JP2004093764A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-particle diameter polymerization toner for electrostatic latent image development, which suppresses production of odor during thermal fixing, prevents problems of odor, and has an excellent fixing property, and to provide an image forming method using the toner. <P>SOLUTION: The toner comprises at least a resin and a coloring agent. The resin is prepared by polymerizing a radical polymerizable monomer in the presence of polyvalent chain transfer agent. The image forming method uses the toner. <P>COPYRIGHT: (C)2004,JPO

Description

【００７６】
【化２】

【００７７】
上記化合物の添加量は、トナー全体に対して１〜３０質量％、好ましくは２〜２０質量％、さらに好ましくは３〜１５質量％である。
【００７８】
荷電制御剤も同様に種々の公知のもので、且つ水中に分散することができるものを使用することができる。具体的には、ニグロシン系染料、ナフテン酸または高級脂肪酸の金属塩、アルコキシル化アミン、第４級アンモニウム塩化合物、アゾ系金属錯体、サリチル酸金属塩あるいはその金属錯体等が挙げられる。
【００７９】
なお、これら荷電制御剤や定着性改良剤の粒子は、分散した状態で数平均一次粒子径が１０〜５００ｎｍ程度とすることが好ましい。
【００８０】
いわゆる重合性単量体中に着色剤などのトナー構成成分を分散あるいは溶解したものを水系媒体中に懸濁し、ついで重合せしめてトナーを得る懸濁重合法トナーでは、重合反応を行う反応容器中での媒体の流れを制御することによりトナー粒子の形状を制御することができる。すなわち、形状係数が１．２以上の形状を有するトナー粒子を多く形成させる場合には、反応容器中での媒体の流れを乱流とし、重合が進行して懸濁状態で水系媒体中に存在している油滴が次第に高分子化することで油滴が柔らかい粒子となった時点で、粒子の衝突を行うことで粒子の合一を促進させ、形状が不定形となった粒子が得られる。また、形状係数が１．２より小さい球形のトナー粒子を形成させる場合には、反応容器中での媒体の流れを層流として、粒子の衝突を避けることにより球形の粒子が得られる。この方法により、トナー形状の分布を本発明の範囲内に制御できるものである。
【００８１】
懸濁重合法においては、特定の撹拌翼を使用することで、乱流を形成することができ、形状を容易に制御することができる。この理由としては明確では無いが一般的に使用されている図１（斜視図）に示される様な回転軸３に付けられた撹拌翼の構成が一段の撹拌槽２の場合には、撹拌槽内に形成される媒体の流れが撹拌槽の下部より上部へ壁面を伝って動く流れのみになる。そのため、従来では一般的に撹拌槽の壁面などに、撹拌を有効にするための乱流形成部材（邪魔板）９を配置することで乱流を形成し、撹拌の効率を増加することがなされている。しかし、この様な装置構成では、乱流が一部に形成されるものの、むしろ乱流の存在によって流体の流れが停滞する方向に作用し、結果として粒子に対するズリが少なくなるために、形状を制御することができないこともある。
【００８２】
好ましく使用することのできる撹拌翼を備えた撹拌槽について図を用いて説明する。図２は２段の撹拌翼を備えた撹拌槽の斜視図の一例である（但し、後記する如く、撹拌翼の形状は変えた方がよく、乱流形成部材もあった方がよい）。撹拌槽の外周部に熱交換用のジャケット１を装着した縦型円筒状の撹拌槽２内の中心部に回転軸３を垂設し、該回転軸３に撹拌槽２の底面に近接させて配設された下段の撹拌翼４と、より上段に配設された撹拌翼５がある。上段の撹拌翼５は、下段に位置する撹拌翼４に対して回転方向に先行した交差角αをもって配設されている。本発明においては交差角αは９０度（°）未満である。この交差角の下限は特に限定されるものでは無いが、５°程度以上、好ましくは１０°以上あればよい。これを上面断面図で示したのが図３である。もし３段以上の場合は、それぞれ隣接している撹拌翼間で交差角αが９０度未満であればよい。
【００８３】
この構成とすることで、上段に配設されている撹拌翼によりまず媒体が撹拌され、下側への流れが形成される。ついで、下段に配設された撹拌翼により、上段の撹拌翼で形成された流れがさらに下方へ加速されるとともにこの撹拌翼自体でも下方への流れが別途形成され、全体として流れが加速されて進行するものと推定される。この結果、乱流として形成された大きなズリ応力を有する流域が形成されるために、トナーの形状を制御できるものと推定される。
【００８４】
尚、図２中、矢印は回転方向を、７は上部材料投入口を８は下部材料投入口を表す。
【００８５】
ここにおいて撹拌翼の形状については、特に限定はないが、方形板状のもの、翼の一部に切り欠きのあるもの、中央部に一つ以上の中孔部分、いわゆるスリットがあるものなどを使用することができる。
【００８６】
