JP3780159B2 - Dry toner, manufacturing method thereof and image forming method - Google Patents

Description

【００９３】
［式中、Ｘ₁およびＸ₂は水素原子、低級アルキル基、低級アルコキシ基、ニトロ基またはハロゲン原子を表し、Ｘ₁とＸ₂は同じであっても異なっていてもよく、mおよびm’は１〜３の整数を表し、Ｒ₁およびＲ₃は水素原子、炭素数１〜１８のアルキル基、炭素数１〜１８のアルケニル基、スルホンアミド基、メシル基、スルホニル基、ヒドロキシル基、炭素数１〜１８のアルコキシ基、アセチルアミノ基、ベンゾイルアミノ基、ハロゲン原子又は−ＣＯＯＲ₅を表し、Ｒ₁とＲ₃は同じであっても異なっていてもよく、ｎおよびｎ’は１〜３の整数を表し、Ｒ₂およびＲ₄は、水素原子またはニトロ基を表し、Ｒ₅はアルキル基又はアリール基を表し、Ａ⁺は水素イオン、ナトリウムイオン、カリウムイオン又はアンモニウムイオンを表す。］
【００９４】
Ｘ₁およびＸ₂の低級アルキル基としては、メチル基、エチル基、プロピル基の如き炭素数１〜１０のアルキル基が挙げられる。Ｘ１およびＸ２の低級アルコキシ基としては、メトキシ基、エトキシ基、プロピオキシ基の如き炭素数１〜１０のアルコキシ基が挙げられる。
【００９５】
Ｘ₁、Ｘ₂、Ｒ₁およびＲ₃のハロゲン原子としては、フッ素、臭素、塩素、ヨウ素が挙げられる。
【００９６】
Ｘ₁およびＸ₂の好ましい基としては、水素原子又はニトロ基が挙げられる。
【００９７】
Ｒ₁およびＲ₃の炭素数１〜１８のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基が挙げられる。
【００９８】
Ｒ₁およびＲ₃の炭素数１〜１８のアルケニル基としては、ビニル基、アリル基、プロペニル基、ブテニル基が挙げられる。
【００９９】
Ｒ₁およびＲ₃の炭素数１〜１８のアルコキシ基としては、メトキシ基、エトキシ基、プロピオキシ基、ブトキシ基が挙げられる。
【０１００】
またＲ₁およびＲ₃は−ＣＯＯＲ₅で表される基でも良く、この場合のＲ₅は、メチル基、エチル基、プロピル基、フェニル基、ナフチル基が挙げられる。
【０１０１】
これらの中で、好ましいＲ₁およびＲ₃としては、塩素が挙げられる。
【０１０２】
好ましいＲ₂およびＲ₄としては、水素が挙げられる。
【０１０３】
上記荷電制御剤の好ましい具体例としては、下記一般式（II）及び（III）に示す化合物が挙げられる。
【０１０４】
【外３】

【０１０５】
【外４】

【０１０６】
上記荷電制御剤は、結着樹脂１００質量部に対し０．１〜１０質量部使用することが好ましく、さらに好ましくは、０．１〜５質量部である。
【０１０７】
また、本発明のトナーにおいては、帯電安定性、現像性、流動性、耐久性向上のため、トナー粒子に外添剤が混合される。
【０１０８】
本発明に用いられる外添剤としては、まず無機微粉体が挙げられる。具体的には、シリカ微粉体、酸化チタン、アルミナ微粉体が挙げられ、特にシリカ微粉体が好ましく用いられる。この中でもＢＥＴ法で測定した窒素吸着による比表面積が３０ｍ²／ｇ以上、特に５０〜４００ｍ²／ｇの範囲のものが良好な結果を与える。トナー粒子１００質量部に対して無機微粉体０．０１〜８質量部、好ましくは０．１〜５質量部使用するのが良い。無機微粉体の比表面積は、トナーの比表面積と同様にＢＥＴ法に後述の方法によって算出することができる。
【０１０９】
本発明に用いられる無機微粉体は、疎水化、帯電性コントロールの目的でシリコーンワニス、各種変性シリコーンワニス、シリコーンオイル、各種変性シリコーンオイル、シランカップリング剤、官能基を有するシランカップリング剤、その他の有機ケイ素化合物の如き処理剤で処理されていることが好ましい。特に、シリコーンオイル及び／又はシランカップリング剤で処理された疎水化シリカが好ましい。
【０１１０】
本発明のトナーに含有される他の外添剤としては、テフロン、ステアリン酸亜鉛、ポリフッ化ビニリデンの如き滑剤(中でもポリフッ化ビニリデンが好ましい)；酸化セリウム、炭化ケイ素、チタン酸ストロンチウムの如き研磨剤（中でもチタン酸ストロンチウムが好ましい）；ケーキング防止剤；カーボンブラック、酸化亜鉛、酸化アンチモン、酸化スズの如き導電性付与剤；トナー粒子と逆極性の白色微粒子及び黒色微粒子の如き現像性向上剤が挙げられる。
【０１１１】
本発明において、無機微粉体や他の外添剤をトナー粒子に添加し、攪拌・混合して製造されたトナーの場合には、トナー粒子の有する後述する各種物性値の測定は、これらの無機微粒子や他の外添剤を除去した後のトナー粒子を用いて行うことができる。これらの無機微粒子や他の外添剤をトナー粒子表面から除去する方法は特に制限されないが、例えば以下のようにしてトナーを水洗することにより行うことができる。
【０１１２】
まずドデシルベンゼンスルホン酸ナトリウムの如き界面活性剤を添加した水の中に、トナーを加えて充分に攪拌、混合する。この操作で、比較的粒径の大きな無機微粒子や他の外添剤がトナー粒子から遊離し、水中にトナー粒子と無機微粒子や他の外添剤が別々に分散される。次いでこの混合分散液からトナー粒子を単離する。単離方法としては、例えば、適度な目開きを持つ瀘紙を用いて濾過操作を行うことにより、瀘紙上にトナー粒子、濾液に無機微粒子や他の外添剤を含む水溶液として分離することができる。また、他の単離方法として、混合分散液を湿式分級することにより、トナー粒子を単離する方法も採用することができる。
【０１１３】
本発明のトナーは、示差走査熱量計により測定されるＤＳＣ曲線において、主たるガラス転移温度（Ｔｇ）が、４０〜７０℃に観測されるものである。本発明において、ガラス転移温度の異なる複数の樹脂を使用する場合には、ＤＳＣにおいて複数のガラス転移温度が観測される場合がある。その場合には、吸熱量の大きな方を主たるガラス転移温度と定義する。
【０１１４】
主たるガラス転移温度が４０℃未満だと、トナーの耐ブロッキング性が低下することにより現像器内での流動性が低下したり、トナー担持体や静電潜像担持体上で極めて融着しやすくなるため好ましくない。７０℃を越えると、一定の熱量を与えられたトナーの溶融粘度が高くなり、その結果として定着温度が高くなる。即ち、必要とする熱量が増大したり、同じ熱量で定着させるためには、例えば、転写材に与える圧力を高めなければならず、好ましいものではない。本発明のトナーのより好ましいガラス転移温度は、４２〜６８℃であり、特に４５〜６５℃である。
【０１１５】
本発明におけるトナーのＤＳＣ曲線は、測定原理から高精度の内熱式入力補償型の示差走査熱量計で測定することができる。例えば、パーキンエルマー社製のＤＳＣ−７が利用できる。測定方法は、「ASTM D3418-8」に準じて行うことができる。装置検出部の温度補正はインジウムと亜鉛の融点を用い、熱量の補正についてはインジウムの融解熱を用いる。測定サンプルにはアルミニウム製のパンを用い、対照用に空パンをセットし、昇温速度１０℃／分で測定を行うことができる。
【０１１６】
ガラス転移温度（Ｔｇ）の測定は、具体的には以下の方法により測定できる。
【０１１７】
サンプルを一旦昇温してから冷却した後、二度目の昇温時のＤＳＣカーブより吸熱ピーク前の基線と吸熱ピーク後の基線の中線と、立ち上がり曲線での交点をもってガラス転移温度（Ｔｇ）とする（図８参照）。
【０１１８】
トナーが、示差走査熱量計により測定されるＤＳＣ曲線においてガラス転移温度（Ｔｇ）が４０〜７０℃に観測されるようにするには、具体的には、重合性単量体の種類や比率を変えて調整すればよい。
【０１１９】
本発明におけるトナーは、雰囲気温度２３℃、相対湿度６５％の環境に７２時間放置したときのＢＥＴ法による比表面積をＡ（ｍ²／ｇ）、上記トナーを雰囲気温度５０℃、相対湿度３％の環境に７２時間放置したときのＢＥＴ法による比表面積をＢ（ｍ²／ｇ）とするときに、０．８≦Ａ≦４．０、かつ０．８０≦（Ｂ／Ａ）≦１．０５の関係式を満足するものである。Ａが０．８未満だと、トナーの流動性のコントロールが難しくなったり、高解像度な画像を得にくくなる傾向が強くなったりすることがあり、４．０を越えると、トナーの帯電性にバラツキが多くなったり、トナー担持体や静電潜像担持体とのマッチングに劣るようになったりすることで、高品質な画像が得られにくくなることがある。さらに、１．０≦Ａ≦３．０の範囲がより好ましい。また（Ｂ／Ａ）の値としては、０．８５≦（Ｂ／Ａ）≦１．０５、の範囲が好ましく、更には、０．９０≦（Ｂ／Ａ）≦１．０５の範囲が好ましく、特には０．９２≦（Ｂ／Ａ）≦１．０３、最も好ましくは０．９２≦（Ｂ／Ａ）≦１．００である。
【０１２０】
（Ｂ／Ａ）が減少するということは、トナー表面に存在するシリカなどの外添剤が、雰囲気温度５０℃、相対湿度３％の環境に７２時間放置することにより埋没することを示し、この値が０．８０未満だと、高品質な画像を安定して得ることができない傾向がある。（Ｂ／Ａ）が、１．０５を越えるということは、トナー粒子自身の変形が大きいということであり、やはり高品質な画像を安定して得ることができないことがある。
【０１２１】
本発明におけるＢＥＴ法による比表面積とは、例えば、比表面積測定装置オートソーブ１（湯浅アイオニクス社製）を用いて試料表面に窒素ガスを吸着させ、ＢＥＴ多点法を用いて比表面積を算出したものである。
【０１２２】
ＢＥＴ比表面積に係る上記の規定を満たすトナーを製造する方法は、特に制限されないが、例えば、粉砕法或いは重合法によってジエン単量体を含有する樹脂粒子を製造し、その表面近傍に存在するジエン単量体の有する未反応の二重結合を反応させることにより、達成することができる。
【０１２３】
こうして得られたトナー粒子は、粒子表面のフレキシビリティーが大きく損なわれることなく３次元構造をとることにより強度が増す。そのため、高温高湿環境下にトナーを放置した場合においても、外添剤のトナー粒子への埋没が生じにくくなり、またトナー粒子自体の変形も抑制される。また、トナーの表面にジエン単量体による網目構造が形成されるため、空気中にある水分の影響を受けにくくなり、更なる帯電の安定化が図られる。
【０１２４】
尚、本願発明のトナーの製造方法に関しては、後段で詳細に説明する。
【０１２５】
本発明のトナーは、転写性と現像性をバランス良く改善するために、以下のような形状を有する必要がある。即ち、トナーの個数基準の粒径頻度分布における円相当個数平均径が２〜１０μｍであり、円形度頻度分布における平均円形度が０．９５０〜０．９９５、好ましくは０．９６０〜０．９９５、さらに好ましくは０．９７０〜０．９９５であり、円形度標準偏差が０．０４０未満、好ましくは０．０３５未満となる様にトナーの粒子形状を精密に制御することにより、転写性と現像性をバランス良く改善することができる。
【０１２６】
トナーの個数基準の粒径頻度分布における円相当個数平均径を２〜１０μｍと小粒径化することにより、画像の輪郭部分、特に文字画像やラインパターンの現像での再現性が良好なものとなる。しかし、一般にトナー粒子を小粒径化すると、必然的に微小粒径のトナーの存在率が高くなるため、トナーを均一に帯電させることが困難となり画像カブリを生じるばかりか、静電潜像担持体表面への付着力が高くなり、結果として転写残トナーの増加を招く傾向がある。
【０１２７】
しかし、本発明のトナーは、円形度頻度分布の円形度標準偏差を上記のように制御することで、現像性や転写性の環境変動に対する安定性、更には耐久性が良好なものとなる。その理由として、現像工程においてトナー担持体上にトナーの薄層が形成される際に、トナー層厚規制部材の規制力を通常よりも強くしても十分なトナーコート量を保つことができるため、トナー担持体に対するダメージを与えることなくトナー担持体上のトナーの帯電量を通常よりも高くすることが可能となるからだと考えられる。
【０１２８】
円形度頻度分布における平均円形度を０．９５０〜０．９９５、より好ましくは０．９７０〜０．９９５とすることにより、従来では困難とみなされている小粒径を呈するトナーの転写性が大幅に改善されると共に、低電位潜像に対する現像能力も格段に向上することができる。特にデジタル方式の微小スポット潜像を現像する場合に有効である。平均円形度が０．９５０未満の場合、転写性が低下するばかりか、現像性が低下する場合がある。また、平均円形度が０．９９５を超えるとトナー表面の劣化が著しいものとなり耐久性等に問題を生じる傾向がある。
【０１２９】
平均円形度が０．９５０〜０．９９５であるような球形トナーは、通常、粒子同士が点で接するようになるため、接触点での圧力が高まり、トナー粒子表面に存在する外添剤が、トナーに埋め込まれてしまいやすいものであります。しかしながら、本願発明のトナーは、トナー粒子表面にジエン単量体による網目構造が形成されているため、表面強度が高く、外添剤の埋め込みが抑制される。このため、長期にわたって使用した場合においても、初期の優れた特性が維持されるようになる。この傾向は、平均円形度が０．９７０〜０．９９５であるトナーにおいて、特に顕著となる。
【０１３０】
また、多種の転写材に対応させるために転写工程で中間転写方式を行う場合、転写工程が実質２回行われるため、一般には、転写効率低下率は著しくトナーの利用効率の低下を招く問題となる。デジタルフルカラー複写機やプリンタにおいては、色画像原稿を予めＢ（ブルー）フィルター、Ｇ（グリーン）フィルター、Ｒ（レッド）フィルターを用い色分解した後、感光体上に２０〜７０μｍのドット潜像を形成し、Ｙ（イエロー）トナー、Ｍ（マゼンタ）トナー、Ｃ（シアン）トナー、Ｂ（ブラック）トナーの各色トナーを用いて減色混合作用を利用し、原稿に忠実な多色カラー画像を再現する必要がある。この際、原稿やCRTの色情報に対応して感光体上または中間転写体上に、Yトナー、Mトナー、Cトナー、Bトナーの各カラートナーが多量に乗るため、本発明使用される各カラートナーは、極めて高い転写性が要求される。このようなより高いレベルの要求を満たすためには、前述したトナーの平均円形度が０．９５０〜０．９９５、好ましくは０．９７０〜０．９９５であり、円形度標準偏差が０．０４０未満、好ましくは０．０３５未満であることが好ましい。
【０１３１】
また、本発明のトナーは、上記フロー式粒子像測定装置で計測される個数基準の円相当径−円形度スキャッタグラムにおいて、円形度０．９５０未満のトナーが１５個数％以下であることが好ましい。円形度０．９５０未満のトナーが１５個数％を越えて含まれていると、転写残トナーが増加する傾向があるため好ましくない。
【０１３２】
本発明における円形度は、粒子の形状を定量的に表現する簡便な方法として用いたものであり、本発明では東亜医用電子社製フロー式粒子像分析装置ＦＰＩＡ−１０００を用いて粒子形状の測定を行い、円形度を下式により求める。更に下式で示すように、測定された全粒子の円形度の総和を全粒子数で除した値を平均円形度と定義する。
【０１３３】
【外５】

【０１３４】
ここで、「粒子投影面積」とは二値化されたトナー粒子像の面積であり、「粒子投影像の周囲長」とは該トナー粒子像のエッジ点を結んで得られる輪郭線の長さと定義する。
【０１３５】
なお、本発明で用いている測定装置である「ＦＰＩＡ−１０００」は、各粒子の円形度を算出後、平均円形度及び円形度標準偏差の算出に当たって、粒子を得られた円形度によって、円形度０．４００〜１．０００を０．０１０間隔で、０．４００以上０．４１０未満、０．４１０以上０．４２０未満…０．９９０以上１．０００未満及び１．０００の如くに６１分割した分割範囲に分け、分割点の中心値と頻度を用いて平均円形度及び円形度標準偏差の算出を行う算出法を用いている。
【０１３６】
この算出法で算出される平均円形度及び円形度標準偏差の各値と、上述した各粒子の円形度を直接用いる算出式によって算出される平均円形度及び円形度標準偏差の各値との誤差は、非常に少なく、実質的には無視できる程度であるため、本発明においては、算出時間の短絡化や算出演算式の簡略化の如きデータの取り扱い上の理由で、上述した各粒子の円形度を直接用いる算出式の概念を利用し、一部変更したこの様な算出法を用いている。
【０１３７】
本発明における円形度は、粒子の凹凸の度合いを示す指標であり、粒子が完全な球形の場合に１．０００を示し、表面形状が複雑になる程、円形度は小さな値となる。
【０１３８】
また、円相当径とは、
【０１３９】
【外６】

【０１４０】
と定義される値であり、円相当個数平均径（Ｄ１）とは、個数基準によるトナーの円相当径の平均値を表し、粒度分布の分割点ｉでの粒径（中心値）をｄｉ、頻度をｆｉとすると下式の如く表される。
【０１４１】
【外７】

【０１４２】
本発明における粒度分布の分割点は、下表に示されるとおりである。
【０１４３】
【表１】

【０１４４】
具体的な測定方法としては、例えば、容器中に予め不純固形物などを除去したイオン交換水1０ｍ１を用意し、その中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルホン酸塩を加えた後、更に測定試料０．０２ｇを加え、均一に分散させる。分散させる手段としては、超音波分散機ＵＨ−５０型（エスエムテー社製）に振動子として直径５ｍｍのチタン合金チップを装着したものを用い、５分間分散処理を用い、測定用の分散液とする。その際、上記分散液の温度が４０℃以上とならない様に適宜冷却する。
【０１４５】
円形度及び円相当径の具体的な測定方法としては、ノニオン型界面活性剤約０．１ｍｇを溶解している水１０ｍｌにトナー約５ｍｇを分散させ分散液を調製し、超音波（２０ｋＨｚ、５０Ｗ）を分散液に５分間照射し、分散液濃度を５０００〜２００００個／μｌとして、上記フロー式粒子像測定装置を用い、０．６０μｍ以上１５９．２１μｍ未満の円相当径を有する粒子の円形度分布を測定する。
【０１４６】
測定の概略は、東亜医用電子社（株）発行のＦＰＩＡ−１０００のカタログ（１９９５年６月版）、測定装置の操作マニュアル及び特開平８−１３６４３９号公報に記載されているが、以下の通りである。
【０１４７】
試料分散液は、フラットで扁平な透明フローセル（厚み約２００μｍ）の流路（流れ方向に沿って広がっている）を通過させる。フローセルの厚みに対して交差して通過する光路を形成するように、ストロボとＣＣＤカメラが、フローセルに対して、相互に反対側に位置するように装着される。試料分散液が流れている間に、ストロボ光がフローセルを流れている粒子の画像を得るために１／３０秒間隔で照射され、その結果、それぞれの粒子は、フローセルに平行な一定範囲を有する２次元画像として撮影される。それぞれの粒子の２次元画像の面積から、同一の面積を有する円の直径を円相当径として算出する。それぞれの粒子の２次元画像の投影面積及び投影像の周囲長から上記の円形度算出式を用いて各粒子の円形度を算出する。本発明においては、０．６０μｍ以上１５９．２１μｍ未満の円相当径を有する粒子を測定の対象とする。
【０１４８】
トナーの形状を上記のようにするには、具体的には、重合法トナーにおける場合は重合方法や重合温度を調整すればよく、粉砕トナーにおいては粉砕条件を調整すればよい。
【０１４９】
本発明の乾式トナーのテトラヒドロフラン（ＴＨＦ）可溶分は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定される分子量分布において、メインピーク分子量が２×１０³〜１×１０⁵の範囲であり、且つＴＨＦ不溶分が５〜６０質量％である。
【０１５０】
本発明において、トナー中の結着樹脂の分子量は、ＧＰＣにおける分子量分布からポリスチレン換算分子量として求めた値である。本発明のトナーにおいては、ＴＨＦ可溶分のＧＰＣにより測定される分子量分布が、２×１０³〜１×１０⁵の範囲にメインピーク分子量を有しており、好ましくは５×１０³〜５×１０⁴の範囲に有する。メインピーク分子量が２×１０³よりも低いと帯電特性に悪影響がでる場合があり、また高温下で保存された場合、ジエン単量体を含有する樹脂成分がトナー表面に移行し、耐ブロッキング性に悪影響を及ぼすことがある。メインピーク分子量が１×１０⁵を越えると溶融粘度が高くなりすぎ、定着性に問題を生じたり、ジエン単量体を含有する樹脂成分のフレキシビリティーを効果的に発現させることが出来ず、低温オフセットが発生したりしてしまう。
【０１５１】
本発明において、トナーのＴＨＦ可溶分とは、ＴＨＦに可溶であるトナー成分であるが、具体的には、結着樹脂が主成分であり、ワックス成分等も含む。トナーのＴＨＦ可溶分は、以下のようにして得ることができる。
【０１５２】
トナー試料をＴＨＦ中に入れ、数時間放置した後、十分に振とうし、ＴＨＦと良く混ぜ（試料の合一体がなくなるまで）、更に１２時間以上静置する。このときＴＨＦ中への放置時間が２４時間以上となるようにする。その後、サンプル処理フィルター（ポアサイズ０．２μｍ、例えば、マイショリディスクＨ−２５−５：東ソー社製、エキクロディスク２５ＣＲ：ゲルマンサイエンス ジャパン社製などが利用できる）を通過させることによってＴＨＦ可溶分を分取することができる。得られた溶液の濃度を結着樹脂成分が０．５〜５．０ｍｇ／ｍｌとなるように調整しＧＰＣの試料とする。
【０１５３】
本発明において、トナーのＴＨＦ可溶分のＧＰＣによるクロマトグラムの分子量分布は、次の条件で測定することができる。
【０１５４】
すなわち、４０℃のヒートチャンバ中でカラムを安定化させ、この温度におけるカラムに、溶媒としてＴＨＦ（テトラハイドロフラン）を毎分１ｍｌの流速で流し、ＴＨＦ可溶トナー試料溶液（上記ＴＨＦ可溶分）を約１００μｌ注入して測定する。トナー試料の分子量測定にあたっては、試料の有する分子量分布を、数種の単分散ポリスチレン標準試料により作成された検量線の対数値とカウント数との関係から算出する。
【０１５５】
検量線作成用の標準ポリスチレン試料として、たとえば、東ソー社製ＴＳＫスタンダードポリスチレンF-850、F-450、F-288、F-128、F-80、F-40、F-20、F-10、F-4、F-2、F-1、A-5000、A-2500、A-1000、A-500を用いて検量線を作成することができ、少なくとも10点程度の標準ポリスチレン試料を用いるのが適当である。
【０１５６】
また、検出器には、ＲＩ（屈折率）検出器とＵＶ（紫外線）検出器とを直列に配列したものを用いる。なおカラムとしては、市販のポリスチレンゲルカラムを複数本組み合わせるのが良く、本発明では例えば、昭和電工社製のshodex GPC KF−801、802、803、804、805、806、807、800Pの組み合わせを挙げることができる。装置には、東ソー社製の高速GPC HPLC8120 GPCを使用することができる。
【０１５７】
また本発明において、ＴＨＦ不溶分が５〜６０質量％でなければならない。好ましくは、５〜５５質量％である。ＴＨＦ不溶分が５質量％以上存在する場合に、ジエン単量体によるトナー表面近傍での３次元化が良好に行われていると考えられる。ＴＨＦ不溶分が５質量％未満であると、トナー表面近傍での３次元化が不十分であるため、高温下での耐久性に劣るようになってしまい、またトナーの帯電安定性を長期間に亘って保持しにくくなる。一方、ＴＨＦ不溶分が６０質量％を越えると、ジエン単量体を含有する結着樹脂の有するフレキシビリティーに由来する特長が発揮されにくくなるため、定着時にオフセットが発生しやすくなる。
【０１５８】
本発明おいては、ジエン単量体によりＴＨＦ不溶分を比較的容易にコントロールすることができる。即ち、トナー中のジエン単量体含有量を多くすれば、ＴＨＦ不溶分を多くすることができる。
【０１５９】
但し、本発明のトナーのＴＨＦ不溶分は、ジエン単量体の量のみによって決まるのではなく、粉砕法によってトナーを製造する場合には、含有するジエン単量体量や、トナー粒子表面近傍の未反応の二重結合を反応させるために添加される重合開始剤量等によって決まる。この際には、ジエン単量体量による影響が大きい傾向がある。また、懸濁重合によってトナーを製造する場合には、ジエン単量体量、重合反応や反応処理する際の重合開始剤量、さらには重合温度や反応処理する際の温度等の影響を受ける。重合開始剤の使用量等を変えると、ＴＨＦ可溶分のピーク分子量にも大きな影響を与えることになるので、本発明においてＴＨＦ不溶分の調整を行う際には、ＴＨＦ可溶分のピーク分子量に関しても配慮しなくてはならない。
【０１６０】
また、それ以外にも重合性二重結合を２つ以上有する単量体を含有させることによっても同様な効果を得ることが可能である。
【０１６１】
そのような単量体として、o(m-,p-)-ジビニルベンゼン、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、トリエチレングリコール（メタ）アクリレート、o(m-,p-)-ジビニルシクロへキサン、トリメチロールエタントリ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレートを例示することが出来る。これらの単量体は単独で用いても、２種以上を組み合わせて用いても何ら差し支えない。
【０１６２】
本発明においてトナーのＴＨＦ不溶分とは、トナー粒子中の結着樹脂組成物のＴＨＦに対して不溶性となった結着樹脂成分の質量割合のことであり、架橋成分を含む結着樹脂組成物の架橋の程度を示す目安となる。しかし、ＴＨＦ不溶分が０質量％であっても必ずしも架橋していないという訳ではない。本発明においてＴＨＦ不溶分とは、以下のように測定された値をもって定義する。
【０１６３】
即ち、トナーが非磁性トナーの場合には顔料の含有率などを、磁性トナーの場合には顔料及び磁性体の含有率などを、予め公知の方法で測定しておく。次に、トナー０．５〜１．０ｇの一定量を秤量し（Ｗ₁ｇ）、円筒濃紙（東洋濃紙製 No.86R）に入れてソックスレー抽出器にかけ、溶媒としてＴＨＦ１００〜２００ｍｌを用いて２０時間抽出し、溶媒によって抽出された可溶成分をエバポレートした後、１００℃で数時間真空乾燥し、ＴＨＦ可溶樹脂成分量を秤量する（Ｗ₂ｇ）。そして、上記トナー一定量中に含まれている顔料や磁性体のうち、THFに可溶な成分の質量をＷ₃ｇ、ＴＨＦに不溶な成分の質量をＷ₄ｇとすると、以下の式に従って樹脂組成物中のＴＨＦ不溶分を算出することができる。
【０１６４】
【外８】

