JP3943785B2 - Dry toner, method for producing the toner, and image forming method using the toner - Google Patents

Description

【００３４】
また本発明は、該トナーの製造方法に関する。
【００３５】
さらに本発明は、該トナーを用いた画像形成方法に関する。
【００３６】
本発明者らは、鋭意検討の結果、上記一般式（１）の化合物と脂肪酸をトナーに含有させることにより、帯電の立ち上がりが良好で、プリントアウト速度を変化させた場合においても安定した帯電性を有する乾式トナーが得られることを見出し、本発明を完成するに至った。
【００３７】
【発明の実施の形態】
以下本発明について詳細に説明する。
【００３８】
本発明による乾式トナーは、少なくとも結着樹脂、着色剤、ワックス成分から構成されており、該トナーが下記一般式（１）で表される化合物および下記一般式（２）で表される炭素数６乃至４０の脂肪酸を含有していることが必須である。
【００３９】
【化７】

【００４０】
【化８】
一般式（２）

［ここで、Ｒ₇は炭素数５乃至３９の飽和又は不飽和炭化水素を表す。］
【００４１】
本発明で用いられる一般式（１）で表される化合物の代表的な具体例としては、次のような化合物が挙げられる。
【００４２】
【化９】

【００４３】
【化１０】

【００４４】
【化１１】

【００４５】
【化１２】

【００４６】
【化１３】

【００４７】
【化１４】

【００４８】
本発明で用いられる一般式（１）で表される化合物の含有量は、トナー粒子を基準として０．１〜１０質量％、より好ましくは０．２〜２質量％であり、この範囲をはずれると本発明の優れた帯電の立ち上がり性が発現しにくい。
【００４９】
本発明に用いられる炭素数６乃至４０の脂肪酸としては、カプリル酸、ノナン酸、カプリン酸、ウンデカン酸、ラウリン酸、トリデカン酸、ミリスチン酸、パルミチン酸、ステアリン酸、オレイン酸、リノール酸、２−メチルドデカン酸、２−メチルテトラデカン酸、２−メチルヘキサデカン酸、２−メチルオクタデカン酸、２−エチルドデカン酸、２−ブチルドデカン酸、２−エチルオクタデカン酸、ベヘニン酸など様々なものが例示されるが、これらの中で特に良好な帯電性が得られるのは炭素数１０乃至３０の脂肪酸である。また、これらの脂肪酸は例えばハロゲン原子等で置換されたものであってもよい。
【００５０】
本発明で用いられる脂肪酸の量は、トナーに対して３０乃至３０００ｐｐｍであることが好ましく、これよりも少ないと帯電性の向上効果が発現されない場合があり、これよりも多いと保存安定性に問題を生じたりする。また、特に好ましい脂肪酸の量は１００乃至１０００ｐｐｍであり、この範囲にすることでより安定した帯電性が発現する。
【００５１】
また、本発明のトナー中の一般式（１）の化合物および脂肪酸の定性・定量分析は、従来知られているあらゆる分析手段を使って実施することができる。例えば、トナーを核磁気共鳴スペクトル（¹Ｈ−ＮＭＲ、¹³Ｃ−ＮＭＲ）、赤外吸収スペクトル（ＩＲ）、ラマンスペクトル、紫外吸収スペクトル（ＵＶ）、質量スペクトル（ＭＳ）等のスペクトル分析、元素分析、蛍光Ｘ線、ガスクロマトグラフィー（ＧＣ）、液体クロマトグラフィー（ＨＰＬＣ）、その他の化学分析など様々な方法により分析すればよい。また、トナー自体では分析が困難な場合には、テトラヒドロフラン、トルエン等の結着樹脂を溶解する溶剤でトナーをソックスレー抽出し、残分と濾液を別々に分析すればよい。また、これらの分析手段は単独で、また必要に応じて組み合わせて用いることが可能である。
【００５２】
前記脂肪酸は、本発明のトナー粒子の表面に少なくとも一部が存在していることがさらに好ましく、表面に存在することにより迅速な帯電性が得られやすい。
【００５３】
本発明のトナー粒子表面の分析は、あらゆる分析手段を用いて実施することができる。一例を挙げれば、光音響分光法（ＰＡＳ＝ＰｈｏｔｏａｃｏｕｓｔｉｃＳｐｅｃｔｏｒｏｓｃｏｐｙ）を用い、可動鏡のスキャンスピードを変えることで、得られたトナー粒子表面の組成を赤外線吸収スペクトル（ＩＲ／ＰＡＳ）により分析することができる。この様にして、トナー粒子表面に本発明で用いられる脂肪酸が存在するかどうかを確認できる。また、ＩＲ／ＰＡＳの他にもラマン分光法と上記ＰＡＳを組み合わせたトナー表面の組成分析、ＥＳＣＡ（Ｅｌｅｃｔｒｏｎ Ｓｐｅｃｔｒｏｓｃｏｐｙ ｆｏｒ Ｃｈｅｍｉｃａｌ Ａｎａｌｙｓｉｓ）によるトナー表面の元素分析、エネルギー分散型Ｘ線分光器や電子線エネルギー分析器を取り付けた電子顕微鏡によるトナー表面の元素分析など様々な分析手段がある。これらの分析手段は単独で、また必要に応じて組み合わせて用いられる。
【００５４】
本発明のトナーに用いられるワックス成分としては、例えばパラフィンワックス及びその誘導体、マイクロクリスタリンワックス及びその誘導体、フィッシャートロプシュワックス及びその誘導体、ポリオレフィンワックス及びその誘導体、カルナバワックス及びその誘導体などで、誘導体には酸化物や、ビニル系モノマーとのブロック共重合物、グラフト変性物を含む。その他、高級脂肪酸およびその金属塩、高級脂肪族アルコール、高級脂肪族エステル、脂肪族アミドワックス、ケトン、硬化ヒマシ油及びその誘導体、植物系ワックス、動物性ワックス、鉱物系ワックス、ペトロラクタムなど様々なものが挙げられる。
【００５５】
これらのワックス成分は、示差走差熱量計により測定されるＤＳＣ曲線において、昇温時に４０〜１５０℃の領域に最大吸熱ピークを有する。上記温度領域に最大吸熱ピークを有することにより、低温定着に大きく貢献しつつ、離型性をも効果的に発現する。該最大吸熱ピークが４０℃未満であるとワックス成分の自己凝集力が弱くなり、結果として耐高温オフセット性が悪化するとともに、グロスが高くなりすぎる。一方、該最大吸熱ピークが１５０℃を超えると定着温度が高くなるとともに、定着画像表面を適度に平滑化せしめることが困難となるため、特にカラートナーに用いた場合には混色性低下の点から好ましくない。さらに、水系媒体中で造粒／重合を行い重合方法により直接トナーを得る場合、該最大吸熱ピーク温度が高いと主に造粒中にワックス成分が析出する等の問題を生じ好ましくない。従って、吸熱ピークが５０〜１００℃の範囲にあるワックスを用いることが、低温定着性と高品位な画像が得られる点で特に好ましい。
【００５６】
ワックス成分の最大吸熱ピーク温度の測定は、「ＡＳＴＭ Ｄ ３４１８−８」に準じて行う。測定には、例えばパーキンエルマー社製ＤＳＣ−７を用いる。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℃／ｍｉｎで測定を行う。
【００５７】
本発明においては、これらのワックス成分の添加量は特に限定されないが、トナーに対して０．５〜３０質量％の範囲が好ましい。
【００５８】
本発明によるトナーの製造方法としては様々な方法が挙げられるが、例えば粉砕法により製造する場合には、前記一般式（１）で表される化合物、前記一般式（２）で表される脂肪酸、結着樹脂、ワックス成分、着色剤および／または磁性体、必要に応じて荷電制御剤またはその他の添加剤等をヘンシェルミキサー、ボールミルのごとき混合機により充分混合し、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および球形化処理を行う。次いで、分級工程を経て粒度分布をシャープにする。さらに、分級粉を微粒子シリカ等の流動化剤とヘ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。また、その他のトナーの製造方法として、分級粉に流動化剤とともに、あるいは別々に微粉化した一般式（１）で表される化合物および／または一般式（２）で表される脂肪酸を加えて充分混合し、トナー表面に一般式（１）で表される化合物や一般式（２）で表される脂肪酸を固着させる方法もあり、この場合、分級粉中に一般式（１）で表される化合物や一般式（２）で表される脂肪酸が含有されていてもよいし、含有されていなくてもよい。また、固着させた後にトナー粒子の平滑化および球形化処理を行ってもよい。
【００５９】
さらに、重合法により本発明のトナーを製造する場合には、単量体組成物にあらかじめ一般式（１）で表される化合物や一般式（２）で表される脂肪酸を含有させ、特公昭３６−１０２３１号公報、特開昭５９−５３８５６号公報、特開昭５９−６１８４２号公報に述べ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などが採用できる。また、重合法により一般式（１）で表される化合物および／または一般式（２）で表される脂肪酸を含有しない重合体粒子を製造し、その後、重合体粒子の表面に微粒子状の一般式（１）で表される化合物および／または一般式（２）で表される脂肪酸を付着させ、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や、一般式（１）で表される化合物および／または一般式（２）で表される脂肪酸を含有する単量体組成物をシード重合する方法も採用することができる。また、その他の方法として、特公昭５６−１３９４５号公報等に記載のディスク又は多流体ノズルを用い一般式（１）で表される化合物および一般式（２）で表される脂肪酸を含有する溶融混合物を空気中に霧化し球形トナーを得る方法などが例示される。
【００６０】
本発明において使用できる結着樹脂としては、一般に用いられているスチレン−アクリル系樹脂、ポリエステル系樹脂、エポキシ系樹脂等様々な樹脂が挙げられ、特にスチレン−アクリル系樹脂が好適に使用される。これらの樹脂はあらゆる公知の方法により製造すればよく、例えばスチレン−アクリル系樹脂は、それらを形成するための単量体を重合することにより得ることができる。具体的には、スチレン、ｏ（ｍ−，ｐ−）−メチルスチレン、ｍ（ｐ−）−エチルスチレンの如きスチレン系単量体、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸オクチル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸ベヘニル、（メタ）アクリル酸２−エチルヘキシル、（メタ）アクリル酸ジメチルアミノエチル、（メタ）アクリル酸ジエチルアミノエチルの如き（メタ）アクリル酸エステル系単量体、ブタジエン、イソプレン、シクロヘキセン、（メタ）アクリロニトリル、アクリルアミドの如きエン系単量体が好ましく用いられる。これらは単独、または一般的には出版物ポリマーハンドブック第２版ＩＩＩ−ｐ１３９〜１９２（Ｊｏｈｎ Ｗｉｌｅｙ＆Ｓｏｎｓ社製）に記載の理論ガラス転移温度（Ｔｇ）が、４０〜７５℃を示すように単量体を適宜混合して用いられる。理論ガラス転移温度が４０℃未満の場合にはトナーの保存安定性や耐久安定性の面から問題が生じやすく、一方７５℃を超える場合にはトナーの定着点の上昇をもたらす。特にフルカラー画像を形成するためのカラートナーの場合においては各色トナーの定着時の混色性が低下し色再現性に乏しく、さらにＯＨＰ画像の透明性が低下するため好ましくない。
【００６１】
また、前記結着樹脂と併用して他の結着樹脂を用いることもでき、その材料によってはトナー粒子の最表層を他の結着樹脂で覆い、保存安定性や耐久性を向上させることも可能である。但し、他の結着樹脂を併用する場合でも、好ましくはスチレン−アクリル系樹脂の含有量が全結着樹脂に対して５０〜１００質量％、より好ましくは８０〜１００質量％の範囲であり、５０質量％よりも含有量が少ないと低温定着性と現像性のバランスを取るのが困難になる。
【００６２】
結着樹脂の分子量は、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。具体的なＧＰＣの測定方法としては、結着樹脂またはトナーをテトラヒドロフラン（ＴＨＦ）に室温で２４時間かけて溶解した溶液を、ポア径が０．２μｍの耐溶剤性メンブランフィルターで濾過してサンプル溶液とし、以下の条件で測定する。尚、サンプル調製は、ＴＨＦに可溶な成分の濃度が０．４〜０．６質量％になるようにＴＨＦの量を調整する。
装置 ：高速ＧＰＣ ＨＬＣ８１２０ ＧＰＣ（東ソー社製）
カラム：Ｓｈｏｄｅｘ ＫＦ−８０１、８０２、８０３、８０４、８０５、８０６、８０７の７連（昭和電工社製）
溶離液：テトラヒドロフラン
流速 ：１．０ｍｌ／ｍｉｎ
オーブン温度：４０．０℃
試料注入量：０．１０ｍｌ
【００６３】
また、試料の分子量の算出にあたっては、標準ポリスチレン樹脂（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）により作成した分子量校正曲線を使用する。
【００６４】
重合法により本発明のトナーを製造する場合には、得られた重合体粒子の結着樹脂のＧＰＣにおける主たるピークの分子量は３０００〜１０００００であり、特に好ましくは５０００〜５００００である。
【００６５】
本発明のトナーの形状は特に制限されないが、転写性と現像性をバランス良く改善するためには、以下のような形状が好ましい。すなわち、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０．９２０〜０．９９５、好ましくは０．９５０〜０．９９５、更に好ましくは０．９７０〜０．９９５で、円形度標準偏差が０．０６０未満、好ましくは０．０５０未満、更に好ましくは０．０４０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。
【００６６】
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いていた。
【００６７】
これに対し、本発明によれば円相当個数平均径を２〜１０μｍと小粒径化しても微小粒径のトナーの存在率を低くすることが可能であり、例えば個数基準における全トナー粒子数に対する２μｍ以下の粒子数の割合は、通常４０個数％未満とすることができる。
【００６８】
円形度頻度分布の円形度標準偏差と微小粒径のトナーの存在率を上記の様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。その理由として本発明者らは、現像工程においてトナー担持体上にトナーの薄層を形成する際に、トナー層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ている。
【００６９】
また、円形度頻度分布の平均円形度を上記の様に制御することにより、従来では困難であった小粒径を呈するトナーの転写性が大幅に改善させ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。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。
【００７０】
平均円形度は、０．９７０以上が特に好ましく、これ未満である場合には、転写性の悪化や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様になる。
【００７１】
本発明におけるトナーの円相当径、円形度及びそれらの頻度分布とは、トナー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、本発明ではフロー式粒子像測定装置ＦＰＩＡ−１０００型（東亜医用電子社製）を用いて測定を行い、下式を用いて算出した。
【００７２】
【数１】

【００７３】
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。
【００７４】
本発明における円形度はトナー粒子の凹凸の度合いを示す指標であり、トナー粒子が完全な球形の場合に１．００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。
【００７５】
本発明において、トナーの個数基準の粒径頻度分布の平均値を意味する円相当個数平均粒子径Ｄ１と粒径標準偏差ＳＤｄは、粒度分布の分割点ｉでの粒径（中心値）をｄｉ、頻度をｆ_iとすると次式から算出される。
【００７６】
【数２】

