JP3639714B2 - Toner for developing electrostatic image, image forming method and process cartridge - Google Patents

Description

＊）粒径範囲の上限は、その数値を含まず、「未満」を表わす。
【００５１】
さらに本発明では、以下の式で定義されるトナーのタップ時の空隙率が０．４５〜０．７０の範囲であることが好ましく、さらに好ましくは０．５０〜０．７０の範囲であるときに優れた帯電性を示す。
空隙率＝（真密度−タップ密度）／真密度
【００５２】
トナーは、主にトナー担持体とトナー規制ブレードとの間でパッキングされた状態で摩擦帯電をする。そのためトナーのパッキング状態の程度はそのトナーの帯電に大きく影響する。トナーが上記範囲の空隙率を有するとき、トナー粒子各個の帯電機会が均一になるため各トナー粒子の帯電量のバラツキが制御され、画像濃度とカブリを高いレベルで調節することが可能となる。
【００５３】
本発明において、トナーのタップ密度の測定はホソカワミクロン（株）製のパウダーテスターを用い、該パウダーテスターに付属している容器を使用して、該パウダーテスターの取扱説明書の手順に従って測定した値を言う。
【００５４】
本発明において、トナーの真密度は以下のようにして測定する。トナー１ｇをＩＲ測定用錠剤成型器に入れ、約１．９６ＭＰａ（２００ｋｇｆ／ｃｍ²）の圧力で１分間加圧し成型する。このサンプルの体積および重量を測定し真密度を求める。
【００５５】
本発明に使用される結着樹脂の種類としては、ポリスチレン、ポリ−Ｐ−クロロスチレン及びポリビニルトルエンの如きスチレン及びその置換体の単重合体；スチレン−Ｐ−クロロスチレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体、スチレン−α−クロルメタクリル酸メチル共重合体、スチレン−アクリロニトリル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体及びスチレン−アクリロニトリル−インデン共重合体の如きスチレン系共重合体；ポリ塩化ビニル；フェノール樹脂；天然変性フェノール樹脂；天然樹脂変性マレイン酸樹脂；ポリアクリル酸及びポリアクリル酸エステルの如きアクリル系樹脂；ポリメタクリル酸及びポリメタクリル酸エステルの如きメタクリル系樹脂；ポリ酢酸ビニール；シリコーン樹脂；ポリエステル樹脂；ポリウレタン；ポリアミド樹脂；フラン樹脂；エポキシ樹脂；キシレン樹脂；ポリビニルブチラール；テルペン樹脂；クマロンインデン樹脂；石油系樹脂が使用できる。さらに、架橋されたスチレン系樹脂も好ましい結着樹脂である。
【００５６】
スチレン系共重合体のスチレンモノマーに対するコモノマーとしては、ビニル系単量体が単独又は組合わせて用いることができる。ビニル系単量体としては、例えば、アクリル酸、アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸ドデシル、アクリル酸オクチル、アクリル酸−２−エチルヘキシル、アクリル酸フェニル、メタクリル酸、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸オクチル及びアクリルアミドの如き二重結合を有するモノカルボン酸もしくはその置換体；例えば、マレイン酸、マレイン酸ブチル、マレイン酸メチル及びマレイン酸ジメチルの如き二重結合を有するジカルボン酸及びその置換体；例えば、塩化ビニル、酢酸ビニル及び安息香酸ビニルの如きビニルエステル類；例えば、エチレン、プロピレン及びブチレンの如きエチレン系オレフィン類；例えば、ビニルメチルケトン及びビニルヘキシルケトンの如きビニルケトン類；例えば、ビニルメチルエーテル、ビニルエチルエーテル及びビニルイソブチルエーテルの如きビニルエーテル類が挙げられる。
【００５７】
ここで架橋剤としては、主として２個以上の重合可能な二重結合を有する化合物が単独又は組合わせて用いられる。このような化合物としては、例えば、ジビニルベンゼン及びジビニルナフタレンの如き芳香族ジビニル化合物；例えば、エチレングリコールジアクリレート、エチレングリコールジメタクリレート及び１，３−ブタンジオールジメタクリレートの如き二重結合を２個有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド及びジビニルスルホンの如きジビニル化合物；及び３個以上のビニル基を有する化合物；が挙げられる。
【００５８】
本発明に係る樹脂組成物の高分子量成分の重合法としては、乳化重合法や懸濁重合法が挙げられる。
【００５９】
このうち、乳化重合法は、水にほとんど不溶の単量体（モノマー）を乳化剤で小さい粒子として水相中に分散させ、水溶性の重合開始剤を用いて重合を行う方法である。この方法では反応熱の調節が容易であり、重合の行われる相（重合体と単量体からなる油相）と水相とが別であるから停止反応速度が小さく、その結果重合速度が大きく、高重合度のものが得られる。更に、重合プロセスが比較的簡単であること、及び重合生成物が微細粒子であるために、トナーの製造において、着色剤及び荷電制御剤その他の添加物との混合が容易であること等の理由から、トナー用バインダー樹脂の製造方法として有利な点がある。
【００６０】
しかし、添加した乳化剤のため生成重合体が不純になり易く、重合体を取り出すには塩析などの操作が必要で、この不便を避けるためには懸濁重合が好都合である。
【００６１】
懸濁重合においては、水系溶媒１００重量部に対して、モノマー１００重量部以下（好ましくは１０〜９０重量部）で行うのが良い。使用可能な分散剤としては、ポリビニルアルコール、ポリビニルアルコール部分ケン化物及びリン酸カルシウムが挙げられる。分散剤の使用量は、水系溶媒に対するモノマー量で適当量があるが、一般に水系溶媒１００重量部に対して０．０５〜１重量部が用いられる。重合温度は５０〜９５℃が適当であるが、使用する開始剤、目的とするポリマーによって適宜選択すべきである。
【００６２】
本発明にかかる結着樹脂の低分子量成分の合成法としては、公知の方法を用いることができる。しかし、塊状重合法では、高温で重合させて停止反応速度をはやめることで低分子量の重合体を得ることもできるが反応をコントロールしにくい問題点がある。その点、溶融重合法では溶媒によるラジカルの連鎖移動の差を利用することにより、または、開始剤量や反応温度を調節することにより、低分子量重合体を温和な条件で容易に得ることができ、低分子量体を合成する場合には好ましい。なかでも、酸成分や分子量を高度に調節するために、例えば、分子量と組成の異なる重合体を混合して低分子量重合体を得る方法や、組成の異なるモノマー類を後添加する方法を用いることができる。
【００６３】
溶液重合で用いる溶媒としては、キシレン、トルエン、クメン、酢酸セロソルブ、イソプロピルアルコール、ベンゼン等が用いられる。スチレンモノマー混合物の場合はキシレン、トルエン又はクメンが好ましい。重合生成するポリマーによって適宜選択される。
【００６４】
本発明では必要に応じてトナー中にワックスを含有していることが好ましい。用いられるワックスとしては、例えば、パラフィンワックス及びその誘導体、マイクロクリスタリンワックス及びその誘導体、フィッシャートロプシュワックス及びその誘導体、ポリオレフィンワックス及びその誘導体、カルナバワックス及びその誘導体が挙げられる。誘導体は、酸化物、ビニル系モノマーとのブロック共重合物、及びビニル系モノマーとのグラフト変性物を含む。
【００６５】
本発明で好ましく用いられるワックスは、下記一般式で表わされるものである。
【００６６】
Ｒ−Ｙ
【００６７】
式中、Ｒは炭化水素基を示し、
Ｙは水素、水酸基、カルボキシル基、アルキルエーテル基、エステル基又はスルホニル基を示す。
【００６８】
上記のＲ−Ｙで示される化合物は、ＧＰＣによる重量平均分子量（Ｍｗ）が３０００以下、好ましくは５００〜２５００であることが良い。
【００６９】
具体的な化合物例としては、下記式（Ａ），（Ｂ）及び（Ｃ）で示される化合物が挙げられる。
（Ａ）ＣＨ₃（ＣＨ₂）_nＣＨ₂ＯＨ（ｎ＝２０〜３００）
（Ｂ）ＣＨ₃（ＣＨ₂）_nＣＨ₂ＣＯＯＨ（ｎ＝２０〜３００）
（Ｃ）ＣＨ₃（ＣＨ₂）_nＣＨ₂ＯＣＨ₂（ＣＨ₂）_mＣＨ₃
（ｎ＝２０〜２００，ｍ＝０〜１００）
これらの化合物は、（Ａ）化合物の誘導体であり、主鎖は直鎖状の飽和炭化水素である。化合物（Ａ）から誘導される化合物であれば上記例に示した以外のものでも使用できる。上記ワックスを用いることにより、本発明のトナーは低温での定着性及び高温での耐オフセット性を高度に満足することが可能となる。
【００７０】
上記化合物のなかでも特に上記（Ａ）式で表わされる高分子アルコールを主成分として用いたワックスが好ましい。上記ワックスはすべり性がよく、特に耐オフセットに優れている。
【００７１】
本発明において、ワックスの分子量分布は、ＧＰＣ（ゲルパーミエーションクロマトグラフィー）によって次の条件で測定される。
【００７２】
＜ワックスのＧＰＣ測定条件＞
装置 ：ＧＰＣ−１５０Ｃ（ウォーターズ社製）
カラム：ＧＭＨ−ＨＴ（東ソー社製）の２連
温度 ：１３５℃
溶媒 ：ｏ−ジクロロベンゼン（０．１％アイオノール添加）
流速 ：１．０ｍｌ／ｍｉｎ．
試料 ：濃度０．１５重量％の試料を０．４ｍｌ注入
【００７３】
以上の条件で測定し、試料の分子量算出にあたっては単分散ポリスチレン標準試料により作成した分子量校正曲線を使用する。更に、Ｍａｒｋ−Ｈｏｕｗｉｎｋ粘度式から導き出される換算式で換算することによって算出される。
【００７４】
これらのワックスは結着樹脂１００重量部に対し、０．５重量部乃至２０重量部用いられることが好ましい。
【００７５】
トナーは、着色剤として、磁性体を含有する磁性トナーとして用いることが好ましい。磁性トナーの磁性体含有量は、結着樹脂１００重量部に対して、３０〜２００重量部、好ましくは、５０〜１５０重量部であることが良い。
【００７６】
本発明においては、トナーに負荷電制御剤を添加して負荷電性磁性トナーとすることが、より好ましい。
【００７７】
負荷電制御剤の具体例としては、特公昭４１−２０１５３号公報、同４２−２７５９６号公報、同４４−６３９７号公報及び同４５−２６４７８号公報に記載されているモノアゾ染料の金属錯体；特開昭５０−１３３３３８号公報に記載されているニトロアミン酸及びその塩；Ｃ．Ｉ．１４６４５の如き染顔料；特公昭５５−４２７５２号公報、特公昭５８−４１５０８号公報、特公昭５８−７３８４号公報及び特公昭５９−７３８５号公報に記載されているサリチル酸、ナフトエ酸、ダイカルボン酸のＺｎ，Ａｌ，Ｃｏ，Ｃｒ，Ｆｅの如き金属錯体；スルホン化した銅フタロシアニン顔料；ニトロ基、ハロゲンを導入したスチレンオリゴマー；塩素化パラフィンを挙げることができる。特に分散性に優れ、画像濃度の安定性やカブリの低減に効果のある、一般式（Ｉ）で表わされるアゾ系金属錯体及び一般式（ＩＩ）で表わされる塩基性有機酸金属錯体が好ましい。
【００７８】
【化１】

【００７９】
【化２】

【００８０】
そのうち上記式（Ｉ）で表わされるアゾ系金属錯体がより好ましく、とりわけ、中心金属がＦｅである下記式（ＩＩＩ）で表されるアゾ系鉄錯体が最も好ましい。
【００８１】
【化３】

【００８２】
次に、上記式（ＩＩＩ）で示されるアゾ系鉄錯体の具体例を下記に示す。
【００８３】
【化４】

【００８４】
【化５】

【００８５】
本発明において、荷電制御剤の含有量は結着樹脂１００重量部に対し０．１〜５重量部が好ましく、特に０．２〜３重量部が好ましい。荷電制御剤の含有量が過大の場合にはトナーの流動性が悪化し、カブリが生じやすく、過小のときには十分な帯電量が得られにくい。
【００８６】
本発明のトナーは、環境安定性，帯電安定性，現像性，流動性，保存性向上のため、親水性無機微粉体または疎水性無機微粉体の如き無機微粉体Ｂが外添剤粒子として、前述した微粒子Ａと共にトナー粒子と混合されることが好ましい。この無機微粉体Ｂとしては、例えば、シリカ微粉末、酸化チタン微粉末又はそれらの疎水化物が挙げられる。それらは、単独あるいは併用して用いることが好ましい。
【００８７】
シリカ微粉体はケイ素ハロゲン化合物の蒸気相酸化により生成されたいわゆる乾式法またはヒュームドシリカと称される乾式シリカ、及び水ガラス等から製造されるいわゆる湿式シリカの両方が使用可能であるが、表面及び内部にあるシラノール基が少なく、またＮａ₂Ｏ，ＳＯ₃ ^2-等の製造残渣のない乾式シリカの方が好ましい。乾式シリカにおいては、製造工程において例えば、塩化アルミニウム，塩化チタンの如き他の金属ハロゲン化合物を硅素ハロゲン化合物と共に用いることによって、シリカと他の金属酸化物の複合微粉体を得ることも可能でありそれらも包含する。
【００８８】
さらにシリカ微粉体は疎水化処理されているものが好ましい。疎水化処理するには、有機ケイ素化合物の如きシリカ微粉体と反応あるいは物理吸着する処理剤で化学的に処理することによって付与される。好ましい方法としては、ケイ素ハロゲン化合物の蒸気相酸化により生成された乾式シリカ微粉体をシランカップリング剤で処理した後、あるいはシランカップリング剤で処理すると同時にシリコーンオイルの如き有機ケイ素化合物で処理する方法が挙げられる。
【００８９】
疎水化処理に使用されるシランカップリング剤としては、例えばヘキサメチルジシラザン、トリメチルシラン、トリメチルクロルシラン、トリメチルエトキシシラン、ジメチルジクロルシラン、メチルトリクロルシラン、アリルジメチルクロルシラン、アリルフェニルジクロルシラン、ベンジルジメチルクロルシラン、ブロムメチルジメチルクロルシラン、α−クロルエチルトリクロルシラン、β−クロルエチルトリクロルシラン、クロルメチルジメチルクロルシラン、トリオルガノシランメルカプタン、トリメチルシリルメルカプタン、トリオルガノシリルアクリレート、ビニルジメチルアセトキシシラン、ジメチルエトキシシラン、ジメチルジメトキシシラン、ジフェニルジエトキシシラン、ヘキサメチルジシロキサン、１，３−ジビニルテトラメチルジシロキサン、１，３−ジフェニルテトラメチルジシロキサン及び１分子当たり２から１２個のシロキサン単位を有し末端に位置する単位にそれぞれ１個宛のケイ素原子に結合した水酸基を含有したジメチルポリシロキサンが挙げられる。
【００９０】
有機ケイ素化合物としては、シリコーンオイルが挙げられる。好ましいシリコーンオイルとしては、２５℃における粘度がおよそ３０〜１，０００センチストークスのものが用いられる。シリコーンオイルとしては、例えばジメチルシリコーンオイル、メチルフェニルシリコーンオイル、α−メチルスチレン変性シリコーンオイル、クロルフェニルシリコーンオイル、フッ素変性シリコーンオイルが挙げられる。
【００９１】
シリコーンオイル処理の方法は、例えばシランカップリング剤で処理されたシリカ微粉体とシリコーンオイルとをヘンシェルミキサーの如き混合機を用いて直接混合しても良いし、ベースとなるシリカへシリコーンオイルを噴射する方法によっても良い。あるいは適当な溶剤にシリコーンオイルを溶解あるいは分散せしめた後、ベースのシリカ微粉体とを混合し、溶剤を除去する方法でも良い。
【００９２】
この無機微粉体の平均粒径は一次粒径として、０．００２〜０．２μｍであることが、帯電安定性や流動性向上の点で好ましい。
【００９３】
さらに本発明では転写中抜けや、感光ドラムへのトナー融着防止のために、シリコーンオイルまたはシリコーンワニスの存在量が２０〜９０重量％の微粒子凝集体Ｃが外添剤微粒子として混合されていることが、より好ましい。
【００９４】
本発明において、微粒子とシリコーンオイルまたはシリコーンワニスとからなる微粒子凝集体Ｃに用いる該微粒子としては、無機化合物の微粒子または有機化合物の微粒子が使用される。有機化合物としては、スチレン樹脂、アクリル樹脂、シリコーン樹脂、シリコーンゴム、ポリエステル樹脂、ウレタン樹脂、ポリアミド樹脂、ポリエチレン樹脂、フッ素樹脂の如き樹脂粒子脂肪族系化合物が挙げられる。
【００９５】
無機化合物としては、ＳｉＯ₂，ＧｅＯ₂，ＴｉＯ₂，ＳｎＯ₂，Ａｌ₂Ｏ₃，Ｂ₂Ｏ₃，Ｐ₂Ｏ₅，Ａｓ₂Ｏ₃の如き金属酸化物；ケイ酸塩，ホウ酸塩，リン酸塩，ゲルマン酸塩，ホウケイ酸塩，アルミノケイ酸塩，アルミノホウ酸塩，アルミノホウケイ酸塩，タングステン酸塩，モリブデン酸塩，テルル酸塩の如き金属酸化物塩；及びこれらの複合化合物；炭化ケイ素，窒化ケイ素，アモルファスカーボン；が挙げられる。これらは、単独あるいは混合して用いられる。
【００９６】
これらの中で金属酸化物が好ましく用いられ、Ｓｉ，Ａｌ及びＴｉからなるグループから選択される金属の酸化物又は複合化合物がより好ましい。表面をカップリング剤によりあらかじめ疎水化したものを用いてもよい。
【００９７】
本発明に用いるシリコーンオイルとしては下記一般式（ＩＶ）
【００９８】
【化６】

