properties cannot be maintained for a long period of time.
[0010]
Therefore, the present inventors have conducted intensive studies and as a result, in order to solve the above-mentioned problems, at least in a dry toner containing a modified polyester resin, a colorant, and a release agent, the toner is converted into an organic solvent. A dissolved or dispersed product formed by dissolving or dispersing a toner component containing a toner binder component composed of a modified polyester resin capable of reacting with a compound having an active hydrogen group in an aqueous medium containing resin fine particles. An emulsified dispersion obtained by reacting with a compound having a group, and a mixed solution obtained by mixing at least an aqueous solution containing a thickener, by passing through a device for applying a shear force, after the shape of the toner non-spherical, When removing the solvent and washing / desorbing the resin fine particles adhered to the surface to obtain toner particles, the viscosity of the emulsified dispersion and the concentration of the organic solvent are non-spherical particles. It found to be deeply involved in the order, which has led to the completion of the present invention.
[0011]
This is because, in order to deform the particles in which the toner component in the emulsified dispersion is dispersed, the shear energy for deforming the particles is made larger than the internal resistance energy for the particles to recover due to the interfacial tension. (Rugby ball shape). Conversely, if the internal resistance energy is large, the spherical shape is maintained and the cleaning performance is impaired. In addition, if the shear energy is too large, division occurs and fine powder is generated, which causes problems such as filming. It was found that the shear energy was determined by a device that gives the viscosity and shear force of the mixed solution of the emulsified dispersion and the aqueous solution containing the thickener, and that the internal resistance energy was closely related to the concentration of the organic solvent in the mixed solution.
[0012]
That is, according to the present invention, the following (1) to (8) are provided.
(1) A dry toner containing at least a modified polyester resin, a colorant, and a release agent, wherein the toner is a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent. An emulsified dispersion obtained by reacting a dissolved or dispersed product formed by dissolving or dispersing a toner component containing a binder component with a compound having an active hydrogen group in an aqueous medium containing fine resin particles, and at least a thickener Is mixed with an aqueous solution containing the above, and the mixed solution obtained by adjusting the concentration of the organic solvent in the obtained mixed solution to 3 to 15% by weight is passed through a device for applying a shearing force to the mixed solution, whereby the shape of the toner is reduced. A toner for developing an electrostatic image, wherein the toner is obtained by removing the solvent after desphericalization, and washing and desorbing the resin fine particles adhered to the surface.
(2) The electrostatic image developing toner according to (1), wherein the viscosity P of the mixed solution is 2500 to 25000 mPa · s.
(3) The electrostatic image developing toner according to (1) or (2), wherein the toner has a spindle shape.
(4) The spindle shape of the toner has a short axis r ₂ And the major axis r ₁ And the ratio (r ₂ / R ₁ ) Is 0.5 to 0.8 and the thickness r ₃ And the minor axis r ₂ And the ratio (r ₃ / R ₂ ) Is 0.7 to 1.0, the toner for developing an electrostatic image according to the item (3).
(5) A developer containing the toner for developing an electrostatic image according to any one of (1) to (4).
(6) A developing method having a toner recycling mechanism, wherein the toner for developing an electrostatic image according to any one of (1) to (4) is used.
(7) A toner container containing the electrostatic image developing toner according to any one of (1) to (4).
(8) A developing device having a toner recycling mechanism, wherein the electrostatic image developing toner according to any one of (1) to (4) is loaded as a toner.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
(Resin fine particles)
The resin fine particles used in the present invention preferably have a glass transition point (Tg) of 50 to 90 ° C. If the glass transition point (Tg) is less than 50 ° C, the toner storability deteriorates, and In some cases, blocking may occur in the developing machine. When the glass transition point (Tg) exceeds 90 ° C., the resin fine particles may hinder the adhesiveness to the fixing paper, and the fixing lower limit temperature may increase. A more preferred range is 50 to 70 ° C.
The weight average molecular weight is desirably 100,000 or less. Preferably it is 50,000 or less. The lower limit is usually 4000. When the weight average molecular weight exceeds 100,000, the resin fine particles may hinder the adhesiveness to the fixing paper, and the fixing lower limit temperature may be increased.
[0014]
As the resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and a thermoplastic resin or a thermosetting resin may be used.For example, a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, a polyamide resin, and a polyimide Resins, silicon-based resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, polycarbonate resins, and the like. As the resin fine particles, two or more of the above resins may be used in combination. Among these, those comprising a vinyl-based resin, a polyurethane resin, an epoxy resin, a polyester resin or a resin used in combination thereof are preferable because an aqueous dispersion of fine spherical resin particles is easily obtained.
[0015]
The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer, for example, a styrene- (meth) acrylate copolymer, a styrene-butadiene copolymer, and a (meth) acrylate-acrylate copolymer. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.
The average particle size of the resin fine particles is 5 to 200 nm, preferably 20 to 300 nm.
[0016]
(Modified polyester resin capable of reacting with a compound having an active hydrogen group)
A reactive modified polyester resin (RMPE) capable of reacting with a compound having an active hydrogen group (hereinafter, the polyester resin is also simply referred to as polyester) includes, for example, a functional group that reacts with an active hydrogen group such as an incyanate group. Polyester prepolymers and the like. The polyester prepolymer preferably used in the present invention is a polyester prepolymer (A) having an isocyanate group. The isocyanate group-containing polyester prepolymer (A) is produced by reacting a polyester having an active hydrogen group, which is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC), with a polyisocyanate (PIC). . Examples of the active hydrogen group contained in the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Of these, an alcoholic hydroxyl group is preferable.
[0017]
Examples of the polyol include diol (DIO) and tri- or higher valent polyol (TO). DIO alone or a mixture of DIO and a small amount of TO is preferable.
[0018]
Examples of the diol include alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycols (diethylene glycol, triethylene glycol, Dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) An alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the alicyclic diol; Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Of these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols, and alkylene glycols having 2 to 12 carbon atoms. Is a combination of
[0019]
Examples of the trivalent or higher polyol include trihydric or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (trisphenol PA, Phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.
[0020]
Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and tricarboxylic or higher polycarboxylic acid (TC), and DIC alone or a mixture of DIC and a small amount of TC is preferable.
