JP4084666B2 - Toner for electrostatic image development - Google Patents

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]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic image developing toner, a developer, a developing method, a toner container, and a developing device for developing an electrostatic image formed on the surface of a photoreceptor in electrophotography and electrostatic recording.
[0002]
[Prior art]
Conventionally, in an electrophotographic apparatus, an electrostatic recording apparatus, or the like, an electric or magnetic latent image is visualized with toner. For example, in electrophotography, an electrostatic charge image (latent image) is formed on a photoreceptor, and then the latent image is developed with toner to form a toner image. The toner image is usually transferred onto a transfer material such as paper and then fixed by a method such as heating. Toner used for electrostatic image development is generally colored particles in which a binder, a colorant, a charge control agent, and other additives are contained in a binder resin. There is a suspension polymerization method. In the pulverization method, a colorant, a charge control agent, an offset preventing agent and the like are melt-mixed in a thermoplastic resin and uniformly dispersed, and the resulting composition is pulverized and classified to produce a toner. According to the pulverization method, a toner having some excellent characteristics can be produced, but there is a limitation in the selection of the toner material. For example, the composition obtained by melt mixing must be capable of being pulverized and classified by economically usable equipment. From this requirement, the melt-mixed composition must be made sufficiently brittle. For this reason, when the above composition is actually pulverized into particles, a wide range of particle size distribution is likely to be formed, and when attempting to obtain a copy image with good resolution and gradation, for example, a particle size of 5 μm The following fine powder and coarse powder of 20 μm or more must be removed by classification, which has the disadvantage that the yield becomes very low. Further, in the pulverization method, it is difficult to uniformly disperse the colorant, the charge control agent, and the like in the thermoplastic resin. The uneven dispersion of the compounding agent adversely affects the fluidity, developability, durability, image quality and the like of the toner.
[0003]
In recent years, in order to overcome these problems in the pulverization method, a toner production method 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 drawback of poor cleaning properties. The most important problem is that it is difficult to completely remove the transfer residual toner on the surface of the image bearing member by a cleaning means, resulting in poor cleaning. In particular, in the blade cleaning method, the toner is close to the closest packed state between the contact portions of the image carrier and the cleaning blade at the time of cleaning, and the first layer toner having a strong adhesion to the image carrier and the next layer toner. The toner slips between the second-layer toner and the first-layer toner remains on the image carrier as a defective cleaning.
[0004]
In order to solve such problems, the following proposals 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 the surface of an image carrier and residual toner on the surface of the image carrier is removed, a conductive member is used for the cleaning blade, and an AC bias voltage and a toner at the time of development are used. 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 that cleans the surface of a photoreceptor by scraping off residual toner on the photoreceptor after transfer with the 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, any of the methods described in the publications has a cleaning action by contacting the cleaning blade with the 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 oozes out to the surface by the pressure and is rubbed against the image carrier. In addition, the charging roller that contacts and charges the photosensitive member is contaminated, and the original charging ability cannot be exhibited. Further, although improvement can be considered by devising an external additive for the toner, sufficient cleaning properties could not be obtained.
[0006]
In addition, a method has been proposed in which resin fine particles obtained by an emulsion polymerization method are associated to obtain irregular toner particles. However, this method has the following problems. When releasing agent fine particles are associated with each other in order 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. . Resin fine particles, release agent fine particles, colorant fine particles, etc. are randomly fused to constitute toner particles, so there is a variation in composition (content ratio of constituent components) and molecular weight of constituent resins among the obtained toner particles. As a result, the toner particles have different surface characteristics, and a stable image cannot be formed over a long period of time. Further, in a low-temperature fixing system requiring low-temperature fixing, fixing inhibition occurs due to resin fine particles unevenly distributed on the toner surface, and a fixing temperature range cannot be secured.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-265360 [Patent Document 2]
Japanese Patent Laid-Open No. 7-210053
[Problems to be solved by the invention]
The present invention has been made based on the above situation.
A first object of the present invention is to provide a toner for developing an electrostatic charge 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, a developing method, a toner container and a developing device using the toner.
