JP2004252303A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method and a developer which can excellently suppress deterioration of a toner even in an environment of high temperature and low humidity and in an environment of low temperature and low humidity and can also excellently suppress contamination of members. <P>SOLUTION: The nonmagnetic single component toner for an image forming method has: toner particles consisting at least of a binder resin, a colorant and a release agent; and an external additive. One or more kinds of fine silica powders treated with at least silicone oil are contained as the external additive. The average circularity of the toner in a number-based equivalent circular diameter-circularity scattergram measured with a flow type particle image measuring device ranges from 0.95 to 1.00, the weight average particle diameter A of the toner from 3 to 9 μm, the BET specific surface area B is from 1.2 to 3.3 (m<SP>2</SP>/g), and the product A×B is from 5 to 25. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２８】
〔式中、ＲはＣ１〜３のアルキル基を示し、Ｒ’はアルキル、ハロゲン変性アルキル、フェニル、変性フェニルの如きシリコーンオイル変性基を示し、Ｒ”はＣ１〜３のアルキル基またはアルコオキシ基を示す。〕
例えば、ジメチルシリコーンオイル、アルキル変性シリコーンオイル、α−メチルスチレン変性シリコーンオイル、クロルフェニルシリコーンオイル、フッ素変性シリコーンオイルが挙げられる。上記シリコーンオイルは、２５℃における粘度が５０〜１００ｍｍ^２／ｓのものが好ましく用いられる。
【００２９】
オイルによる処理量としては微粉末母体１００質量部に対し３〜３５質量部であると本発明の画像形成装置における現像特性が良好である。
【００３０】
オイル処理量が３質量部未満の場合、部材への汚染を防止する効果が発現しにくい。
【００３１】
オイル処理量が３５質量部を超える場合、処理された外添剤が凝集しやすくなり、トナーの帯電性、現像性を不均一なものとしてしまう。
【００３２】
本発明の場合、５〜２５質量部であると本発明の画像形成装置における現像特性がさらに向上する。
【００３３】
本発明に用いられる外添剤は従来公知のものを用いることが出来るが、現像性、流動性、保存性向上のためシリカ、アルミナ、チタニアあるいはそれらの副酸化物から選ばれることが好ましい。
【００３４】
例えばシリカは、硅素ハロゲン化物やアルコキシドの蒸気相酸化により生成されたいわゆる乾式法またはヒュームドシリカと称される乾式法シリカ、およびアルコキシド、水ガラスから製造される湿式シリカの両方が使用可能であるが、表面および微粉体内部にあるシラノール基が少なく、また、製造残査の少ない乾式シリカの方が好ましい。
【００３５】
シリカ微粉末を例にした場合、ケイ素ハロゲン化物を気相酸化することによりシリカ微粉末を生成し、得られたシリカ微粉末を疎水化処理することにより非球状のシリカ微粉末を製造する。特に気相酸化の際、シリカの一次粒子が合一する程度の高温で焼成しても良い。
【００３６】
また、本発明において外添剤は疎水性を高め、粒径や形状制御の操作性を向上させる目的でシランカップリング処理やアルミナ被膜を形成する表面処理をしても良い。
【００３７】
具体的にはシランカップリング剤としてはヘキサメチルジシラザンまたは下記式（１）に示されるものが挙げられる。
【００３８】
ＲｍＳｉＹｎ …（１）
Ｒ：アルコキシ基または塩素原子
ｍ：１〜３の整数
Ｙ：アルキル基またはビニル基、グルシドキシ基またはメタクリル基を含む炭化水素基
ｎ：１〜３の整数
上記（１）で示される化合物としては、例えば代表的にはジメチルジクロルシラン、トリメチルクロルシラン、アリルジメチルクロルシラン、アリルフェニルジクロルシラン、ベンジルジメチルクロルシラン、ビニルトリエトキシシラン、γ−メタクリルオキシプロピルトリメトキシシラン、イソブチルトリメトキシシラン、ｎ−ブチルトリメトキシシラン、ビニルトリアセトキシシラン、ジビニルクロルシラン、ジメチルビニルクロルシラン等を挙げることが出来る。
【００３９】
シランカップリング剤処理の方法としては微粉体を撹拌によってクラウド状としたものに気化したシランカップリング剤を反応させる乾式法または微粉体を溶媒中に分散させシランカップリング剤を滴下反応させる湿式法のいずれでも処理することが出来る。
【００４０】
アルミナ被膜を形成させる方法としては、水溶液中または溶媒中で塩化アルミニウム、硝酸アルミニウム、硫酸アルミニウム等を添加し、微粒子を浸漬、乾燥する方法、あるいは含水アルミナ、含水アルミナ−シリカ、含水アルミナ−チタニア、含水アルミナ−チタニア−シリカ、または含水アルミナ−チタニア−シリカ−酸化亜鉛を添加し、その水溶液に微粒子を浸漬、乾燥する方法によって実施することが出来る。
【００４１】
本発明に用いられる外添剤の他に、帯電量の調整や、流動性の補助等のためさらに微粉末を添加しても良い。
【００４２】
例えば流動性付与剤としては、金属酸化物（酸化ケイ素、酸化アルミニウム、酸化チタンなど）カーボンブラック、シリカなどが挙げられ、それぞれ、疎水化処理を行ったものが、より好ましい。研磨剤としては、金属酸化物（チタン酸ストロンチウム、酸化セリウム、酸化アルミニウム、酸化マグネシウム、酸化クロムなど）・窒化物（窒化ケイ素など）・炭化物（炭化ケイ素など）・金属塩（硫酸カルシウム、硫酸バリウム、炭酸カルシウムなど）が挙げられる。荷電制御性粒子としては、金属酸化物（酸化錫、酸化チタン、酸化亜鉛、酸化ケイ素、酸化アルミニウムなど）・カーボンブラックなどが上げられる。
【００４３】
また、外添剤をトナー粒子１００質量部に対して０．８質量部以上含有することが好ましい。これは帯電ローラによる帯電工程や中間転写体を用いる転写工程のような接触部材間をトナーが通過する回数の多い画像形成装置において、トナーが部材間のニップでこすられることによるトナー劣化を防止するのに必要な量である。さらには、トナーの凝集度が５乃至３０％であることが好ましい。これにより帯電ローラによる帯電工程や中間転写体を用いる転写工程のような接触部材間をトナーが通過する回数の多い画像形成装置において、トナーが部材間のニップでこすられることによるトナー劣化を防止し、転写性を維持することが可能となる。
【００４４】
さらに、トナーのフロー式粒子像分析装置によって測定される円相当径による粒度分布において、平均円形度が０．９５乃至１．００であることが好ましい。ここにフロー式粒子像測定装置とは、粒子撮像の画像解析を統計的に行う装置であり、平均円形度は該装置を用い次式によって求められた円形度の相加平均によって算出される。
【００４５】
【数１】

【００４６】
上式において、粒子投影像の周囲長とは、二値化された粒子像のエッジ点を結んで得られる輪郭線の長さであり、相当円の周囲長とは、二値化された粒子像と同じ面積を有する円の外周の長さである。
【００４７】
円相当径とは、測定された粒子の２次元画像の面積と同面積を有する円の直径である。
【００４８】
フロー式粒子像測定装置としてＦＰＩＡ−１０００（東亜医用電子社製）をもちいる。
【００４９】
測定方法としては、イオン交換水に界面活性剤（好ましくは和光純薬製コンタミノン）を０．１〜０．５質量％加えて調製した溶液１０ｍｌ（２０℃）に、測定試料を０．０２ｇ加えて均一に分散させて試料分散液を調製した。
【００５０】
分散させる手段としては、エスエムテー社製の超音波分散機ＵＭ−５０（振動子は５φのチタン合金チップ）を用い、分散時間は５分とし、その際、分散媒の温度が４０℃以上にならないように冷却した。
【００５１】
測定は０．６０〜４００μｍの範囲を２２６チャンネルに分割し、実際の測定では円相当径が０．６０μｍ以上１５９．２１μｍ未満の範囲で粒子の測定を行う。
【００５２】
平均円形度が０．９５乃至１．００であると、一次転写および二次転写での転写トナー残が少なくクリーニング部材をすり抜けるトナーおよび外添剤も少なくなり部材の汚染抑制効果が高い。
【００５３】
一方、平均円形度が０．９５未満の場合、一次転写および二次転写での転写トナー残が多くクリーニング部材をすり抜けるトナーおよび外添剤も多くなり部材の汚染が進行する。
【００５４】
本発明において、上述した特定の平均円形度を有するトナーを製造する方法としては例えば、粉砕法により製造されたトナー粒子を機械的または熱的に球形化処理してトナーを製造する方法、および重合法により直接トナーを製造する方法が挙げられる。
【００５５】
さらに、該トナーの重量平均粒径Ａが３乃至９μｍであって、かつトナーのＢＥＴ比表面積Ｂが１．２乃至３．３（ｍ^２／ｇ）であり、その積Ａ×Ｂが５乃至２５であると、トナー劣化抑制の相乗効果が得られる。
【００５６】
ここで、トナーのＢＥＴ比表面性は母粒子の粒径と形状に影響され、さらには母粒子に添加する外添剤のＢＥＴ比表面積および添加量に影響される。特に外添剤の添加量の影響は大きく、多数枚の耐久に耐えうるトナーとしては外添剤の添加量を調整し、適正なＢＥＴ比表面積にする事が求められる。
【００５７】
トナーのＢＥＴ比表面積Ｂが１．２（ｍ^２／ｇ）未満であると外添剤が少なすぎ、ガサツキ等の画像欠陥が生じやすい。
【００５８】
一方、トナーのＢＥＴ比表面積Ｂが３．３（ｍ^２／ｇ）を超えると外添剤が多すぎたり、トナーの形状の凹凸が多い場合であり、耐久前後でのＢＥＴ比表面積の変化率が大きくなり画像欠陥を生じやすい。
【００５９】
本発明の場合、トナーのＢＥＴ比表面積Ｂが１．５乃至３．０（ｍ２／ｇ）であると、より好ましい。
【００６０】
また、該トナーの重量平均粒径ＡとトナーのＢＥＴ比表面積Ｂの積Ａ×Ｂが５未満であると外添剤が少なすぎ、ガサツキ等の画像欠陥が生じやすい。２５を超えると外添剤が多すぎたり、トナーの形状の凹凸が多い場合であり、耐久前後でのＢＥＴ比表面積の変化率が大きくなり画像欠陥を生じやすい。
【００６１】
本発明においては、該トナーの重量平均粒径Ａ、トナーのＢＥＴ比表面積Ｂの積Ａ×Ｂが１０乃至２０であると、トナー劣化抑制のさらなる相乗効果が得られて好ましい。
【００６２】
本発明におけるＢＥＴ比表面積の測定は、脱ガス装置バキュプレップ０６１（マイクロメソティック社製）およびＢＥＴ測定装置ジェミニ２３７５（マイクロメソティック社製）を用いて測定を行う。サンプル調製手順であるが、まず、空のサンプルセルの重量を測定した後、測定試料を１〜１．０１ｇの間に入るように充填し、脱ガス装置に、試料が充填されたサンプルセルをセットし、室温で３時間脱ガスを行う。脱ガス終了後、サンプルセル全体の質量を測定し、空サンプルセルとの差から試料の正確な質量を算出する。ＢＥＴ比表面積の測定手順を説明する。まず、ＢＥＴ測定装置のバランスポートおよび分析ポートに空のサンプルセルをセットする。次に、所定の位置に液体窒素の入ったデュワー瓶をセットし、飽和蒸気圧（Ｐ０）測定コマンドにより、Ｐ０を測定する。Ｐ０測定終了後、分析ポートに調製されたサンプルセルをセットし、サンプル質量およびＰ０を入力後、ＢＥＴ測定コマンドにより測定を開始する。後は自動でＢＥＴ比表面積が算出される。
【００６３】
本発明のトナーに用いられる低軟化点物質としては、例えば、パラフィン系ワックス、ポリオレフィン系ワックス、これらの変性物（例えば、酸化物やグラフト処理物）、高級脂肪酸およびその金属塩、アミドワックス、ケトンワックス、及びエステル系ワックスなどが挙げられるが、カラートナーに使用する場合は結晶性が高いとＯＨＰの透過性を妨げることから、アミドワックス、エステルワックスが好ましい。
【００６４】
低軟化点物質は０．５乃至３０質量％配合するのが良い。
【００６５】
低軟化点物質の配合量が下限より少ないとオフセット防止効果が低下しやすく、上限を超える場合、耐ブロッキング効果が低下し耐オフセット効果にも悪影響を与えやすく、ドラム融着やスリーブ融着を起こしやすく、特に重合トナー製法の場合には粒度分布の広いトナーが生成する傾向にある。
【００６６】
また、本発明に用いられる低軟化点物質はＧＰＣ（ゲルパーミエーションクロマトグラフィー）により測定される分子量分布において、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．０〜１．５であることが好ましい。