[0021]
Dicarboxylic acids include alkylenedicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.) ). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.
[0022]
Examples of the trivalent or higher polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). As the polycarboxylic acid, the above-mentioned acid anhydride or lower alkyl ester (eg, methyl ester, ethyl ester, isopropyl ester) may be used to react with the polyol.
[0023]
The ratio between the polyol and the polycarboxylic acid is usually 2/1 to 1/1, preferably 1.5 / 1 to 1/1, as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 1, more preferably 1.3 / 1 to 1.02 / 1.
[0024]
Examples of the polyisocyanate (PIC) include aliphatic polyisocyanates (such as tetramethylene diisocyanate, hexamethylene diisocyanate, and 2,6-diisocyanatomethylcaproate); alicyclic polyisocyanates (such as isophorone diisocyanate and cyclohexylmethane diisocyanate); Aromatic diisocyanates (such as tolylene diisocyanate and diphenylmethane diisocyanate); araliphatic diisocyanates (such as α, α, α ′, α′-tetramethylxylylene diisocyanate); isocyanurates; and the above polyisocyanates as phenol derivatives, oximes, caprolactam, etc. And a combination of two or more of these.
[0025]
The ratio of the polyisocyanate is usually 5/1 to 1/1, preferably 4/1 to 1 as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the hydroxyl group-containing polyester. .2 / 1, more preferably 2.5 / 1 to 1.5 / 1. If [NCO] / [OH] exceeds 5, the low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester becomes low, and the hot offset resistance deteriorates.
[0026]
The content of the polyisocyanate (PIC) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If the content is less than 0.5% by weight, the hot offset resistance is deteriorated and the heat storage stability and the low-temperature fixability are both disadvantageous. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.
[0027]
The isocyanate group contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually at least 1, preferably 1.5 to 3 on average, and more preferably 1.8 to 2.5 on average. Individual. If the number is less than one per molecule, the molecular weight of the urea-modified polyester becomes low, and the hot offset resistance deteriorates.
[0028]
The urea-modified polyester-based resin (UMPE) can be obtained from the polyester prepolymer (A) having an isocyanate group by reacting it with the amines (B). This shows an excellent effect as a toner binder.
[0029]
Examples of the amines (B) include diamines (B1), trivalent or higher valent polyamines (B2), amino alcohols (B3), aminomercaptans (B4), amino acids (B5), and those obtained by blocking amino groups of B1 to B5. (B6) and the like. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, etc.); alicyclic diamines (4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diamine Cyclohexane, isophoronediamine, etc.); and aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.).
[0030]
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of the aminomercaptan (B4) include aminoethylmercaptan and aminopropylmercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
[0031]
Examples of the compound (B6) in which the amino group of B1 to B5 is blocked include ketimine compounds and oxazolidine compounds obtained from the amines and ketones (such as acetone, methyl ethyl ketone, and methyl isobutyl ketone) of B1 to B5. Preferred of these amines (B) are B1 and a mixture of B1 and a small amount of B2.
[0032]
Further, the molecular weight of a modified polyester such as a urea-modified polyester can be adjusted by using an elongation terminator, if necessary. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine and the like), and those obtained by blocking them (ketimine compounds).
[0033]
The ratio of the amines (B) is defined as the equivalent ratio [NCO] / [NHx] of the isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and the amino groups [NHx] in the amines (B). , Usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, and more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester becomes low, and the hot offset resistance deteriorates.
[0034]
In the present invention, the polyester modified with a urea bond may contain a urethane bond together with the urea bond. The molar ratio of the urea bond content to the urethane bond content is usually from 100/0 to 10/90, preferably from 80/20 to 20/80, and more preferably from 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance deteriorates.
The amines (B) act as a crosslinking agent or an elongation agent for the modified polyester that can react with the compound having an active hydrogen group.
[0035]
The urea-modified polyester used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester such as the urea modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of a modified polyester such as a urea modified polyester is not particularly limited when an unmodified polyester described later is used, and may be a number average molecular weight that is easily obtained to obtain the weight average molecular weight. In the case of a modified polyester alone such as a urea-modified polyester, the number average molecular weight is usually 20,000 or less, preferably 1,000 to 10,000, and more preferably 2,000 to 8,000. If it exceeds 20,000, the low-temperature fixability and the gloss when used in a full-color device deteriorate.
[0036]
(Unmodified polyester resin)
In the present invention, not only the modified polyester (MPE) such as the polyester modified by the urea bond may be used alone, but also an unmodified polyester (PE) may be contained as a toner binder component. The combined use of PE improves low-temperature fixability and glossiness when used in a full-color device, and is more preferable than single use. Examples of the PE include polycondensates of a polyol and a polycarboxylic acid, which are the same as the polyester component of the MPE. The PE may be modified not only with unmodified polyester but also with a chemical bond other than a urea bond. For example, the PE may be modified with a urethane bond. It is preferable that at least a part of MPE and PE be compatible with each other in view of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the polyester component of the MPE and the PE have similar compositions.
[0037]
When PE is contained, the weight ratio of MPE to PE is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, and particularly preferably 7/93. ２０20/80. When the weight ratio of the MPE is less than 5%, the hot offset resistance is deteriorated, and the heat storage stability and the low-temperature fixability are disadvantageous.
[0038]
The peak molecular weight of PE is generally from 1,000 to 30,000, preferably from 1500 to 10,000, and more preferably from 2,000 to 8,000. If it is less than 1,000, the heat-resistant preservability deteriorates, and if it exceeds 10,000, the low-temperature fixability deteriorates. The hydroxyl value of PE is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of compatibility between heat-resistant storage stability and low-temperature fixability. The acid value of PE is usually 1 to 30, preferably 5 to 20. By having an acid value, it tends to be negatively chargeable.