【００７７】

【００７８】
【数３】

【００７９】
具体的な測定方法としては、容器中に予め不純固形物などを除去したイオン交換水１０ｍｌ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、更に測定試料を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５φ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、該分散液の温度が４０℃以上とならない様に適宜冷却する。
【００８０】
トナー粒子の形状測定には、前記フロー式粒子像測定装置を用い、測定時のトナー粒子濃度が３０００〜１万個／μｌとなる様に該分散液濃度を再調整し、トナー粒子を１０００個以上計測する。計測後、このデータを用いて、トナーの円相当径や円形度頻度分布等を求める。
【００８１】
本発明に用いられる着色剤は、以下に示すイエロー着色剤、マゼンタ着色剤およびシアン着色剤が挙げられ、黒色着色剤としてカーボンブラック、磁性体、または以下に示すイエロー着色剤／マゼンタ着色剤／シアン着色剤を混合して黒色に調色されたものが利用される。
【００８２】
イエロー着色剤としては、縮合アゾ化合物、イソインドリノン化合物、アンスラキノン化合物、アゾ金属錯体、メチン化合物、アリルアミド化合物に代表される化合物等が用いられる。具体的には、Ｃ．Ｉ．ピグメントイエロー１２、１３、１４、１５、１７、６２、７４、８３、９３、９４、９５、１０９、１１０、１１１、１２８、１２９、１４７、１６８、１８０等が好適に用いられる。
【００８３】
マゼンタ着色剤としては、縮合アゾ化合物、ジケトピロロピロール化合物、アンスラキノン、キナクリドン化合物、塩基染料レーキ化合物、ナフトール化合物、ベンズイミダゾロン化合物、チオインジゴ化合物、ペリレン化合物等が用いられる。具体的には、Ｃ．Ｉ．ピグメントレッド２、３、５、６、７、２３、４８：２、４８：３、４８：４、５７：１、８１：１、１４４、１４６、１６６、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４が特に好ましい。
【００８４】
シアン着色剤としては、銅フタロシアニン化合物及びその誘導体、アンスラキノン化合物、塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．ピグメントブルー１、７、１５、１５：１、１５：２、１５：３、１５：４、６０、６２、６６等が特に好適に利用できる。
【００８５】
これらの着色剤は、単独又は混合し更には固溶体の状態で用いることができる。着色剤は、色相，彩度，明度，耐候性，ＯＨＰ透明性，トナー粒子中への分散性の点から選択される。該着色剤の添加量は、樹脂成分１００質量部に対し１〜２０質量部使用するのが好ましい。
【００８６】
さらに本発明のトナーは黒色着色剤として磁性材料を使用し、磁性トナーとしても使用し得る。この際使用することのできる磁性材料としては、マグネタイト、ヘマタイト、フェライト等の酸化鉄、鉄、コバルト、ニッケルのような金属あるいはこれらの金属のアルミニウム、コバルト、銅、鉛、マグネシウム、スズ、亜鉛、アンチモン、ベリリウム、ビスマス、カドニウム、カルシウム、マンガン、セレン、チタン、タングステン、バナジウムのような金属の合金及びその混合物があげられる。
【００８７】
本発明に用いられる磁性体は、表面改質された磁性体であることがより好ましく、重合法トナーに用いる場合には、重合阻害のない物質である表面改質剤により、疎水化処理を施したものが好ましい。このような表面改質剤としては、例えばシランカップリング剤、チタンカップリング剤等を例示することができる。
【００８８】
これらの磁性体は平均粒径が２μｍ以下、好ましくは０．１〜０．５μｍ程度のものである。トナー粒子中に含有させる磁性体の量としては樹脂１００質量部に対し２０〜２００質量部、特に好ましくは４０〜１５０質量部である。また、７９６ｋＡ／ｍ（１０ｋエルステッド）印加での磁気特性が保磁力（Ｈｃ）１．６〜２４ｋＡ／ｍ、飽和磁化（σｓ）５０〜２００Ａｍ²／ｋｇ、残留磁化（σｒ）２〜２０Ａｍ²／ｋｇの磁性体が好ましい。
【００８９】
本発明において一般式（１）とともに併用できる荷電制御剤としては、公知のものが利用でき、特に帯電スピードが速く、且つ、一定の帯電量を安定して維持できる荷電制御剤が好ましい。更に、トナー粒子を直接重合法を用いる場合には、重合阻害性が無く水系分散媒体への可溶化物の無い荷電制御剤が特に好ましい。具体的化合物としては、ネガ系荷電制御剤としてサリチル酸、ナフトエ酸、ダイカルボン酸の如き芳香族カルボン酸の金属化合物；スルホン酸又はカルボン酸基を側鎖に持つ高分子型化合物；ホウ素化合物；尿素化合物；ケイ素化合物；カリークスアレーン等が挙げられる。ポジ系荷電制御剤として、四級アンモニウム塩；該四級アンモニウム塩を側鎖に有する高分子型化合物；グアニジン化合物；イミダゾール化合物等が挙げられる。該荷電制御剤は樹脂１００質量部に対し０．０５〜１０質量部使用することが好ましい。
【００９０】
本発明において、トナーの断層面観察の具体的方法としては、常温硬化性のエポキシ樹脂中にトナー粒子を充分分散させた後４０℃の雰囲気下で２日間硬化させ得られた硬化物を四三酸化ルテニウム、必要により四三酸化オスミウムを併用し染色を施した後、ダイヤモンド歯を備えたミクロトームを用い薄片状のサンプルを切り出して透過電子顕微鏡を用いトナーの断層面を観察する。本発明においては、用いるワックス成分と外殻を構成する結着樹脂との若干の結晶化度の違いを利用して材料間のコントラストをつけるため四三酸化ルテニウム染色法を用いることが好ましい。代表的な一例を図７ａ、７ｂに示す。
【００９１】
後記の実施例１および７で得られたトナー粒子（１）および（７）をＴＥＭにて断層面観察したところ、トナー粒子（１）の場合には、ワックス成分が結着樹脂中に実質的に球状および紡錘形の島状に分散されている様子が観察され、トナー粒子（７）の場合には、ワックス成分が結着樹脂中に微分散されている様子が観察された。
【００９２】
トナーの製造方法として重合方法を利用する場合、トナー粒子の粒度分布制御や粒径の制御は、難水溶性の無機塩や保護コロイド作用をする分散剤の種類や添加量を変える方法や機械的装置条件（例えばローターの周速、パス回数、撹拌羽根形状等の撹拌条件や容器形状）又は、水溶液中での固形分濃度等を制御することにより所定のトナー粒子を得ることができる。
【００９３】
直接重合法によりトナーを製造する際、用いられる重合開始剤として例えば、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又はジアゾ系重合開始剤；ベンゾイルペルオキシド、メチルエチルケトンペルオキシド、ジイソプロピルペルオキシカーボネート、クメンヒドロペルオキシド、２，４−ジクロロベンゾイルペルオキシド、ラウロイルペルオキシドの如き過酸化物系重合開始剤が用いられる。該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、単独又は混合して使用される。
【００９４】
重合度を制御するため公知の架橋剤，連鎖移動剤，重合禁止剤等を更に添加し用いても良い。
【００９５】
トナーの製法として分散安定剤を用いた懸濁重合法を利用する場合、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，アルミナ等が挙げられる。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，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，デンプン等が挙げられる。これらを水相に分散させて使用できる。これら分散安定剤は、重合性単量体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。
【００９６】
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、分散媒体中にて該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、高速撹拌下において、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と良い。
【００９７】
これら分散安定剤の微細な分散の為に、０．００１〜０．１質量部の界面活性剤を併用してもよい。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，ラウリル酸ナトリウム，ステアリン酸カリウム，オレイン酸カルシウム等が挙げられる。
【００９８】
本発明で使用するトナーの製造方法として直接重合法を用いる場合においては、以下の如き製造方法が可能である。
【００９９】
重合性単量体中に、ワックス成分，着色剤，荷電制御剤，重合開始剤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た単量体組成物を、分散安定剤を含有する水相中に通常の撹拌機またはホモミキサー，ホモジナイザー等により分散せしめる。好ましくは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撹拌速度，撹拌時間を調整し、造粒する。その後は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撹拌を行えば良い。重合温度は４０℃以上、一般的には５０〜９０℃の温度に設定して重合を行うのが良い。重合反応後半に昇温しても良く、更に、本発明における画像形成方法における耐久性向上の目的で、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・濾過により回収し、乾燥する。懸濁重合法においては、通常単量体組成物１００質量部に対して水３００〜３０００質量部を分散媒体として使用するのが好ましい。
【０１００】
次に本発明のトナーが適用される画像形成方法を添付図面を参照しながら以下に説明する。
【０１０１】
本発明のトナーは種々の現像方式に適用できる。一例として、図１に、静電潜像担持体上に形成された静電像を一成分現像により現像する装置の一例を示すが、必ずしもこれに限定されるものではない。
【０１０２】
図１において、２５は静電潜像担持体（感光ドラム）であり、潜像形成は電子写真プロセス手段または静電記録手段によりなされる。２４はトナー担持体（現像スリーブ）であり、アルミニウムあるいはステンレス等からなる非磁性スリーブからなる。
【０１０３】
現像スリーブ２４の略右半周面はトナー容器２１内のトナー溜まりに常時接触していて、その現像スリーブ面近傍のトナーが現像スリーブ面にスリーブ内の磁気発生手段の磁力で及び／または静電気力により付着保持される。
【０１０４】
本発明では、トナー担持体の表面粗度Ｒａ（μｍ）を１．５以下となるように設定する。好ましくは１．０以下である。さらに好ましくは０．５以下である。
【０１０５】
該表面粗度Ｒａを１．５以下にすることでトナー担持体の有するトナー粒子の搬送能力を抑制し、該トナー担持体上のトナー層を薄層化すると共に、該トナー担持体とトナーの接触回数が多くなるため、該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。
【０１０６】
該トナー担持体の表面粗度Ｒａが１．５を超えると、該トナー担持体上のトナー層の薄層化が困難となるばかりか、トナーの帯電性が改善されないので画質の向上は望めない。
【０１０７】
本発明において、トナー担持体の表面粗度Ｒａは、ＪＩＳ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に相当する。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ミクロメートル（μｍ）で表したものを言う。
【０１０８】
【数４】