【００６７】
これは、低軟化点物質のＭｗ／Ｍｎの値が１．０に近いほど分子量分布がシャープであることを表す。具体的には定着時に熱がかかったときに良好な溶融特性を示し、トナー表面への染み出しが早く、良好な定着特性を示す。このことにより、上述してきたトナー表面の物質のコントロールと合わせることで相乗効果が得られる。
【００６８】
低軟化点物質のＧＰＣ（ゲルパーミエーションクロマトグラフィー）により測定される分子量分布において、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．５より大きいと低軟化点物質のトナー表面への染み出しが遅くなり、定着特性が悪くなる。
【００６９】
低軟化点物質の分子量はＧＰＣにより次の条件で測定される。
【００７０】
（ＧＰＣ測定条件）
装置：ＧＰＣ−１５０Ｃ（ウォーターズ社）
カラム：ＧＭＨ−ＨＴ３０ｃｍ２連（東ソー社製）
温度：１３５℃
溶媒：ｏ−ジクロロベンゼン（０．１％アイオノール添加）
流速：１．０ｍｌ／ｍｉｎ
試料：０．１５％の試料を０．４ｍｌ注入
以上の条件で測定し、試料の分子量算出に当たっては単分散ポリスチレン標準試料により作成した分子量校正曲線を使用する。更に、Ｍａｒｋ−Ｈｏｕｗｉｎｋ粘度式から導き出される換算式でポリエチレン換算することによって算出される。
【００７１】
本発明のトナーに使用される結着樹脂としては、下記の結着樹脂の使用が可能である。
【００７２】
例えば、ポリスチレン、ポリ−ｐ−クロルスチレン、ポリビニルトルエンの如きスチレンおよびその置換体の単重合体；スチレン−ｐ−クロルスチレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体、スチレン−α−クロルメタクリル酸メチル共重合体、スチレン−アクリロニトリル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−アクリロニトリル−インデン共重合体の如きスチレン系共重合体；ポリ塩化ビニル；フェノール樹脂；天然変性フェノール樹脂；天然変性マレイン酸樹脂；アクリル樹脂；メタクリル樹脂；ポリ酢酸ビニル；シリコーン樹脂；ポリエステル樹脂；ポリウレタン；ポリアミド樹脂；フラン樹脂；エポキシ樹脂；キシレン樹脂；ポリビニルブチラール；テルペン樹脂；クマロンインデン樹脂；石油系樹脂が使用できる。好ましい結着物質としては、スチレン系共重合体もしくはポリエステル樹脂があげられる。
【００７３】
スチレン系共重合体のスチレンモノマーに対するコモノマーとしては、例えば、アクリル酸、アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸ドデシル、アクリル酸オクチル、アクリル酸−２−エチルヘキシル、アクリル酸フェニル、メタクリル酸、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸オクチル、アクリロニトリル、メタクリロニトリル、アクリルアミドのような二重結合を有するモノカルボン酸もしくはその置換体；例えば、マレイン酸、マレイン酸ブチル、マレイン酸メチル、マレイン酸ジメチルのような二重結合を有するジカルボン酸およびその置換体；例えば、塩化ビニル、酢酸ビニル、安息香酸ビニルのようなビニルエステル類；例えば、エチレン、プロピレン、ブチレンのようなエチレン系オレフィン類；例えば、ビニルメチルケトン、ビニルヘキシルケトンのようなビニルケトン類；例えば、ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテルのようなビニルエーテル類；の如きビニル系単量体が単独もしくは２つ以上用いられる。
【００７４】
スチレン系重合体またはスチレン系共重合体は架橋されていても良く、さらに架橋されている樹脂と架橋されていない樹脂との混合樹脂でも良い。
【００７５】
結着樹脂の架橋剤としては、主として２個以上の重合可能な二重結合を有する化合物を用いてもよい。例えば、ジビニルベンゼン、ジビニルナフタレンのような芳香族ジビニル化合物；例えば、エチレングリコールジアクリレート、エチレングリコールジメタクリレート、１，３−ブタンジオールジメタクリレートのような二重結合を２個有するカルボン酸エステル；例えば、ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホンの如きジビニル化合物；および３個以上のビニル基を有する化合物；が単独もしくは混合物として用いられる。
【００７６】
架橋剤の添加量としては、重合性単量体１００質量部に対して０．００１〜１０質量部が好ましい。
【００７７】
本発明のトナーは、荷電制御剤を含有しても良い。
【００７８】
トナーを負荷電性に制御するものとして下記物質がある。
【００７９】
例えば、有機金属化合物、キレート化合物が有効であり、モノアゾ金属化合物、アセチルアセトン金属化合物、芳香族ハイドロキシカルボン酸、芳香族ダイカルボン酸系の金属化合物がある。他には、芳香族ハイドロキシカルボン酸、芳香族モノ及びポリカルボン酸及びその金属塩、無水物、エステル類、ビスフェノール等のフェノール誘導体類などがある。また、尿素誘導体、含金属サリチル酸系化合物、含金属ナフトエ酸系化合物、ホウ素化合物、４級アンモニウム塩、カリックスアレーン、ケイ素化合物、スチレン−アクリル酸共重合体、スチレン−メタクリル酸共重合体、スチレン−アクリル−スルホン酸共重合体、ノンメタルカルボン酸系化合物等が挙げられる。また、上記荷電制御化合物をペンダントした樹脂をトナー中に内添させても良い。
【００８０】
トナーを正荷電性に制御するものとして下記物質がある。
【００８１】
例えば、ニグロシン及び脂肪酸金属塩等による変性物、グアニジン化合物、イミダゾール化合物、トリブチルベンジルアンモニウム−１−ヒドロキシ−４−ナフトスルフォン酸塩、テトラブチルアンモニウムテトラフルオロボレートなどの４級アンモニウム塩、及びこれらの類似体であるホスホニウム塩等のオニウム塩及びこれらのレーキ顔料、トリフェニルメタン染料及びこれらのレーキ顔料（レーキ化剤としては、燐タングステン酸、燐モリブデン酸、燐タングステンモリブデン酸、タンニン酸、ラウリン酸、没食子酸、フェリシアン化物、フェロシアン化物など）、高級脂肪酸の金属塩；ジブチルスズオキサイド、ジオクチルスズオキサイド、ジシクロヘキシルスズオキサイドなどのジオルガノスズオキサイド；ジブチルスズボレート、ジオクチルスズボレート、ジシクロヘキシルスズボレートなどのジオルガノスズボレート類；これらを単独で或は２種類以上組合わせて用いることができる。これらの中でも、ニグロシン系、４級アンモニウム塩の如き荷電制御剤が特に好ましく用いられる。また、上記荷電制御化合物をペンダントした樹脂をトナー中に内添させても良い。
【００８２】
これらの荷電制御剤は、樹脂成分１００質量部に対して、０．０１〜２０質量部（より好ましくは０．５〜１０質量部）使用するのが良い。
【００８３】
本発明に用いられる着色剤は、黒色着色剤としてカーボンブラックのほかに以下に示すイエロー／マゼンタ／シアン着色剤を用い黒色に調色されたものが利用される。
【００８４】
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．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ３、７、１０、１２、１３、１４、１５、１７、２３、２４、６０、６２、７４、７５、８３、９３、９４、９５、９９、１００、１０１、１０４、１０８、１０９、１１０、１１１、１１７、１２３、１２８、１２９、１３８、１３９、１４７、１４８、１５０、１６６、１６８、１６９、１７７、１７９、１８０、１８１、１８３、１８５、１９１、１９２、１７０、１９９等が好適に用いられる。また、染料としてＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｙｅｌｌｏｗ３３、５６、７９、８２、９３、１１２、１６２、１６３、Ｃ．Ｉ．Ｄｉｓｐｅｒｓｅ Ｙｅｌｌｏｗ４２、６４、２０１、２１１等があげられる。また、必要に応じてイエロー顔料、染料を単独で使用しても、もしくは顔料と染料と併用しても良い。
【００８５】
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，アントラキノン，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．Ｐｉｇｍｅｎｔ Ｒｅｄ２、３、５、６、７、２３、４８：２、４８：３、４８：４、５７：１、８１：１、１２２、１４６、１６６、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４やＣ．Ｉ．Ｐｉｇｍｅｎｔ Ｖｉｏｌｅｔ１９等が特に好ましい。また、必要に応じてマゼンタ顔料、染料を単独で使用しても、もしくは顔料と染料と併用しても良い。
【００８６】
本発明に用いられる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，アントラキノン化合物，塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｂｌｕｅ１、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。また、必要に応じてシアン顔料、染料を単独で使用しても、もしくは顔料と染料と併用しても良い。
【００８７】
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。本発明の着色剤は、色相角，彩度，明度，耐候性，ＯＨＰ透明性，トナー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１００質量部に対し１〜２０質量部添加して用いられる。
【００８８】
次に本発明に用いられるトナーを製造するための方法について説明する。本発明に用いられるトナーは、粉砕トナー製法及び重合トナー製法を用いて製造することが可能である。
【００８９】
本発明において、粉砕トナーの製造方法は結着樹脂、低軟化点物質、着色剤としての顔料、染料又は磁性体、必要に応じて荷電制御剤、その他の添加剤を、ヘンシェルミキサー、ボールミルの如き混合機により充分混合し；得られた混合物を加熱ロール、ニーダー、エクストルーダーの如き熱混練機を用いて溶融混練し、樹脂成分を互いに相溶せしめた中に低軟化点物質、顔料、染料、磁性体を分散又は溶解せしめ；得られた混練物を冷却固化後粉砕及び分級を行ってトナーを得る。
【００９０】
さらに必要に応じてトナーと所望の添加剤をヘンシェルミキサーの如き混合機により充分混合し、本発明に用いられるトナーを得ることができる。
【００９１】
本発明において、重合トナーの製造方法は、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溶融混合物を空気中に霧化し球状トナーを得る方法や、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懸濁重合法を用いて直接トナーを生成する方法や、単量体には可溶で得られる重合体が不溶な水系有機溶剤を用い直接トナーを生成する分散重合法又は水溶性極性重合開始剤存在下で直接重合しトナーを生成するソープフリー重合法に代表される乳化重合法や、予め一次極性乳化重合粒子を作った後、反対電荷を有する極性粒子を加え会合させるヘテロ凝集法等を用いトナーを製造することが可能である。
【００９２】
しかしながら、分散重合法においては、得られるトナーは極めてシャープな粒度分布を示すが、使用する材料の選択が狭いことや有機溶剤の利用が廃溶剤の処理や溶剤の引火性に関する観点から製造装置が複雑で煩雑化しやすい。ソープフリー重合に代表される乳化重合法は、トナーの粒度分布が比較的揃うため有効であるが、使用した乳化剤や開始剤末端がトナー粒子表面に存在した時に環境特性を悪化させやすい。
【００９３】
従って、本発明においては比較的容易に粒度分布がシャープな微粒子トナーが得られる常圧下での、または、加圧下での懸濁重合法が特に好ましい。一旦得られた重合粒子に更に単量体を吸着せしめた後、重合開始剤を用い重合せしめる所謂シード重合方法も本発明に好適に利用することができる。
【００９４】
本発明のトナー製造方法に直接重合方法を用いる場合においては、以下の如き製造方法によって具体的にトナーを製造することが可能である。単量体中に低軟化点物質，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系を、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・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。また、重合反応後半に昇温しても良く、更に、トナー定着時の臭いの原因等となる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、通常単量体系１００質量部に対して水３００〜３０００質量部を分散媒として使用するのが好ましい。
【００９５】