[0039]
In the present invention, the glass transition point (Tg) of the binder (toner binder) in the toner is usually 50 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 50 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of a modified polyester such as a urea-modified polyester-based resin, the dry toner of the present invention tends to have good heat-resistant storage stability even at a low glass transition point, as compared with known polyester-based toners. The storage elastic modulus of the toner binder was 10,000 dyne / cm at a measurement frequency of 20 Hz. ² (TG ') is usually 100 ° C. or higher, preferably 110 to 200 ° C. If the temperature is lower than 100 ° C., the hot offset resistance deteriorates. As for the viscosity of the toner binder, the temperature (Tη) at which the viscosity becomes 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low-temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or more. It is more preferably at least 10 ° C, particularly preferably at least 20 ° C. The upper limit of the difference is not particularly limited. The difference between Tη and Tg is preferably from 0 to 100 ° C. from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability. The temperature is more preferably from 10 to 90 ° C, particularly preferably from 20 to 80 ° C.
[0040]
(Binder resin)
As a binder resin (toner binder) other than the modified polyester resin, a conventional general material can be mixed and used. Conventionally, as a binder resin used in the production of toner, for example, polyester resin, styrene resin, acrylic resin, epoxy resin, and the like, in a normal toner, among these, from the copolymer of styrene and acrylate Resin is most commonly used. On the other hand, in the low-temperature fixing toner, the polyester resin, which is a resin that easily satisfies the above-described thermal characteristics, has a low softening temperature of the binder resin and a high glass transition point, and thus has a low-temperature fixing property and storage stability. Are better. Further, since the affinity between the polyester resin and the ester bond and the paper is good, a toner having excellent offset resistance can be obtained.
[0041]
The polyester resin used as a main component of the binder resin of the toner for developing an electrostatic image of the present invention is synthesized by a condensation reaction of an acid component and an alcohol component, or a ring opening reaction of a cyclic ester, or a halogen compound. Synthesized by alcohol component and carbon monoxide. In the method for producing a toner for developing an electrostatic charge image of the present invention, in the above-mentioned resin fine particle solution, by polymerizing in combination with the above-mentioned monomer which is a synthetic material of the polyester resin, the above-mentioned excellent physical properties are obtained. The electrostatic image developing toner of the present invention can be easily obtained. Hereinafter, various monomers used as a synthetic material of the polyester resin will be described.
[0042]
First, as the alcohol component and the acid component, those having a valency of 2 or more are suitably used. For example, as the dihydric alcohol, ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1, Diols such as 5-pentanediol and 1,6-hexanediol; bisphenol A, hydrogenated bisphenol A, α, α'-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene, polyoxyethylenated bisphenol A And bisphenol A alkylene oxide adducts, such as polyoxypropylene bisphenol A.
[0043]
Examples of the trihydric or higher alcohol include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,2 5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butaneditriol, trimethylolmethane, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.
[0044]
Examples of the divalent acid include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malon Acids, and other divalent organic acids. Examples of the trivalent acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, and 2,5,7-naphthalenetricarboxylic acid. 1,2,5-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-carboxymethylpropane, tetra (carboxymethyl) methane, 1,2,7 , 8-octanetetracarboxylic acid and the like. Acid anhydrides and acid halides of these organic acids are also preferred acid components in terms of synthesis.
[0045]
As the compound corresponding to the other acid component, a halogen compound can be used. As the halide, a polyhalogen compound is used. For example, cis-1,2-dichloroethene, trans-1,2-dichloroethene, 1,2-dichloropropene, 2,3-dichloropropene, 1,3- Dichloropropene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, o-dibromobenzene, m-dibromobenzene, p-dibromobenzene, o-chlorobromobenzene, dichlorocyclohexane, dichloroethane, 1,4-dichlorobutane , 1,8-dichlorooctane, 1,7-dichlorooctane, dichloromethane, 4,4'-dibromovinylphenol, 1,2,4-tribromobenzene and the like.
[0046]
In the present invention, it is preferable to use, as a synthetic component of the polyester resin, one having at least an aromatic ring in one of the above-mentioned acid component and alcohol component. Further, in the present invention, the total amount of the acid component and the alcohol component, which are synthetic components of the polyester resin, is 1 to 30 parts by weight, preferably 1.5 to 10 parts by weight based on 1 part by weight of the resin fine particles described above. It is preferable to use it so that it is within the range of parts.
[0047]
The use ratio of the acid component to the alcohol component is in the range of 0.9 to 1.5 molar equivalents, preferably 1.0 to 1.3 molar equivalents, for 1 molar equivalent of the carboxyl group. preferable. Here, the carboxyl group includes a halide which is a compound corresponding to the above-mentioned acid component. As another additive, an amine component may be used. Specific examples include triethylamine, trimethylamine, N, N-dimethylaniline and the like. The reaction may be carried out using another condensing agent, for example, dicyclohexylcarbodiimide.
[0048]
(Colorant)
As the colorant used in the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow Iron oxide, loess, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), Pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast Yellow (5G, R), Tartrazine lake, Quinoline yellow lake, Anthrazan yellow BGL, Isoindolinone yellow, Bengala, Lead red, Lead red, Cadmium red, Cadmium mercury red, Antimony red, Permanent red 4R , Para-red, phi-sa-red, parac Luoruto Nitroaniline Red, Risor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlett 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Media, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pi Zolone Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indance Renblue (RS, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithobon and mixtures thereof can be used.
The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.
[0049]
The colorant used in the present invention can be used as a masterbatch combined with a resin. Examples of the binder resin to be manufactured or kneaded with the master batch include, in addition to the above-mentioned modified and unmodified polyester resins, styrene such as polystyrene, poly p-chlorostyrene, and polyvinyl toluene, and polymers of substituted polymers thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α -Methyl chloromethacrylate copolymer Styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination. Wear.
[0050]
This masterbatch can be obtained by mixing and kneading the resin for the masterbatch and the colorant with high shearing force to obtain a masterbatch. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. The so-called flushing method is also known as a method of mixing and kneading an aqueous paste containing water of a coloring agent together with a resin and an organic solvent, transferring the coloring agent to the resin side, and removing water and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high-shear dispersion device such as a three-roll mill is preferably used.
[0051]
(Release agent)
Known release agents can be used as the release agent used in the present invention. For example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long-chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, and the like. Preferred among these are carbonyl group-containing waxes. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 Polyalkanol esters (such as tristearyl trimellitate and distearyl maleate); polyalkanoic acid amides (such as ethylenediamine dibehenylamide); and polyalkylamides (such as trimellitic acid tristearyl amide). And dialkyl ketones (such as distearyl ketone). Preferred among these carbonyl group-containing waxes are polyalkanoic esters. The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat-resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause cold offset at the time of fixing at a low temperature. The melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a value measured at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor improvement effects on hot offset resistance and low-temperature fixability.