【０１６５】
＜２＞本発明の乾式トナーの製造方法
本発明のトナーの製造方法としては様々な方法が挙げられるが、一部又は全体が重合法によって製造されることが好ましい。トナーの一部が重合法により製造されるとは、溶液重合、塊状重合、懸濁重合、乳化重合、ブロック共重合、グラフト化などを応用して結着樹脂のみを重合することにより得た後、粉砕法、溶融スプレー法等によってトナー粒子を得る方法であり、トナー全体が重合法により製造されるとは、モノマーに着色剤、電荷制御剤等を添加混合し、その後重合を行ってトナー粒子を得る手法であり、結着樹脂の製造とトナー製造を同時に行う方法のことである。
【０１６６】
本発明のトナーを粉砕法により製造する場合には、上記ジエン単量体成分含有樹脂、ワックス成分、着色剤（磁性体でも可）、必要に応じて併用される樹脂、荷電制御剤及びその他の添加剤等を、へンシェルミキサー或いはボールミルの如き混合機より充分混合してから加圧ニーダーやエクストルーダーの如き熱混練機を用いて溶融混練し、冷却固化後に固形物を機械的又はジェット気流下でターゲットに衝突させ、所望のトナー粒径に微粉砕化する。その後、必要に応じてトナー粒子の平滑化及び球形化処理を行う。次いで、分級工程により粒度分布をシャープにする。さらに、分級粉をシリカ微粒子の如き外添剤とへンシェルミキサーのごとき混合機により充分混合することで本発明のトナーを得ることができる。本発明の製造方法としては、例えば球形化処理したトナー粒子に重合開始剤、および必要に応じて添加される重合性単量体にてトナー表面に存在するジエン単量体成分含有樹脂を反応させることによりトナー粒子表面近傍の強度を増すことができる。
【０１６７】
本発明のトナーに含有される結着樹脂を構成するジエン単量体成分含有樹脂は、トナー中にいかなる形状、状態で含有されていても良く、結着樹脂を構成する他の樹脂と相溶した状態であっても、相分離した状態であっても良い。粉砕法でトナーを製造する場合には、溶融混練工程において、他の樹脂と共にジエン単量体成分含有樹脂が溶融されている必要はなく、溶融された他の樹脂の中に分散した状態あっても良い。このような場合には、トナー中のジエン単量体成分含有樹脂は併用される他の樹脂中に分散された状態になる。ジエン単量体成分含有樹脂と他の樹脂をキシレン等の溶剤を用いて予め均一に溶解混合した場合には、ジエン単量体成分含有樹脂が他の樹脂中に微分散、または場合により相溶化される。このような均一化操作を実施せずに、ジエン単量体成分含有樹脂の粉末と他の樹脂を混練し、かつ、ジエン単量体成分含有樹脂の溶融温度未満で混練を行う場合には、ジエン単量体成分含有樹脂が粉末の状態でトナー中に分散されることとなるため、１μｍ以下、好ましくは０．５μｍ以下に微粉砕したジエン単量体成分含有樹脂を用いるのがよい。
【０１６８】
その他のトナーの製造方法として、分級工程にて得られた分級粉に流動化剤とともに、あるいは別々に超微粉化したジエン単量体成分含有樹脂を加えて充分混合し、トナー粒子表面にジエン単量体成分含有樹脂を固着させる方法もあり、この場合、分級粉中の樹脂にジエン単量体成分含有樹脂が含まれていても良いし、全く含まれていなくても良い。また、固着させた後にトナー粒子の平滑化及び球形化処理を行っても良い。さらに、固着後、あるいは球形化処理後のトナー粒子に重合開始剤、および必要に応じて添加される重合性単量体を吸着させて、表面に存在するジエン単量体成分含有樹脂と反応させることによりトナー粒子表面近傍の強度を増すことができる。
【０１６９】
また、ジエン単量体成分含有樹脂を有さないコアとなるトナー粒子に、ジエン単量体成分含有樹脂を有する単量体成分と重合開始剤からなる組成物を吸着させて、同様な効果を得ることも可能である。
【０１７０】
その他の方法として、特公昭５６−１３９４５号公報に記載の方法と同様に、ディスク又は多流体ノズルを用い、結着樹脂を構成するジエン単量体成分含有樹脂を含む溶融混合物を空気中に霧化し球形トナーを得る溶融スプレー法が挙げられる。また、ジエン単量体を含有しない重合体粒子を重合法により製造し、その後、重合体粒子の表面に微粒子状のジエン単量体成分を含む樹脂を付着させ、必要に応じて粒子の平滑化および球形化処理を行う方法が挙げられる。
【０１７１】
いずれの場合も、結着樹脂は、溶液重合、塊状重合、懸濁重合、乳化重合、ブロック共重合、グラフト化などを応用して重合することにより得られる。
【０１７２】
本発明のトナー全体を重合法により製造する場合には、単量体組成物にジエン単量体成分含有樹脂を溶解し、特公昭３６−１０２３１号公報、特開昭５９−６１８４２号公報に述ベられているような懸濁重合方法を用いて直接トナーを製造する方法、単量体には可溶で、得られる重合体には不溶な水系有機溶剤を用いて直接トナー製造する分散重合法または水溶性重合開始剤存在下で直接重合しトナーを製造するソープフリー重合法に代表される乳化重合法により、本発明のトナーを得ることができる。また、ジエン単量体成分含有樹脂を有さないコア粒子にジエン単量体成分含有樹脂と、その他の樹脂の単量体（組成物）により表面層を設ける方法も採用することができ、あるいはジエン単量体成分含有樹脂を有するトナー粒子に重合開始剤、好ましくは親水性の高い重合開始剤にて表面に存在するジエン単量体成分含有樹脂をトナー粒子中に残存する、あるいは必要に応じて添加された単量体成分と反応させることによりトナー粒子表面近傍の強度を増すための工程を入れることが好適に用いられる。その際にジエン単量体成分含有樹脂と重合性単量体を併せて添加することも好ましい。
【０１７３】
また、加圧下にて、ジエン単量体成分含有樹脂、他の重合性ビニル系単量体、ワックス、着色剤を含有する重合性単量体組成物を懸濁重合、乳化重合あるいは分散重合することにより、本発明のトナーを得ることができる。
【０１７４】
上述したトナーの製造方法のうち、溶融スプレー法は、得られるトナーの粒度分布が広くなりやすく、分散重合法は、得られるトナーは極めてシャープな粒度分布を示すが、使用する材料の選択の幅が狭く、また有機溶剤を利用するため廃溶剤の処理や溶剤の引火性に関する観点から製造装置が複雑で煩雑化しやすい。また、乳化重合法は、トナーの粒度が比較的揃うという利点があるが、一般に生成する粒子の粒度が非常に細かく、トナーとしてそのまま使用することは困難であり、また、使用した水溶性重合開始剤の末端や乳化剤がトナー粒子表面に存在し、トナーの環境特性を低下させることがある。
【０１７５】
一方、粉砕法によって得られたトナー粒子を平滑化及び球形化処理することにより製造する方法、或いは懸濁重合法による製造が、トナーの円形度や円形度標準偏差を希望する範囲に収めることが容易であり、好ましい方法であるが、本発明では懸濁重合法による製造が最も好ましい製造方法である。
【０１７６】
また、懸濁重合法により本発明のトナーを製造する方法は、特にトナー粒子の形状制御が容易であり、また、ジエン単量体成分含有樹脂を結着樹脂の原料となる単量体組成物中に溶解すれば良いので、使用できる樹脂の種類が多く特に好ましい製造方法である。
【０１７７】
本発明においては、上述した如く、種々の製造方法を用いることができるが、重要なことは、粉砕法であれば樹脂の粉砕後、重合法であれば後述する重合転化率の時点で、トナー粒子に含有される成分の有する未反応の二重結合、特にジエン単量体に由来する成分の有する二重結合を反応させて、トナー粒子表面に架橋を形成することである。
【０１７８】
本発明においては、次の如き製造方法が特に好ましい。
【０１７９】
重合性ビニル系単量体中に、ジエン単量体成分含有樹脂、着色剤、ワックス、ラジカル重合開始剤及び必要に応じてその他の添加剤を加え、ホモジナイザー、超音波分散機等によって、均一に溶解又は分散せしめて重合性単量体組成物を調製する。通常の攪拌機又はホモミキサー、ホモジナイザーを用いて、分散安定剤を含有する水系媒体に該重合性単量体組成物を分散せしめる。好ましくは重合性単量体組成物の液滴が所望のトナー粒子のサイズを有するように攪拌速度、攪拌時間を調整し、造粒する。その後、分散安定剤の作用により、粒子状態が維持され、且つ粒子の沈降が防止される程度の攪拌を行いながら、水系媒体中で重合性ビニル系単量体を重合してトナー粒子を生成する。重合反応の転化率が１０〜９５質量％の範囲にあるときに、ラジカル重合開始剤を新たに添加して、トナー粒子の表面近傍の強度を増す方法が好ましく挙げられる。
【０１８０】
本発明において、重合開始剤としては、例えば、2,2'-アゾビス-(2,4-ジメチルバレロニトリル)、2,2'-アゾビスイソブチロニトリル、1,1'-アゾビス(シクロヘキサン-1-カルボニトリル)、2,2'-アゾビス-4-メトキシ-2,4-ジメチルバレロニトリル、アゾビスイソブチロニトリルの如きアゾ系重合開始剤及びジアゾ系重合開始剤；ベンゾイルパーオキサイド、メチルエチルケトンパーオキサイド、ジイソプロピルパーオキシカーボネート、クメンヒドロパーオキサイド、2,4-ジクロロベンゾイルパーオキサイド、ラウロイルパーオキサイドの如き過酸化物系重合開始剤の如きラジカル重合開始剤が好ましく用いられる。重合開始剤の使用量は、目的とする重合度により変化するが一般的には重合性単量体に対し０．５〜２０質量％用いられる。重合開始剤の種類は、重合法により若干異なるが、十時間半減期温度を参考に、上記重合開始剤のうちから選ばれる１つ又は２つ以上の組み合わせで使用される。
【０１８１】
重合反応の転化率が１０〜９５質量％の範囲にあるときに新たに添加される重合開始剤としては、上述した如き油溶性の重合開始剤であっても構わないが、下記の水溶性のラジカル重合開始剤を用いることもできる。
【０１８２】
水溶性のラジカル重合開始剤としては、例えば、過硫酸ナトリウム、過硫酸カリウム、過硫酸アンモニウムの如き重合開始剤が挙げられ、これらの１つ又は２つ以上の組み合わせを用いることが可能である。水溶性のラジカル重合開始剤であると、製造時の添加が容易となり水溶液で添加可能であるため利用しやすく好ましい。さらに、水溶性、或いは親水性の高い重合開始剤は、トナー粒子表面に存在するジエン単量体含有樹脂に効率良くトナー粒子に作用するため、この点からも好ましい。
【０１８３】
逆に、油溶性のラジカル重合開始剤は、水に乳化、あるいは分散させて添加することが可能であるため、重合開始剤の選択肢を拡げて反応性を制御することが出来るという観点においては好ましい。
【０１８４】
上記ラジカル重合開始剤を新たに添加する際の使用量は、目的とする重合度により変化するが重合性単量体に対し０．５〜１０質量％の範囲で用いられることが好ましい。
【０１８５】
上記水系媒体としては、水、水／アルコール混合溶媒が挙げられ、好ましくは水が用いられる。懸濁重合法においては、通常、重合性単量体組成物１００質量部に対して、水１００〜５０００質量部を分散媒体として使用するのが好ましい。
【０１８６】
本発明のトナーの製造方法において、重合反応の転化率が１０〜９５質量％の範囲にあるときに、ラジカル重合開始剤を新たに添加することが好ましいが、１０質量％に到達する前に新たに添加すると、重合反応の転化率が非常に低いため、粒子の形状が安定していない状態で重合性単量体に対する重合開始剤量が増加することになり、得られる結着樹脂成分のピーク分子量が低くなりすぎることがあるため好ましくない。ラジカル重合開始剤を新たに添加するタイミングとしてより好ましくは、転化率が２０〜９５質量％、特に２５〜９０質量％の範囲のときである。
【０１８７】
重合反応の転化率の計算は、例えば、以下のように測定することができる。
【０１８８】
ガスクロマトグラフを用いて系内に残存している予め作成しておいた検量線から未反応の重合性単量体を定量し、それを未転化率（％）として定義し、１００から減じた値を転化率として求める。具体的には、以下の条件で内部標準法により測定することができる。
【０１８９】
(転化率：％)＝１００−（未反応重合性単量体の量より検量線から求められる未転化率）
サンプル：試料（重合反応液）５μｌとジメチルフォルムアミド１μｌとをバイアル瓶に入れ、密閉したものを用いる。
測定装置：HP6890(HP製)
キャリアガス：工業用純ヘリウム
スプリット(スプリット比100:1)、線速度35cm/秒
カラム：HP-INNOWax内径0.2mm、長さ50m、膜厚0.4μm
昇温：４０℃で２分間、保持した後、毎分２０℃の割合で２００℃まで昇温する。
注入口温度：120℃
検出器：FlD 220℃
【０１９０】
製造方法に係る本発明は、ジエン単量体成分含有樹脂を含む結着樹脂の重合性二重結合を粒子表面近傍で反応させて三次元ネットワークを形成させることによりトナー粒子の強度を向上するための効率的な方法を提供するものであり、ラジカル重合開始剤を新たに添加する時点で、重合転化率が９５質量％を越えていると、残存する重合性単量体が非常に少なく、粒子がほぼ固まった状態で重合開始剤を新たに添加することになるため、粒子中での分子運動が極めて制限されており、ジエン単量体成分含有樹脂を含む結着樹脂の重合性二重結合をうまく反応させることが出来なくなる傾向があるため好ましくない。一方、ラジカル重合開始剤を新たに添加する時点で、重合転化率が１０質量％に達していない場合には、逆に、自由な分子運動が可能であるため、重合開始剤を新たに添加しても、粒子表面に三次元ネットワークを形成するようには、反応が起こらなくなってしまう。
【０１９１】
本発明では、新たに添加されるラジカル重合開始剤の１０時間半減期温度をＴ１（℃）、添加される際の反応系温度をＴ２（℃）とする際、５≦（Ｔ２−Ｔ１）≦３０の関係を満たすことが好ましい。この関係を満たすと効率よくラジカル重合開始剤が反応に関与するようになり好ましい。
【０１９２】
また、トナーを懸濁重合により製造する際、用いる分散安定剤としては、無機化合物として、リン酸三カルシウム、リン酸マグネシウム、リン酸アルミニウム、リン酸亜鉛、炭酸カルシウム、炭酸マグネシウム、水酸化カルシウム、水酸化マグネシウム、水酸化アルミニウム、メタケイ酸カルシウム、硫酸カルシウム、硫酸バリウム、ベントナイト、シリカ、アルミナが挙げられる。有機化合物としては、ポリビニルアルコール、ゼラチン、メチルセルロース、メチルヒドロキシプロピルセルロース、エチルセルロース、ヒドロキシエチルセルロース、カルボキシメチルセルロースのナトリウム塩、ポリアクリル酸及びその塩、デンプンが挙げられる。これら分散安定剤は、重合性単量体組成物１００質量部に対して０．２〜２０質量部を使用することが好ましい。
【０１９３】
分散安定剤として、無機化合物を用いる場合、市販のものをそのまま用いても良いが、細かい粒子を得るために分散媒体中にて上記無機化合物の微粒子を生成しても良い。例えば、リン酸三カルシウムの場合、高速攪拌下において、リン酸ナトリウム水溶液と塩化カルシウム水溶液を混合することによって得られる。
【０１９４】
これら分散安定剤の微細な分散のために、０．００１〜０．１質量部の界面活性剤を併用しても良い。これは上記分散安定剤の所期の作用を促進するためのものであり、例えば、ドデシルベンゼンスルホン酸ナトリウム、ドデシル硫酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、オレイン酸ナトリウム、ラウリン酸ナトリウム、ステアリン酸カリウム、オレイン酸カリウムの如きアニオン性界面活性剤、アルキルフェノールのエチレンオキサイド及び／又はプロピレンオキサイド付加物などのノニオン性界面活性剤、アルキルオニウム塩型のカチオン性界面活性剤、べタイン型やアミノ酸型の両性界面活性剤が挙げられる。
【０１９５】
重合反応時間としては、２〜２４時間が好ましい。２時間未満だと重合性単量体の所望の転化率とならず未反応の重合性単量体が多くその除去工程が煩雑なものとなり、２４時間を超えると反応時間が長すぎて生産性が低くなるため、２〜２４時間が好ましい。
【０１９６】
また、重合温度は４０℃以上、一般には５０〜９０℃の温度に設定すればよい。重合反応後半に昇温しても良く、さらに、未反応の重合性単量体、副生成物等を除去するために反応後半、又は、反応終了後に一部水系媒体を反応系から留去しても良い。反応終了後、生成したトナー粒子を洗浄後、ろ過により回収し、乾燥する。
【０１９７】
また、本発明におけるトナーの製造方法において、重合度を制御するため公知の架橋剤、連鎖移動剤、重合禁止剤等をさらに添加し用いても良い。
【０１９８】
重合法によってトナーを製造する場合においては、トナー粒子の粒度分布制御や粒径の制御は、分散安定剤の種類もしくは添加量、機械的装置条件（例えばローターの周速、パス回数、攪拌羽根形状、容器形状）又は、水系媒体中での固形分濃度等を制御することにより調整することが出来る。
【０１９９】
＜３＞本発明の画像形成方法
本発明の画像形成方法は、帯電部材に電圧を印加し、静電潜像担持体を帯電させる帯電工程；帯電された静電潜像担持体に、静電潜像を形成させる静電潜像形成工程；静電潜像担持体に形成された静電潜像に、トナー担持体上に担持された本発明のトナーを付着させて、トナー像を静電潜像担持体上に形成させる現像工程；静電潜像担持体上に形成されたトナー像を転写材に転写させる転写工程；及び転写材に転写されたトナー像を定着させる定着工程を有する画像形成方法である。
【０２００】
次に本発明の画像形成方法のいくつかの実施の形態を図に沿って具体的に説明するが、本発明はこれらに限定されない。
【０２０１】
図５は、一成分現像法で行われる画像形成装置を示す。
【０２０２】
本発明の画像形成方法においては、図５に示すとおり、トナー担持体と静電潜像担持体（以下、「感光ドラム」ともいう）とが、逆方向に回転してもよく、また、同方向に回転（図５において、トナー担持体２０２が矢印Ｃと反対方向に回転し、感光ドラム２０９が矢印Ｄ方向に回転する）してもよい。
【０２０３】
現像領域におけるトナー担持体表面の移動速度が、静電潜像担持体表面の移動速度に対し、１．０５〜３．０倍の速度となるように設定することが好ましい。移動速度を１．０５〜３．０倍となるように設定することで、上記トナー担持体上のトナー層は適度な攪拌効果を受けるため、静電潜像の忠実な再現が一層良好なものとなる。
【０２０４】
現像工程において、静電潜像担持体上の静電潜像とトナー担持体に薄層コートされたトナーとを接触させながら現像する際（以下、「接触現像」と略す。）には、特にトナー担持体の周速が、静電潜像担持体の周速に対し、１．０５倍未満であると、静電潜像担持体上のトナーの受ける攪拌効果が不十分となり、良好な画像品質が望めない。また、ベタ黒画像等、広い面積にわたって多くのトナー量を必要とする画像を現像する場合、静電潜像へのトナー供給量が不足し画像濃度が薄くなってしまう。周速比が高まれば高まるほど、現像部位に供給されるトナーの量は多くなる。また潜像に対しトナーの脱着頻度が多くなるため、不要な部分(非画像部)のトナーは回収され、必要な部分（画像部）には付与されるという繰り返しにより、静電潜像に忠実な画像が得られるようになる。また、本発明の画像形成方法としては、後述する現像兼クリーニング工程を適用することも可能あり、現像兼クリーニング工程において、静電潜像担持体上に密着した転写残トナーが存在する場合には、静電潜像担持体表面とトナーの付着部分を周速差により転写残トナーの帯電性を調整し、その後に電界クリーニングにより回収するという操作が重要であることから、周速比は高いほど転写残トナーの回収には都合がよい。但し、逆に周速比が３．０を超える場合には、上記の如きトナーの過剰な帯電によって引き起こされる種々の問題（トナーの過度なチャージアップによる画像濃度低下等）の他に、機械的ストレスによるトナーの劣化やトナー担持体へのトナー固着が発生または促進されることがあり好ましくない。
【０２０５】
本発明における静電潜像担持体としては、a-Se、CdS、ZnO₂、OPC、a-Siの様な光導電絶縁物質層を持つ感光ドラムもしくは感光ベルトが好適に使用される。
【０２０６】
また、ポリカーボネート樹脂、ポリエステル樹脂、アクリル系樹脂等の結着樹脂を含有する有機系感光層を有するＯＰＣ感光体（感光ドラムもしくは感光ベルト）も、転写性及びクリーニング性がよく、クリーニング不良、感光体へのトナー融着及び外添剤のフィルミングが起こりにくいため好ましい。
【０２０７】
また、本発明では、現像工程が非接触の現像方式である場合、トナー担持体の表面粗度Ｒａ(μｍ)は、０．２〜１．５であることが好ましい。表面粗度Ｒａを１．５以下とすることでトナー担持体のトナー搬送能力を抑制し、上記トナー担持体上のトナー層を薄層化すると共に、上記トナー担持体とトナーの接触回数が多くなるため、上記トナーの帯電性も改善されるので相乗的に画像品質が向上する。
【０２０８】
さらに、現像工程が接触現像の方式である場合、トナー担持体の表面形状は、その表面粗度Ｒａ（μｍ）を０．２〜３．０となるように設定すると、高画質及び高耐久性を両立できることから好ましい。上記表面粗度Ｒａは、トナー搬送能力及びトナー帯電能力と相関する。上記トナー担持体の表面粗度Ｒａが３．０を超えると、上記トナー担持体上のトナー層の薄層化が困難となることがあるばかりか、トナーの帯電性が改善されないことがあるので画質の向上は望めない。３．０以下にすることでトナー担持体表面のトナーの搬送能力を抑制し、上記トナー担持体上のトナー層を薄層化すると共に、上記トナー担持体とトナーの接触回数が多くなるため、上記トナーの帯電性も改善されるので相乗的に画質が向上する。一方、表面粗度Ｒａが０．２よりも小さくなると、トナーのコート量の制御が難しくなることがある。
【０２０９】
トナー担持体の表面粗度Ｒａを上記の範囲にするには、例えば、トナー担持体の表層の研磨状態を変えることにより可能となる。即ち、トナー担持体表面の研磨を粗く行えば、その表面粗さを大きくすることができ、表面の研磨を細かく行えば、その表面粗さを小さくすることができる。本発明において、トナー担持体の表面粗度Raは、ＪｌＳ表面粗さ「ＪＩＳ B ０６０１」に基づき、表面粗さ測定器（サーフコーダＳＥ−３０Ｈ、株式会社小坂研究所社製）を用いて測定される中心線平均粗さである。具体的には、粗さ曲線からその中心線の方向に測定長さaとして２．５ｍｍの部分を抜き取り、この抜き取り部分の中心線をＸ軸、縦倍率の方向をＹ軸、粗さ曲線をｙ＝ｆ（ｘ）で表したとき、次式によって求められる値をマイクロメートル（μｍ）で表したものをいう。
【０２１０】
【外９】