本発明に用いられるより好ましいトナーは、透過電子顕微鏡（ＴＥＭ）を用いたトナーの断層面測定法で低軟化点物質が、外殻樹脂層で内包化された直接重合法を用いて製造されたものである。定着性の観点から多量の低軟化点物質をトナーに含有せしめる必要性から、必然的な低軟化点物質を外殻樹脂中に内包化せしめる必要がある。内包化せしめない場合のトナーは、粉砕工程において特殊な凍結粉砕を利用しないと十分な微粉砕化ができず結果的に粒度分布の広いものしか得られず、装置へのトナー融着も発生し甚だ好ましくない。また冷凍粉砕においては、装置への結露防止策のため装置が煩雑化したり、仮にトナーが吸湿した場合においてはトナーの作業性低下を招き、更に乾燥工程を追加することも必要となり問題となる。該低軟化点物質を内包化せしめる具体的な方法としては、水系媒体中での材料の極性を主要単量体より低軟化点物質の方を小さく設定し、更に少量の極性の大きな樹脂又は単量体を添加せしめることで低軟化点物質を外殻樹脂で被覆した所謂コア−シェル構造を有するトナーを得ることができる。トナー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本発明のトナーを得ることができる。
【００９６】
本発明においてトナーの断層面を測定する具体的な方法としては、常温硬化性のエポキシ樹脂中にトナーを十分分散させた後温度４０℃の雰囲気中で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透過電子顕微鏡（ＴＥＭ）を用いトナーの断層形態を測定した。本発明においては、用いる該低軟化点物質と外殻を構成する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付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。
【００９７】
重合法によりトナーを製造する場合に用いられるラジカル重合が可能なビニル系重合性単量体としては、単官能性重合性単量体あるいは多官能性重合性単量体を使用することができる。
【００９８】
単官能性重合性単量体としては、スチレン、α−メチルスチレン、β−メチルスチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、２，４−ジメチルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン、ｐ−ｎ−ドデシルスチレン、ｐ−メトキシスチレン、ｐ−フェニルスチレンなどのスチレン系重合性単量体；メチルアクリレート、エチルアクリレート、ｎ−プロピルアクリレート、ｉｓｏ−プロピルアクリレート、ｎ−ブチルアクリレート、ｉｓｏ−ブチルアクリレート、ｔｅｒｔ−ブチルアクリレート、ｎ−アミルアクリレート、ｎ−ヘキシルアクリレート、２−エチルヘキシルアクリレート、ｎ−オクチルアクリレート、ｎ−ノニルアクリレート、シクロヘキシルアクリレート、ベンジルアクリレート、ジメチルフォスフェートエチルアクリレート、ジブチルフォスフェートエチルアクリレート、２−ベンゾイルオキシエチルアクリレートなどのアクリル系重合性単量体；メチルメタクリレート、エチルメタクリレート、ｎ−プロピルメタクリレート、ｉｓｏ−プロピルメタクリレート、ｎ−ブチルメタクリレート、ｉｓｏ−ブチルメタクリレート、ｔｅｒｔ−ブチルメタクリレート、ｎ−アミルメタクリレート、ｎ−ヘキシルメタクリレート、２−エチルヘキシルメタクリレート、ｎ−オクチルメタクリレート、ｎ−ノニルメタクリレート、ジエチルフォスフェートエチルメタクリレート、ジブチルフォスフェートエチルメタクリレートなどのメタクリル系重合性単量体；メチレン脂肪族モノカルボン酸エステル類；酢酸ビニル、プロピオン酸ビニル、ベンゾエ酸ビニル、酪酸ビニル、安息香酸ビニル、ギ酸ビニルなどのビニルエステル類；ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテル等のビニルエーテル類；ビニルメチルケトン、ビニルヘキシルケトン、ビニルイソプロピルケトン等のビニルケトン類などのビニル系重合性単量体等が挙げられる。
【００９９】
多官能性重合性単量体としては、ジエチレングリコールジアクリレート、トリエチレングリコールジアクリレート、テトラエチレングリコールジアクリレート、ポリエチレングリコールジアクリレート、１，６−ヘキサンジオールジアクリレート、ネオペンチルグリコールジアクリレート、トリプロピレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、２，２’−ビス［４−（アクリロキシ・ジエトキシ）フェニル］プロパン、トリメチロールプロパントリアクリレート、テトラメチロールメタンテトラアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレート、ポリエチレングリコールジメタクリレート、１，３−ブチレングリコールジメタクリレート、１，６−ヘキサンジオールジメタクリレート、ネオペンチルグリコールジメタクリレート、ポリプロピレングリコールジメタクリレート、２，２’−ビス［４−（メタクリロキシ・ジエトキシ）フェニル］プロパン、２，２’−ビス［４−（メタクリロキシ・ポリエトキシ）フェニル］プロパン、トリメチロールプロパントリメタクリレート、テトラメチロールメタンテトラメタクリレート、ジビニルベンゼン、ジビニルナフタリン、ジビニルエーテル等を挙げることができる。
【０１００】
前記単官能性重合性単量体を単独あるいは２種以上組み合わせて、また、単官能性重合性単量体と多官能性重合性単量体を組み合わせて使用することができる。また、前記多官能性重合性単量体を架橋剤として使用することも可能である。
【０１０１】
本発明において、トナーにコア−シェル構造を形成せしめるためには、極性樹脂を併用することが好ましい。本発明に使用できる極性重合体及び極性共重合体の如き極性樹脂を以下に例示する。
【０１０２】
極性樹脂としては、メタクリル酸ジメチルアミノエチル、メタクリル酸ジエチルアミノエチルの如き含窒素単量体の重合体もしくは含窒素単量体とスチレン−不飽和カルボン酸エステルとの共重合体；アクリロニトリルの如きニトリル系単量体；塩化ビニルの如き含ハロゲン系単量体；アクリル酸、メタクリル酸の如き不飽和カルボン酸；不飽和二塩基酸；不飽和二塩基酸無水物；ニトロ系単量体の重合体もしくはそれとスチレン系単量体との共重合体；ポリエステル；エポキシ樹脂；が挙げられる。より好ましいものとして、スチレンと（メタ）アクリル酸の共重合体、マレイン酸共重合体、飽和または不飽和のポリエステル樹脂、エポキシ樹脂が挙げられる。
【０１０３】
重合開始剤としては、例えば、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリル、アゾビスイソブチロニトリル等の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、ｔ−ブチルヒドロペルオキシド、ジ−ｔ−ブチルペルオキシド、ジクシルペルオキシド、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、２，２−ビス（４，４−ｔ−ブチルペルオキシシクロヘキシル）プロパン、トリス−（ｔ−ブチルペルオキシ）トリアジンなどの過酸化物系開始剤や、過酸化物を側鎖に有する高分子開始剤、過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩、過酸化水素などが使用される。
【０１０４】
重合開始剤は重合性単量体１００質量部当り０．５〜２０質量部の添加量が好ましく、単独で又は、併用しても良い。
【０１０５】
また、本発明では分子量をコントロールするために、公知の架橋剤、連鎖移動剤を添加しても良く、好ましい添加量としては０．００１〜１５質量部である。
【０１０６】
本発明において、乳化重合，分散重合，懸濁重合，シード重合，ヘテロ凝集法を用いる重合法等によって、重合法トナーを製造する際に用いられる分散媒には、いずれか適当な安定剤を使用する。例えば、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、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、ポリアクリルアミド、ポリエチレンオキシド、ポリ（ハイドロオキシステアリン酸−ｇ−メタクリル酸メチル−ｅｕ−メタクリル酸）共重合体やノニオン系或はイオン系界面活性剤などが使用される。
【０１０７】
また、乳化重合法及びヘテロ凝集法を用いる場合には、アニオン系界面活性剤、カチオン系界面活性剤、両性イオン界面活性剤及びノニオン系界面活性剤が使用される。これらの安定剤は重合性単量体１００質量部に対して０．２〜３０質量部を使用することが好ましい。
【０１０８】
これら安定化剤の中で、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、分散媒中にて該無機化合物を生成させても良い。
【０１０９】
また、これら安定化剤の微細な分散の為に、０．００１〜０．１質量部の界面活性剤を使用してもよい。これは上記分散安定化剤の所期の作用を促進する為のものであり、その具体例としては、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。
【０１１０】
次に本発明に好ましい画像形成装置を示す。
【０１１１】
（１）画像形成装置例
図１は非磁性一成分接触現像方式の電子写真プロセスを利用した現像器の概略図である。本実施例では以下の（ａ）〜（ｈ）の部分を改造した装置を使用した。
（ａ）プロセススピードを、８５ ｍｍ／ｓに変更。
（ｂ）装置の帯電方式をゴムローラに当接して行う直接帯電とし、印加電圧を直流成分（−４５０Ｖ）とした。（直径９ｍｍ、ＡＳＫＥＲ−Ｃ硬度６０度）
（ｃ）トナー担持体を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１２ｍｍ、ＡＳＫＥＲ−Ｃ硬度４５度）に変更し感光体に当接した。
（ｄ）該トナー担持体の回転は感光体との接触部分において同方向であり、周速は１３５ ｍｍ／ｓとなるように駆動した。
（ｅ）感光体は以下のものに変更した。
【０１１２】
ここで用いる感光体としてはＡｌシリンダーを基体としたもので、これに以下に示すような構成の層を順次浸漬塗布により積層して感光体を作成した。（直径２５ｍｍ）
（１） 導電性被覆層：酸化錫およ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１５ μｍ。
（２） 下引き層：変性ナイロン、および共重合ナイロンを主体とする。膜厚０．６μｍ。
（３） 電荷発生層：長波長域に吸収を持つチタニルフタロシアニン顔料をブチラール樹脂に分散したものを主体とする。膜厚０．６μｍ。
（４） 電荷輸送層：正孔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２０ μｍ。
【０１１３】
感光体の周速は８５ ｍｍ／ｓに設定した。
（ｆ）トナー担持体にトナーを塗布する手段として、現像機内に発泡ウレタンゴムからなる該弾性ローラ（セル数は１インチ当たり５０乃至１００個， ＡＳＫＥＲ−Ｆ硬度が５５度， 直径１６ ｍｍ）を設けて、該トナー担持体に当接させた。該弾性ローラの回転は該トナー担持体に対して接触部分において逆方向であり、周速は９５ ｍｍ／ｓに設定した。
（ｇ）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用いた。
（ｈ）現像時の印加電圧をＤＣ成分（−２５０乃至−３００ Ｖ）のみとした。
【０１１４】
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って静電潜像を形成し、トナーにより可視画像とした後に、電圧を印加したローラによりトナー像を転写材に転写するプロセスを持つ。
【０１１５】
【発明の実施の形態】
以下、本発明をトナー製造例及び実施例により具体的に説明するが、これは本発明をなんら限定するものではない。
【０１１６】
＜シアントナーの製造例１＞
本発明に用いるシアントナーは、次の如くして調製した。
【０１１７】
高速撹拌装置ＴＫ−ホモミキサーを備えた２リットル用四つ口フラスコ中に、イオン交換水１０００質量部と０．１モル／リットル−Ｎａ３ＰＯ４水溶液４００質量部を添加し、回転数を１５０００ｒｐｍに調整し、６５℃に加温せしめた。ここに１．０モル／リットル−ＣａＣｌ_２水溶液８０質量部を徐々に添加し微小な難水溶性分散剤Ｃａ_３（ＰＯ_４）_２を含む分散媒系を調製した。
【０１１８】
一方、分散質系は、
・スチレン単量体 １５５質量部
・２−エチルヘキシルアクリレート単量体 ４５質量部
・ピグメントブルー１５：３ １５質量部
・飽和ポリエステル樹脂 ８質量部
（ビスフェノールＡとテレフタル酸との重縮合物、酸価１２、
ガラス転移点６０℃）
・ジアルキルサリチル酸アルミ化合物（オリエント化学製，商品名Ｅ８８）２質量部
・ジビニルベンゼン ０．４質量部
・低軟化点物質 ２５質量部
（ポリエチレンワックス、Ｍｗ＝１３００，Ｍｎ＝１０００，
Ｍｗ／Ｍｎ＝１．３）
上記混合物をアトライターを用い３時間分散させた後、重合開始剤であるｔ−ブチルヒドロペルオキシド４質量部を添加した分散物を、上記分散媒中に投入し回転数を維持しつつ１２分間造粒した。その後高速撹拌器からプロペラ撹拌羽根に撹拌機を変え５０ｒｐｍで重合を３時間継続させた後、１時間かけて８０℃に昇温し、その後６時間重合を継続した。
【０１１９】
重合終了後スラリーを冷却し、希塩酸を添加し分散剤を溶解させて濾過、水洗、乾燥をしてシアン粒子（１）を得た。得られたシアン粒子（１）をフロー式粒子像測定装置を用いて円形度分布および粒度分布を測定したところ、平均円形度は０．９８３であった。