【００９９】
Ｒ ：炭素数１〜３のアルキル基
Ｒ’：アルキル、ハロゲン変性アルキル、フェニル及び変性フェニルからな
るグループから選択されるシリコーンオイル変性基
Ｒ”：炭素数１〜３のアルキル基又はアルコキシ基
で表わされるものが好ましい。例えばジメチルシリコーンオイル、アルキル変性シリコーンオイル、α−メチルスチレン変性シリコーンオイル、クロルフェニルシリコーンオイル、フッ素変性シリコーンオイルが挙げられる。
【０１００】
本発明において、シリコーンオイルとしては、式（Ｖ）で表わされる構造をもつアミノ変性シリコーンオイルも使用できる。
【０１０１】
【化７】

【０１０２】
（ここで、Ｒ₃及びＲ₈は水素，アルキル基，アリール基又はアルコキシ基を表わし、Ｒ₄はアルキレン基又はフェニレン基を表わし、Ｒ₅は含窒素複素環をその構造に有する化合物を表わし、Ｒ₆及びＲ₇は水素，アルキル基又はアリール基を表わし、Ｒ₄はなくてもよい。ただし上記のアルキル基，アリール基，アルキレン基及びフェニレン基はアミンを含有していても良いし、帯電性を損ねない範囲でハロゲンを置換基として有していても良い。ｐは１以上の数であり、ｑ及びｒは０を含む正の数である。ただしｑ＋ｒは１以上の正の数である。）
【０１０３】
上記構造中最も好ましい構造は、窒素原子を含む側鎖中の窒素原子の数が１か２であるものである。
【０１０４】
窒素を含有する不飽和複素環として下記にその一例を挙げる。
【０１０５】
【化８】

【０１０６】
窒素を含有する飽和複素環の一例を以下に挙げる。
【０１０７】
【化９】

【０１０８】
ただし、本発明は何ら上記化合物例に拘束されるものではないが、好ましくは５員環又は６員環の複素環をもつものが良い。
【０１０９】
誘導体としては、上記化合物群に炭化水素基、ハロゲン基、アミノ基、ビニル基、メルカプト基、メタクリル基、グリシドキシ基、ウレイド基を導入した誘導体が例示される。
【０１１０】
これらは１種または２種以上の混合系で用いてもよい。
【０１１１】
本発明に用いられるシリコーンワニスとしては、例えばメチルシリコーンワニス及びフェニルメチルシリコーンワニスを挙げることができ、特に、メチルシリコーンワニスが好ましい。
【０１１２】
メチルシリコーンワニスは、下記構造式で示されるＴ³¹単位、Ｄ³¹単位、Ｍ³¹単位よりなるポリマーであり、かつＴ³¹単位を多量に含む三次元ポリマーである。
【０１１３】
【化１０】

【０１１４】
メチルシリコーンワニスまたはフェニルメチルシリコーンワニスは、具体的には例えば下記構造式（ＶＩ）で示されるような化学構造を有する物質である。
【０１１５】
【化１１】

（Ｒ³¹は、メチル基またはフェニル基を表わす。）
【０１１６】
上記シリコーンワニスにおいて、特にＴ³¹単位は、良好な熱硬化性を付与し、三次元網状構造とするために有効な単位である。上記Ｔ³¹単位は、シリコーンワニス中に１０〜９０モル％、特に３０〜８０モル％の割合で含まれることが好ましい。
【０１１７】
このようなシリコーンワニスは、分子鎖の末端もしくは側鎖に水酸基を有しており、この水酸基の脱水縮合によって硬化することとなる。この硬化反応を促進させるために用いることができる硬化促進剤としては、例えば、亜鉛、鉛、コバルト、スズの如き脂肪酸塩；トリエタノールアミン、ブチルアミンの如きアミン類；を挙げることができる。このうち特にアミン類を好ましく用いることができる。
【０１１８】
上記の如きシリコーンワニスをアミノ変性シリコーンワニスとするためには、前記Ｔ³¹単位、Ｄ³¹単位、Ｍ³¹単位中に存在する一部のメチル基あるいはフェニル基をアミノ基を有する基に置換すればよい。アミノ基を有する基としては、例えば下記構造式（ＶＩＩ）〜（ＸＩ）で示されるものを挙げることができる。が、これらに限定されるものではない。
【０１１９】
【化１２】

【０１２０】
上記シリコーンオイルまたはシリコーンワニスは２５℃における粘度が、好ましくは５０乃至２００，０００センチストークス、さらに好ましくは５００〜１５０，０００センチストークス、より好ましくは１，５００〜１００，０００センチストークス、さらに好ましくは３，０００〜８０，０００センチストークスが良い。
【０１２１】
５０センチストークス未満では、多量のシリコーンオイルまたはシリコーンワニスの良好な粒子化が困難であるとともに、微粒子凝集体に安定性が無く、熱および機械的な応力により、画質が劣化する傾向がある。
【０１２２】
２００，０００センチストークスを超える場合は、シリコーンオイルまたはシリコーンワニスの粒子化が困難になる傾向がある。
【０１２３】
シリコーンオイルまたはシリコーンワニスの粘度測定は、ビスコテスターＶＴ５００（ハーケ社製）を用いて行なう。
【０１２４】
いくつかあるＶＴ５００用粘度センサーの一つを選び（任意）、そのセンサー用の測定セルに測定試料を入れて測定する。装置上に表示された粘度（Ｐａｓ）はｃＳｔ（センチストークス）に換算する。
【０１２５】
微粒子凝集体Ｃにおけるシリコーンオイルまたはシリコーンワニスの処理量は、２０〜９０重量％、好ましくは２７〜８５重量％、さらに好ましくは４０〜８０重量％の場合に初期の効果が得られる。
【０１２６】
シリコーンオイルまたはシリコーンワニスの処理量が２０重量％未満の場合、転写中抜けや感光ドラムへのトナー融着の改良に効果が少なく、９０重量％を超える場合は、シリコーンオイルまたはシリコーンワニスを粒子に保持しにくくなり、過剰のシリコーンオイルまたはシリコーンワニスがトナー粒子を凝集させ、画質の劣化を起し易くなる。
【０１２７】
シリコーンオイルまたはシリコーンワニスと微粒子から構成される微粒子凝集体Ｃの適用量はトナー１００重量部に対して、好ましくは０．０１〜１０重量部、より好ましくは０．０３〜５重量部、さらに好ましくは０．０５〜２重量部が良い。０．０１重量部未満では、転写中抜けや感光ドラムへのトナー融着の改良の効果が少なく、また、１０重量部を超える場合は、トナーの定着性を損なう傾向がある。
【０１２８】
本発明に係るシリコーンオイルまたはシリコーンワニスと微粒子から構成される微粒子凝集体Ｃは、シリコーンオイルまたはシリコーンワニスという離型性の良好な物質を２０重量％〜９０重量％と比較的に多量に含んでおり、それがトナーと感光体表面との離型性の向上に働く。
【０１２９】
シリコーンワニスよりシリコーンオイルの方が感光体表面に塗布され易いので、シリコーンオイルの方が好ましい。またシリコーンオイルにはアルコキシ基は含まれないことが好ましい。
【０１３０】
この微粒子凝集体Ｃの平均粒径は、０．５〜５０μｍであることが、トナー中での均一混合性の点で好ましい。
【０１３１】
本発明においては、現像性や流動性の改善のため、トナーに外添剤粒子として樹脂微粒子Ｄを添加することが、より好ましい。
【０１３２】
該樹脂微粒子Ｄは、乳化重合法またはスプレードライ法によって生成条件を調整することにより製造され得る。好ましくは、スチレン、アクリル酸、メチルメタクリレート、ブチルアクリレート、２−エチルヘキシルアクリレートの如き、トナー用結着樹脂に用いられる成分を乳化重合法により単独あるいは共重合して得られるガラス転移点８０℃以上の樹脂粒子が良好な効果を示す。
【０１３３】
ジビニルベンゼンの如き架橋剤で架橋されていてもよく、表面が金属、金属酸化物、顔料、染料、界面活性剤で処理されても良い。
【０１３４】
本発明における樹脂微粒子Ｄは、スチレン系モノマー単位を５１重量％以上含む、ブロックまたはランダムスチレン系共重合体であることが特に好ましい。スチレン系樹脂微粒子は、通常、トナーの結着樹脂に用いられるスチレン−アクリル樹脂やポリエステル樹脂と帯電列が近く、トナー粒子との相互帯電が少なく流動性が悪化しにくい。
【０１３５】
樹脂微粒子Ｄ中に含まれるスチレンモノマー単位が５１重量％未満であるとトナーの凝集性が強くなり、流動性が悪化し、画像白抜け、画像濃度ムラが生じやすい。
【０１３６】
この樹脂微粒子Ｄの平均粒径は、０．０１〜１．０μｍであることが、現像性改善の点で好ましい。
【０１３７】
上記の無機微粉体Ｂ、微粒子凝集体Ｃ及び樹脂微粒子Ｄの平均粒径は、以下の方法で測定した値である。
【０１３８】
電子顕微鏡Ｓ−８００（日立製作所社製）を用いて、無機微粉体Ｂは１０万乃至２０万倍、微粒子凝集体Ｃは１００乃至２０００倍、樹脂微粒子Ｄは１００００乃至２００００倍の倍率で写真撮影を行い、撮影された微粒子から、無機微粉体Ｂは粒径５ｎｍ以上の粒子について、微粒子凝集体Ｃは粒径０．２μｍ以上の粒子について、樹脂微粒子Ｄは０．００５μｍ以上の粒子について、ランダムに１００乃至２００個を抽出し、ノギス等の測定機器を用いてそれぞれの直径を測定し、平均化したものを各微粒子の平均粒径とした。
【０１３９】
本発明の画像形成方法の好ましい一具体例を図３を参照しながら説明する。
【０１４０】
一次帯電器としての帯電ローラーからなる接触帯電部材１１で静電潜像担持体としてのＯＰＣ感光ドラム３表面を負極性に帯電し、レーザ光による露光５によりイメージスキャニングによりデジタルの静電潜像を形成し、カウンター方向に設置されたウレタンゴム製の弾性ブレード８および磁石１５を内包している現像スリーブ６を具備する現像手段としての現像装置１の負摩擦帯電性磁性トナー１３で該潜像を反転現像する。または、アモルファスシリコン感光体を使用し、感光体を正極性に帯電し、静電潜像を形成し、負摩擦帯電性磁性トナーを用いて正規現像をおこなう。現像スリーブ６に、バイアス印加手段１２により交互バイアス、パルスバイアス及び／又は直流バイアスが印加されている。転写紙Ｐが搬送されて、転写部にくると転写手段としての転写ローラーからなる接触転写部材４により転写紙Ｐの背面（感光ドラム側と反対面）から帯電をすることにより、感光ドラム表面上のトナー画像が転写紙Ｐ上へ静電転写される。感光ドラム３から分離された転写紙Ｐは、内部に加熱手段２０を有する加熱ローラー２１と加圧ローラー２２を有する加熱加圧定着器により転写紙Ｐ上のトナー画像を定着するために定着処理される。
【０１４１】
転写工程後の感光ドラム３に残留する磁性トナーは、クリーニングブレード７を有するクリーニング器１４で除去される。クリーニング後の感光ドラム３は、イレース露光１０により除電され、再度、一次帯電器１１による帯電工程から始まる工程が繰り返される。
【０１４２】
静電潜像担持体（感光ドラム）は感光層及び導電性基体を有し、矢印方向に動く。現像剤担持体である非磁性円筒の現像スリーブ６は、現像部において静電潜像担持体表面と同方向に進むように回転する。非磁性円筒の現像スリーブ６の内部には、磁界発生手段である多極永久磁石１５（マグネットロール）が回転しないように配されている。現像装置１内の磁性トナー１３は非磁性円筒面上に塗布され、かつ現像スリーブ６の表面と磁性トナー粒子との摩擦によって、磁性トナー粒子はマイナスのトリボ電荷が与えられる。さらに弾性ドクターブレード８を配置することにより、トナー層の厚さを薄く（３０μｍ〜３００μｍ）且つ均一に規制して、現像部における感光ドラム３と現像スリーブ６の間隙よりも薄いトナー層を非接触となるように形成する。このスリーブ６の回転速度を調整することにより、スリーブ表面速度が静電潜像担持体表面の速度と実質的に等速、もしくはそれに近い速度となるようにする。
【０１４３】
現像スリーブ６に交流バイアスまたはパルスバイアスをバイアス手段１２により印加しても良い。この交流バイアスはｆが２００〜４，０００Ｈｚ、Ｖｐｐが５００〜３，０００Ｖであることが好ましい。
【０１４４】
現像部分における磁性トナー粒子の転移に際し、静電潜像を保持する感光ドラム３の表面の静電的力及び交流バイアスまたはパルスバイアスの作用によって磁性トナー粒子は静電潜像側に転移する。
【０１４５】
上述の感光ドラムの如き静電潜像担持体や現像装置、クリーニング手段などの構成要素のうち、複数のものを装置ユニットとして一体に結合してプロセスカートリッジを構成し、このプロセスカートリッジを装置本体に対して着脱可能に構成しても良い。例えば、帯電手段及び現像装置を感光ドラムとともに一体に支持してプロセスカートリッジを形成し、装置本体に着脱自在の単一ユニットとし、装置本体のレールなどの案内手段を用いて着脱自在の構成にしても良い。このとき、上記のプロセスカートリッジのほうにクリーニング手段を伴って構成しても良い。
【０１４６】
図４は本発明のプロセスカートリッジの一実施例を示している。本実施例では、現像装置１、ドラム状の静電潜像担持体（感光ドラム）３、クリーナ１４、一次帯電器１１を一体としたプロセスカートリッジ１８が例示される。
【０１４７】
プロセスカートリッジにおいては、現像装置１の磁性トナー１３がなくなった時に新たなカートリッジと交換される。
【０１４８】
本実施例では、現像装置１は磁性トナー１３を保有しており、現像時には、感光ドラム３と現像スリーブ６との間に所定の電界が形成され、現像工程が好適に実施されるためには、感光ドラム３と現像スリーブ６との間の距離は非常に大切である。本実施例では例えば３００μｍ中心とし、誤差が±２０μｍとなるように調整される。
【０１４９】
図４に示すプロセスカートリッジにおいて、現像装置１は磁性トナー１３を収容するためのトナー容器２と、トナー容器２内の磁性トナー１３をトナー容器２から静電潜像担持体３に対面した現像域へと担持し搬送する現像スリーブ６と、現像スリーブ６にて担持され、現像域へと搬送される磁性トナーを所定厚さに規制し該現像スリーブ上にトナー薄層を形成するための弾性ブレード８とを有する。
【０１５０】
前記現像スリーブ６は、任意の構造とし得る。通常は、磁石１５を内蔵した非磁性の現像スリーブ６から構成される。現像スリーブ６は図示されるように円筒状の回転体とすることもできる。循環移動するベルト状とすることも可能である。その材質としては通常、アルミニウムやＳＵＳが用いられることが好ましい。
【０１５１】
前記弾性ブレード８は、ウレタンゴム、シリコーンゴム、ＮＢＲの如きゴム弾性体；リン青銅、ステンレス板の如き金属弾性体；ポリエチレンテレフタレート、高密度ポリエチレン等の如き樹脂弾性体で形成された弾性板で構成される。弾性ブレード８は、その部材自体のもつ弾性により現像スリーブ６に当接され、鉄の如き剛体から成るブレード支持部材９にてトナー容器２に固定される。弾性ブレード８は、線圧５〜８０ｇ／ｃｍで現像スリーブ６の回転方向に対してカウンター方向に当接することが好ましい。
【０１５２】
弾性ブレード８の代わりに、鉄のごとき磁性ドクターブレードを用いることも可能である。
【０１５３】
一次帯電手段としては、以上のごとく接触帯電手段として帯電ローラー１１を用いて説明したが、帯電ブレード、帯電ブラシの如き接触帯電手段でもよく、更に、非接触のコロナ帯電手段でもよい。しかしながら、帯電によるオゾンの発生が少ない点で接触帯電手段の方が好ましい。転写手段としては、以上のごとく転写ローラー４を用いて説明したが転写ブレードの如き接触帯電手段でもよく、更に非接触のコロナ転写手段でもよい。しかしながら、こちらも転写によるオゾンの発生が少ない点で接触帯電手段の方が好ましい。
【０１５４】
本発明の画像形成方法をファクシミリのプリンターに適用する場合には、光像露光Ｌは受信データをプリントするための露光になる。図５はこの場合の一例をブロック図で示したものである。
【０１５５】
コントローラ３１は画像読取部３０とプリンター３９を制御する。コントローラ３１の全体はＣＰＵ３７により制御されている。画像読取部からの読取データは、送信回路３３を通して相手局に送信される。相手局から受けたデータは受信回路３２を通してプリンター３９に送られる。画像メモリには所定の画像データが記憶される。プリンタコントローラ３８はプリンター３９を制御している。３４は電話である。
【０１５６】
回線３５から受信された画像（回線を介して接続されたリモート端末からの画像情報）は、受信回路３２で復調された後、ＣＰＵ３７は画像情報の複号処理を行い順次画像メモリ３６に格納される。そして、少なくとも１ページの画像がメモリ３６に格納されると、そのページの画像記録を行う。ＣＰＵ３７は、メモリ３６より１ページの画像情報を読み出しプリンタコントローラ３８に複合化された１ページの画像情報を送出する。プリンタコントローラ３８は、ＣＰＵ３７からの１ページの画像情報を受け取るとそのページの画像情報記録を行うべく、プリンタ３９を制御する。
【０１５７】
尚、ＣＰＵ３７は、プリンタ３９による記録中に、次のページの受信を行っている。
【０１５８】
以上の様に、画像の受信と記録が行われる。
【０１５９】
【実施例】
以上本発明の基本的な構成と特色について述べたが、以下実施例に基づいて具体的に本発明について説明する。しかしながら、これによって本発明の実施の態様がなんら限定されるものではない。なお、実施例中の部数は重量部である。
【０１６０】
（微粒子製造例）
炭酸ストロンチウム６００ｇと酸化チタン３２０ｇをボールミルにて、８時間湿式混合した後濾過乾燥した。この混合物を５ｋｇ／ｃｍ²の圧力で成型し、１１００℃の温度で８時間仮焼した。
【０１６１】
得られたチタン酸ストロンチウムをジェット気流を用いた粉砕機により粉砕し、風力分級機を用いて分級しある程度粒径をそろえた後、水中に分散させ、遠心分離機でより精密な分級を行い、乾燥後解砕処理することで、フロー式粒子像分析装置による個数基準の粒度分布において円相当平均径が１．４μｍ、ｂ−ａが−０．５１であるチタン酸ストロンチウム微粒子Ｉを得た。
【０１６２】
同様に粉砕、分級を行い表２に示す微粒子を調製した。
【０１６３】