[0009]
[Means for Solving the Problems]
In order to obtain a high-resolution and high-quality image in general, it is obvious that it is advantageous to reduce the toner particle diameter or to make the shape spherical. When the particle size is reduced, the transferability is deteriorated and the amount of toner remaining on the electrostatic image bearing member is increased, which imposes a load on the cleaning process, and the excellent cleaning property cannot be maintained over a long period of time. On the other hand, when the toner is spherical, in a process having a means for cleaning by abutting the untransferred toner remaining on the electrostatic charge bearing member, the toner slips out, and excellent cleaning properties cannot be maintained for a long time.
[0010]
Accordingly, as a result of intensive studies, the present inventors have solved at least the dry polyester toner containing a modified polyester resin, a colorant, and a release agent in order to solve the above problems. A solution or dispersion formed by dissolving or dispersing a toner composition containing a toner binder component composed of a modified polyester resin capable of reacting with a compound having an active hydrogen group therein is dissolved in an aqueous medium containing resin fine particles. After the emulsion dispersion obtained by reacting with the group-containing compound and the aqueous solution containing at least a thickener is passed through a device that applies a shearing force, the toner is non-spherical, When toner particles are obtained by removing the solvent and washing and desorbing the resin fine particles adhering to the surface, particles having a non-spherical viscosity and organic solvent concentration of the emulsified dispersion are obtained. It found to be deeply involved in the order, which has led to the completion of the present invention.
[0011]
In order to deform the particles in which the toner composition in the emulsified dispersion is deformed, the spindle energy is increased by increasing the shear energy that deforms the particles rather than the internal resistance energy that the particles attempt to recover due to the interfacial tension. It can be transformed into a shape (rugby ball shape). On the other hand, when the internal resistance energy is large, the spherical shape is maintained and the cleaning property is hindered. On the other hand, if the shear energy is too large, splitting occurs and fine powder is generated, which causes problems such as filming. It was found that the shear energy is a device that gives the viscosity and shear force of a mixed solution of an aqueous solution containing an emulsified dispersion and a thickener, and the internal resistance energy is 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 comprises 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 solution or dispersion 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 resin fine particles, and at least a thickener Is mixed with an aqueous solution containing a solution, and the mixed solution obtained by adjusting the organic solvent concentration of the obtained mixed solution to 3 to 15% by weight is passed through a device that applies a shearing force to the mixed solution. A toner for developing an electrostatic charge image, which is obtained by removing the solvent after being made non-spherical and washing and desorbing the resin fine particles adhering to the surface.
(2) The electrostatic charge image developing toner according to (1), wherein the mixed solution has a viscosity P of 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 ratio (r ₂ / r ₁ ) between the minor axis r ₂ and the major axis r ₁ of 0.5 to 0.8, and a thickness r ₃ and a minor axis r ₂ . The toner for developing electrostatic images according to (3) above, wherein the ratio (r ₃ / r ₂ ) is 0.7 to 1.0.
(5) A developer comprising the electrostatic image developing toner according to any one of (1) to (4).
(6) A developing method having a toner recycling mechanism, wherein the electrostatic image developing toner according to any one of (1) to (4) is used.
(7) A toner container comprising the electrostatic image developing toner according to any one of (1) to (4).
(8) A developing device having a toner recycling mechanism and loaded with the electrostatic image developing toner according to any one of (1) to (4) as a toner.
[0013]
DETAILED DESCRIPTION OF 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. When the glass transition point (Tg) is less than 50 ° C., the toner storage stability is deteriorated and stored. Sometimes, blocking may occur in the developing machine. When the glass transition point (Tg) is higher than 90 ° C., the resin fine particles may inhibit the adhesion to the fixing paper, and the minimum fixing 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 inhibit the adhesion with the fixing paper, and the minimum fixing temperature may increase.
[0014]
The resin fine particles may be any resin as long as it can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide Examples thereof include resins, silicon-based resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, two or more of the above resins may be used in combination. Among these, those made of a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, or a combination resin thereof are preferable because an aqueous dispersion of fine spherical resin particles is easily obtained.