【０１２０】
得られたシアン粒子（１）１００質量部に対し、ヘキサメチルジシラザンにより疎水化処理を行ったアルミナ微粉末（一次粒径２００ｎｍ；ＢＥＴ比表面積９．０）を０．２質量部、およびジメチルシリコーンオイルにより疎水化処理を行ったシリカ微粉末（一次粒径１２ｎｍ；ＢＥＴ比表面積１２０）を１．３質量部加え、三井鉱山社製ヘンシェルミキサーＦＭ１０Ｃを用いて３５００ｒｐｍで５分間均一拡散しシアントナー（１）を得た。物性を表１に示す。
【０１２１】
＜イエロー、マゼンタおよびブラックトナーの製造例１＞
シアントナーの製造例１においてピグメントブルー１５：３のかわりにピグメントイエロー９３、ピグメントレッド１２２、およびカーボンブラックにかえて製造例１と同様の製造条件でイエロートナー１、マゼンタトナー１、ブラックトナー１を製造した。
【０１２２】
各トナーはシアントナー１と同様の物性値を示した。
【０１２３】
＜シアントナーの製造例２乃至１１および１３＞
表１に示すように物性値や外添処方を変えることによりシアントナー２乃至１１および１３を製造した。諸物性を表１に示す。
【０１２４】
＜シアントナーの製造例１２＞
スチレン−２−エチルヘキシルアクリレート−ジビニルベンゼン共重合体
（ガラス転移点６５℃） １００質量部
フタロシアニン顔料 ７質量部
（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｂｌｕｅ１５：３）
飽和ポリエステル樹脂 ５質量部
（ビスフェノールＡとテレフタル酸との重縮合物、酸価１０ ガラス転移点６５℃）
ジアルキルサリチル酸アルミ化合物（オリエント化学製，商品名Ｅ８８）１質量部
低軟化点物質 ８質量部
（ポリエチレンワックスＭｗ＝１３００，Ｍｎ＝１０００，Ｍｗ／Ｍｎ＝１．３）
上記混合物をヘンシェルミキサーで予備混合し、二軸押出混練機により温度１３０℃にて溶融混練し、冷却後、ハンマーミルを用いて粗粉砕し、次いでエアージェット方式による微粉砕機で粉砕した。これを分級してシアン粒子（２）を得た。この時、粒子の平均円形度は０．９３１であった。
【０１２５】
このシアン粒子（２）に対し、製造例１と同様に外添を行いシアントナー１２を得た。諸物性を表１に示す。
【０１２６】
＜イエロー、マゼンタおよびブラックトナーの製造例２乃至１４＞
表１に示すようにシアントナー２乃至１４を製造したと同様の製造方法でピグメントブルー１５：３のかわりにピグメントイエロー９３、ピグメントレッド１２２、およびカーボンブラックにかえてイエロートナー２乃至１４、マゼンタトナー２乃至１４、ブラックトナー２乃至１４を製造した。各トナーはシアントナー２乃至１４と同様の物性値を示した。
【０１２７】
（実施例１）
製造例１で得られたトナーは、各色ごとに図１に示した現像器に充填し、４色のプロセスカートリッジとした。
【０１２８】
以上のカートリッジを用いて、１５℃／１０％ＲＨの低温低湿環境（Ｌ／Ｌ）および３０℃／８０％ＲＨの高温高湿環境下（Ｈ／Ｈ）において、以下の評価方法に基づいて７５ ｇ／ｍ２ Ａ４普通紙１５０００枚連続プリント試験を行った。図２に示したようなフルカラー画像形成装置において、プリント速度をＡ４横１６枚／分とし、紙面積に対するプリント比率２％とした。
【０１２９】
なお、以下の評価方法に基づいたプリント初期の評価結果は、全て良好であった。
【０１３０】
結果を表２および３に示す。
【０１３１】
［現像性評価方法］
（画像濃度変化）
画像濃度はマクベス濃度計またはカラー反射濃度計（例えばＣｏｌｏｒｒｅｆｌｅｃｔｉｏｎ ｄｅｎｓｉｔｏｍｅｔｅｒ Ｘ−ＲＩＴＥ ４０４Ａｍａｎｕｆａｃｔｕｒｅｄ ｂｙ Ｘ−Ｒｉｔｅ Ｃｏ．）で測定する。
【０１３２】
初期濃度と一万枚耐久後の濃度の差で評価する。
【０１３３】
Ａ：０．１％以下
Ｂ：０．１％を超え０．２％以下
Ｃ：０．２％を超え０．３％以下
Ｄ：０．３％を超える
（カブリの測定）
カブリの測定は、ＲＥＦＬＥＣＴＯＭＥＴＥＲ ＭＯＤＥＬ ＴＣ−６ＤＳ（東京電色社製）を用い測定し、下記式により算出した。カブリ値は少ない方が良好である。
【０１３４】
カブリ（反射率；％）＝
（標準紙の反射率；％）−（サンプルの白べた部の反射率；％）
Ａ：１．２％以下
Ｂ：１．２％を超え１．６％以下
Ｃ：１．６％を超え２．０％以下
Ｄ：２．０％を超える
（帯電量変化）
帯電量変化は、現像容器内の現像剤の耐久初期及び１万枚通紙後の帯電量値の変化量を下記評価基準に基づいて評価した。
【０１３５】
Ａ：変化量が１０％以下。
【０１３６】
Ｂ：変化量が１０％を超え１５％以下。
【０１３７】
Ｃ：変化量が１５％を超え２０％以下。
【０１３８】
Ｄ：変化量が２０％を超える。
【０１３９】
（帯電ローラ汚れ）
帯電ローラ汚れは、ローラ表面を目視で観察し、さらに画像欠陥を観察し、下記評価基準に基づいて評価した。
【０１４０】
Ａ：ローラ表面、画像ともに欠陥は全く認められない。
【０１４１】
Ｂ：耐久後半、ローラ表面に汚れが若干認められるが、画像には現れない。
【０１４２】
Ｃ：耐久後半、ローラ表面に汚れが若干認められ、画像にも若干のムラが生ずる。
【０１４３】
Ｄ：耐久後半、ローラ表面の汚れがひどく、画像にもムラが生ずる。
【０１４４】
（転写効率）
転写効率は、１万枚通紙後の現像剤を図１に示す画像形成装置を用い、Ｎ／Ｎ条件下、感光体に現像したトナー坪量に対する紙上に転写したトナー坪量の割合を下記評価基準に基づいて評価した。
【０１４５】
Ａ：９０％以上。
Ｂ：８０％を超え９０％未満。
Ｃ：７０％を超え８０％未満。
Ｄ：７０％未満。
【０１４６】
（ベタ均一性）
得られた転写紙上のベタ部画像は５点の濃度差でＡ、Ｂ、Ｃ、Ｄと評価した。
【０１４７】
Ａ：０．１％以下
Ｂ：０．１％を超え０．２％以下
Ｃ：０．２％を超え０．３％以下
Ｄ：０．３％を超える
（ドラム融着）
ドラム融着は、ドラム表面を目視で観察し、さらに画像欠陥を観察し、下記評価基準に基づいて評価した。
【０１４８】
Ａ：ドラム表面、画像ともに欠陥は全く認められない。
【０１４９】
Ｂ：耐久後半、ドラム表面に汚れが若干認められるが、画像には現れない。
【０１５０】
Ｃ：耐久後半、ドラム表面に汚れが若干認められ、画像にも若干のムラが生ずる。
【０１５１】
Ｄ：耐久後半、ドラム表面の汚れがひどく、画像にもムラが生ずる。
【０１５２】
（実施例２乃至１１）
実施例１にかえて表２および３に示すトナーおよびローラ構成において実施例１と同様の評価を行った。結果を表２および３に示す。
【０１５３】
（比較例１乃至１０）
実施例１にかえて表２および３に示すトナーおよびローラ構成において実施例１と同様の評価を行った。結果を表２および３に示す。
【０１５４】
【表１】

【０１５５】
【表２】

【０１５６】
【表３】

【０１５７】
【発明の効果】
本発明によれば、高温低湿環境下でも、低温低湿環境下でも、トナー劣化抑制に優れ、部材汚染抑制に優れた画像形成方法および現像剤が得られる。
【図面の簡単な説明】
【図１】本発明に適用されうる画像形成装置の一例を示す概略説明図である。
【図２】本発明に適用されうる画像形成装置の一例を示す概略説明図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner, an image forming method, and a process cartridge used in a recording method using an electrophotographic method, an electrostatic recording method, a toner jet recording method, or the like. More specifically, the present invention relates to a non-magnetic one-component toner used for a copying machine, a printer, a facsimile, which forms an image by forming a toner image on an electrostatic latent image carrier in advance and then transferring the image on a transfer material, an image forming method, and a process cartridge. .
[0002]
[Prior art]
In recent years, devices using electrophotography have been applied to devices such as printers and fax machines in addition to conventional copying machines. In particular, in a printer or a fax machine, since the size of the copying apparatus needs to be reduced, a developing apparatus using a one-component developer is often used.
[0003]
The one-component developing method using a one-component developer includes applying a charge to the toner particles by friction between the toner regulating member and the toner particles and friction between the toner carrier and the toner particles, and simultaneously applying the toner thinly on the toner carrier to carry the toner. This is a method in which the latent image carrier is conveyed to a development area where the body and the latent image carrier are opposed to each other, and the electrostatic latent image on the latent image carrier is developed to be visualized as a toner image.
[0004]
Unlike the two-component development method, the one-component development method does not require carrier particles such as glass beads, iron powder, and ferrite, so that the development device itself can be reduced in size and weight. Further, in the two-component developing method, since it is necessary to keep the toner concentration in the developer constant, a device for detecting the toner concentration and replenishing a required amount of toner is required, which results in an increase in the size and weight of the developing device. Also in this regard, the one-component developing method is advantageous in reducing the size and weight.
[0005]
However, in the one-component developing method, since there is no carrier particle, toner deterioration and member contamination due to the durability of a large number of sheets tend to be more severe than in the two-component developing method.
[0006]
The one-component development method is roughly classified into a magnetic one-component development method using a magnetic toner containing a magnetic material in a toner and a non-magnetic one-component development method using no magnetic material. A non-magnetic one-component developing method in which a toner can be used is used.