【０２１１】
上記のような性質を有するトナー担持体として、表面に弾性層を有する、いわゆる弾性ローラが好ましく用いられる。
【０２１２】
弾性ローラの構成としては、芯金を用い、その外周に弾性層を被覆したものであり、弾性層の材料としては、シリコーンゴム、テフロンゴムが好ましく用いられる。
【０２１３】
使用される弾性層の硬度としては、アスカーＣ硬度における２０〜６５度のものが好適に使用される。
【０２１４】
また、トナー担持体の抵抗としては、体積抵抗値で１０²〜１０⁹Ω・cm程度の範囲が好ましい。静電潜像担持体の表面にピンホール等がある場合などに、１０²Ω・cmよりも低いと過電流が流れる恐れがあり、反対に１０⁹Ω・cmよりも高い場合は、摩擦帯電によるトナーのチャージアップが起こりやすく、画像濃度の低下を招きやすい。弾性層の体積抵抗値を上記範囲にするには、弾性材料に、カーボンブラック、酸化鉄の如き導電性付与剤を配合分散して調整することができる。
【０２１５】
トナー担持体上のトナー量は、規制部材により規制されるが、トナー規制部材としては、トナー担持体と一定間隔をおいて配置される規制部材や、トナー担持体と当接される弾性体からなる規制部材が挙げられる。
【０２１６】
トナー担持体上のトナー量は、０．１乃至１．５ｍｇ／ｃｍ²が好ましく、０．２乃至０．９ｍｇ／ｃｍ²がより好ましい。０．１ｍｇ／ｃｍ²よりも少ないと十分な画像濃度が得られにくく、１．５ｍｇ／ｃｍ²よりも多くなると個々のトナー粒子を均一に摩擦帯電することが難しくなり、カブリを生じる要因となる。
【０２１７】
本発明において、トナー担持体と一定間隔をおいて配置される規制部材としては、金属ブレード、磁性ブレードの如き強磁性金属ブレードであるドクターブレード、又は金属、樹脂、セラミックなどを用いた剛体ローラもしくはスリーブを用いても良く、それらの内部に磁気発生手段を入れても良い。
【０２１８】
また、トナー担持体と対向して当接される弾性体からなる規制部材としては、トナーを圧接塗布して薄層化するものであれば特に制限されないが、例えば、弾性ブレードや弾性ローラの如き弾性体が挙げられるが、弾性体からなるブレードが好ましい。
【０２１９】
トナー担持体と対向して当接されるとは、例えば、弾性ブレードの上辺部側である基部をトナー容器に固定し、可変部側をブレードの弾性に抗してトナー担持体の順方向あるいは逆方向にたわめた状態にして、ブレード内面側（逆方向の場合には外面側）をトナー担持体表面に適度の弾性押圧を持って当接させることである。このような装置によると、環境の変動よる影響が小さく、安定、且つ緻密なトナー層がトナー担持体上に形成されるようになる。その理由は必ずしも明確ではないが、上記弾性体によって上記トナー担持体表面と強制的に摩擦されるためトナーの環境変化による挙動の変化に関係なく常に同じ状態でトナーに対する帯電の付与が行われるためと推測される。
【０２２０】
図５に、トナー層厚を規制するための規制部材として、現像ブレード２０１を示す。この現像ブレード２０１はトナー層を介してトナー担持体２０２に接触している。この時の接触圧は、５〜５０ｇ／ｃｍが好ましい範囲である。
【０２２１】
５ｇ／ｃｍよりも小さいとトナーコート量の制御が困難となることに加え、トナーに対しての均一な摩擦帯電の付与も難しくなることがあり、カブリが生じる原因となる。一方、５０ｇ／ｃｍよりも大きくなるとトナー粒子が過剰な負荷を受けることがあるため、粒子の変形や、現像ブレードあるいはトナー担持体へのトナーの融着等が発生しやすくなり、好ましくない。
【０２２２】
弾性の規制部材には所望の極性にトナーを帯電させるのに適した摩擦帯電系列の材質を選択することが好ましく、シリコーンゴム、ウレタンゴム、NBRの如きゴム弾性体、ポリエチレンテレフタレートの如き合成樹脂弾性体、ステンレス、鋼、リン青銅の如き金属弾性体の中から選択して用いることができる。また、それらの複合体であっても良い。
【０２２３】
また、弾性の規制部材とトナー担持体に耐久性が要求される場合には、金属弾性体のスリーブ当接部に樹脂やゴムを当たるように貼り合わせたり、コーティング塗布したものが好ましい。
【０２２４】
更に、弾性の規制部材中に有機物や無機物を添加してもよく、溶融混合させても良いし、分散させても良い。例えば、金属酸化物、金属粉、セラミックス、炭素同素体、ウィスカー、無機繊維、染料、顔料、界面活性剤を添加することにより、トナーの帯電性をコントロールできる。特に、弾性体がゴムや樹脂の如き成型体の場合には、シリカ、アルミナ、チタニア、酸化錫、酸化ジルコニア、酸化亜鉛の如き金属酸化物微粉末、カーボンブラック、一般にトナーに用いられる荷電制御剤を含有させることも好ましい。
【０２２５】
また、トナーへのほぐし作用のため、トナー担持体上のトナー量を規制する規制部材である現像ブレード、トナー担持体にトナーを供給する供給部材である供給ローラ、ブラシ部材に直流電界および／又は交番電界を印加することも好ましい構成である。ほぐし作用が働くことによって、トナー担持体における均一薄層塗布性、均一帯電性がより向上し、供給部位におけるトナーの供給・はぎとりがよりスムーズになされるため、十分な画像濃度を有する良質の画像を得ることができるようになる。
【０２２６】
本発明における現像工程において、静電潜像担持体とトナー担持体がある一定の間隔を有し、両者間に交番電界を形成することにより現像することも可能であり、このような現像方法として、具体的には、ジャンピング現像方法が挙げられる。上記で「一定の間隔」とは、トナー担持体上のトナー層の厚さ以上に設定されていればよい。静電潜像担持体とトナー担持体との間に交番電界を形成するには、例えば、両者間に交流バイアスを印加することにより行いうる。
【０２２７】
上記の接触現像方法における現像工程としては、例えば図６に示すような現像装置３１を具備する現像手段を用い現像を行うことができる。具体的には、電源３６により、直流あるいは交流バイアスをトナー担持体３７に印加しつつ、塗布ローラ３２より供給され規制部材である現像ブレード３３でトナー層厚を規制されたトナー３４が感光ドラム３５に接触している状態で、現像が行われる。トナー担持体としては、弾性ローラを用いることが好ましい。交番電界を用いる場合には、三角波、矩形波、正弦波あるいはデューティー比（Duty比）を変えた波形や、定期的に交番をオフした波形等種々選択して用いることもできるが、本発明においては感光ドラムへの電圧的負荷の少ない直流電界が好適に使用され、印加バイアスは感光ドラム上の暗部電位（帯電工程直後の電位）と明部電位（露光工程後の露光部の電位）のと間の適当な値に設定される。
【０２２８】
本発明の画像形成方法における現像工程の条件としては、ジャンピング現像方法又は接触現像方法のいずれの場合においても反転現像方法を用いることが好ましい。さらに、転写工程において静電潜像担持体上に残存した転写残トナーを、現像工程中にトナー担持体により回収する現像兼クリーニング工程（「クリーナレスプロセス」ともいう）を併用することは、装置の大幅な小型化が可能となるため好ましい。
【０２２９】
即ち、反転現像の場合、この現像兼クリーニング工程は、現像バイアスによる静電潜像担持体の暗部電位からトナー担持体にトナーを回収する電界と、トナー担持体から静電潜像担持体の明部電位へトナーを付着させる電界の作用でなされる。
【０２３０】
現像時のみでなく、転写工程後であり現像工程の前に、直流あるいは交流のバイアスを転写残トナーに印加し、静電潜像担持体上の残余のトナーを回収出来るような電位に制御しても良い。このとき直流バイアスは、明部電位と暗部電位の間に位置する。
【０２３１】
また、上記接触現像方法の場合、現像兼クリーニング工程においては、静電潜像担持体である感光体と、トナーを介して感光体表面に対向する弾性ローラとの間に働く電界によって、転写残トナーのクリーニングが行われるので、弾性ローラ表面あるいは表面近傍が電位をもち、感光体表面とトナー担持体表面の狭い間隙で電界を有する必要性がある。このため、弾性ローラの弾性ゴムが中抵抗領域に抵抗制御されて感光体表面との導通を防ぎつつ電界を保つか、または導電性ローラの表面層に薄層の絶縁層を設ける必要がある。さらには、導電性ローラ上に感光体表面に対向する側を絶縁性物質により被覆した導電性樹脂スリーブあるいは、絶縁性スリーブで感光体に対向しない側に導電層を設けた構成も可能である。また、トナー担持体として剛体ローラを用い、感光体をベルトのごときフレキシブルな物とした構成も可能である。トナー担持体としての上記ローラの抵抗としては１０²〜１０⁹Ω・cmの範囲が好ましい。
【０２３２】
本発明の画像形成方法において、現像兼クリーニング工程を用いた場合の単色での画像形成方法について図５を用いて説明する。
【０２３３】
図５において、現像装置２００はトナー２０４を収容しており、静電潜像担持体である感光体２０９と接触して矢印Ｃ方向に回転するトナー担持体２０２と、トナー量の制及び帯電付与のための規制部材である現像ブレード２０１と、トナー２０４をトナー担持体２０２に付着させ且つトナー担持体２０２との摩擦でトナーへの帯電付与を行うため矢印Ｂ方向に回転する塗布ローラ２０３を具備している。トナー担持体２０２には現像バイアス電源２１７が接続されている。塗布ローラ２０３にもバイアス電源２１８が接続されており、負帯電性トナーを使用する場合は現像バイアスよりも負側に、正帯電性トナーを使用する場合は現像バイアスよりも正側に電圧が設定される。
【０２３４】
転写装置２０６には感光体２０９と反対極性の転写バイアス電源２１６が接続されている。ここで、感光体２０９とトナー担持体２０２の接触部分における回転方向の長さ、いわゆる現像当接幅は０．２〜８．０ｍｍが好ましい。０．２ｍｍ未満では現像量が不足して満足な画像濃度が得られず、転写残トナーの回収も不十分となることがある。８．０ｍｍを越えてしまうと、トナーの供給量が過剰となり、カブリが生じやすく、また、感光体の摩耗にも悪影響を及ぼすことがある。
【０２３５】
一次帯電部材としての帯電ローラ２１０は、感光体２０９に接触して直接帯電を行う。一次帯電部材２１０には、感光体２０９表面を一様に帯電するようにバイアス電源２１５が接続されている。ここで用いている一次帯電部材２１０は、中心の芯金２１０ｂとその外周を形成した導電性弾性層２１０ａとを基本構成とする帯電ローラである。帯電ローラ２１０は、感光体２０９表面に押圧力を持って当接され、感光体２０９の回転に伴い従動回転する（帯電ローラ２１０は、矢印Ａ方向に回転する）。
【０２３６】
帯電ローラを用いたときの好ましいプロセス条件としては、ローラの当接圧が５〜５００ｇ／ｃｍであり、印加バイアスとしては直流バイアスあるいは直流バイアスに交流バイアスを重畳したものが用いられ、特に限定されないが、本発明においては直流バイアスのみの印加バイアスが好適に用いられ、この場合のバイアス値としては、絶対値で０．２〜５．０ｋＶの範囲で使用される。
【０２３７】
本発明の画像形成装置においては、種々の帯電方法を使用することができるが、上述したように、帯電部材と静電潜像担持体を接触させて、静電潜像担持体を帯電させる接触帯電法が好適に使用される。接触帯電法を用いる場合に、転写残トナーが多量に存在すると帯電部材に付着してしまい、結果、帯電不良を引き起こし、画像上に帯電ムラが発生することがある。即ち、接触帯電法により帯電を行う場合には、静電潜像担持体に接することのないコロナ放電等により帯電を行う場合に比べて、転写残トナー量をより少なく抑える必要がある。これらのことから、接触帯電法においては、平均円形度及び円形度標準偏差が厳密に規定された本発明のトナーを用いることが好ましい。
【０２３８】
この他の接触帯電法における帯電部材としては、帯電ブレードを用いる方法や、導電性ブラシを用いる方法がある。これらの接触帯電法における帯電は、非接触のコロナ帯電に比べて、高電圧を必要とせず、またオゾンの発生を抑制することができるため好ましい。接触帯電手段としての帯電ローラおよび帯電ブレードの材質としては、導電性ゴムが好ましく、その表面に離型性被膜を設けても良い。離型性被膜としては、ナイロン系樹脂、ＰＶＤＦ（ポリフッ化ビニリデン）、ＰＶＤＣ（ポリ塩化ビニリデン）が適用可能である。
【０２３９】
一次帯電工程に次いで、発光素子からの露光２１１によって感光体２０９上に情報信号に応じた静電潜像を形成し、トナー担持体２０２と当接する位置においてトナーにより静電潜像を現像しトナー像を形成する。さらに、本発明の画像形成方法は、デジタル潜像を現像するような場合に、好適な現像を行うことが可能となる。次に、上記トナー像は、転写装置２０６により転写材２０５上に転写される。このように本発明の画像形成方法において、感光体２０９と転写装置２０６は、転写材２０５を介して当接されていることが好ましい。
【０２４０】
更に転写材２０５上の転写トナー２１２は、加熱体としての加熱ローラ２０８と加圧部材としての加圧ローラ２０７とを有する定着装置を通過して、転写材に定着され、永久画像を得る。
【０２４１】
定着工程としては特に制限はないが、本発明においては、加熱定着装置を用いる定着工程が好ましく、さらには、上記のような加熱ローラと、それに対向圧接される加圧ローラとの間を通過させて加熱加圧定着する工程がより好ましい。
【０２４２】
上記加熱ローラとしては、内部にハロゲンヒータの如き発熱体を内蔵したものが挙げられ、上記加圧ローラは、弾性体からなるものが挙げられる。
【０２４３】
なお、加熱加圧定着手段としては、加熱ローラと加圧ローラを基本構成とする上記のような熱ローラ方式以外に、フィルムを介してヒーターにより加熱定着する方式も、本発明のトナーを良好なマッチングを示すことから用いることができる。この様な方式として具体的には、図３、図４に示されるが、フィルム端部規制フランジ２５は、定着フィルム２２の左右両端部を支持している。筒状の定着フィルム２２内にステー２０が配置され、給電コネクタ２６および断電部材２７と一体となって、加熱体２１を装備して定着加熱部を構成する。フィルム端部規制フランジ２５は、コイルばね２４をばね受け部材（不図示）との間に縮設することによりステー２０に押し下げ力を作用させている。これにより定着フィルム２２の下面と加圧ローラ２３の上面とで所定幅の定着ニップ部が形成される。加熱体２１は、ヒーター基板２１ａと発熱体２１ｂと表面保護層２１ｃと検温素子２１ｄからなる。加圧ローラ２３はシリコーンゴム等の発泡体を下層に有するスポンジ加圧ローラである。定着フィルム２２には、転写材との接触面に耐熱性フィルムを使用することが好ましい。耐熱性フィルムとしては、具体的にＰＴＦＥの如き樹脂に導電物質を分散させた、低抵抗の離型層を有する厚さのものを使用することができる。
【０２４４】
例えば、加熱体２１の検温素子２１ｄの表面温度を１８０℃となるようにし、加熱体２１とシリコーンゴムの発泡体を下層に有するスポンジ加圧ローラ２３との間の総圧を６ｋｇ、加圧ローラ２３と定着フィルム２２のニップを８ｍｍとする。定着フィルム２２には、転写材との接触面にＰＴＦＥ（高分子量タイプ）に導電性物質を分散させた低抵抗の離型層を有する厚さ６０μｍの耐熱性ポリイミドフィルムを使用することができる。
【０２４５】
一方、転写されずに感光体２０９上に残った転写残トナー２１３は、感光体２０９と帯電ローラ２１０の間を通過して、再び現像当接部に到達し、現像兼クリーニング工程によりトナー担持体２０２を介して現像器２００内に回収される。このように転写後の感光体上の転写残トナーは、現像兼クリーニング工程により回収されるが、このとき回収されたトナーは、現像器に回収され、再度現像に使用される。
【０２４６】
また、本発明の画像形成方法は、中間転写方式を用いたフルカラーでの画像形成方法でも良く、上記した接触現像方式を好適に使用することができる。
【０２４７】
図２は、中間転写体として中間転写ベルトを用いたカラー画像形成装置（複写機あるいはレーザビームプリンタ）の一例である。本発明の画像形成方法において用いるトナーは、上記した本発明のトナーとする。また、中間転写ベルトを用いる以外は、上記の画像形成装置と同様のものを用いた他の画像形成方法を利用できる。
【０２４８】
第１の静電潜像担持体としてのドラム状の電子写真感光体である感光ドラム１０１は、矢印のＸ方向に所定の周速度（プロセススピード）で回転駆動される。感光ドラム１０１は回転過程で、１次帯電器１０２により所定の極性電位に一様に帯電処理され、次いで像露光手段（不示図）による露光１０３を受ける。このようにして目的のカラー画像の第１の色成分像（例えばイエロー色成分像）に対応した静電潜像が形成される。
【０２４９】
次いで、その静電潜像が第１の現像器（イエロー色現像器１４１）により第１色であるイエロー成分像に現像される。このとき第２?第４の現像器、即ち、マゼンタ現像器１４２、シアン色現像器１４３及びブラック色現像器１４４は作動しておらず、感光ドラム１０１には作用していないので、上記第１色のイエロー成分画像は上記第２〜第４の現像器による影響を受けない。
【０２５０】
中間転写ベルト１２０は矢印Ｗの方向に感光ドラム１０１と同じ周速度で回転駆動される。
【０２５１】
感光ドラム１０１上に形成された上記第１色のイエロー成分像が、感光ドラム１０１と中間転写ベルト１２０との当接部を通過する過程で、１次転写ローラ１６２を介してバイアス電源１２９から中間転写ベルト１２０に印加される１次転写バイアスによって形成される電界により、中間転写ベルト１２０の外周面に転写（１次転写）されていく。
【０２５２】
中間転写ベルト１２０に対応する第１色のイエロートナー像の転写を終えた感光ドラム１０１の表面は、クリーニング装置１１３によりクリーニングされる。
【０２５３】
以下、同様に第２色のマゼンタトナー像、第３色のシアントナー像、第４色のブラックトナー像を形成し、順次中間転写ベルト１２０上に重ね合わせて転写され、目的のカラー画像に対応した合成カラートナー像が形成される。
【０２５４】
２次転写ローラ１６３は、２次転写対向ローラ１６４に対応し平行に軸受させて中間転写ベルト１２０の下面部に離間可能な状態に配設してある。
【０２５５】
トナー像を感光ドラム１０１から中間転写ベルト１２０へ転写するための１次転写バイアスは、トナーとは逆極性でバイアス電源１２９から印加される。その印加電圧は例えば、＋１００Ｖ〜＋２ｋＶの範囲である。
【０２５６】
感光ドラム１０１から中間転写ベルト１２０へ第１色〜第３色のトナー像を１次転写する際には、中間転写ベルト１２０から２次転写ローラ１６３を離間することも可能である。図２の（ｂ）の如く、転写残トナー帯電部材１５２を有するような場合には、これも中間転写ベルト１２０から離間する。尚、転写残トナー帯電部材には、バイアス電源１２６より電圧が印加されている。
【０２５７】
ガイド１１０を通って、給紙ローラ１１１から中間転写ベルト１２０と２次転写ローラ１６３との当接部分に所定のタイミングで第２の画像担持体である転写材Ｐが給送される。２次転写バイアスが、バイアス電源１２８によって２次転写ローラ１６３に印加されることにより、中間転写ベルト１２０上に転写されたフルカラー画像は、転写材Ｐに２次転写される。トナー像が転写された転写材Ｐは、定着器１１５へ導入され加熱定着される。
【０２５８】
転写材Ｐへの画像転写終了後、中間転写ベルト１２０には転写残トナークリーニング装置１５０が当接され、中間転写ベルト１２０の表面が清掃される。
【０２５９】
また、中間転写体として、中間転写ベルトに変えて中間転写ドラムも同様に使用することが出来る。その一例について、以下に述べる。
【０２６０】
中間転写ドラムは、パイプ状の導電性芯金と、その外周面に形成した中抵抗の弾性体層からなる。芯金は、プラスチックのパイプに導電性メッキを施したものでも良い。
【０２６１】
中抵抗の弾性体層としては、シリコーンゴム、テフロンゴム、クロロプレンゴム、ウレタンゴム、ＥＰＤＭ（エチレン−プロピレン−ジエンの三元共重合体）の如き弾性材料に、カーボンブラック、酸化亜鉛、酸化錫、炭化珪素の如き導電性付与剤を配合分散して電気抵抗値（体積抵抗）を１０⁵〜１０¹¹Ω・ｃｍ程度の中抵抗に調整した、ソリッドあるいは発泡肉質の層が好適に用いられる。
【０２６２】
中間転写ドラムは、静電潜像担持体に対して並行に軸受けさせて静電潜像担持体の下面部に接触して配設されており、静電潜像担持体と同じ周速度で静電潜像担持体と同方向または逆方向に回転する。
【０２６３】
中間転写ドラムに対して並行に軸受けさせて中間転写ドラムの下面部に接触させて転写装置が配設され、転写装置は例えば転写ローラまたは転写ベルトであり、中間転写ドラムと同じ周速度で接触部において同方向に回転する。
【０２６４】
転写装置は直接中間転写ドラムと接触するように配設されていて、転写ローラの場合、中心の芯金とその外周を形成した導電性弾性層とを基本構成とするものである。
【０２６５】
中間転写ドラムおよび転写ローラとしては、一般的な材料を用いることが可能である。中間転写ドラムの弾性層の体積固有抵抗値をより小さく設定することで転写ローラへの印加電圧が軽減でき、転写材上に良好なトナー像を形成できると共に転写材の中間転写ドラムへの巻き付きを防止することができる。特に中間転写ドラムの弾性層の体積抵抗値が、転写ローラの弾性層の体積抵抗値の１０倍以上であることが特に好ましい。
【０２６６】
例えば、転写ローラの導電性弾性層はカーボンの如き導電材を分散させたポリウレタン、エチレン−プロピレン−ジエン系三元共重合体（ＥＰＤＭ）の如き体積抵抗値１０⁶〜１０¹⁰Ω・ｃｍ程度の弾性体でつくられる。転写ローラの芯金には低電圧電源によりバイアスが印加されており、バイアス条件としては、絶対値で０．２〜１０ｋＶが好ましい。
【０２６７】
なお、上記において、現像兼クリーニング工程を有する一成分現像法による画像形成方法、又は中間転写ベルトおよび中間転写ドラムを有する画像形成装置を用いた中間転写方式の画像形成方法について説明したが、本願発明のトナーは、上記以外の画像形成方法においても好適に用いることができる。
【０２６８】
【実施例】
以下、本発明を実施例により具体的に説明するが、本発明はこれらに何ら限定されるものではない。
【０２６９】
以下の配合における部数は全て質量部である。
【０２７０】
＜１＞ジエン単量体成分含有樹脂の製造
以下のようにジエン単量体成分含有樹脂１〜１０までを製造した。
【０２７１】
＜ジエン単量体成分含有樹脂１の製造＞
減圧可能な反応容器に、スチレン８０質量部と2,2'-アゾビスイソブチロニトリル1質量部及びベンゼン５００質量部を加え、これに２０質量部の1,3-ブタジエンを液化計量器を通して蒸留により仕込み、次いで溶存空気の泡がなくなるまで減圧脱気を繰り返し、真空下に溶封した。これを６０℃の恒温槽中で振とうしながら、重合させた。重合終了後、封管を開け内容物をメタノール中に投じ再沈殿させた。上澄みをデカンテーションし、沈殿物をメタノールにて洗浄した後に、４０℃、２００Ｐａ（１．５ｍｍＨｇ）で２４時間減圧乾燥してスチレンブタジエン共重合体（ジエン単量体成分含有樹脂１）を得た。この重合体の組成比は、以下のようにして求めた。その結果、スチレン／ブタジエンの質量比は、８０／２０であった。原料の混合比率を表２に示し、特性値を表３に示す。
【０２７２】
ジエン単量体に由来する成分の含有量の測定は、¹Ｈ−ＮＭＲを用いて以下のようにして行った。
【０２７３】
十分に洗浄及び乾燥した重合体５０〜１００ｍｇを秤量し、１体積％テトラメチルシランを含有した重水素化溶媒１．０ｍｌに一昼夜溶解し、必要に応じてメンブランフィルターで不溶分を除いた後、直径１０ｍｍのサンプルチューブに入れ、ＦＴ−ＮＭＲ装置 ＪＮＭ−ＥＸ４００（日本電子社製）を用いて測定した。
【０２７４】
【表２】

【０２７５】
【表３】

＜ジエン単量体成分含有樹脂２の製造＞
使用した単量体の種類及び量を表２に示すとおりに変える以外は、ジエン単量体成分含有樹脂１の製造と同様にしてジエン単量体成分含有樹脂２を得た。その特性値を表３に示す。
【０２７６】
＜ジエン単量体成分含有樹脂３の製造＞
セプタムキャップを装備した耐圧ビンに水１２６質量部、不均化ロジン酸カリウム３．３質量部、ナフタレンスルホン酸−ホルマリン縮合物のナトリウム塩０．０７質量部、テトラエチレンペンタミン０．０７質量部、スチレン５０質量部、第三ドデシルメルカプタン０．１７質量部を仕込み、さらに液化計量器を使用してイソプレン９質量部を仕込み、イソプレンを２質量部気化させて内部の空気を追い出して栓をした。５℃の回転式重合相の回転板に取り付け３０分間攪拌後、注射器を用いてクメンヒドロペルオキシド０．１質量部とスチレン３．５質量部の溶液を注入し重合を開始した。７２時間後にジメチルジチオカルバミン酸ナトリウム１０％水溶液３．５質量部を注入して重合を停止させ、スチームを吹き込んで未反応モノマーを追い出した。共重合体の２％に相当するフェニル−６−ナフチルアミンを添加後、２５％食塩水、続いて１％硫酸を注いで共重合体を凝固させ水洗後、乾燥させてジエン単量体成分含有樹脂３を得た。その特性値を表３に示す。
【０２７７】
＜ジエン単量体成分含有樹脂４の製造＞
使用した単量体の種類及び量を表２に示すとおりに変える以外は、ジエン単量体成分含有樹脂３の製造と同様にしてジエン単量体成分含有樹脂４を得た。その特性値を表３に示す。
【０２７８】
＜ジエン単量体成分含有樹脂５の製造＞
スチレン８５質量部、ブタジエン１５質量部、脂肪酸ナトリウム５質量部、イオン交換水２００質量部を混合し、重合器であるオートクレーブ中に入れた。次いでｎ−ドデシルメルカプタン３．５質量部、過硫酸カリウム０．２質量部を加え、５０度で１５時間乳化重合させ、ジエン単量体成分含有樹脂５を得た。その特性値を表３に示す。
【０２７９】
＜ジエン単量体成分含有樹脂６の製造＞
３０ｌオートクレーブにベンジルナトリウム１１４質量部、トルエン３６８質量部、ｎ−ヘキサン９９００質量部を窒素気流下で仕込み、３０℃にした後、ブタジエン８１８５質量部を３０℃に保ちながら２時間かけて滴下後、メタノール２００質量部を加え重合を停止した。次に白土１０００質量部を加え激しく攪拌した後、ろ過しアルカリを含まない透明なポリマー溶液を得た。次にこのポリマー溶液から未反応ブタジエン、トルエン、ｎ−ヘキサンを留去し、数平均分子量１９００のジエン単量体成分含有樹脂６を合成した。その特性値を表４に示す。
【０２８０】
【表４】

＜ジエン単量体成分含有樹脂７の製造＞
ジエン単量体成分含有樹脂６を１０００質量部、無水マレイン酸１５０質量部、キシレン３００質量部、アンチゲン３Ｃ（住友化学商品名）２質量部を２ｌオートクレープに仕込み窒素気流下に１９０℃で８時間反応させた。次に未反応無水マレイン酸、キシレンを減圧下で留去し、数平均分子量２０００のマレイン化ポリブタジエン（ジエン単量体成分含有樹脂７）を合成した。
【０２８１】
マレイン化ポリブタジエン(A)’中の酸基の構造は、大部分が下記（IV）で示されるものである。
【０２８２】
【外１０】

【０２８３】
また、一部空気中や溶媒などに含まれる水により加水分解した下記式（V）の構造のものも含まれている。
【０２８４】
【外１１】

【０２８５】
ジエン単量体成分含有樹脂７の特性値を表４に示す。
【０２８６】
＜ジエン単量体成分含有樹脂８の製造＞
ジエン単量体成分含有樹脂６の製造例で、使用した原材料のブタジエンをイソプレン６５００質量部に変える以外はジエン単量体成分含有樹脂６の製造と同様にしてジエン単量体成分含有樹脂８を得た。その特性値を表４に示す。
【０２８７】
＜ジエン単量体成分含有樹脂９の製造＞
コンデンサー、過酢酸仕込み口、Ｎ₂導入管を備えたジャケット付き２ｌ反応器にジエン単量体成分含有樹脂８の固形分４６．３％の酢酸エチル溶液４００質量部を仕込んだ。次に過酢酸２８０質量部（３０％、酢酸エチル溶液）に２−エチルへキシルトリポリリン酸ナトリウム０．２質量部を加え溶解させた。その後５０℃に反応温度を保持しながら約４時間で過酢酸溶液を滴下した。その後５０℃でさらに６時間保った。
【０２８８】
次いで、６８０質量部の精製水を加え３０分攪拌後５０℃で静置した。３０分後、分液した水相を徐々に抜き取った。次に酢酸エチル３００質量部を加え、さらに精製水８００質量部を加え３０分攪拌した後、５０℃に維持しながら３０分静置して水相を抜き取った。さらに精製水７００質量部を加え５０℃で３０分攪拌した。次いで５０℃で３０分間静置し、水相を抜き取り、固形分３０．１％の酢酸エチル溶液６５０質量部を得た。
【０２８９】
続いて、得られた上層液を薄膜式蒸発器に５０℃、２７００〜６７００Ｐａ（２０〜５０ｍｍＨｇ）及び３００ｍｌ／ｈという条件で仕込んで、目的のエポキシ基を有するジエン単量体成分含有樹脂９を１８０質量部得た。その特性値を表４に示す。
【０２９０】
＜ジエン単量体成分含有樹脂１０の製造＞
コンデンサー、Ｎ₂導入管を備えたジャケット付き２ｌ反応器に、合成したジエン単量体成分含有樹脂７の１１５０質量部にグリシジルメタクリレート１５０質量部を加えて、反応容器中で６０℃に加熱して１２時間反応させて、ジエン単量体成分含有樹脂１０を１３００質量部得た。その特性値を表４に示す。
【０２９１】
＜２＞ジエン単量体成分含有樹脂と併用する樹脂の製造
以下のように樹脂１及び２を製造した。
【０２９２】
＜樹脂１の製造＞
温度計、ステンレス攪拌棒、流下式コンデンサーおよび窒素導入管を装備したガラス製のセパラブルフラスコに、キシレン２００質量部を入れ還流温度まで昇温した。これにスチレン８０質量部、アクリル酸−ｎ−ブチル２０質量部およびジ−ｔｅｒｔ−ブチルパーオキサイド２．３質量部の混合液を滴下後、キシレン還流下、７時間で溶液重合を完了し、低分子量樹脂溶液を得た。
【０２９３】
一方、スチレン６５質量部、アクリル酸ブチル２５部、マレイン酸モノブチル１０質量部、ポリビニルアルコール０．２質量部、脱気水２００質量部、過酸化ベンゾイル０．５質量部を混合懸濁分散させた。上記懸濁分散溶液を加熱し、窒素雰囲気下において８５℃に２４時間保持して重合を完結させ、高分子量樹脂を得た。
【０２９４】
上記高分子量樹脂３０質量部を前記の低分子量樹脂７０質量部を含有する低分子量樹脂溶液中に投入し、溶媒中に完全に溶解せしめ混合を行い、その後、溶媒を留去して樹脂１を得た。
【０２９５】
上記樹脂１を分析したところ、低分子量側ピーク分子量は１万、高分子量側ピーク分子量は５６万、重量平均分子量（Ｍｗ）は３０万、数平均分子量（Ｍｎ）は５．５万であった。また、ガラス転移温度は５５℃であった。
【０２９６】
＜樹脂２の製造＞
樹脂１の製造の場合と同様にして、低分子量樹脂溶液を得た。
【０２９７】
一方、スチレン７５質量部、アクリル酸ブチル２５部、ポリビニルアルコール０．２質量部、脱気水２００質量部、過酸化ベンゾイル０．５質量部を混合懸濁分散させた。上記懸濁分散溶液を加熱し、窒素雰囲気下において８５℃に２４時間保持して重合を完結させ、高分子量樹脂を得た。
【０２９８】
上記高分子量樹脂３０質量部を前記の低分子量樹脂７０質量部を含有する低分子量樹脂溶液中に投入し、溶媒中に完全に溶解せしめ混合を行い、その後、溶媒を留去して樹脂２を得た。
【０２９９】
上記樹脂２を分析したところ、低分子量側ピーク分子量は１．２万、高分子量側ピーク分子量は５８万、重量平均分子量（Ｍｗ）は３０万、数平均分子量（Ｍｎ）は５．５万であった。また、ガラス転移温度は５５℃であった。
【０３００】
＜３＞トナーの製造
以下のように、本発明のトナー１〜１２及び比較用のトナーとして比較用トナー１〜６を製造した。
【０３０１】
＜トナー１の製造＞
・樹脂１ １００質量部
・ジエン単量体成分含有樹脂１ １０質量部
・カーボンブラック（ＢＥＴ比表面積＝９０ｍ²／ｇ） １０質量部
・負荷電性制御剤（前記化合物（II）） ２質量部
・低分子量ポリエチレン（吸熱ピークの極大値＝１１５℃） ５質量部
上記材料をブレンダーにて混合し、これを１６０℃に加熱した二軸エクストルーダーで溶融混練し、冷却した混練物をハンマーミルで粗粉砕した後、粗粉砕物をジェットミルで微粉砕した。
【０３０２】
次いで、ローターを回転して機械的衝撃量を与える装置を用いて、表面改質処理を行い、得られた粒子を分級して分級粉１とした。一方、高速攪拌装置ＴＫ式ホモミキサー（特殊機化工業社製）を備えた２ｌの４つ口フラスコ中にイオン交換水６５０質量部と０．１ｍｏｌ／ｌ−Ｎａ₃ＰＯ₄水溶液５００質量部を投入し、回転数を１２０００ｒｐｍに調整し、７０℃に加温せしめた。ここに１．０ｍｏｌ／ｌ−ＣａＣｌ₂水溶液８０質量部を添加し、微小な難水溶性分散安定剤（リン酸カルシウム塩）を含む水系分散媒体を調製した。分散安定剤を含有する水系分散媒体へ上記分級粉１の１２７質量部を徐々に投入し、６０℃に加温して同温度を保持し、そこへｔ−ブチルパーオキシネオデカノエート０．７質量部をドデシルベンゼンスルホン酸ナトリウム０．０１質量部とイオン交換水２０質量部に超音波分散せしめた分散液を５分間かけて添加し、その後同温度で５時間保持して反応を行った。反応終了後、懸濁液を冷却し、次いで希塩酸を添加し分散安定剤を除去せしめた。さらに水洗浄を数回繰り返した後、乾燥させ、反応処理粒子Ａを得た。
【０３０３】
上記反応処理粒子Ａの１００質量部とシリコーンオイルで処理された疎水性シリカ微粉体(ＢＥＴ比表面積２４０ｍ²／ｇ)１．２質量部をヘンシェルミキサーで乾式混合して、本発明のトナー１とした。
【０３０４】
トナー１の平均円形度は０．９５３、円形度標準偏差は０．０３９、円相当個数平均径Ｄ１は５．３μｍ、高分子量側ピーク分子量は５８万、低分子量側ピーク分子量は１．１万であった。
【０３０５】
＜トナー２の製造＞
結着樹脂の種類、および添加量を変える以外はトナー１の製造と同様にしてトナー２を得た。使用した材料の種類と量を表５に、トナーの分析結果を表８に示す。
【０３０６】
【表５】

【０３０７】
＜トナー３の製造＞
高速攪拌装置TK式ホモミキサー(特殊機化工業社製)を備えた２ｌの４つ口フラスコ中にイオン交換水６５０質量部と０．１ｍｏｌ／ｌ−Ｎａ₃ＰＯ₄水溶液５００質量部を投入し、回転数を１２０００ｒｐｍに調整し、７０℃に加温せしめた。ここに１．０ｍｏｌ／ｌ−ＣａＣｌ₂水溶液８０質量部を添加し、微小な難水溶性分散安定剤（リン酸カルシウム塩）を含む水系分散媒体を調製した。
【０３０８】
一方、分散質として、
・スチレン ８２質量部
・２−エチルへキシルアクリレート １８質量部
・カーボンブラック（ＢＥＴ比表面積＝９０ｍ²／ｇ） １０質量部
・ジエン単量体成分含有樹脂１ １０質量部
・ワックス（エステルワックス、吸熱ピークの極大値＝７６℃） ７質量部
・負荷電性制御剤（化合物（II）） ２質量部
上記混合物をアトライター（三井金属社製）を用い３時間分散させた後、2,2'-アゾビス（2,4-ジメチルバレロニトリル）３質量部を添加し重合性単量体組成物を調製した。
【０３０９】
次に、前記水系分散媒体中に上記重合性単量体組成物を投入し、内温７０度の窒素雰囲気下で、高速攪拌機の回転数を１２０００ｒｐｍに維持しつつ、１０分間攪拌し、上記重合性単量体組成物を造粒した。その後、攪拌器をプロペラ攪拌羽根に換え５０ｒｐｍで攪拌しながら同温度で２時間保持した時点で、過硫酸カリウム０．４質量部をイオン交換水２０質量部に溶解せしめた溶液を５分間かけて添加し、さらに同温度で８時間保持して重合を完了した。過硫酸カリウムを添加した時点での重合反応の転化率は、４３％であった。
【０３１０】
重合終了後、懸濁液を冷却し、次いで希塩酸を添加し分散安定剤を除去せしめた。さらに水洗浄を数回繰り返した後、乾燥させ、重合体粒子３を得た。上記重合体粒子３は、質量平均径が６．８μmであった。
【０３１１】
上記重合体粒子３の１００質量部とシリコーンオイルで処理された疎水性シリカ微粉体（ＢＥＴ比表面積２４０ｍ²／ｇ）１．５質量部をヘンシェルミキサーで乾式混合して本発明のトナー３とした。
【０３１２】
トナー３の平均円形度は０．９８９、円形度標準偏差は０．０２１、円相当個数平均径Ｄ１は５．５μm、ピーク分子量は２．６万であった。
【０３１３】
＜トナー４〜１０の製造＞
結着樹脂の種類、添加量及び反応処理時の反応温度を変える以外はトナー３の製造と同様にしてトナー４〜１０を得た。使用した材料の種類と量を表６に、トナーの分析結果を表８に示す。
【０３１４】
【表６】

【０３１５】
＜トナー１１及び１２の製造＞
結着樹脂の種類、添加量及び反応処理時の反応温度を変えて、表６に示す重合転化率のときに表中の有機過酸化物をドデシルベンゼンスルホン酸ナトリウム０．０１質量部とイオン交換水に超音波分散せしめた分散液を５分間かけて添加した以外は、トナー３の製造と同様にしてトナー１１及び１２を得た。使用した材料の種類と量を表６に、トナーの分析結果を表８に示す。
【０３１６】
＜比較用トナー１の製造＞
原材料の種類、添加量を変える以外はトナー１の製造と同様にして比較用トナー１を得た。使用した材料の種類と量を表５に、トナーの分析結果を表８に示す。
【０３１７】
＜比較用トナー２の製造＞
原材料の種類、添加量を変え、開始剤による反応処理を行わない以外はトナー１の製造と同様にして比較用トナー２を得た。使用した材料の種類と量を表５に、トナーの分析結果を表８に示す。
【０３１８】
＜比較用トナー３〜６製造＞
結着樹脂の種類、および添加量を変える以外はトナー３と同様にして比較用トナー３〜６を得た。使用した材料の種類と量を表７に、トナーの分析結果を表８に示す。
【０３１９】
＜比較用トナー７製造＞
高速攪拌装置TK式ホモミキサー(特殊機化工業社製)を備えた２ｌの４つ口フラスコ中にイオン交換水６５０質量部と０．１ｍｏｌ／ｌ−Ｎａ₃ＰＯ₄水溶液５００質量部を投入し、回転数を１２０００ｒｐｍに調整し、７０℃に加温せしめた。ここに１．０ｍｏｌ／ｌ−ＣａＣｌ₂水溶液８０質量部を添加し、微小な難水溶性分散安定剤（リン酸カルシウム塩）を含む水系分散媒体を調製した。
【０３２０】
一方、分散質として、
・スチレン ８２質量部
・２−エチルへキシルアクリレート １８質量部
・カーボンブラック（ＢＥＴ比表面積＝９０ｍ²／ｇ） １０質量部
・不飽和ポリエステル １０質量部
・ワックス（エステルワックス、吸熱ピークの極大値＝７６℃） ７質量部
・負荷電性制御剤（化合物（II）） ２質量部
上記混合物をアトライター（三井金属社製）を用い３時間分散させた後、2,2'-アゾビス（2,4-ジメチルバレロニトリル）３質量部を添加し重合性単量体組成物を調製した。
【０３２１】
次に、前記水系分散媒体中に上記重合性単量体組成物を投入し、内温７０度の窒素雰囲気下で、高速攪拌機の回転数を１２０００ｒｐｍに維持しつつ、１０分間攪拌し、上記重合性単量体組成物を造粒した。その後、攪拌器をプロペラ攪拌羽根に換え５０ｒｐｍで攪拌しながら同温度で２時間保持した時点で、スチレンモノマー８．２質量部、n-ブチルアクリレート１．８質量部、不飽和ポリエステル２．５質量部、過硫酸カリウム０．４質量部をイオン交換水４０質量部に溶解・分散せしめた重合性単量体組成物を６０分間かけて添加し、さらに同温度で８時間保持して重合を完了した。重合性単量体組成物を添加した時点での重合反応の転化率は、６０％であった。
【０３２２】
重合終了後、懸濁液を冷却し、次いで希塩酸を添加し分散安定剤を除去せしめた。さらに水洗浄を数回繰り返した後、乾燥させ、重合体粒子７を得た。上記比較用重合体粒子７は、質量平均径が７．０μmであった。
【０３２３】
上記重合体粒子７の１００質量部とシリコーンオイルで処理された疎水性シリカ微粉体（ＢＥＴ比表面積２４０ｍ²／ｇ）１．５質量部をヘンシェルミキサーで乾式混合して比較用トナー７とした。
【０３２４】
比較用トナー７の平均円形度は０．９７５、円形度標準偏差は０．０３１、円相当個数平均径Ｄ１は５．８μm、ピーク分子量は３．０万であった。トナーの分析結果を表８に示す。
【０３２５】
【表７】