[0015]
Vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester copolymers. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.
In the resin fine particles, the average particle diameter is 5 to 200 nm, preferably 20 to 300 nm.
[0016]
(Modified polyester resin capable of reacting with compounds having active hydrogen groups)
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) has, for example, a functional group that reacts with an active hydrogen group such as an isocyanate group. And polyester prepolymers having the same. The polyester prepolymer preferably used in the present invention is a polyester prepolymer (A) having an isocyanate group. The polyester prepolymer (A) having an isocyanate group is produced by reacting a polyester having an active hydrogen group with a polyisocyanate (PIC), which is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC). . Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.
[0017]
Examples of the polyol include diol (DIO) and trivalent or higher polyol (TO), and DIO alone or a mixture of DIO and a small amount of TO is preferable.
[0018]
Examples of the diol include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (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.) ); Adducts of alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) of the above alicyclic diols; Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, 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. It is a combined use.
[0019]
Examples of the trihydric or higher polyol include 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (trisphenol PA, Phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols.
[0020]
Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and trivalent 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 alkylene dicarboxylic 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.) ) And the like. 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 valent polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid, you may make it react with a polyol using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.
[0023]
The ratio of 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]
As polyisocyanate (PIC), aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanate (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; 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 an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. .2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate.
[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 it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.
[0027]
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is a piece. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.
[0028]
From the polyester prepolymer (A) having an isocyanate group, a urea-modified polyester resin (UMPE) can be obtained by reacting this with an amine (B). This exhibits an excellent effect as a toner binder.
[0029]
As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino groups B1 to B5 blocked (B6).
Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diamines). Cyclohexane, isophoronediamine, etc.); and aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
[0030]
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
[0031]
Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.
[0032]
Furthermore, if necessary, the molecular weight of a modified polyester such as urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
[0033]
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, 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 is lowered, and the hot offset resistance is deteriorated.
[0034]
In the present invention, the polyester modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.
The amines (B) act as a crosslinking agent or an extender for the modified polyester that can react with a 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 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 urea-modified polyester is not particularly limited when an unmodified polyester described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. In the case of a modified polyester alone such as urea-modified polyester, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.
[0036]
(Unmodified polyester resin)
In the present invention, not only a modified polyester (MPE) such as a polyester modified with a urea bond, but also a polyester (PE) which is not modified can be contained as a toner binder component. The combined use of PE improves low-temperature fixability and gloss when used in a full-color device, and is preferable to single use. Examples of PE include polycondensates of polyols and polycarboxylic acids similar to those of the polyester component of MPE, and preferred ones are also the same as MPE. In addition, PE may be modified with a chemical bond other than an unmodified polyester, and may be modified with a urethane bond, for example. It is preferable that MPE and PE are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Therefore, a similar composition is preferable for the polyester component of MPE and PE.
[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. ~ 20/80. If the weight ratio of MPE is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
[0038]
The peak molecular weight of PE is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. 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 both heat-resistant storage stability and low-temperature fixability. The acid value of PE is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.
[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 it is less than 50 ° C., the heat resistant storage stability of the toner is deteriorated, 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 resin, the dry toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester toners. As the storage elastic modulus of the toner binder, the temperature (TG ′) at which 10000 dyne / cm ² is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the toner binder, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or lower, 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. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.
[0040]
(Binder resin)
In addition to the modified polyester resin, a conventional general material can be mixed and used as a binder resin (toner binder). Conventionally, binder resins used for toner production include, for example, polyester resins, styrene resins, acrylic resins, epoxy resins, and the like. In ordinary toners, among these, copolymers of styrene and acrylate esters are used. The most commonly used resin. On the other hand, in the low-temperature fixing toner, the polyester resin, which is a resin that easily satisfies the thermal characteristics as described above, has a low softening temperature and a high glass transition point. Are better. Further, since the affinity between the ester bond of the polyester resin and the paper is good, the toner has excellent offset resistance.