[0007]
In general, in a non-magnetic one-component developing method, toner is supplied onto a toner carrier by an elastic roller which is in contact with the toner carrier, and then the toner is thinly applied onto the toner carrier by a toner regulating member, and simultaneously toner regulation is performed. The toner particles are charged by friction with the member and friction with the toner carrier.
[0008]
Further, among non-magnetic one-component developing methods, there is a method in which a latent image carrier and a toner carrier are brought into contact with each other to improve development characteristics. (For example, refer to Patent Document 1).
[0009]
However, this non-magnetic one-component contact developing method causes a large physical stress on the toner, and further improvement in suppressing toner deterioration is expected.
[0010]
Further, there is disclosed a developing device in which a developing property and a transferring property are improved in a non-magnetic one-component contact developing method. (For example, see Patent Document 2).
[0011]
However, this effect is limited to the latent image carrier and the toner carrier. According to the study of the present inventors, the toner is transferred between contact members such as a charging process using a charging roller and a transfer process using an intermediate transfer body. In an image forming apparatus or the like which passes a large number of times, the number of sheets is not sufficient in terms of durability and toner fluidity, and an image forming apparatus and a developer further improved are expected.
[0012]
[Patent Document 1]
JP-A-2-61652
[Patent Document 2]
JP-A-3-259161
[0013]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a toner, a color toner and an image forming method which solve the problems of the prior art as described above.
[0014]
That is, an object of the present invention is to provide a toner and an image forming method with less toner deterioration.
[0015]
Another object of the present invention is to provide a toner and an image forming method with less contamination of members.
[0016]
[Means for Solving the Problems]
The electrostatic image carrier is charged by a charging member in contact therewith, an electrostatic image is formed on the charged electrostatic image carrier, and the toner carrier is brought into contact with the latent image carrier to form on the latent image carrier. Developing means for developing the electrostatic latent image by developing the toner by the action of an electric field, wherein the toner image is transferred to the intermediate transfer body by a member that comes into contact with the intermediate transfer body, The full-color image is transferred to the transfer material by a member that contacts the transfer material to form a full-color image, the full-color image is collectively transferred to the transfer material, and further fixed, the image forming method includes: The diameter R (D) of the charging member and the diameter R (c) of the charging member are represented by the following relational expressions.
20 mm ≦ R (D) ≦ 50 mm, 5 mm ≦ R (c) ≦ 15 mm,
2.0 <R (D) / R (c) <4.0
And the diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are defined by the following relational expression.
20 mm ≦ R (D) ≦ 50 mm, 10 mm ≦ R (d) ≦ 20 mm,
1.5 <R (D) / R (d) <4.0
A non-magnetic one-component toner applied to an image forming method satisfying the following condition, wherein the toner comprises at least toner particles comprising a binder resin, a colorant and a release agent, and an external additive. The toner contains at least one silica fine powder treated with silicone oil as an agent and has an average circularity of 0.95 in the number-based circle equivalent diameter-circularity scattergram measured by a flow type particle image measuring apparatus of 0.95. To 1.00, the weight average particle diameter A of the toner is 3 to 9 μm, and the BET specific surface area B is 1.2 to 3.3 (m ² / G) and the product A × B is 5 to 25, and a non-magnetic one-component toner.
[0017]
First, the diameter R (D) of the latent image carrier and the diameter R (c) of the charging member are represented by the following relational expressions.
2.0 <R (D) / R (c) <4.0
In this case, the balance between toner deterioration and image quality can be balanced. When R (D) / R (c) is 2.0 or less, the contact nip (area) between the latent image carrier and the charging member increases, and the toner and external additives remaining on the latent image carrier are easily rubbed. Image defects such as fusion will occur.
[0018]
When R (D) / R (c) is 4.0 or more, the peripheral diameter of the charging member is too small with respect to the peripheral diameter of the latent image carrier, and the toner and external additives slightly remaining on the latent image carrier. Accumulates on the charging member to cause image defects, or the charging is likely to be insufficient due to the narrow contact nip.
[0019]
In the present invention, it is preferable that 2.6 <R (D) / R (c) <3.5, because the above-mentioned effects are increased and the balance between toner deterioration and image quality is balanced.
[0020]
On the other hand, the physical properties of the toner used include at least toner particles comprising a binder resin, a colorant and a release agent and an external additive, and at least one type of silica fine powder treated with silicone oil as the external additive. The toner has an average circularity of 0.95 to 1.00 in a number-based circle equivalent diameter-circularity scattergram measured by a flow type particle image measuring apparatus, and a weight average particle diameter of the toner. A is 3 to 9 μm, and BET specific surface area B is 1.2 to 3.3 (m ² / G), and when the product A × B is 5 to 25, more balanced performance can be exhibited.
[0021]
Next, the diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are represented by the following relational expression.
1.5 <R (D) / R (d) <4.0
In this case, the balance between toner deterioration and image quality can be balanced. When R (D) / R (d) is 1.5 or less, the contact nip (area) between the latent image carrier and the toner carrier increases, and the toner and external additives existing on the toner carrier are easily rubbed. That is, an image defect such as roughness occurs due to toner deterioration.
[0022]
If R (D) / R (d) is 4.0 or more, the circumference of the toner carrier is too small relative to the circumference of the latent image carrier, and toner and external additives accumulate on the outermost layer of the toner carrier. Image defects, and the insufficient contact nip tends to result in insufficient development.
[0023]
In the present invention, it is preferable that 1.9 <R (D) / R (d) <3.5, because the above-described effects are increased and the balance between toner deterioration and image quality is balanced.
[0024]
On the other hand, the toner to be used has at least toner particles comprising a binder resin, a colorant and a release agent and an external additive, and contains at least one or more silica fine powder treated with silicone oil as the external additive. The average circularity of the toner in the number-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring device is 0.95 to 1.00, and the weight average particle size A of the toner is 3 to 9 μm, and the BET specific surface area B is 1.2 to 3.3 (m ² / G), and when the product A × B is 5 to 25, more balanced performance can be exhibited.
[0025]
The synergistic effect of the toner will be described in detail. First, when at least one kind of silica fine powder treated with silicone oil is contained as the external additive, a synergistic effect of reducing toner adhesion at each roller nip can be obtained.
[0026]
Examples of the oil to be subjected to the hydrophobic treatment include silicone oil, fluorine oil, and various modified oils. In the present invention, silicone oil is preferable. Examples of the silicone oil include those represented by the following formula.
[0027]
Embedded image

[0028]
[In the formula, R represents a C1-3 alkyl group, R ′ represents a silicone oil-modified group such as alkyl, halogen-modified alkyl, phenyl and modified phenyl, and R ″ represents a C1-3 alkyl group or alkoxy group. Shown.]
Examples include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil. The silicone oil has a viscosity at 25 ° C. of 50 to 100 mm. ² / S is preferably used.
[0029]
When the amount of treatment with the oil is 3 to 35 parts by mass with respect to 100 parts by mass of the base of the fine powder, the image forming apparatus of the present invention has good developing characteristics.
[0030]
If the oil processing amount is less than 3 parts by mass, the effect of preventing contamination of the member is hardly exhibited.
[0031]
If the oil processing amount exceeds 35 parts by mass, the processed external additive tends to aggregate, and the chargeability and developability of the toner become non-uniform.
[0032]
In the case of the present invention, when the amount is 5 to 25 parts by mass, the developing characteristics in the image forming apparatus of the present invention are further improved.
[0033]
As the external additive used in the present invention, conventionally known ones can be used. However, in order to improve developability, fluidity and storage stability, it is preferable that the external additive is selected from silica, alumina, titania and their suboxides.
[0034]
For example, as the silica, both a dry process silica called a so-called dry process or a fumed silica produced by a vapor phase oxidation of a silicon halide and an alkoxide, and a wet silica manufactured from an alkoxide and a water glass can be used. However, dry silica having less silanol groups on the surface and inside the fine powder, and having less production residue is more preferable.
[0035]
In the case of using silica fine powder as an example, silica fine powder is produced by subjecting a silicon halide to gas phase oxidation, and the obtained silica fine powder is subjected to a hydrophobic treatment to produce a non-spherical silica fine powder. In particular, during gas phase oxidation, baking may be performed at such a high temperature that the primary particles of silica coalesce.
[0036]
In the present invention, the external additive may be subjected to a silane coupling treatment or a surface treatment for forming an alumina coating for the purpose of increasing the hydrophobicity and improving the operability of controlling the particle size and shape.
[0037]
Specifically, examples of the silane coupling agent include hexamethyldisilazane and those represented by the following formula (1).
[0038]
RmSiYn (1)
R: alkoxy group or chlorine atom
m: an integer from 1 to 3
Y: a hydrocarbon group containing an alkyl group, a vinyl group, a glucidoxy group, or a methacryl group
n: an integer from 1 to 3
As the compound represented by the above (1), for example, typically, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxy Examples thereof include propyltrimethoxysilane, isobutyltrimethoxysilane, n-butyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane.
[0039]
The silane coupling agent treatment method is a dry method in which a vaporized silane coupling agent is reacted with a cloud of fine powder by stirring, or a wet method in which the fine powder is dispersed in a solvent and the silane coupling agent is dropped. Can be processed.
[0040]
As a method of forming an alumina coating, a method of adding aluminum chloride, aluminum nitrate, aluminum sulfate or the like in an aqueous solution or a solvent and immersing and drying the fine particles, or hydrated alumina, hydrated alumina-silica, hydrated alumina-titania, The method can be carried out by adding hydrated alumina-titania-silica or hydrated alumina-titania-silica-zinc oxide, immersing the fine particles in the aqueous solution, and drying.
[0041]
In addition to the external additive used in the present invention, fine powder may be further added for adjusting the charge amount, assisting fluidity, and the like.
[0042]
For example, examples of the fluidity-imparting agent include metal oxides (silicon oxide, aluminum oxide, titanium oxide, and the like), carbon black, silica, and the like, and those subjected to a hydrophobic treatment are more preferable. As abrasives, metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, barium sulfate, etc.) , Calcium carbonate, etc.). Examples of the charge control particles include metal oxides (such as tin oxide, titanium oxide, zinc oxide, silicon oxide, and aluminum oxide) and carbon black.
[0043]
It is preferable that the external additive be contained in an amount of 0.8 parts by mass or more based on 100 parts by mass of the toner particles. In an image forming apparatus in which toner frequently passes between contact members, such as a charging process using a charging roller or a transfer process using an intermediate transfer body, it is possible to prevent toner deterioration due to rubbing of toner by a nip between members. Is the amount required for Further, the degree of aggregation of the toner is preferably 5 to 30%. Thus, in an image forming apparatus in which toner frequently passes between contact members, such as a charging process using a charging roller or a transfer process using an intermediate transfer member, it is possible to prevent toner deterioration due to rubbing of toner by a nip between members. In addition, transferability can be maintained.
[0044]
Further, in the particle size distribution of the toner according to the circle equivalent diameter measured by the flow type particle image analyzer, the average circularity is preferably 0.95 to 1.00. Here, the flow-type particle image measurement device is a device that statistically performs image analysis of particle imaging, and the average circularity is calculated from the arithmetic mean of the circularity obtained by the following equation using the device.
[0045]
(Equation 1)

[0046]
In the above equation, the perimeter of the particle projection image is the length of the contour obtained by connecting the edge points of the binarized particle image, and the perimeter of the equivalent circle is the binarized particle. This is the length of the circumference of a circle having the same area as the image.
[0047]
The equivalent circle diameter is the diameter of a circle having the same area as the area of the measured two-dimensional image of the particles.
[0048]
FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.) is used as a flow-type particle image measuring device.
[0049]
As a measurement method, 0.02 g of a measurement sample is added to 10 ml (20 ° C.) of a solution prepared by adding 0.1 to 0.5% by mass of a surfactant (preferably, contaminone manufactured by Wako Pure Chemical Industries, Ltd.) to ion-exchanged water. In addition, the mixture was uniformly dispersed to prepare a sample dispersion liquid.