【０１０９】
本発明に用いられるトナー担持体としては、例えばステンレス、アルミニウム等からなる円筒状、あるいはベルト状部材が好ましく用いられる。また必要に応じ表面を金属、樹脂等のコートをしてもよく、樹脂や金属類、カーボンブラック、帯電制御剤等の微粒子を分散した樹脂をコートしても良い。
【０１１０】
本発明では、トナー担持体の表面移動速度を静電潜像担持体の表面移動速度に対し１．０５〜３．０倍となるように設定することで、該トナー担持体上のトナー層は適度な撹拌効果を受けるため、静電潜像の忠実再現が一層良好なものとなる。
【０１１１】
該トナー担持体の表面移動速度が、静電潜像担持体の表面移動速度に対し１．０５倍未満であると、該トナー層の受ける撹拌効果が不十分となり、良好な画像形成は望めない。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る。逆に３．０倍を超える場合には、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、促進され、好ましくない。
【０１１２】
トナーＴはホッパー２１に貯蔵されており、供給部材２２によって現像スリーブ上へ供給される。供給部材として、多孔質弾性体、例えば軟質ポリウレタンフォーム等の発泡材よりなる供給ローラが好ましく用いられる。該供給ローラを現像スリーブに対して、順または逆方向に０でない相対速度を持って回転させ、現像スリーブ上へのトナー供給と共に、スリーブ上の現像後のトナー（未現像トナー）のはぎ取りも行う。この際、供給ローラの現像スリーブヘの当接幅は、トナーの供給及びはぎ取りのバランスを考慮すると、２．０〜１０．０ｍｍが好ましく、４．０〜６．０ｍｍがより好ましい。その一方で、トナーに対する過大なストレスを余儀なくされ、トナーの劣化による凝集の増大、あるいは現像スリーブ、供給ローラ等へのトナーの融着・固着が生じやすくなるが、本発明の現像法に用いられるトナーは、流動性、離型性に優れ、耐久安定性を有しているので、該供給部材を有する現像法においても好ましく用いられる。また、供給部材としては、ナイロン、レーヨン等の樹脂繊維よりなるブラシ部材を用いても良い。尚、これらの供給部材は磁気拘束力を利用できない非磁性一成分トナーを使用する一成分現像方法において極めて有効であるが、磁性一成分トナーを使用する一成分現像方法に使用しても良い。
【０１１３】
現像スリーブ上に供給されたトナーは規制部材によって薄層かつ均一に塗布される。トナー薄層化規制部材は、現像スリーブと一定の間隔において配置される金属ブレード、磁性ブレード等のドクターブレードである。あるいは、ドクターブレードの代わりに、金属、樹脂、セラミックスなどを用いた剛体ローラやスリーブを用いてもよく、それらの内部に磁気発生手段を用いても良い。
【０１１４】
また、トナー薄層化の規制部材としてトナーを圧接塗布するための弾性ブレードや弾性ローラの如き弾性体を用いても良い。例えば、図１において、弾性ブレード２３はその上辺部側である基部を現像剤容器２１側に固定保持され、下辺部側をブレードの弾性に抗して現像スリーブ２４の順方向あるいは逆方向にたわめ状態にしてブレード内面側（逆方向の場合には外面側）をスリーブ２４表面に適度の弾性押圧をもって当接させる。この様な装置によると、環境の変動に対しても安定で、緻密なトナー層が得られる。その理由は必ずしも明確ではないが、該弾性体によって現像スリーブ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帯電が行われるためと推測される。
【０１１５】
その一方で、帯電が過剰になりやすく、現像スリーブや弾性ブレード上にトナーが融着しやすいが、本発明に用いられるトナーは離型性に優れ、摩擦帯電性が安定しているので好ましく用いられる。
【０１１６】
該弾性体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が使用できる。また、それらの複合体であっても良い。
【０１１７】
また、弾性体とトナー担持体に耐久性が要求される場合には、金属弾性体に樹脂やゴムをスリーブ当接部に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。
【０１１８】
更に、弾性体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、界面活性剤など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等の成型体の場合には、シリカ、アルミナ、チタニア、酸化錫、酸化ジルコニア、酸化亜鉛等の金属酸化物微粉末、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等を含有させることも好ましい。
【０１１９】
またさらに、規制部材である現像ブレード、供給部材である供給ローラ、ブラシ部材に直流電場及び／または交流電場を印加することによっても、トナーヘのほぐし作用のため現像スリーブ上の規制部材においては、均一薄層塗布性、均一帯電性がより向上し、供給部材においては、トナーの供給／はぎ取りがよりスムーズになされ、充分な画像濃度の達成及び良質の画像を得ることができる。
【０１２０】
該弾性体とトナー担持体との当接圧力は、トナー担持体の母線方向の線圧として、０．１ｋｇ／ｍ以上、好ましくは０．３〜２５ｋｇ／ｍ、さらに好ましくは０．５〜１２ｋｇ／ｍが有効である。これによりトナーの疑集を効果的にほぐすことが可能となり、トナーの帯電量を瞬時に立ち上げることが可能である。当接圧力が０．１ｋｇ／ｍより小さい場合、トナーの均一塗布が困難となり、トナーの帯電量分布がブロードになりカブリや飛散の原因となる。また、当接圧力が２５ｋｇ／ｍを超えると、トナーに大きな圧力がかかり、トナーが劣化したり、トナーの凝集物が発生するなど好ましくない。またトナー担持体を駆動させるために大きなトルクを要するため好ましくない。
【０１２１】
静電潜像担持体とトナー担持体との間隙αは、５０〜５００μｍに設定され、ドクターブレードとトナー担持体との間隙は、５０〜４００μｍに設定されることが好ましい。
【０１２２】
トナー担持体上のトナー層の層厚は、静電潜像担持体とトナー担持体との間隙αよりも薄いことが最も好ましいが、場合によりトナー層を構成する多数のトナーの穂のうち、一部は静電潜像担持体に接する程度にトナー層の層厚を規制しても良い。
【０１２３】
一方、トナー担持体には、バイアス電源２６により静電潜像担持体との間に交番電界を印加することにより、トナー担持体から静電潜像担持体へのトナーの移動を容易にし、さらに良質の画像を得ることができる。交番電界のＶｐｐは１００Ｖ以上、好ましくは２００〜３０００Ｖ、さらに好ましくは３００〜２０００Ｖで用いるのがよい。また、ｆは５００〜５０００Ｈｚ、好ましくは１０００〜３０００Ｈｚ、さらに好ましくは１５００〜３０００Ｈｚで用いられる。この場合の波形は、矩形波、サイン波、のこぎり波、三角波等の波形が適用できる。また、正、逆の電圧、時間の異なる非対称交流バイアスも利用できる。また直流バイアスを重畳するのも好ましい。
【０１２４】
静電潜像担持体２５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である。静電潜像担持体１は、図示しない駆動装置によって矢印方向に回転される。
【０１２５】
静電潜像担持体２５としては、アモルファスシリコン感光層、または有機系感光層を有する感光体が好ましく用いられる。
【０１２６】
有機系感光層としては、感光層が電荷発生物質および電荷輸送機能を有する物質を同一層に含有する単一層型でもよく、または、電荷輸送層と電荷発生層を成分とする機能分離型感光層であっても良い。導電性基体上に電荷発生層、次いで電荷輸送層の順で積層されている構造の積層型感光層は好ましい例の一つである。
【０１２７】
有機系感光層の結着樹脂はポリカーボネート樹脂、ポリエステル樹脂、アクリル系樹脂が特に、転写性、クリーニング性がよく、クリーニング不良、感光体へのトナーの融着、外添剤のフィルミングが起こりにくい。
【０１２８】
帯電工程では、コロナ帯電器を用いる静電潜像担持体２５とは非接触である方式と、ローラ等を用いる接触型の方式があり、何れのものも用いられる。効率的な均一帯電、シンプル化、低オゾン発生化のために接触方式のものが好ましく用いられる。
【０１２９】
次に、中間転写ベルトを用いた画像形成装置の一例の概略図を図２に示す。
【０１３０】
図２は電子写真プロセスを利用したカラー画像形成装置（複写機あるいはレーザービームプリンター）である。
【０１３１】
１は第１の画像担持体としてのドラム状の電子写真感光体（以下感光ドラムと記す）であり、矢印の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。
【０１３２】
感光ドラム１は回転過程で、一次帯電器２により所定の極性・電位に一様に帯電処理され、次いで不図示の像露光手段３による露光３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。
【０１３３】
次いで、その静電潜像が第１の現像器（イエロー色現像器４１）により第１色であるイエロー成分像に現像される。この時第２〜第４の現像器、即ちマゼンタ現像器４２、シアン色現像器４３、およびブラック色現像器４４は作動しておらず、感光ドラム１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。
【０１３４】
中間転写ベルト４０は、矢印の方向に感光ドラム１と同じ周速度で回転駆動される。
【０１３５】
感光ドラム１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１と中間転写ベルト４０とのニップ部を通過する過程で、一次転写ローラ６２を介してバイアス電源４９から中間転写ベルト４０に印加される一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４０の外周面に順次転写（一次転写）されていく。
【０１３６】
中間転写ベルト４０に対応する第１色のイエロートナー画像の転写を終えた感光ドラム１の表面は、第１のクリーニング装置５３により清掃される。
【０１３７】
以下、同様に第２色のマゼンタトナー画像、第３色のシアントナー画像、第４色のブラックトナー画像が順次中間転写ベルト４０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画像が形成される。
【０１３８】
６３は二次転写ローラで、二次転写対向ローラ６４に対応し平行に軸受させて中間転写ベルト４０の下面部に離間可能な状態に配設してある。
【０１３９】
トナー画像を感光ドラム１から中間転写ベルト４０へ転写するための一次転写バイアスは、トナーとは逆極性でバイアス電源４９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。
【０１４０】
感光ドラム１から中間転写ベルト４０への第１〜第３色のトナー画像の一次転写工程において、二次転写ローラ６３及び転写残トナー帯電部材５２は中間転写ベルト４０から離間することも可能である。
【０１４１】
中間転写ベルト４０上に転写されたフルカラー画像は、二次転写ローラ６３が中間転写ベルト４０に当接され、給紙ローラ５１から中間転写ベルト４０と二次転写ローラ６３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、二次転写バイアスがバイアス電源４８から二次転写ローラ６３に印加されることにより転写材Ｐに二次転写される。トナー画像が転写された転写材Ｐは、定着器５５へ導入され加熱定着される。
【０１４２】
転写材Ｐへの画像転写終了後、中間転写ベルト４０には転写残トナークリーニング装置５２が当接され、中間転写ベルト４０の表面が清掃される。
【０１４３】
次に、クリーナレスプロセスを用いた場合の、単色での画像形成方法について図３を用いて説明する。
【０１４４】
図３において、１００は現像装置、１０９は感光体、１０５は紙などの被転写体、１０６は転写部材、１０７は定着用加圧ローラ、１０８は定着用加熱ローラ、１１０は感光体１０９に接触して直接帯電を行う一次帯電部材を示す。
【０１４５】
一次帯電部材１１０には、感光体１０９表面を一様に帯電するようにバイアス電源１１５が接続されている。
【０１４６】
現像装置１００はトナー１０４を収容しており、感光体１０９と接触して矢印方向に回転するトナー担持体１０２を具備する。さらに、トナー量規制及び帯電付与のための現像ブレード１０１，トナー１０４をトナー担持体１０２に付着させかつトナー担持体１０２との摩擦でトナーヘの帯電付与を行うため矢印方向に回転する塗布ローラ１０３も備えている。トナー担持体１０２には現像バイアス電源１１７が接続されている。塗布ローラ１０３にもバイアス電源１１８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。
【０１４７】
転写部材１０６には感光体１０９と反対極性の転写バイアス電源１１６が接続されている。ここで、感光体１０９とトナー担持体１０２の接触部分における回転方向の長さ、いわゆる現像ニップ幅は０．２ｍｍ以上８．０ｍｍ以下が好ましい。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。８．０ｍｍを超えてしまうと、トナーの供給量が過剰となり、カブリ抑制が悪化しやすく、また、感光体の摩耗にも悪影響を及ぼす。
【０１４８】
トナー担持体としては、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。使用される弾性層の材料の硬度としては、２０〜６５度（ＪＩＳＡ）のものが好適に使用される。また、トナー担持体の抵抗としては、体積抵抗値で１０²〜１０⁹Ωｃｍ程度の範囲が好ましい。１０²Ωｃｍよりも低い場合、例えば感光体１０９の表面にピンホール等がある場合、過電流が流れる恐れがある。反対に１０⁹Ωｃｍ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。
【０１４９】
トナー担持体上のトナーコート量は、０．１ｍｇ／ｃｍ²以上１．５ｍｇ／ｃｍ²以下が好ましい。０．１ｍｇ／ｃｍ²よりも少ないと十分な画像濃度が得にくく、１．５ｍｇ／ｃｍ²よりも多くなると個々のトナー粒子全てを均一に摩擦帯電することが難しくなり、カブリ抑制の悪化の要因となる。さらに、０．２ｍｇ／ｃｍ²以上０．９ｍｇ／ｃｍ²以下がより好ましい。
【０１５０】
トナーコート量は現像ブレード１０１により制御されるが、この現像ブレード１０１はトナー層を介してトナー担持体１０２に接触している。この時の接触圧は、５ｇ／ｃｍ以上５０ｇ／ｃｍ以下が好ましい範囲である。５ｇ／ｃｍよりも小さいとトナーコート量の制御に加え均一な摩擦帯電も難しくなり、カブリ抑制の悪化等の原因となる。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。
【０１５１】
トナーコート量の規制部材としては、トナーを圧接塗布するための弾性ブレード以外にも、金属ブレードあるいはローラ等を用いても良い。
【０１５２】
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が使用できる。また、それらの複合体であっても良い。
【０１５３】
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、金属弾性体に樹脂やゴムをスリーブ当接部に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。
【０１５４】
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、界面活性剤など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等の成型体の場合には、シリカ、アルミナ、チタニア、酸化錫、酸化ジルコニア、酸化亜鉛等の金属酸化物微粉末、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等を含有させることも好ましい。
【０１５５】
またさらに、規制部材に直流電場及び／または交流電場を印加することによっても、トナーヘのほぐし作用のため、均一薄層塗布性、均一帯電性がより向上し、充分な画像濃度の達成及び良質の画像を得ることができる。
【０１５６】
図３において、一次帯電部材１１０は矢印方向に回転する感光体１０９を一様に帯電する。ここで用いている一次帯電部材は、中心の芯金１１０ｂとその外周を形成した導電性弾性層１１０ａとを基本構成とする帯電ローラである。帯電ローラ１１０は、静電潜像担持体一面に押圧力を持って当接され、静電潜像担持体１の回転に伴い従動回転する。
【０１５７】
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、印加電圧としては直流電圧あるいは直流電圧に交流電圧を重畳したもの等が用いられ、特に限定されないが、本発明においては直流電圧のみの印加電圧が好適に用いられ、この場合の電圧値としては±０．２〜±５ｋＶの範囲で使用される。
【０１５８】
この他の帯電手段としては、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。これらの接触帯電手段は、非接触のコロナ帯電に比べて、高電圧が不必要になったり、オゾンの発生が低減するといった効果がある。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）などが適用可能である。
【０１５９】
一次帯電工程に次いで、発光素子からの露光１１１によつて感光体１０９上に情報信号に応じた静電潜像を形成し、トナー担持体１０２と当接する領域においてトナーにより静電潜像を現像し可視像化する。さらに、本発明の画像形成方法において、特に感光体上にデジタル潜像を形成した現像システムと組み合わせることで、潜像を乱さないためにドット潜像に対して忠実に現像することが可能となる。次に、該可視像を転写部材１０６により被転写体１０５上に転写し、更に転写トナー１１２は被転写体１０５と共に加熱ローラ１０８と加圧ローラ１０７の間を通過して定着され、永久画像を得る。なお、加熱加圧定着手段としては、ここに示したハロゲンヒーター等の発熱体を内蔵した加熱ローラとこれと押圧力をもって圧接された弾性体の加圧ローラを基本構成とする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用いられる。
【０１６０】
一方、転写されずに感光体１０９上に残った転写残トナー１１３は、感光体１０９と一次帯電部材１１０の間を通過して、再び現像ニップ部に到達し、トナー担持体１０２によって現像器１００内に回収される。
【０１６１】
【実施例】
以下、具体的実施例によって本発明を説明するが、本発明は何らこれに限定されるものではない。
【０１６２】
実施例１
高速撹拌装置ＴＫ式ホモミキサー（特殊機化工業製）を備えた２リットル用４つ口セパラブルフラスコ中に、イオン交換水３２５質量部と０．１ｍｏｌ／リットル−Ｎａ₃ＰＯ₄水溶液２５０質量部を投入し、回転数を１２０００ｒｐｍに調整し、７０℃に加温した。ここに１．０ｍｏｌ／リットル−ＣａＣｌ₂水溶液３５質量部を徐々に添加し、微小な難水溶性分散安定剤Ｃａ₃（ＰＯ₄）を含む水系連続相を調製した。
【０１６３】
一方、分散質として、
・化合物（１） １．０質量部
・２−エチルオクタデカン酸 ０．０６０質量部
・スチレン ８３質量部
・ｎ−ブチルアクリレート １７質量部
・ジビニルベンゼン（純度５５％） ０．１質量部
・カーボンブラック（ＢＥＴ比表面積＝８６ｍ² ／ｇ） ５質量部
・最大吸熱ピーク７０℃のパラフィンワックス ３質量部
・２，２’−アゾビス（２，４−ジメチルバレロニトリル） ５質量部
上記混合物をアトライター（三井三池化工製）を用い３時間分散したものを７０℃に加熱し、重合性単量体組成物を調製した。
【０１６４】
次に前記水系分散媒中に該重合性単量体組成物を投入し、窒素雰囲気下液温７０℃で高速攪拌機の回転数を１２０００ｒｐｍに維持しつつ１５分間撹拌し、該重合性単量体組成物を造粒した。その後、攪拌機をプロペラ型撹拌翼にかえて５０ｒｐｍで撹拌しながら７０℃で１０時間保持して懸濁液を得た。
【０１６５】
その後懸濁液を冷却し、次いで希塩酸を添加して分散安定剤を除去した。さらに水洗浄を数回繰り返した後乾燥し、粒子（１）を得た。該粒子についてＧＰＣにより分子量を測定したところ、メインピークの分子量が２．０万、Ｍｗが２７０万、Ｍｎが１．７万であった。
【０１６６】
上記粒子（１）１００質量部と疎水性シリカ微粉体（ＢＥＴ：１４０ｍ²／ｇ）０．９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。
【０１６７】
なお、トナー（１）の表面分析を前述のＩＲ／ＰＡＳにより分析したところ、２−エチルオクタデカン酸が検出された。
【０１６８】
実施例２
化合物（１）の仕込量を２．０質量部に変えた以外は実施例１と同様にして本発明の粒子（２）、トナー（２）を得た。
【０１６９】
実施例３
パラフィンワックスの仕込量を２０質量部に変えた以外は実施例１と同様にして本発明の粒子（３）、トナー（３）を得た。
【０１７０】
実施例４
２−エチルオクタデカン酸の仕込量を０．１７０質量部に変えた以外は実施例１と同様にして本発明の粒子（４）、トナー（４）を得た。
【０１７１】
実施例５
反応容器にキシレン２００質量部を入れ還流温度まで昇温した。これにスチレン８３質量部、アクリル酸−ｎ−ブチル１７質量部、及び、ジ−ｔｅｒｔ−ブチルパーオキサイド２．０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。
【０１７２】
一方、スチレン６７質量部、アクリル酸ブチル２５質量部、マレイン酸モノブチル８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０．３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。
【０１７３】
該高分子量樹脂２５質量部を、前記の低分子量樹脂７５質量部を含有する溶液重合終了時の溶液中に投入し、溶媒中に完全に溶解せしめ混合を行い、その後、溶媒を留去して結着樹脂（１）を得た。
【０１７４】
該結着樹脂（１）を分析したところ、低分子量側ピーク分子量は９０００、高分子量側ピーク分子量は７３００００、重量平均分子量（Ｍｗ）は４０００００、数平均分子量（Ｍｎ）は５２０００であった。
【０１７５】
次に、下記の各材料をブレンダーにて混合し、これを１５０℃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。
・結着樹脂（１） １００質量部
・化合物（１） ２．０質量部
・２−ブチルドデカン酸 ０．１０質量部
・カーボンブラック（ＢＥＴ比表面積＝９８ｍ² ／ｇ） ５質量部
・最大吸熱ピーク１１５℃の低分子量ポリエチレン ２質量部
【０１７６】
次いで、得られた粒子の表面改質（球形化）処理を行い、その後分級して粒子（５）とした。該粒子（５）１００質量部と疎水性シリカ微粉体（ＢＥＴ：１６０ｍ²／ｇ）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（５）とした。
【０１７７】
実施例６
結着樹脂（１）の仕込量を７５質量部とし、ピーク分子量１．０万のエポキシ樹脂２５質量部をさらに加えた以外は実施例５と同様にして、本発明の粒子（６）およびトナー（６）を調製した。
【０１７８】
実施例７（参考例）
表面改質処理を行わない以外は実施例５と同様にして、粒子（７）およびトナー（７）を調製した。
【０１７９】
実施例８
結着樹脂（１）の仕込量を４０質量部とし、エポキシ樹脂をさらに６０質量部加えた以外は実施例５と同様にして、本発明の粒子（８）およびトナー（８）を調製した。
【０１８０】
実施例９
２−エチルオクタデカン酸の仕込量を０．０１０質量部にした以外は実施例１と同様にして、本発明の粒子（９）およびトナー（９）を調製した。
【０１８１】
実施例１０
化合物（１）にかえて化合物（２）を用いる以外は実施例１と同様にして、本発明の粒子（１０）およびトナー（１０）を調製した。
【０１８２】
比較例１
ＴＫ式ホモミキサーを備えた２リットル用４つ口セパラブルフラスコ中に１％ポリビニルアルコール水溶液６００質量部と硫酸ナトリウム１８質量部を投入し、回転数を１２０００ｒｐｍに調整し、７０℃に加温して水系連続相を調製した。
【０１８３】
一方、分散質として、
・化合物（１） １．０質量部
・スチレン ８３質量部
・ｎ−ブチルアクリレート １７質量部
・ジビニルベンゼン（純度５５％） ０．１質量部
・カーボンブラック（ＢＥＴ比表面積＝８６ｍ² ／ｇ） ５質量部
・最大吸熱ピーク７０℃のパラフィンワックス ３質量部
・２，２’−アゾビス（２，４−ジメチルバレロニトリル） ５質量部
上記混合物をアトライター（三井三池化工製）を用い３時間分散したものを７０℃に加熱し、重合性単量体組成物を調製した。
【０１８４】
次に前記水系分散媒中に該重合性単量体組成物を投入し、窒素雰囲気下液温７０℃で高速攪拌機の回転数を１２０００ｒｐｍに維持しつつ１５分間撹拌し、該重合性単量体組成物を造粒した。その後、攪拌機をプロペラ型撹拌翼にかえて５０ｒｐｍで撹拌しながら７０℃で１０時間保持して懸濁液を得た。
【０１８５】
その後懸濁液を冷却し、次いで濾過／水洗浄を数回繰り返した乾燥し、比較用粒子（１）を得た。なお、濾過を行った際、濾液が焦げ茶色に着色していることが観察された。
【０１８６】
上記比較用粒子（１）１００質量部と疎水性シリカ微粉体（ＢＥＴ：１４０ｍ²／ｇ）０．９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（１）とした。
【０１８７】
比較例２
水系連続相として１％ポリビニルアルコール水溶液を用いる代わりに、１００ｐｐｍのドデシル硫酸ナトリウムを含む水６００質量部を用いた以外は比較例１と同様にして比較用粒子（２）、比較用トナー（２）を調製した。なお、濾過を行った際、濾液が赤茶色に着色していることが観察された。
【０１８８】
比較例３
化合物（１）の代わりに下記クロム系化合物（ｉ）を用いた以外は実施例１と同様にして比較用粒子（３）、比較用トナー（３）を調製した。なお、該粒子についてＧＰＣにより分子量を測定したところ、メインピークの分子量が１．４万、Ｍｗが９００万、Ｍｎが１．２万であった。
【０１８９】
【化１５】