The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.
[0052]
(Thickener)
Examples of the thickener include polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyacrylates (alkali metal salts, organic amine salts, quaternary ammonium salts, etc .; weight average molecular weight 3000 to 3,000,000), carboxymethyl cellulose, polyethylene glycol ( Weight average molecular weight of 2,000 to 200,000) and guar gum.
The viscosity of the mixed solution is measured using a B-type viscometer after controlling the temperature in a thermostat at 25 ° C. for 30 minutes.
[0053]
(Charge control agent)
The toner of the present invention may optionally contain a charge control agent. As the charge control agent, any known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkyl amides, simple substances or compounds of phosphorus, tungsten simple substances or compounds, fluorine-based activators, metal salts of salicylic acid, and metal salts of salicylic acid derivatives. Specifically, bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, and E-82 of a salicylic acid metal complex 84, phenolic condensate E-89 (all manufactured by Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (all manufactured by Hodogaya Chemical Industry), quaternary ammonium Salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (all from Hoechst), LRA-901, LR-147 which is a boron complex (Manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, Zone-based pigment, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.
[0054]
In the present invention, the amount of the charge control agent used is determined by the type of the binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the binder resin. Preferably, the range is 0.2 to 5 parts by weight. If the amount exceeds 10 parts by weight, the chargeability of the toner is too large, the effect of the main charge control agent is reduced, the electrostatic attraction with the developing roller increases, the fluidity of the developer decreases, and the image density decreases. Causes a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with the masterbatch and the resin, or may be added when directly dissolving and dispersing in an organic solvent, or may be fixed after toner particles are formed on the toner surface. You may.
[0055]
(External additives)
As the external additive for assisting the fluidity, developability and chargeability of the colored resin particles obtained in the present invention, inorganic fine particles can be preferably used. The primary particle size of the inorganic fine particles is preferably from 5 μm to 2 μm, and particularly preferably from 5 μm to 500 μm. The specific surface area by the BET method is 20 to 500 m. ² / G. The use ratio of the inorganic fine particles is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, and diatomaceous Examples include earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
[0056]
In addition, polymer-based fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polycondensation systems such as silicone, benzoguanamine, and nylon, and methacrylic acid ester and acrylic acid ester copolymers, and thermosetting resins Polymer particles.
[0057]
Such an external additive can be subjected to a surface treatment to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate-based coupling agents, aluminum-based coupling agents, silicone oil, modified silicone oil, and the like are preferable surface treatment agents. .
[0058]
It is preferable to add a cleaning property improving agent for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium. Examples of the cleaning property improving agent include fatty acids such as zinc stearate, calcium stearate, and stearic acid. Metal salts, for example, polymer fine particles produced by soap-free emulsion polymerization of polymethyl methacrylate fine particles, polystyrene fine particles and the like can be mentioned. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.
[0059]
(Production method)
The toner binder can be manufactured by the following method.
Polyol having a hydroxyl group is obtained by heating a polyol and a polycarboxylic acid to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate and dibutyltin oxide and, if necessary, reducing the generated water while reducing the pressure. Get. Next, at 40 to 140 ° C., a polyisocyanate is reacted therewith to obtain a prepolymer (A) having an isocyanate group. Further, this A is reacted with an amine (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When reacting the polyisocyanate and when reacting A and B, a solvent can be used if necessary. Solvents that can be used include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethyl formamide, dimethyl acetamide, etc.) and ethers And the like (e.g., tetrahydrofuran). When a polyester (PE) not modified with a urea bond is used in combination, this PE is produced in the same manner as in the case of the polyester having a hydroxyl group, and this PE is dissolved in a solution after the reaction of the urea-modified polyester, Mix.
[0060]
(Manufacture of toner)
The dry toner of the present invention can be produced by the following method, but is not limited thereto.
[0061]
(Method of manufacturing toner in aqueous medium)
As the aqueous medium, water alone may be used, or a water-miscible solvent may be used in combination. Examples of miscible solvents include alcohols (eg, methanol, isopropanol, ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (eg, methylcellosolve), lower ketones (eg, acetone, methylethylketone), and the like.
[0062]
The toner particles can be formed by reacting a dispersion composed of a prepolymer (A) having an isocyanate group with an amine (B) in an aqueous medium. As a method for stably forming a dispersion comprising a urea-modified polyester or prepolymer (A) in an aqueous medium, a composition of a toner raw material comprising a urea-modified polyester resin or prepolymer (A) in an aqueous medium is used. In addition, a method of dispersing by a shear force and the like can be mentioned. A colorant, a colorant masterbatch, a release agent, a charge control agent, an unmodified polyester resin, and the like, which are the prepolymer (A) and other toner components (hereinafter, referred to as toner raw materials), are dispersed in an aqueous medium. May be mixed at the time of formation, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in an aqueous medium. Further, in the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily need to be mixed when forming particles in an aqueous medium, and after forming the particles. May be added. For example, after forming particles containing no coloring agent, a coloring agent can be added by a known dyeing method.
[0063]
The dispersing method is not particularly limited, but known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferred. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is generally 1,000 to 30,000 rpm, preferably 5,000 to 20,000 rpm. The dispersion time is not particularly limited, but is usually 0.1 to 5 minutes in the case of a batch system. The temperature at the time of dispersion is usually 0 to 150 ° C (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion of the urea-modified polyester or prepolymer (A) has a lower viscosity and is easier to disperse.
[0064]
The amount of the aqueous medium to be used is generally 50 to 2,000 parts by weight, preferably 100 to 1,000 parts by weight, based on 100 parts by weight of the toner component (composition) containing the urea-modified polyester or the prepolymer (A). If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle size cannot be obtained. If it exceeds 20,000 parts by weight, it is not economical. In addition, a dispersant can be used if necessary. The use of a dispersant is preferred because the particle size distribution becomes sharp and the dispersion is stable.