【０３２６】
【表８】

【０３２７】
＜実施例１＞
上記の如くして得られた本発明のトナー１〜１２、及び比較用トナー１〜７を以下のようにして評価した。
【０３２８】
まず、本実施例に用いた画像形成装置について説明する。本実施例中では、市販のレーザービームプリンターＬＢＰ−ＰＸ（キヤノン製）を非磁性一成分現像用に改造して用いた。図１を参照しながら、本画像形成装置について説明する。
【０３２９】
本実施例では、感光体上のネガ（負極性）潜像をネガ（負極性）トナーを用いて現像する反転現像の装置を利用した。
【０３３０】
図１は本発明に適用するレーザービームプリンターの断面の概略的説明図である。ＯＰＣ感光ドラム１０（直径２４ｍｍ）は、矢印の方向に回転し、帯電ロール１１により暗部電位（Ｖｄ）が−６００Ｖになるように均一に帯電される。次に露光装置１４により、画像部に露光が行われ、明部電位（Ｖｌ）が−１５０Ｖの静電潜像が形成される。トナー塗布ローラ１６を有するトナー担持体１７上のトナー層と感光ドラム１０とを接触させずに３００μｍの間隔をもって設定し、交流バイアス（ｆ＝１８００Ｈｚ、Ｖｐｐ＝１４００Ｖ）、及び直流バイアス（Ｖｄｃ＝−４００Ｖ）とをバイアス印加手段Ｖによりトナー担持体１７に印加しながら、画像部をネガトナーＴで現像してトナー像を感光ドラム１０上に形成した。
【０３３１】
得られた上記トナー像を転写ロール１９によって転写材Ｐ上にトナーを転写し、感光ドラム１０の表面上に残ったトナーをクリーナー１３によりクリーニングする。一方、感光ドラム１０から分離された転写材Ｐは、転写材Ｐ上のトナー像を定着するために加熱定着装置Ｈにより加熱定着処理される。以上の工程を繰り返して画像形成を行っている。このとき加熱定着装置Ｈとしては、図３及び４に記載されているものを用い、加熱体２１の検温素子２１ｄの表面温度は１９０℃、加熱体２１と加圧ローラ２３間の総圧は６ｋｇ、加圧ローラ２３と定着フィルム２２のニップは３ｍｍとし、定着フィルム２２には、転写材との接触面にＰＴＦＥに導電物質を分散させた低抵抗の離型層を有する厚さ５０μｍの耐熱性ポリイミドフィルムを使用した。
【０３３２】
また、ここで用いたトナー担持体の表面粗度Ｒａ（μm）は１．５であり、トナー層厚規制ブレードの材質はステンレスである。
【０３３３】
本実施例においては、上記の図１に示す画像形成装置を用い、常温常湿（２５℃、６０％ＲＨ）、高温高湿（３０℃、８０％ＲＨ）及び低温低湿（１５℃、１０％ＲＨ）環境下で、２８枚／分(Ａ４サイズ)のプリントアウト速度で、本発明のトナー１〜１２及び比較用トナー１〜６を間欠モード（すなわち、１枚プリントアウトする毎に１０秒間現像器を休止させ、再起動時の予備動作でトナーの劣化を促進させるモード）で５０００枚のプリントアウト試験を行った。そして、得られたプリントアウト画像を後述の項目について評価した。
【０３３４】
＜プリントアウト画像評価＞
【０３３５】
（１）画像濃度
通常の複写機用普通紙（７５ｇ／ｍ²）を用いた５０００枚のプリントアウト試験終了時の画像濃度により評価した。尚、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。
Ａ：１．４０以上
Ｂ：１．３５以上、１．４０未満
Ｃ：１．００以上、１．３５未満
Ｄ：１．００未満
【０３３６】
（２）画像カブリ
「リフレクトメータ MODEL TC-6DS」（東京電色社製）を用いて、プリントアウト試験終了時のプリントアウト画像の白地部分の白色度と転写紙の白色度の差からカブリ濃度(％)を算出し、画像カブリを評価した。フィルターは、グリーンフィルターを用いた。数値が小さい程、カブリが少ないことを意味する。
Ａ：１．５％未満
Ｂ：１．５％以上、２．５％未満
Ｃ：２．５％以上、４．０％未満
Ｄ：４．０％以上
【０３３７】
（３）ハーフトーン画像の均一性
プリントアウト試験終了時のプリントアウト画像の画質を以下の基準で評価した。
Ａ：非常に良好。
Ｂ：わずかにがさついているものの、良好な画像。
Ｃ：がさついているものの、実用上問題の無いレベル。
Ｄ：ひどいがさつきが生じた。
【０３３８】
（４）定着性
定着性は５０ｇ／ｃｍ²の荷重をかけ、柔和な薄紙により定着画像を５往復摺擦し、摺擦前後での画像濃度の低下率（％）で評価した。
Ａ：５％未満
Ｂ：５％以上、１０％未満
Ｃ：１０％以上、２０％未満
Ｄ：２０％以上
【０３３９】
（５）耐オフセット性
耐オフセット性は、画像面積率約５％のサンプル画像をプリントアウトし、５０００枚後の画像上の汚れの程度により評価した。
A：汚れは未発生。
B：かすかに汚れが見られる。
C：若干の汚れが見られる。
D：顕著な汚れが発生する。
【０３４０】
これらの評価結果を表９に示す。
【０３４１】
【表９】

【０３４２】
＜実施例２＞
前述のトナーの製造例で得られた本発明のトナー３〜１２、及び比較用トナー３〜７を以下のようにして評価した。
【０３４３】
まず、画像形成装置として、上記実施の形態の図５で示される画像形成装置と同様の構造を有する装置を実施例２の画像形成装置とした。具体的には、以下の通りである。
【０３４４】
６００ｄｐｉレーザービームプリンター（キヤノン製：ＬＢＰ−８６０）を用意し、プロセススピードを６０ｍｍ／ｓに改造した。
【０３４５】
このプロセスカートリッジにおけるクリーニングゴムブレードを取り外し、装置の帯電方式を、ゴムローラを静電潜像担持体（感光体）に当接して行う直接帯電とし、印加電圧を直流成分（−１２００Ｖ）とした。次にプロセスカートリッジにおける現像部分を改造した。ステンレススリーブの代わりにカーボンブラックを分散したシリコーンゴムからなる中抵抗ゴムローラ（直径１６ｍｍ、硬度ASKER C ４５度、抵抗１０⁵Ω・ｃｍ）をトナー担持体とし、感光体に当接した。この時の現像当接幅は約３ｍｍとなるようにした。上記トナー担持体の回転周速は、感光体との接触部分において同方向であり、上記感光体回転周速に対し１５０％となるように駆動させた。
【０３４６】
ここで用いる感光体としては、直径３０ｍｍ、２５４ｍｍのＡｌシリンダーを基体としたもので、これに、以下に示すような構成の層を順次浸漬塗布により積層して、感光体を作成した。
１）導電性被覆層：酸化錫及び酸化チタンの粉末をフェノール樹脂に分散したものを主体とする（膜厚１．５μｍ）。
２）下引き層：変性ナイロン、及び共重合ナイロンを主体とする（膜厚０．６μｍ）。
３）電荷発生層：長波長域に吸収を持つチタニルフタロシアニン顔料をブチラール樹脂に分散したものを主体とする（膜厚０．６μｍ）。
４）電荷輸送層：ホール搬送性トリフェニルアミン化合物をポリカーボネート樹脂（オストワルド粘度法による分子量２万）に８：１０の質量比で溶解したものを主体とする（膜厚２０μｍ）。
【０３４７】
トナー担持体にトナーを塗布する手段として、現像器内に発泡ウレタンゴムからなる塗布ローラを設け、上記トナー担持体に当接させた。塗布ローラには、約−５５０Ｖの電圧を印加する。さらに、上記トナー担持体上トナーのコート層制御のために樹脂をコートしたステンレス製ブレードを、トナー担持体との接触圧が線圧約２０ｇ／ｃｍとなるように取付けた。概略を図５に示す。また、現像時の印加電圧をDC成分（−４５０Ｖ）のみとした。
【０３４８】
これらのプロセスカートリッジの改造に適合するよう画像形成装置に以下のように改造及びプロセス条件設定を行った。
【０３４９】
改造された装置は、ローラ帯電器（直流のみを印加）を用い静電潜像担持体を一様に帯電する。帯電に次いで、レーザー光で画像部分を露光することにより静電潜像を形成し、トナーにより可視画像とした後に、電圧を印加したローラによりトナー像を転写材に転写するプロセスを持つ。
【０３５０】
また、感光体帯電電位は、暗部電位を−６００Ｖとし、明部電位を−１５０Ｖとした。転写材としては、７５ｇ／ｍ²の紙を用いた。
【０３５１】
上記画像形成装置により、本発明のトナー３〜１２及び比較用トナー３〜７を用いて、温度１５℃／湿度１０％の条件下で耐久試験を行った。
【０３５２】
なお、耐久性評価は印字面積比率３％で文字印刷を行い、以下のように評価した。
【０３５３】
（１）トナーの帯電ローラ汚染：ハーフトーン画像上に帯電部材汚染による帯電むらが発生した枚数で判断した。
Ａ：３０００枚まで発生せず
Ｂ：２７００枚から３０００枚未満の間で発生
Ｃ：２０００枚から２７００枚未満の間で発生
Ｄ：２０００枚未満で発生
【０３５４】
（２）トナーの感光体融着およびスリーブ融着：ベタ黒画像上に白抜けが発生した段階で感光体表面およびスリーブ表面を観察し、融着の有無を確認した。融着が観察されなければ耐久性評価を継続した。
Ａ：３０００枚まで発生せず
Ｂ：２７００枚から３０００枚未満の間で発生
Ｃ：２０００枚から２７００枚未満の間で発生
Ｄ：２０００枚未満で発生
帯電ローラ汚染、感光体融着およびスリーブ融着が発生しない場合３０００枚まで画像印刷を続けた。発生した枚数が多い程、トナーの耐久性が良好なことを意味する。
【０３５５】
（３）耐久初期の転写性：ベタ黒が像現像時の感光体上の転写残トナーをマイラーテープによりテーピングしてはぎ取り、紙上に貼ったもののマクベス濃度から、テープのみを貼ったもののマクベス濃度を差し引いた数値で評価した。従って、値の小さいほど転写性は良好である。
Ａ：０．０５未満
Ｂ：０．０５〜０．１０未満
Ｃ：０．１０〜０．２０未満
Ｄ：０．２０以上
【０３５６】
（４）耐久初期（１００枚時）の解像力は潜像電界によって電界が閉じやすく、再現しにくい図７に示すような小径（X=50μm）の孤立ドットパターンの画像をプリントアウトし、そのドット再現性を評価した。
Ａ：欠損２個以下／１００個
Ｂ：欠損３〜５個／１００個
Ｃ：欠損６〜１０個／１００個
Ｄ：欠損１１個以上／１００個
【０３５７】
（５）オフセット性：初期から耐久１００枚での画像サンプルの裏側に発生する汚れを観察し、発生枚数を数えた。
Ａ：未発生
Ｂ：発生枚数１〜２枚／１００枚
Ｃ：発生枚数３〜５枚／１００枚
Ｄ：発生枚数６枚以上／１００枚
【０３５８】
（６）カブリの測定：東京電色社製のREFLECTMETER MODEL TC-6DSを使用して測定した。フィルターは、グリーンフィルターを用い、測定したプリントアウト画像の白地部分の白色度と転写紙の白色度の差から、かぶり濃度（％）を算出し、画像カブリを評価した。数値が小さい程、カブリが少ない。
Ａ：１．５％未満
Ｂ：１．５％以上、２．５％未満
Ｃ：２．５％以上、４．０％未満
Ｄ：４．０％以上
これらの評価結果を表１０に示す。
【０３５９】
【表１０】

【０３６０】
＜実施例３＞
上記のトナーの製造例で得られた本発明のトナー５、及び比較用トナー６を以下のようにして評価した。
【０３６１】
まず、画像形成装置として、上記実施の形態の図２で示される画像形成装置と同様の構造を有する装置を用いた。
【０３６２】
具体的には、以下の通りである。
【０３６３】
トナー担持体面の移動速度が、静電潜像担持体面の移動速度に対し１５０％となるように設定し、常温常湿（２３℃、６５％ＲＨ）環境下で、２０枚／分（Ａ４サイズ）のプリントアウト速度でトナー５及び６’を単色での連続モード（すなわち、現像器を休止させることなくトナーの消費を促進させるモード）において印字面積比率５％で６０００枚のプリントアウト試験を行った。そして、得られたプリントアウト画像を前述の項目および中間転写ベルトへの汚染状態も含めて、評価した。
【０３６４】
（７）トナーの中間転写ベルト融着、感光体融着およびスリーブ融着：ベタ黒画像上に軽微な白抜けが発生した段階で中間転写ベルト、感光体表面およびスリーブ表面を観察し、融着の有無を確認した。融着が観察されなければ耐久性評価を継続した。
Ａ：６０００枚まで発生せず
Ｂ：５５００枚から６０００枚未満の間で発生
Ｃ：５０００枚から５５００枚未満の間で発生
Ｄ：５０００枚未満で発生
その結果を表１１に示す。
【０３６５】
【表１１】