【０１６４】
上記材料を予備混合した後、１３０℃に設定した二軸混練押出機によって溶融混練を行った。混練物を冷却後粗粉砕し、ジェット気流を用いて粉砕機によって微粉砕し、さらにエルボジェット分級機を用いて２回分級を行い、トナー粒子（重量平均粒径５．９１μｍ、体積平均粒径５．１０μｍ、２．００〜３．１７μｍの粒子が１４．３個数％、１．００μｍ以上２．００μｍ未満の粒子が３．１個数％）を得た。

上記の得られたトナー粒子１００部に対して、上記の材料をヘンシェルミキサーで混合して、表３の実施例１に示したような静電荷像現像用トナーを得た。
【０１６５】
＜実施例２＞
実施例１と同様にしてトナー粒子（重量平均粒径５．６３μｍ、体積平均粒径４．８７μｍ、２．００〜３．１７μｍの粒子が２６．５個数％、１．００μｍ以上２．００μｍ未満の粒子が４．２個数％）を得、チタン酸ストロンチウムの代わりに酸化チタンＩ ２．０部を使用する以外は同様にして、表３の実施例２に示したような静電荷像現像用トナーを得た。
【０１６６】
＜実施例３＞
実施例１と同様にしてトナー粒子（重量平均粒径５．７８μｍ、体積平均粒径４．９９μｍ、２．００〜３．１７μｍの粒子が１４．２個数％、１．００μｍ以上２．００μｍ未満の粒子が４．４個数％）を得、チタン酸ストロンチウムの代わりにステアリン酸亜鉛Ｉ ０．５部を使用する以外は同様にして、表３の実施例３に示したような静電荷像現像用トナーを得た。
【０１６７】
＜実施例４＞
実施例１と同様にしてトナー粒子（重量平均粒径６．４５μｍ、体積平均粒径５．５３μｍ、２．００〜３．１７μｍの粒子が５．５個数％、１．００μｍ以上２．００μｍ未満の粒子が８．９個数％）を得、チタン酸ストロンチウムの代わりにアクリル樹脂粒子Ｉ ０．０９部を使用する以外は同様にして、表３の実施例４に示したような静電荷像現像用トナーを得た。
【０１６８】
＜実施例５＞
実施例１と同様にしてトナー粒子（重量平均粒径５．８２μｍ、体積平均粒径５．０２μｍ、２．００〜３．１７μｍの粒子が３１．４個数％、１．００μｍ以上２．００μｍ未満の粒子が７．５個数％）を得、チタン酸ストロンチウムＩ１．０部を使用する以外は同様にして、表３の実施例５に示したような静電荷像現像用トナーを得た。
【０１６９】
＜実施例６＞
実施例１と同様にしてトナー粒子（重量平均粒径５．１０μｍ、体積平均粒径４．４４μｍ、２．００〜３．１７μｍの粒子が２０．１個数％、１．００μｍ以上２．００μｍ未満の粒子が２．０個数％）を得、チタン酸ストロンチウムＩ１．５部を使用する以外は同様にして、表３の実施例６に示したような静電荷像現像用トナーを得た。
【０１７０】
＜実施例７＞
実施例１と同様にしてトナー粒子（重量平均粒径５．８７μｍ、体積平均粒径５．０６μｍ、２．００〜３．１７μｍの粒子が１４．４個数％、１．００μｍ以上２．００μｍ未満の粒子が０．８個数％）を得、チタン酸ストロンチウムＩ０．１部を使用する以外は同様にして、表３の実施例７に示したような静電荷像現像用トナーを得た。
【０１７１】
＜実施例８＞
実施例１と同様にしてトナー粒子（重量平均粒径６．３８μｍ、体積平均粒径５．４８μｍ、２．００〜３．１７μｍの粒子が１２．８個数％、１．００μｍ以上２．００μｍ未満の粒子が１．１個数％）を得、チタン酸ストロンチウムＩ０．１部を使用する以外は同様にして、表３の実施例８に示したような静電荷像現像用トナーを得た。
【０１７２】
＜実施例９＞
実施例１と同様にしてトナー粒子（重量平均粒径５．７２μｍ、体積平均粒径４．９６μｍ、２．００〜３．１７μｍの粒子が１６．９個数％、１．００μｍ以上２．００μｍ未満の粒子が８．２個数％）を得、チタン酸ストロンチウムＩＩ １．０部を使用する以外は同様にして、表３の実施例９に示したような静電荷像現像用トナーを得た。
【０１７３】
＜実施例１０＞
実施例１と同様にしてトナー粒子（重量平均粒径５．９０μｍ、体積平均粒径５．０８μｍ、２．００〜３．１７μｍの粒子が１５．０個数％、１．００μｍ以上２．００μｍ未満の粒子が２．９個数％）を得、チタン酸ストロンチウムＩＩＩ １．０部を使用する以外は同様にして、表３の実施例１０に示したような静電荷像現像用トナーを得た。
【０１７４】
＜実施例１１＞
エルボジェットによる分級を１回しか行なわなかった以外は実施例１と同様にして、トナー粒子（重量平均粒径５．８６μｍ、体積平均粒径５．０３μｍ、２．００〜３．１７μｍの粒子が２２．７個数％、１．００μｍ以上２．００μｍ未満の粒子が１２．０個数％）を得、チタン酸ストロンチウムＩ ０．８部を使用することも同様にして、表３の実施例１１に示したような静電荷像現像用トナーを得た。
【０１７５】
＜実施例１２＞
実施例１での分級条件を変更してトナー粒子（重量平均粒径６．１５μｍ、体積平均粒径５．２８μｍ、２．００〜３．１７μｍの粒子が１０．７個数％、１．００μｍ以上２．００μｍ未満の粒子が５．１個数％）を得、実施例１と同様に外添を行なって、表３の実施例１２に示したような静電荷像現像用トナーを得た。
【０１７６】
上記の外添後のトナー及び外添剤のトナー粒子のフロー式粒子像分析装置によって測定される粒子の円相当径の個数基準の粒度分布を表５及び表６にそれぞれ示し、粒度分布図を図１及び図２にそれぞれ示す。
【０１７７】
＜比較例１＞
実施例１と同様にしてトナー粒子（重量平均粒径７．５２μｍ、体積平均粒径６．４０μｍ、２．００〜３．１７μｍの粒子が７．９個数％、１．００μｍ以上２．００μｍ未満の粒子が０．４個数％）を得、チタン酸ストロンチウムの代わりに比較用酸化チタン１．０部を使用する以外は同様にして、表３の比較例１に示したような静電荷像現像用トナーを得た。
【０１７８】
＜比較例２＞
実施例１と同様にしてトナー粒子（重量平均粒径１１．３２μｍ、体積平均粒径９．４９μｍ、２．００〜３．１７μｍの粒子が０．２個数％、１．００μｍ以上２．００μｍ未満の粒子が１．２個数％）を得、チタン酸ストロンチウムＩを使用しない以外は同様にして、表３の比較例２に示したような静電荷像現像用トナーを得た。
【０１７９】
＜比較例３＞
実施例１と同様にしてトナー粒子（重量平均粒径５．７１μｍ、体積平均粒径４．９３μｍ、２．００〜３．１７μｍの粒子が１５．４個数％、１．００μｍ以上２．００μｍ未満の粒子が１．８個数％）を得、チタン酸ストロンチウムＩの代わりに比較用乾式シリカ１．０部を使用する以外は同様にして、表３の比較例３に示したような静電荷像現像用トナーを得た。
【０１８０】
＜比較例４＞
実施例１と同様にしてトナー粒子（重量平均粒径５．８５μｍ、体積平均粒径５．０２μｍ、２．００〜３．１７μｍの粒子が１５．１個数％、１．００μｍ以上２．００μｍ未満の粒子が４．３個数％）を得、比較用チタン酸ストロンチウム１．０部を使用する以外は同様にして、表３の比較例４に示したような静電荷像現像用トナーを得た。
【０１８１】
次にこれらの調製されたトナーを以下に示すような方法によって評価した。図３に示す画像形成装置として、市販のレーザービームプリンターＬＢＰ−４５０（キヤノン製）を用い、プリント速度１２枚（Ａ４）／１分を２０枚（Ａ４）／１分に改造し、低温低湿下（１０℃・１５％ＲＨ）及び高温高湿下（３２．５℃・９０％ＲＨ）のそれぞれの環境下で３万枚（３０Ｋ）のプリントアウト試験を行った。トナー切れに際しては、カートリッジ上部のトナー容器部分に切り込みを設け、そこからトナーを補給することによってプリントアウト試験を続けた。得られた画像を下記の項目について評価した。
【０１８２】
（１）ドット再現性
高温高湿環境での耐久初期と３０Ｋ耐久後の画像で、独立した１ドットのパターンをプリントアウトし、１ドットの再現性を顕微鏡観察によって評価した。
Ａ：非常に良好（ドットを忠実に再現しており、トナー飛散もほとんど無い）
Ｂ：良好（ドットを忠実に再現している）
Ｃ：普通（やや像に汚れがある）
Ｄ：悪い（像に乱れが多く再現性が悪い）
【０１８３】
（２）画像濃度
高温高湿環境では耐久初期と３０Ｋ耐久後の画像で、低温低湿環境では３０Ｋ耐久後の画像で通常の複写機用普通紙（７５ｇ／ｍ²）にプリントアウト時の画像濃度により評価した。なお、画像濃度は「マクベス反射濃度計」（マクベス社製）を用いて、原稿濃度が０．００の白地部分のプリントアウト画像に対する相対濃度を測定した。
【０１８４】
（３）カブリ
リフレクトメーター（東京電色（株）製）により測定した転写紙の白色度と、低温低湿環境下での３万枚（３０Ｋ）プリントアウト後のベタ白画像の白色度との比較からカブリを算出した。
【０１８５】
以上（１）〜（３）の評価結果を表４に示した。
【０１８６】
【表２】