【０１９０】
ＮＭＲおよび蛍光Ｘ線分析により、トナー（１）〜（１０）および比較用トナー（１）〜（３）中に含まれる化合物（１），（２）および炭素数６乃至４０の脂肪酸の量を測定した。円相当個数平均径、個数基準における全粒子数に対する２μｍ以下の粒子の割合（個数％）、平均円形度、円形度標準偏差の結果とともに表１に示す。
【０１９１】
【表１】

【０１９２】
実施例１１〜２０（但し、実施例１７は参考例である。）および比較例４〜６
上記実施例１〜１０及び比較例１〜３で製造したトナー（１）〜（１０）及び比較トナー（１）〜（３）を用い以下の通り評価を行った。
【０１９３】
図１に示す画像形成装置の現像装置を、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２．０倍となるように設定した。次に現像機内にトナー（１）〜（１０）および比較用トナー（１）〜（３）の各々を充填して、現像器を画像形成装置にセットし、常温常湿（２５℃，６０％ＲＨ）環境下、１２枚／分（Ａ４サイズ）のプリントアウト速度で、「電驚」文字パターンを連続１００枚、ベタ黒画像、ベタ白画像を各２枚、その後再び「電驚」文字パターンを連続３０００枚プリントアウトし、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。また、１００枚プリントアウト後とプリントアウト終了時のトナー担持体面上のトナーの帯電量変化量を測定した。
【０１９４】
以上の評価結果を表２にまとめる。
【０１９５】
なお、ここで用いたトナー担持体の表面粗度Ｒａは１．５であり、トナー規制ブレードの材質はステンレスである。
【０１９６】
【表２】

【０１９７】
実施例２１および比較例７
図２の画像形成装置を用いて、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２．５倍となるように設定し、次に現像器内にトナー（１）と比較用トナー（３）を充填し、現像器を画像形成装置にセットした。常温常湿（２５℃，６０％ＲＨ）環境下、単色モード，１２枚／分（Ａ４サイズ）のプリントアウト速度で、「電驚」文字パターンを連続１００枚、ベタ黒画像、ベタ白画像を各２枚、その後再び「電驚」文字パターンを連続３０００枚プリントアウトし、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。また、１００枚プリントアウト後とプリントアウト終了時のトナー担持体面上のトナーの帯電量変化量を測定した。
【０１９８】
なお、加熱定着装置には図５及び６に示した定着装置を用い、加熱体３１の検温素子３１ｄの表面温度は１９０℃，加熱体２１−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３３間の総圧は８８．２Ｎ（９ｋｇｆ）、加圧ローラとフィルムのニップは８ｍｍとし、定着フィルム３２には、転写材との接触面にＰＴＥＦ（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した。
【０１９９】
以上の評価結果を表３にまとめる。
【０２００】
なお、ここで用いたトナー担持体の表面粗度Ｒａは１．４であり、トナー規制ブレードの材質はステンレスである。
【０２０１】
【表３】

【０２０２】
実施例２２〜３１（但し、実施例２８は参考例である。）および比較例８〜１０
電子写真装置として６００ｄｐｉレーザービームプリンタ（キヤノン製：ＬＢＰ−８６０）を用意した。プロセススピードは、６０ｍｍ／ｓに改造してある。
【０２０３】
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はずし、装置の帯電方式をゴムローラを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。
【０２０４】
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。トナー供給体である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 Ｃ４５度，抵抗１０⁵Ω・ｃｍ）をトナー担持体とし、感光体に当接した。この時の現像ニップ幅は約３ｍｍとなるようにした。該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、該感光体回転周速に対し１４０％となるように駆動する。
【０２０５】
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、感光体を作製した。
【０２０６】
（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１５μｍ。
【０２０７】
（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。
【０２０８】
（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。
【０２０９】
（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４０μｍ。
【０２１０】
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、該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、該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。また、現像時の印加電圧をＤＣ成分（−４５０Ｖ）のみとした。
【０２１１】
これらのプロセスカートリッジの改造に適合するよう電子写真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。
【０２１２】
改造された装置はローラ帯電器（直流のみを印加）を用い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＋７００Ｖ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。また、感光体帯電電位は、暗部電位を−５８０Ｖとし、明部電位を−１５０Ｖとした。
【０２１３】
次に現像器内にトナー（１）〜（１０）と比較用トナー（１）〜（３）の各々を充填し、現像器を画像形成装置にセットした。常温常湿（２５℃，６０％ＲＨ）環境下、１６枚／分（Ａ４サイズ）のプリントアウト速度で、「電驚」文字パターンを連続１００枚、ベタ黒画像、ベタ白画像を各２枚、その後再び「電驚」文字パターンを連続３０００枚プリントアウトし、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。また、１００枚プリントアウト後とプリントアウト終了時のトナー担持体面上のトナーの帯電量変化量を測定した。
【０２１４】
以上の評価結果を表４にまとめる。
【０２１５】
【表４】

【０２１６】
本発明の実施例並びに比較例中に記載の評価項目の説明とその評価基準について述べる。
【０２１７】
［アウトプット画像評価］
＜１＞画像濃度
１０１枚目のベタ黒画像の画像濃度により評価した。なお、画像濃度は「マクベス反射濃度計」（マクベス社製）を用いて、原稿濃度が０．００の白地部分のプリントアウト画像に対する相対濃度を測定した。
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
【０２１８】
＜２＞カブリ
「リフレクトメーター」（東京電色社製）により測定した１０３枚目のベタ白画像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。
Ａ：１．５％未満
Ｂ：１．５％以上３．０％未満
Ｃ：３．０％以上５．０％未満
Ｄ：５．０％以上
【０２１９】
＜３＞中抜け
プリントアウト試験における最終ページの画像において、図４に示した「驚」文字パターンの文字の中抜けを目視で評価した。
Ａ：中抜けはほとんど発生せず。
Ｂ：軽微な中抜けが見られる。
Ｃ：若干の中抜けが見られる。
【０２２０】
【発明の効果】
本発明によれば、帯電の立ち上がりが良好で、プリントアウト速度を変化させた場合においても安定した帯電性を有し、高品質の画像の得られる乾式トナー及び画像形成方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の実施例に用いた一成分現像用の現像装置の要部の拡大横断面図である。
【図２】中間転写ベルトを用いたカラー画像出力装置の概略図である。
【図３】本発明の実施例で用いた画像形成装置の概略図である。
【図４】文字画像の中抜けの状態を示す模式図である。
【図５】本発明の実施例に用いた定着装置の要部の分解斜視図である。
【図６】本発明の実施例に用いた定着装置の非駆動時のフィルム状態を示した要部の拡大横断面図である。
【図７】本発明に係るトナーの断層面の模式図である。
【符号の説明】
１ 感光体（静電潜像担持体）
２ 帯電ローラ
３ 露光
３０ ステー
３１ 加熱体
３１ａ ヒーター基板
３１ｂ 発熱体
３１ｃ 表面保護層
３１ｄ 検温素子
３２ 定着フィルム
３３ 加圧ローラ
３４ コイルばね
３５ フィルム端部規制フランジ
３６ 給電コネクター
３７ 断電部材
３８ 入口ガイド
３９ 出口ガイド（分離ガイド）
４０ 中間転写体
４１ イエロー色現像装置
４２ マゼンタ色現像装置
４３ シアン色現像装置
４４ ブラック色現像装置
５１ 給紙ローラ
５２ 転写残トナークリーニング装置
５３ クリーニング装置
５５ 定着器
６２ 一次転写ローラ
６３ 二次転写ローラ
６４ 二次転写対向ローラ
６５ 中間転写ベルト支持ローラ
６６ 中間転写ベルト支持ローラ
１００ 現像装置
１０２ トナー担持体
１０４ トナー
１０５ 転写材
１０６ 転写部材
１０９ 感光体（静電荷像担持体）
１１０ 一次帯電部材
Ｐ 転写材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry toner (hereinafter referred to as 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. It is. 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]
Conventionally, as an electrophotographic method, many methods are known as described in US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, and the like. In general, a photoconductive substance is used, and an electric latent image is formed on the photoreceptor by various means, and then the latent image is developed with toner, and a direct or indirect means is used as necessary. Used to transfer a toner image onto a transfer material such as paper, and then fix it by heating, pressing, or solvent vapor to obtain a copy, etc., and untransferred toner that remains without being transferred onto the photoreceptor Is cleaned in various ways and the above steps are repeated.
[0003]
An example of a general method for forming a full-color image will be described. A photoreceptor (electrostatic latent image carrier) of a photoreceptor drum is uniformly charged by a primary charger, and is modulated by a magenta image signal of an original. Image exposure is performed with the laser beam, an electrostatic latent image is formed on the photosensitive drum, and the electrostatic latent image is developed by a magenta developing device having magenta toner, thereby forming a magenta toner image. Subsequently, the magenta toner image developed on the photosensitive drum by the transfer charger is transferred to the transferred transfer material directly or indirectly using a transfer charger.
[0004]
On the other hand, the photosensitive drum after the development of the electrostatic latent image is neutralized by a neutralizing charger, cleaned by a cleaning unit, and then charged by a primary charger again. The cyan toner image is formed on the transfer material onto which the magenta toner image has been transferred, and the toner images of four colors are transferred to the transfer material in the same manner as yellow and black. The transfer material having the four color toner images is fixed by the action of heat and pressure by a fixing roller, thereby forming a full color image.
[0005]
In recent years, such devices have been used not only in office copy machines for copying original documents, but also in the fields of laser beam printers (LBP) as computer output or personal copy (PC) for individuals. I started.
[0006]
In addition to the fields represented by LBP and PC, the development of plain paper fax machines using basic engines is also rapidly developing.
[0007]
As a result, smaller, lighter and faster speeds, higher image quality, and higher reliability are being sought after, and machines are becoming simpler in various ways. As a result, the performance required for the toner becomes higher, and if the improvement in the performance of the toner cannot be achieved, a better machine cannot be realized. In recent years, the demand for color copying has been increasing rapidly due to various copying needs, and further higher image quality and higher resolution are desired in order to copy original color images more faithfully. Furthermore, there is an increasing demand for copying original color originals on both sides.
[0008]
From these viewpoints, the toner used in the color image forming method must have good meltability and color mixing when heated, and has a low softening point and a low melt viscosity. It is preferable to use a high toner.
[0009]
That is, by using such sharp melt toner, it is possible to widen the color reproduction range of the copy and obtain a color copy faithful to the original image.
[0010]
However, such a color toner having a high sharp melt property generally has a high affinity with the fixing roller, and tends to be offset to the fixing roller during fixing.
[0011]
In particular, in the case of a fixing device in a color image forming apparatus, since a plurality of toner layers of magenta, cyan, yellow, and black are formed on a transfer material, an offset tends to easily occur due to an increase in toner layer thickness.
[0012]
Conventionally, for the purpose of preventing toner from adhering to the surface of the fixing roller, for example, the roller surface is coated with a material excellent in releasability with respect to the toner, such as silicone rubber or fluorine resin, and further, the surface is prevented from being offset, and In order to prevent the roller surface from being fatigued, the roller surface is coated with a thin film of a liquid having high releasability such as silicone oil or fluorine oil. However, this method is extremely effective in preventing toner offset, but has a problem that the fixing device is complicated because an apparatus is required to supply the liquid for preventing offset. Needless to say, this application of oil causes a delamination between the layers constituting the fixing roller, resulting in an adverse effect of promoting the shortening of the life of the fixing roller.
[0013]
Therefore, instead of using a silicone oil supply device, instead of supplying an offset prevention liquid from the toner during heating, there is a method of adding a release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner. Proposed.
[0014]
For example, Japanese Patent Publication No. 52-3304, Japanese Patent Publication No. 52-3305, Japanese Patent Laid-Open No. 57-52574, and the like have disclosed a technique for incorporating a wax as a releasing agent in the toner.
[0015]
JP-A-3-50559, JP-A-2-79860, JP-A-1-109359, JP-A-62-1166, JP-A-61-273554, JP-A-61-94062. JP-A-61-138259, JP-A-60-252361, JP-A-60-252360, JP-A-60-217366, etc. disclose techniques for containing waxes. Yes.
[0016]
Waxes are used to improve the offset resistance of toner at low and high temperatures, and to improve fixability at low temperatures. When exposed to heat due to temperature rise or the like, or when the toner is left for a long time, the wax migrates to the toner surface and developability deteriorates.
[0017]
In view of these problems, the expectation for development of a new toner has been great.
[0018]
A suspension polymerization toner has been proposed for the above problem (Japanese Patent Publication No. 36-10231). In this suspension polymerization method, a monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives). Then, the monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and simultaneously subjected to a polymerization reaction, whereby toner particles having a desired particle size are obtained. Is what you get.
[0019]
In this suspension polymerization method, droplets of the monomer composition are generated in a dispersion medium having a large polarity such as water. Therefore, the component having a polar group contained in the monomer composition is an interface with the aqueous phase. Therefore, it is possible to form a so-called core / shell structure in which a nonpolar component is not easily present in the surface layer portion. That is, the toner produced by the polymerization method can achieve the conflicting performances of low temperature fixing property, blocking resistance and durability, and high temperature offset resistance by encapsulating the wax component as a release agent, and a fixing roller. It is possible to prevent high temperature offset without applying a release agent such as oil.
[0020]
By the way, the toner generally contains a binder resin, which is a thermoplastic resin, and a colorant as essential components, and various binder resins have been improved for the purpose of improving the developability, fixability, storage stability, environmental stability, etc. of the toner. A method has been proposed. For example, with respect to the toner by the polymerization method described above, there is a method in which the outer shell of a resin having a relatively low glass transition temperature (Tg) is covered with a resin having a relatively high Tg in order to achieve both low-temperature fixability and storage stability. It has been proposed (for example, JP-A-5-197203). However, the resin having a relatively high Tg used in this case is often a polar resin having a hygroscopic property such as polyester, and even if both low temperature fixability and storage stability are possible, charging due to environmental fluctuations is possible. There may be problems with stability.
[0021]
Japanese Patent Application Laid-Open No. 7-248644 discloses a method for producing a polymerization toner using “T-77” (manufactured by Hodogaya Chemical Co.), which is an azo-based iron complex, as a charge control agent. However, in this publication, it is essential to use amorphous polyester, which is a hydrophilic material, as an outer shell material of toner particles, and it is possible to achieve both low-temperature fixability and storage stability to some extent. There was a problem with the charging stability. In addition, the toner according to the publication does not contain a wax component and does not contain a fatty acid, and there is room for improvement in terms of fixability and charge rising property.
[0022]
Further, JP-A-2-223960 discloses a method for producing a toner by a polymerization method using an azo complex whose central metal is chromium as a charge control agent and potassium oleate as a suspension stabilizing aid. . However, this publication does not describe an azo complex in which the central metal is iron, and does not describe any synergistic action and effect by using a fatty acid and an azo iron complex as toner raw materials.
[0023]
Japanese Patent Laid-Open Nos. 6-157619 and 6-282108 disclose polymerized toners using an azo-based iron complex as a charge control agent. However, in this gazette, the toner also contains a fatty acid. The effect by this is not shown at all. Further, since the suspension stabilizer is polyvinyl alcohol that elutes the azo-based iron complex into water as a continuous phase during the polymerization, there is a problem in the chargeability of the obtained toner.
[0024]
As described above, in recent years, there has been a great demand for users to copy originals on both sides or to make double-sided originals on both sides, and for this reason, both images with higher image quality and higher reliability are required. .
[0025]
Among various problems in the conventional color double-sided technology, one of the most important issues is paper curl that occurs after fixing one side. If the paper curl is large, the transportability of the fixed image is remarkably inferior, and an image with high image quality and high reliability cannot be obtained. On the other hand, the performance required for the toner is, for example, how to obtain a high-quality image satisfying image density, color reproducibility, etc. in a state where the amount of toner transferred to the transfer material is small. . For this purpose, it is necessary to improve the coloring power of the toner itself. Further, since an image passing through the fixing device twice is generated on both sides, further improvement in high temperature offset resistance is also required.
[0026]
Conventionally, in a full-color copying machine, four photoreceptors and a belt-like transfer belt are used, and an electrostatic latent image formed on each photoreceptor is developed with cyan, magenta, yellow, and black toners, and then the photoreceptor and After transferring the transfer material between the belt transfer bodies and transferring between straight paths, a full color image is formed, or the transfer material is wound around the surface of the transfer body facing the photosensitive member by mechanical action such as electrostatic force or gripper, A method of obtaining a full-color image as a result of performing the development-transfer process four times is generally used.
[0027]
In recent years, there has been an increasing need for various materials to be applied to small-size paper such as cardboard, cards, and postcards in addition to normal paper and overhead projector film (OHP) as full-color copying materials. In the method using the four photoconductors described above, since the transfer material is conveyed straight, the application range to various transfer materials is wide. However, it is necessary to accurately superimpose a plurality of toner images on the position of a predetermined transfer material. However, there is a problem that it is difficult to obtain a high-quality image with high reproducibility even with a slight difference in registration, and the transfer material conveyance mechanism becomes complicated, leading to a decrease in reliability and an increase in the number of parts. In addition, when using thick paper with a large amount of weight by adsorbing and winding the transfer material on the surface of the transfer body, the trailing edge of the transfer material causes poor adhesion due to the stiffness of the transfer material, resulting in an image based on transfer. It causes defects and is not preferable. Similarly, image defects may occur on small-size paper.
[0028]
For example, a full-color image device using a drum-shaped intermediate transfer member is proposed in US Pat. No. 5,187,526. However, U.S. Pat. No. 5,187,526 does not specifically describe the shape and configuration of toner particles.
[0029]
Further, Japanese Patent Application Laid-Open No. 59-125739 discloses a recording method in which a toner image formed with toner having an average particle diameter of 10 μm or less is transferred to an intermediate transfer member, and the toner image on the intermediate transfer member is further transferred to a transfer material. In addition, as a method for producing a toner, a method for directly producing toner particles using a suspension polymerization method is described. However, the transfer process described in Japanese Patent Application Laid-Open No. 59-125739 is a transfer using pressure transfer or adhesive transfer, and the surface of the intermediate transfer member is easily contaminated during the endurance of a large number of sheets. This is completely different from the transfer process in which the toner image is transferred mainly using the electric attractive force.
[0030]
Further, Japanese Patent Application Laid-Open No. 59-50473 has a heat-resistant elastic layer and a surface layer formed of an addition polymerization type silicone rubber on the surface of a support where a toner image on an image carrier is heated to a predetermined temperature. An electrostatic recording method or an electrophotographic copying method is described in which the toner image is transferred to an intermediate transfer member and the toner image on the intermediate transfer member is further transferred to a transfer material. However, in the image forming method described in JP-A-59-50473, the image carrier in contact with the heated intermediate transfer member is likely to deteriorate. Japanese Laid-Open Patent Publication No. 59-50473 does not describe a transfer process using an intermediate transfer body to which a voltage is applied.
[0031]
[Problems to be solved by the invention]
An object of the present invention is to provide a dry toner having good charge rise and stable chargeability even when the printout speed is changed, a method for producing the dry toner, and an image forming method using the toner. It is.
[0032]
[Means and Actions for Solving the Problems]
  The present invention is a dry toner containing at least a binder resin, a colorant and a wax, and the toner further contains a compound represented by the following general formula (1) and a fatty acid having 10 to 30 carbon atoms.,
  The wax is a compound different from the fatty acid;
  The content of the fatty acid is 30 to 3000 ppm and the content of the wax is 0.5 to 30% by mass with respect to the toner.
  FIn the toner-based number equivalent circle diameter-circularity scattergram measured by the raw particle image measuring device, the number equivalent particle diameter D1 (μm) of the toner is 2 to 10 μm and the average circularity And a circularity standard deviation of less than 0.050.
[0033]
[Chemical 6]