【０３６６】
【発明の効果】
以上のように本発明の乾式トナーは、電子写真特性に優れ、高精細な画像を与え、帯電安定性に優れ、トナー担持体、静電潜像担持体、定着器等、中間転写体への汚染も少ないものである。さらに、本発明の乾式トナーの製造方法は、前記の優れた電子写真特性を有し、画像形成装置への汚染も少ないトナーを効率良く製造することが可能である。
【０３６７】
さらに、粒子表面近傍の強度を向上させたトナーを用いることにより、クリーナレス構成あるいは中間転写体を用いるような接触現像方式画像形成プロセスにおいて、定着性を維持しつつ、解像性、転写性を向上させ、トナーの回収性向上によるゴースト発生の抑制し、さらには耐久性をも大きく向上することができる。
【図面の簡単な説明】
【図１】本発明の画像形成方法を適用できる画像形成装置の１例の概略構成図を示す。
【図２】本発明の画像形成方法を実施するための中間転写ベルトを用いた画像形成装置の概略構成図を示す。
【図３】定着装置の要部の分解傾斜図を示す。
【図４】本発明の画像形成方法に適用できる定着装置の非駆動時のフィルム状態を示した要部の横断面図を示す。
【図５】一成分現像方式により画像形成を行う画像形成装置の概略構成図を示す。
【図６】本発明の画像形成方法に適用できる現像装置の概略構成図を示す。
【図７】トナーの現像特性をチェックするための小径孤立ドットパターンの図を示す。
【図８】ガラス転移温度の測定するためのグラフを表す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry toner used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method, and the like, and an image forming method using the toner. More specifically, the present invention relates to a toner used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter, and the like, and an image forming method using the toner.
[0002]
[Prior art]
As an electrophotographic technique, many methods are known as described in US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. In general, an electrostatic charge latent image is formed on a photoreceptor using a photoconductive substance by various means, and then the electrostatic charge latent image is developed using a dry toner (hereinafter also referred to as “toner”). Accordingly, the toner image is transferred to a transfer material such as paper or film, and then fixed by heating, pressure, heating and pressing, or solvent vapor to obtain a toner image.
[0003]
As a method for visualizing an electrostatic latent image, a cascade development method, a magnetic brush development method, a pressure development method, and the like are known. Further, there is also used a method in which a magnetic toner is used and a rotating sleeve having a magnetic pole at the center is used to fly between the photosensitive member and the sleeve by an electric field.
[0004]
The one-component development method does not require carrier particles such as glass beads or iron powder as in the two-component method, so the development device itself can be reduced in size and weight. Furthermore, since the two-component development method needs to keep the toner concentration in the carrier constant, a device for detecting the toner concentration and supplying a necessary amount of toner is required. Therefore, the developing device is also large and heavy here. In the one-component development method, such an apparatus is not necessary, so that it is generally possible to make it relatively small and light.
[0005]
Also, LED and 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 300, 600 dpi is 1200, 2400 dpi. Accordingly, the development method is also required to have higher definition. In addition, copiers are also becoming more sophisticated, and therefore are moving toward digitalization. Since this method is mainly a method of forming an electrostatic latent image with a laser, it is also a high-resolution direction, and here again, a high-resolution and high-definition developing method is required as in the case of a printer.
[0006]
In order to achieve high resolution and high definition, it is necessary to reduce the toner particle size. However, when the toner particle size is reduced, the variation in chargeability of the toner particles increases, and the control thereof becomes important in order to achieve the object.
[0007]
For example, Japanese Patent Laid-Open No. 4-276762 proposes a toner in which specific carbon black is adhered to the surface of toner particles having an average particle diameter of 3 to 8 μm produced by a polymerization method. When the image is output using the toner in which the charge control material is arranged on the particle surface in this way, the carbon black adhering to the particle surface drops off when the number of passing sheets exceeds about 5000 sheets. As a result, the chargeability of the toner greatly fluctuates, resulting in insufficient charging stability.
[0008]
Further, as a proposal for imparting charging stability from the viewpoint of materials, for example, JP-A-6-242631 can be cited. However, when image evaluation was actually performed by the method described in the publication, there was still room for improvement in resolution.
[0009]
In order to make the charging property of the toner uniform, a method of strengthening the regulating force on the toner by a regulating member or the like is used. Increasing the toner's restrictive power tends to cause toner deterioration due to friction, and the image quality tends to decrease as the number of output images increases.
[0010]
Therefore, it is necessary to increase the strength of the toner. Generally solved by increasing the elastic modulus in the temperature range below the glass transition temperature of the toner by increasing the glass transition temperature of the binder resin of the toner or introducing a crosslinking component into the binder resin. As a result, the fixing temperature at the time of image formation must be increased, or in the case of fixing by a heat roller, the pressure applied by the roller must be set higher, so that the necessary heat energy can be obtained. Correspondingly, there are problems such as increased power consumption and increased frequency of roller contamination and winding offset.
[0011]
On the other hand, in order to lower the fixing temperature, there are methods of lowering the glass transition temperature and reducing the cross-linking component. However, such a method has the above-mentioned disadvantages and further reduces the blocking property during toner storage. Therefore, it is not preferable.
[0012]
In addition, various methods and apparatuses have been developed for fixing a toner image to a sheet such as paper or film. Currently, the most common method is a pressure heating method using a fixed heating heater via a heat roller or a heat-resistant film. It is.
[0013]
The pressure heating method using a heating roller fixes the toner image by passing the fixing sheet through the surface of the heat roller having releasability with respect to the toner and the toner image surface of the fixing sheet in contact with each other under pressure. Is. In this method, the surface of the heat roller and the toner image on the fixing sheet come into contact with each other under pressure, so that the thermal efficiency when fusing the toner image on the fixing sheet is extremely good, and the fixing is performed quickly. Can do.
[0014]
However, in such a fixing method, since the surface of the heating roller and the toner image are in a molten state and contacted under pressure, a part of the toner image adheres to the surface of the fixing roller and is transferred to the next fixing sheet. This re-transfers, and the so-called offset phenomenon that stains the fixing sheet tends to occur. Since such an offset phenomenon is greatly affected by the fixing speed and fixing temperature, generally, when the fixing speed is low, the surface temperature of the heating roller is set relatively low, and when the fixing speed is high, the surface of the heating roller is set. Attempts have been made to suppress the offset phenomenon by always adjusting the amount of heat applied to the toner from the heating roller to fix the toner by setting the temperature relatively high.
[0015]
Since the toner on the fixing sheet forms several toner layers, the toner layer contacting the heating roller and the fixing sheet are particularly fast in a system in which the fixing speed is high and the surface temperature of the heating roller is high. Because the temperature difference with the lowermost toner layer that is in contact is large, if the surface temperature of the heating roller is high, the toner on the uppermost layer tends to cause an offset phenomenon (high temperature offset), and the surface temperature of the heating roller is low. In this case, since the toner in the lowermost layer is not sufficiently dissolved, a phenomenon that the toner is not fixed on the fixing sheet (low temperature offset) is likely to occur.
[0016]
As a method for solving this problem, when the fixing speed is high, a method of increasing the pressure at the time of fixing and anchoring the toner to the fixing sheet is generally performed. With this method, the temperature of the heating roller can be lowered to some extent, and the high temperature offset phenomenon of the uppermost toner layer can be prevented. However, since the shearing force applied to the toner becomes very large, the fixing sheet winds around the fixing roller, causing a winding offset, or fixing after the separation claw for separating the fixing sheet from the fixing roller is fixed. It tends to appear in images. Furthermore, since the pressure is high, the actual situation is that the image quality of the fixed image is easily deteriorated such that the line image is crushed or toner is scattered during fixing.
[0017]
In high-speed fixing, a toner having a lower melt viscosity is generally used than in low-speed fixing, and the surface temperature of the heating roller is lowered, and the fixing pressure is lowered, thereby preventing a high-temperature offset and a winding offset while preventing a toner image. It has become established. However, when such a low melt viscosity toner is used for low-speed fixing, an offset phenomenon tends to occur at a high temperature.
[0018]
By reducing the particle size of the toner, the resolution and sharpness of the image are increased, while the fixability of the halftone portion formed of the toner having a small particle size is reduced. This phenomenon is particularly remarkable in high-speed fixing. This is because the amount of toner adhered to the halftone portion is small, the toner transferred to the concave portion of the fixing sheet has a small amount of heat applied from the heating roller, and the fixing pressure is also reduced to the concave portion by the convex portion of the fixing sheet. It is because it becomes worse because the pressure is suppressed. Since the toner transferred to the convex portion of the fixing sheet at the halftone portion has a thin toner layer thickness, the shear force applied to each toner particle is larger than that of the solid black portion where the toner layer thickness is thick. Phenomenon is likely to occur, and a low-quality fixed image tends to be obtained.
[0019]
In addition, in order to respond to the recent downsizing of devices, higher printing speeds, and networking, it is easier to simplify the fixing unit by expanding the anti-offset region of toner to the low temperature side, and the fixing temperature of toner is low. It is an effective method to increase the speed of the fixing process.
[0020]
Furthermore, in order to prevent the offset phenomenon, it is possible to process the surface of the heating roller with a material having excellent releasability such as fluorine resin, or to apply a release agent such as silicone oil to the surface of the heating roller. is there. However, the method of applying silicone oil or the like is not preferable because not only the fixing device becomes large and the cost increases, but also the device becomes complicated and may cause trouble.
[0021]
JP-B-57-493, JP-A-50-44836, and JP-A-57-37353 describe methods for improving the offset phenomenon by asymmetric and cross-linking the resin. However, the fixing temperature has not been improved sufficiently.
[0022]
Since the minimum fixing temperature is generally between the low temperature offset and the high temperature offset, the usable temperature range is between the minimum fixing temperature and the high temperature offset. By reducing the minimum fixing temperature as much as possible and increasing the high temperature offset generation temperature as much as possible. The use fixing temperature can be lowered and the usable temperature range can be widened, and energy saving, high-speed fixing, and curling of paper can be prevented. Therefore, a toner that always has good fixability and offset resistance is desired.
[0023]
Therefore, in JP-A-9-265209, the weight average molecular weight 3 × 10 ^Three ~ 1x10 ^Four Low molecular weight vinyl polymer component and weight average molecular weight 3 × 10 ^Five ~ 1x10 ⁶ The main component is a resin composition for toners containing 0.05 to 1 part of an antioxidant in 100 parts by weight of a vinyl polymer having as a main component a high molecular weight vinyl polymer component, and this is melt kneaded. After that, it is proposed that the fixing temperature region can be expanded by the toner obtained by cooling and pulverizing. However, with this method, the fixing region is only shifted to the low temperature side, and the offset on the high temperature side is likely to deteriorate.
[0024]
On the other hand, in Japanese Patent Application Laid-Open No. 8-26295, in a molecular weight distribution measured by gel permeation chromatography, a high molecular weight styrene-acrylic resin having a molecular weight peak in a region having a molecular weight of 500,000 or more, a molecular weight of 50,000 to 500,000. Have proposed a toner based on a styrene-acrylic resin having a peak in the region, a styrene-acrylic resin having a crosslinked structure, and a polyester resin binder resin having a molecular weight peak in a region having a molecular weight of 50,000 or less. Is still inadequate.
[0025]
In addition, a technique for improving low-temperature fixability has been proposed by using a capsule toner composed of a core material and an outer shell provided so as to cover the surface of the core material. Among them, it has been reported that when a low-melting-point wax that easily undergoes plastic deformation is used as the core material, fixing is possible only by pressure (US Pat. No. 3,269,626, Japanese Patent Publication No. Sho 46-15876, Japanese Patent Publication No. (Kokai 44-9880, JP-A 48-75032, JP-A 48-75033). However, the fixing strength is inferior, and it is used only for limited purposes. Also, when using a liquid material as the core material, if the strength of the shell material is small, it will be fixed only by pressure, but it may crack in the developing device and stain the inside of the machine. If the strength of the shell material is large, the capsule A large pressure is required to destroy the shell, resulting in an image with excessively high gloss, making it difficult to adjust the strength of the shell material.
[0026]
Therefore, for heat pressure fixing, when used alone as a core material, blocking occurs at high temperatures, but for the purpose of imparting blocking resistance and the like as an outer shell using a resin with a low glass transition point that brings about improvement in fixing strength. A capsule toner for heat roller fixing in which a resin wall having a high melting point is formed by interfacial polymerization has been devised (Japanese Patent Laid-Open No. 61-56352). However, since the wall material has a high melting point and is tougher and difficult to break, the performance of the core material has not been fully achieved.
[0027]
JP-A-8-286416 discloses a technique for coating an unsaturated polyester resin or styrene-acrylic resin by adsorbing and polymerizing a mixture of a polymerizable monomer and a particle obtained by suspension polymerization. Has been. According to this technique, it is possible to obtain a toner that is extremely excellent in durability and improved in terms of fixability as compared with the above-mentioned toner, but there is still room for improvement in terms of low-temperature fixability.
[0028]
Also, a heat roller fixing capsule toner having improved core core fixing strength based on the same concept has been proposed (Japanese Patent Laid-Open Nos. 58-205162, 58-205163, 63-128357). JP, 63-128358, JP 63-128359, JP 63-128360, JP 63-128361, JP 63-128362). However, since the manufacturing method is a spray-drying method, the manufacturing facilities are burdened, and since these are not devised for the shell material, the performance of the core material is not fully drawn out.
[0029]
Further, the capsule toner proposed in Japanese Patent Laid-Open No. 63-281168 has a description that the material is a thermotropic liquid crystal polyester, and the capsule toner proposed in Japanese Patent Laid-Open No. 4-184358 is crystalline. Although it is described as polyester, since polyester is not amorphous, the resin melts sharply, but the amount of energy required for melting is large, and the glass transition temperature of the core material is high, so the fixing property is inferior .
[0030]
As described above, capsule toners using various materials and manufacturing methods have been proposed. However, they satisfy all of sufficient low-temperature fixability, offset resistance, blocking resistance, and stress resistance in the developing unit. In particular, no quantitative value has been shown so far regarding the physical properties of the capsule toner that satisfies these performances.
[0031]
On the other hand, the capsule toner proposed in Japanese Patent Application Laid-Open No. 7-301947 defines the degree of deformation of the toner when a load is applied within a certain load range in a micro compression tester and the change in cohesion before and after heating. However, this alone does not take into account the toner deterioration in the development process, and is not always satisfactory.
[0032]
As a material, there has been proposed a thermoplastic elastomer and a toner which defines a storage elastic modulus at 200 ° C. (Japanese Patent Laid-Open No. 7-271096), but the effect is to improve the anti-offset property and prevent wrapping around the heat roller. Emphasis is placed on the image quality, which is still insufficient.
[0033]
As a toner using a polyene compound such as butadiene or isoprene which is a general-purpose material, it has been proposed in Japanese Patent Application Laid-Open No. 7-271096, but the effect is only to improve the anti-offset property and prevent wrapping around the heat roller. It is.
[0034]
For the reasons described above, in the fixing process, a toner having a wide fixing temperature range and excellent offset resistance is desired, but these points are sufficiently satisfied, and high resolution, high definition and charging are achieved. There is no toner that satisfies the stability.
[0035]
Further, regarding the toner production method, after the step of subjecting the polymerizable monomer composition to suspension polymerization in the presence of an oil-soluble polymerization initiator until the polymerization conversion is in the range of 30 to 97%, a water-soluble polymerization initiator is obtained. JP-A-11-160909 discloses a method for further polymerizing by adding. However, this method uses a macromonomer, and the reactivity does not reach that of a normal monomer, and is insufficient to obtain a toner having excellent durability.
[0036]
On the other hand, if residual toner remains on the photoconductor when the toner image formed on the photoconductor in the development process is transferred to the transfer material in the transfer process, it must be cleaned in the cleaning process and stored in a waste toner container. Comes out. For this cleaning process, conventional blade cleaning, fur brush cleaning, roller cleaning, and the like are used. In either method, the transfer residual toner is mechanically scraped or damped and collected in a waste toner container. Therefore, there is a problem caused by such a member being pressed against the surface of the photoreceptor. For example, in the case of using a toner having a large amount of transfer residue, it is necessary to strongly press the member, and the photoconductor is worn, so that the life can be shortened.
[0037]
From the standpoint of the apparatus, since the apparatus is inevitably large in order to have such a cleaning apparatus, it has become a bottleneck when attempting to make the apparatus compact. Furthermore, from the viewpoint of ecology, a system without waste toner is desired in terms of effective use of toner.
[0038]
Here, technologies relating to cleanerless are disclosed in Japanese Patent Application Laid-Open Nos. 59-133573, 62-203182, 63-133179, and 64-20587. No. 2, JP-A-2-302277, JP-A-5-2289, JP-A-5-53482, JP-A-5-61383, and the like, however, a desirable toner configuration is not mentioned.
[0039]
In a developing and cleaning configuration that essentially does not have a cleaning device, the surface of the photosensitive member is rubbed with toner and a toner carrier, the toner of the non-image portion is collected with the toner carrier, and the image portion is developed with toner. Configuration is required. If the reversely charged toner such as the transfer residual toner or fog toner can be easily reversed at the time of this rubbing, electrical recovery becomes easy. For this purpose, one means is to add a polar component to the toner.
[0040]
That is, the toner containing many polar components uses the general phenomenon that the charging speed is fast, but as described above, it has almost the polarity of polyethylene or polypropylene for improving the offset property of the toner. In the case where a release agent is added, the charging speed of the toner is lowered, and the smooth recovery of the toner on the photoreceptor in the developing process is hindered. As a result, an area without an image becomes a printed image that is smeared with toner by a toner image, a so-called ghost image.
[0041]
As described above, in the development and cleaning configuration, a technique for achieving both toner fixing properties and image characteristics is desired. Furthermore, it can be said that the technique of collecting toner in the developing process is very important even in a system in which the pressing of the member is weakened in order to extend the life of the photoreceptor.
[0042]
[Problems to be solved by the invention]
An object of the present invention is to provide a dry toner that solves the above problems.
[0043]
An object of the present invention is to provide a dry toner having excellent charge stability.
[0044]
An object of the present invention is to provide a dry toner that can obtain a high-definition and high-definition image and is excellent in fixability and offset resistance.
[0045]
An object of the present invention is to provide a toner capable of stably obtaining a high-quality image over a long period of time.
[0046]
Another object of the present invention is to use a dry toner, a method for producing the toner, and the toner that are highly applicable to an electrophotographic process that does not adversely affect a photosensitive member, a toner carrier, and an intermediate transfer member. An object is to provide an image forming method.
[0047]
Furthermore, the object of the present invention is to improve the resolution and transferability while maintaining the fixability in the contact development type image forming process using a cleaner-less structure or an intermediate transfer body, thereby improving the toner recoverability. An object of the present invention is to provide an electrophotographic image forming method capable of suppressing the occurrence of ghost and further improving the durability.
[0048]
[Means for Solving the Problems]
The present invention is a dry toner having toner particles containing at least a binder resin, a colorant, and a wax component and an external additive,
[0049]
(1) The binder resin contains a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene,
(2) The main glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the toner is 40 to 70 ° C.,
(3) The specific surface area according to the BET method when the toner is left for 72 hours in an environment having an ambient temperature of 23 ° C. and a relative humidity of 65% is expressed as A (m ² / G), the specific surface area according to the BET method when the toner is left for 72 hours in an environment with an ambient temperature of 50 ° C. and a relative humidity of 3% is expressed as B (m ² / G), A and B satisfy the following formula:
0.8 ≦ A ≦ 4.0
0.80 ≦ (B / A) ≦ 1.05
(4) In the toner-based circle-equivalent diameter-circularity scattergram measured by the toner flow-type particle image measuring device, the circle equivalent number average diameter D1 of the toner is 2 to 10 μm. The average circularity is 0.950 to 0.995, the circularity standard deviation is less than 0.040,
(5) The tetrahydrofuran (THF) soluble content of the toner has a main peak molecular weight of 2 × 10 in the molecular weight distribution measured by gel permeation chromatography (GPC). ^Three ~ 1x10 ^Five The THF-insoluble content is 5 to 60% by mass,
The present invention relates to a dry toner.
[0050]
Furthermore, the present invention provides a diene monomer component-containing resin containing a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene, a polymerizable vinyl monomer, a colorant, a wax, and A method for producing toner particles by dispersing and granulating a polymerizable monomer composition containing a polymerization initiator in an aqueous medium and polymerizing in an aqueous medium,
The present invention relates to a method for producing a dry toner, wherein the polymerization initiator is a radical polymerization initiator and a radical polymerization initiator is newly added when the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass. .
[0051]
Further, the present invention provides a charging step of applying a voltage to the charging member to charge the electrostatic latent image carrier, and forming an electrostatic latent image on the charged electrostatic latent image carrier. A developing step for forming a toner image on the electrostatic latent image carrier by attaching the toner carried on the toner carrier to the electrostatic latent image formed on the electrostatic latent image carrier; and A transfer process in which the toner image formed on the electrostatic latent image carrier is electrostatically transferred to the transfer material with or without the intermediate transfer member, and the toner image electrostatically transferred to the transfer material is fixed. An image forming method comprising a fixing step,
[0052]
The toner is a dry toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an external additive,
(1) The binder resin contains a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene,
(2) The main glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the toner is 40 to 70 ° C.,
(3) The specific surface area according to the BET method when the toner is left for 72 hours in an environment having an ambient temperature of 23 ° C. and a relative humidity of 65% is expressed as A (m ² / G), the specific surface area according to the BET method when the toner is left for 72 hours in an environment with an ambient temperature of 50 ° C. and a relative humidity of 3% is expressed as B (m ² / G), A and B satisfy the following formula:
0.8 ≦ A ≦ 4.0
0.80 ≦ (B / A) ≦ 1.05
(4) In the toner-based circle-equivalent diameter-circularity scattergram measured by the toner flow-type particle image measuring device, the circle equivalent number average diameter D1 of the toner is 2 to 10 μm. The average circularity is 0.950 to 0.995, the circularity standard deviation is less than 0.040,
(5) The tetrahydrofuran (THF) soluble content of the toner has a main peak molecular weight of 2 × 10 in the molecular weight distribution measured by gel permeation chromatography (GPC). ^Three ~ 1x10 ^Five The THF-insoluble content is 5 to 60% by mass,
The present invention relates to an image forming method.
[0053]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0054]
<1> Dry toner of the present invention
The dry toner of the present invention (hereinafter referred to as “toner”) has toner particles containing at least a binder resin, a colorant and a wax component, and inorganic fine powder.
[0055]
The binder resin in the toner of the present invention contains a component derived from at least one monomer selected from butadiene, isoprene and chloroprene (hereinafter also referred to as “diene monomer”).
[0056]
None of the above diene monomers contains oxygen atoms. Therefore, there is no site for moisture in the air to be adsorbed, so that charge leakage is unlikely to occur in the toner. Therefore, the influence of humidity on the charge amount is reduced, and as a result, the chargeability of the toner is stabilized. Furthermore, since two double bonds capable of radical polymerization are included in one molecule, a three-dimensional structure can be easily formed, which may be caused by, for example, the effect of increasing the viscosity or the formation of a network structure. For this reason, the presence of the (semi) dissolved / dispersed material in the toner particles, such as pigments and charge control agents, is improved and the chargeability is stabilized without much influence of the manufacturing method. Is considered to be able to improve the color of the toner. When a monomer such as styrene or hydrogenated vinylcyclohexane is used, the former effect can be obtained by the absence of oxygen atoms, but the latter by having two double bonds in one molecule. This effect is difficult to obtain due to the characteristics of the monomer. Furthermore, in monomers such as divinylbenzene, when both double bonds in one molecule react, the structure is cross-linked by a rigid benzene ring, and the flexibility between the cross-linking points of the polymer is lost, and fixing properties are lost. May cause adverse effects on the skin and may increase brittleness. For the reasons described above, the diene monomer is used as an essential component in the present invention.
[0057]
In addition, since the boiling points of butadiene, chloroprene, and isoprene are all -4.5 ° C, 59.4 ° C, and 34.1 ° C, and they are highly volatile at normal pressure, toners produced by the suspension polymerization method described later. If the diene monomer is directly introduced into the diene monomer, there is a high possibility that the diene monomer volatilizes during the polymerization. Therefore, suspension polymerization under pressure is performed, or the resin is previously obtained by another means. Preferably it is produced and added. The latter is more preferable for quantitative introduction into the toner.
[0058]
The resin containing a diene monomer is preferably solution polymerization, emulsion polymerization, soap-free polymerization or the like under pressure.
[0059]
As the resin containing a diene monomer used for suspension polymerization, a resin polymerized with a polymerization initiator having a carboxyl group or a sulfate group is also preferably used. The reason is that the diene monomer-containing resin is easily localized in the vicinity of the toner particle surface obtained by incorporating a polar group in the polymer, and the effect of improving durability can be obtained by taking a three-dimensional structure. Because.
[0060]
In the present invention, the total content of components derived from butadiene, isoprene and chloroprene contained in the binder resin is preferably 0.1 to 20% by mass with respect to the toner.
[0061]
The toner has a peak molecular weight of 5 × 10 in the molecular weight distribution measured by GPC of the THF soluble content of the toner in order to prevent low temperature and high temperature offset. ^Five High molecular weight resin or cross-linked resin exceeding 1 and the molecular weight distribution of the molecular weight distribution measured by GPC of the THF soluble part of the toner 1 × 10 ^Three ~ 5x10 ^Four In general, the viscoelasticity of a toner is designed by using a low molecular weight resin of a certain degree as a binder resin. The content of the diene monomer in the binder resin is 20% by mass. If it exceeds the above range, it may be difficult to produce a toner having such a design, which may cause problems. Accordingly, the content of the diene monomer preferably does not exceed 20% by mass in the toner, and more preferably in the range of 0.1 to 10% by mass. Further, if the content of the diene monomer in the binder resin is less than 0.1% by mass, the stabilization of charging, which is the effect of the present invention, cannot be sufficiently achieved, and a high-resolution and high-definition image can be obtained. It may not be obtained.
[0062]
The measurement of the content of the diene monomer contained in the toner of the present invention is not particularly limited, but it can be performed by combining a pyrolysis gas chromatograph and a mass spectrum, elemental analysis, and other measurement methods. . Also, the amount of diene monomer contained in the THF soluble content in the toner is ¹ H-NMR, ¹³ It is also possible to estimate the amount of diene monomer component by quantifying with C-NMR or the like.
[0063]
As the monomer constituting the binder resin in the present invention, as described above, a monomer selected from the group consisting of butadiene, chloroprene, and isoprene (hereinafter, also referred to as “diene monomer”) is an essential component. Although it is not particularly limited as long as it is contained, examples of other monomers constituting the binder resin include styrene, o (m-, p-)-methylstyrene, and m (p-)-ethylstyrene. Styrene monomer; methyl (meth) acrylate, ethyl (meth) acrylate, (n-propyl) (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth) Isobutyl acrylate, (meth) acrylic acid-t-butyl, (meth) acrylic acid pentyl, (meth) acrylic acid hexyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid-2-ethylhexyl, Adamantyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth) acrylic acid (Meth) acrylic acid ester monomers such as diethylaminoethyl; maleic acid ester monomers such as dimethyl maleate and diethyl maleate; vinyl ether monomers such as ethyl vinyl ether and cyclohexyl vinyl ether; (meth) Monomers such as acrylic acid, maleic acid, fumaric acid, maleic anhydride, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. These may be used alone or in combination of two or more.
[0064]
Among these, styrene monomers such as styrene and styrene derivatives are preferable because they are excellent in charging stability of the toner when copolymerized with a diene monomer. The binder resin in the present invention is preferably a copolymer of the above styrene monomer and a diene monomer, particularly a copolymer of butadiene.
[0065]
In addition, a resin containing a diene monomer used as a binder resin in the present invention as an essential component (hereinafter referred to as “diene monomer component-containing resin”) is an epoxy resin for improving toner charging stability. , May be modified with maleic anhydride, maleic acid (half) ester, and / or methacrylic acid derivatives.
[0066]
Further, as the binder resin in the present invention, the above-mentioned diene monomer component-containing resin, polystyrene, styrene- (meth) acrylic copolymer, general polyester, polyurethane, epoxy resin, polyolefin, polyamide, polysulfone, polycyano A block copolymer with an aryl ether or polyarylene sulfide, or a graft-modified copolymer obtained by grafting an alkyl (meth) acrylate, (meth) acrylic acid, maleic acid or styrene monomer to a resin containing a diene monomer component Can also be used.
[0067]
In the present invention, other resins may be used in combination with the diene monomer component-containing resin. Examples of other resins used in combination with the diene monomer component-containing resin include various resins such as commonly used styrene-acrylic resins, polyester resins, and epoxy resins.
[0068]
These resins can be obtained by polymerizing the monomers shown below. Specific monomers include styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, (meth) acrylic Ethyl acid, (meth) acrylic acid-n-propyl, (meth) acrylic acid isopropyl, (meth) acrylic acid-n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-t-butyl, (meth) Pentyl acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, adamantyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate (Meth) such as, behenyl (meth) acrylate, isobornyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate Kuryl ester monomers; Maleate monomers such as dimethyl maleate and diethyl maleate; Vinyl ether monomers such as ethyl vinyl ether and cyclohexyl vinyl ether; (Meth) acrylic acid, maleic acid and fumar And monomers such as acid, maleic anhydride, butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide. These may be used alone or in combination of two or more.
[0069]
In the present invention, the resin used in combination with the diene monomer component-containing resin is preferably contained in the binder resin in an amount of 50 to 99.9% by mass, more preferably 80 to 99.9% by mass, 85 to 99.5 mass%, particularly preferably 85 to 98 mass% is preferable. The type of resin is preferably a styrene-acrylic resin.
[0070]
The resin used in combination with the above-mentioned diene monomer component-containing resin is used alone or by appropriately mixing the above monomers so that the theoretical glass transition temperature (Tg) is 40 to 75 ° C. In order to make the theoretical glass transition temperature (Tg) as described above, generally, the method described in publication polymer handbook 2nd edition, pages III-139 to 192 (manufactured by John Wiley & Sons) can be mentioned. Similarly, when other resins are used in combination, the above-mentioned monomers are used appropriately or individually so that the theoretical glass transition temperature (Tg) is 40 to 75 ° C.
[0071]
When the theoretical glass transition temperature is less than 40 ° C., problems are likely to occur from the viewpoint of storage stability and durability stability of the toner, whereas when it exceeds 75 ° C., the fixing point of the toner may be increased. In particular, in the case of a color toner for forming a full-color image, the color mixing property at the time of fixing each color toner is lowered, the color reproducibility is poor, and the transparency of the OHP image is further lowered.
[0072]
The toner of the present invention contains a colorant and a wax component in addition to the binder resin.
[0073]
The toner in the present invention contains a wax component used as a release agent such as a hydrocarbon compound, a higher fatty acid, a higher alcohol, or a derivative thereof in the toner for the purpose of improving the release property at the time of fixing with a hot roll. It is preferable to mix. Specific examples of such wax components include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof, alcohol, fatty acid, acid amide , Esters, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, mineral waxes, petrolactams, and derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. included.
[0074]
These wax components may be used alone or in combination of two or more.
[0075]
These wax components have a maximum endothermic peak in the 40 to 130 degree region at the time of temperature rise in the DSC curve measured by a differential scanning calorimeter. By having the maximum endothermic peak in the above temperature range, the mold releasability is effectively expressed while greatly contributing to low-temperature fixing. When the maximum endothermic peak is less than 40 ° C., the self-aggregation force of the wax component becomes weak, resulting in poor high temperature offset resistance and excessive gloss.
[0076]
On the other hand, if the maximum endothermic peak exceeds 130 ° C., the fixing temperature becomes high and it becomes difficult to appropriately smooth the surface of the fixed image. It is not preferable. Further, in the case where granulation / polymerization is performed in an aqueous medium and a toner is directly obtained by the polymerization method, if the maximum endothermic peak temperature is high, problems such as precipitation of a wax component mainly during granulation are undesirable.
[0077]
The maximum endothermic peak temperature of the wax component is measured according to “ASTM D 3418-8”. For the measurement, for example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, an empty pan is set as a control, and measurement is performed at a heating rate of 10 ° C./min. In the present invention, the addition amount of these wax components is not particularly limited, but is preferably 0.5 to 30% by mass with respect to the toner.
[0078]
As the colorant used in the toner of the present invention, conventionally known inorganic / organic dyes / pigments can be used, and examples thereof include the following yellow colorant, magenta colorant, and cyan colorant.
[0079]
Further, carbon black, aniline black, acetylene black, a magnetic material, a fired pigment, or a mixture of the following yellow colorant / magenta colorant / cyan colorant mixed with black may be used as the black colorant. .
[0080]
When carbon black is used for the toner of the present invention, the primary particle size is preferably 25 to 80 nm. When the particle size of the carbon black is smaller than 25 nm, the primary particle size is so fine that sufficient dispersion is difficult to obtain and it may be difficult to use it. If it is larger than 80 nm, there may be inconveniences such that only a low density image can be obtained or the toner consumption increases due to insufficient coloring power as a toner even if it is dispersed well. Further, regarding the particle size of the carbon black, it is more preferable that the particle size is 35 to 70 nm, and the charge polarity and charge amount of the transfer residual toner by the charging member can be controlled more reliably and uniformly, and the charge amount of the toner It is more advantageous in terms of the stability of the toner and the toner coloring power.
[0081]
Furthermore, the toner of the present invention uses a magnetic material as a black colorant and can also be used as a magnetic toner. Magnetic materials that can be used at this time include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, and antimony , Alloys with metals such as beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium; and mixtures thereof.
[0082]
The magnetic material used in the present invention is more preferably a surface-modified magnetic material. When used in a polymerization toner, the magnetic material is subjected to a hydrophobic treatment with a surface modifier that is a substance that does not inhibit polymerization. Is preferred. Examples of such surface modifiers include silane coupling agents and titanium coupling agents.
[0083]
These magnetic materials preferably have an average particle size of 2 μm or less, more preferably about 0.1 to 0.5 μm. The amount of the magnetic substance to be contained in the toner particles is 20 to 200 parts by mass, particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin. In addition, the magnetic characteristics under application of 796 kA / m (10 kilo-Oersted) are coercive force (Hc) of 1580 to 23700 A / m (20 to 300 Oersted), and saturation magnetization (σs) of 50 to 200 Am. ² / Kg (emu / g), residual magnetization (σr) 2-20 Am ² A magnetic substance of / kg (emu / g) is preferable.
[0084]
As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 are preferably used.
[0085]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 26, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are particularly preferred.
[0086]
As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds can be used. Specifically, CI pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 can be used particularly preferably.
[0087]
These colorants can be used alone or in combination and further in the form of a solid solution. The colorant is selected in terms of hue, saturation, brightness, weather resistance, OHP transparency, and dispersibility in toner particles. The added amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.
[0088]
When a magnetic material is used as the black colorant, it is preferable to use 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin, unlike other colorants.
[0089]
The toner of the present invention may contain a charge control agent. As the charge control agent to be used, a known one can be used, and in particular, charge control that can maintain a constant charge amount with a high charge speed is possible. Agents are preferred. Further, when the toner particles are produced using a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, naphthoic acid, and dicarboxylic acid, polymer compounds having a sulfonic acid or carboxylic acid group in the side chain, boron compounds, Examples include urea compounds, silicon compounds, and calixarenes. Examples of positive charge control agents include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, and imidazole compounds. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.
[0090]
In the present invention, the addition of a charge control agent is not essential. When a two-component development method is used, friction charging with a carrier is used. When a nonmagnetic one-component blade coating development method is used, a blade member is used. It is also possible to positively use the triboelectric charging.
[0091]
If a charge control agent is used in the toner of the present invention, among the above compounds, compounds represented by the following general formula (I) are more preferable.
[0092]
Formula (I)
[Outside 2]

[0093]
[Where X ₁ And X ₂ Represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, ₁ And X ₂ May be the same or different, m and m ′ represent an integer of 1 to 3; ₁ And R _Three Is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, a sulfonamide group, a mesyl group, a sulfonyl group, a hydroxyl group, an alkoxy group having 1 to 18 carbon atoms, an acetylamino group, or benzoylamino Group, halogen atom or -COOR _Five Represents R ₁ And R _Three May be the same or different, and n and n ′ represent an integer of 1 to 3, ₂ And R _Four Represents a hydrogen atom or a nitro group, R _Five Represents an alkyl group or an aryl group, and A ⁺ Represents hydrogen ion, sodium ion, potassium ion or ammonium ion. ]
[0094]
X ₁ And X ₂ Examples of the lower alkyl group include an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, and a propyl group. Examples of the lower alkoxy group of X1 and X2 include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group.
[0095]
X ₁ , X ₂ , R ₁ And R _Three Examples of the halogen atom include fluorine, bromine, chlorine, and iodine.
[0096]
X ₁ And X ₂ Examples of preferred groups include a hydrogen atom or a nitro group.
[0097]
R ₁ And R _Three Examples of the alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, and hexyl group.
[0098]
R ₁ And R _Three Examples of the alkenyl group having 1 to 18 carbon atoms include a vinyl group, an allyl group, a propenyl group, and a butenyl group.
[0099]
R ₁ And R _Three Examples of the alkoxy group having 1 to 18 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
[0100]
Also R ₁ And R _Three Is -COOR _Five In this case, R may be used. _Five Includes a methyl group, an ethyl group, a propyl group, a phenyl group, and a naphthyl group.
[0101]
Of these, preferred R ₁ And R _Three As chlorine.
[0102]
Preferred R ₂ And R _Four Examples of the hydrogen include hydrogen.
[0103]
Preferable specific examples of the charge control agent include compounds represented by the following general formulas (II) and (III).
[0104]
[Outside 3]

[0105]
[Outside 4]

[0106]
The charge control agent is preferably used in an amount of 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin.
[0107]
In the toner of the present invention, an external additive is mixed with the toner particles in order to improve charging stability, developability, fluidity, and durability.
[0108]
As the external additive used in the present invention, first, inorganic fine powder is exemplified. Specific examples include fine silica powder, titanium oxide, and fine alumina powder, and particularly fine silica powder is preferably used. Among these, the specific surface area by nitrogen adsorption measured by the BET method is 30 m. ² / G or more, especially 50-400m ² Those in the / g range give good results. The inorganic fine powder is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles. The specific surface area of the inorganic fine powder can be calculated by the method described later in the BET method in the same manner as the specific surface area of the toner.
[0109]
The inorganic fine powder used in the present invention is made of silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, etc. It is preferable to treat with a treating agent such as an organosilicon compound. In particular, hydrophobic silica treated with a silicone oil and / or a silane coupling agent is preferred.
[0110]
Other external additives contained in the toner of the present invention include lubricants such as Teflon, zinc stearate, and polyvinylidene fluoride (in particular, polyvinylidene fluoride is preferable); abrasives such as cerium oxide, silicon carbide, and strontium titanate. (Especially strontium titanate is preferable); anti-caking agent; conductivity imparting agent such as carbon black, zinc oxide, antimony oxide, tin oxide; developability improver such as white fine particles and black fine particles having opposite polarity to toner particles It is done.
[0111]
In the present invention, in the case of a toner produced by adding inorganic fine powder or other external additives to toner particles, and stirring and mixing them, measurement of various physical property values of the toner particles described later is performed using these inorganic particles. It can be carried out using toner particles after removing fine particles and other external additives. The method for removing these inorganic fine particles and other external additives from the surface of the toner particles is not particularly limited, but for example, it can be carried out by washing the toner with water as follows.
[0112]
First, toner is added to water to which a surfactant such as sodium dodecylbenzenesulfonate is added, and the mixture is sufficiently stirred and mixed. By this operation, inorganic fine particles and other external additives having a relatively large particle size are released from the toner particles, and the toner particles, inorganic fine particles and other external additives are separately dispersed in water. The toner particles are then isolated from this mixed dispersion. As an isolation method, for example, by performing a filtration operation using a paper with an appropriate opening, it can be separated as an aqueous solution containing toner particles on the paper and inorganic fine particles and other external additives in the filtrate. it can. As another isolation method, a method of isolating the toner particles by wet classification of the mixed dispersion can be employed.
[0113]
The toner of the present invention has a main glass transition temperature (Tg) observed at 40 to 70 ° C. in a DSC curve measured by a differential scanning calorimeter. In the present invention, when a plurality of resins having different glass transition temperatures are used, a plurality of glass transition temperatures may be observed in DSC. In that case, the larger endothermic amount is defined as the main glass transition temperature.
[0114]
If the main glass transition temperature is less than 40 ° C., the flow resistance in the developing device is lowered due to a decrease in the blocking resistance of the toner, and it is very easy to fuse on the toner carrier or electrostatic latent image carrier. Therefore, it is not preferable. When the temperature exceeds 70 ° C., the melt viscosity of the toner given a certain amount of heat increases, and as a result, the fixing temperature increases. That is, in order to increase the amount of heat required or to fix with the same amount of heat, for example, the pressure applied to the transfer material must be increased, which is not preferable. A more preferable glass transition temperature of the toner of the present invention is 42 to 68 ° C, particularly 45 to 65 ° C.
[0115]
The DSC curve of the toner in the present invention can be measured by a differential scanning calorimeter of high accuracy internal heat input compensation type from the measurement principle. For example, DSC-7 manufactured by Perkin Elmer can be used. The measuring method can be performed according to “ASTM D3418-8”. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, an empty pan is set for control, and the measurement can be performed at a heating rate of 10 ° C./min.
[0116]
Specifically, the glass transition temperature (Tg) can be measured by the following method.
[0117]
After the sample has been heated up and cooled, the glass transition temperature (Tg) at the intersection of the baseline before the endothermic peak and the baseline between the endothermic peak and the rising curve from the DSC curve at the second temperature rise. (See FIG. 8).
[0118]
In order for the toner to have a glass transition temperature (Tg) of 40 to 70 ° C. observed in a DSC curve measured by a differential scanning calorimeter, specifically, the type and ratio of the polymerizable monomer are changed. Change and adjust.
[0119]
The toner according to the present invention has a specific surface area of A (m) measured by the BET method when left in an environment having an ambient temperature of 23 ° C. and a relative humidity of 65% for 72 hours. ² / G), the specific surface area according to the BET method when the toner is allowed to stand for 72 hours in an environment having an atmospheric temperature of 50 ° C. and a relative humidity of 3% is represented by B (m ² / G), the relational expressions 0.8 ≦ A ≦ 4.0 and 0.80 ≦ (B / A) ≦ 1.05 are satisfied. If A is less than 0.8, it becomes difficult to control the fluidity of the toner, and it may become difficult to obtain a high-resolution image. If it exceeds 4.0, the chargeability of the toner may be reduced. A high quality image may be difficult to obtain due to increased variation or inferior matching with the toner carrier or electrostatic latent image carrier. Furthermore, the range of 1.0 ≦ A ≦ 3.0 is more preferable. The value of (B / A) is preferably in the range of 0.85 ≦ (B / A) ≦ 1.05, and more preferably in the range of 0.90 ≦ (B / A) ≦ 1.05. In particular, 0.92 ≦ (B / A) ≦ 1.03, and most preferably 0.92 ≦ (B / A) ≦ 1.00.
[0120]
The decrease in (B / A) indicates that an external additive such as silica existing on the toner surface is buried by being left in an environment having an atmospheric temperature of 50 ° C. and a relative humidity of 3% for 72 hours. When the value is less than 0.80, there is a tendency that a high-quality image cannot be stably obtained. When (B / A) exceeds 1.05, it means that the toner particles themselves are largely deformed, and it is still impossible to stably obtain a high-quality image.
[0121]
The specific surface area by the BET method in the present invention is, for example, a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) was used to adsorb nitrogen gas on the sample surface, and the specific surface area was calculated using the BET multipoint method. Is.
[0122]
A method for producing a toner that satisfies the above-mentioned regulations relating to the BET specific surface area is not particularly limited. For example, resin particles containing a diene monomer are produced by a pulverization method or a polymerization method, and a diene existing near the surface is produced. This can be achieved by reacting the unreacted double bond of the monomer.
[0123]
The toner particles thus obtained increase in strength by taking a three-dimensional structure without greatly impairing the flexibility of the particle surface. Therefore, even when the toner is left in a high temperature and high humidity environment, the external additive is hardly embedded in the toner particles, and deformation of the toner particles themselves is suppressed. In addition, since a network structure of the diene monomer is formed on the surface of the toner, it is less affected by moisture in the air, and further stabilization of charging is achieved.
[0124]
The toner production method of the present invention will be described in detail later.
[0125]
The toner of the present invention needs to have the following shape in order to improve transferability and developability with a good balance. That is, the number average diameter corresponding to the circle in the particle number frequency distribution based on the number of toners is 2 to 10 μm, and the average circularity in the circularity frequency distribution is 0.950 to 0.995, preferably 0.960 to 0.995. More preferably, the transferability and development are controlled by precisely controlling the toner particle shape so that the circularity standard deviation is less than 0.040, preferably less than 0.035. The sex can be improved in a well-balanced manner.
[0126]
By reducing the number average diameter corresponding to the circle in the particle size frequency distribution on the basis of the number of toners to 2 to 10 μm, the reproducibility in developing the contour portion of an image, particularly a character image or a line pattern is improved. Become. However, in general, when the toner particle size is reduced, the presence rate of the toner having a small particle size inevitably increases, so that it is difficult to uniformly charge the toner and image fogging occurs. There is a tendency that the adhesion force to the body surface is increased, resulting in an increase in the residual toner.
[0127]
However, the toner of the present invention has good stability with respect to environmental fluctuations in developability and transferability as well as durability by controlling the circularity standard deviation of the circularity frequency distribution as described above. The reason is that when a toner thin layer is formed on the toner carrier in the development step, a sufficient toner coat amount can be maintained even if the regulating force of the toner layer thickness regulating member is made stronger than usual. This is considered to be because the charge amount of the toner on the toner carrier can be made higher than usual without damaging the toner carrier.
[0128]
By setting the average circularity in the circularity frequency distribution to 0.950 to 0.995, more preferably 0.970 to 0.995, the transferability of toner exhibiting a small particle diameter, which has been conventionally considered difficult, is improved. In addition to being greatly improved, the developing ability for a low potential latent image can be remarkably improved. This is particularly effective when developing a digital microspot latent image. When the average circularity is less than 0.950, not only transferability but also developability may be deteriorated. On the other hand, when the average circularity exceeds 0.995, the toner surface is remarkably deteriorated, which tends to cause a problem in durability.
[0129]
In a spherical toner having an average circularity of 0.950 to 0.995, the particles usually come into contact with each other at a point, so that the pressure at the contact point increases, and the external additive present on the surface of the toner particle is reduced. It is easy to be embedded in toner. However, since the toner of the present invention has a network structure formed of a diene monomer on the surface of the toner particles, the surface strength is high and embedding of the external additive is suppressed. For this reason, even when used over a long period of time, the initial excellent characteristics are maintained. This tendency is particularly remarkable in the toner having an average circularity of 0.970 to 0.995.
[0130]
Further, when the intermediate transfer method is performed in the transfer process in order to cope with various transfer materials, the transfer process is performed substantially twice, so that in general, the transfer efficiency decrease rate is a problem that causes a significant decrease in toner utilization efficiency. Become. In digital full-color copying machines and printers, color image originals are color-separated beforehand using a B (blue) filter, a G (green) filter, and an R (red) filter, and then a dot latent image of 20 to 70 μm is formed on the photoreceptor. A multi-color image faithful to the original is reproduced by using a subtractive color mixing action using each color toner of Y (yellow) toner, M (magenta) toner, C (cyan) toner, and B (black) toner. There is a need. At this time, a large amount of each color toner of Y toner, M toner, C toner, and B toner is placed on the photosensitive member or intermediate transfer member corresponding to the color information of the document or CRT. The color toner is required to have extremely high transferability. In order to satisfy such higher level requirements, the average circularity of the toner described above is 0.950 to 0.995, preferably 0.970 to 0.995, and the circularity standard deviation is 0.040. Less than, preferably less than 0.035.
[0131]
The toner of the present invention preferably contains 15% by number or less of toner having a circularity of less than 0.950 in a number-based equivalent circle diameter-circularity scattergram measured by the flow particle image measuring apparatus. . It is not preferable that the toner having a circularity of less than 0.950 exceeds 15% by number because the residual toner after transfer tends to increase.
[0132]
The circularity in the present invention is used as a simple method for quantitatively expressing the particle shape. In the present invention, the particle shape is measured using a flow particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics. The circularity is obtained by the following formula. Furthermore, as shown by the following equation, a value obtained by dividing the total roundness of all the measured particles by the total number of particles is defined as the average circularity.
[0133]
[Outside 5]