【０１８７】
【表３】

【０１８８】
【表４】

【０１８９】
【表５】

【０１９０】
【表６】

【０１９１】
【発明の効果】
本発明によれば、高温高湿の環境で長期にわたる耐久を行ってもトナーの帯電量の低下がなく、画像濃度の低下や画質の劣化も起らず、ドット再現性に優れた画像を得ることができる。
【図面の簡単な説明】
【図１】本発明の実施例１２で調製したトナーのフロー式粒子像分析装置によって測定される粒子の円相当径の個数基準の粒度分布図を示す。
【図２】本発明の実施例１２で外添剤微粒子を外添する前のトナー粒子のフロー式粒子像分析装置によって測定される粒子の円相当径の個数基準の粒度分布図を示す。
【図３】本発明の実施例に用いた画像形成装置の概略的説明図を示す。
【図４】本発明のプロセスカートリッジの一実施例を示す説明図である。
【図５】本発明の画像形成方法をファクシミリのプリンターに適用した場合のブロック図である。
【符号の説明】
１ 現像装置
２ 現像剤容器
３ 感光体
４ 転写手段
５ レーザー光又はアナログ光
６ トナー担持体
７ クリーニングブレード
８ 規制ブレード
１１ 帯電手段
１２ バイアス印加手段
１３ 現像剤
１４ クリーニング手段
１５ 磁界発生手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic image developing toner for developing an electrostatic image such as electrophotography and electrostatic printing, an image forming method using the toner, and a process cartridge.
[0002]
[Prior art]
Conventionally, a number of methods are known as electrophotographic methods. In general, an electric latent image is formed on a photoreceptor by various means using a photoconductive substance, and the latent image is formed with toner. Development is performed to make a visible image (toner image), and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed to the transfer material by heat and / or pressure to obtain a fixed image It is.
[0003]
In recent years, image forming apparatuses using electrophotography have been applied to various apparatuses such as printers and facsimiles in addition to conventional copying machines. LED or LBP printers are the mainstream in the recent market as printer devices, and the direction of technology is higher resolution, that is, what was conventionally 240, 300 dpi is 400, 600, 1200 dpi. Accordingly, with this development, higher definition has been demanded. Copiers are also becoming more sophisticated, and are therefore moving toward digitalization. In this direction, the method of forming an electrostatic charge image with a laser is the main method, so it is also proceeding in the direction of high resolution, and here again, a high-resolution and high-definition development method has been demanded as with printers. JP-A-1-112253 and JP-A-2-284158 propose a toner having a small particle diameter.
[0004]
However, the durability of toner is still not sufficient for the recent increase in speed and life of copying machines and printers, and image density and resolution will decrease if used for a long time in high-temperature and high-humidity environments. Thus, problems due to toner degradation are likely to occur.
[0005]
Japanese Patent Laid-Open No. 8-278659 (corresponding European Patent Publication No. 0727717) discloses a toner for developing an electrostatic charge image in which the weight average particle diameter of the toner and the ratio of toner particles having a particle diameter of 3.17 μm or less are defined. Is described. In JP-A-8-278659, it is possible to form a good high-quality image by defining the content ratio of toner particles having a particle size of 3.17 μm or less with respect to the weight average particle size of the toner. Although effective, the particles having a particle diameter of less than 2 μm are not particularly considered, and therefore it is desired to further improve the durability of a large number of sheets particularly in a high temperature and high humidity environment.
[0006]
JP-A-6-67458 (corresponding US Pat. No. 5,406,357) discloses a magnetic toner having a binder resin component having a specific molecular weight distribution, and silica fine powder, metal oxide powder and fluorine-containing resin powder as additives. It has been disclosed with regard to a developer for developing an electrostatic charge image that has a specific ratio, suppresses toner fusion to the contact charging member and the contact transfer member, and has excellent low-temperature fixability and offset resistance.
[0007]
European Patent Publication No. 0762223 describes a toner for developing an electrostatic charge image in which the development stability and the durability of a large number of sheets are increased by having particles containing a specific composite oxide.
[0008]
JP-A-6-3854 discloses a developer containing magnetic toner, a fluidizing agent, and a metal oxide powder having a specific particle size distribution as a developer for use in a specific image forming apparatus.
[0009]
However, in these publications, when the weight average particle diameter of the toner is made smaller for the purpose of forming a high-quality image excellent in dot reproducibility, the content ratio of particles having a particle diameter of less than 2.0 μm in the toner is set. In order to form a high-quality image until after the endurance of a large number of sheets in a high-temperature and high-humidity environment, further improvement is desired.
[0010]
Thus, the toner performance improvement is still insufficient, and many points to be improved remain.
[0011]
[Problems to be solved by the invention]
The object of the present invention is to output images with high image density, low fog (toner development on non-image areas), and high resolution and high definition images over a long period of time under high and high humidity and low and low humidity environments. It is an object of the present invention to provide a toner for developing an electrostatic charge image, an image forming method using the toner, and a process cartridge.
[0012]
[Means for Solving the Problems]
The present invention relates to an electrostatic charge image developing toner having toner particles containing at least a binder resin and a colorant, and external additive fine particles.
The toner is
(I) The weight average particle diameter (D) of the toner in a value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter._FourX μm) and the Y number% of the content of particles having a particle size of 2.00 to 3.17 μm are the following conditions (1) and (2):
−5X + 35 ≦ Y ≦ −25X + 180 (1)
3.5 ≦ X ≦ 6.5 (2)
A particle size distribution satisfying
(Ii) Inclusion of particles having an equivalent circle diameter of 1.00 μm or more and less than 1.03 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by a flow particle image analyzer The A number% of the amount and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (3):
B−A ≦ 0.30 (3)
Particle size distribution that satisfies
The present invention relates to a toner for developing an electrostatic charge image.
[0013]
The present invention also provides a charging step of charging an electrostatic latent image carrier for carrying an electrostatic latent image;
An electrostatic latent image forming step of forming an electrostatic latent image on a charged electrostatic latent image carrier; and
A developing step of developing the electrostatic latent image of the electrostatic latent image carrier with toner to form a toner image;
In an image forming method having
The present invention relates to an image forming method, wherein the toner for developing an electrostatic charge image is used as the toner.
[0014]
Furthermore, the present invention provides a process cartridge that is detachably attached to the image forming apparatus main body.
The process cartridge includes: (i) an electrostatic latent image carrier for carrying an electrostatic latent image; and (ii) a toner image by developing the electrostatic latent image carried on the electrostatic latent image carrier. A developing means holding toner for forming
The toner has toner particles containing at least a binder resin and a colorant, and external additive fine particles,
The present invention relates to a process cartridge in which the toner for developing an electrostatic charge image is used as the toner.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
One of the characteristics of the toner for developing an electrostatic charge image of the present invention is the weight average diameter (D_Four) Is X (μm) and the ratio of particles having a particle size of 2.00 μm to 3.17 μm in the toner number distribution is Y (number%), Y is −5X + 35 ≦ Y ≦ −25X + 180 (preferably −5X + 35). ≦ Y ≦ −12.5X + 98.75) and X has a particle size distribution satisfying 3.5 ≦ X ≦ 6.5 (preferably 4.0 ≦ X ≦ 6.3). The toner having such a particle size distribution has a high image density, can form a high resolution / high definition image with no fog and excellent dot reproducibility.
[0016]
Weight average diameter of toner (D_Four) When X (μm) is smaller than 3.5 μm, the toner is likely to be charged up, and the image density is likely to decrease. When X (μm) is larger than 6.5 μm, the dot reproducibility is poor, which is not preferable. When the ratio Y (number%) of particles having a particle diameter of 2.00 μm to 3.17 μm in the toner number distribution is smaller than −5X + 35, the dot reproducibility is inferior as in the case where X (μm) is larger than 6.5 μm. It is not preferable. When Y (number%) is larger than −25X + 180, fog is increased, which is not preferable.
[0017]
That is, in the present invention, in order to form a higher resolution / high definition image, the weight average particle diameter (D_Four) Is reduced, the weight average particle diameter (D_FourThe content of particles having a particle diameter of 2.00 μm to 3.17 μm contained in the toner is defined so as to be an optimum value.
[0018]
However, as a result of intensive studies by the present inventors, even if the toner has the particle size distribution as described above, the fluidity and charge amount of the toner are reduced when the toner is endured for a long time in a high temperature and high humidity environment. It was found that there was a deterioration in image quality and a decrease in image density.
[0019]
As a result of investigating the cause, a particle size of less than 2.00 μm, which cannot be measured by the above-described apparatus for measuring the toner particle size, such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.), was used. The influence of fine particles was confirmed, and it was found that these fine particles can be measured by a flow type particle image analyzer. This is because the flow particle image analyzer measures the particle size 2 of the toner particles and the external additive fine particles while the device such as the Coulter Counter TA-II type or the Coulter Multisizer measures toner particles having a particle size of 2.00 μm or more. This is because fine particles of less than 0.000 μm can be measured.
[0020]
An electrostatic charge image developing toner that does not decrease the charge amount of the toner even if it is durable for a long time in a high temperature and high humidity environment, and does not cause a decrease in image density or image quality. In order to obtain, in addition to the toner having the above specific particle size distribution, in the particle size distribution based on the number of particles of 0.60 μm to 159.21 μm measured by a flow particle image analyzer, the equivalent circle diameter The content A (number%) of particles having a particle diameter of 1.00 μm or more and less than 1.03 μm and the content B (number%) of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are B−A ≦ 0.30. It is important that the particle size distribution satisfy −0.63 ≦ B−A ≦ 0.30.
[0021]
Further, in the present invention, in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm to 159.21 μm measured by a flow type particle image analyzer, the equivalent circle diameter is 1.00 μm or more and less than 2.00 μm. The particle content C (number%) is preferably 10 number% or more, more preferably 10 to 37.7 number%.
[0022]
Although it is not clear about the mechanism of the effect by controlling the content ratio of fine particles that can be analyzed by this flow type particle image analyzer, the following reasons are presumed. When durability is performed for a long time in a high-temperature and high-humidity environment, external additive particles such as silica fine particles existing on the toner particle surface are embedded in the toner particle surface, or the convex portion of the toner particle is missing. Means that the surface state of the toner particles changes and the fluidity and chargeability are likely to decrease. However, by controlling the fine particles to satisfy a certain content ratio, the developing sleeve and the regulating blade The load applied to the toner when contacting with the toner charging member such as the toner is reduced, and external additive particles such as silica fine particles existing on the toner particle surface are embedded in the toner particle surface. It is thought that the lack of a convex part etc. is prevented.
[0023]
In particular, it seems that the effect of preventing the deterioration of toner particles having a particle size of 2.00 μm to 3.17 μm, which has a high charge amount and a large influence on image quality such as dot reproducibility, is considered to be great.
[0024]
That is, in order to form a high-resolution and high-definition image excellent in dot reproducibility, the weight average particle diameter of the toner is small, and particles having a particle diameter of 2.00 μm to 3.17 μm are used as the weight average particle diameter of the toner. It is necessary to contain a specific amount corresponding to this, but the particles having a particle size of 2.00 to 3.17 μm have a large specific surface area per unit weight, so that the triboelectric charge amount per unit weight (μC / g) increases. Therefore, it has a high electrostatic attractive force to a toner carrier such as a carrier and a developing sleeve, and is easily subjected to a strong load, so that it is easy to cause a lack of convex portions of toner particles and embedding of external additive particles such as silica fine particles. In addition, when ultrafine particles having a primary average particle size of 20 mμ or less such as silica particles adhere to the surface of the toner particles, as described above, particles having a particle size of 2.00 μm to 3.17 μm have a particle size of 3. Since the specific surface area per unit weight is larger than that of particles larger than 17 μm, the amount of ultrafine particles deposited per unit weight is increased, so that the particles are easily affected by external additive particles.
[0025]
Therefore, the toner whose particle size distribution by the Coulter counter satisfies the above-mentioned specific condition satisfies the above-mentioned specific condition by the particle size distribution of the equivalent circle diameter by the flow type particle image analyzer. The performance of toner that can form high-resolution and high-definition images with reduced image quality, high image density, no fog, and excellent dot reproducibility over a long period of time in harsh environments such as high temperature and high humidity. It is possible to maintain.
[0026]
In the case of B-A> 0.30, a sufficient effect cannot be obtained in combination with toner particles having a particle size distribution used in the present invention, and a decrease in image density and a deterioration in image quality are extremely preferable during long-term durability. Absent.
[0027]
In the case of B−A <−0.63, the number of particles having a small equivalent circle diameter increases, so that a charge-up phenomenon in which a decrease in image density occurs due to an excessive charge amount is likely to occur.
[0028]
Further, when the content C of particles having the equivalent circle diameter of the toner of 1.00 μm or more and less than 2.00 μm is less than 10% by number, the effect of reducing the load of the toner particles due to the external additive fine particles is not sufficiently exhibited. .
[0029]
As a method for satisfying these particle size distributions, fine particles A having a circle-equivalent mean diameter of 0.60 to 4.00 μm in the number-based particle size distribution by a flow particle image analyzer are used as toner particles and a Henschel mixer. It is the simplest and preferable to stir and mix using a simple mixer.
[0030]
Fine particles A having an equivalent circle average diameter of 0.60 to 4.00 μm (preferably 1.00 to 4.00 μm, more preferably 1.00 to 3.00 μm) are toners having a particle diameter of 2.00 to 3.17 μm. Since the particle size is close to that of the particle, it tends to behave similarly in the developing unit. As a result, since the load received by the toner particles having a particle diameter of 2.00 to 3.17 μm is dispersed also in the fine particles A during long-term durability, it is considered that toner deterioration can be suppressed.
[0031]
Further, the external additive fine particles A having an equivalent circle average diameter of 0.60 to 4.00 μm that can be used in the present invention have an equivalent circle diameter in the number-based particle size distribution by a flow type particle image analyzer. The content a (number%) of particles of 1.00 μm or more and less than 1.03 μm and the content b (number%) of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are preferably as follows:
b−a ≦ 0.30
It is good to satisfy, more preferably the following conditions
−0.63 ≦ b−a ≦ 0.30
It is good to satisfy, more preferably the following conditions
−0.51 ≦ b−a ≦ 0.30
Good to meet.
[0032]
When ba-> 0.30, the external additive fine particles A contain a large number of particles having a relatively large particle size, and the behavior of these fine particles in the developing device is 2.00 to 2,000. This is different from the behavior of 3.17 μm toner particles, and the effect of preventing toner deterioration is small.
[0033]
In the case of ba <−0.63, many particles having a small particle diameter are included, and a charge-up phenomenon or the like is likely to occur.
[0034]
As the external additive fine particles to be mixed with the toner particles, examples of the external additive fine particles A having an equivalent circle diameter of 0.5 μm to 4.0 μm include the following. These are preferably used alone or in combination. Metal oxide particles such as magnesium oxide, zinc oxide, aluminum oxide, cerium oxide, cobalt oxide, iron oxide, zirconium oxide, chromium oxide, manganese oxide, strontium oxide, tin oxide and antimony oxide; calcium titanate, magnesium titanate and Composite metal oxide particles such as strontium titanate; metal salt particles such as calcium carbonate, magnesium carbonate, aluminum carbonate, barium sulfate, calcium sulfate, aluminum sulfate and magnesium sulfate; clay mineral particles such as kaolin; phosphate compounds such as apatite Particles; silicon compound particles such as silica, silicon carbide and silicon nitride; carbon compound particles such as carbon black and graphite; epoxy resin, phenol resin, polyamide resin, silicone resin, silicone resin Resin particles such as urethane, melamine-formaldehyde, acrylic resin and fluororesin (Teflon, polyvinylidene fluoride); organic compounds such as rubber, wax, fatty acid compounds, resins and metals, metal oxides, salts, carbon black, etc. Composite particles with inorganic compounds; Fluorine inorganic compounds such as carbon fluoride; Fatty acid metal salts such as zinc stearate; Fatty acid derivative particles such as fatty acids and fatty acid esters; Lubricant particles such as molybdenum sulfide, amino acids and amino acid derivatives.
[0035]
Among these, zinc oxide, aluminum oxide, titanium oxide, zirconium oxide, manganese oxide, strontium titanate, magnesium titanate, and barium titanate are preferably used.
[0036]
These external additive fine particles A have a circle-equivalent mean diameter of 0.60 to 4.00 μm (preferably 1.00 to 4.00 μm, more preferably 1.30 μm) in a number-based particle size distribution by a flow particle image analyzer. It is preferable that the equivalent circle diameter is 1.00 μm or more and less than 1.03 μm, and the equivalent particle diameter is 2.00 μm or more and less than 2.06 μm. The particle content b (number%) is as follows:
b−a ≦ 0.30
It is preferable to use a powder whose particle size distribution has been adjusted in advance such as pulverization and classification so as to satisfy the above. In particular, the classification method is preferably a wet classification method using sedimentation separation such as centrifugation or thickener.
[0037]
Further, the toner particles before mixing the external additive fine particles A have a content of particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in a number-based particle size distribution by a flow particle image analyzer of 10% by number. It is more preferable to control the particle size distribution so as to be less than the above. If the number of toner particles is 10% by number or more in the range where the equivalent circle diameter is 1.00 μm or more and less than 2.00 μm, the effect of preventing toner deterioration is reduced even if fine particles are added.
[0038]
In particular, the toner of the present invention has a weight average diameter (D_Four) Is X (μm), and the ratio of toner particles having a particle size of 3.17 μm or less in the toner number distribution is Y (number%), the following conditions:
−5X + 35 ≦ Y ≦ −25X + 180
3.5 ≦ X ≦ 6.5
However, it is difficult to remove toner particles having a particle size of less than 2.00 μm by simply performing classification as in the conventional toner. For this reason, it is preferable to perform a more precise classification operation than in the past to remove toner particles of less than 2.00 μm as much as possible. For example, it is possible to classify a plurality of times with an air classifier such as an elbow jet, or to perform fine powder cut classification with a turbo classifier after classification with an elbow jet.
[0039]
In other words, in the present invention, by performing a precise classification operation, the particle size distribution is adjusted so that the content of toner particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm is 10% by number or less. A toner obtained by adding fine particles having a specific particle size distribution is preferred.
[0040]
Further, in the present invention, the volume average particle diameter (Dv) of the toner is preferably 2.5 μm to 6.0 μm. When the volume average particle diameter (Dv) is less than 2.5 μm, it is difficult to obtain a sufficient image density. When the volume average particle diameter (Dv) is larger than 6.0 μm, it is difficult to form a higher definition image.
[0041]
In the present invention, the measurement of the particle size distribution using a Coulter counter and the measurement of the particle size distribution using a flow type particle image analyzer are performed according to the following method.
[0042]
The average particle size and particle size distribution of the toner are measured using a Coulter Counter TA-II type (manufactured by Coulter), but it is also possible to use a Coulter Multisizer (manufactured by Coulter). As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of toner particles of 2.00 μm or more are measured by using the measuring apparatus with a 100 μm aperture as the volume. Distribution and number distribution were calculated. Then, a weight-based weight average particle diameter (D_Four), Volume average particle diameter (Dv) (respectively, the median value of each channel is a representative value for each channel), and a ratio of 2.00 μm to 3.17 μm based on the number obtained from the number distribution.
[0043]
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Use 13 channels less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm.
[0044]
The measurement of toner, toner particles and external additive fine particles A by a flow type particle image analyzer can be performed using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics Co., Ltd.
[0045]
The measurement removes fine debris through a filter and results in 10^-3cm^ThreeA few drops of a surfactant (preferably an alkylbenzene sulfonate) are added to 50 ml of water having a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in water of 20 or less, 2 to 20 mg of a measurement sample is added, and the dispersion treatment is performed for about 1 to 3 minutes with an ultrasonic disperser.^-3cm^ThreeThe particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm is measured using a sample dispersion liquid prepared for (measurement circle-equivalent diameter range).
[0046]
The outline of the measurement is described in the catalog (June 1995 edition) of FPIA-1000 published by Toa Medical Electronics Co., Ltd., the operation manual of the measuring apparatus, and JP-A-8-136439. It is.
[0047]
The sample dispersion is passed through a flat and flat transparent flow cell (thickness: about 200 μm) flow path (spread along the flow direction). The strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other so as to form an optical path that passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.
[0048]
In about 1 minute, the equivalent circle diameter of 1200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. In particular, the particle concentration of the example is 6000 particles / 10.^-3cm^ThreeIn the case of this toner dispersion, about 1800 equivalent circle diameters can be measured in about 1 minute.
[0049]
As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels for one octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.
[0050]
[Table 1]