[0034]
The present invention also relates to a method for producing the toner.
[0035]
Furthermore, the present invention relates to an image forming method using the toner.
[0036]
As a result of intensive studies, the inventors of the present invention have the toner having the compound of the above general formula (1) and the fatty acid, so that the rising of charging is good and the charging property is stable even when the printout speed is changed. The inventors have found that a dry toner having the above can be obtained, and have completed the present invention.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
[0038]
The dry toner according to the present invention includes at least a binder resin, a colorant, and a wax component, and the toner includes a compound represented by the following general formula (1) and a carbon number represented by the following general formula (2). It is essential to contain 6 to 40 fatty acids.
[0039]
[Chemical 7]

[0040]
[Chemical 8]
General formula (2)

[Where R₇Represents a saturated or unsaturated hydrocarbon having 5 to 39 carbon atoms. ]
[0041]
Typical examples of the compound represented by the general formula (1) used in the present invention include the following compounds.
[0042]
[Chemical 9]

[0043]
[Chemical Formula 10]

[0044]
Embedded image

[0045]
Embedded image

[0046]
Embedded image

[0047]
Embedded image

[0048]
The content of the compound represented by the general formula (1) used in the present invention is 0.1 to 10% by mass, more preferably 0.2 to 2% by mass based on the toner particles, and deviates from this range. In addition, the excellent charge rising property of the present invention is hardly exhibited.
[0049]
Examples of the fatty acid having 6 to 40 carbon atoms used in the present invention include caprylic acid, nonanoic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, 2- Examples include methyldodecanoic acid, 2-methyltetradecanoic acid, 2-methylhexadecanoic acid, 2-methyloctadecanoic acid, 2-ethyldodecanoic acid, 2-butyldodecanoic acid, 2-ethyloctadecanoic acid, and behenic acid. However, among these, fatty acids having 10 to 30 carbon atoms can obtain particularly good chargeability. These fatty acids may be substituted with, for example, a halogen atom.
[0050]
The amount of the fatty acid used in the present invention is preferably 30 to 3000 ppm with respect to the toner. If the amount is less than this, the effect of improving the chargeability may not be exhibited. May occur. Further, the particularly preferable amount of the fatty acid is 100 to 1000 ppm, and by making it within this range, more stable charging property is expressed.
[0051]
Further, the qualitative / quantitative analysis of the compound of formula (1) and the fatty acid in the toner of the present invention can be performed using any conventionally known analysis means. For example, the toner may have a nuclear magnetic resonance spectrum (¹H-NMR,¹³C-NMR), infrared absorption spectrum (IR), Raman spectrum, ultraviolet absorption spectrum (UV), mass spectrum (MS) and other spectral analysis, elemental analysis, fluorescent X-ray, gas chromatography (GC), liquid chromatography Analysis may be performed by various methods such as (HPLC) and other chemical analyses. If the analysis is difficult with the toner itself, the toner may be Soxhlet extracted with a solvent that dissolves the binder resin such as tetrahydrofuran and toluene, and the residue and the filtrate may be analyzed separately. Further, these analysis means can be used alone or in combination as necessary.
[0052]
The fatty acid is more preferably at least partially present on the surface of the toner particles of the present invention, and the presence of the fatty acid on the surface facilitates quick chargeability.
[0053]
The analysis of the toner particle surface of the present invention can be carried out using any analysis means. For example, by using photoacoustic spectroscopy (PAS = Photoacoustic Spectroscopy) and changing the scanning speed of the movable mirror, the composition of the obtained toner particle surface can be analyzed by infrared absorption spectrum (IR / PAS). . In this way, it can be confirmed whether or not the fatty acid used in the present invention is present on the toner particle surface. In addition to IR / PAS, composition analysis of the toner surface combining Raman spectroscopy and the above PAS, elemental analysis of the toner surface by ESCA (Electron Spectroscopy for Chemical Analysis), energy dispersive X-ray spectrometer and electron beam energy There are various analysis means such as elemental analysis of the toner surface by an electron microscope equipped with an analyzer. These analysis means are used alone or in combination as necessary.
[0054]
Examples of the wax component used in the toner of the present invention 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, Includes oxides, block copolymers with vinyl monomers, and graft-modified products. In addition, various higher fatty acids and their metal salts, higher aliphatic alcohols, higher aliphatic esters, aliphatic amide waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, mineral waxes, petrolactams, etc. Things.
[0055]
These wax components have a maximum endothermic peak in the region of 40 to 150 ° C. at the time of temperature rise in the DSC curve measured by a differential differential 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 deterioration of high temperature offset resistance and excessive gloss. On the other hand, when the maximum endothermic peak exceeds 150 ° C., the fixing temperature becomes high and it becomes difficult to appropriately smooth the surface of the fixed image. It is not preferable. Further, when granulating / polymerizing in an aqueous medium and directly obtaining a toner by the polymerization method, if the maximum endothermic peak temperature is high, problems such as precipitation of a wax component mainly during granulation are not preferable. Therefore, it is particularly preferable to use a wax having an endothermic peak in the range of 50 to 100 ° C. from the viewpoint of obtaining low-temperature fixability and a high-quality image.
[0056]
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 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.
[0057]
In the present invention, the addition amount of these wax components is not particularly limited, but is preferably in the range of 0.5 to 30% by mass with respect to the toner.
[0058]
There are various methods for producing the toner according to the present invention. For example, when the toner is produced by a pulverization method, the compound represented by the general formula (1) and the fatty acid represented by the general formula (2) are used. , Binder resin, wax component, colorant and / or magnetic substance, charge control agent or other additives as required, mixed thoroughly by a mixer such as Henschel mixer, ball mill, etc. The target is collided with a target or under a jet stream and pulverized to a desired toner particle size. Thereafter, toner particles are smoothed and spheroidized as necessary. Next, the particle size distribution is sharpened through a classification step. Further, the toner of the present invention can be obtained by sufficiently mixing the classified powder with a fluidizing agent such as fine particle silica and a mixer such as a Henschel mixer. As another toner production method, a compound represented by the general formula (1) and / or a fatty acid represented by the general formula (2), which are finely powdered with a fluidizing agent or separately, are added to the classified powder. There is also a method in which the compound represented by the general formula (1) and the fatty acid represented by the general formula (2) are fixed to the toner surface, and in this case, the compound represented by the general formula (1) in the classified powder. Or a fatty acid represented by the general formula (2) may or may not be contained. Further, the toner particles may be smoothed and spheroidized after being fixed.
[0059]
Further, when the toner of the present invention is produced by a polymerization method, the monomer composition is previously incorporated with a compound represented by the general formula (1) or a fatty acid represented by the general formula (2), and For example, a method for directly producing a toner by using a suspension polymerization method as described in JP-A-36-10231, JP-A-59-53856, and JP-A-59-61842 can be employed. In addition, a polymer particle not containing the compound represented by the general formula (1) and / or the fatty acid represented by the general formula (2) is produced by a polymerization method, and then the fine particles are generally formed on the surface of the polymer particle. A method of applying a compound represented by formula (1) and / or a fatty acid represented by general formula (2), and smoothing and spheroidizing the particles as necessary, or represented by general formula (1) It is also possible to employ a method of seed polymerization of a monomer composition containing a compound and / or a fatty acid represented by the general formula (2). As another method, a melt containing a compound represented by the general formula (1) and a fatty acid represented by the general formula (2) using a disk or a multi-fluid nozzle described in JP-B-56-13945 Examples thereof include a method of atomizing the mixture in the air to obtain a spherical toner.
[0060]
Examples of the binder resin that can be used in the present invention include various resins such as generally used styrene-acrylic resins, polyester resins, and epoxy resins, and styrene-acrylic resins are particularly preferably used. These resins may be produced by any known method. For example, a styrene-acrylic resin can be obtained by polymerizing monomers for forming them. Specifically, styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, ( Meth) propyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Preferred are (meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, and ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide. Used. These are monomers alone or generally such that the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-p139-192 (manufactured by John Wiley & Sons) is 40-75 ° C. Are appropriately mixed and used. 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 is 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.
[0061]
In addition, other binder resins can be used in combination with the binder resin, and depending on the material, the outermost layer of the toner particles may be covered with another binder resin to improve storage stability and durability. Is possible. However, even when other binder resins are used in combination, the content of the styrene-acrylic resin is preferably in the range of 50 to 100% by mass, more preferably in the range of 80 to 100% by mass with respect to the total binder resin. If the content is less than 50% by mass, it becomes difficult to balance low-temperature fixability and developability.
[0062]
The molecular weight of the binder resin is measured by gel permeation chromatography (GPC). As a specific GPC measurement method, a solution obtained by dissolving a binder resin or toner in tetrahydrofuran (THF) at room temperature for 24 hours is filtered through a solvent-resistant membrane filter having a pore diameter of 0.2 μm to obtain a sample solution. And measured under the following conditions. In addition, sample preparation adjusts the quantity of THF so that the density | concentration of the component soluble in THF may be 0.4-0.6 mass%.
Apparatus: High-speed GPC HLC8120 GPC (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml
[0063]
In calculating the molecular weight of the sample, standard polystyrene resin (TSO standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- manufactured by Tosoh Corporation) was used. 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500).
[0064]
When the toner of the present invention is produced by a polymerization method, the molecular weight of the main peak in GPC of the binder resin of the obtained polymer particles is 3000 to 100,000, particularly preferably 5000 to 50000.
[0065]
The shape of the toner of the present invention is not particularly limited, but the following shapes are preferable in order to improve transferability and developability in a balanced manner. That is, the circle-equivalent number average diameter in the number-based particle size frequency distribution is 2 to 10 μm, the average circularity in the circularity frequency distribution is 0.920 to 0.995, preferably 0.950 to 0.995, By controlling the particle shape of the toner precisely so that the circularity standard deviation is preferably less than 0.060, preferably less than 0.050, more preferably less than 0.040, preferably 0.970 to 0.995. The transferability and developability can be improved in a well-balanced manner.
[0066]
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. The adhesion force to the body surface is increased, resulting in an increase in the residual toner.
[0067]
On the other hand, according to the present invention, even when the circle equivalent number average diameter is reduced to 2 to 10 μm, it is possible to reduce the abundance of the toner having a small particle diameter. The ratio of the number of particles of 2 μm or less relative to is usually less than 40% by number.
[0068]
By controlling the circularity standard deviation of the circularity frequency distribution and the abundance of the toner having a small particle diameter as described above, the stability of development property and transfer property against environmental fluctuations, and further durability are improved. The reason for this is that when the toner layer is formed on the toner carrier in the development process, the present inventors can maintain a sufficient toner coat amount even if the regulating force of the toner layer regulating member is stronger than usual. Therefore, the toner charge amount on the toner carrier can be made higher than usual without damaging the toner carrier.
[0069]
In addition, by controlling the average circularity of the circularity frequency distribution as described above, the transferability of toner having a small particle size, which has been difficult in the past, is greatly improved and the developing ability for low potential latent images is remarkably improved. To improve. This is particularly effective when developing a digital microspot latent image.
[0070]
The average circularity is particularly preferably 0.970 or more, and if it is less than this, the transferability may be deteriorated or the developability may be lowered. On the other hand, when the average circularity exceeds 0.995, the toner surface is remarkably deteriorated, resulting in problems in durability and the like.
[0071]
In the present invention, the equivalent-circle diameter, circularity, and frequency distribution of the toner are used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow type particle image measuring device FPIA- Measurement was performed using a 1000 model (manufactured by Toa Medical Electronics Co., Ltd.), and the calculation was performed using the following formula.
[0072]
[Expression 1]