[0134]
Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define.
[0135]
In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the circularity standard deviation. Degrees of 0.400 to 1.000 at intervals of 0.010, 0.400 or more and less than 0.410, 0.410 or more and less than 0.420 ... 0.990 or more and less than 1.000 and 1.000 A calculation method is used in which the average circularity and the circularity standard deviation are calculated using the center value and frequency of the division points.
[0136]
Error between each value of average circularity and circularity standard deviation calculated by this calculation method and each value of average circularity and circularity standard deviation calculated by the above-described calculation formula that directly uses the circularity of each particle. Is very small and substantially negligible. Therefore, in the present invention, the circular shape of each particle described above is used for the reason of handling data such as a short calculation time and a simplified calculation formula. This calculation method is partially modified by using the concept of a calculation formula that directly uses the degree.
[0137]
The circularity in the present invention is an index indicating the degree of unevenness of particles, and is 1.000 when the particles are completely spherical, and the circularity becomes smaller as the surface shape becomes more complicated.
[0138]
The equivalent circle diameter is
[0139]
[Outside 6]

[0140]
The circle-equivalent number average diameter (D1) represents the average value of the equivalent circle diameter of the toner based on the number, and the particle size (center value) at the division point i of the particle size distribution is di, When the frequency is fi, it is expressed as follows.
[0141]
[Outside 7]

[0142]
The division points of the particle size distribution in the present invention are as shown in the following table.
[0143]
[Table 1]

[0144]
As a specific measurement method, for example, 10 ml of ion-exchanged water from which impure solids have been previously removed is prepared in a container, and after adding a surfactant, preferably an alkylbenzene sulfonate as a dispersant, Further, 0.02 g of a measurement sample is added and dispersed uniformly. As a means for dispersion, an ultrasonic disperser UH-50 type (manufactured by SMT Corporation) equipped with a titanium alloy chip having a diameter of 5 mm as a vibrator is used, and a dispersion for measurement is made using a dispersion treatment for 5 minutes. . In that case, it cools suitably so that the temperature of the said dispersion liquid may not become 40 degreeC or more.
[0145]
As a specific method for measuring the circularity and the equivalent circle diameter, about 5 mg of toner is dispersed in 10 ml of water in which about 0.1 mg of a nonionic surfactant is dissolved, and a dispersion liquid is prepared, and ultrasonic waves (20 kHz, 50 W) are prepared. ) To the dispersion for 5 minutes, the dispersion concentration is 5000 to 20000 particles / μl, and the circularity of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm using the above flow type particle image measuring apparatus. Measure the distribution.
[0146]
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.
[0147]
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. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above circularity calculation formula. In the present invention, particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm are measured.
[0148]
In order to make the shape of the toner as described above, specifically, in the case of the polymerization method toner, the polymerization method and polymerization temperature may be adjusted, and in the case of the pulverized toner, the pulverization conditions may be adjusted.
[0149]
The tetrahydrofuran (THF) soluble content of the dry toner of the present invention has a main peak molecular weight of 2 × 10 in the molecular weight distribution measured by gel permeation chromatography (GPC). ^Three ~ 1x10 ^Five And the THF-insoluble content is 5 to 60% by mass.
[0150]
In the present invention, the molecular weight of the binder resin in the toner is a value obtained as a molecular weight in terms of polystyrene from the molecular weight distribution in GPC. In the toner of the present invention, the molecular weight distribution measured by GPC of THF soluble content is 2 × 10. ^Three ~ 1x10 ^Five With a main peak molecular weight in the range of preferably 5 × 10 ^Three ~ 5x10 ^Four In the range. Main peak molecular weight is 2 × 10 ^Three If it is lower than that, the charging characteristics may be adversely affected, and when stored at a high temperature, the resin component containing the diene monomer may migrate to the toner surface and adversely affect blocking resistance. Main peak molecular weight is 1 × 10 ^Five If it exceeds 1, the melt viscosity becomes too high, causing problems in fixability, and the flexibility of the resin component containing the diene monomer cannot be effectively expressed, resulting in low temperature offset. End up.
[0151]
In the present invention, the THF soluble content of the toner is a toner component that is soluble in THF. Specifically, the binder resin is a main component, and includes a wax component and the like. The THF soluble content of the toner can be obtained as follows.
[0152]
Put the toner sample in THF and leave it for several hours, then shake it well, mix well with THF (until the sample is no longer united), and let stand for more than 12 hours. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, the THF-soluble matter is passed by passing through a sample processing filter (pore size 0.2 μm, for example, Mysori disk H-25-5: manufactured by Tosoh Corporation, Excrodisk 25CR: manufactured by Gelman Science Japan, etc.). Can be sorted. The concentration of the obtained solution is adjusted so that the binder resin component is 0.5 to 5.0 mg / ml to obtain a GPC sample.
[0153]
In the present invention, the molecular weight distribution of the chromatogram by GPC of the THF soluble part of the toner can be measured under the following conditions.
[0154]
That is, the column is stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min. ) Is injected and measured. In measuring the molecular weight of a toner sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.
[0155]
As standard polystyrene samples for preparing calibration curves, for example, TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, manufactured by Tosoh Corporation Calibration curves can be created using F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500, using at least about 10 standard polystyrene samples Is appropriate.
[0156]
Further, a detector in which an RI (refractive index) detector and a UV (ultraviolet) detector are arranged in series is used. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns, and in the present invention, for example, combinations of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko KK Can be mentioned. A high-speed GPC HPLC8120 GPC manufactured by Tosoh Corporation can be used as the apparatus.
[0157]
Moreover, in this invention, THF insoluble content must be 5-60 mass%. Preferably, it is 5-55 mass%. When the THF-insoluble content is 5% by mass or more, it is considered that the three-dimensionalization in the vicinity of the toner surface by the diene monomer is performed well. If the THF-insoluble content is less than 5% by mass, the three-dimensionalization in the vicinity of the toner surface is insufficient, resulting in poor durability at high temperatures, and the charge stability of the toner is prolonged for a long time. It becomes difficult to hold over. On the other hand, when the THF-insoluble content exceeds 60% by mass, the advantage derived from the flexibility of the binder resin containing the diene monomer is hardly exhibited, so that offset tends to occur during fixing.
[0158]
In the present invention, the THF-insoluble matter can be controlled relatively easily by the diene monomer. That is, if the diene monomer content in the toner is increased, the THF-insoluble content can be increased.
[0159]
However, the THF-insoluble content of the toner of the present invention is not determined only by the amount of the diene monomer, but when the toner is produced by a pulverization method, the amount of the diene monomer contained or the vicinity of the toner particle surface It depends on the amount of polymerization initiator added to react unreacted double bonds. In this case, the influence of the amount of diene monomer tends to be large. In addition, when a toner is produced by suspension polymerization, it is affected by the amount of diene monomer, the amount of polymerization initiator during polymerization reaction or reaction treatment, and the polymerization temperature or temperature during reaction treatment. Changing the amount of the polymerization initiator used will greatly affect the peak molecular weight of the THF-soluble component. Therefore, when adjusting the THF-insoluble component in the present invention, the peak molecular weight of the THF-soluble component is adjusted. You must also consider.
[0160]
In addition, it is possible to obtain the same effect by adding a monomer having two or more polymerizable double bonds.
[0161]
Such monomers include o (m-, p-)-divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol (meth) acrylate, o (m-, p- ) -Divinylcyclohexane, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. These monomers may be used alone or in combination of two or more.
[0162]
In the present invention, the THF-insoluble content of the toner is the mass ratio of the binder resin component that is insoluble in THF in the binder resin composition in the toner particles, and the binder resin composition containing a crosslinking component. It becomes a standard indicating the degree of crosslinking. However, even if the THF-insoluble content is 0% by mass, it does not necessarily mean that it is not crosslinked. In the present invention, the THF-insoluble matter is defined as a value measured as follows.
[0163]
That is, when the toner is a non-magnetic toner, the pigment content and the like are measured in advance by a known method, and when the toner is a magnetic toner, the pigment and magnetic material content and the like are measured in advance. Next, a fixed amount of 0.5 to 1.0 g of toner is weighed (W ₁ g), put into a cylindrical thick paper (No. 86R manufactured by Toyo Noshi Paper), run through a Soxhlet extractor, extract for 20 hours using 100 to 200 ml of THF as a solvent, and evaporate soluble components extracted with the solvent. Vacuum dried at a temperature of several hours and weigh the amount of THF soluble resin component (W ₂ g). Of the pigment and magnetic material contained in the toner in a predetermined amount, the mass of the component soluble in THF is expressed as W. _Three g, the mass of components insoluble in THF is W _Four If g, the THF-insoluble matter in the resin composition can be calculated according to the following formula.
[0164]
[Outside 8]

[0165]
<2> Method for producing dry toner of the present invention
Various methods can be mentioned as a method for producing the toner of the present invention, but it is preferable that a part or the whole is produced by a polymerization method. Part of the toner is produced by a polymerization method after being obtained by polymerizing only the binder resin by applying solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, block copolymerization, grafting, etc. In this method, toner particles are obtained by a pulverization method, a melt spray method, etc., and the entire toner is produced by a polymerization method. A toner is obtained by adding a colorant, a charge control agent, etc. This is a method for simultaneously producing the binder resin and the toner.
[0166]
When the toner of the present invention is produced by a pulverization method, the above-mentioned diene monomer component-containing resin, wax component, colorant (may be a magnetic material), resin used in combination as necessary, charge control agent and other Additives etc. are thoroughly mixed from a mixer such as a Henschel mixer or a ball mill, then melt-kneaded using a heat kneader such as a pressure kneader or extruder, and solidified by mechanical or jet flow after cooling and solidification. Under impact with the target, it is pulverized to a desired toner particle size. Thereafter, toner particles are smoothed and spheroidized as necessary. Next, the particle size distribution is sharpened by a classification process. Further, the toner of the present invention can be obtained by sufficiently mixing the classified powder with an external additive such as silica fine particles by a mixer such as a Henschel mixer. As the production method of the present invention, for example, a spheroidized toner particle is reacted with a polymerization initiator and a resin containing a diene monomer component present on the toner surface with a polymerizable monomer added as necessary. As a result, the strength in the vicinity of the toner particle surface can be increased.
[0167]
The diene monomer component-containing resin constituting the binder resin contained in the toner of the present invention may be contained in the toner in any shape and state, and is compatible with other resins constituting the binder resin. It may be in a state of being separated or phase separated. When the toner is produced by the pulverization method, the diene monomer component-containing resin does not need to be melted together with the other resin in the melt-kneading step, and is dispersed in the melted other resin. Also good. In such a case, the diene monomer component-containing resin in the toner is dispersed in the other resin used together. When diene monomer component-containing resin and other resin are uniformly dissolved and mixed in advance using a solvent such as xylene, the diene monomer component-containing resin is finely dispersed in other resins, or sometimes compatibilized. Is done. Without carrying out such a homogenization operation, when kneading the diene monomer component-containing resin powder and another resin, and kneading below the melting temperature of the diene monomer component-containing resin, Since the diene monomer component-containing resin is dispersed in the toner in a powder state, it is preferable to use a diene monomer component-containing resin finely pulverized to 1 μm or less, preferably 0.5 μm or less.
[0168]
As another method for producing the toner, a diene monomer component-containing resin that has been finely divided into a classified powder obtained in the classification step together with a fluidizing agent or separately is added and mixed sufficiently, and the diene monomer is mixed on the toner particle surface. There is also a method of fixing the monomer component-containing resin. In this case, the resin in the classified powder may contain the diene monomer component-containing resin or may not contain it at all. Further, the toner particles may be smoothed and spheroidized after being fixed. Further, the polymerization initiator and the polymerizable monomer added as necessary are adsorbed on the toner particles after fixing or spheroidizing treatment, and reacted with the diene monomer component-containing resin present on the surface. As a result, the strength in the vicinity of the toner particle surface can be increased.
[0169]
Further, the same effect can be obtained by adsorbing a composition comprising a monomer component having a diene monomer component-containing resin and a polymerization initiator to toner particles that are cores having no diene monomer component-containing resin. It is also possible to obtain.
[0170]
As another method, similarly to the method described in Japanese Examined Patent Publication No. 56-13945, a disk or a multi-fluid nozzle is used to mist the molten mixture containing the diene monomer component-containing resin constituting the binder resin in the air. And a melt spray method for obtaining a spherical toner. Also, polymer particles containing no diene monomer are produced by a polymerization method, and then a resin containing fine diene monomer components is attached to the surface of the polymer particles, and the particles are smoothed as necessary. And a spheroidizing method.
[0171]
In any case, the binder resin can be obtained by polymerizing by applying solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, block copolymerization, grafting and the like.
[0172]
When the entire toner of the present invention is produced by a polymerization method, a diene monomer component-containing resin is dissolved in the monomer composition and described in JP-B-36-10231 and JP-A-59-61842. A method for directly producing a toner using a suspension polymerization method as described above, a dispersion polymerization method for directly producing a toner using an aqueous organic solvent that is soluble in monomers and insoluble in the resulting polymer. Alternatively, the toner of the present invention can be obtained by an emulsion polymerization method represented by a soap-free polymerization method in which a toner is produced by direct polymerization in the presence of a water-soluble polymerization initiator. In addition, a method of providing a surface layer with a diene monomer component-containing resin and a monomer (composition) of another resin on core particles that do not have a diene monomer component-containing resin can be employed, or The toner particles having a diene monomer component-containing resin remain in the toner particles with a polymerization initiator, preferably a highly hydrophilic polymerization initiator, on the surface, or if necessary. It is preferable to add a step for increasing the strength in the vicinity of the toner particle surface by reacting with the added monomer component. In that case, it is also preferable to add a diene monomer component-containing resin and a polymerizable monomer together.
[0173]
Also, under pressure, a polymerizable monomer composition containing a diene monomer component-containing resin, other polymerizable vinyl monomer, wax, and a colorant is subjected to suspension polymerization, emulsion polymerization, or dispersion polymerization. As a result, the toner of the present invention can be obtained.
[0174]
Among the toner production methods described above, the melt spray method tends to broaden the particle size distribution of the obtained toner, and the dispersion polymerization method shows a very sharp particle size distribution, but the range of selection of materials to be used In addition, since an organic solvent is used, the production apparatus is complicated and complicated from the viewpoint of waste solvent treatment and solvent flammability. In addition, the emulsion polymerization method has the advantage that the particle size of the toner is relatively uniform, but generally the particle size of the generated particles is very fine and difficult to use as a toner as it is, and the used water-soluble polymerization is started. The terminal of the agent and the emulsifier may be present on the surface of the toner particle, which may deteriorate the environmental characteristics of the toner.
[0175]
On the other hand, the method of producing the toner particles obtained by the pulverization method by smoothing and spheroidizing, or the production by the suspension polymerization method may keep the circularity of the toner and the standard deviation of the circularity within a desired range. Although it is easy and preferred, in the present invention, production by suspension polymerization is the most preferred production method.
[0176]
Further, the method for producing the toner of the present invention by the suspension polymerization method is particularly easy to control the shape of the toner particles, and a monomer composition using a diene monomer component-containing resin as a raw material for the binder resin. Since it only has to be dissolved in the resin, it is a particularly preferable production method because there are many types of resins that can be used.
[0177]
In the present invention, as described above, various production methods can be used. However, what is important is that after the resin is pulverized in the case of the pulverization method, and at the time of the polymerization conversion rate described later in the case of the polymerization method. This is to react the unreacted double bond of the component contained in the particles, particularly the double bond of the component derived from the diene monomer to form a crosslink on the toner particle surface.
[0178]
In the present invention, the following production method is particularly preferred.
[0179]
Add the diene monomer component-containing resin, colorant, wax, radical polymerization initiator and other additives as necessary to the polymerizable vinyl monomer, and use a homogenizer, ultrasonic disperser, etc. A polymerizable monomer composition is prepared by dissolving or dispersing. The polymerizable monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer using a normal stirrer, homomixer, or homogenizer. Preferably, granulation is performed by adjusting the stirring speed and stirring time so that the droplets of the polymerizable monomer composition have the desired toner particle size. Thereafter, the dispersion stabilizer acts to polymerize the polymerizable vinyl monomer in an aqueous medium to produce toner particles while stirring to such an extent that the particle state is maintained and particle settling is prevented. . A preferred method is to add a radical polymerization initiator to increase the strength in the vicinity of the surface of the toner particles when the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass.
[0180]
In the present invention, examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane- 1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo-based polymerization initiators and diazo-based polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone A radical polymerization initiator such as a peroxide polymerization initiator such as peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide is preferably used. The amount of the polymerization initiator used varies depending on the desired degree of polymerization, but is generally 0.5 to 20% by mass based on the polymerizable monomer. The kind of the polymerization initiator varies slightly depending on the polymerization method, but it is used in one or a combination of two or more selected from the above polymerization initiators with reference to the 10-hour half-life temperature.
[0181]
The polymerization initiator newly added when the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass may be an oil-soluble polymerization initiator as described above. A radical polymerization initiator can also be used.
[0182]
Examples of the water-soluble radical polymerization initiator include polymerization initiators such as sodium persulfate, potassium persulfate, and ammonium persulfate, and one or a combination of two or more thereof can be used. A water-soluble radical polymerization initiator is preferable because it can be easily added during production and can be added in an aqueous solution. Furthermore, a highly water-soluble or highly hydrophilic polymerization initiator is preferable from this point because it efficiently acts on the diene monomer-containing resin present on the surface of the toner particles on the toner particles.
[0183]
Conversely, since an oil-soluble radical polymerization initiator can be added after emulsification or dispersion in water, it is preferable from the viewpoint that the options can be expanded and the reactivity can be controlled. .
[0184]
The amount of the radical polymerization initiator to be newly added varies depending on the target degree of polymerization, but is preferably used in the range of 0.5 to 10% by mass with respect to the polymerizable monomer.
[0185]
Examples of the aqueous medium include water and a water / alcohol mixed solvent, and water is preferably used. In the suspension polymerization method, it is usually preferable to use 100 to 5000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the polymerizable monomer composition.
[0186]
In the toner production method of the present invention, it is preferable to newly add a radical polymerization initiator when the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass. When added to, the conversion rate of the polymerization reaction is very low, so the amount of the polymerization initiator with respect to the polymerizable monomer increases in a state where the particle shape is not stable, and the peak of the obtained binder resin component Since molecular weight may become too low, it is not preferable. More preferably, the timing of newly adding the radical polymerization initiator is when the conversion is in the range of 20 to 95 mass%, particularly 25 to 90 mass%.
[0187]
For example, the conversion of the polymerization reaction can be calculated as follows.
[0188]
A value obtained by quantifying unreacted polymerizable monomer from a calibration curve prepared in advance using a gas chromatograph and defining it as an unconverted rate (%) and subtracting from 100 Is determined as the conversion rate. Specifically, it can be measured by the internal standard method under the following conditions.
[0189]
(Conversion rate:%) = 100− (Unconverted rate determined from calibration curve from amount of unreacted polymerizable monomer)
Sample: A sample (polymerization reaction solution) 5 μl and dimethylformamide 1 μl are placed in a vial and sealed.
Measuring device: HP6890 (manufactured by HP)
Carrier gas: Industrial pure helium
Split (split ratio 100: 1), linear velocity 35cm / sec
Column: HP-INNOWax ID 0.2mm, length 50m, film thickness 0.4μm
Temperature rise: After holding at 40 ° C. for 2 minutes, the temperature is raised to 200 ° C. at a rate of 20 ° C. per minute.
Inlet temperature: 120 ° C
Detector: FlD 220 ℃
[0190]
The present invention relating to a production method is to improve the strength of toner particles by forming a three-dimensional network by reacting a polymerizable double bond of a binder resin containing a diene monomer component-containing resin in the vicinity of the particle surface. When the polymerization conversion rate exceeds 95% by mass when a radical polymerization initiator is newly added, the amount of the remaining polymerizable monomer is very small, and the particles Since the polymerization initiator is newly added in a state in which the resin is almost solidified, the molecular motion in the particles is extremely limited, and the polymerizable double bond of the binder resin including the resin containing the diene monomer component Is not preferable because it tends to be unable to react well. On the other hand, when the polymerization conversion rate does not reach 10% by mass when a radical polymerization initiator is newly added, on the contrary, since free molecular motion is possible, a polymerization initiator is newly added. However, the reaction does not occur so as to form a three-dimensional network on the particle surface.
[0191]
In the present invention, when the 10-hour half-life temperature of the newly added radical polymerization initiator is T1 (° C.) and the reaction system temperature when added is T2 (° C.), 5 ≦ (T2−T1) ≦ It is preferable to satisfy 30 relationships. Satisfying this relationship is preferable because the radical polymerization initiator efficiently participates in the reaction.
[0192]
Further, when the toner is produced by suspension polymerization, the dispersion stabilizer used is an inorganic compound such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, Examples include magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of the organic compound include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, hydroxyethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, and starch. These dispersion stabilizers are preferably used in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer composition.
[0193]
When an inorganic compound is used as the dispersion stabilizer, a commercially available product may be used as it is, but fine particles of the inorganic compound may be generated in a dispersion medium in order to obtain fine particles. For example, tricalcium phosphate can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring.
[0194]
For fine dispersion of these dispersion stabilizers, 0.001 to 0.1 parts by mass of a surfactant may be used in combination. This is to promote the intended action of the dispersion stabilizer, for example, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, lauric acid Anionic surfactants such as sodium, potassium stearate, potassium oleate, nonionic surfactants such as ethylene oxide and / or propylene oxide adducts of alkylphenols, alkylonium salt type cationic surfactants, betaine type And amino acid type amphoteric surfactants.
[0195]
The polymerization reaction time is preferably 2 to 24 hours. If it is less than 2 hours, the desired conversion rate of the polymerizable monomer is not achieved, and there are many unreacted polymerizable monomers, and the removal process becomes complicated. If it exceeds 24 hours, the reaction time is too long and the productivity is high. 2 to 24 hours are preferable.
[0196]
Moreover, what is necessary is just to set superposition | polymerization temperature to the temperature of 40 degreeC or more, generally 50-90 degreeC. The temperature may be raised in the latter half of the polymerization reaction. Further, in order to remove unreacted polymerizable monomers and by-products, the aqueous medium is partially distilled off from the reaction system in the latter half of the reaction or after the completion of the reaction. May be. After completion of the reaction, the produced toner particles are washed, collected by filtration, and dried.
[0197]
In the toner production method of the present invention, a known crosslinking agent, chain transfer agent, polymerization inhibitor, etc. may be further added and used to control the degree of polymerization.
[0198]
In the case of producing a toner by a polymerization method, the particle size distribution control and particle size control of the toner particles are carried out by the type or amount of dispersion stabilizer, mechanical equipment conditions (for example, rotor peripheral speed, number of passes, stirring blade shape, etc. , Container shape) or the solid content concentration in the aqueous medium can be controlled.
[0199]
<3> Image forming method of the present invention
The image forming method of the present invention comprises a charging step of applying a voltage to a charging member to charge the electrostatic latent image carrier; an electrostatic latent image for forming an electrostatic latent image on the charged electrostatic latent image carrier Forming step: Development for forming the toner image on the electrostatic latent image carrier by attaching the toner of the present invention carried on the toner carrier to the electrostatic latent image formed on the electrostatic latent image carrier. A transfer process for transferring a toner image formed on the electrostatic latent image carrier to a transfer material; and a fixing process for fixing the toner image transferred to the transfer material.
[0200]
Next, some embodiments of the image forming method of the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to these.
[0201]
FIG. 5 shows an image forming apparatus performed by a one-component development method.
[0202]
In the image forming method of the present invention, as shown in FIG. 5, the toner carrier and the electrostatic latent image carrier (hereinafter also referred to as “photosensitive drum”) may rotate in opposite directions. (In FIG. 5, the toner carrier 202 rotates in the direction opposite to the arrow C, and the photosensitive drum 209 rotates in the direction of arrow D).
[0203]
It is preferable to set the moving speed of the surface of the toner carrying member in the development region to be 1.05 to 3.0 times the moving speed of the surface of the electrostatic latent image carrying body. By setting the moving speed to be 1.05 to 3.0 times, the toner layer on the toner carrier receives an appropriate stirring effect, so that the faithful reproduction of the electrostatic latent image is better. It becomes.
[0204]
In the development process, when developing the electrostatic latent image on the electrostatic latent image carrier and the toner coated on the toner carrier in a thin layer (hereinafter referred to as “contact development”), in particular. When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the electrostatic latent image carrier, the stirring effect received by the toner on the electrostatic latent image carrier is insufficient, and a good image is obtained. Quality cannot be expected. Also, when developing an image that requires a large amount of toner over a wide area, such as a solid black image, the amount of toner supplied to the electrostatic latent image is insufficient and the image density becomes low. As the peripheral speed ratio increases, the amount of toner supplied to the development site increases. In addition, since the toner is frequently attached to and detached from the latent image, the toner in the unnecessary part (non-image part) is collected and applied to the necessary part (image part). Images can be obtained. Further, as the image forming method of the present invention, it is possible to apply a development and cleaning process, which will be described later, and in the development and cleaning process, when there is a transfer residual toner adhered on the electrostatic latent image carrier. The operation of adjusting the chargeability of the transfer residual toner between the surface of the electrostatic latent image bearing member and the toner by the peripheral speed difference and then recovering by electric field cleaning is important. It is convenient for collecting the transfer residual toner. However, if the peripheral speed ratio exceeds 3.0, on the other hand, in addition to various problems caused by excessive charging of the toner as described above (image density reduction due to excessive charging of the toner, etc.), mechanical It is not preferable because deterioration of toner due to stress and toner adhesion to the toner carrier may occur or be promoted.
[0205]
As the electrostatic latent image carrier in the present invention, a-Se, CdS, ZnO ₂ A photosensitive drum or photosensitive belt having a photoconductive insulating material layer such as OPC or a-Si is preferably used.
[0206]
In addition, an OPC photosensitive member (photosensitive drum or photosensitive belt) having an organic photosensitive layer containing a binder resin such as a polycarbonate resin, a polyester resin, or an acrylic resin also has good transferability and cleaning properties, poor cleaning, and a photosensitive member. This is preferable because toner fusion to the toner and filming of the external additive hardly occur.
[0207]
In the present invention, when the developing process is a non-contact developing method, the surface roughness Ra (μm) of the toner carrier is preferably 0.2 to 1.5. When the surface roughness Ra is 1.5 or less, the toner carrying ability of the toner carrier is suppressed, the toner layer on the toner carrier is thinned, and the toner carrier and the toner are contacted frequently. Therefore, the chargeability of the toner is also improved, and the image quality is synergistically improved.
[0208]
Further, when the development process is a contact development method, the surface shape of the toner carrier is set so that the surface roughness Ra (μm) is 0.2 to 3.0, so that high image quality and high durability are achieved. Is preferable because both can be satisfied. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. If the surface roughness Ra of the toner carrier exceeds 3.0, it may be difficult to reduce the thickness of the toner layer on the toner carrier, and the chargeability of the toner may not be improved. The improvement in image quality cannot be expected. Since the toner carrying capacity on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, if the surface roughness Ra is smaller than 0.2, it may be difficult to control the toner coating amount.
[0209]
To make the surface roughness Ra of the toner carrier into the above range, for example, it is possible to change the polishing state of the surface layer of the toner carrier. That is, if the surface of the toner carrier is roughened, the surface roughness can be increased, and if the surface is finely polished, the surface roughness can be reduced. In the present invention, the surface roughness Ra of the toner carrier is measured using a surface roughness measuring instrument (Surfcoder SE-30H, manufactured by Kosaka Laboratory Co., Ltd.) based on JLS surface roughness “JIS B 0601”. Is the centerline average roughness. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line, the center line of this extraction portion is the X axis, the direction of the vertical magnification is the Y axis, and the roughness curve is When represented by y = f (x), the value obtained by the following formula is represented in micrometers (μm).
[0210]
[Outside 9]