*) The upper limit of the particle size range does not include the numerical value and represents “less than”.
[0051]
Furthermore, in the present invention, it is preferable that the void ratio when tapping the toner defined by the following formula is in the range of 0.45 to 0.70, and more preferably in the range of 0.50 to 0.70. Excellent chargeability.
Porosity = (true density−tap density) / true density
[0052]
The toner is triboelectrically charged mainly packed between the toner carrier and the toner regulating blade. Therefore, the degree of the toner packing state greatly affects the charging of the toner. When the toner has a porosity in the above range, the charging opportunity of each toner particle becomes uniform, so that the variation in the charge amount of each toner particle is controlled, and the image density and fog can be adjusted at a high level.
[0053]
In the present invention, the toner tap density is measured using a powder tester manufactured by Hosokawa Micron Co., Ltd., using a container attached to the powder tester, and the value measured according to the procedure of the instruction manual of the powder tester. say.
[0054]
In the present invention, the true density of the toner is measured as follows. 1 g of toner is put into an IR measurement tablet molding machine and about 1.96 MPa (200 kgf / cm²) At a pressure of 1 minute for 1 minute. The volume and weight of this sample are measured to determine the true density.
[0055]
The binder resin used in the present invention includes polystyrene, poly-P-chlorostyrene, and a homopolymer of styrene such as polyvinyltoluene; and styrene-P-chlorostyrene copolymer, styrene-vinyl. Toluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, Styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer and styrene-acrylonitrile-indene copolymer Styrene copolymer such as poly Phenolic resin; natural modified phenolic resin; natural resin modified maleic acid resin; acrylic resin such as polyacrylic acid and polyacrylic acid ester; methacrylic resin such as polymethacrylic acid and polymethacrylic acid ester; polyvinyl acetate; Polysilicone resin; Polyurethane resin; Polyurethane resin; Epoxy resin; Xylene resin; Polyvinyl butyral; Terpene resin; Coumarone indene resin; Petroleum resin can be used. Further, a crosslinked styrene resin is also a preferable binder resin.
[0056]
As a comonomer with respect to the styrene monomer of a styrene-type copolymer, a vinyl-type monomer can be used individually or in combination. Examples of vinyl monomers include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, and methyl methacrylate. , Monocarboxylic acids having a double bond such as ethyl methacrylate, butyl methacrylate, octyl methacrylate and acrylamide or substituted products thereof; for example, double bonds such as maleic acid, butyl maleate, methyl maleate and dimethyl maleate Dicarboxylic acids having the following substituents; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; for example vinyl methyl ketone and vinyl hexene. Such vinyl ketones of ketone; for example, vinyl methyl ether, such as vinyl ethers of vinyl ethyl ether and vinyl isobutyl ether.
[0057]
Here, as the crosslinking agent, compounds having two or more polymerizable double bonds are used alone or in combination. Examples of such compounds include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate. Carboxylic acid esters; divinyl aniline, divinyl ether, divinyl compounds such as divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups.
[0058]
Examples of the polymerization method of the high molecular weight component of the resin composition according to the present invention include an emulsion polymerization method and a suspension polymerization method.
[0059]
Among them, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed as small particles in an aqueous phase with an emulsifier, and polymerization is performed using a water-soluble polymerization initiator. In this method, the reaction heat can be easily adjusted, and the termination reaction rate is low because the phase in which the polymerization is carried out (the oil phase consisting of the polymer and the monomer) and the aqueous phase are separate, resulting in a high polymerization rate. A product having a high degree of polymerization is obtained. Furthermore, the reason is that the polymerization process is relatively simple, and that the polymerization product is fine particles, so that it can be easily mixed with colorants, charge control agents and other additives in the production of toner. Therefore, there is an advantage as a method for producing a binder resin for toner.
[0060]
However, the added polymer is likely to be impure due to the added emulsifier, and an operation such as salting out is necessary to take out the polymer. Suspension polymerization is convenient to avoid this inconvenience.
[0061]
In suspension polymerization, it is good to carry out by 100 weight part or less (preferably 10-90 weight part) of monomers with respect to 100 weight part of aqueous solvents. Examples of the dispersant that can be used include polyvinyl alcohol, partially saponified polyvinyl alcohol, and calcium phosphate. The amount of the dispersant used is an appropriate amount of monomer based on the aqueous solvent, but generally 0.05 to 1 part by weight is used with respect to 100 parts by weight of the aqueous solvent. The polymerization temperature is suitably 50 to 95 ° C., but should be appropriately selected depending on the initiator used and the target polymer.
[0062]
As a method for synthesizing the low molecular weight component of the binder resin according to the present invention, a known method can be used. However, the bulk polymerization method has a problem that it is difficult to control the reaction, although it is possible to obtain a low molecular weight polymer by polymerizing at a high temperature to stop the termination reaction rate. In that respect, in the melt polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer by a solvent or by adjusting the amount of initiator and reaction temperature. It is preferable when synthesizing a low molecular weight substance. In particular, in order to highly control the acid component and molecular weight, for example, a method of obtaining a low molecular weight polymer by mixing polymers having different molecular weights and compositions, or a method of adding monomers having different compositions later is used. Can do.
[0063]
As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol, benzene and the like are used. In the case of a styrene monomer mixture, xylene, toluene or cumene is preferred. It is appropriately selected depending on the polymer to be polymerized.
[0064]
In the present invention, it is preferable that the toner contains a wax if necessary. Examples of the wax used include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, and carnauba wax and derivatives thereof. The derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products with vinyl monomers.
[0065]
The wax preferably used in the present invention is represented by the following general formula.
[0066]
RY
[0067]
In the formula, R represents a hydrocarbon group,
Y represents hydrogen, a hydroxyl group, a carboxyl group, an alkyl ether group, an ester group or a sulfonyl group.
[0068]
The compound represented by the above RY has a weight average molecular weight (Mw) by GPC of 3000 or less, preferably 500 to 2500.
[0069]
Specific examples of the compound include compounds represented by the following formulas (A), (B) and (C).
(A) CH_Three(CH₂)_nCH₂OH (n = 20 to 300)
(B) CH_Three(CH₂)_nCH₂COOH (n = 20-300)
(C) CH_Three(CH₂)_nCH₂OCH₂(CH₂)_mCH_Three
(N = 20-200, m = 0-100)
These compounds are derivatives of the compound (A), and the main chain is a linear saturated hydrocarbon. Any compound other than those shown in the above examples can be used as long as it is a compound derived from compound (A). By using the wax, the toner of the present invention can highly satisfy the fixing property at a low temperature and the offset resistance at a high temperature.
[0070]
Among the above compounds, a wax using as a main component a polymer alcohol represented by the above formula (A) is preferable. The above wax has a good sliding property and is particularly excellent in offset resistance.
[0071]
In the present invention, the molecular weight distribution of the wax is measured under the following conditions by GPC (gel permeation chromatography).
[0072]
<GPC measurement conditions for wax>
Apparatus: GPC-150C (manufactured by Waters)
Column: Duplex of GMH-HT (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% ionol added)
Flow rate: 1.0 ml / min.
Sample: 0.4 ml of 0.15 wt% sample was injected
[0073]
Measurement is performed under the above conditions, and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used in calculating the molecular weight of the sample. Furthermore, it calculates by converting with the conversion formula derived | led-out from the Mark-Houwink viscosity formula.
[0074]
These waxes are preferably used in an amount of 0.5 to 20 parts by weight with respect to 100 parts by weight of the binder resin.
[0075]
The toner is preferably used as a magnetic toner containing a magnetic substance as a colorant. The magnetic toner content of the magnetic toner is 30 to 200 parts by weight, preferably 50 to 150 parts by weight, with respect to 100 parts by weight of the binder resin.
[0076]
In the present invention, it is more preferable to add a negative charge control agent to the toner to obtain a negative charge magnetic toner.
[0077]
Specific examples of negative charge control agents include metal complexes of monoazo dyes described in JP-B Nos. 41-20153, 42-27596, 44-6397, and 45-26478; Nitroamic acid and salts thereof described in JP-A-50-133338; I. Dyes and pigments such as 14645; salicylic acid, naphthoic acid, dicarboxylic acid described in JP-B-55-42752, JP-B-58-41508, JP-B-58-7384 and JP-B-59-7385 Metal complexes such as Zn, Al, Co, Cr and Fe; sulfonated copper phthalocyanine pigments; styrene oligomers introduced with nitro groups and halogens; and chlorinated paraffins. In particular, an azo metal complex represented by the general formula (I) and a basic organic acid metal complex represented by the general formula (II) that are excellent in dispersibility and effective in reducing the image density stability and fogging are preferred.
[0078]
[Chemical 1]

[0079]
[Chemical 2]

[0080]
Among them, the azo metal complex represented by the above formula (I) is more preferable, and the azo iron complex represented by the following formula (III) in which the central metal is Fe is most preferable.
[0081]
[Chemical 3]

[0082]
Next, specific examples of the azo iron complex represented by the above formula (III) are shown below.
[0083]
[Formula 4]

[0084]
[Chemical formula 5]

[0085]
In the present invention, the content of the charge control agent is preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the binder resin. When the content of the charge control agent is excessive, the fluidity of the toner is deteriorated and fog is likely to occur. When the content is too small, it is difficult to obtain a sufficient charge amount.
[0086]
In the toner of the present invention, an inorganic fine powder B such as a hydrophilic inorganic fine powder or a hydrophobic inorganic fine powder is used as external additive particles in order to improve environmental stability, charging stability, developability, fluidity, and storage stability. It is preferable to mix with toner particles together with the fine particles A described above. Examples of the inorganic fine powder B include silica fine powder, titanium oxide fine powder, and hydrophobized products thereof. They are preferably used alone or in combination.
[0087]
As the silica fine powder, both a so-called dry method produced by vapor phase oxidation of a silicon halide compound or a dry silica called fumed silica and a so-called wet silica produced from water glass or the like can be used. And there are few silanol groups inside, and Na₂O, SO_Three ^2-Dry silica having no production residue such as is preferred. In dry silica, it is possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.
[0088]
Further, the silica fine powder is preferably hydrophobized. The hydrophobizing treatment is applied by chemically treating with a treating agent that reacts or physically adsorbs with silica fine powder such as an organosilicon compound. As a preferable method, a dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane coupling agent or with a silane coupling agent and simultaneously with an organosilicon compound such as silicone oil. Is mentioned.
[0089]
Examples of silane coupling agents used for hydrophobizing treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allylphenyldichlorosilane. , Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyl Tetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one silicon atom at each terminal unit Examples include siloxane.
[0090]
Examples of the organosilicon compound include silicone oil. As a preferable silicone oil, one having a viscosity at 25 ° C. of about 30 to 1,000 centistokes is used. Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.
[0091]
Silicone oil treatment can be performed by, for example, mixing silica fine powder treated with a silane coupling agent and silicone oil directly using a mixer such as a Henschel mixer, or injecting silicone oil onto the base silica. Depending on how you do it. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, the base silica fine powder may be mixed to remove the solvent.
[0092]
The average particle size of the inorganic fine powder is preferably 0.002 to 0.2 μm as the primary particle size from the viewpoint of improving charging stability and fluidity.
[0093]
Further, in the present invention, in order to prevent the transfer from being lost or the toner from being fused to the photosensitive drum, the fine particle aggregate C containing 20 to 90% by weight of silicone oil or silicone varnish is mixed as external additive fine particles. It is more preferable.
[0094]
In the present invention, as the fine particles used in the fine particle aggregate C composed of fine particles and silicone oil or silicone varnish, inorganic compound fine particles or organic compound fine particles are used. Examples of the organic compound include resin particle aliphatic compounds such as styrene resin, acrylic resin, silicone resin, silicone rubber, polyester resin, urethane resin, polyamide resin, polyethylene resin, and fluorine resin.
[0095]
Inorganic compounds include SiO₂, GeO₂, TiO₂, SnO₂, Al₂O_Three, B₂O_Three, P₂O_Five, As₂O_ThreeMetal oxides such as: silicate, borate, phosphate, germanate, borosilicate, aluminosilicate, aluminoborate, aluminoborosilicate, tungstate, molybdate, tellurate Metal oxide salts such as: and composite compounds thereof; silicon carbide, silicon nitride, amorphous carbon. These may be used alone or in combination.
[0096]
Among these, metal oxides are preferably used, and metal oxides or composite compounds selected from the group consisting of Si, Al, and Ti are more preferable. You may use what hydrophobized the surface beforehand with the coupling agent.
[0097]
The silicone oil used in the present invention is represented by the following general formula (IV)
[0098]
[Chemical 6]