In the step of synthesizing the urea-modified polyester from the prepolymer (A), the amines (B) may be added and reacted before dispersing the toner components in the aqueous medium, or the amines may be dispersed after dispersing in the aqueous medium. The reaction may be caused from the particle interface by adding (B). In this case, urea-modified polyester is preferentially generated on the surface of the toner to be produced, and a concentration gradient can be provided inside the particles.
[0065]
An oily phase in which the toner component is dispersed is emulsified and dispersed in a liquid containing water, as a dispersant for alkylbenzene sulfonate, α-olefin sulfonate, anionic surfactant such as phosphate ester, Amine salt types such as alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride Nonionic surfactants such as quaternary ammonium salt-type cationic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N- Al Le -N, amphoteric surfactants such as N- dimethyl ammonium betaine and the like.
[0066]
Further, by using a surfactant having a fluoroalkyl group, the effect can be improved with a very small amount. Preferred examples of the anionic surfactant having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonylglutamate, and 3- [omega-fluoroalkyl (C6 to C11). ) Oxy] -1-alkyl (C3-C4) sulfonic acid sodium salt, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium salt, fluoroalkyl (C11-C20) carboxylic acid Acid and metal salt, perfluoroalkylcarboxylic acid (C7-C13) and its metal salt, perfluoroalkyl (C4-C12) sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-hydroxyethyl Perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Include,
[0067]
As trade names, Surflon S-111, S-112, S-113 (manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (manufactured by Sumitomo 3M), Unidyne DS-101 , DS-102, (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink and Chemicals), Ektop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204, (manufactured by Tochem Products), Futagent F-100, F150 (manufactured by Neos), and the like.
[0068]
Examples of the cationic surfactant include an aliphatic quaternary ammonium salt such as an aliphatic primary, secondary or secondary amine acid which pertains to a fluoroalkyl group, and a perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt. Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names are Surflon S-121 (manufactured by Asahi Glass Co., Ltd.), Florard FC-135 (manufactured by Sumitomo 3M), Unidine DS-202 (manufactured by Daikin Industries, Ltd.) ), Megafac F-150, F-824 (manufactured by Dainippon Ink and Chemicals), Ectop EF-132 (manufactured by Tochem Products), Futagent F-300 (manufactured by Neos) and the like.
[0069]
Calcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, and the like can also be used as inorganic compound dispersants that are hardly soluble in water.
[0070]
Further, the dispersed droplets may be stabilized by a polymer-based protective colloid. For example, an acid such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, or a (meth) acrylic monomer containing a hydroxyl group Such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylic acid Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerin monoacrylate, glycerin monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of vinyl alcohol and compounds containing a carboxyl group, for example, Vinyl acetate, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having a nitrogen atom or a heterocycle thereof, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester And celluloses such as polyoxyethylene, methylcellulose, hydroxyethylcellulose and hydroxypropylcellulose.
[0071]
In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. I do. In addition, it can be removed by an operation such as decomposition with an enzyme.
[0072]
When a dispersant is used, the dispersant may remain on the surface of the toner particles. However, it is preferable to remove the dispersant by washing after the reaction from the viewpoint of charging the toner.
[0073]
Further, in order to lower the viscosity of the liquid containing the toner component, a solvent in which the urea-modified polyester or the prepolymer (A) is soluble can be used. The use of a solvent is preferred in that the particle size distribution becomes sharp. It is preferable that the solvent is volatile having a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred.
The amount of the solvent to be used relative to 100 parts by weight of the prepolymer (A) is usually 0 to 300 parts by weight, preferably 0 to 100 parts by weight, more preferably 25 to 70 parts by weight. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the reaction.
[0074]
When an amine (B) as a compound having an active hydrogen group is reacted with a modified polyester capable of reacting with a compound having an active hydrogen group, the reaction time depends on the isocyanate group structure of the prepolymer (A) and the amine ( It is selected depending on the reactivity in combination with B), but is usually from 10 minutes to 40 hours, preferably from 2 to 24 hours. The reaction temperature is generally 0-150 ° C, preferably 40-98 ° C. In addition, a known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
[0075]
(Desphering process)
In the present invention, in order to obtain a non-spherical shape, an emulsified dispersion is mixed with a high-viscosity aqueous solution to which a thickener is added, and the mixed solution is subjected to a shearing force by a homomixer, an Ebara milder, or the like. Through which the emulsified particles can be deformed (deformed) by utilizing the difference in viscosity between the oil phase and the aqueous phase in the mixed solution, and thereafter, a step of removing the solvent from the dispersion below the Tg of the binder resin Is provided, the particles are fixed, and a toner having a desired shape can be produced.
As the conditions for deforming the shape, the concentration of the organic solvent, the temperature, the thickener in the aqueous phase, the activator, by adjusting the temperature, by adjusting the viscosity difference between the oil phase and the aqueous phase can be adjusted. I can do it. As the organic solvent, any known organic solvent can be used, but ethyl acetate is particularly preferred.
[0076]
The concentration of the organic solvent is measured by using gas chromatography under the following conditions.

A calibration curve was prepared using n-hexane as a standard substance, and the organic solvent concentration was determined.
[0077]
Examples of the method for adjusting the shearing force include the processing time and the number of times of processing in the apparatus, the temperature and viscosity of the dispersion, and the concentration of the organic solvent in the particles. In addition, the shape of the particles themselves varies depending on the degree of deformation due to shearing force due to differences in the coverage of the organic fine particles on the surface of the particles, elongation and / or degree of crosslinking reaction, and the like, resulting in a difference in the obtained shape.
In the present invention, it is important that the concentration of the organic solvent when applying a shearing force to the mixed solution is 3 to 15% by weight, and particularly preferably 4 to 12% by weight. Further, the viscosity of the mixed solution is preferably 2500 to 25000 mPa · s, particularly preferably 4000 to 20000 mPa · s. Further, the processing temperature is preferably from 20 to 35C.