[0050]
As a means for dispersing, an ultrasonic dispersing machine UM-50 manufactured by SMT Co. (vibrator is a titanium alloy chip of 5φ) is used, the dispersing time is 5 minutes, and the temperature of the dispersing medium does not reach 40 ° C. or more. And cooled.
[0051]
In the measurement, a range of 0.60 to 400 μm is divided into 226 channels, and in an actual measurement, particles are measured in a range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.
[0052]
When the average circularity is from 0.95 to 1.00, the transfer toner residue in the primary transfer and the secondary transfer is small, and the amount of toner and external additives that pass through the cleaning member is also small, and the effect of suppressing contamination of the member is high.
[0053]
On the other hand, when the average circularity is less than 0.95, the transfer toner residue in the primary transfer and the secondary transfer is large, and the amount of toner and external additives that pass through the cleaning member is increased, so that the contamination of the member proceeds.
[0054]
In the present invention, examples of a method for producing a toner having the above-mentioned specific average circularity include a method for mechanically or thermally spheroidizing toner particles produced by a pulverization method to produce a toner, and a method for producing a toner. A method of directly manufacturing a toner by a legal method is exemplified.
[0055]
Further, the toner has a weight average particle size A of 3 to 9 μm and a BET specific surface area B of the toner of 1.2 to 3.3 (m ² / G), and when the product A × B is 5 to 25, a synergistic effect of suppressing toner deterioration can be obtained.
[0056]
Here, the BET specific surface property of the toner is affected by the particle size and shape of the base particles, and further by the BET specific surface area and the amount of the external additive added to the base particles. In particular, the effect of the amount of the external additive is great, and it is necessary to adjust the amount of the external additive to have an appropriate BET specific surface area for a toner capable of withstanding many sheets.
[0057]
The BET specific surface area B of the toner is 1.2 (m ² / G), the amount of the external additive is too small, and image defects such as roughness tend to occur.
[0058]
On the other hand, the BET specific surface area B of the toner is 3.3 (m ² / G), the amount of the external additive is too large, or the toner has many irregularities, and the rate of change of the BET specific surface area between before and after the durability increases, which tends to cause image defects.
[0059]
In the case of the present invention, the BET specific surface area B of the toner is more preferably 1.5 to 3.0 (m2 / g).
[0060]
If the product A × B of the weight average particle size A of the toner and the BET specific surface area B of the toner is less than 5, the amount of the external additive is too small, and image defects such as roughness are likely to occur. If it exceeds 25, the amount of the external additive is too large, or the toner has many irregularities, and the rate of change of the BET specific surface area before and after the endurance becomes large, which tends to cause image defects.
[0061]
In the present invention, it is preferable that the product A × B of the weight average particle diameter A of the toner and the BET specific surface area B of the toner is 10 to 20, since a further synergistic effect of suppressing toner deterioration can be obtained.
[0062]
The measurement of the BET specific surface area in the present invention is carried out by using a degassing device VacuPrep 061 (manufactured by MicroMestic) and a BET measuring device Gemini 2375 (manufactured by MicroMestic). In the sample preparation procedure, first, after measuring the weight of an empty sample cell, the measurement sample is filled so as to be between 1 and 1.01 g, and the sample cell filled with the sample is placed in a degassing device. Set and degas at room temperature for 3 hours. After the degassing, the mass of the entire sample cell is measured, and the accurate mass of the sample is calculated from the difference from the empty sample cell. The procedure for measuring the BET specific surface area will be described. First, an empty sample cell is set in the balance port and the analysis port of the BET measuring device. Next, a Dewar bottle containing liquid nitrogen is set at a predetermined position, and P0 is measured by a saturated vapor pressure (P0) measurement command. After the P0 measurement is completed, the prepared sample cell is set in the analysis port, and after inputting the sample mass and P0, the measurement is started by the BET measurement command. Thereafter, the BET specific surface area is automatically calculated.
[0063]
Examples of the low softening point substance used in the toner of the present invention include paraffin wax, polyolefin wax, modified products thereof (eg, oxides and graft-treated products), higher fatty acids and metal salts thereof, amide waxes, ketones Waxes, ester waxes and the like can be mentioned, but when used for color toners, amide waxes and ester waxes are preferred because high crystallinity impairs OHP transmission.
[0064]
The low softening point substance is preferably blended in an amount of 0.5 to 30% by mass.
[0065]
If the compounding amount of the low softening point substance is less than the lower limit, the offset prevention effect tends to decrease, and if it exceeds the upper limit, the anti-blocking effect is reduced and the anti-offset effect is liable to be adversely affected, causing drum fusion and sleeve fusion. In particular, in the case of a polymerization toner production method, a toner having a wide particle size distribution tends to be produced.
[0066]
The low softening point substance used in the present invention has a weight average molecular weight (Mw) and a number average molecular weight (Mn) ratio (Mw / Mn) of 1 in a molecular weight distribution measured by GPC (gel permeation chromatography). It is preferably from 0.0 to 1.5.
[0067]
This indicates that the molecular weight distribution is sharper as the value of Mw / Mn of the low softening point substance is closer to 1.0. Specifically, it shows good melting characteristics when heat is applied at the time of fixing, exudes quickly to the toner surface, and shows good fixing characteristics. Thus, a synergistic effect can be obtained by combining with the control of the substance on the toner surface described above.
[0068]
In the molecular weight distribution of the low softening point substance measured by GPC (gel permeation chromatography), low softening occurs when the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is more than 1.5. The exudation of the point substance to the toner surface is delayed, and the fixing property is deteriorated.
[0069]
The molecular weight of the low softening point substance is measured by GPC under the following conditions.
[0070]
(GPC measurement conditions)
Equipment: GPC-150C (Waters)
Column: GMH-HT 30 cm 2 stations (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% ionol added)
Flow rate: 1.0 ml / min
Sample: 0.4 ml of 0.15% sample is injected
The measurement is performed under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared using a monodisperse polystyrene standard sample. Further, it is calculated by converting into polyethylene using a conversion formula derived from the Mark-Houwink viscosity formula.
[0071]
As the binder resin used in the toner of the present invention, the following binder resins can be used.
[0072]
For example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyl toluene and a substituted product thereof; a styrene-p-chlorostyrene copolymer, a styrene-vinyltoluene copolymer, and a styrene-vinylnaphthalene copolymer Styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Styrene-based copolymers such as ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride; phenol Resin; Naturally modified Enol resin; natural modified maleic acid resin; acrylic resin; methacrylic resin; polyvinyl acetate; silicone resin; polyester resin; polyurethane; polyamide resin; furan resin; epoxy resin; xylene resin; polyvinyl butyral; terpene resin; Petroleum resins can be used. Preferred binders include styrene copolymers and polyester resins.
[0073]
Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, and methacryl. Acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, monocarboxylic acid having a double bond such as acrylamide or a substitute thereof; for example, maleic acid, butyl maleate, Dicarboxylic acids having a double bond such as methyl maleate and dimethyl maleate and substituted products thereof; for example, vinyl esters such as vinyl chloride, vinyl acetate, and vinyl benzoate; for example, ethylene, propylene, Vinyl monomers such as ethylene olefins such as tylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether Are used alone or in combination of two or more.
[0074]
The styrene-based polymer or styrene-based copolymer may be cross-linked, or may be a mixed resin of a cross-linked resin and a non-cross-linked resin.
[0075]
As the crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; And divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups, alone or as a mixture.
[0076]
The amount of the crosslinking agent to be added is preferably 0.001 to 10 parts by mass based on 100 parts by mass of the polymerizable monomer.
[0077]
The toner of the present invention may contain a charge control agent.
[0078]
The following substances control the toner to be negatively charged.
[0079]
For example, organic metal compounds and chelate compounds are effective, and examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. In addition, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarenes, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene- An acryl-sulfonic acid copolymer, a non-metal carboxylic acid-based compound and the like can be mentioned. Further, a resin in which the charge control compound is pendant may be internally added to the toner.
[0080]
The following substances control the toner to be positively charged.
[0081]
For example, denatured products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Onium salts, such as phosphonium salts, and their lake pigments, triphenylmethane dyes and these lake pigments (as the lacking agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, Gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate Dioctyl tin borate, diorgano tin borate such as dicyclohexyl tin borate; can be used and these in combination singly or two or more kinds. Among these, a charge control agent such as a nigrosine-based or quaternary ammonium salt is particularly preferably used. Further, a resin in which the charge control compound is pendant may be internally added to the toner.
[0082]
These charge control agents are preferably used in an amount of 0.01 to 20 parts by mass (more preferably 0.5 to 10 parts by mass) based on 100 parts by mass of the resin component.
[0083]
As the colorant used in the present invention, a black colorant which is adjusted to black using a yellow / magenta / cyan colorant shown below in addition to carbon black as a colorant is used.
[0084]
As the yellow colorant, a compound represented by a condensed azo compound, an isoindolinone compound, an anthraquinone compound, an azo metal complex, a methine compound, an allylamide compound, or the like is used. Specifically, C.I. I. Pigment Yellow 3, 7, 10, 12, 13, 14, 15, 17, 23, 24, 60, 62, 74, 75, 83, 93, 94, 95, 99, 100, 101, 104, 108, 109, 110 , 111, 117, 123, 128, 129, 138, 139, 147, 148, 150, 166, 168, 169, 177, 179, 180, 181, 183, 185, 191, 192, 170, 199, etc. Used. In addition, C.I. I. Solvent Yellow 33, 56, 79, 82, 93, 112, 162, 163, C.I. I. Disperse Yellow 42, 64, 201, 211 and the like. Further, if necessary, the yellow pigment and the dye may be used alone or in combination with the pigment and the dye.
[0085]
Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206 , 220, 221, 254 and C.I. I. Pigment Violet 19 is particularly preferred. Further, if necessary, a magenta pigment or a dye may be used alone, or a pigment and a dye may be used in combination.
[0086]
As the cyan coloring agent used in the present invention, 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, etc. can be particularly suitably used. If necessary, a cyan pigment or a dye may be used alone, or a pigment and a dye may be used in combination.
[0087]
These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, chroma, lightness, weather resistance, OHP transparency, and dispersibility in toner. The colorant is used in an amount of 1 to 20 parts by mass per 100 parts by mass of the resin.
[0088]
Next, a method for producing the toner used in the present invention will be described. The toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method.
[0089]
In the present invention, a method for producing a pulverized toner includes a binder resin, a low softening point substance, a pigment as a colorant, a dye or a magnetic substance, a charge control agent, and other additives as necessary, such as a Henschel mixer and a ball mill. The resulting mixture is melt-kneaded using a hot kneader such as a heating roll, a kneader, or an extruder, and the resin components are mixed with each other while a low softening point substance, a pigment, a dye, The magnetic material is dispersed or dissolved; the obtained kneaded material is solidified by cooling, and then pulverized and classified to obtain a toner.
[0090]
Further, if necessary, the toner and desired additives are sufficiently mixed by a mixer such as a Henschel mixer to obtain the toner used in the present invention.
[0091]
In the present invention, a method for producing a polymerized toner includes a method described in JP-B-56-13945 and the like, in which a molten mixture is atomized into air using a disk or a multi-fluid nozzle to obtain a spherical toner, and JP-B-36-10231. JP-A-59-53856, JP-A-59-61842, a method of directly producing a toner by using a suspension polymerization method, and a method of producing a toner which is soluble in a monomer. Either a dispersion polymerization method in which a toner is directly formed using an aqueous organic solvent in which the coalescence is insoluble, or an emulsion polymerization method typified by a soap-free polymerization method in which a toner is formed by directly polymerizing in the presence of a water-soluble polar polymerization initiator, or a primary polarity in advance. After the emulsion polymerized particles are formed, a toner can be produced by a heteroaggregation method or the like in which polar particles having the opposite charge are added and associated.