[0041]
The polyester resin used as the main component of the binder resin of the toner for developing an electrostatic charge 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 and Synthesized with alcohol component and carbon monoxide. In the method for producing a toner for developing an electrostatic charge image of the present invention, the above-mentioned excellent physical properties are obtained by polymerizing a combination of the above-mentioned monomers serving as a polyester resin synthetic material in the above-mentioned resin fine particle solution. The toner for developing an electrostatic charge image of the present invention can be easily obtained. Hereinafter, various monomers used as a synthetic material for the polyester resin will be described.
[0042]
First, as the alcohol component and the acid component, those having a valence of 2 or more are preferably used. For example, as the divalent 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 Bisphenol A alkylene oxide adducts such as polyoxypropylenated bisphenol A and the like.
[0043]
Examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, sucrose, 1,2,4-butanetriol, 1,2, 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 Examples include 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. Acid anhydrides and acid halides of these organic acids are also preferred acid components for 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 a polyester resin that has at least an aromatic ring in one of the acid component and alcohol component listed above. 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 in the range of parts.
[0047]
The ratio of the acid component to the alcohol component is 0.9 to 1.5 molar equivalents, preferably 1.0 to 1.3 molar equivalents of alcohol groups per 1 molar equivalent of carboxyl groups. preferable. The carboxyl group here includes halides which are compounds corresponding to the acid components listed above. As other additives, an amine component may be used. Specific examples include triethylamine, trimethylamine, N, N-dimethylaniline and the like. Moreover, you may react using another condensing agent, for example, dicyclohexyl carbodiimide etc.
[0048]
(Coloring agent)
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, ocher, yellow lead, 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, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R , Para red, phissa red, parac Luort Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pi Zoron Red, Polyazo Red, Chrome Vermilion, 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 Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Gree Lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon 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 also be used as a master batch combined with a resin. As the binder resin kneaded with the masterbatch production or masterbatch, in addition to the above-mentioned modified and unmodified polyester resins, styrene such as polystyrene, poly p-chlorostyrene and polyvinyltoluene, and polymers of substituted products thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Polymer, 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-malein 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. wear.
[0050]
The master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture 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)
As the release agent used in the present invention, known ones can be used. For example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sazol wax, etc.); carbonyl group-containing wax, etc. may be mentioned. Of these, carbonyl group-containing waxes are preferred. 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. -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylene diamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. 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 a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving 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)
As the thickener, polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyacrylate (alkali metal salt, organic amine salt, quaternary ammonium salt, etc .; weight average molecular weight 3000 to 3000000), carboxymethyl cellulose, polyethylene glycol ( Weight average molecular weight 2000-200000) and guar gum.
The viscosity of the mixed solution is measured using a B-type viscometer after the temperature is adjusted for 30 minutes in a constant temperature layer at 25 ° C.
[0053]
(Charge control agent)
The toner of the present invention may contain a charge control agent as necessary. All known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge NEG VP2036 of quaternary ammonium salt, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (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 charge control agent used is determined uniquely by the type of 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 with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, and of course, they can be added directly when dissolved and dispersed in an organic solvent. May be.
[0055]
(External additive)
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 diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used 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, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
[0056]
Other polymer fine particles such as polystyrene, methacrylic acid ester and acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polycondensation systems such as silicone, benzoguanamine, and nylon, and thermosetting resins Examples include polymer particles.
[0057]
Such external additives can be surface treated 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 fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
[0058]
It is preferable to incorporate a cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium. Examples of the cleaning property improver include fatty acids such as zinc stearate, calcium stearate, and stearic acid. Mention may be made, for example, of polymer salts produced by soap-free emulsion polymerization of metal salts such as polymethyl methacrylate fine particles and polystyrene fine particles. 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 produced by the following method.