[0078]
In order to remove the organic solvent from the obtained emulsified dispersion, a method of gradually raising the temperature of the entire system and completely evaporating and removing the organic solvent in the droplets can be adopted. Alternatively, it is also possible to spray the emulsified dispersion in a dry atmosphere, completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and collectively evaporate and remove the aqueous dispersant. . As a drying atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide, combustion gas, or the like, particularly various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Satisfactory target quality can be obtained by short-time treatment such as spray dryer, belt dryer and rotary kiln.
[0079]
The particle size distribution at the time of emulsification dispersion is wide, and when washing and drying are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by cyclone, decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder after drying, but it is preferable to perform the classification operation in a liquid in terms of efficiency. The obtained unnecessary fine particles or coarse particles can be returned to the kneading step again and used for forming particles. At this time, the fine particles or coarse particles may be in a wet state.
[0080]
The dispersant used is preferably removed from the obtained dispersion as much as possible, but is preferably carried out simultaneously with the classification operation described above.
By mixing the resulting dried toner powder with different kinds of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by applying a mechanical impact force to the mixed powder. Immobilization and fusion at the surface can prevent the dissociation of foreign particles from the surface of the resulting composite particles.
[0081]
As specific means, there are a method of applying an impact force to the mixture by a blade rotating at a high speed, a method of throwing the mixture into a high-speed air flow, accelerating, and colliding particles or composite particles with an appropriate collision plate. is there. As the equipment, Angmill (manufactured by Hosokawa Micron), I-type mill (manufactured by Nippon Pneumatic) was modified to reduce the pulverizing air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), Kryptron system (Manufactured by Kawasaki Heavy Industries, Ltd.) and automatic mortars.
[0082]
The non-spherical shape of the toner of the present invention is preferably a spindle shape, and particularly preferably a uniform spindle shape.
An irregular shape or a flat shape in which the toner shape is not constant has poor powder fluidity, and thus has the following problem. Since triboelectric charging cannot be carried out smoothly, problems such as background contamination are likely to occur. When developing minute latent image dots, it is difficult to obtain a dense and uniform toner arrangement, so that dot reproducibility is poor. The electrostatic transfer method is hardly affected by the lines of electric force and the transfer efficiency is poor.
When the toner is close to a true sphere, the powder fluidity is too good and excessively acts on an external force, so that during development and transfer, there is a problem that the toner particles are easily scattered outside the dots. . Further, the spherical toner easily rolls on the photoreceptor, so that there is a problem in that the toner often slips between the photoreceptor and the cleaning member, resulting in poor cleaning.
[0083]
Since the powdery fluidity of the spindle-shaped toner of the present invention is appropriately adjusted, the triboelectric charging is performed smoothly, and the background stain is not generated. Thereafter, the transfer is performed efficiently, and the dot reproducibility is excellent. Further, with respect to the scattering at that time, the powder fluidity applies an appropriate brake to prevent the scattering. The spindle-shaped toner has a limited number of rolling axes as compared with the spherical toner, so that cleaning defects such as sunk under the cleaning member are less likely to occur.
[0084]
The shape of the toner will be described with reference to FIGS.
The spindle-shaped toner of the present invention has a ratio of the short axis to the long axis (r ₂ / R ₁ ) Is 0.5 to 0.8, and the ratio of the thickness to the minor axis (r ₃ / R ₂ ) Is preferably a spindle shape represented by 0.7 to 1.0.
The ratio of the short axis to the long axis (r ₂ / R ₁ If the value of ()) is less than 0.5, the cleaning property is high due to separation from a true spherical shape, but high-quality image cannot be obtained due to poor dot reproducibility and transfer efficiency. On the other hand, the ratio of the short axis to the long axis (r ₂ / R ₁ If) exceeds 0.8, the shape becomes close to a sphere, and in particular, poor cleaning may occur in a low-temperature and low-humidity environment.
Also, the ratio of the thickness to the minor axis (r ₃ / R ₂ ) Is less than 0.7, the shape is close to a flat shape and scattering is small like an irregular toner, but a high transfer rate like a spherical toner cannot be obtained. In particular, the ratio of the thickness to the minor axis (r ₃ / R ₂ ) Is 1.0, the rotating body has a long axis as a rotation axis. By adopting a spindle shape similar to this, the shape is neither irregular nor flat, nor true spherical, all of which have triboelectric charging, dot reproducibility, transfer efficiency, scattering prevention, and cleaning Is satisfied. Note that r ₁ , R ₂ , R ₃ Was measured with a scanning electron microscope (SEM) while changing the angle of the field of view and observing.
[0085]
In the invention, the shape of the toner can be measured by a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).
As a method of measuring toner shape (circularity), an optical detection band method is used in which a suspension containing particles is passed through a detection band on an imaging unit on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. Is appropriate. With this method, the projected area of the particle is obtained. The circularity is a value obtained by dividing the perimeter of an equivalent circle having the same area as the projected area by the perimeter of the actual particle. This value is a value measured as an average circularity by the flow type particle image analyzer FPIA-2100. As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzene sulfonic acid salt, is added as a dispersing agent to 100 to 150 ml of water from which an impure solid substance has been removed in a container, and further measured. Add about 0.1-0.5 g of sample. The suspension in which the sample is dispersed is subjected to a dispersion treatment using an ultrasonic disperser for about 1 to 3 minutes, and the shape of the toner and the shape distribution of the toner are measured by the above-mentioned apparatus with the concentration of the dispersion liquid being 3000 to 10,000 / μl.
[0086]
(Carrier for two components)
When the toner of the present invention is used in a two-component developer, the toner may be used as a mixture with a magnetic carrier. Parts are preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, and magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.
[0087]
The carrier may be coated on the back surface, and examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Further, polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins, polychlorinated resins Halogenated olefin resin such as vinyl, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride And fluoro such as terpolymers of non-fluoride monomers including, and silicone resins.
[0088]
If necessary, a conductive powder or the like may be contained in the coating resin. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance.
[0089]
Further, the toner of the present invention can be used as a one-component magnetic toner without using a carrier or a non-magnetic toner.
[0090]
【Example】
Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto. Parts indicate parts by weight.