[0092]
However, in the dispersion polymerization method, although the obtained toner has an extremely sharp particle size distribution, the production equipment is not suitable from the viewpoints of narrow selection of materials to be used and utilization of an organic solvent from the viewpoint of waste solvent treatment and solvent flammability. It is complicated and easily complicated. The emulsion polymerization method represented by soap-free polymerization is effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and the terminal of the initiator are present on the surface of the toner particles, the environmental characteristics are easily deteriorated.
[0093]
Therefore, in the present invention, the suspension polymerization method under normal pressure or under pressure, which can relatively easily obtain a fine particle toner having a sharp particle size distribution, is particularly preferable. A so-called seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.
[0094]
When the direct polymerization method is used in the toner production method of the present invention, it is possible to specifically produce the toner by the following production method. A low-softening point substance, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the monomer, and the monomer system uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like is used as a dispersion stabilizer. Is dispersed in an aqueous phase containing the same by a conventional stirrer, homomixer, homogenizer or the like. Preferably, the agitation speed and time are adjusted so that the monomer droplets have the desired size of the toner particles, and granulation is performed. After that, by the action of the dispersion stabilizer, the stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction, and further, the second half of the reaction or the end of the reaction in order to remove unreacted polymerizable monomers and by-products which cause odor at the time of fixing the toner. Later, a part of the aqueous medium may be distilled off. After the reaction, the generated toner particles are collected 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 system.
[0095]
A more preferable toner used in the present invention is produced by a direct polymerization method in which a material having a low softening point is encapsulated in a shell resin layer by a tomography method of the toner using a transmission electron microscope (TEM). Things. Since it is necessary to incorporate a large amount of low softening point substance into the toner from the viewpoint of fixability, it is necessary to include a necessary low softening point substance in the outer shell resin. Unless the toner is not encapsulated, the toner cannot be sufficiently pulverized unless a special freeze-pulverization is used in the pulverization process, resulting in only a toner having a wide particle size distribution, and toner fusion to an apparatus occurs. It is very unfavorable. In the freezing and pulverization, the device becomes complicated to prevent dew condensation on the device, and if the toner absorbs moisture, the workability of the toner is reduced, and it is necessary to additionally provide a drying step, which causes a problem. As a specific method for encapsulating the low softening point substance, the polarity of the material in an aqueous medium is set to be smaller for the low softening point substance than for the main monomer, and a small amount of a large polar resin or simple resin is used. By adding the monomer, a toner having a so-called core-shell structure in which a low softening point substance is coated with an outer shell resin can be obtained. To control the particle size distribution and particle size of the toner, it is necessary to change the type and amount of the hardly water-soluble inorganic salt and the dispersant that acts as a protective colloid, and mechanical device conditions such as the peripheral speed of the rotor, the number of passes, and the stirring blade. The predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape, the shape of the container, and the solid content concentration in the aqueous solution.
[0096]
In the present invention, as a specific method for measuring the tomographic plane of the toner, a cured product obtained by thoroughly dispersing the toner in a room temperature curable epoxy resin and then curing the same in an atmosphere at a temperature of 40 ° C. for four days is used. After staining with ruthenium trioxide and, if necessary, osmium tetroxide, a flaky sample was cut out using a microtome with diamond teeth, and the tomographic morphology of the toner was measured using a transmission electron microscope (TEM). In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell.
[0097]
As a vinyl-based polymerizable monomer capable of undergoing radical polymerization used in producing a toner by a polymerization method, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.
[0098]
Monofunctional polymerizable monomers include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl Styrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p Styrene polymerizable monomers such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n -Hexyl acrylate, 2-ethylhexyl acrylate Acrylic polymerizable monomers such as acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl Methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl Methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl Methacrylic polymerizable monomers such as methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl methyl ether; Vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; and vinyl polymerizable monomers such as vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.
[0099]
Examples of polyfunctional polymerizable monomers include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tripropylene glycol. Diacrylate, polypropylene glycol diacrylate, 2,2'-bis [4- (acryloxydiethoxy) phenyl] propane, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis [4- (methacryloxy diethoxy) phenyl] propane, 2,2′-bis [4- (methacryloxypolyethoxy) phenyl] propane, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, divinylbenzene, divinylnaphthalene, divinylether and the like can be mentioned.
[0100]
The monofunctional polymerizable monomers can be used alone or in combination of two or more, or a monofunctional polymerizable monomer and a polyfunctional polymerizable monomer can be used in combination. Further, it is also possible to use the polyfunctional polymerizable monomer as a crosslinking agent.
[0101]
In the present invention, in order to form a core-shell structure in the toner, it is preferable to use a polar resin in combination. Examples of polar resins such as polar polymers and polar copolymers that can be used in the present invention are given below.
[0102]
Examples of the polar resin include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, or a copolymer of a nitrogen-containing monomer and a styrene-unsaturated carboxylic acid ester; a nitrile-based material such as acrylonitrile; Monomer; halogen-containing monomer such as vinyl chloride; unsaturated carboxylic acid such as acrylic acid and methacrylic acid; unsaturated dibasic acid; unsaturated dibasic acid anhydride; And a styrene-based monomer; a polyester; an epoxy resin. More preferred are a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated or unsaturated polyester resin, and an epoxy resin.
[0103]
Examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, and 1,1′-azobis (cyclohexane-1-carbonitrile) ), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumenehydro Peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,4-t-butylperoxycyclohexyl) propane, tris- (T-butylperoxy) A peroxide initiator such as riadin, a polymer initiator having a peroxide in a side chain, a persulfate such as potassium persulfate and ammonium persulfate, hydrogen peroxide, and the like are used.
[0104]
The polymerization initiator is preferably added in an amount of 0.5 to 20 parts by mass per 100 parts by mass of the polymerizable monomer, and may be used alone or in combination.
[0105]
In the present invention, a known crosslinking agent or chain transfer agent may be added to control the molecular weight, and the preferable addition amount is 0.001 to 15 parts by mass.
[0106]
In the present invention, any suitable stabilizer is used as a dispersion medium for producing a polymerization toner by emulsion polymerization, dispersion polymerization, suspension polymerization, seed polymerization, polymerization using a heteroaggregation method, or the like. I do. For example, as inorganic compounds, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and salts thereof, starch, polyacrylamide, polyethylene oxide, poly (hydroxystearic acid-g-methacrylic acid) A (methyl-eu-methacrylic acid) copolymer or a nonionic or ionic surfactant is used.
[0107]
When the emulsion polymerization method and the hetero-aggregation method are used, an anionic surfactant, a cationic surfactant, an amphoteric ionic surfactant and a nonionic surfactant are used. These stabilizers are preferably used in an amount of 0.2 to 30 parts by mass based on 100 parts by mass of the polymerizable monomer.
[0108]
When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, or the inorganic compound may be formed in a dispersion medium in order to obtain fine particles.
[0109]
Further, for fine dispersion of these stabilizers, 0.001 to 0.1 parts by mass of a surfactant may be used. This is to promote the intended action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, and lauryl acid. Sodium, potassium stearate, calcium oleate and the like.
[0110]
Next, an image forming apparatus preferable for the present invention will be described.
[0111]
(1) Example of image forming apparatus
FIG. 1 is a schematic diagram of a developing device using an electrophotographic process of a non-magnetic one-component contact developing system. In this embodiment, an apparatus modified from the following parts (a) to (h) was used.
(A) The process speed was changed to 85 mm / s.
(B) The charging method of the device was direct charging in contact with a rubber roller, and the applied voltage was a DC component (−450 V). (Diameter 9mm, ASKER-C hardness 60 degrees)
(C) The toner carrier was changed to a medium resistance rubber roller (diameter: 12 mm, ASKER-C hardness: 45 degrees) made of silicone rubber in which carbon black was dispersed, and was brought into contact with the photoconductor.
(D) The rotation of the toner carrier was in the same direction at the contact portion with the photoconductor, and the peripheral speed was driven to be 135 mm / s.
(E) The photoconductor was changed to the following.
[0112]
The photoreceptor used here was an Al cylinder as a substrate, and layers having the following structures were sequentially laminated by dip coating to prepare a photoreceptor. (25mm diameter)
(1) Conductive coating layer: mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenol resin. Film thickness 15 μm.
(2) Undercoat layer: mainly composed of modified nylon and copolymerized nylon. The film thickness is 0.6 μm.
(3) Charge generation layer: Mainly a charge generation layer in which a titanyl phthalocyanine pigment having absorption in a long wavelength region is dispersed in a butyral resin. The film thickness is 0.6 μm.
(4) Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 according to Ostwald viscosity method) at a mass ratio of 8:10. Film thickness 20 μm.
[0113]
The peripheral speed of the photoconductor was set at 85 mm / s.
(F) As a means for applying the toner to the toner carrier, an elastic roller made of urethane foam (50 to 100 cells per inch, ASKER-F hardness of 55 degrees, diameter of 16 mm) made of urethane foam is used in a developing machine. And brought into contact with the toner carrier. The rotation of the elastic roller was in the opposite direction at the contact portion with the toner carrier, and the peripheral speed was set at 95 mm / s.
(G) A resin-coated stainless steel blade was used to control the coating layer of the toner on the toner carrier.
(H) The applied voltage at the time of development was only DC component (-250 to -300 V).
[0114]
The modified device uniformly charges the image carrier using a roller charger (only DC is applied). After charging, an image is exposed with a laser beam to form an electrostatic latent image by exposing the image to a visible image with toner, and then the toner image is transferred to a transfer material by a roller to which a voltage is applied.
[0115]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to toner production examples and examples, but this does not limit the present invention in any way.
[0116]
<Production Example 1 of Cyan Toner>
The cyan toner used in the present invention was prepared as follows.
[0117]
In a two-liter four-necked flask equipped with a high-speed stirrer TK-homomixer, 1000 parts by mass of ion-exchanged water and 400 parts by mass of a 0.1 mol / L-Na3PO4 aqueous solution were added, and the number of revolutions was adjusted to 15,000 rpm. , 65 ° C. Here, 1.0 mol / liter-CaCl ₂ 80 parts by weight of an aqueous solution is gradually added, and fine minute water-insoluble dispersant Ca ₃ (PO ₄ ) ₂ Was prepared.
[0118]
On the other hand, the dispersoid system
・ Styrene monomer 155 parts by mass
・ 45 parts by mass of 2-ethylhexyl acrylate monomer
-Pigment Blue 15: 3 15 parts by mass
・ Saturated polyester resin 8 parts by mass
(Polycondensate of bisphenol A and terephthalic acid, acid value 12,
Glass transition point 60 ° C)
・ 2 parts by mass of aluminum dialkylsalicylate compound (manufactured by Orient Chemical Co., trade name: E88)
・ Divinylbenzene 0.4 parts by mass
・ Low softening point substance 25 parts by mass
(Polyethylene wax, Mw = 1300, Mn = 1000,
Mw / Mn = 1.3)
After the above mixture was dispersed for 3 hours using an attritor, a dispersion to which 4 parts by mass of t-butyl hydroperoxide as a polymerization initiator was added was poured into the above dispersion medium, and the dispersion was produced for 12 minutes while maintaining the rotation speed. Granulated. Thereafter, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and polymerization was continued at 50 rpm for 3 hours. Then, the temperature was raised to 80 ° C. over 1 hour, and then polymerization was continued for 6 hours.
[0119]
After completion of the polymerization, the slurry was cooled, diluted hydrochloric acid was added to dissolve the dispersant, and the mixture was filtered, washed with water and dried to obtain cyan particles (1). The circularity distribution and the particle size distribution of the obtained cyan particles (1) were measured using a flow-type particle image measurement device, and the average circularity was 0.983.
[0120]
To 100 parts by mass of the obtained cyan particles (1), 0.2 parts by mass of alumina fine powder (primary particle size: 200 nm; BET specific surface area: 9.0) subjected to hydrophobic treatment with hexamethyldisilazane, and dimethyl 1.3 parts by mass of silica fine powder (primary particle size: 12 nm; BET specific surface area: 120) subjected to hydrophobic treatment with silicone oil is added, and uniformly dispersed at 3500 rpm for 5 minutes using a Henschel mixer FM10C manufactured by Mitsui Mining Co., Ltd. (1) was obtained. Table 1 shows the physical properties.