[0099]
R: C1-C3 alkyl group
R ': from alkyl, halogen-modified alkyl, phenyl and modified phenyl
Silicone oil modified group selected from the group
R ″: an alkyl or alkoxy group having 1 to 3 carbon atoms
Is preferred. Examples thereof include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil.
[0100]
In the present invention, an amino-modified silicone oil having a structure represented by the formula (V) can also be used as the silicone oil.
[0101]
[Chemical 7]

[0102]
(Where R_ThreeAnd R₈Represents hydrogen, an alkyl group, an aryl group or an alkoxy group, and R_FourRepresents an alkylene group or a phenylene group, and R_FiveRepresents a compound having a nitrogen-containing heterocyclic ring in its structure, and R₆And R₇Represents hydrogen, an alkyl group or an aryl group, R_FourIs not necessary. However, the above alkyl group, aryl group, alkylene group and phenylene group may contain an amine, or may have a halogen as a substituent within a range not impairing the chargeability. p is a number of 1 or more, and q and r are positive numbers including 0. However, q + r is a positive number of 1 or more. )
[0103]
The most preferable structure among the above structures is one in which the number of nitrogen atoms in the side chain containing a nitrogen atom is 1 or 2.
[0104]
Examples of the unsaturated heterocyclic ring containing nitrogen are given below.
[0105]
[Chemical 8]

[0106]
An example of a saturated heterocyclic ring containing nitrogen is given below.
[0107]
[Chemical 9]

[0108]
However, the present invention is not limited to the above compound examples, but preferably has a 5-membered ring or a 6-membered heterocyclic ring.
[0109]
Examples of the derivatives include derivatives in which a hydrocarbon group, a halogen group, an amino group, a vinyl group, a mercapto group, a methacryl group, a glycidoxy group, or a ureido group is introduced into the above compound group.
[0110]
You may use these by 1 type, or 2 or more types of mixed systems.
[0111]
Examples of the silicone varnish used in the present invention include methyl silicone varnish and phenylmethyl silicone varnish, and methyl silicone varnish is particularly preferable.
[0112]
Methyl silicone varnish is T represented by the following structural formula³¹Unit, D³¹Unit, M³¹A polymer composed of units, and T³¹A three-dimensional polymer containing a large amount of units.
[0113]
[Chemical Formula 10]

[0114]
Specifically, the methylsilicone varnish or the phenylmethylsilicone varnish is a substance having a chemical structure represented by, for example, the following structural formula (VI).
[0115]
Embedded image

(R³¹Represents a methyl group or a phenyl group. )
[0116]
In the above silicone varnish, particularly T³¹The unit is an effective unit for imparting a good thermosetting property to a three-dimensional network structure. T above³¹The units are preferably contained in the silicone varnish in a proportion of 10 to 90 mol%, particularly 30 to 80 mol%.
[0117]
Such a silicone varnish has a hydroxyl group at the end or side chain of the molecular chain, and is cured by dehydration condensation of the hydroxyl group. Examples of the curing accelerator that can be used to accelerate the curing reaction include fatty acid salts such as zinc, lead, cobalt, and tin; amines such as triethanolamine and butylamine. Of these, amines can be preferably used.
[0118]
In order to use the silicone varnish as described above as an amino-modified silicone varnish, the T³¹Unit, D³¹Unit, M³¹A part of methyl group or phenyl group present in the unit may be substituted with a group having an amino group. Examples of the group having an amino group include those represented by the following structural formulas (VII) to (XI). However, it is not limited to these.
[0119]
Embedded image

[0120]
The silicone oil or silicone varnish has a viscosity at 25 ° C. of preferably 50 to 200,000 centistokes, more preferably 500 to 150,000 centistokes, more preferably 1,500 to 100,000 centistokes, and still more preferably. 3,000-80,000 centistokes is good.
[0121]
If it is less than 50 centistokes, it is difficult to form a large amount of silicone oil or silicone varnish into good particles, the fine particle aggregates are not stable, and the image quality tends to deteriorate due to heat and mechanical stress.
[0122]
When it exceeds 200,000 centistokes, it tends to be difficult to form a silicone oil or a silicone varnish.
[0123]
The viscosity of the silicone oil or the silicone varnish is measured using a Bisco Tester VT500 (manufactured by Harke).
[0124]
One of several viscosity sensors for VT500 is selected (optional), and a measurement sample is put in a measurement cell for the sensor and measured. The viscosity (Pas) displayed on the apparatus is converted to cSt (centistokes).
[0125]
The initial effect is obtained when the treatment amount of the silicone oil or the silicone varnish in the fine particle aggregate C is 20 to 90% by weight, preferably 27 to 85% by weight, more preferably 40 to 80% by weight.
[0126]
When the treatment amount of silicone oil or silicone varnish is less than 20% by weight, it is less effective for improving transfer dropout and toner fusion to the photosensitive drum. When it exceeds 90% by weight, the silicone oil or silicone varnish is used as particles. It becomes difficult to hold, and excessive silicone oil or silicone varnish causes toner particles to aggregate and easily deteriorates the image quality.
[0127]
The application amount of the fine particle aggregate C composed of silicone oil or silicone varnish and fine particles is preferably 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, further preferably 100 parts by weight of the toner. Is preferably 0.05 to 2 parts by weight. If the amount is less than 0.01 part by weight, the effect of improving transfer omission and toner fusion to the photosensitive drum is small. If the amount exceeds 10 parts by weight, the toner fixing property tends to be impaired.
[0128]
The fine particle aggregate C composed of silicone oil or silicone varnish and fine particles according to the present invention contains a relatively large amount of a silicone oil or silicone varnish having a good releasability of 20 wt% to 90 wt%. This works to improve the releasability between the toner and the photoreceptor surface.
[0129]
Silicone oil is more preferred than silicone varnish because it is easier to apply to the surface of the photoreceptor. The silicone oil preferably contains no alkoxy group.
[0130]
The average particle diameter of the fine particle aggregate C is preferably 0.5 to 50 μm from the viewpoint of uniform mixing in the toner.
[0131]
In the present invention, it is more preferable to add resin fine particles D as external additive particles to the toner in order to improve developability and fluidity.
[0132]
The resin fine particles D can be produced by adjusting the production conditions by emulsion polymerization or spray drying. Preferably, a glass transition point of 80 ° C. or higher obtained by homopolymerizing or copolymerizing components used in a binder resin for toner, such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, by an emulsion polymerization method. Resin particles show a good effect.
[0133]
It may be crosslinked with a crosslinking agent such as divinylbenzene, and the surface may be treated with a metal, a metal oxide, a pigment, a dye, or a surfactant.
[0134]
The resin fine particles D in the present invention are particularly preferably block or random styrene copolymers containing 51% by weight or more of styrene monomer units. The styrenic resin fine particles are usually close to the styrene-acrylic resin or polyester resin used for the binder resin of the toner, and are less charged with toner particles, so that the fluidity is hardly deteriorated.
[0135]
When the styrene monomer unit contained in the resin fine particles D is less than 51% by weight, toner cohesion becomes strong, fluidity is deteriorated, and image white spots and image density unevenness are likely to occur.
[0136]
The average particle diameter of the resin fine particles D is preferably 0.01 to 1.0 μm from the viewpoint of improving developability.
[0137]
The average particle size of the inorganic fine powder B, the fine particle aggregate C, and the resin fine particle D is a value measured by the following method.
[0138]
Using an electron microscope S-800 (manufactured by Hitachi, Ltd.), the inorganic fine powder B is photographed at a magnification of 100,000 to 200,000 times, the fine particle aggregate C is 100 to 2000 times, and the resin fine particle D is 10,000 to 20000 times. From the photographed fine particles, the inorganic fine powder B is random for particles having a particle size of 5 nm or more, the fine particle aggregate C is for particles having a particle size of 0.2 μm or more, and the resin fine particle D is random for particles of 0.005 μm or more. 100 to 200 samples were extracted, and each diameter was measured using a measuring instrument such as a caliper, and the averaged diameter was defined as the average particle diameter of each fine particle.
[0139]
A preferred specific example of the image forming method of the present invention will be described with reference to FIG.
[0140]
The surface of the OPC photosensitive drum 3 as an electrostatic latent image carrier is negatively charged by a contact charging member 11 comprising a charging roller as a primary charger, and a digital electrostatic latent image is obtained by image scanning by exposure 5 with a laser beam. The latent image is formed by a negative triboelectrically chargeable magnetic toner 13 of the developing device 1 as a developing means, which includes a developing sleeve 6 that includes an elastic blade 8 made of urethane rubber and a magnet 15 that are formed and installed in the counter direction. Reverse development. Alternatively, an amorphous silicon photoconductor is used, the photoconductor is positively charged, an electrostatic latent image is formed, and normal development is performed using a negative triboelectrically chargeable magnetic toner. An alternating bias, a pulse bias, and / or a direct current bias is applied to the developing sleeve 6 by the bias applying means 12. When the transfer paper P is conveyed and arrives at the transfer section, the contact transfer member 4 comprising a transfer roller as a transfer means charges the back surface of the transfer paper P (opposite to the photosensitive drum side), thereby charging the surface of the photosensitive drum. The toner image is electrostatically transferred onto the transfer paper P. The transfer paper P separated from the photosensitive drum 3 is subjected to a fixing process in order to fix the toner image on the transfer paper P by a heating and pressure fixing device having a heating roller 21 and a pressure roller 22 having heating means 20 inside. The
[0141]
The magnetic toner remaining on the photosensitive drum 3 after the transfer process is removed by a cleaning device 14 having a cleaning blade 7. The photosensitive drum 3 after cleaning is neutralized by the erase exposure 10 and the process starting from the charging process by the primary charger 11 is repeated again.
[0142]
The electrostatic latent image carrier (photosensitive drum) has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. The developing sleeve 6 of a non-magnetic cylinder that is a developer carrying member rotates so as to advance in the same direction as the surface of the electrostatic latent image carrying member in the developing unit. A multipolar permanent magnet 15 (magnet roll), which is a magnetic field generating means, is arranged in the non-magnetic cylindrical developing sleeve 6 so as not to rotate. The magnetic toner 13 in the developing device 1 is applied on a nonmagnetic cylindrical surface, and the magnetic toner particles are given a negative triboelectric charge by friction between the surface of the developing sleeve 6 and the magnetic toner particles. Further, by arranging an elastic doctor blade 8, the thickness of the toner layer is made thin (30 μm to 300 μm) and uniformly regulated so that the toner layer thinner than the gap between the photosensitive drum 3 and the developing sleeve 6 in the developing portion is not contacted. It forms so that it becomes. By adjusting the rotational speed of the sleeve 6, the sleeve surface speed is made substantially equal to or close to the speed of the electrostatic latent image carrier surface.
[0143]
An AC bias or a pulse bias may be applied to the developing sleeve 6 by the bias means 12. This AC bias preferably has f of 200 to 4,000 Hz and Vpp of 500 to 3,000 V.
[0144]
When the magnetic toner particles are transferred in the developing portion, the magnetic toner particles are transferred to the electrostatic latent image side by the electrostatic force on the surface of the photosensitive drum 3 holding the electrostatic latent image and the action of an AC bias or a pulse bias.
[0145]
Among the components such as the electrostatic latent image bearing member such as the photosensitive drum, the developing device, and the cleaning unit, a plurality of components are integrally coupled as a device unit to form a process cartridge. On the other hand, you may comprise so that attachment or detachment is possible. For example, a charging device and a developing device are integrally supported together with a photosensitive drum to form a process cartridge, which is a single unit that can be attached to and detached from the apparatus main body, and is configured to be removable using guide means such as a rail of the apparatus main body. Also good. At this time, the process cartridge may be configured with a cleaning means.
[0146]
FIG. 4 shows an embodiment of the process cartridge of the present invention. In this embodiment, a process cartridge 18 in which the developing device 1, the drum-shaped electrostatic latent image carrier (photosensitive drum) 3, the cleaner 14, and the primary charger 11 are integrated is illustrated.
[0147]
The process cartridge is replaced with a new cartridge when the magnetic toner 13 in the developing device 1 runs out.
[0148]
In this embodiment, the developing device 1 has the magnetic toner 13, and at the time of development, a predetermined electric field is formed between the photosensitive drum 3 and the developing sleeve 6, and the developing process is preferably performed. The distance between the photosensitive drum 3 and the developing sleeve 6 is very important. In this embodiment, for example, the center is 300 μm, and the error is adjusted to be ± 20 μm.
[0149]
In the process cartridge shown in FIG. 4, the developing device 1 includes a toner container 2 for storing the magnetic toner 13, and a developing area where the magnetic toner 13 in the toner container 2 faces the electrostatic latent image carrier 3 from the toner container 2. A developing sleeve 6 that is carried and transported to the surface, and an elastic blade for forming a toner thin layer on the developing sleeve by regulating the magnetic toner carried by the developing sleeve 6 and transported to the developing zone to a predetermined thickness 8.
[0150]
The developing sleeve 6 may have an arbitrary structure. Usually, it is comprised from the nonmagnetic developing sleeve 6 which incorporated the magnet 15. FIG. The developing sleeve 6 can also be a cylindrical rotating body as shown. It is also possible to form a belt that circulates and moves. Usually, aluminum or SUS is preferably used as the material.
[0151]
The elastic blade 8 is composed of a rubber elastic body such as urethane rubber, silicone rubber and NBR; a metal elastic body such as phosphor bronze and stainless steel plate; and an elastic plate formed of a resin elastic body such as polyethylene terephthalate and high density polyethylene. Is done. The elastic blade 8 is brought into contact with the developing sleeve 6 by the elasticity of the member itself, and is fixed to the toner container 2 by a blade support member 9 made of a rigid body such as iron. The elastic blade 8 is preferably in contact with the rotation direction of the developing sleeve 6 in the counter direction at a linear pressure of 5 to 80 g / cm.
[0152]
Instead of the elastic blade 8, it is also possible to use a magnetic doctor blade such as iron.
[0153]
As described above, the primary charging unit has been described using the charging roller 11 as the contact charging unit. However, the primary charging unit may be a contact charging unit such as a charging blade or a charging brush, or may be a non-contact corona charging unit. However, the contact charging means is preferable in that ozone generation due to charging is small. The transfer means has been described using the transfer roller 4 as described above, but may be a contact charging means such as a transfer blade, or a non-contact corona transfer means. However, the contact charging means is also preferable in that it generates less ozone due to transfer.
[0154]
When the image forming method of the present invention is applied to a facsimile printer, the optical image exposure L is an exposure for printing received data. FIG. 5 is a block diagram showing an example of this case.
[0155]
The controller 31 controls the image reading unit 30 and the printer 39. The entire controller 31 is controlled by the CPU 37. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 33. Data received from the partner station is sent to the printer 39 through the receiving circuit 32. Predetermined image data is stored in the image memory. The printer controller 38 controls the printer 39. 34 is a telephone.
[0156]
An image received from the line 35 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 32, and then the CPU 37 decodes the image information and sequentially stores it in the image memory 36. The When at least one page of image is stored in the memory 36, the image of that page is recorded. The CPU 37 reads one page of image information from the memory 36 and sends the combined one page of image information to the printer controller 38. When the printer controller 38 receives one page of image information from the CPU 37, the printer controller 38 controls the printer 39 to record the image information of the page.
[0157]
The CPU 37 receives the next page during recording by the printer 39.
[0158]
As described above, the image is received and recorded.
[0159]
【Example】
Although the basic configuration and features of the present invention have been described above, the present invention will be specifically described below based on examples. However, this does not limit the embodiment of the present invention. In addition, the number of parts in an Example is a weight part.
[0160]
(Example of fine particle production)
600 g of strontium carbonate and 320 g of titanium oxide were wet mixed in a ball mill for 8 hours and then filtered and dried. 5 kg / cm of this mixture²And calcined at a temperature of 1100 ° C. for 8 hours.
[0161]
The obtained strontium titanate is pulverized by a pulverizer using a jet stream, classified using an air classifier and aligned to some extent, then dispersed in water, and subjected to more precise classification using a centrifuge. By crushing after drying, strontium titanate fine particles I having a circle-equivalent mean diameter of 1.4 μm and ba of −0.51 in a number-based particle size distribution by a flow particle image analyzer were obtained.
[0162]
In the same manner, pulverization and classification were performed to prepare fine particles shown in Table 2.
[0163]

[0164]
After the above materials were premixed, they were melt kneaded with a twin-screw kneading extruder set at 130 ° C. The kneaded product is coarsely pulverized after cooling, finely pulverized by a pulverizer using a jet stream, and further classified twice using an elbow jet classifier to obtain toner particles (weight average particle size 5.91 μm, volume average particle size). 5.10 μm, 2.00 to 3.17 μm particles were 14.3% by number, and particles having a particle size of 1.00 μm or more and less than 2.00 μm were 3.1% by number).