[0091]
Example 1
(Synthesis of organic fine particle emulsion)
Production Example 1
683 parts of water, 11 parts of sodium salt of methacrylic acid ethylene oxide adduct sulfate (Eleminor RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid were placed in a reaction vessel equipped with a stir bar and a thermometer. 110 parts of butyl acrylate and 1 part of ammonium persulfate were charged and stirred at 400 rpm for 15 minutes to obtain a white emulsion. The mixture was heated to a temperature in the system of 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% aqueous solution of ammonium persulfate was added, and the mixture was aged at 75 ° C. for 5 hours to give an aqueous solution of a vinyl resin (copolymer of sodium salt of styrene-methacrylic acid-butyl acrylate-ethylene methacrylate ethylene oxide adduct). A dispersion liquid [fine particle dispersion liquid 1] was obtained. The volume average particle diameter of [fine particle dispersion 1] measured with LA-920 was 0.10 μm. A part of [fine particle dispersion 1] was dried to isolate a resin component. The Tg of the resin component was 57 ° C.
[0092]
(Preparation of aqueous phase)
Production Example 2
990 parts of water, 80 parts of [Particle Dispersion 1], 40 parts of a 48.5% aqueous solution of sodium dodecyldiphenyletherdisulfonate (Eleminol MON-7) (manufactured by Sanyo Chemical Industries), and 90 parts of ethyl acetate are mixed and stirred, and milky white is stirred. A liquid was obtained. This is designated as [aqueous phase 1].
[0093]
(Synthesis of low molecular polyester)
Production Example 3
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen inlet pipe, 220 parts of bisphenol A ethylene oxide 2 mol adduct, 561 parts of bisphenol A propylene oxide 3 mol adduct, 218 parts of terephthalic acid, 48 parts of adipic acid and dibutyltin After adding 2 parts of oxide and reacting at 230 ° C. for 8 hours at normal pressure, and further reacting for 5 hours at a reduced pressure of 10 to 15 mmHg, 45 parts of trimellitic anhydride is added to the reaction vessel, and 2 hours at 180 ° C. and normal pressure. The reaction was performed to obtain [Low molecular polyester 1]. [Low-molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6,700, a Tg of 43 ° C, and an acid value of 25.
[0094]
(Synthesis of prepolymer)
Production Example 4
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrite introduction pipe, 682 parts of bisphenol A ethylene oxide 2 mol adduct, 81 parts of bisphenol A propylene oxide 2 mol adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride Then, 2 parts of dibutyltin oxide was added, reacted at normal pressure of 230 ° C. for 8 hours, and further reacted at a reduced pressure of 10 to 15 mmHg for 5 hours to obtain [intermediate polyester 1]. [Intermediate polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 49.
Next, 411 parts of [intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. 1]. The free isocyanate weight% of [Prepolymer 1] was 1.53%.
[0095]
(Synthesis of ketimine)
Production Example 5
170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stir bar and a thermometer, and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.
[0096]
(Synthesis of master batch)
Production Example 6
Carbon black (Regal 400R, manufactured by Cabot Corporation): 40 parts, binder resin: polyester resin (Sanyo Chemical RS-801, acid value 10, Mw 20,000, Tg 64 ° C): 60 parts, water: 30 parts were mixed with a Henschel mixer, A mixture in which water was soaked in the pigment aggregate was obtained. This was kneaded with two rolls set at a roll surface temperature of 130 ° C. for 45 minutes and pulverized to a size of 1 mmφ with a pulverizer to obtain [Master Batch 1].
[0097]
(Creation of oil phase)
Production Example 7
378 parts of [low-molecular polyester 1], 110 parts of carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: manufactured by Orient Chemical Industries), and 947 parts of ethyl acetate are charged into a container in which a stirring bar and a thermometer are set, and stirred. The temperature was raised to 80 ° C., kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged into the container and mixed for 1 hour to obtain [raw material solution 1].
[Material Dissolution 1] 1324 parts was transferred to a container, and a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.) was used to feed the liquid at a rate of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads at 80% by volume. Under the conditions of filling and three passes, carbon black and WAX were dispersed. Next, 1324 parts of a 65% ethyl acetate solution of [low-molecular polyester 1] was added, and the mixture was passed once with a bead mill under the above conditions to obtain [pigment / WAX dispersion liquid 1]. The solid content concentration (130 ° C., 30 minutes) of [Pigment / WAX dispersion liquid 1] was 50%.
[0098]
(Emulsification)
Production Example 8
[Pigment / WAX Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 6.6 parts are placed in a container, and are mixed with a TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 1 minute. After mixing, 1200 parts of [aqueous phase 1] was added to the container, and the mixture was mixed with a TK homomixer at 13,000 rpm for 20 minutes to obtain [emulsified slurry 1].
[0099]
(Deformed)
Production Example 9
1365 parts of ion-exchanged water and 35 parts of carboxymethylcellulose (CMC Daicel-1280: manufactured by Daicel Chemical Industries, Ltd.) were mixed in a container and stirred with 1000 parts of [Emulsified Slurry 1] in an aqueous solution. K. Pipeline homomixer model: PL-2V (manufactured by Tokushu Kika) was passed at 2,000 rpm at a flow rate of 1000 g / min to obtain [deformed slurry 1]. At this time, the viscosity of the deformed slurry 1 was 4000 mPa · s.
[0100]
(Desolvation)
Production Example 10
[Deformed slurry 1] was charged into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours, followed by aging at 45 ° C. for 4 hours to obtain [dispersed slurry 1].
[0101]
(Washing → drying)
[Dispersion Slurry 1] After 100 parts of filtered under reduced pressure,
{Circle around (1)} 100 parts of ion-exchanged water were added to the filter cake, mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered.
{Circle around (2)}: 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of <1>, and the mixture was subjected to ultrasonic vibration, mixed with a TK homomixer (at 12,000 rpm for 30 minutes), and then filtered under reduced pressure. . This ultrasonic alkali cleaning was performed again (ultrasonic alkali cleaning twice).
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered twice to obtain [Filter cake 1]. Was.
[Filter cake 1] was dried at 45 ° C. for 48 hours using a circulating drier, and sieved with a mesh having a mesh size of 75 μm to obtain [Toner matrix 1].
[0102]
Comparative Example 1
T. of Example 1 K. [Toner matrix 5] was obtained in the same manner as in Example 1 except that the flow was not performed at 2,000 rpm and at a flow rate of 1000 g / min using a pipeline homomixer model: PL-2V (manufactured by Tokushu Kika).