[0211]
As the toner carrier having the above properties, a so-called elastic roller having an elastic layer on the surface is preferably used.
[0212]
As the configuration of the elastic roller, a cored bar is used, and an outer periphery thereof is covered with an elastic layer. Silicone rubber and Teflon rubber are preferably used as the material of the elastic layer.
[0213]
The hardness of the elastic layer used is preferably 20 to 65 degrees in Asker C hardness.
[0214]
The resistance of the toner carrier is 10 in terms of volume resistance. ² -10 ⁹ A range of about Ω · cm is preferable. When there is a pinhole or the like on the surface of the electrostatic latent image carrier, 10 ² If it is lower than Ω · cm, overcurrent may flow. ⁹ When it is higher than Ω · cm, the toner is likely to be charged up by frictional charging, and the image density is likely to be lowered. In order to set the volume resistance value of the elastic layer within the above range, it is possible to adjust the elastic material by blending and dispersing a conductivity-imparting agent such as carbon black and iron oxide.
[0215]
The amount of toner on the toner carrying member is regulated by a regulating member. Examples of the toner regulating member include a regulating member arranged at a predetermined interval from the toner carrying member and an elastic body that is in contact with the toner carrying member. The regulation member which becomes is mentioned.
[0216]
The amount of toner on the toner carrier is 0.1 to 1.5 mg / cm. ² Is preferably 0.2 to 0.9 mg / cm ² Is more preferable. 0.1 mg / cm ² If it is less than 1, it is difficult to obtain a sufficient image density, and 1.5 mg / cm ² If it exceeds the upper limit, it becomes difficult to uniformly triboelectrically charge individual toner particles, which causes fogging.
[0217]
In the present invention, the restricting member disposed at a predetermined interval from the toner carrier may be a metal blade, a doctor blade that is a ferromagnetic metal blade such as a magnetic blade, or a rigid roller using metal, resin, ceramic, or the like. Sleeves may be used, and magnetism generating means may be placed inside them.
[0218]
Further, the regulating member made of an elastic body that is in contact with the toner carrying member is not particularly limited as long as the toner is pressed and applied to make a thin layer. For example, an elastic blade or an elastic roller is used. Although an elastic body is mentioned, the braid | blade consisting of an elastic body is preferable.
[0219]
The contact with the toner carrying member is opposed to, for example, the base which is the upper side portion of the elastic blade is fixed to the toner container, and the variable portion is moved in the forward direction of the toner carrying member against the elasticity of the blade. In this state, the inner surface side of the blade (the outer surface side in the case of the reverse direction) is brought into contact with the surface of the toner carrying member with an appropriate elastic pressure. According to such an apparatus, a stable and dense toner layer is formed on the toner carrying member with less influence due to environmental fluctuations. The reason is not necessarily clear, but because the elastic body forcibly rubs against the surface of the toner carrier, the toner is always charged in the same state regardless of the change in the behavior due to the environmental change of the toner. It is guessed.
[0220]
FIG. 5 shows a developing blade 201 as a regulating member for regulating the toner layer thickness. The developing blade 201 is in contact with the toner carrier 202 through the toner layer. The contact pressure at this time is preferably in the range of 5 to 50 g / cm.
[0221]
If it is less than 5 g / cm, it becomes difficult to control the toner coating amount, and it may be difficult to impart uniform frictional charging to the toner, which causes fogging. On the other hand, if it exceeds 50 g / cm, the toner particles may be subjected to an excessive load, so that the deformation of the particles and the fusion of the toner to the developing blade or the toner carrier are likely to occur.
[0222]
For the elastic regulating member, it is preferable to select a material of a triboelectric charging series suitable for charging the toner to a desired polarity, rubber elastic body such as silicone rubber, urethane rubber, NBR, and synthetic resin elastic body such as polyethylene terephthalate. Body, stainless steel, steel, and metal elastic body such as phosphor bronze. Moreover, those composites may be sufficient.
[0223]
In addition, when durability is required for the elastic regulating member and the toner carrier, it is preferable that the metal elastic body is bonded to the sleeve contact portion of the elastic body so as to hit the resin or rubber, or is coated.
[0224]
Furthermore, an organic substance or an inorganic substance may be added to the elastic regulating member, and it may be melt-mixed or dispersed. For example, the chargeability of the toner can be controlled by adding a metal oxide, metal powder, ceramics, carbon allotrope, whisker, inorganic fiber, dye, pigment, or surfactant. In particular, when the elastic body is a molded body such as rubber or resin, fine particles of metal oxide such as silica, alumina, titania, tin oxide, zirconia and zinc oxide, carbon black, and a charge control agent generally used for toner It is also preferable to contain.
[0225]
Further, a developing blade that is a regulating member that regulates the amount of toner on the toner carrier, a supply roller that is a supply member that supplies toner to the toner carrier, and / or a direct current electric field and / or a brush member due to a loosening action on the toner It is also a preferred configuration to apply an alternating electric field. The unraveling action improves the uniform thin layer coatability and uniform chargeability of the toner carrier, and the toner supply and stripping at the supply site is made smoother, so that a high-quality image with sufficient image density can be obtained. You will be able to get
[0226]
In the developing step of the present invention, the electrostatic latent image carrier and the toner carrier have a certain distance, and it is possible to develop by forming an alternating electric field between them. Specifically, a jumping development method can be mentioned. In the above description, the “certain interval” may be set to be equal to or greater than the thickness of the toner layer on the toner carrier. In order to form an alternating electric field between the electrostatic latent image carrier and the toner carrier, for example, an AC bias can be applied between the two.
[0227]
As the development step in the above contact development method, for example, development can be performed using a development unit having a development device 31 as shown in FIG. Specifically, the toner 34 supplied from the application roller 32 and whose toner layer thickness is regulated by the developing blade 33 as a regulating member while applying a direct current or an alternating current bias to the toner carrier 37 by the power source 36 is transferred to the photosensitive drum 35. Development is performed in a state of being in contact with. As the toner carrier, an elastic roller is preferably used. In the case of using an alternating electric field, a triangular wave, a rectangular wave, a sine wave, a waveform in which the duty ratio (Duty ratio) is changed, or a waveform in which the alternating is periodically turned off can be selected and used. A DC electric field with a small voltage load on the photosensitive drum is preferably used, and the applied bias is a dark portion potential (potential immediately after the charging step) and a bright portion potential (potential of the exposed portion after the exposure step) on the photosensitive drum. It is set to an appropriate value between.
[0228]
As a condition of the development step in the image forming method of the present invention, it is preferable to use the reversal development method in either the jumping development method or the contact development method. Furthermore, it is possible to use a development and cleaning process (also referred to as “cleanerless process”) in which the transfer residual toner remaining on the electrostatic latent image carrier in the transfer process is collected by the toner carrier during the development process. It is preferable because the size can be greatly reduced.
[0229]
That is, in the case of reversal development, this developing and cleaning process includes an electric field for collecting toner from the dark portion potential of the electrostatic latent image carrier due to the developing bias to the toner carrier, and the brightening of the electrostatic latent image carrier from the toner carrier. This is done by the action of an electric field that causes toner to adhere to the partial potential.
[0230]
Not only during development but also after the transfer process and before the development process, a DC or AC bias is applied to the transfer residual toner to control the potential so that the residual toner on the electrostatic latent image carrier can be collected. May be. At this time, the DC bias is located between the light portion potential and the dark portion potential.
[0231]
Further, in the case of the contact development method, in the development and cleaning step, the transfer residual is caused by an electric field acting between the photoreceptor as an electrostatic latent image carrier and the elastic roller facing the photoreceptor surface via the toner. Since the toner is cleaned, the surface of the elastic roller or the vicinity of the surface has a potential, and it is necessary to have an electric field in a narrow gap between the surface of the photosensitive member and the surface of the toner carrying member. Therefore, it is necessary to control the resistance of the elastic rubber of the elastic roller in the middle resistance region to prevent electric conduction with the surface of the photoreceptor, or to provide a thin insulating layer on the surface layer of the conductive roller. Furthermore, a conductive resin sleeve in which the side facing the surface of the photoreceptor is covered with an insulating material on the conductive roller, or a conductive layer is provided on the side not facing the photoreceptor with the insulating sleeve is also possible. Further, a configuration is possible in which a rigid roller is used as the toner carrying member and the photosensitive member is a flexible material such as a belt. The resistance of the roller as a toner carrier is 10 ² -10 ⁹ A range of Ω · cm is preferred.
[0232]
In the image forming method of the present invention, a monochromatic image forming method using a developing and cleaning process will be described with reference to FIG.
[0233]
In FIG. 5, a developing device 200 contains toner 204, contacts a photosensitive member 209, which is an electrostatic latent image carrier, and rotates in the direction of arrow C. The toner amount is controlled and charged. And a coating roller 203 that rotates in the direction of arrow B in order to attach the toner 204 to the toner carrier 202 and to apply charge to the toner by friction with the toner carrier 202. is doing. A developing bias power source 217 is connected to the toner carrier 202. A bias power source 218 is also connected to the application roller 203, and a voltage is set on the negative side of the developing bias when using negatively charged toner, and on the positive side of the developing bias when using positively charged toner. Is done.
[0234]
A transfer bias power source 216 having a polarity opposite to that of the photoconductor 209 is connected to the transfer device 206. Here, the length in the rotation direction at the contact portion between the photosensitive member 209 and the toner carrier 202, that is, the so-called developing contact width is preferably 0.2 to 8.0 mm. If the thickness is less than 0.2 mm, the development amount is insufficient and a satisfactory image density cannot be obtained, and the transfer residual toner may not be collected sufficiently. If it exceeds 8.0 mm, the amount of toner supplied becomes excessive, fogging is likely to occur, and the wear of the photoreceptor may be adversely affected.
[0235]
A charging roller 210 as a primary charging member directly contacts the photoconductor 209 and performs charging. A bias power source 215 is connected to the primary charging member 210 so as to uniformly charge the surface of the photoconductor 209. The primary charging member 210 used here is a charging roller that basically includes a central cored bar 210b and a conductive elastic layer 210a that forms the outer periphery thereof. The charging roller 210 is brought into contact with the surface of the photosensitive member 209 with a pressing force, and is driven to rotate as the photosensitive member 209 rotates (the charging roller 210 rotates in the direction of arrow A).
[0236]
As a preferable process condition when using the charging roller, the contact pressure of the roller is 5 to 500 g / cm, and the applied bias is a DC bias or a DC bias superimposed with an AC bias, and is not particularly limited. However, in the present invention, an applied bias of only a DC bias is preferably used, and the bias value in this case is used in the range of 0.2 to 5.0 kV in absolute value.
[0237]
In the image forming apparatus of the present invention, various charging methods can be used. As described above, the charging member and the electrostatic latent image carrier are brought into contact with each other to charge the electrostatic latent image carrier. A charging method is preferably used. When the contact charging method is used, if a large amount of transfer residual toner is present, the toner adheres to the charging member. As a result, charging failure may occur and charging unevenness may occur on the image. That is, when charging is performed by the contact charging method, it is necessary to suppress the transfer residual toner amount to a smaller amount than when charging is performed by corona discharge that does not contact the electrostatic latent image carrier. For these reasons, it is preferable to use the toner of the present invention in which the average circularity and the circularity standard deviation are strictly defined in the contact charging method.
[0238]
Other charging members in the contact charging method include a method using a charging blade and a method using a conductive brush. Charging in these contact charging methods is preferable because high voltage is not required and generation of ozone can be suppressed as compared with non-contact corona charging. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride) can be applied.
[0239]
Following the primary charging step, an electrostatic latent image corresponding to the information signal is formed on the photoconductor 209 by exposure 211 from the light emitting element, and the electrostatic latent image is developed with toner at a position where it abuts the toner carrier 202. Form an image. Furthermore, the image forming method of the present invention can perform suitable development when developing a digital latent image. Next, the toner image is transferred onto the transfer material 205 by the transfer device 206. As described above, in the image forming method of the present invention, it is preferable that the photoconductor 209 and the transfer device 206 are in contact with each other via the transfer material 205.
[0240]
Further, the transfer toner 212 on the transfer material 205 passes through a fixing device having a heating roller 208 as a heating member and a pressure roller 207 as a pressure member, and is fixed on the transfer material to obtain a permanent image.
[0241]
The fixing step is not particularly limited, but in the present invention, a fixing step using a heat fixing device is preferable, and further, the fixing roller is passed between the heating roller as described above and a pressure roller opposed to the heating roller. The step of fixing by heating and pressing is more preferable.
[0242]
Examples of the heating roller include those having a heating element such as a halogen heater incorporated therein, and examples of the pressure roller include those made of an elastic body.
[0243]
As the heat and pressure fixing means, in addition to the above-described heat roller method having a heat roller and a pressure roller as a basic configuration, a method of heat fixing with a heater via a film is also suitable for the toner of the present invention. It can be used from showing matching. Specifically, as shown in FIGS. 3 and 4, the film end regulating flange 25 supports the left and right ends of the fixing film 22. The stay 20 is disposed in the cylindrical fixing film 22, and is integrated with the power supply connector 26 and the power disconnecting member 27 to equip the heating body 21 to constitute a fixing heating unit. The film end regulating flange 25 applies a pressing force to the stay 20 by contracting the coil spring 24 with a spring receiving member (not shown). As a result, a fixing nip portion having a predetermined width is formed between the lower surface of the fixing film 22 and the upper surface of the pressure roller 23. The heating element 21 includes a heater substrate 21a, a heating element 21b, a surface protective layer 21c, and a temperature detecting element 21d. The pressure roller 23 is a sponge pressure roller having a foam such as silicone rubber in the lower layer. For the fixing film 22, it is preferable to use a heat resistant film on the contact surface with the transfer material. As the heat-resistant film, a film having a thickness having a low-resistance release layer in which a conductive material is specifically dispersed in a resin such as PTFE can be used.
[0244]
For example, the surface temperature of the temperature measuring element 21d of the heating body 21 is set to 180 ° C., the total pressure between the heating body 21 and the sponge pressure roller 23 having a silicone rubber foam as a lower layer is 6 kg, and the pressure roller The nip between the fixing film 22 and the fixing film 22 is 8 mm. As the fixing film 22, a heat-resistant polyimide film having a thickness of 60 μm having a low-resistance release layer in which a conductive material is dispersed in PTFE (high molecular weight type) on the contact surface with the transfer material can be used.
[0245]
On the other hand, the untransferred toner 213 remaining on the photosensitive member 209 without being transferred passes between the photosensitive member 209 and the charging roller 210 and reaches the developing contact portion again, and the toner carrying member is subjected to the developing and cleaning process. It is collected in the developing device 200 via 202. As described above, the untransferred toner on the photoconductor after the transfer is collected by the development and cleaning process. The toner collected at this time is collected by the developing device and used again for development.
[0246]
The image forming method of the present invention may be a full-color image forming method using an intermediate transfer method, and the contact development method described above can be preferably used.
[0247]
FIG. 2 is an example of a color image forming apparatus (copier or laser beam printer) using an intermediate transfer belt as an intermediate transfer member. The toner used in the image forming method of the present invention is the toner of the present invention described above. Other than the use of the intermediate transfer belt, other image forming methods using the same image forming apparatus as described above can be used.
[0248]
A photosensitive drum 101, which is a drum-shaped electrophotographic photosensitive member serving as a first electrostatic latent image carrier, is rotationally driven in the X direction indicated by an arrow at a predetermined peripheral speed (process speed). The photosensitive drum 101 is uniformly charged to a predetermined polarity potential by the primary charger 102 during the rotation process, and then subjected to exposure 103 by an image exposure means (not shown). In this way, an electrostatic latent image corresponding to the first color component image (for example, yellow color component image) of the target color image is formed.
[0249]
Next, the electrostatic latent image is developed into a yellow component image which is the first color by the first developing device (yellow color developing device 141). At this time, the second to fourth developing units, that is, the magenta developing unit 142, the cyan developing unit 143, and the black developing unit 144 are not operated and do not act on the photosensitive drum 101. The yellow component image of the color is not affected by the second to fourth developing units.
[0250]
The intermediate transfer belt 120 is driven to rotate in the direction of arrow W at the same peripheral speed as that of the photosensitive drum 101.
[0251]
In the process in which the yellow component image of the first color formed on the photosensitive drum 101 passes through the contact portion between the photosensitive drum 101 and the intermediate transfer belt 120, an intermediate is applied from the bias power source 129 via the primary transfer roller 162. Transfer (primary transfer) is performed on the outer peripheral surface of the intermediate transfer belt 120 by an electric field formed by the primary transfer bias applied to the transfer belt 120.
[0252]
The surface of the photosensitive drum 101 after the transfer of the first color yellow toner image corresponding to the intermediate transfer belt 120 is cleaned by the cleaning device 113.
[0253]
Thereafter, similarly, a second color magenta toner image, a third color cyan toner image, and a fourth color black toner image are formed and sequentially transferred onto the intermediate transfer belt 120 to correspond to the target color image. A synthesized color toner image is formed.
[0254]
The secondary transfer roller 163 is supported in parallel with the secondary transfer counter roller 164 so as to be separated from the lower surface portion of the intermediate transfer belt 120.
[0255]
A primary transfer bias for transferring the toner image from the photosensitive drum 101 to the intermediate transfer belt 120 is applied from a bias power source 129 with a polarity opposite to that of the toner. The applied voltage is, for example, in the range of +100 V to +2 kV.
[0256]
When the first to third color toner images are primarily transferred from the photosensitive drum 101 to the intermediate transfer belt 120, the secondary transfer roller 163 can be separated from the intermediate transfer belt 120. As shown in FIG. 2B, when the transfer residual toner charging member 152 is provided, it is also separated from the intermediate transfer belt 120. A voltage is applied from the bias power supply 126 to the transfer residual toner charging member.
[0257]
Through the guide 110, the transfer material P, which is the second image carrier, is fed from the paper feed roller 111 to the contact portion between the intermediate transfer belt 120 and the secondary transfer roller 163 at a predetermined timing. The secondary transfer bias is applied to the secondary transfer roller 163 by the bias power supply 128, so that the full-color image transferred onto the intermediate transfer belt 120 is secondarily transferred to the transfer material P. The transfer material P onto which the toner image has been transferred is introduced into the fixing device 115 and fixed by heating.
[0258]
After the image transfer to the transfer material P is completed, the transfer residual toner cleaning device 150 is brought into contact with the intermediate transfer belt 120 to clean the surface of the intermediate transfer belt 120.
[0259]
Further, an intermediate transfer drum can also be used as an intermediate transfer body in place of the intermediate transfer belt. One example is described below.
[0260]
The intermediate transfer drum is composed of a pipe-shaped conductive core and an intermediate resistance elastic layer formed on the outer peripheral surface thereof. The core metal may be a plastic pipe with conductive plating.
[0261]
Medium resistance elastic layers include silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber, EPDM (ethylene-propylene-diene terpolymer), carbon black, zinc oxide, tin oxide, Mixing and dispersing a conductivity-imparting agent such as silicon carbide, the electrical resistance value (volume resistance) is 10 ^Five -10 ¹¹ A solid or foamed layer adjusted to a medium resistance of about Ω · cm is preferably used.
[0262]
The intermediate transfer drum is disposed in parallel with the electrostatic latent image carrier and is in contact with the lower surface portion of the electrostatic latent image carrier. It rotates in the same direction as the electrostatic latent image carrier or in the opposite direction.
[0263]
A transfer device is disposed in parallel with the intermediate transfer drum and brought into contact with the lower surface portion of the intermediate transfer drum. The transfer device is, for example, a transfer roller or a transfer belt, and the contact portion at the same peripheral speed as the intermediate transfer drum. In the same direction.
[0264]
The transfer device is disposed so as to be in direct contact with the intermediate transfer drum. In the case of a transfer roller, the transfer device has a basic configuration of a central cored bar and a conductive elastic layer forming the outer periphery thereof.
[0265]
Common materials can be used for the intermediate transfer drum and the transfer roller. By setting the volume resistivity of the elastic layer of the intermediate transfer drum to a smaller value, the voltage applied to the transfer roller can be reduced, a good toner image can be formed on the transfer material, and the transfer material can be wrapped around the intermediate transfer drum. Can be prevented. In particular, the volume resistance value of the elastic layer of the intermediate transfer drum is particularly preferably 10 times or more the volume resistance value of the elastic layer of the transfer roller.
[0266]
For example, the conductive elastic layer of the transfer roller has a volume resistance value of 10 such as polyurethane in which a conductive material such as carbon is dispersed and ethylene-propylene-diene terpolymer (EPDM). ⁶ -10 ^Ten Made of an elastic body of about Ω · cm. A bias is applied to the core of the transfer roller by a low voltage power source, and the bias condition is preferably 0.2 to 10 kV in absolute value.
[0267]
In the above description, an image forming method by a one-component developing method having a developing and cleaning process, or an intermediate transfer type image forming method using an image forming apparatus having an intermediate transfer belt and an intermediate transfer drum has been described. The toner can be suitably used in image forming methods other than those described above.
[0268]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
[0269]
All parts in the following formulations are parts by mass.
[0270]
<1> Production of diene monomer component-containing resin
Diene monomer component-containing resins 1 to 10 were produced as follows.
[0271]
<Production of diene monomer component-containing resin 1>
80 parts by mass of styrene, 1 part by mass of 2,2′-azobisisobutyronitrile and 500 parts by mass of benzene are added to a reaction vessel capable of depressurization, and 20 parts by mass of 1,3-butadiene is passed through a liquefaction meter. The mixture was charged by distillation and then degassed under reduced pressure until dissolved air bubbles disappeared and sealed in a vacuum. This was polymerized while shaking in a constant temperature bath at 60 ° C. After completion of the polymerization, the sealed tube was opened and the contents were poured into methanol for reprecipitation. The supernatant was decanted, and the precipitate was washed with methanol, and then dried under reduced pressure at 40 ° C. and 200 Pa (1.5 mmHg) for 24 hours to obtain a styrene-butadiene copolymer (diene monomer component-containing resin 1). . The composition ratio of this polymer was determined as follows. As a result, the mass ratio of styrene / butadiene was 80/20. The mixing ratio of the raw materials is shown in Table 2, and the characteristic values are shown in Table 3.
[0272]
Measurement of the content of components derived from diene monomers ¹ This was carried out using 1 H-NMR as follows.
[0273]
Weighed 50-100 mg of a sufficiently washed and dried polymer, dissolved in 1.0 ml of deuterated solvent containing 1% by volume of tetramethylsilane overnight, and after removing insolubles with a membrane filter as necessary, It put into the sample tube of diameter 10mm, and measured using FT-NMR apparatus JNM-EX400 (made by JEOL Ltd.).
[0274]
[Table 2]

[0275]
[Table 3]

<Production of diene monomer component-containing resin 2>
A diene monomer component-containing resin 2 was obtained in the same manner as in the production of the diene monomer component-containing resin 1 except that the type and amount of the monomer used were changed as shown in Table 2. The characteristic values are shown in Table 3.
[0276]
<Production of diene monomer component-containing resin 3>
In a pressure bottle equipped with a septum cap, 126 parts by mass of water, 3.3 parts by mass of disproportionated potassium rosinate, 0.07 parts by mass of sodium salt of naphthalenesulfonic acid-formalin condensate, 0.07 parts by mass of tetraethylenepentamine , 50 parts by mass of styrene, 0.17 parts by mass of third dodecyl mercaptan, and 9 parts by mass of isoprene using a liquefaction meter, and 2 parts by mass of isoprene were vaporized to expel the internal air and plug it. . After attaching to a rotating plate of a rotating polymerization phase at 5 ° C. and stirring for 30 minutes, a solution of cumene hydroperoxide 0.1 part by mass and styrene 3.5 parts by mass was injected using a syringe to initiate polymerization. After 72 hours, 3.5 parts by mass of a 10% aqueous solution of sodium dimethyldithiocarbamate was injected to terminate the polymerization, and steam was blown to drive off unreacted monomers. After adding phenyl-6-naphthylamine corresponding to 2% of the copolymer, the copolymer is coagulated by pouring 25% brine and then 1% sulfuric acid, washed with water, and dried to contain a diene monomer component-containing resin. 3 was obtained. The characteristic values are shown in Table 3.
[0277]
<Production of diene monomer component-containing resin 4>
A diene monomer component-containing resin 4 was obtained in the same manner as in the production of the diene monomer component-containing resin 3 except that the types and amounts of the monomers used were changed as shown in Table 2. The characteristic values are shown in Table 3.
[0278]
<Production of diene monomer component-containing resin 5>
85 parts by mass of styrene, 15 parts by mass of butadiene, 5 parts by mass of sodium fatty acid, and 200 parts by mass of ion-exchanged water were mixed and put into an autoclave that is a polymerization vessel. Next, 3.5 parts by mass of n-dodecyl mercaptan and 0.2 parts by mass of potassium persulfate were added, and emulsion polymerization was performed at 50 ° C. for 15 hours to obtain a diene monomer component-containing resin 5. The characteristic values are shown in Table 3.
[0279]
<Production of diene monomer component-containing resin 6>
Into a 30 l autoclave, 114 parts by mass of benzyl sodium, 368 parts by mass of toluene, 9900 parts by mass of n-hexane were charged in a nitrogen stream, and the temperature was adjusted to 30 ° C. Then, while dropping 8185 parts by mass of butadiene at 30 ° C. The polymerization was stopped by adding 200 parts by mass of methanol. Next, 1000 parts by mass of clay was added and stirred vigorously, followed by filtration to obtain a transparent polymer solution containing no alkali. Next, unreacted butadiene, toluene and n-hexane were distilled off from this polymer solution to synthesize a diene monomer component-containing resin 6 having a number average molecular weight of 1900. The characteristic values are shown in Table 4.
[0280]
[Table 4]

<Production of diene monomer component-containing resin 7>
1000 parts by mass of diene monomer component-containing resin 6, 150 parts by mass of maleic anhydride, 300 parts by mass of xylene, and 2 parts by mass of Antigen 3C (Sumitomo Chemical brand name) were charged into a 2 l autoclave and 8 at 190 ° C. under a nitrogen stream. Reacted for hours. Next, unreacted maleic anhydride and xylene were distilled off under reduced pressure to synthesize maleated polybutadiene having a number average molecular weight of 2000 (diene monomer component-containing resin 7).
[0281]
The structure of the acid group in the maleated polybutadiene (A) ′ is mostly represented by the following (IV).
[0282]
[Outside 10]

[0283]
Moreover, the thing of the structure of following formula (V) hydrolyzed by the water contained in the air or a solvent in part is also contained.
[0284]
[Outside 11]

[0285]
The characteristic values of the diene monomer component-containing resin 7 are shown in Table 4.
[0286]
<Production of diene monomer component-containing resin 8>
In the production example of the diene monomer component-containing resin 6, the diene monomer component-containing resin 8 was prepared in the same manner as the production of the diene monomer component-containing resin 6 except that the raw material butadiene used was changed to 6500 parts by mass of isoprene. Obtained. The characteristic values are shown in Table 4.
[0287]
<Production of diene monomer component-containing resin 9>
Condenser, peracetic acid charging port, N ₂ 400 parts by mass of an ethyl acetate solution having a solid content of 46.3% of diene monomer component-containing resin 8 was charged into a jacketed 2 l reactor equipped with an introduction tube. Next, 0.2 parts by mass of sodium 2-ethylhexyltripolyphosphate was added to 280 parts by mass of peracetic acid (30%, ethyl acetate solution) and dissolved. Thereafter, the peracetic acid solution was added dropwise in about 4 hours while maintaining the reaction temperature at 50 ° C. Thereafter, the temperature was kept at 50 ° C. for 6 hours.
[0288]
Next, 680 parts by mass of purified water was added, and the mixture was stirred for 30 minutes and allowed to stand at 50 ° C. After 30 minutes, the separated aqueous phase was gradually removed. Next, 300 parts by mass of ethyl acetate was added, and further 800 parts by mass of purified water was added and stirred for 30 minutes. Then, the mixture was allowed to stand for 30 minutes while maintaining at 50 ° C., and the aqueous phase was extracted. Furthermore, 700 parts by mass of purified water was added and stirred at 50 ° C. for 30 minutes. Next, the mixture was allowed to stand at 50 ° C. for 30 minutes, and the aqueous phase was extracted to obtain 650 parts by mass of an ethyl acetate solution having a solid content of 30.1%.
[0289]
Subsequently, the obtained upper layer liquid was charged into a thin film evaporator under the conditions of 50 ° C., 2700 to 6700 Pa (20 to 50 mmHg) and 300 ml / h, and a diene monomer component-containing resin 9 having a target epoxy group was obtained. 180 parts by mass were obtained. The characteristic values are shown in Table 4.
[0290]
<Production of diene monomer component-containing resin 10>
Condenser, N ₂ 150 parts by mass of glycidyl methacrylate is added to 1150 parts by mass of the synthesized diene monomer component-containing resin 7 in a jacketed 2 liter reactor equipped with an introduction tube, and the reaction is carried out for 12 hours by heating to 60 ° C. in a reaction vessel. As a result, 1300 parts by mass of the diene monomer component-containing resin 10 was obtained. The characteristic values are shown in Table 4.
[0291]
<2> Manufacture of resins used in combination with diene monomer component-containing resins
Resins 1 and 2 were produced as follows.
[0292]
<Manufacture of resin 1>
In a separable flask made of glass equipped with a thermometer, a stainless stir bar, a flow-down condenser, and a nitrogen introduction tube, 200 parts by mass of xylene was placed and heated to the reflux temperature. A solution mixture of 80 parts by mass of styrene, 20 parts by mass of acrylate-n-butyl and 2.3 parts by mass of di-tert-butyl peroxide was added dropwise thereto, and the solution polymerization was completed in 7 hours under reflux of xylene. A molecular weight resin solution was obtained.
[0293]
On the other hand, 65 parts by mass of styrene, 25 parts by weight of butyl acrylate, 10 parts by mass of monobutyl maleate, 0.2 parts by mass of polyvinyl alcohol, 200 parts by mass of deaerated water, and 0.5 parts by mass of benzoyl peroxide were mixed, suspended and dispersed. . The suspension dispersion was heated and maintained at 85 ° C. for 24 hours under a nitrogen atmosphere to complete the polymerization, thereby obtaining a high molecular weight resin.
[0294]
30 parts by weight of the above high molecular weight resin is put into a low molecular weight resin solution containing 70 parts by weight of the low molecular weight resin, completely dissolved in a solvent and mixed, and then the solvent is distilled off to obtain Resin 1 Obtained.
[0295]
When the above resin 1 was analyzed, the low molecular weight side peak molecular weight was 10,000, the high molecular weight side peak molecular weight was 560,000, the weight average molecular weight (Mw) was 300,000, and the number average molecular weight (Mn) was 55,000. . The glass transition temperature was 55 ° C.
[0296]
<Manufacture of resin 2>
In the same manner as in the production of Resin 1, a low molecular weight resin solution was obtained.
[0297]
On the other hand, 75 parts by mass of styrene, 25 parts by weight of butyl acrylate, 0.2 parts by mass of polyvinyl alcohol, 200 parts by mass of deaerated water, and 0.5 parts by mass of benzoyl peroxide were mixed, suspended and dispersed. The suspension dispersion was heated and maintained at 85 ° C. for 24 hours under a nitrogen atmosphere to complete the polymerization, thereby obtaining a high molecular weight resin.
[0298]
30 parts by weight of the above high molecular weight resin is put into a low molecular weight resin solution containing 70 parts by weight of the low molecular weight resin, completely dissolved in a solvent and mixed, and then the solvent is distilled off to obtain Resin 2 Obtained.
[0299]
When the above resin 2 was analyzed, the low molecular weight side peak molecular weight was 12,000, the high molecular weight side peak molecular weight was 580,000, the weight average molecular weight (Mw) was 300,000, and the number average molecular weight (Mn) was 55,000. there were. The glass transition temperature was 55 ° C.
[0300]
<3> Toner production
As described below, toners 1 to 12 of the present invention and comparative toners 1 to 6 were manufactured as comparative toners.
[0301]
<Manufacture of toner 1>
・ Resin 1 100 parts by mass
・ Diene monomer component-containing resin 1 10 parts by mass
・ Carbon black (BET specific surface area = 90m ² / G) 10 parts by mass
-Negative charge control agent (compound (II)) 2 parts by mass
・ Low molecular weight polyethylene (maximum value of endothermic peak = 115 ° C.) 5 parts by mass
The above materials were mixed with a blender, melted and kneaded with a biaxial extruder heated to 160 ° C., the cooled kneaded product was coarsely pulverized with a hammer mill, and the coarsely pulverized product was finely pulverized with a jet mill.
[0302]
Next, using a device that rotates the rotor to give a mechanical impact, surface modification treatment was performed, and the obtained particles were classified to obtain classified powder 1. On the other hand, 650 parts by mass of ion-exchanged water and 0.1 mol / l-Na in a 2 l four-necked flask equipped with a high-speed stirring device TK type homomixer (manufactured by Koki Kogyo Co., Ltd.) _Three PO _Four 500 parts by mass of the aqueous solution was added, the rotation speed was adjusted to 12000 rpm, and the mixture was heated to 70 ° C. Here 1.0 mol / l-CaCl ₂ 80 parts by mass of an aqueous solution was added to prepare an aqueous dispersion medium containing a minute hardly water-soluble dispersion stabilizer (calcium phosphate salt). 127 parts by mass of the above classified powder 1 are gradually added to an aqueous dispersion medium containing a dispersion stabilizer, heated to 60 ° C. and maintained at the same temperature, and t-butyl peroxyneodecanoate 0. A dispersion obtained by ultrasonically dispersing 7 parts by mass in 0.01 parts by mass of sodium dodecylbenzenesulfonate and 20 parts by mass of ion-exchanged water was added over 5 minutes, and then the reaction was carried out by maintaining at the same temperature for 5 hours. . After completion of the reaction, the suspension was cooled, and then diluted hydrochloric acid was added to remove the dispersion stabilizer. Further, water washing was repeated several times, followed by drying to obtain reaction treated particles A.
[0303]
Hydrophobic silica fine powder (BET specific surface area 240 m) treated with 100 parts by mass of the above reaction-treated particles A and silicone oil ² / G) Toner 1 of the present invention was obtained by dry mixing 1.2 parts by mass with a Henschel mixer.
[0304]
Toner 1 has an average circularity of 0.953, a circularity standard deviation of 0.039, a circle-equivalent number average diameter D1 of 5.3 μm, a high molecular weight side peak molecular weight of 580,000, and a low molecular weight side peak molecular weight of 11,000. Met.
[0305]
<Manufacture of toner 2>
A toner 2 was obtained in the same manner as in the production of the toner 1 except that the kind and the addition amount of the binder resin were changed. Table 5 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0306]
[Table 5]