Polyester having a hydroxyl group by heating the polyol and polycarboxylic acid to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxy titanate, dibutyltin oxide, etc., and distilling off the water generated while reducing the pressure as necessary. Get. Next, this is reacted with polyisocyanate at 40 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, this A is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When the polyisocyanate is reacted and when A and B are reacted, a solvent can be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to polyisocyanates (PIC) such as tetrahydrofuran (such as tetrahydrofuran). When using a polyester (PE) not modified with a urea bond, this PE is produced in the same manner as in the case of a polyester having a hydroxyl group, and this is dissolved in a solution after completion of 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]
(Toner production method in aqueous medium)
As an aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), 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, the composition of the toner raw material comprising a urea-modified polyester resin or prepolymer (A) in the aqueous medium is used. In addition, a method of dispersing by shearing force may be mentioned. Colorant, colorant masterbatch, release agent, charge control agent, unmodified polyester resin, etc., which are prepolymer (A) and other toner components (hereinafter referred to as toner raw materials) are dispersed in an aqueous medium. It is preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.
[0063]
The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, 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 preferable. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during 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 low viscosity and is easy to disperse.
[0064]
The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts by weight of the toner composition (composition) containing urea-modified polyester and prepolymer (A). If the amount is less than 50 parts by weight, the dispersed state of the toner composition is poor and toner particles having a predetermined particle size cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant 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 the toner composition is dispersed in the aqueous medium, or the amines may be reacted after being dispersed in the aqueous medium. (B) may be added to cause a reaction from the particle interface. 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]
As a dispersant for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water, an anionic surfactant such as alkylbenzene sulfonate, α-olefin sulfonate, and phosphate ester, Amine salt types such as alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, 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 obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, 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. Can be mentioned,
[0067]
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), Mega-Fac F-l0, F-l20, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).
[0068]
In addition, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C 6 -C 10) sulfonamidopropyltrimethylammonium salt which right the fluoroalkyl group, Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries, Ltd.) ), Megafuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.) and the like.
[0069]
Moreover, calcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as an inorganic compound dispersant that is hardly soluble in water.
[0070]
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol 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, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as 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 heterocyclic ring 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 Polyoxyethylenes such as, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.
[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 then washing with water. To do. It can also be removed by operations such as enzymatic degradation.
[0072]
When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner to wash away after the reaction.
[0073]
Further, in order to lower the viscosity of the liquid containing the toner composition, a solvent in which the urea-modified polyester or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with 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 preferable.
The usage-amount of the solvent with respect to 100 weight part of prepolymers (A) is 0-300 weight part normally, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the reaction.
[0074]
When the 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 is determined by the isocyanate group structure and amines (prepolymer (A)) Although it is selected depending on the reactivity due to the combination with B), it is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is usually 0 to 150 ° C., preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
[0075]
(Non-sphericalization 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 this mixed solution is subjected to a shearing force by a homomixer, Ebara milder, or the like. The emulsion particles can be deformed (deformed) by utilizing the difference in viscosity between the oil phase and the aqueous phase in the mixed solution, and then the solvent is removed from the dispersion below the Tg of the binder resin. By providing the toner particles, the toner having a desired shape can be produced by fixing the particles.
Conditions for deforming the shape can be adjusted by adjusting the viscosity difference between the oil phase and the aqueous phase by adjusting the concentration of organic solvent, temperature, thickener in the aqueous phase, activator, and temperature. I can do it. As the organic solvent, any conventionally known organic solvent can be used, but ethyl acetate is particularly preferable.
[0076]
The organic solvent concentration is measured using gas chromatography under the following conditions.

A calibration curve was prepared using n-hexane as the standard substance, and the organic solvent concentration was determined.
[0077]
Examples of the method for adjusting the shearing force include the processing time and number of processing of the apparatus, the temperature and viscosity of the dispersion, the concentration of the organic solvent in the particles, and the like. In addition, the shape of the particles themselves varies depending on the degree of deformation due to the shearing force due to differences in the coverage of organic fine particles on the particle surface, elongation, and / or the degree of crosslinking reaction.
In the present invention, the concentration of the organic solvent when a shearing force is applied to the mixed solution is important to be 3 to 15% by weight, and particularly preferably 4 to 12% by weight. Furthermore, the viscosity of the mixed solution is preferably 2500 to 25000 mPa · s, and particularly preferably 4000 to 20000 mPa · s. Furthermore, the processing temperature is preferably 20 to 35 ° C.