[0103]
Examples 2 to 4, Comparative Examples 2 to 4
Except that the viscosity P and the concentration of the organic solvent in Example 1 (Production Example 9) were changed as shown in Table 1 by changing the concentrations of the thickener and the ion-exchanged water, and the viscosity of the deformed slurry was adjusted as shown in Table 1. In the same manner as in Example 1, [Toner bases 2 to 4 and 6 to 8] were obtained.
[0104]
(Measurement of shape)
The non-spherical shape was determined by using an optical microscope with a true spherical shape as rank 1 as shown in the photograph of FIG. 6, a substantially spherical shape as rank 2 as in the photo of FIG. 5, and a rank 2 as in the photo of FIG. Spindle-shaped (rugby ball) and half-spherical balls are ranked as Rank 3, Spindle-shaped but irregular as shown in the photo of Fig. 3, Rank 4, and Spindle-shaped and uniform as in the photo of Fig. 2. 5 and the shape was ranked and judged. In the present invention, non-spherical ones are those having a rank of 3 or more.
In order to maintain the cleaning property over a long period, it is effective that the number of particles having a shape rank of 4 or more and a circle-equivalent diameter of less than 2.0 μm on a number basis measured by a flow type particle image analyzer is less than 25% by number. Particles having an equivalent circle diameter of less than 2.0 μm can be measured using a flow type particle image analyzer FPIA-1000 manufactured by SYSMEX CORPORATION. The outline of the apparatus and the measurement is described in JP-A-8-136439. The measurement is performed by adjusting a 1% NaCl aqueous solution using primary sodium chloride and then adding 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, as a dispersant to 50 to 100 ml of a 0.45 μm-filtered liquid. In addition, add 1-10 mg of sample. This was subjected to a dispersion treatment for 1 minute by an ultrasonic disperser, and the measurement was performed using a dispersion liquid in which the particle concentration was adjusted to 5000 to 15000 particles / μl. The number of particles is measured by calculating the diameter of a circle having the same area as a two-dimensional image area picked up by a CCD camera as a circle equivalent diameter. Based on the accuracy of the CCD pixels, measurement data of particles was obtained with a circle equivalent diameter of 0.6 μm or more effective.
Table 1 shows the rank of the shape of each toner base.
[0105]
[Table 1]

[0106]
To 100 parts of each of the toner bases 1 to 8 obtained as described above, 0.7 parts of hydrophobic silica and 0.3 parts of hydrophobic titanium oxide were mixed with a Henschel mixer.
[0107]
A developer comprising 5% by weight of each toner treated with an external additive and 95% by weight of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm is prepared, and 45 sheets of A4 size paper are printed per minute. Using imagio Neo 450 manufactured by Ricoh, continuous printing was performed and evaluated by the following methods and criteria. The results are shown in Table 2.
[0108]
[Evaluation method and evaluation criteria]
(Cleanability)
The transfer residual toner on the photoreceptor that has passed through the cleaning process is transferred to a blank sheet of paper using a scotch tape (manufactured by Sumitomo 3M Limited) and measured with a Macbeth reflection densitometer RD514, and the difference from the blank is 0.01 or less. The samples were evaluated as ○ (good), and those exceeding them were evaluated as × (poor).
[0109]
(Filming resistance)
The occurrence of toner filming on the developing roller or the photosensitive member was observed. ○ indicates no filming, △ indicates filming on the streaks, and × indicates that filming is present as a whole.
[0110]
[Table 2]

[0111]
【The invention's effect】
According to the present invention, it is possible to provide a toner for developing an electrostatic image that is excellent in filming resistance and cleaning properties for a long time and is compatible with a low-temperature fixing system. Further, according to the present invention, a developer using the toner, a developing method, a toner container filled with the toner, and a developing device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a toner shape.
FIG. 2 is a photograph using an optical microscope of a toner to show a toner base shape having rank 5 (uniform spindle shape).
FIG. 3 is a photograph using an optical microscope of a toner to show a toner base shape having rank 4 (irregular spindle shape).
FIG. 4 is a photograph using an optical microscope of a toner to show a toner base shape having a rank of 3 (a spindle shape and a spherical shape are about half).
FIG. 5 is a photograph using an optical microscope of the toner to show a toner having a rank 2 (substantially spherical) in the base form of the toner.
FIG. 6 is a photograph using an optical microscope of a toner to show a toner having a rank 1 (true sphere) in a base form of the toner.
[Explanation of symbols]
r ₁ Long axis of toner
r ₂ Short axis of toner
r ₃ Toner thickness

Claims (8)

A dry toner containing at least a modified polyester resin, a colorant, and a release agent, wherein the toner comprises a toner binder component comprising a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent. Containing an emulsified dispersion obtained by reacting a dissolved or dispersed product formed by dissolving or dispersing a toner composition containing a compound having an active hydrogen group in an aqueous medium containing resin fine particles, and at least a thickener An aqueous solution is mixed, and the mixed solution obtained by adjusting the concentration of the organic solvent in the obtained mixed solution to 3 to 15% by weight is passed through a device for applying a shear force to the mixed solution to make the shape of the toner non-spherical. And then removing the solvent, and washing and desorbing the resin fine particles adhering to the surface. The toner according to claim 1, wherein the viscosity P of the mixed solution is 2500 to 25000 mPa · s. The toner according to claim 1, wherein the toner has a spindle shape. The toner of the spindle shape, the ratio of the minor axis _{r 2} and the major axis _{r 1 (r 2 / r 1} ) is 0.5 to 0.8, the ratio between the thickness _{r 3} and the minor axis _{r 2} (r ₃ / r ₂ ) is 0.7 to 1.0, and the electrostatic image developing toner according to claim 3, wherein A developer comprising the electrostatic image developing toner according to claim 1. A developing method having a toner recycling mechanism, wherein the electrostatic image developing toner according to claim 1 is used. A toner container containing the toner for developing an electrostatic image according to claim 1. 5. A developing device comprising a toner recycling mechanism and loaded with the toner for developing an electrostatic image according to claim 1.

Images