[0307]
<Manufacture of toner 3>
650 parts by mass of ion-exchanged water and 0.1 mol / l-Na in a 2 l four-necked flask equipped with a high-speed stirring device TK type homomixer (made by Tokushu Kika Kogyo Co., Ltd.) _Three PO _Four 500 parts by mass of the aqueous solution was added, the rotation speed was adjusted to 12000 rpm, and the mixture was heated to 70 ° C. Here 1.0 mol / l-CaCl ₂ 80 parts by mass of an aqueous solution was added to prepare an aqueous dispersion medium containing a minute hardly water-soluble dispersion stabilizer (calcium phosphate salt).
[0308]
On the other hand, as dispersoid,
・ 82 parts by mass of styrene
・ 18 parts by mass of 2-ethylhexyl acrylate
・ Carbon black (BET specific surface area = 90m ² / G) 10 parts by mass
・ Diene monomer component-containing resin 1 10 parts by mass
・ Wax (ester wax, maximum value of endothermic peak = 76 ° C.) 7 parts by mass
・ 2 parts by mass of negative charge control agent (compound (II))
The above mixture was dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.), and 3 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to prepare a polymerizable monomer composition. did.
[0309]
Next, the polymerizable monomer composition is charged into the aqueous dispersion medium, and stirred for 10 minutes while maintaining the rotation speed of a high-speed stirrer at 12000 rpm in a nitrogen atmosphere with an internal temperature of 70 ° C. The reactive monomer composition was granulated. Then, when the stirrer is changed to a propeller stirring blade and held at the same temperature for 2 hours while stirring at 50 rpm, a solution obtained by dissolving 0.4 parts by mass of potassium persulfate in 20 parts by mass of ion-exchanged water is taken over 5 minutes. Further, the polymerization was completed by maintaining at the same temperature for 8 hours. The conversion rate of the polymerization reaction when potassium persulfate was added was 43%.
[0310]
After completion of the polymerization, the suspension was cooled, and then diluted hydrochloric acid was added to remove the dispersion stabilizer. Further, washing with water was repeated several times, followed by drying to obtain polymer particles 3. The polymer particle 3 had a mass average diameter of 6.8 μm.
[0311]
Hydrophobic silica fine powder (BET specific surface area 240 m) treated with 100 parts by mass of the above polymer particles 3 and silicone oil ² / G) Toner 3 of the present invention was obtained by dry mixing 1.5 parts by mass with a Henschel mixer.
[0312]
Toner 3 had an average circularity of 0.989, a circularity standard deviation of 0.021, a circle-equivalent number average diameter D1 of 5.5 μm, and a peak molecular weight of 26,000.
[0313]
<Manufacture of toners 4 to 10>
Toners 4 to 10 were obtained in the same manner as in the production of toner 3 except that the kind of binder resin, the amount added, and the reaction temperature during the reaction treatment were changed. Table 6 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0314]
[Table 6]

[0315]
<Production of Toners 11 and 12>
Ion exchange of organic peroxides in the table with 0.01 parts by mass of sodium dodecylbenzenesulfonate at the polymerization conversion shown in Table 6 by changing the type, amount of binder resin, and reaction temperature during the reaction treatment Toners 11 and 12 were obtained in the same manner as in the production of Toner 3 except that a dispersion liquid ultrasonically dispersed in water was added over 5 minutes. Table 6 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0316]
<Manufacture of Comparative Toner 1>
A comparative toner 1 was obtained in the same manner as in the production of the toner 1 except that the kind of raw material and the amount added were changed. Table 5 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0317]
<Production of Comparative Toner 2>
A comparative toner 2 was obtained in the same manner as in the production of the toner 1 except that the kind of raw material and the amount added were changed and the reaction treatment with the initiator was not performed. Table 5 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0318]
<Manufacture of comparative toners 3-6>
Comparative toners 3 to 6 were obtained in the same manner as the toner 3 except that the type and amount of the binder resin were changed. Table 7 shows the types and amounts of materials used, and Table 8 shows the results of toner analysis.
[0319]
<Manufacture of comparative toner 7>
650 parts by mass of ion-exchanged water and 0.1 mol / l-Na in a 2 l four-necked flask equipped with a high-speed stirring device TK type homomixer (made by Tokushu Kika Kogyo Co., Ltd.) _Three PO _Four 500 parts by mass of the aqueous solution was added, the rotation speed was adjusted to 12000 rpm, and the mixture was heated to 70 ° C. Here 1.0 mol / l-CaCl ₂ 80 parts by mass of an aqueous solution was added to prepare an aqueous dispersion medium containing a minute hardly water-soluble dispersion stabilizer (calcium phosphate salt).
[0320]
On the other hand, as dispersoid,
・ 82 parts by mass of styrene
・ 18 parts by mass of 2-ethylhexyl acrylate
・ Carbon black (BET specific surface area = 90m ² / G) 10 parts by mass
・ Unsaturated polyester 10 parts by weight
・ Wax (ester wax, maximum value of endothermic peak = 76 ° C.) 7 parts by mass
・ 2 parts by mass of negative charge control agent (compound (II))
The above mixture was dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.), and 3 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to prepare a polymerizable monomer composition. did.
[0321]
Next, the polymerizable monomer composition is charged into the aqueous dispersion medium, and stirred for 10 minutes while maintaining the rotation speed of a high-speed stirrer at 12000 rpm in a nitrogen atmosphere with an internal temperature of 70 ° C. The reactive monomer composition was granulated. Then, when the agitator was changed to a propeller stirring blade and held at the same temperature for 2 hours while stirring at 50 rpm, 8.2 parts by mass of styrene monomer, 1.8 parts by mass of n-butyl acrylate, 2.5 parts by mass of unsaturated polyester Polymeric monomer composition prepared by dissolving and dispersing 0.4 parts by weight of potassium persulfate in 40 parts by weight of ion-exchanged water is added over 60 minutes, and the polymerization is completed by holding at the same temperature for 8 hours. did. The conversion rate of the polymerization reaction at the time when the polymerizable monomer composition was added was 60%.
[0322]
After completion of the polymerization, the suspension was cooled, and then diluted hydrochloric acid was added to remove the dispersion stabilizer. Further, water washing was repeated several times, followed by drying to obtain polymer particles 7. The comparative polymer particle 7 had a mass average diameter of 7.0 μm.
[0323]
Hydrophobic silica fine powder (BET specific surface area 240 m) treated with 100 parts by mass of the polymer particles 7 and silicone oil ² / G) 1.5 parts by mass were dry-mixed with a Henschel mixer to obtain a comparative toner 7.
[0324]
Comparative toner 7 had an average circularity of 0.975, a circularity standard deviation of 0.031, a circle-equivalent number average diameter D1 of 5.8 μm, and a peak molecular weight of 30,000. Table 8 shows the analysis results of the toner.
[0325]
[Table 7]

[0326]
[Table 8]

[0327]
<Example 1>
The toners 1 to 12 of the present invention and the comparative toners 1 to 7 obtained as described above were evaluated as follows.
[0328]
First, the image forming apparatus used in this embodiment will be described. In this example, a commercially available laser beam printer LBP-PX (manufactured by Canon) was used for modification for non-magnetic one-component development. The image forming apparatus will be described with reference to FIG.
[0329]
In this embodiment, a reversal developing apparatus for developing a negative (negative polarity) latent image on a photosensitive member using a negative (negative polarity) toner is used.
[0330]
FIG. 1 is a schematic explanatory view of a cross section of a laser beam printer applied to the present invention. The OPC photosensitive drum 10 (diameter 24 mm) rotates in the direction of the arrow and is uniformly charged by the charging roll 11 so that the dark portion potential (Vd) becomes −600V. Next, the exposure device 14 exposes the image portion to form an electrostatic latent image having a bright portion potential (Vl) of −150V. The toner layer on the toner carrier 17 having the toner application roller 16 and the photosensitive drum 10 are not brought into contact with each other and set with an interval of 300 μm, an AC bias (f = 1800 Hz, Vpp = 1400 V), and a DC bias (Vdc = − 400 V) is applied to the toner carrier 17 by the bias applying means V, and the image portion is developed with the negative toner T to form a toner image on the photosensitive drum 10.
[0331]
The obtained toner image is transferred onto the transfer material P by the transfer roll 19, and the toner remaining on the surface of the photosensitive drum 10 is cleaned by the cleaner 13. On the other hand, the transfer material P separated from the photosensitive drum 10 is heated and fixed by the heat fixing device H in order to fix the toner image on the transfer material P. The above process is repeated to form an image. At this time, the heat fixing device H described in FIGS. 3 and 4 is used, the surface temperature of the temperature detecting element 21d of the heating body 21 is 190 ° C., and the total pressure between the heating body 21 and the pressure roller 23 is 6 kg. The nip between the pressure roller 23 and the fixing film 22 is 3 mm, and the fixing film 22 has a low resistance release layer in which a conductive material is dispersed in PTFE on the contact surface with the transfer material, and has a heat resistance of 50 μm in thickness. A polyimide film was used.
[0332]
Further, the surface roughness Ra (μm) of the toner carrier used here is 1.5, and the material of the toner layer thickness regulating blade is stainless steel.
[0333]
In this embodiment, the image forming apparatus shown in FIG. 1 is used, and normal temperature and normal humidity (25 ° C., 60% RH), high temperature and high humidity (30 ° C., 80% RH), and low temperature and low humidity (15 ° C., 10%). In the RH) environment, the toners 1 to 12 of the present invention and the comparative toners 1 to 6 are developed in an intermittent mode (that is, developed for 10 seconds every time one sheet is printed out) at a printout speed of 28 sheets / minute (A4 size). The printer was paused, and a printout test of 5000 sheets was performed in a mode in which toner deterioration was promoted by a preliminary operation at the time of restart. The obtained printout image was evaluated for the items described below.
[0334]
<Printout image evaluation>
[0335]
(1) Image density
Ordinary paper for ordinary copying machines (75 g / m ² ) Using the image density at the end of the 5000 printout test. The image density was measured by using a “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.) to measure the relative density with respect to a printout image of a white background portion having a document density of 0.00.
A: 1.40 or more
B: 1.35 or more and less than 1.40
C: 1.00 or more and less than 1.35
D: Less than 1.00
[0336]
(2) Image fog
Using “Reflectometer MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.), the fog density (%) is calculated from the difference between the whiteness of the white area of the printout image and the whiteness of the transfer paper at the end of the printout test. Then, the image fog was evaluated. A green filter was used as the filter. Smaller numbers mean less fog.
A: Less than 1.5%
B: 1.5% or more and less than 2.5%
C: 2.5% or more and less than 4.0%
D: 4.0% or more
[0337]
(3) Halftone image uniformity
The image quality of the printout image at the end of the printout test was evaluated according to the following criteria.
A: Very good.
B: Good image although slightly distorted.
C: A level where there is no problem in practical use although it is cluttered.
D: Severe biting occurred.
[0338]
(4) Fixability
Fixability is 50 g / cm ² The fixed image was rubbed and reciprocated 5 times with a soft thin paper, and the reduction rate (%) of the image density before and after rubbing was evaluated.
A: Less than 5%
B: 5% or more and less than 10%
C: 10% or more and less than 20%
D: 20% or more
[0339]
(5) Offset resistance
The offset resistance was evaluated based on the degree of contamination on an image after printing out a sample image having an image area ratio of about 5%.
A: Dirt is not generated.
B: Dirt is slightly seen.
C: Some dirt is seen.
D: Significant contamination occurs.
[0340]
These evaluation results are shown in Table 9.
[0341]
[Table 9]

[0342]
<Example 2>
The toners 3 to 12 of the present invention and the comparative toners 3 to 7 obtained in the above toner production examples were evaluated as follows.
[0343]
First, as an image forming apparatus, an apparatus having the same structure as that of the image forming apparatus shown in FIG. Specifically, it is as follows.
[0344]
A 600 dpi laser beam printer (Canon: LBP-860) was prepared, and the process speed was modified to 60 mm / s.
[0345]
The cleaning rubber blade in the process cartridge was removed, and the charging method of the apparatus was direct charging with the rubber roller in contact with the electrostatic latent image carrier (photoconductor), and the applied voltage was DC component (-1200 V). Next, the development part in the process cartridge was modified. Medium resistance rubber roller made of silicone rubber with carbon black dispersed instead of stainless steel sleeve (diameter 16 mm, hardness ASKER C 45 degrees, resistance 10 ^Five (Ω · cm) was used as a toner carrier, and was in contact with the photoreceptor. The developing contact width at this time was set to about 3 mm. The rotational peripheral speed of the toner carrier is the same in the contact portion with the photoconductor, and is driven to be 150% with respect to the peripheral speed of the photoconductor.
[0346]
The photoconductor used here is an Al cylinder having a diameter of 30 mm and 254 mm as a base, and layers having the following constitutions are sequentially laminated by dip coating to prepare a photoconductor.
1) Conductive coating layer: Mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenolic resin (film thickness 1.5 μm).
2) Undercoat layer: mainly composed of modified nylon and copolymer nylon (film thickness 0.6 μm).
3) Charge generation layer: Mainly composed of a titanyl phthalocyanine pigment having absorption in a long wavelength region dispersed in a butyral resin (film thickness 0.6 μm).
4) Charge transport layer: Mainly composed of a hole transportable triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 by Ostwald viscosity method) at a mass ratio of 8:10 (film thickness 20 μm).
[0347]
As a means for applying the toner to the toner carrier, an application roller made of urethane foam rubber was provided in the developing device and brought into contact with the toner carrier. A voltage of about −550 V is applied to the application roller. Further, a stainless steel blade coated with a resin for controlling the coat layer of the toner on the toner carrier was attached so that the contact pressure with the toner carrier was a linear pressure of about 20 g / cm. The outline is shown in FIG. In addition, the applied voltage at the time of development was only a DC component (−450 V).
[0348]
The image forming apparatus was modified and the process conditions were set as follows so as to adapt to the modification of these process cartridges.
[0349]
The modified device uses a roller charger (applying only direct current) to uniformly charge the electrostatic latent image carrier. Subsequent to charging, an image portion is exposed with a laser beam to form an electrostatic latent image, and a visible image is formed with toner, and then a toner image is transferred to a transfer material by a roller to which a voltage is applied.
[0350]
The photosensitive member charging potential was -600V for the dark portion potential and -150V for the bright portion potential. As a transfer material, 75 g / m ² Paper was used.
[0351]
Using the image forming apparatus, a durability test was performed under the conditions of a temperature of 15 ° C./humidity of 10% using the toners 3 to 12 and the comparative toners 3 to 7 of the present invention.
[0352]
For durability evaluation, character printing was performed at a printing area ratio of 3%, and evaluation was performed as follows.
[0353]
(1) Contamination of charging roller of toner: Judgment was made based on the number of uneven charging due to contamination of the charging member on the halftone image.
A: Not occurring up to 3000 sheets
B: Generated between 2700 and less than 3000
C: Generated between 2000 and less than 2700
D: Generated with less than 2000 sheets
[0354]
(2) Toner photoconductor fusing and sleeve fusing: When white spots occurred on a solid black image, the surface of the photoconductor and the sleeve were observed to confirm the presence or absence of fusing. If no fusion was observed, the durability evaluation was continued.
A: Not occurring up to 3000 sheets
B: Generated between 2700 and less than 3000
C: Generated between 2000 and less than 2700
D: Generated with less than 2000 sheets
When charging roller contamination, photoconductor fusing, and sleeve fusing did not occur, image printing was continued up to 3000 sheets. The greater the number of sheets generated, the better the durability of the toner.
[0355]
(3) Transferability at the initial stage of durability: The solid black is the tape remaining from the transfer residual toner on the photoconductor during image development and stripped with Mylar tape. Evaluation was made by subtracting the number. Therefore, the smaller the value, the better the transferability.
A: Less than 0.05
B: 0.05 to less than 0.10
C: 0.10 to less than 0.20
D: 0.20 or more
[0356]
(4) Resolving power at the end of durability (at the time of 100 sheets) prints out an image of an isolated dot pattern with a small diameter (X = 50 μm) as shown in FIG. Reproducibility was evaluated.
A: Less than 2 defects / 100
B: 3-5 defects / 100 defects
C: 6-10 defects / 100 defects
D: 11 or more defects / 100
[0357]
(5) Offset property: Dirt generated on the back side of the image sample with 100 durability sheets was observed from the beginning, and the number of generated sheets was counted.
A: Not generated
B: Number of generated sheets 1-2 / 100
C: Generated number 3-5 / 100
D: Number of generated sheets 6 or more / 100 sheets
[0358]
(6) Measurement of fogging: Measured using a REFLECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. The filter used was a green filter, and the fog density (%) was calculated from the difference between the whiteness of the white portion of the measured printout image and the whiteness of the transfer paper, and the image fog was evaluated. The smaller the value, the less fog.
A: Less than 1.5%
B: 1.5% or more and less than 2.5%
C: 2.5% or more and less than 4.0%
D: 4.0% or more
These evaluation results are shown in Table 10.
[0359]
[Table 10]

[0360]
<Example 3>
The toner 5 of the present invention and the comparative toner 6 obtained in the above toner production examples were evaluated as follows.
[0361]
First, as the image forming apparatus, an apparatus having the same structure as that of the image forming apparatus shown in FIG.
[0362]
Specifically, it is as follows.
[0363]
The moving speed of the toner carrier surface is set to 150% of the moving speed of the electrostatic latent image carrier surface, and is 20 sheets / minute (A4 size) in a normal temperature and normal humidity (23 ° C., 65% RH) environment. ) A printout test of 6000 sheets with a print area ratio of 5% in a continuous mode in a single color with toners 5 and 6 'at a printout speed of 5) (that is, a mode that promotes toner consumption without pausing the developing device) It was. The obtained printout image was evaluated including the above-mentioned items and the contamination state on the intermediate transfer belt.
[0364]
(7) Toner intermediate transfer belt fusion, photoreceptor fusion, and sleeve fusion: At the stage where slight white spots have occurred on a solid black image, the intermediate transfer belt, photoreceptor surface and sleeve surface are observed and fused. The presence or absence was confirmed. If no fusion was observed, the durability evaluation was continued.
A: Not generated up to 6000 sheets
B: Generated between 5500 and less than 6000
C: Generated between 5000 and less than 5500
D: Generated with less than 5000 sheets
The results are shown in Table 11.
[0365]
[Table 11]

[0366]
【The invention's effect】
As described above, the dry toner of the present invention has excellent electrophotographic characteristics, gives a high-definition image, has excellent charging stability, and can be applied to an intermediate transfer member such as a toner carrier, an electrostatic latent image carrier, and a fixing device. There is also little pollution. Furthermore, the dry toner production method of the present invention can efficiently produce a toner having the above-described excellent electrophotographic characteristics and little contamination to the image forming apparatus.
[0367]
In addition, by using toner with improved strength in the vicinity of the particle surface, in a contact development type image forming process using a cleaner-less structure or an intermediate transfer body, resolution and transferability are maintained while maintaining fixability. It is possible to suppress the generation of ghosts by improving the toner recoverability, and to greatly improve the durability.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus to which an image forming method of the present invention can be applied.
FIG. 2 is a schematic configuration diagram of an image forming apparatus using an intermediate transfer belt for carrying out the image forming method of the present invention.
FIG. 3 is an exploded tilt view of a main part of the fixing device.
FIG. 4 is a cross-sectional view of an essential part showing a film state when the fixing device applicable to the image forming method of the present invention is not driven.
FIG. 5 is a schematic configuration diagram of an image forming apparatus that forms an image by a one-component development method.
FIG. 6 is a schematic configuration diagram of a developing device applicable to the image forming method of the present invention.
FIG. 7 is a diagram of a small-diameter isolated dot pattern for checking toner development characteristics.
FIG. 8 represents a graph for measuring the glass transition temperature.

Claims (39)

A dry toner having toner particles containing at least a binder resin, a colorant and a wax component and an external additive,
(1) The binder resin contains a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene,
(2) The main glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the toner is 40 to 70 ° C.,
(3) A (m ² / g) specific surface area by the BET method when left in an environment where the toner has an ambient temperature of 23 ° C. and a relative humidity of 65% for 72 hours, the toner ambient temperature of 50 ° C. and a relative humidity of 3% When the specific surface area according to the BET method when left in the environment for 72 hours is B (m ² / g), A and B satisfy the following formula:
0.8 ≦ A ≦ 4.0
0.80 ≦ (B / A) ≦ 1.05
(4) In the toner-based circle-equivalent diameter-circularity scattergram measured by the toner flow-type particle image measuring device, the circle equivalent number average diameter D1 of the toner is 2 to 10 μm. The average circularity is 0.950 to 0.995, the circularity standard deviation is less than 0.040,
(5) The tetrahydrofuran (THF) soluble content of the toner has a main peak molecular weight in the range of 2 × 10 ³ to 1 × 10 ⁵ in the molecular weight distribution measured by gel permeation chromatography (GPC). Insoluble matter is 5 to 60% by mass,
A dry toner. 2. The dry toner according to claim 1, wherein the total content of butadiene, isoprene and chloroprene contained in the binder resin is 0.1 to 20% by mass with respect to the toner. 2. The dry toner according to claim 1, wherein the total content of butadiene, isoprene and chloroprene contained in the binder resin is 0.1 to 10% by mass with respect to the toner. 4. The dry toner according to claim 1, wherein the binder resin contains a copolymer of styrene and / or a styrene derivative and butadiene. The dry toner according to any one of claims 1 to 4, wherein the charge control agent is a charge control agent represented by the following general formula (I).
[Outside 1]

[Wherein, X ₁ and X ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, and X ₁ and X ₂ may be the same or different, m and m ′ Represents an integer of 1 to 3, and R ₁ and R ₃ are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, a sulfonamide group, a mesyl group, a sulfonyl group, a hydroxyl group, carbon Represents an alkoxy group of formula 1 to 18, an acetylamino group, a benzoylamino group, a halogen atom or —COOR ₅ , R ₁ and R ₃ may be the same or different, and n and n ′ are 1 to 3 R ₂ and R ₄ represent a hydrogen atom or a nitro group, R ₅ represents an alkyl group or an aryl group, and A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, or an ammonium ion. ] The dry toner according to claim 1, wherein the toner has an average circularity of 0.970 to 0.995. 6. The dry toner according to claim 1, wherein the toner has an average circularity of 0.970 to 0.995 and a circularity standard deviation of less than 0.035. 8. The toner according to claim 1, wherein, in a toner equivalent number-based circle-circularity scattergram, the toner contains 15% by number or less of toner particles having a circularity of less than 0.950. 9. Dry toner. 9. The dry toner according to claim 1, wherein the binder resin contains 50 to 99.9% by mass of a styrene-acrylic resin. The dry toner according to claim 1, wherein the binder resin contains 80 to 99.9% by mass of a styrene-acrylic resin. The dry toner according to claim 1, wherein the binder resin contains 85 to 98% by mass of a styrene-acrylic resin. The dry toner according to claim 1, wherein the external additive is silica fine powder. The dry toner according to claim 12, wherein the fine silica powder has a BET specific surface area of 30 m ² / g or more. The dry toner according to claim 12, wherein the silica fine powder has a BET specific surface area of 50 to 400 m ² / g or more. The specific surface area according to the BET method when left in an environment with a toner ambient temperature of 23 ° C. and a relative humidity of 65% for 72 hours is A (m ² / g). The dry method according to any one of claims 1 to 14, wherein A and B satisfy the following formula when the specific surface area by the BET method when left for a time is B (m ² / g): toner.
0.8 ≦ A ≦ 4.0
0.90 ≦ (B / A) ≦ 1.05 The main peak molecular weight is in the range of 5 × 10 ^{3 to} 5 × 10 ⁴ in the molecular weight distribution measured by gel permeation chromatography (GPC) for the tetrahydrofuran (THF) soluble content of the toner. Item 16. The dry toner according to any one of Items 1 to 15. The dry toner according to claim 1, wherein the toner has a THF insoluble content of 5 to 55% by mass. Contains a diene monomer component-containing resin containing a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene, a polymerizable vinyl monomer, a colorant, a wax and a polymerization initiator. A method for producing toner particles by dispersing a polymerizable monomer composition in an aqueous medium, granulating it, and polymerizing in an aqueous medium.
When the polymerization initiator is a radical polymerization initiator (A) and the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass, the radical polymerization initiator (B) is newly added. A method for producing dry toner. The method for producing a dry toner according to claim 18, wherein the radical polymerization initiator (B) is water-soluble. The method for producing a dry toner according to claim 19, wherein the radical polymerization initiator (B) is a polymerization initiator selected from the group consisting of sodium persulfate, potassium persulfate, and ammonium persulfate. 19. The method for producing a dry toner according to claim 18, wherein the radical polymerization initiator (B) is oil-soluble and is added after being emulsified or dispersed in water. The radical polymerization initiator (B) is a polymerization initiator selected from an azo polymerization initiator, a diazo polymerization initiator, and a peroxide polymerization initiator. A method for producing dry toner. Contains a diene monomer component-containing resin containing a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene, a polymerizable vinyl monomer, a colorant, a wax and a polymerization initiator. A method for producing toner particles by dispersing a polymerizable monomer composition in an aqueous medium, granulating it, and polymerizing in an aqueous medium.
When the polymerization initiator is a radical polymerization initiator (A) and the conversion rate of the polymerization reaction is in the range of 10 to 95% by mass, the radical polymerization initiator (B) is newly added,
A dry toner manufacturing method, wherein the toner obtained is the toner according to claim 1. A charging step of applying a voltage to the charging member to charge the electrostatic latent image carrier; an electrostatic latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier; A developing process for forming a toner image on the electrostatic latent image carrier by attaching the toner carried on the toner carrier to the electrostatic latent image formed on the image carrier, and the electrostatic latent image carrier An image having a transfer step of electrostatically transferring a toner image formed thereon to a transfer material with or without an intermediate transfer member, and a fixing step of fixing the toner image electrostatically transferred to the transfer material A forming method comprising:
The toner is a dry toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an external additive,
(1) The binder resin contains a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene,
(2) The main glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the toner is 40 to 70 ° C.,
(3) A (m ² / g) specific surface area by the BET method when left in an environment where the toner has an ambient temperature of 23 ° C. and a relative humidity of 65% for 72 hours, the toner ambient temperature of 50 ° C. and a relative humidity of 3% When the specific surface area according to the BET method when left in the environment for 72 hours is B (m ² / g), A and B satisfy the following formula:
0.8 ≦ A ≦ 4.0
0.80 ≦ (B / A) ≦ 1.05
(4) In the toner-based circle-equivalent diameter-circularity scattergram measured by the toner flow-type particle image measuring device, the circle equivalent number average diameter D1 of the toner is 2 to 10 μm. The average circularity is 0.950 to 0.995, the circularity standard deviation is less than 0.040,
(5) The tetrahydrofuran (THF) soluble content of the toner has a main peak molecular weight in the range of 2 × 10 ³ to 1 × 10 ⁵ in the molecular weight distribution measured by gel permeation chromatography (GPC). Insoluble matter is 5 to 60% by mass,
An image forming method. 25. In the development step, the moving speed of the surface of the toner carrying member in the developing area is 1.05 to 3.0 times the moving speed of the surface of the electrostatic latent image carrying body. The image forming method described. 26. The image forming method according to claim 24, wherein the thickness of the toner layer on the toner carrier is regulated by a regulating member, and the regulating member is a ferromagnetic metal blade. 27. The image forming method according to claim 26, wherein the ferromagnetic metal blades are arranged at regular intervals so as to face the toner carrier. 26. The image forming method according to claim 24, wherein a toner layer thickness on the toner carrier is regulated by a regulating member, and the regulating member is a blade made of an elastic body. 29. The image forming method according to claim 28, wherein the blade made of the elastic body is brought into contact with and opposed to the toner carrier. The developing step is characterized in that the electrostatic latent image carrier and the toner carrier are arranged at a certain interval in the development step, and development is performed by forming an alternating electric field between them. 30. The image forming method according to any one of 24 to 29. 25. The development is performed while the electrostatic latent image formed on the electrostatic latent image carrier and the toner coated with a thin layer on the toner carrier are contacted in the developing step. 30. The image forming method according to any one of 29. 32. The image forming method according to claim 24, wherein in the charging step, the electrostatic latent image carrier is charged by bringing a charging member into contact with the electrostatic latent image carrier. 33. The image forming method according to claim 24, wherein, in the transfer step, the electrostatic latent image carrier and a transfer device are in contact with each other via the transfer material. 34. The image forming method according to claim 24, wherein the fixing step is a heat fixing step in which a toner image on the transfer material is heat-fixed. 35. The image forming method according to claim 34, wherein the heat-fixing step is a step of heat-pressing and fixing a toner image onto a transfer material using a heating member and a pressure member that is in pressure contact with the heating member. . 35. The image forming method according to claim 34, wherein a film is interposed between the transfer material and the heating body in the heat fixing step. 37. The developing and cleaning step of collecting a transfer residual toner remaining on the electrostatic latent image carrier after the transfer step by the toner carrier in the development step. Image forming method. After the transfer step, a toner reuse mechanism for cleaning and collecting the transfer residual toner remaining on the electrostatic latent image carrier, supplying the collected toner to the developing unit, and again for developing the electrostatic latent image is provided. 37. The image forming method according to claim 24, comprising: an image forming method according to claim 24; A charging step of applying a voltage to the charging member to charge the electrostatic latent image carrier; an electrostatic latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier; A developing process for forming a toner image on the electrostatic latent image carrier by attaching the toner carried on the toner carrier to the electrostatic latent image formed on the image carrier, and the electrostatic latent image carrier An image having a transfer step of electrostatically transferring a toner image formed thereon to a transfer material with or without an intermediate transfer member, and a fixing step of fixing the toner image electrostatically transferred to the transfer material A forming method comprising:
The toner is a dry toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an external additive,
(1) The binder resin contains a component derived from at least one monomer selected from the group consisting of butadiene, isoprene and chloroprene,
(2) The main glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the toner is 40 to 70 ° C.,
(3) A (m ² / g) specific surface area by the BET method when left in an environment where the toner has an ambient temperature of 23 ° C. and a relative humidity of 65% for 72 hours, the toner ambient temperature of 50 ° C. and a relative humidity of 3% When the specific surface area according to the BET method when left in the environment for 72 hours is B (m ² / g), A and B satisfy the following formula:
0.8 ≦ A ≦ 4.0
0.80 ≦ (B / A) ≦ 1.05
(4) In the toner-based circle-equivalent diameter-circularity scattergram measured by the toner flow-type particle image measuring device, the circle equivalent number average diameter D1 of the toner is 2 to 10 μm. The average circularity is 0.950 to 0.995, the circularity standard deviation is less than 0.040,
(5) The tetrahydrofuran (THF) soluble content of the toner has a main peak molecular weight in the range of 2 × 10 ³ to 1 × 10 ⁵ in the molecular weight distribution measured by gel permeation chromatography (GPC). Insoluble matter is 5 to 60% by mass,
An image forming method, wherein the toner is the toner according to claim 2.

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