[0121]
<Production Example 1 of Yellow, Magenta and Black Toner>
Yellow toner 1, magenta toner 1 and black toner 1 were manufactured under the same manufacturing conditions as in Manufacturing Example 1 except that Pigment Yellow 93, Pigment Red 122 and Carbon Black were used instead of Pigment Blue 15: 3 in Production Example 1 of cyan toner. Manufactured.
[0122]
Each toner exhibited the same physical property values as the cyan toner 1.
[0123]
<Production Examples 2 to 11 and 13 of cyan toner>
Cyan toners 2 to 11 and 13 were produced by changing the physical property values and the external additives as shown in Table 1. Table 1 shows various physical properties.
[0124]
<Production Example 12 of Cyan Toner>
Styrene-2-ethylhexyl acrylate-divinylbenzene copolymer
(Glass transition point 65 ° C) 100 parts by mass
7 parts by mass of phthalocyanine pigment
(CI Pigment Blue 15: 3)
5 parts by mass of saturated polyester resin
(Polycondensate of bisphenol A and terephthalic acid, acid value 10 Glass transition point 65 ° C)
1 part by mass of aluminum dialkylsalicylate compound (manufactured by Orient Chemical Co., trade name: E88)
Low softening point substance 8 parts by mass
(Polyethylene wax Mw = 1300, Mn = 1000, Mw / Mn = 1.3)
The mixture was preliminarily mixed with a Henschel mixer, melt-kneaded at a temperature of 130 ° C. with a twin-screw extruder, cooled, coarsely crushed using a hammer mill, and then crushed with an air jet fine crusher. This was classified to obtain cyan particles (2). At this time, the average circularity of the particles was 0.931.
[0125]
The cyan particles (2) were externally added in the same manner as in Production Example 1 to obtain a cyan toner 12. Table 1 shows various physical properties.
[0126]
<Production Examples 2 to 14 of yellow, magenta and black toners>
As shown in Table 1, yellow toners 2 to 14 and magenta toners were produced in the same manner as in the production of cyan toners 2 to 14, instead of pigment blue 15: 3, instead of pigment yellow 93, pigment red 122, and carbon black. Nos. 2 to 14 and black toners 2 to 14 were produced. Each toner exhibited the same physical property values as cyan toners 2 to 14.
[0127]
(Example 1)
The toner obtained in Production Example 1 was filled into the developing device shown in FIG. 1 for each color to form a four-color process cartridge.
[0128]
Using the above-described cartridge, under a low-temperature and low-humidity environment (L / L) of 15 ° C./10% RH and a high-temperature and high-humidity environment (H / H) of 30 ° C./80% RH, the following evaluation method was used. g / m2 A4 plain paper 15,000 sheets continuous printing test was performed. In the full-color image forming apparatus as shown in FIG. 2, the printing speed was set to A4 width 16 sheets / min, and the print ratio to the paper area was set to 2%.
[0129]
The initial evaluation results based on the following evaluation methods were all good.
[0130]
The results are shown in Tables 2 and 3.
[0131]
[Developability evaluation method]
(Change in image density)
The image density is measured with a Macbeth densitometer or a color reflection densitometer (for example, Colorreflection densitometer X-RITE 404 Amanufactured by X-Rite Co.).
[0132]
The evaluation is made based on the difference between the initial density and the density after 10,000 copies.
[0133]
A: 0.1% or less
B: More than 0.1% and 0.2% or less
C: more than 0.2% and 0.3% or less
D: Over 0.3%
(Measurement of fog)
The measurement of fog was measured using REFLECTOMETER MODEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.), and calculated by the following equation. The smaller the fog value, the better.
[0134]
Fog (reflectance;%) =
(Reflectance of standard paper;%)-(Reflectance of white solid portion of sample;%)
A: 1.2% or less
B: More than 1.2% and 1.6% or less
C: more than 1.6% and 2.0% or less
D: more than 2.0%
(Change in charge amount)
The change in the charge amount was evaluated based on the following evaluation criteria based on the change amount of the charge amount in the initial stage of the endurance of the developer in the developing container and after the passage of 10,000 sheets.
[0135]
A: The change amount is 10% or less.
[0136]
B: The change amount exceeds 10% and is 15% or less.
[0137]
C: The change amount exceeds 15% and is 20% or less.
[0138]
D: The amount of change exceeds 20%.
[0139]
(Charging roller dirt)
The contamination of the charging roller was evaluated by visually observing the roller surface, further observing image defects, and based on the following evaluation criteria.
[0140]
A: No defect is recognized on both the roller surface and the image.
[0141]
B: In the latter half of the durability, some dirt is observed on the roller surface, but does not appear in the image.
[0142]
C: In the latter half of the durability, the roller surface is slightly stained, and the image is slightly uneven.
[0143]
D: In the latter half of the endurance, the surface of the roller is heavily stained, and the image becomes uneven.
[0144]
(Transfer efficiency)
The transfer efficiency is defined as the ratio of the basis weight of the toner transferred on the paper to the basis weight of the toner developed on the photoconductor under N / N conditions using the image forming apparatus shown in FIG. The evaluation was based on the evaluation criteria.
[0145]
A: 90% or more.
B: More than 80% and less than 90%.
C: More than 70% and less than 80%.
D: Less than 70%.
[0146]
(Solid uniformity)
The resulting solid image on the transfer paper was evaluated as A, B, C, and D at five density differences.
[0147]
A: 0.1% or less
B: More than 0.1% and 0.2% or less
C: more than 0.2% and 0.3% or less
D: Over 0.3%
(Drum fusion)
The drum fusion was evaluated by visually observing the drum surface, further observing image defects, and based on the following evaluation criteria.
[0148]
A: No defect is recognized on both the drum surface and the image.
[0149]
B: In the latter half of the endurance, a slight stain is observed on the drum surface, but does not appear in the image.
[0150]
C: In the latter half of the endurance, the surface of the drum is slightly stained, and the image is slightly uneven.
[0151]
D: In the latter half of the endurance, the surface of the drum is heavily stained, and the image becomes uneven.
[0152]
(Examples 2 to 11)
The same evaluation as in Example 1 was performed using the toner and roller configurations shown in Tables 2 and 3 in place of Example 1. The results are shown in Tables 2 and 3.
[0153]
(Comparative Examples 1 to 10)
The same evaluation as in Example 1 was performed using the toner and roller configurations shown in Tables 2 and 3 in place of Example 1. The results are shown in Tables 2 and 3.
[0154]
[Table 1]

[0155]
[Table 2]

[0156]
[Table 3]

[0157]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the image forming method and the developer which are excellent in the suppression of toner deterioration and in the suppression of member contamination can be obtained both in a high-temperature and low-humidity environment and in a low-temperature and low-humidity environment.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an example of an image forming apparatus applicable to the present invention.
FIG. 2 is a schematic explanatory view showing an example of an image forming apparatus applicable to the present invention.

Claims (14)

The electrostatic image carrier is charged by a charging member in contact therewith, an electrostatic image is formed on the charged electrostatic image carrier, and the toner carrier is brought into contact with the latent image carrier to form on the latent image carrier. Developing means for developing the electrostatic latent image by developing the toner by the action of an electric field, wherein the toner image is transferred to the intermediate transfer body by a member that comes into contact with the intermediate transfer body, An image forming method in which the full-color image is transferred to the transfer material by a member that contacts the transfer material to form a full-color image, the full-color image is collectively transferred to the transfer material, and further fixed,
The diameter R (D) of the latent image carrier and the diameter R (c) of the charging member are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 5 mm ≦ R (c) ≦ 15 mm,
2.0 <R (D) / R (c) <4.0
Satisfied,
The diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 10 mm ≦ R (d) ≦ 20 mm,
1.5 <R (D) / R (d) <4.0
A non-magnetic one-component toner applied to an image forming method satisfying the following condition, wherein the toner comprises at least toner particles comprising a binder resin, a colorant and a release agent, and an external additive. Containing one or more silica fine powder treated with at least silicone oil as an agent,
The average circularity of the toner in the number-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring device is 0.95 to 1.00, and the weight average particle size A of the toner is 3 to A non-magnetic layer for an image forming method, having a BET specific surface area B of 1.2 to 3.3 (m ² / g) and a product A × B of 5 to 25. Component toner. The diameter R (D) of the latent image carrier and the diameter R (c) of the charging member are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 5 mm ≦ R (c) ≦ 15 mm,
2.6 <R (D) / R (c) <3.5
The toner according to claim 1, which satisfies the following. The diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 10 mm ≦ R (d) ≦ 20 mm,
1.9 <R (D) / R (d) <3.5
The toner according to claim 1, which satisfies the following. 4. The toner according to claim 1, wherein the toner contains at least 0.8 parts by mass of the external additive based on 100 parts by mass of the toner particles. The toner according to any one of claims 1 to 4, wherein the toner has a degree of aggregation of 5 to 30%. The BET specific surface area B of the toner is 1.5 to 3.0 (m ² / g), and the product A × B of the weight average particle diameter A and the BET specific surface area B is 10 to 20. The toner according to claim 1. The toner particles are produced by a polymerization method in which a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a solvent liquid in the presence of a polymerization initiator. Item 7. The toner according to any one of Items 1 to 6. The electrostatic image carrier is charged by a charging member in contact therewith, an electrostatic image is formed on the charged electrostatic image carrier, and the toner carrier is brought into contact with the latent image carrier to form on the latent image carrier. Developing means for developing the electrostatic latent image by developing the toner by the action of an electric field, wherein the toner image is transferred to the intermediate transfer body by a member that comes into contact with the intermediate transfer body, An image forming method for forming a full-color image by transferring the full-color image to the transfer material by a member in contact with the transfer material, transferring the full-color image to the transfer material at one time, and further fixing,
The diameter R (D) of the latent image carrier and the diameter R (c) of the charging member are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 5 mm ≦ R (c) ≦ 15 mm,
2.0 <R (D) / R (c) <4.0
Satisfied,
The diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 10 mm ≦ R (d) ≦ 20 mm,
1.5 <R (D) / R (d) <4.0
Wherein the toner has at least toner particles comprising a binder resin, a colorant and a release agent and an external additive, and the silica fine particles treated with at least a silicone oil as the external additive. The toner contains at least one powder, has an average circularity of 0.95 to 1.00 in a number-based circle equivalent diameter-circularity scattergram measured by a flow-type particle image measuring apparatus, and has a weight of 0.95 to 1.00. Non-magnetic one-component toner having an average particle size A of 3 to 9 μm, a BET specific surface area B of 1.2 to 3.3 (m ² / g), and a product A × B of 5 to 25 An image forming method characterized by using: The diameter R (D) of the latent image carrier and the diameter R (c) of the charging member are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 5 mm ≦ R (c) ≦ 15 mm,
2.6 <R (D) / R (c) <3.5
The image forming method according to claim 8, wherein the following formula is satisfied. The diameter R (D) of the latent image carrier and the diameter R (d) of the toner carrier are represented by the following relational expressions: 20 mm ≦ R (D) ≦ 50 mm, 10 mm ≦ R (d) ≦ 20 mm,
1.9 <R (D) / R (d) <3.5
The image forming method according to claim 8, wherein the following formula is satisfied. 11. The image forming method according to claim 1, wherein the toner contains an external additive in an amount of 0.8 parts by mass or more based on 100 parts by mass of the toner particles. 12. The image forming method according to claim 1, wherein the toner has a degree of aggregation of 5 to 30%. The BET specific surface area B of the toner is 1.5 to 3.0 (m ² / g), and the product A × B of the weight average particle diameter A and the BET specific surface area B is 10 to 20. The image forming method according to claim 1. The toner particles are produced by a polymerization method in which a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a solvent liquid in the presence of a polymerization initiator. Item 14. The image forming method according to any one of Items 1 to 13.

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