[0073]
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.
[0074]
The circularity in the present invention is an index indicating the degree of unevenness of the toner particles, and indicates 1.00 when the toner particles are perfectly spherical. The more complicated the surface shape, the smaller the circularity.
[0075]
In the present invention, the circle-equivalent number average particle diameter D1 and the particle diameter standard deviation SDd, which mean the average value of the particle number frequency distribution based on the number of toners, are expressed as di (center value) at the dividing point i of the particle size distribution. , Frequency f_iThen, it is calculated from the following formula.
[0076]
[Expression 2]

[0077]

[0078]
[Equation 3]

[0079]
As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser UH-50 type (manufactured by SMT Co., Ltd.) equipped with a 5φ titanium alloy chip 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 this dispersion may not be 40 degreeC or more.
[0080]
To measure the shape of the toner particles, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 toner particles are obtained. Measure above. After the measurement, using this data, the equivalent circle diameter of the toner, the circularity frequency distribution, and the like are obtained.
[0081]
Examples of the colorant used in the present invention include the following yellow colorant, magenta colorant, and cyan colorant. The black colorant is carbon black, a magnetic material, or the following yellow colorant / magenta colorant / cyan. A mixture of colorants and toned to black is used.
[0082]
As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds, and the like 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, etc. are preferably used.
[0083]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.
[0084]
As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.
[0085]
These colorants can be used alone or in combination and further in the form of a solid solution. The colorant is selected from the viewpoints of hue, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner particles. The addition amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the resin component.
[0086]
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, or aluminum of these metals, cobalt, copper, lead, magnesium, tin, zinc, Examples include alloys of metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof.
[0087]
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.
[0088]
These magnetic materials have an average particle size of 2 μm or less, 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 resin. Further, the magnetic characteristics when 796 kA / m (10 k Oersted) is applied are coercive force (Hc) of 1.6 to 24 kA / m, and saturation magnetization (σs) of 50 to 200 Am.²/ Kg, residual magnetization (σr) 2-20 Am²/ Kg of magnetic material is preferred.
[0089]
As the charge control agent that can be used together with the general formula (1) in the present invention, a known charge control agent can be used, and in particular, a charge control agent that has a high charging speed and can stably maintain a constant charge amount is preferable. Further, when a direct polymerization method is used for toner particles, a charge control agent having no polymerization inhibitory property and having no solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include metal compounds of aromatic carboxylic acids such as salicylic acid, naphthoic acid and dicarboxylic acid as negative charge control agents; polymer compounds having a sulfonic acid or carboxylic acid group in the side chain; boron compounds; urea Compound; silicon compound; calixarene and the like. Examples of the positive charge control agent include quaternary ammonium salts; polymer type compounds having the quaternary ammonium salt in the side chain; guanidine compounds; imidazole compounds. The charge control agent is preferably used in an amount of 0.05 to 10 parts by mass with respect to 100 parts by mass of the resin.
[0090]
In the present invention, as a specific method for observing the tomographic plane of the toner, a cured product obtained by sufficiently dispersing toner particles in a room temperature curable epoxy resin and curing at 40 ° C. for 2 days is used. After staining with ruthenium oxide and, if necessary, osmium tetroxide, a sliced sample is cut out using a microtome equipped with diamond teeth, and the tomographic surface of the toner is observed using a transmission electron microscope. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to provide a contrast between materials by utilizing a slight difference in crystallinity between the wax component to be used and the binder resin constituting the outer shell. A representative example is shown in FIGS. 7a and 7b.
[0091]
When the toner particles (1) and (7) obtained in Examples 1 and 7 to be described later were observed on a tomographic surface with a TEM, in the case of toner particles (1), the wax component was substantially contained in the binder resin. In the case of toner particles (7), it was observed that the wax component was finely dispersed in the binder resin.
[0092]
When a polymerization method is used as a toner production method, the particle size distribution control and particle size control of the toner particles can be controlled by changing the type and amount of a poorly water-soluble inorganic salt or a dispersing agent that acts as a protective colloid or mechanically. Predetermined toner particles can be obtained by controlling the apparatus conditions (for example, the circumferential speed of the rotor, the number of passes, the stirring conditions such as the shape of the stirring blades and the container shape) or the solid content concentration in the aqueous solution.
[0093]
When the toner is produced by the direct polymerization method, examples of the polymerization initiator used include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1. Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide Peroxide-based polymerization initiators such as methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide are 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 is slightly different depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.
[0094]
In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor or the like may be further added and used.
[0095]
When a suspension polymerization method using a dispersion stabilizer is used as a toner production method, the dispersion stabilizer used is an inorganic compound such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, Examples thereof include magnesium carbonate, calcium hydroxide, 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, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salt, starch and the like. These can be used by dispersing in an aqueous phase. 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.
[0096]
When an inorganic compound is used as the dispersion stabilizer, a commercially available one may be used as it is, but in order to obtain fine particles, fine particles of the inorganic compound may be generated in a dispersion medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution may be mixed under high-speed stirring.
[0097]
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 above dispersion stabilizer, such as sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate. , Calcium oleate and the like.
[0098]
When the direct polymerization method is used as a method for producing the toner used in the present invention, the following production method is possible.
[0099]
A monomer composition in which a wax component, a colorant, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, etc. Disperse in an aqueous phase containing a dispersion stabilizer by a normal stirrer, homomixer, homogenizer or the like. Preferably, the monomer composition is granulated by adjusting the stirring speed and stirring time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is preferably carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. The temperature may be raised in the latter half of the polymerization reaction, and for the purpose of improving durability in the image forming method of the present invention, in order to remove the unreacted polymerizable monomer, by-products, etc., or After completion of the reaction, a part of the aqueous medium may be distilled off from the reaction system. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer composition.
[0100]
Next, an image forming method to which the toner of the present invention is applied will be described below with reference to the accompanying drawings.
[0101]
The toner of the present invention can be applied to various development methods. As an example, FIG. 1 shows an example of an apparatus for developing an electrostatic image formed on an electrostatic latent image carrier by one-component development, but is not necessarily limited thereto.
[0102]
In FIG. 1, reference numeral 25 denotes an electrostatic latent image carrier (photosensitive drum), and the latent image is formed by electrophotographic process means or electrostatic recording means. Reference numeral 24 denotes a toner carrier (developing sleeve), which is a non-magnetic sleeve made of aluminum, stainless steel or the like.
[0103]
The substantially right half circumferential surface of the developing sleeve 24 is always in contact with the toner reservoir in the toner container 21, and the toner near the developing sleeve surface is applied to the developing sleeve surface by the magnetic force of the magnetic generating means in the sleeve and / or electrostatic force. Adhesion is retained.
[0104]
In the present invention, the surface roughness Ra (μm) of the toner carrier is set to be 1.5 or less. Preferably it is 1.0 or less. More preferably, it is 0.5 or less.
[0105]
By controlling the surface roughness Ra to 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 toner Since the number of times of contact is increased, the chargeability of the toner is also improved, so that the image quality is synergistically improved.
[0106]
If the surface roughness Ra of the toner carrier exceeds 1.5, it is difficult not only to make the toner layer on the toner carrier thin, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. .
[0107]
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 JIS surface roughness “JIS B 0601”. This corresponds to 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 expressed by y = f (x), it means a value obtained by the following formula expressed in micrometers (μm).
[0108]
[Expression 4]