To 100 parts of the toner particles obtained above, the above materials were mixed with a Henschel mixer to obtain an electrostatic charge image developing toner as shown in Example 1 in Table 3.
[0165]
<Example 2>
In the same manner as in Example 1, toner particles (weight average particle size 5.63 μm, volume average particle size 4.87 μm, particles of 2.00 to 3.17 μm are 26.5% by number, 1.00 μm or more and less than 2.00 μm. In the same manner except that 2.0 parts of titanium oxide I is used instead of strontium titanate, the electrostatic charge image development as shown in Example 2 of Table 3 was performed. A toner was obtained.
[0166]
<Example 3>
In the same manner as in Example 1, toner particles (weight average particle size 5.78 μm, volume average particle size 4.99 μm, 2.00 to 3.17 μm particles are 14.2% by number, 1.00 μm or more and less than 2.00 μm. In the same manner except that 0.5 part of zinc stearate I was used instead of strontium titanate, and electrostatic image development as shown in Example 3 of Table 3 was performed. Toner was obtained.
[0167]
<Example 4>
In the same manner as in Example 1, toner particles (weight average particle size 6.45 μm, volume average particle size 5.53 μm, 5.5% to 2.00 to 3.17 μm, 5.5% by number, 1.00 μm to less than 2.00 μm) In the same manner as in Example 4 in Table 3, except that 0.09 part of acrylic resin particles I are used instead of strontium titanate. Toner was obtained.
[0168]
<Example 5>
In the same manner as in Example 1, toner particles (weight average particle size 5.82 μm, volume average particle size 5.02 μm, 31.4% by number of particles of 2.00 to 3.17 μm, 1.00 μm or more and less than 2.00 μm) The toner for developing an electrostatic image as shown in Example 5 in Table 3 was obtained in the same manner except that 1.0 part of strontium titanate I was used.
[0169]
<Example 6>
In the same manner as in Example 1, toner particles (weight average particle size 5.10 μm, volume average particle size 4.44 μm, 2.00-3.17 μm particles are 20.1% by number, 1.00 μm to less than 2.00 μm) The toner for developing an electrostatic charge image as shown in Example 6 in Table 3 was obtained in the same manner except that 1.5 parts by weight of the strontium titanate I was used.
[0170]
<Example 7>
In the same manner as in Example 1, toner particles (weight average particle size 5.87 μm, volume average particle size 5.06 μm, 14.4% by number of particles of 2.00 to 3.17 μm, 1.00 μm to less than 2.00 μm) In the same manner except that 0.1 part of strontium titanate I was used, an electrostatic image developing toner as shown in Example 7 of Table 3 was obtained.
[0171]
<Example 8>
In the same manner as in Example 1, toner particles (weight average particle size 6.38 μm, volume average particle size 5.48 μm, 2.00 to 3.17 μm particles 12.8% by number, 1.00 μm or more and less than 2.00 μm) In the same manner except that 0.1 part of strontium titanate I was used, an electrostatic charge image developing toner as shown in Example 8 of Table 3 was obtained.
[0172]
<Example 9>
In the same manner as in Example 1, toner particles (weight average particle size 5.72 μm, volume average particle size 4.96 μm, 6.9 to 3.17 μm particles are 16.9% by number, 1.00 μm or more and less than 2.00 μm. In the same manner except that 1.0 part of strontium titanate II was used, an electrostatic charge image developing toner as shown in Example 9 of Table 3 was obtained.
[0173]
<Example 10>
In the same manner as in Example 1, toner particles (weight average particle size 5.90 μm, volume average particle size 5.08 μm, 2.00 to 3.17 μm of 15.0% by number, 1.00 μm or more and less than 2.00 μm) In the same manner except that 1.0 part of strontium titanate III was used, an electrostatic charge image developing toner as shown in Example 10 of Table 3 was obtained.
[0174]
<Example 11>
Toner particles (weight average particle size 5.86 μm, volume average particle size 5.03 μm, 2.00-3.17 μm particles were obtained in the same manner as in Example 1 except that classification was performed only once by elbow jet. 22.7% by number, particles having a particle size of 1.00 μm or more and less than 2.00 μm are 12.0% by number), and using 0.8 parts of strontium titanate I is also similar to Example 11 in Table 3. An electrostatic charge image developing toner as shown was obtained.
[0175]
<Example 12>
Toner particles (weight average particle size 6.15 μm, volume average particle size 5.28 μm, particles of 2.00 to 3.17 μm are 10.7% by number, 1.00 μm or more by changing the classification conditions in Example 1 The number of particles less than 2.00 μm was 5.1% by number), and external addition was performed in the same manner as in Example 1 to obtain an electrostatic charge image developing toner as shown in Example 12 of Table 3.
[0176]
Table 5 and Table 6 show the particle size distribution of the number of equivalent circle diameters of the toner after external addition and the toner particles of the external additive measured by the flow type particle image analyzer, respectively. It shows in FIG.1 and FIG.2, respectively.
[0177]
<Comparative Example 1>
In the same manner as in Example 1, toner particles (weight average particle diameter 7.52 μm, volume average particle diameter 6.40 μm, 2.00 to 3.17 μm of 7.9% by number, 1.00 μm or more and less than 2.00 μm) In the same manner except that 1.0 part of comparative titanium oxide is used instead of strontium titanate. Toner was obtained.
[0178]
<Comparative example 2>
In the same manner as in Example 1, toner particles (weight average particle size 11.32 μm, volume average particle size 9.49 μm, 2.00 to 3.17 μm, 0.2% by number, 1.00 μm or more and less than 2.00 μm) In the same manner except that strontium titanate I was not used, an electrostatic charge image developing toner as shown in Comparative Example 2 in Table 3 was obtained.
[0179]
<Comparative Example 3>
In the same manner as in Example 1, toner particles (weight average particle size 5.71 μm, volume average particle size 4.93 μm, 5.4 to 3.17 μm particles are 15.4% by number, 1.00 μm or more and less than 2.00 μm. In the same manner, except that 1.0 part of comparative dry silica was used in place of strontium titanate I, an electrostatic charge image as shown in Comparative Example 3 of Table 3 was obtained. A developing toner was obtained.
[0180]
<Comparative example 4>
In the same manner as in Example 1, toner particles (weight average particle diameter 5.85 μm, volume average particle diameter 5.02 μm, 15.1 to 3.17 μm particles are 15.1% by number, 1.00 μm to less than 2.00 μm) In the same manner except that 1.0 part of strontium titanate for comparison was used, a toner for developing an electrostatic charge image as shown in Comparative Example 4 of Table 3 was obtained. .
[0181]
Next, these prepared toners were evaluated by the following methods. As the image forming apparatus shown in FIG. 3, a commercially available laser beam printer LBP-450 (manufactured by Canon) was used, and the printing speed was changed from 12 sheets (A4) / 1 minute to 20 sheets (A4) / 1 minute. A printout test of 30,000 sheets (30K) was performed under each environment (10 ° C./15% RH) and high temperature and high humidity (32.5 ° C./90% RH). When the toner runs out, a printout test is continued by providing a cut in the toner container portion at the top of the cartridge and replenishing the toner from there. The obtained images were evaluated for the following items.
[0182]
(1) Dot reproducibility
An independent 1-dot pattern was printed out in the images of the initial durability in a high-temperature and high-humidity environment and after 30K durability, and the reproducibility of the 1-dot was evaluated by microscopic observation.
A: Very good (dots are faithfully reproduced and there is almost no toner scattering)
B: Good (dots are faithfully reproduced)
C: Normal (slightly dirty image)
D: Poor (the image is distorted and reproducibility is poor)
[0183]
(2) Image density
Normal high-temperature, high-humidity environment images with an initial durability and after 30K durability, and low-temperature, low-humidity environments with 30K durability after normal plain paper for copying machines (75g / m²) And the image density at the time of printout. For the image density, a “Macbeth reflection densitometer” (manufactured by Macbeth) was used to measure a relative density with respect to a printout image of a white background portion having a document density of 0.00.
[0184]
(3) fog
Fog is calculated by comparing the whiteness of the transfer paper measured with a reflectometer (manufactured by Tokyo Denshoku Co., Ltd.) and the whiteness of a solid white image after 30,000 prints (30K) in a low-temperature and low-humidity environment. did.
[0185]
Table 4 shows the evaluation results of (1) to (3) above.
[0186]
[Table 2]

[0187]
[Table 3]

[0188]
[Table 4]

[0189]
[Table 5]

[0190]
[Table 6]

[0191]
【The invention's effect】
According to the present invention, an image with excellent dot reproducibility can be obtained without lowering the charge amount of the toner even when the durability is maintained for a long time in a high-temperature and high-humidity environment, without causing a decrease in image density and image quality. be able to.
[Brief description of the drawings]
FIG. 1 is a particle size distribution diagram based on the number of equivalent circle diameters of particles measured by a flow particle image analyzer of toner prepared in Example 12 of the present invention.
2 is a particle size distribution diagram based on the number of equivalent circle diameters of toner particles measured by a flow particle image analyzer of toner particles before external addition of external additive fine particles in Example 12 of the present invention. FIG.
FIG. 3 is a schematic explanatory diagram of an image forming apparatus used in an embodiment of the present invention.
FIG. 4 is an explanatory diagram showing an example of a process cartridge according to the present invention.
FIG. 5 is a block diagram when the image forming method of the present invention is applied to a facsimile printer.
[Explanation of symbols]
1 Developer
2 Developer container
3 Photoconductor
4 Transfer means
5 Laser light or analog light
6 Toner carrier
7 Cleaning blade
8 Regulatory blade
11 Charging means
12 Bias application means
13 Developer
14 Cleaning means
15 Magnetic field generating means

Claims (87)