[0078]
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.
[0079]
When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes 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 a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
[0080]
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.
By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent detachment of the foreign particles from the surface of the resulting composite particle.
[0081]
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) is modified to reduce the grinding air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron system (Made by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.
[0082]
The non-spherical shape of the toner of the present invention is preferably a spindle shape, particularly preferably a uniform spindle shape.
An irregular shape or a flat shape with a non-constant toner shape has the following problems because the powder fluidity is poor. Since frictional charging cannot be performed smoothly, problems such as background stains are likely to occur. When developing a minute latent image dot, the dot reproducibility is inferior because it is difficult to obtain a dense and uniform toner arrangement. In the electrostatic transfer method, the transfer efficiency is inferior due to being hardly affected by the lines of electric force.
When the toner is close to a true sphere, the powder fluidity is too good and excessively acts on the external force, so that there is a problem that the toner particles are likely to be scattered outside the dots during development and transfer. . Further, since the spherical toner easily rolls on the photoreceptor, there is a problem that the toner often gets into the gap between the photoreceptor and the cleaning member, resulting in poor cleaning.
[0083]
In the spindle-shaped toner of the present invention, the powder fluidity is appropriately adjusted, so that the triboelectric charging is smoothly performed and the background stain is not generated, and the minute latent image dots are developed in an orderly manner. After that, it is efficiently transferred and has excellent dot reproducibility. Further, the powder flowability is moderately braked to prevent scattering at that time. The spindle-shaped toner has a limited rolling axis as compared with the spherical toner, and therefore, it is difficult to cause a cleaning defect such as to sink under the cleaning member.
[0084]
The toner shape will be described with reference to FIGS.
The spindle-shaped toner of the present invention has a minor axis / major axis ratio (r ₂ / r ₁ ) of 0.5 to 0.8 and a thickness / minor axis ratio (r ₃ / r ₂ ) of 0. It is preferably a spindle shape represented by .7 to 1.0.
When the ratio of the minor axis to the major axis (r ₂ / r ₁ ) is less than 0.5, the separation from the true spherical shape is high, but the cleaning property is high, but the dot reproducibility and transfer efficiency are inferior, resulting in high quality image quality. It can no longer be obtained. On the other hand, when the ratio of the minor axis to the major axis (r ₂ / r ₁ ) exceeds 0.8, it becomes close to a sphere, and cleaning failure may occur particularly in a low temperature and low humidity environment.
Further, when the ratio of thickness to minor axis (r ₃ / r ₂ ) is less than 0.7, it is close to a flat shape and less scattered like an amorphous toner, but a high transfer rate like a spherical toner can be obtained. Absent. In particular, when the ratio of the thickness to the short axis (r ₃ / r ₂ ) is 1.0, the rotating body has the long axis as the rotation axis. By making the spindle shape close to this, it is a shape that is neither an irregular shape, a flat shape nor a spherical shape, and all of the triboelectric chargeability, dot reproducibility, transfer efficiency, anti-scattering properties, and cleaning properties that both shapes have It will be a shape that satisfies.
Note that r ₁ , r ₂ , and r ₃ were measured with a scanning electron microscope (SEM) while taking and observing photographs while changing the viewing angle.
[0085]
In the present invention, the toner shape can be measured by a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).
As a method for measuring the toner shape (circularity), an optical detection zone method is used in which a suspension containing particles is passed through an imaging zone detection zone on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. Is appropriate. In this method, the projected area of the particle can be obtained. The circularity is a value obtained by dividing the circumference of an equivalent circle having the same area as the projected area by the circumference 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 alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration of the dispersion is set to 3000 to 10,000 / μl, and the shape of the toner and the shape distribution of the toner are measured by the above-described apparatus.
[0086]
(Carrier for two components)
When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is 1 to 10 weights of toner with respect to 100 parts by weight of the carrier. Part is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.
[0087]
The carrier may cover 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. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, 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]
Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.
[0089]
The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.
[0090]
【Example】
EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In addition, a part shows a weight part.