[0109]
As the toner carrier used in the present invention, for example, a cylindrical or belt-like member made of stainless steel, aluminum or the like is preferably used. If necessary, the surface may be coated with a metal, a resin, or the like, or a resin in which fine particles such as a resin, a metal, carbon black, or a charge control agent are dispersed may be coated.
[0110]
In the present invention, by setting the surface movement speed of the toner carrier to be 1.05 to 3.0 times the surface movement speed of the electrostatic latent image carrier, the toner layer on the toner carrier is Since it receives an appropriate stirring effect, the faithful reproduction of the electrostatic latent image is further improved.
[0111]
When the surface moving speed of the toner carrying member is less than 1.05 times the surface moving speed of the electrostatic latent image carrying member, the stirring effect received by the toner layer becomes insufficient, and good image formation cannot be expected. . In addition, 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. On the other hand, when it exceeds 3.0 times, in addition to the various problems caused by the excessive charging of the toner as described above, the deterioration of the toner due to mechanical stress and the toner fixing to the toner carrier are generated and promoted. It is not preferable.
[0112]
The toner T is stored in the hopper 21 and is supplied onto the developing sleeve by the supply member 22. As the supply member, a supply roller made of a foamed material such as a porous elastic body, for example, a flexible polyurethane foam is preferably used. The supply roller is rotated relative to the developing sleeve at a non-zero relative speed in the forward or reverse direction, and the toner (undeveloped toner) after development on the sleeve is peeled off along with the supply of toner onto the developing sleeve. . At this time, the contact width of the supply roller to the developing sleeve is preferably 2.0 to 10.0 mm, and more preferably 4.0 to 6.0 mm in consideration of the balance between toner supply and peeling. On the other hand, excessive stress on the toner is inevitably required, and the toner is likely to increase in aggregation due to toner deterioration or to be fused and fixed to the developing sleeve, supply roller, etc., but is used in the developing method of the present invention. Since the toner is excellent in fluidity and releasability and has durability stability, it is preferably used in a developing method having the supply member. Moreover, as a supply member, you may use the brush member which consists of resin fibers, such as nylon and rayon. These supply members are extremely effective in a one-component development method using a non-magnetic one-component toner that cannot use a magnetic binding force, but may be used in a one-component development method using a magnetic one-component toner.
[0113]
The toner supplied onto the developing sleeve is uniformly applied in a thin layer by the regulating member. The toner thinning restriction member is a doctor blade such as a metal blade or a magnetic blade that is disposed at a predetermined interval from the developing sleeve. Alternatively, instead of the doctor blade, a rigid roller or sleeve using metal, resin, ceramics, or the like may be used, and magnetism generating means may be used inside them.
[0114]
Further, an elastic body such as an elastic blade or an elastic roller for press-fitting toner may be used as a toner thinning regulating member. For example, in FIG. 1, the elastic blade 23 has a base portion, which is the upper side portion, fixed and held on the developer container 21 side, and a lower side portion is directed in the forward or reverse direction of the developing sleeve 24 against the elasticity of the blade. In the warped state, the inner surface side of the blade (the outer surface side in the reverse direction) is brought into contact with the surface of the sleeve 24 with an appropriate elastic pressure. According to such an apparatus, it is possible to obtain a dense toner layer that is stable against environmental changes. The reason is not necessarily clear, but it is presumed that charging is always performed in the same state regardless of a change in behavior due to an environmental change of the toner because the elastic body forcibly rubs against the surface of the developing sleeve.
[0115]
On the other hand, the toner tends to be excessively charged and the toner is likely to be fused on the developing sleeve or the elastic blade. However, the toner used in the present invention is preferably used because it has excellent releasability and stable tribocharging. It is done.
[0116]
For the elastic body, it is preferable to select a material of a triboelectric charge series suitable for charging the toner to a desired polarity. A rubber elastic body such as silicone rubber, urethane rubber or NBR, or a synthetic resin elastic body such as polyethylene terephthalate. Metal elastic bodies such as stainless steel, steel and phosphor bronze can be used. Moreover, those composites may be sufficient.
[0117]
Further, when durability is required for the elastic body and the toner carrying body, it is preferable that the metal elastic body is bonded or coated with a resin or rubber so as to contact the sleeve contact portion.
[0118]
Furthermore, an organic substance or an inorganic substance may be added to the elastic body, 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, surfactant or the like. In particular, when the elastic body is a molded body such as rubber or resin, fine metal oxide powders such as silica, alumina, titania, tin oxide, zirconia oxide and zinc oxide, carbon black, and a charge control agent generally used for toners Etc. are also preferably contained.
[0119]
Further, even when a DC electric field and / or an AC electric field is applied to the developing blade as the regulating member, the supply roller as the feeding member, and the brush member, the regulating member on the developing sleeve is uniform because of the loosening action on the toner. The thin-layer coating property and the uniform charging property are further improved, and the supply / peeling of the toner is more smoothly performed on the supply member, so that sufficient image density can be achieved and a high-quality image can be obtained.
[0120]
The contact pressure between the elastic body and the toner carrier is 0.1 kg / m or more, preferably 0.3 to 25 kg / m, more preferably 0.5 to 12 kg as a linear pressure in the generatrix direction of the toner carrier. / M is effective. As a result, it is possible to effectively relieve the suspicion of toner, and it is possible to instantly increase the toner charge amount. When the contact pressure is less than 0.1 kg / m, it is difficult to uniformly apply the toner, and the toner charge amount distribution becomes broad, causing fog and scattering. On the other hand, when the contact pressure exceeds 25 kg / m, a large pressure is applied to the toner, which is not preferable because the toner deteriorates or toner aggregates are generated. Further, it is not preferable because a large torque is required to drive the toner carrier.
[0121]
The gap α between the electrostatic latent image carrier and the toner carrier is preferably set to 50 to 500 μm, and the gap between the doctor blade and the toner carrier is preferably set to 50 to 400 μm.
[0122]
The layer thickness of the toner layer on the toner carrier is most preferably thinner than the gap α between the electrostatic latent image carrier and the toner carrier, but in some cases, among the many toner spikes constituting the toner layer, The thickness of the toner layer may be regulated so that a part of the toner layer contacts the electrostatic latent image carrier.
[0123]
On the other hand, an alternating electric field is applied to the toner carrier from the electrostatic latent image carrier by the bias power source 26 to facilitate movement of the toner from the toner carrier to the electrostatic latent image carrier. A good quality image can be obtained. Vpp of the alternating electric field is 100V or more, preferably 200 to 3000V, more preferably 300 to 2000V. Further, f is used at 500 to 5000 Hz, preferably 1000 to 3000 Hz, more preferably 1500 to 3000 Hz. As the waveform in this case, a rectangular wave, a sine wave, a sawtooth wave, a triangular wave or the like can be applied. Also, asymmetrical AC bias with different forward and reverse voltages and time can be used. It is also preferable to superimpose a DC bias.
[0124]
The electrostatic latent image carrier 25 is a-Se, Cds, ZnO.₂, OPC, a photosensitive drum or photosensitive belt having a photoconductive insulating material layer such as a-Si. The electrostatic latent image carrier 1 is rotated in the direction of the arrow by a driving device (not shown).
[0125]
As the electrostatic latent image carrier 25, an amorphous silicon photosensitive layer or a photosensitive member having an organic photosensitive layer is preferably used.
[0126]
The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation material and a substance having a charge transport function in the same layer, or a function-separated type photosensitive layer having a charge transport layer and a charge generation layer as components. It may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.
[0127]
Polycarbonate resin, polyester resin, and acrylic resin are the binder resins for the organic photosensitive layer, in particular, transferability and cleaning properties are good, and poor cleaning, toner fusion to the photoreceptor, and filming of external additives are unlikely to occur. .
[0128]
In the charging process, there are a non-contact method with the electrostatic latent image carrier 25 using a corona charger and a contact type method using a roller or the like, and any of them is used. The contact type is preferably used for efficient uniform charging, simplification, and low ozone generation.
[0129]
Next, FIG. 2 shows a schematic diagram of an example of an image forming apparatus using an intermediate transfer belt.
[0130]
FIG. 2 shows a color image forming apparatus (copier or laser beam printer) using an electrophotographic process.
[0131]
Reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) as a first image carrier, which is rotationally driven in the direction of an arrow at a predetermined peripheral speed (process speed).
[0132]
The photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by a primary charger 2 during the rotation process, and then subjected to exposure 3 by an image exposure means 3 (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.
[0133]
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 41). At this time, the second to fourth developing units, that is, the magenta developing unit 42, the cyan developing unit 43, and the black developing unit 44 are not operated and do not act on the photosensitive drum 1. The yellow component image of the color is not affected by the second to fourth developing units.
[0134]
The intermediate transfer belt 40 is driven to rotate in the direction of the arrow at the same peripheral speed as that of the photosensitive drum 1.
[0135]
In the process in which the yellow component image of the first color formed on the photosensitive drum 1 passes through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 40, the intermediate transfer belt is supplied from the bias power source 49 via the primary transfer roller 62. The image is sequentially transferred (primary transfer) to the outer peripheral surface of the intermediate transfer belt 40 by an electric field formed by a primary transfer bias applied to the belt 40.
[0136]
The surface of the photosensitive drum 1 after the transfer of the first color yellow toner image corresponding to the intermediate transfer belt 40 is cleaned by the first cleaning device 53.
[0137]
Similarly, the second color magenta toner image, the third color cyan toner image, and the fourth color black toner image are sequentially superimposed and transferred onto the intermediate transfer belt 40, and a composite color corresponding to the target color image is obtained. A toner image is formed.
[0138]
Reference numeral 63 denotes a secondary transfer roller, which is supported in parallel with the secondary transfer counter roller 64 and arranged in a state in which it can be separated from the lower surface of the intermediate transfer belt 40.
[0139]
A primary transfer bias for transferring the toner image from the photosensitive drum 1 to the intermediate transfer belt 40 is applied from a bias power source 49 with a polarity opposite to that of the toner. The applied voltage is, for example, in the range of +100 V to +2 kV.
[0140]
In the primary transfer process of the first to third color toner images from the photosensitive drum 1 to the intermediate transfer belt 40, the secondary transfer roller 63 and the residual transfer toner charging member 52 can be separated from the intermediate transfer belt 40. .
[0141]
The full-color image transferred onto the intermediate transfer belt 40 is contacted by the secondary transfer roller 63 with the intermediate transfer belt 40, and a predetermined portion is contacted between the paper feeding roller 51 and the intermediate transfer belt 40 and the secondary transfer roller 63. At this timing, the transfer material P as the second image carrier is fed, and the secondary transfer bias is applied from the bias power supply 48 to the secondary transfer roller 63 to be 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 55 and fixed by heating.
[0142]
After the image transfer to the transfer material P is completed, a transfer residual toner cleaning device 52 is brought into contact with the intermediate transfer belt 40 to clean the surface of the intermediate transfer belt 40.
[0143]
Next, a monochromatic image forming method using the cleanerless process will be described with reference to FIG.
[0144]
In FIG. 3, 100 is a developing device, 109 is a photosensitive member, 105 is a transfer member such as paper, 106 is a transfer member, 107 is a fixing pressure roller, 108 is a fixing heating roller, and 110 is in contact with the photosensitive member 109. A primary charging member that performs direct charging is shown.
[0145]
A bias power source 115 is connected to the primary charging member 110 so as to uniformly charge the surface of the photoconductor 109.
[0146]
The developing device 100 contains toner 104 and includes a toner carrier 102 that contacts the photoconductor 109 and rotates in the direction of the arrow. Further, a developing blade 101 for regulating the amount of toner and charging, and a coating roller 103 that rotates in the direction of the arrow in order to attach the toner 104 to the toner carrier 102 and to charge the toner by friction with the toner carrier 102 are also provided. I have. A developing bias power source 117 is connected to the toner carrier 102. A bias power supply 118 is also connected to the application roller 103, and a voltage is set on the negative side of the developing bias when negatively charged toner is used, and on the positive side of the developing bias when positively charged toner is used. Is done.
[0147]
A transfer bias power supply 116 having a polarity opposite to that of the photoconductor 109 is connected to the transfer member 106. Here, the length in the rotational direction at the contact portion between the photosensitive member 109 and the toner carrier 102, that is, the so-called development nip width is preferably 0.2 mm or more and 8.0 mm or less. 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 is not sufficiently collected. If it exceeds 8.0 mm, the amount of toner supplied becomes excessive, fog suppression is likely to deteriorate, and the wear of the photoreceptor is also adversely affected.
[0148]
As the toner carrier, a so-called elastic roller having an elastic layer on its surface is preferably used. The hardness of the material of the elastic layer used is preferably 20 to 65 degrees (JISA). The resistance of the toner carrier is 10 in terms of volume resistance.²-10⁹A range of about Ωcm is preferable. 10²If it is lower than Ωcm, for example, if there is a pinhole on the surface of the photoconductor 109, an overcurrent may flow. Conversely, 10⁹When it is higher than Ωcm, the toner is likely to be charged up by frictional charging, and the image density is likely to be lowered.
[0149]
The toner coat amount on the toner carrier is 0.1 mg / cm²1.5 mg / cm or more²The following is preferred. 0.1 mg / cm²If it is less than 1, it is difficult to obtain a sufficient image density, and 1.5 mg / cm²If it exceeds the upper limit, it becomes difficult to uniformly triboelectrically charge all of the individual toner particles, which causes deterioration of fog suppression. Furthermore, 0.2 mg / cm²0.9 mg / cm²The following is more preferable.
[0150]
The toner coating amount is controlled by the developing blade 101, and the developing blade 101 is in contact with the toner carrier 102 through the toner layer. The contact pressure at this time is preferably in the range of 5 g / cm to 50 g / cm. If it is less than 5 g / cm, in addition to controlling the toner coating amount, uniform frictional charging becomes difficult, which causes deterioration of fog suppression. On the other hand, if it exceeds 50 g / cm, the toner particles are subjected to an excessive load, so that deformation of the particles and fusion of the toner to the developing blade or the toner carrier are likely to occur.
[0151]
As the toner coating amount regulating member, a metal blade, a roller, or the like may be used in addition to the elastic blade for press-contacting the toner.
[0152]
It is preferable to select a frictional charging material suitable for charging the toner to a desired polarity for the elastic regulating member, such as a rubber elastic body such as silicone rubber, urethane rubber or NBR, or a synthetic resin elastic material such as polyethylene terephthalate. Body, metal elastic body such as stainless steel, steel and phosphor bronze can be used. Moreover, those composites may be sufficient.
[0153]
Further, when durability is required for the elastic regulating member and the toner carrying member, it is preferable that the metal elastic member is bonded or coated with a resin or rubber so as to contact the sleeve contact portion.
[0154]
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, surfactant or the like. In particular, when the elastic body is a molded body such as rubber or resin, fine metal oxide powders such as silica, alumina, titania, tin oxide, zirconia oxide and zinc oxide, carbon black, and a charge control agent generally used for toners Etc. are also preferably contained.
[0155]
Furthermore, by applying a DC electric field and / or an AC electric field to the regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening action on the toner, and sufficient image density can be achieved and a good quality can be achieved. An image can be obtained.
[0156]
In FIG. 3, the primary charging member 110 uniformly charges the photoconductor 109 rotating in the direction of the arrow. The primary charging member used here is a charging roller having a basic configuration of a central cored bar 110b and a conductive elastic layer 110a formed on the outer periphery thereof. The charging roller 110 is brought into contact with the entire surface of the electrostatic latent image carrier with a pressing force, and is rotated following the rotation of the electrostatic latent image carrier 1.
[0157]
As a preferable process condition when using a charging roller, the contact pressure of the roller is 5 to 500 g / cm, and the applied voltage is a DC voltage or a DC voltage superimposed with an AC voltage, and the like. However, in the present invention, an applied voltage of only a DC voltage is preferably used, and a voltage value in this case is used in a range of ± 0.2 to ± 5 kV.
[0158]
Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage is unnecessary and generation of ozone is reduced 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), and the like are applicable.
[0159]
Subsequent to the primary charging step, an electrostatic latent image corresponding to the information signal is formed on the photoconductor 109 by exposure 111 from the light emitting element, and the electrostatic latent image is developed with toner in an area in contact with the toner carrier 102. And visualized. Furthermore, in the image forming method of the present invention, particularly in combination with a developing system in which a digital latent image is formed on a photoreceptor, it becomes possible to develop the dot latent image faithfully without disturbing the latent image. . Next, the visible image is transferred onto the transfer target 105 by the transfer member 106, and the transfer toner 112 is further fixed together with the transfer target 105 through the heating roller 108 and the pressure roller 107. Get. Note that the heating and pressure fixing means is not limited to the heating roller system including a heating roller having a built-in heating element such as a halogen heater and an elastic pressing roller pressed against the heating roller. A system in which heat is fixed by a heater through a film is also used.
[0160]
On the other hand, the untransferred toner 113 that remains on the photosensitive member 109 without being transferred passes between the photosensitive member 109 and the primary charging member 110 and reaches the developing nip again, and is developed by the toner carrying member 102 by the developing device 100. Collected in.
[0161]
【Example】
Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.
[0162]
Example 1
In a 4-liter separable flask for 2 liters equipped with a high-speed stirring device TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.)_ThreePO_Four250 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 / liter-CaCl₂Gradually add 35 parts by weight of an aqueous solution to form a slightly poorly water-soluble dispersion stabilizer Ca_Three(PO_FourAn aqueous continuous phase containing) was prepared.
[0163]
On the other hand, as dispersoid,
Compound (1) 1.0 part by mass
・ 0.060 parts by mass of 2-ethyloctadecanoic acid
・ 83 parts by mass of styrene
・ 17 parts by mass of n-butyl acrylate
・ Divinylbenzene (purity 55%) 0.1 parts by mass
・ Carbon black (BET specific surface area = 86m² / G) 5 parts by mass
・ 3 parts by mass of paraffin wax with a maximum endothermic peak of 70 ° C.
・ 5 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile)
A dispersion of the above mixture using an attritor (manufactured by Mitsui Miike Chemical Industries) for 3 hours was heated to 70 ° C. to prepare a polymerizable monomer composition.
[0164]
Next, the polymerizable monomer composition is charged into the aqueous dispersion medium and stirred for 15 minutes while maintaining the rotation speed of a high-speed stirrer at 12000 rpm at a liquid temperature of 70 ° C. in a nitrogen atmosphere. The composition was granulated. Subsequently, the suspension was changed to a propeller-type stirring blade and held at 70 ° C. for 10 hours while stirring at 50 rpm to obtain a suspension.
[0165]
The suspension was then 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 particles (1). When the molecular weight of the particles was measured by GPC, the molecular weight of the main peak was 20,000, Mw was 2,700,000, and Mn was 17,000.
[0166]
100 parts by mass of the above particle (1) and hydrophobic silica fine powder (BET: 140 m²/ G) 0.9 part by mass was dry-mixed with a Henschel mixer to obtain toner (1) of the present invention.
[0167]
Incidentally, when the surface analysis of the toner (1) was analyzed by the above-mentioned IR / PAS, 2-ethyloctadecanoic acid was detected.
[0168]
Example 2
The particles (2) and toner (2) of the present invention were obtained in the same manner as in Example 1 except that the amount of the compound (1) charged was changed to 2.0 parts by mass.
[0169]
Example 3
The particles (3) and toner (3) of the present invention were obtained in the same manner as in Example 1 except that the amount of paraffin wax charged was changed to 20 parts by mass.
[0170]
Example 4
The particles (4) and toner (4) of the present invention were obtained in the same manner as in Example 1 except that the amount of 2-ethyloctadecanoic acid was changed to 0.170 parts by mass.
[0171]
Example 5
In a reaction vessel, 200 parts by mass of xylene was added and the temperature was raised to the reflux temperature. A solution mixture of 83 parts by mass of styrene, 17 parts by mass of acrylate-n-butyl and 2.0 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 low molecular weight resin solution was obtained.
[0172]
On the other hand, 67 parts by mass of styrene, 25 parts by mass of butyl acrylate, 8 parts by mass of monobutyl maleate, 0.2 parts by mass of polyvinyl alcohol, 200 parts by mass of deaerated water, and 0.3 parts by mass of benzoyl peroxide were mixed and dispersed. It was. 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.
[0173]
25 parts by weight of the high molecular weight resin is put into a solution at the end of the solution polymerization containing 75 parts by weight of the low molecular weight resin, completely dissolved in a solvent and mixed, and then the solvent is distilled off. Binder resin (1) was obtained.
[0174]
When the binder resin (1) was analyzed, the low molecular weight side peak molecular weight was 9000, the high molecular weight side peak molecular weight was 730000, the weight average molecular weight (Mw) was 400,000, and the number average molecular weight (Mn) was 52,000.
[0175]
Next, the following materials were mixed in a blender, melted and kneaded with a biaxial extruder heated to 150 ° C., the cooled kneaded product was coarsely pulverized with a hammer mill, and the coarsely pulverized product was then mixed with a jet mill. Finely pulverized.
・ Binder resin (1) 100 parts by mass
Compound (1) 2.0 parts by mass
・ 0.10 parts by mass of 2-butyldodecanoic acid
・ Carbon black (BET specific surface area = 98m² / G) 5 parts by mass
・ Low molecular weight polyethylene with a maximum endothermic peak of 115 ° C. 2 parts by mass
[0176]
Subsequently, the obtained particles were subjected to a surface modification (spheronization) treatment, and then classified into particles (5). 100 parts by mass of the particles (5) and fine hydrophobic silica powder (BET: 160 m²/ G) The toner (5) of the present invention was obtained by dry mixing 2 parts by mass with a Henschel mixer.
[0177]
Example 6
The particles (6) and toner of the present invention were the same as in Example 5 except that the amount of the binder resin (1) charged was 75 parts by mass, and 25 parts by mass of an epoxy resin having a peak molecular weight of 10,000 was further added. (6) was prepared.
[0178]
  Example 7 (reference example)
  Other than not performing surface modification treatmentExample 5Like,grainChild (7) and toner (7) were prepared.
[0179]
Example 8
The particles (8) and toner (8) of the present invention were prepared in the same manner as in Example 5 except that the amount of the binder resin (1) charged was 40 parts by mass and the epoxy resin was further added by 60 parts by mass.
[0180]
Example 9
Particles (9) and toner (9) of the present invention were prepared in the same manner as in Example 1 except that the amount of 2-ethyloctadecanoic acid was changed to 0.010 parts by mass.
[0181]
Example 10
The particles (10) and toner (10) of the present invention were prepared in the same manner as in Example 1 except that the compound (2) was used instead of the compound (1).
[0182]
Comparative Example 1
Into a 2 liter four-necked separable flask equipped with a TK type homomixer, 600 parts by mass of a 1% polyvinyl alcohol aqueous solution and 18 parts by mass of sodium sulfate were added, the rotation speed was adjusted to 12000 rpm, and the mixture was heated to 70 ° C. An aqueous continuous phase was prepared.
[0183]
On the other hand, as dispersoid,
Compound (1) 1.0 part by mass
・ 83 parts by mass of styrene
・ 17 parts by mass of n-butyl acrylate
・ Divinylbenzene (purity 55%) 0.1 parts by mass
・ Carbon black (BET specific surface area = 86m² / G) 5 parts by mass
・ 3 parts by mass of paraffin wax with a maximum endothermic peak of 70 ° C.
・ 5 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile)
A dispersion of the above mixture using an attritor (manufactured by Mitsui Miike Chemical Industries) for 3 hours was heated to 70 ° C. to prepare a polymerizable monomer composition.
[0184]
Next, the polymerizable monomer composition is charged into the aqueous dispersion medium and stirred for 15 minutes while maintaining the rotation speed of a high-speed stirrer at 12000 rpm at a liquid temperature of 70 ° C. in a nitrogen atmosphere. The composition was granulated. Subsequently, the suspension was changed to a propeller-type stirring blade and held at 70 ° C. for 10 hours while stirring at 50 rpm to obtain a suspension.
[0185]
Thereafter, the suspension was cooled and then dried by repeated filtration / water washing several times to obtain comparative particles (1). When filtration was performed, it was observed that the filtrate was colored dark brown.
[0186]
100 parts by mass of the above comparative particles (1) and fine hydrophobic silica powder (BET: 140 m²/ G) 0.9 part by mass was dry-mixed with a Henschel mixer to obtain a comparative toner (1).
[0187]
Comparative Example 2
Comparative particles (2) and comparative toner (2) were used in the same manner as in Comparative Example 1 except that 600 parts by mass of water containing 100 ppm of sodium dodecyl sulfate was used instead of the aqueous 1% polyvinyl alcohol solution as the aqueous continuous phase. Was prepared. When filtration was performed, it was observed that the filtrate was colored reddish brown.
[0188]
Comparative Example 3
Comparative particles (3) and comparative toner (3) were prepared in the same manner as in Example 1 except that the following chromium compound (i) was used in place of the compound (1). When the molecular weight of the particles was measured by GPC, the molecular weight of the main peak was 14,000, Mw was 9 million, and Mn was 12,000.
[0189]
Embedded image