In toner for electrostatic image development having toner particles containing at least a binder resin and a colorant, and external additive fine particles,
The toner is
(I) The value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, and the weight average particle diameter (D ₄ ) of the toner. X μm and the Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm are the following conditions (1) and (2):
−5X + 35 ≦ Y ≦ −25X + 180 (1)
3.5 ≦ X ≦ 6.5 (2)
And (ii) the number-based particle size distribution of particles with an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by a flow particle image analyzer, the equivalent circle diameter is 1.00 μm or more and 1. The A number% of the content of particles less than 03 μm and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (3):
B−A ≦ 0.30 (3)
A toner for developing electrostatic images, wherein the toner has a particle size distribution satisfying The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The A number% of the content and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (4):
−0.63 ≦ B−A ≦ 0.30 (4)
The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a particle size distribution satisfying In a value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, X μm of the weight average particle diameter (D ₄ ) of the toner, Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm is the following conditions (5) and (6):
−5X + 35 ≦ Y ≦ −12.5X + 98.75 (5)
4.0 ≦ X ≦ 6.3 (6)
The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a particle size distribution satisfying The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 4. The toner for developing an electrostatic charge image according to claim 1, wherein the C number% of the content is 10 number% or more. The external additive particles have a circle-equivalent mean diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 5. The electrostatic image developing toner according to claim 1, wherein the toner has an external additive fine particle A. 6. The external additive particles have a circle-equivalent mean diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. 5. The electrostatic image developing toner according to claim 1, wherein the toner has an external additive fine particle A. 6. The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive fine particles have a circle-equivalent mean diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The toner for developing an electrostatic charge image according to claim 1, wherein the toner has an external additive fine particle A. The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive particles have a circle-equivalent average diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The toner for developing an electrostatic charge image according to claim 1, wherein the toner has an external additive fine particle A. The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The number a of particles of less than 1% and the number of b having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm satisfy the following condition (7):
b−a ≦ 0.30 (7)
The toner for developing an electrostatic charge image according to any one of claims 5 to 8, wherein the toner has a particle size distribution satisfying: The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The particle size distribution satisfying the following condition (8): a number% of particles of less than and b number% of equivalent circle diameter of 2.00 μm or more and less than 2.06 μm:
−0.63 ≦ b−a ≦ 0.30 (8)
The toner for developing an electrostatic image according to claim 5, wherein the toner for developing an electrostatic image is provided. Before preparing the toner by mixing the toner particles and the external additive fine particles, the toner particles are particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 2. The particle size distribution based on the number of particles, wherein the content of particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm is previously reduced so as to be less than 10% by number. The toner for developing an electrostatic charge image according to any one of 10. The external additive fine particles have external additive fine particles A,
Before the toner particles and the external additive fine particles are mixed to prepare the toner, the external additive fine particles A are subjected to flow type particle image analysis by performing classification by a wet classification method using precipitation separation. In the particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by the apparatus, the number a of particles having an equivalent circle diameter of 1.00 μm or more and less than 1.03 μm and the equivalent circle diameter of 2 are used. B number% of not less than 0.000 μm and less than 2.06 μm satisfies the following condition (7):
b−a ≦ 0.30 (7)
12. The toner for developing an electrostatic charge image according to claim 1, wherein the particle size distribution is adjusted so as to have a particle size distribution satisfying the above. The external additive fine particles A include metal oxide particles, composite metal oxide particles, metal salt particles, clay mineral particles, phosphate compound particles, silicon compound particles, carbon compound particles, resin particles, organic compounds and inorganic compounds. 13. The electrostatic image developing toner according to claim 1, comprising at least one particle selected from the group consisting of composite particles, fatty acid derivative particles and lubricant particles. The external additive fine particles A include at least one kind of particles selected from the group consisting of zinc oxide, aluminum oxide, titanium oxide, zirconium oxide, manganese oxide, strontium titanate, magnesium titanate and barium titanate. The toner for developing an electrostatic charge image according to any one of claims 1 to 12. 2. The toner according to claim 1, wherein the toner has a porosity of 0.45 to 0.70 when tapping the toner obtained by the following formula: porosity = (true density−tap density) / true density. The toner for developing an electrostatic charge image according to any one of 14. 2. The toner according to claim 1, wherein the toner has a porosity of 0.50 to 0.70 when tapping toner obtained by the following formula: porosity = (true density−tap density) / true density. The toner for developing an electrostatic charge image according to any one of 14. 6. The electrostatic image developing toner according to claim 5, wherein the toner has the external additive fine particles A and the inorganic fine powder B as the external additive fine particles. 18. The electrostatic image developing toner according to claim 17, wherein the inorganic fine powder B contains a hydrophobic silica fine powder. 6. The electrostatic charge image according to claim 5, wherein the toner includes the external additive fine particles A and fine particle aggregates C composed of silicone oil or silicone varnish and fine particles as the external additive fine particles. Development toner. 20. The electrostatic charge image developing toner according to claim 19, wherein the fine particle aggregate C is treated with 20 to 90% by weight of the silicone oil or the silicone varnish. 6. The electrostatic image developing toner according to claim 5, wherein the toner has the external additive fine particles A and the resin fine particles D as the external additive fine particles. The toner for developing an electrostatic charge image according to claim 21, wherein the resin fine particles D contain a styrene-based copolymer. The toner has the external additive fine particles A, inorganic fine powder B, fine particle aggregate C composed of silicone oil or silicone varnish and fine particles, and resin fine particles D as the external additive fine particles. The toner for developing an electrostatic charge image according to claim 5. 24. The toner particles according to claim 1, wherein the toner particles contain a negative charge control agent and a magnetic material as the colorant, and the toner is a negatively chargeable magnetic toner. Toner for developing electrostatic images. 25. The electrostatic image developing toner according to claim 1, wherein the toner is a magnetic toner having magnetic toner particles containing a magnetic material as a colorant. 26. The electrostatic image developing toner according to claim 25, wherein the magnetic toner particles contain 30 to 200 parts by weight of the magnetic material with respect to 100 parts by weight of the binder resin. A charging step of charging the electrostatic latent image carrier for carrying the electrostatic latent image;
An electrostatic latent image forming step of forming an electrostatic latent image on a charged electrostatic latent image carrier; and a developing step of developing the electrostatic latent image of the electrostatic latent image carrier with toner to form a toner image. ;
In an image forming method having
The toner has toner particles containing at least a binder resin and a colorant, and external additive fine particles,
The toner is
(I) The value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, and the weight average particle diameter (D ₄ ) of the toner. X μm and the Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm are the following conditions (1) and (2):
−5X + 35 ≦ Y ≦ −25X + 180 (1)
3.5 ≦ X ≦ 6.5 (2)
And (ii) the number-based particle size distribution of particles with an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by a flow particle image analyzer, the equivalent circle diameter is 1.00 μm or more and 1. The A number% of the content of particles less than 03 μm and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (3):
B−A ≦ 0.30 (3)
An image forming method characterized by having a particle size distribution satisfying The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The A number% of the content and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (4):
−0.63 ≦ B−A ≦ 0.30 (4)
28. The image forming method according to claim 27, wherein the image forming method has a particle size distribution satisfying: In a value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, X μm of the weight average particle diameter (D ₄ ) of the toner, Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm is the following conditions (5) and (6):
−5X + 35 ≦ Y ≦ −12.5X + 98.75 (5)
4.0 ≦ X ≦ 6.3 (6)
The image forming method according to claim 27 or 28, wherein the image forming method has a particle size distribution satisfying the following conditions. The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 30. The image forming method according to claim 27, wherein the C number% of the content is 10 number% or more. The external additive particles have a circle-equivalent mean diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 31. The image forming method according to claim 27, wherein the external additive fine particles A are included. The external additive particles have a circle-equivalent mean diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. 31. The image forming method according to claim 27, wherein the external additive fine particles A are included. The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive fine particles have a circle-equivalent mean diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. 33. The image forming method according to claim 27, wherein the external additive fine particles A are included. The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive particles have a circle-equivalent average diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. 33. The image forming method according to claim 27, wherein the external additive fine particles A are included. The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The number a of particles of less than 1% and the number of b having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm satisfy the following condition (7):
b−a ≦ 0.30 (7)
35. The image forming method according to claim 31, wherein the image forming method has a particle size distribution satisfying the following conditions. The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The particle size distribution satisfying the following condition (8): a number% of particles of less than and b number% of equivalent circle diameter of 2.00 μm or more and less than 2.06 μm:
−0.63 ≦ b−a ≦ 0.30 (8)
35. The image forming method according to claim 31, further comprising: Before preparing the toner by mixing the toner particles and the external additive fine particles, the toner particles are particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 28. The particle size distribution on the basis of the number of particles, wherein the content of particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm is previously reduced so as to be less than 10% by number. 36. The image forming method according to any one of 36. The external additive fine particles have external additive fine particles A,
Before the toner particles and the external additive fine particles are mixed to prepare the toner, the external additive fine particles A are subjected to flow type particle image analysis by performing classification by a wet classification method using precipitation separation. In the particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by the apparatus, the number a of particles having an equivalent circle diameter of 1.00 μm or more and less than 1.03 μm and the equivalent circle diameter of 2 are used. B number% of not less than 0.000 μm and less than 2.06 μm satisfies the following condition (7):
b−a ≦ 0.30 (7)
37. The image forming method according to claim 27, wherein the particle size distribution is adjusted so as to have a particle size distribution satisfying the above. The external additive fine particles A include metal oxide particles, composite metal oxide particles, metal salt particles, clay mineral particles, phosphate compound particles, silicon compound particles, carbon compound particles, resin particles, organic compounds and inorganic compounds. The image forming method according to any one of claims 27 to 38, comprising at least one particle selected from the group consisting of composite particles, fatty acid derivative particles and lubricant particles. The external additive fine particles A include at least one kind of particles selected from the group consisting of zinc oxide, aluminum oxide, titanium oxide, zirconium oxide, manganese oxide, strontium titanate, magnesium titanate, and barium titanate. The image forming method according to any one of claims 27 to 38, wherein 28. The toner according to claim 27, wherein the toner has a porosity of 0.45 to 0.70 when tapping toner obtained by the following formula: porosity = (true density−tap density) / true density. 40. The image forming method according to any one of 40. 28. The toner according to claim 27, wherein the toner has a porosity of 0.50 to 0.70 when tapping toner obtained by the following formula: porosity = (true density−tap density) / true density. 40. The image forming method according to any one of 40. 32. The image forming method according to claim 31, wherein the toner has the external additive fine particles A and the inorganic fine powder B as the external additive fine particles. 44. The image forming method according to claim 43, wherein the inorganic fine powder B includes a hydrophobic silica fine powder. 32. The image forming method according to claim 31, wherein the toner has the external additive fine particles A and fine particle aggregate C composed of silicone oil or silicone varnish and fine particles as the external additive fine particles. . 46. The image forming method according to claim 45, wherein the fine particle aggregate C is treated with 20 to 90% by weight of the silicone oil or the silicone varnish. 32. The image forming method according to claim 31, wherein the toner has the external additive fine particles A and the resin fine particles D as the external additive fine particles. 48. The image forming method according to claim 47, wherein the resin fine particles D have a styrene copolymer. The toner has the external additive fine particles A, inorganic fine powder B, fine particle aggregate C composed of silicone oil or silicone varnish and fine particles, and resin fine particles D as the external additive fine particles. The image forming method according to claim 31. 50. The toner particles according to claim 27, wherein the toner particles contain a negative charge control agent and a magnetic material as the colorant, and the toner is a negatively chargeable magnetic toner. Image forming method. 51. The image forming method according to claim 27, wherein the toner is a magnetic toner having magnetic toner particles containing a magnetic material as a colorant. 52. The image forming method according to claim 51, wherein the magnetic toner particles contain 30 to 200 parts by weight of the magnetic material with respect to 100 parts by weight of the binder resin. In the developing section in the developing step, the layer thickness of the toner layer carried on the toner carrier is smaller than the interval between the electrostatic latent image carrier and the toner carrier for carrying the toner, 53. The toner layer carried on the toner carrying member develops an electrostatic latent image formed on the electrostatic latent image carrying member in a non-contact state. The image forming method described. 54. The electrostatic latent image formed on the electrostatic latent image carrier is developed by applying a bias voltage to the toner carrier in the developing step. The image forming method described. 55. The image forming method according to claim 27, wherein the latent electrostatic image bearing member is an electrophotographic photosensitive member. In a process cartridge that is detachably attached to the image forming apparatus main body,
The process cartridge includes: (i) an electrostatic latent image carrier for carrying an electrostatic latent image; and (ii) a toner image by developing the electrostatic latent image carried on the electrostatic latent image carrier. A developing means holding toner for forming
The toner has toner particles containing at least a binder resin and a colorant, and external additive fine particles,
The toner is
(I) The value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, and the weight average particle diameter (D ₄ ) of the toner. X μm and the Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm are the following conditions (1) and (2):
−5X + 35 ≦ Y ≦ −25X + 180 (1)
3.5 ≦ X ≦ 6.5 (2)
And (ii) the number-based particle size distribution of particles with an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by a flow particle image analyzer, the equivalent circle diameter is 1.00 μm or more and 1. The A number% of the content of particles less than 03 μm and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (3):
B−A ≦ 0.30 (3)
A process cartridge having a particle size distribution satisfying The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The A number% of the content and the B number% of the content of particles having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm are the following condition (4):
−0.63 ≦ B−A ≦ 0.30 (4)
57. The process cartridge according to claim 56, wherein the process cartridge has a particle size distribution satisfying the following conditions. In a value calculated based on the volume-based and number-based particle size distribution of particles having a particle diameter of 2.00 μm to 40.30 μm measured by a Coulter counter, X μm of the weight average particle diameter (D ₄ ) of the toner, Y number% of the content of particles having a particle diameter of 2.00 to 3.17 μm is the following conditions (5) and (6):
−5X + 35 ≦ Y ≦ −12.5X + 98.75 (5)
4.0 ≦ X ≦ 6.3 (6)
58. The process cartridge according to claim 56, wherein the process cartridge has a particle size distribution satisfying the following conditions. The toner has a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 59. A process cartridge according to claim 56, wherein the C number% of the content is 10% by number or more. The external additive particles have a circle-equivalent mean diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. 60. The process cartridge according to any one of claims 56 to 59, further comprising: The external additive particles have a circle-equivalent mean diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. 60. The process cartridge according to any one of claims 56 to 59, further comprising: The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive fine particles have a circle-equivalent average diameter of 0.60 to 4.00 μm in a particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The process cartridge according to any one of claims 56 to 61, further comprising: The toner particles are particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm in the number-based particle size distribution of the equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. Is less than 10% by number,
The external additive particles have a circle-equivalent average diameter of 1.00 to 3.00 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The process cartridge according to any one of claims 56 to 61, further comprising: an external additive fine particle A. The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The number a of particles of less than 1% and the number of b having an equivalent circle diameter of 2.00 μm or more and less than 2.06 μm satisfy the following condition (7):
b−a ≦ 0.30 (7)
64. The process cartridge according to claim 60, wherein the process cartridge has a particle size distribution satisfying the following conditions. The external additive fine particles A have a circle-equivalent diameter of 1.00 μm or more and 1.03 μm in the number-based particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow particle image analyzer. The particle size distribution satisfying the following condition (8): a number% of particles of less than and b number% of equivalent circle diameter of 2.00 μm or more and less than 2.06 μm:
−0.63 ≦ b−a ≦ 0.30 (8)
64. A process cartridge according to any one of claims 60 to 63, wherein: Before preparing the toner by mixing the toner particles and the external additive fine particles, the toner particles are particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm as measured by a flow type particle image analyzer. In the number-based particle size distribution, the content of particles having an equivalent circle diameter of 1.00 μm or more and less than 2.00 μm is previously reduced so as to be less than 10% by number. 65. The process cartridge according to any one of 65. The external additive fine particles have external additive fine particles A,
Before the toner particles and the external additive fine particles are mixed to prepare the toner, the external additive fine particles A are subjected to flow type particle image analysis by performing classification by a wet classification method using precipitation separation. In the particle size distribution based on the number of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm measured by the apparatus, the number a of particles having an equivalent circle diameter of 1.00 μm or more and less than 1.03 μm and the equivalent circle diameter of 2 are used. B number% of not less than 0.000 μm and less than 2.06 μm satisfies the following condition (7):
b−a ≦ 0.30 (7)
67. The process cartridge according to claim 56, wherein the particle size distribution is adjusted so as to have a particle size distribution satisfying the following conditions. The external additive fine particles A include metal oxide particles, composite metal oxide particles, metal salt particles, clay mineral particles, phosphate compound particles, silicon compound particles, carbon compound particles, resin particles, organic compounds and inorganic compounds. 68. The process cartridge according to claim 56, comprising at least one particle selected from the group consisting of composite particles, fatty acid derivative particles and lubricant particles. The external additive fine particles A include at least one kind of particles selected from the group consisting of zinc oxide, aluminum oxide, titanium oxide, zirconium oxide, manganese oxide, strontium titanate, magnesium titanate and barium titanate. 68. A process cartridge according to any one of claims 56 to 67, wherein: 57. The toner according to claim 56, wherein the toner has a porosity of 0.45 to 0.70 when tapping toner obtained by the following formula: porosity = (true density−tap density) / true density. 69. The process cartridge according to any one of 69. 57. The toner according to claim 56, wherein the toner has a porosity of 0.50 to 0.70 at the time of tapping the toner obtained by the following formula: porosity = (true density−tap density) / true density. 69. The process cartridge according to any one of 69. 61. The process cartridge according to claim 60, wherein the toner has the external additive fine particles A and the inorganic fine powder B as the external additive fine particles. The process cartridge according to claim 72, wherein the inorganic fine powder B has a hydrophobic silica fine powder. 61. The process cartridge according to claim 60, wherein the toner has the external additive fine particles A and fine particle aggregate C composed of silicone oil or silicone varnish and fine particles as the external additive fine particles. 75. The process cartridge according to claim 74, wherein the fine particle aggregate C is treated with 20 to 90% by weight of the silicone oil or the silicone varnish. 61. The process cartridge according to claim 60, wherein the toner has the external additive fine particles A and the resin fine particles D as the external additive fine particles. 77. The process cartridge according to claim 76, wherein the resin fine particles D have a styrene copolymer. The toner has the external additive fine particles A, inorganic fine powder B, fine particle aggregate C composed of silicone oil or silicone varnish and fine particles, and resin fine particles D as the external additive fine particles. The process cartridge according to claim 60. 79. The toner particle according to claim 56, wherein the toner particles contain a negative charge control agent and a magnetic material as the colorant, and the toner is a negatively chargeable magnetic toner. Process cartridge. 80. The process cartridge according to claim 56, wherein the toner is a magnetic toner having magnetic toner particles containing a magnetic material as a colorant. 81. The process cartridge according to claim 80, wherein the magnetic toner particles contain 30 to 200 parts by weight of the magnetic material with respect to 100 parts by weight of the binder resin. The electrostatic latent image carrier and the toner carrier for carrying the toner are arranged at a distance from each other, and the layer thickness of the toner layer carried on the toner carrier in the developing unit is arranged. The toner layer that is thinner than the interval and that is carried on the toner carrying member develops the electrostatic latent image formed on the electrostatic latent image carrying member in a non-contact state. Item 82. The process cartridge according to any one of Items 56 to 81. 83. The process cartridge according to claim 56, wherein a bias voltage is applied to the toner carrier when developing the electrostatic latent image formed on the electrostatic latent image carrier. . 84. The process cartridge according to claim 56, wherein the electrostatic latent image carrier is an electrophotographic photoreceptor. 85. The apparatus according to claim 56, further comprising a charging member for primary charging of the electrostatic latent image carrier in addition to the electrostatic latent image carrier and the developing means. The described process cartridge. 86. In addition to the latent electrostatic image bearing member and the developing means, a cleaning member for cleaning the surface of the latent electrostatic image bearing member is further provided. The described process cartridge. In addition to the electrostatic latent image carrier and the developing means, the apparatus further comprises a charging member for primarily charging the electrostatic latent image carrier and a cleaning member for cleaning the surface of the electrostatic latent image carrier. The process cartridge according to any one of claims 56 to 86, wherein the process cartridge is provided.

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