[0091]
Example 1
(Synthesis of organic fine particle emulsion)
Production Example 1
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of a sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were charged and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The volume average particle diameter of [Fine Particle Dispersion 1] measured with LA-920 was 0.10 μm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The resin content Tg was 57 ° C.
[0092]
(Preparation of aqueous phase)
Production Example 2
990 parts of water, 80 parts of [fine particle dispersion 1], 40 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7): Sanyo Kasei Kogyo Co., Ltd. and 90 parts of ethyl acetate were mixed and stirred. A liquid was obtained. This is designated as [Aqueous Phase 1].
[0093]
(Synthesis of low molecular weight polyester)
Production Example 3
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 220 parts of bisphenol A ethylene oxide 2-mole adduct, 561 parts of bisphenol A propylene oxide 3-mole adduct, 218 parts of terephthalic acid, 48 parts of adipic acid and dibutyltin Add 2 parts of oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10-15 mmHg, then add 45 parts of trimellitic anhydride into the reaction vessel, and leave for 2 hours at 180 ° C. under normal pressure. The reaction yielded [low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a Tg of 43 ° C., and an acid value of 25.
[0094]
(Prepolymer synthesis)
Production Example 4
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg 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, 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 are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.
[0095]
(Synthesis of ketimine)
Production Example 5
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged 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 Kasei RS-801 Acid value 10, Mw 20000, Tg 64 ° C.): 60 parts, Water: 30 parts are mixed in a Henschel mixer, A mixture in which water was soaked into the pigment aggregate was obtained. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. and pulverized to a size of 1 mmφ with a pulverizer to obtain [Masterbatch 1].
[0097]
(Create oil phase)
Production Example 7
In a container equipped with a stir bar and a thermometer, 378 parts of [Low molecular weight polyester 1], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate are charged 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 in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. The solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.
[0098]
(Emulsification)
Production Example 8
[Pigment / WAX Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 6.6 parts in a container, and TK homomixer (made by Tokushu Kika) at 5,000 rpm for 1 minute After mixing, 1200 parts of [Aqueous phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 20 minutes to obtain [Emulsion slurry 1].
[0099]
(Variation)
Production Example 9
1365 parts of ion exchanged water, 35 parts of carboxymethyl cellulose (CMC Daicel-1280: manufactured by Daicel Chemical Industries, Ltd.) in a container and stirred in an aqueous solution, 1000 parts of [Emulsion slurry 1] were mixed. K. Pipeline homomixer model: PL-2V (manufactured by Special Machine Engineering Co., Ltd.) was flowed at a flow rate of 1000 g / min at 2,000 rpm to obtain [Deformed slurry 1]. The viscosity of the modified slurry 1 at this time was 4000 mPa · s.
[0100]
(Solvent removal)
Production Example 10
[Deformed slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C for 8 hours, aging was performed at 45 ° C for 4 hours to obtain [Dispersion slurry 1].
[0101]
(Washing ⇒ drying)
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
{Circle around (1)} 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): Add 100 parts of 10% aqueous sodium hydroxide to the filter cake of (1), apply ultrasonic vibration, mix with TK homomixer (30 minutes at 12,000 rpm), and then filter under reduced pressure. . This ultrasonic alkali cleaning was performed again (two ultrasonic alkali cleanings).
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(4): Add 300 parts of deionized water to the filter cake of (3), mix with a TK homomixer (10 minutes at 12,000 rpm), and filter twice to obtain [Filter cake 1]. It was.
[Filtration cake 1] was dried at 45 ° C. for 48 hours in a circulating drier and sieved with a mesh having a mesh size of 75 μm to obtain [Toner Base 1].
[0102]
Comparative Example 1
T. of Example 1 K. [Toner base 5] was obtained in the same manner as in Example 1 except that the pipeline homomixer model: PL-2V (manufactured by Tokushu Kika Co., Ltd.) was not used and the flow rate was 1000 g / min at 2,000 rpm.