[0190]
By NMR and X-ray fluorescence analysis, the amounts of the compounds (1) and (2) and fatty acids having 6 to 40 carbon atoms contained in the toners (1) to (10) and the comparative toners (1) to (3) were determined. It was measured. The results are shown in Table 1 together with the results of the circle-equivalent number average diameter, the ratio (number%) of particles of 2 μm or less to the total number of particles on the number basis, the average circularity, and the circularity standard deviation.
[0191]
[Table 1]

[0192]
  Examples 11-20 (however, Example 17 is a reference example) and Comparative Examples 4-6
  Evaluation was performed as follows using toners (1) to (10) and comparative toners (1) to (3) produced in Examples 1 to 10 and Comparative Examples 1 to 3.
[0193]
The developing device of the image forming apparatus shown in FIG. 1 was set so that the moving speed of the toner carrier surface was 2.0 times the moving speed of the electrostatic latent image carrier surface. Next, each of the toners (1) to (10) and the comparative toners (1) to (3) is filled in the developing machine, and the developing device is set in the image forming apparatus. RH) Under a printout speed of 12 sheets / minute (A4 size), 100 “Continuous” character patterns, 2 solid black images and 2 solid white images each, and then again “Continuous” character patterns Were continuously printed out and the obtained printout images were evaluated for the items described below. In addition, the amount of change in the charge amount of the toner on the surface of the toner carrying member after printing out 100 sheets and at the end of printing out was measured.
[0194]
The above evaluation results are summarized in Table 2.
[0195]
The toner carrier used here has a surface roughness Ra of 1.5, and the toner regulating blade is made of stainless steel.
[0196]
[Table 2]

[0197]
Example 21 and Comparative Example 7
Using the image forming apparatus of FIG. 2, the moving speed of the toner carrier surface is set to be 2.5 times the moving speed of the electrostatic latent image carrier surface, and then the toner (1) is placed in the developing unit. The comparative toner (3) was filled, and the developing device was set in the image forming apparatus. Under normal temperature and humidity (25 ° C, 60% RH) environment, 100 sheets of "Embarrass" character pattern, solid black image, solid white image at monochrome print mode, 12 sheets / minute (A4 size) printout speed Two copies of each, then 3000 consecutive “electric surprise” character patterns were printed out, and the obtained printout images were evaluated for the items described below. In addition, the amount of change in the charge amount of the toner on the surface of the toner carrying member after printing out 100 sheets and at the end of printing out was measured.
[0198]
5 and 6 is used as the heat fixing device, the surface temperature of the temperature detecting element 31d of the heating body 31 is 190 ° C., and the sponge pressure roller having a heating body 21-silicone rubber foam as a lower layer is used. The total pressure between 33 is 88.2 N (9 kgf), the nip between the pressure roller and the film is 8 mm, and the fixing film 32 has a conductive material dispersed in PTEF (high molecular weight type) on the contact surface with the transfer material. In addition, a heat-resistant polyimide film having a thickness of 60 μm having a low-resistance release layer was used.
[0199]
The above evaluation results are summarized in Table 3.
[0200]
The toner carrier used here has a surface roughness Ra of 1.4, and the toner regulating blade is made of stainless steel.
[0201]
[Table 3]

[0202]
  Examples 22 to 31 (however, Example 28 is a reference example) and Comparative Examples 8 to 10
  A 600 dpi laser beam printer (manufactured by Canon: LBP-860) was prepared as an electrophotographic apparatus. The process speed is modified to 60 mm / s.
[0203]
The cleaning rubber blade in this process cartridge was removed, and the charging method of the apparatus was direct charging performed by contacting a rubber roller, and the applied voltage was a direct current component (-1200 V).
[0204]
Next, the development part in the process cartridge was modified. Medium resistance rubber roller (diameter 16 mm, hardness ASKER C 45 degrees, resistance 10) made of silicone rubber dispersed with carbon black instead of stainless steel sleeve as toner supply body^Five(Ω · cm) was used as a toner carrier, and was in contact with the photoreceptor. The developing nip width at this time was set to about 3 mm. The rotation speed of the toner carrier is the same in the contact portion with the photoconductor, and is driven to be 140% of the rotation speed of the photoconductor.
[0205]
The photoconductor used here is an Al cylinder having a diameter of 30 mm and a diameter of 254 mm as a base, and layers having the following constitutions are sequentially laminated by dip coating to produce a photoconductor.
[0206]
(1) Conductive coating layer: Mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenolic resin. Film thickness 15 μm.
[0207]
(2) Undercoat layer: Mainly composed of modified nylon and copolymer nylon. Film thickness 0.6 μm.
[0208]
(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.
[0209]
(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 40 μm.
[0210]
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 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 about 20 g / cm. In addition, the applied voltage at the time of development was only a DC component (−450 V).
[0211]
The electrophotographic apparatus was remodeled and process conditions were set as follows in order to conform to the remodeling of these process cartridges.
[0212]
The modified device uses a roller charger (applying only direct current) to uniformly charge the 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 the toner image is transferred to a transfer material by a roller to which a voltage of +700 V is applied. The photosensitive member charging potential was -580V for the dark portion potential and -150V for the bright portion potential.
[0213]
Next, each of toners (1) to (10) and comparative toners (1) to (3) was filled in the developing unit, and the developing unit was set in the image forming apparatus. Under normal temperature and humidity (25 ° C, 60% RH) environment, the printout speed of 16 sheets / minute (A4 size), 100 sheets of “Amazing” character pattern, 2 solid black images and 2 solid white images each After that, 3000 “Electric surprise” character patterns were continuously printed out, and the obtained printout images were evaluated for the items described below. In addition, the amount of change in the charge amount of the toner on the surface of the toner carrying member after printing out 100 sheets and at the end of printing out was measured.
[0214]
The above evaluation results are summarized in Table 4.
[0215]
[Table 4]

[0216]
The description of the evaluation items described in the examples and comparative examples of the present invention and the evaluation criteria will be described.
[0217]
[Output image evaluation]
<1> Image density
The evaluation was based on the image density of the 101st solid black image. For the image density, a “Macbeth reflection densitometer” (manufactured by Macbeth) was used to measure a relative density with respect to a printout image of a white background portion having a document density of 0.00.
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
[0218]
<2> fog
The fog density (%) was calculated from the difference between the whiteness of the 103rd solid white image measured by “Reflectometer” (manufactured by Tokyo Denshoku) and the whiteness of the transfer paper, and the image fogging was evaluated.
A: Less than 1.5%
B: 1.5% or more and less than 3.0%
C: 3.0% or more and less than 5.0%
D: 5.0% or more
[0219]
<3> Missing
In the image of the last page in the printout test, the missing characters of the “surprise” character pattern shown in FIG. 4 were visually evaluated.
A: There is almost no void.
B: A slight void is observed.
C: Some voids are observed.
[0220]
【The invention's effect】
According to the present invention, it is possible to provide a dry toner and an image forming method capable of obtaining a high quality image with good charge rising and stable chargeability even when the printout speed is changed. .
[Brief description of the drawings]
FIG. 1 is an enlarged cross-sectional view of a main part of a developing device for one-component development used in an embodiment of the present invention.
FIG. 2 is a schematic diagram of a color image output apparatus using an intermediate transfer belt.
FIG. 3 is a schematic view of an image forming apparatus used in an embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating a state in which a character image is missing.
FIG. 5 is an exploded perspective view of a main part of the fixing device used in the embodiment of the present invention.
FIG. 6 is an enlarged cross-sectional view of a main part showing a film state when the fixing device used in the embodiment of the present invention is not driven.
FIG. 7 is a schematic diagram of a tomographic plane of toner according to the present invention.
[Explanation of symbols]
1 Photoconductor (electrostatic latent image carrier)
2 Charging roller
3 exposure
30 stays
31 Heating body
31a Heater board
31b Heating element
31c Surface protective layer
31d Temperature sensor
32 Fixing film
33 Pressure roller
34 Coil spring
35 Film edge regulating flange
36 Power connector
37 Power interruption member
38 Entrance guide
39 Exit guide (separation guide)
40 Intermediate transfer member
41 Yellow color developing device
42 Magenta color developing device
43 Cyan developing device
44 Black color developing device
51 Paper feed roller
52 Transfer residual toner cleaning device
53 Cleaning device
55 Fixing device
62 Primary transfer roller
63 Secondary transfer roller
64 Secondary transfer counter roller
65 Intermediate transfer belt support roller
66 Intermediate transfer belt support roller
100 Developer
102 Toner carrier
104 Toner
105 Transfer material
106 Transfer member
109 Photosensitive member (electrostatic image carrier)
110 Primary charging member
P transfer material

Claims (29)

A dry toner containing at least a binder resin, a colorant and a wax, the toner further containing a compound represented by the following general formula (1) and a fatty acid having 10 to 30 carbon atoms ;
The wax is a compound different from the fatty acid;
The content of the fatty acid is 30 to 3000 ppm and the content of the wax is 0.5 to 30% by mass with respect to the toner.
Circle-equivalent diameter based on the number of toner measured by the flow-type particle image measuring device - in circularity scattergram, the toner circle-equivalent number-average particle diameter D1 ([mu] m) is 2 to 10 [mu] m, and an average circularity A dry toner having a degree of 0.950 to 0.995 and a circularity standard deviation of less than 0.050.

  The dry toner according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.1 to 10% by mass based on the toner.   3. The dry toner according to claim 1, wherein the content of the fatty acid is 100 to 1000 ppm with respect to the toner. Dry toner according to any one of claims 1 to 3 endothermic peak in DSC of the wax, characterized in that the 40 to 130 ° C.. Dry toner according to the endothermic peak in DSC of the wax, any one of claims 1 to 3, characterized in that in the 50 to 100 ° C.. Dry toner according to any one of claims 1 to 5, wherein the colorant is a black colorant. Dry toner according to any one of claims 1 to 6, characterized in that contains at least carbon black as the coloring agent. Dry toner according to any one of claims 1 to 7, characterized in that said fatty acid is present on the toner surface. Dry toner according to any one of claims 1 to 8, characterized in that an acrylic resin - 50 to 100% by weight of the binder resin is a styrene. The dry toner according to any one of claims 1 to 8 , wherein 80 to 100% by mass of the binder resin is a styrene-acrylic resin. In the GPC chromatogram of the THF-soluble component of the binder resin, dry toner according to any one of claims 1 to 10, characterized in that a main peak is in the molecular weight region of 3,000 to 100,000. In the GPC chromatogram of the THF-soluble component of the binder resin, dry toner according to any one of claims 1 to 10, characterized in that a main peak is in the molecular weight region of 5,000 to 50,000. The circle equivalent number average particle diameter D1 (μm) of the toner is 2 to 10 μm, the average circularity of the toner is 0.970 to 0.995, and the circularity standard deviation is less than 0.040. dry toner according to any one of claims 1 to 12, wherein the. The observation of a tomographic plane of the toner particles using a transmission electron microscope (TEM), wherein the wax component is dispersed in a substantially spherical and / or spindle-shaped island shape in a binder resin. Item 14. The dry toner according to any one of Items 1 to 13 . A method for producing a toner by suspending in water and polymerizing a monomer composition having at least a monomer, a colorant, a wax component, a compound of the following general formula (1) and a fatty acid having 10 to 30 carbon atoms. Because
The wax is a compound different from the fatty acid;
The content of the fatty acid is 30 to 3000 ppm and the content of the wax is 0.5 to 30% by mass with respect to the toner.
In the toner-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring device, the circle equivalent number average particle diameter D1 (μm) of the toner is 2 to 10 μm, and the average circularity is Is a toner having a circularity standard deviation of less than 0.050.

At least a charging step in which a voltage is applied to the charging member from the outside to charge the electrostatic latent image carrier, a latent image forming step in which an electrostatic latent image is formed on the charged electrostatic latent image carrier, A development process for developing the charge image with dry toner to form a toner image on the electrostatic latent image carrier, a transfer process for transferring the toner image on the electrostatic latent image carrier to the transfer material, and a transfer material An image forming method comprising: a fixing step of heat-fixing a toner image,
The dry toner contains at least a binder resin, a colorant, and a wax, and further contains a compound of the following general formula (1) and a fatty acid having 10 to 30 carbon atoms .
The wax is a compound different from the fatty acid;
The content of the fatty acid is 30 to 3000 ppm and the content of the wax is 0.5 to 30% by mass with respect to the toner.
Circle-equivalent diameter based on the number of toner measured by the flow-type particle image measuring device - in circularity scattergram, the toner circle-equivalent number-average particle diameter D1 ([mu] m) is 2 to 10 [mu] m, and an average circularity An image forming method, wherein the degree is 0.950 to 0.995 and the circularity standard deviation is less than 0.050.

At least a charging step in which a voltage is applied to the charging member from the outside to charge the electrostatic latent image carrier, a latent image forming step in which an electrostatic latent image is formed on the charged electrostatic latent image carrier, A development step of developing the charge image with dry toner to form a toner image on the electrostatic latent image carrier, and a first transfer step of transferring the toner image on the electrostatic latent image carrier to the intermediate transfer member; An image forming method comprising: a second transfer step of transferring a toner image on the intermediate transfer member to a transfer material; and a fixing step of heating and fixing the toner image on the transfer material,
The dry toner contains at least a binder resin, a colorant, and a wax, and further contains a compound of the following general formula (1) and a fatty acid having 10 to 30 carbon atoms .
The wax is a compound different from the fatty acid;
The content of the fatty acid is 30 to 3000 ppm and the content of the wax is 0.5 to 30% by mass with respect to the toner.
Circle-equivalent diameter based on the number of toner measured by the flow-type particle image measuring device - in circularity scattergram, the toner circle-equivalent number-average particle diameter D1 ([mu] m) is 2 to 10 [mu] m, and an average circularity An image forming method, wherein the degree is 0.950 to 0.995 and the circularity standard deviation is less than 0.050.

During the transfer process in which the toner image on the electrostatic latent image carrier is electrostatically transferred onto a transfer material using a transfer device, the electrostatic latent image carrier and the transfer device are applied via the transfer material. The image forming method according to claim 16 , wherein the image forming method is in contact with each other. In the second transfer step in which the toner image on the intermediate transfer member is electrostatically transferred to the transfer material using the transfer device, the intermediate transfer member and the transfer device are in contact with each other via the transfer material. The image forming method according to claim 17 , wherein: Developing process, according to claim 16 or 19, characterized in that a step of performing development while contacting the toner is the electrostatic latent image and a thin layer coated on the toner carrying member on the latent electrostatic image bearing member The image forming method according to any one of the above. Electrostatic latent has a fixed gap there is image bearing member and the toner carrying member, an image forming method according to any one of claims 16 to 19, characterized in that the developer while applying an alternating electric field. In the developing step, the moving speed of the toner carrier surface in the developing region is 1.05 to 3.0 times the moving speed of the electrostatic latent image carrier surface, and the surface roughness Ra of the toner carrier. ([mu] m) is the image forming method according to any one of claims 16 to 21, characterized in that more than 1.5. The image forming method according to any one of claims 16 to 22, characterized in that arranging the toner carrier and opposite to the ferromagnetic metal blade with a small gap. The image forming method according to any one of claims 16 to 22, characterized in that contact blades made of the toner carrying member opposed to the elastic body. The charging step, the charging member is brought into contact with the electrostatic latent image bearing member, a voltage is applied to from the charging member outside any of claims 16 to 24, characterized in that charging the latent electrostatic image bearing member An image forming method according to claim 1. Heating fixing process, there is no supply of the liquid for preventing the offset, or by not having heat fixing device fuser cleaner, any one of claims 16 to 25, characterized in that for heating and fixing the toner image on the transfer material The image forming method described in 1. The heat fixing step heat-fixes the toner image on the transfer material by a fixedly supported heating body and a pressure member that is in pressure-contact with the heating body and is in close contact with the heating body through a film. the image forming method according to any one of claims 16 to 26, characterized. After the transfer, the untransferred residual toner on the electrostatic latent image carrier is cleaned and collected, and the collected toner is supplied to the developing means and held in the developing means again. the image forming method according to any one of claims 16 to 27 characterized by having a toner reuse mechanism for developing the electrostatic latent image. The image forming method according to claim 16 or 17 which comprises using a toner according to any one of claims 2 to 14.

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