[0103]
Examples 2-4, Comparative Examples 2-4
The viscosity P and the organic solvent concentration of Example 1 (Production Example 9) were changed as shown in Table 1 except that the thickener and ion-exchanged water concentration were changed, and the viscosity of the deformed slurry was adjusted as shown in Table 1. [Toner bases 2 to 4 and 6 to 8] were obtained in the same manner as in Example 1.
[0104]
(Measurement of shape)
The non-spherical shape is determined by using an optical microscope with a spherical shape as rank 1 as shown in the photograph of FIG. 6, a substantially spherical shape as rank 2 as shown in the photograph of FIG. 5, and a photograph as shown in FIG. Spindle-shaped (rugby ball) and spheres that are about half spherical in rank 3, rank 4 as spindle-shaped but irregular as shown in the photo in FIG. 3, rank spindle-shaped and uniform as shown in the photo in FIG. It was set to 5, and the shape was ranked and judged. In the present invention, the non-spherical shape means a rank of 3 or higher.
Further, in order to maintain the cleaning property for a long period, it is effective to have 25% by number or less of particles having a shape rank of 4 or more and a number-based circle equivalent diameter measured by a flow particle image analyzer of less than 2.0 μm. Measurement of particles having an equivalent circle diameter of less than 2.0 μm can be performed using a flow type particle image analyzer FPIA-1000 manufactured by Sysmex Corporation. An outline of the apparatus and measurement is described in JP-A-8-136439. The measurement was adjusted to a 1% NaCl aqueous solution using primary sodium chloride and then passed through a 0.45 μm filter to 50 to 100 ml of a surfactant, preferably 0.1 to 5 ml of an alkylbenzene sulfonate as a dispersant. In addition, add 1-10 mg of sample. This was subjected to a dispersion treatment for 1 minute with an ultrasonic disperser and measured using a dispersion liquid in which the particle concentration was adjusted to 5000 to 15000 particles / μl. For the measurement of the number of particles, a two-dimensional image area captured by a CCD camera and a diameter of a circle having the same area are calculated as an equivalent circle diameter. From the accuracy of the CCD pixel, a circle equivalent diameter of 0.6 μm or more was effective, and particle measurement data was obtained.
Table 1 shows the rank of the shape of each toner base.
[0105]
[Table 1]

[0106]
In 100 parts of each of the toner bases 1 to 8 obtained as described above, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide were mixed with a Henschel mixer.
[0107]
A developer consisting of 5% by weight of each externally treated toner 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 continuous Ricoh's imgio Neo 450, it was continuously printed and evaluated by the following methods and criteria.
[0108]
[Evaluation method and evaluation criteria]
(Cleanability)
The transfer residual toner on the photosensitive member that has passed the cleaning process is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), measured with a Macbeth reflection densitometer RD514, and the difference from the blank is 0.01 or less. A product was evaluated as ○ (good), and a product exceeding it was evaluated as × (defect).
[0109]
(Film resistance)
The presence or absence of toner filming on the developing roller or the photoreceptor was observed.
Evaluation was made on the assumption that no filming occurred, Δ a filming on streaks was observed, and x an entire filming.
[0110]
[Table 2]

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

Claims (6)

  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. An emulsified dispersion obtained by reacting a solution or dispersion formed by dissolving or dispersing a toner component containing an active hydrogen group in an aqueous medium containing resin fine particles, and at least a thickener. The shape of the toner is made non-spherical by mixing the aqueous solution and passing the mixed solution in which the organic solvent concentration of the obtained mixed solution is adjusted to 3 to 15% by weight through a device that applies shear force to the mixed solution. Then, the toner for developing an electrostatic charge image is obtained by removing the solvent and washing and desorbing the resin fine particles adhering to the surface.   The electrostatic charge image developing toner according to claim 1, wherein the mixed solution has a viscosity P of 2500 to 25000 mPa · s.   The electrostatic image developing toner according to claim 1, wherein the toner has a spindle shape. A developer comprising the electrostatic image developing toner according to claim 1. A developing method having a toner recycling mechanism, wherein the toner for developing an electrostatic charge image according to claim 1 is used. A developing device having a toner recycling mechanism and loaded with the electrostatic image developing toner according to claim 1 as the toner.

Images