これらの例を図４に記載する。図中（ａ）は撹拌翼に中孔部のないもの、（ｂ）は中央に大きな中孔部６があるもの、（ｃ）は横長の中孔部６があるもの、（ｄ）は縦長の中孔部６があるものである。又、これらは上段と下段で中孔部６が異なるものを用いても、同一のものを用いても良い。
【００８７】
また、この撹拌翼の構成として使用することができる好ましい構成の例を図５〜９に示す。図５は撹拌翼の端部に突起及び又は端部に折り曲げ部を有する構成、図６は下段の撹拌翼にスリットを有すると共に端部に折り曲げと突起を有する構成、図７は下段の撹拌翼の端部に突起と折り曲げを有する構成、図８は上段の撹拌翼にスリットがあり下段の撹拌翼の端部に折り曲げと突起を有する構成、図９は撹拌翼の構成が３段である構成をそれぞれ示したものである。なお、撹拌翼の端部に於ける折り曲げ部の角度は５〜４５°程度が好ましい。
【００８８】
これら折り曲げ部（４″または５″）や上部あるいは下部への突起（４′または５′）を有する構成を持つ撹拌翼は、乱流を効果的に発生するものである。
【００８９】
尚、上記の構成を有する上段と下段の撹拌翼の間隙は特に限定されるものでは無いが、少なくとも撹拌翼の間に間隙を有していることが好ましい。この理由としては明確では無いが、その間隙を通じて媒体の流れが形成されるため、撹拌効率が向上するものと考えられる。但し、間隙としては、静置状態での液面高さに対して０．５〜５０％の幅、好ましくは１〜３０％の幅である。
【００９０】
さらに、撹拌翼の大きさは特に限定されるものでは無いが、全撹拌翼の高さの総和が静置状態での液面高さの５０％〜１００％、好ましくは６０％〜９５％である。
【００９１】
又、懸濁重合法において層流を形成させる場合に使用される撹拌翼および撹拌槽の一例を図７に示す。撹拌槽内には乱流を形成させるような邪魔板等の障害物を設けないことが特徴である。撹拌翼の構成については、前述の乱流を形成させる場合に使用される撹拌翼と同様に、上段の撹拌翼が、下段の撹拌翼に対して回転方向に先行した交差角αを持って配設された、多段の構成とすることが好ましい。
【００９２】
この撹拌翼の形状については、乱流を形成させないものであれば特に限定されないが、図４（ａ）の方形板状のもの等、連続した面により形成されるものが好ましく、曲面を有していてもよい。
【００９３】
一方、樹脂粒子を水系媒体中で会合あるいは融着させる重合法トナーでは、融着段階での反応容器内の媒体の流れおよび温度分布を制御することで、さらには融着後の形状制御工程において加熱温度、撹拌回転数、時間を制御することで、トナー全体の形状分布および形状を任意に変化させることができる。
【００９４】
即ち、樹脂粒子を会合あるいは融着させる重合法トナーでは、反応装置内の流れを層流とし、内部の温度分布を均一化することができる撹拌翼および撹拌槽を使用して、融着工程および形状制御工程での温度、回転数、時間を制御することにより、本発明の形状係数および均一な形状分布を有するトナーを形成することができる。この理由は、層流を形成させた場で融着させると、凝集および融着が進行している粒子（会合あるいは凝集粒子）に強いストレスが加わらず、かつ流れが加速された層流においては撹拌槽内の温度分布が均一である結果、融着粒子の形状分布が均一になると推定される。さらに、その後の形状制御工程での加熱、撹拌により融着粒子は徐々に球形化し、トナー粒子の形状を任意に制御できる。
【００９５】
樹脂粒子を会合あるいは融着させる重合法トナーに使用される撹拌翼および撹拌槽としては、前述の懸濁重合法において層流を形成させる場合と同様のものが使用でき、例えば図７に示すものが使用できる。撹拌槽内には乱流を形成させるような邪魔板等の障害物を設けないことが特徴である。撹拌翼の構成については、前述の懸濁重合法に使用される撹拌翼と同様に、上段の撹拌翼が、下段の撹拌翼に対して回転方向に先行した交差角αを持って配設された、多段の構成とすることが好ましい。
【００９６】
この撹拌翼の形状についても、前述の懸濁重合法において層流を形成させる場合と同様のものが使用でき、乱流を形成させないものであれば特に限定されないが、図４（ａ）の方形板状のもの等、連続した面により形成されるものが好ましく、曲面を有していてもよい。
【００９７】
又、融着によって得られたトナーの形状は、下記式で示される形状係数の平均値（平均円形度）が０．９３０〜０．９８０、好ましくは０．９４０〜０．９７５であるのが好ましい。
【００９８】
形状係数＝（円相当径から求めた円周囲長）／（粒子投影像の周囲長）
又、形状係数の分布がシャープであることが好ましく、円形度の標準偏差は０．１０以下がよく、下記式で算出されるＣＶ値は２０％未満が好ましく、さらに１０％未満が好ましい。
【００９９】
ＣＶ値＝｛（円形度の標準偏差）／（平均円形度）｝×１００
この平均円形度を０．９３０〜０．９８０とすることで、トナーが有する形状をある程度不定形化することができ、熱の伝達を効率化することができ、定着性をより向上することができる。すなわち、平均円形度を０．９８０以下とすることで定着性を向上することができる。また、０．９３０以上の平均円形度とすることで、粒子の不定形度合いを抑制し、長期に渡る使用時のストレスによる粒子の破砕性を抑制することができる。
【０１００】
さらに、形状係数の分布がシャープであることが好ましく、円形度の標準偏差は０．１０以下とすることで形状が揃ったトナーとすることができ、トナー間での定着性能差を少なくすることができるため、定着率の向上及びオフセット性の低減による定着装置の汚染防止効果がより発揮される。また、ＣＶ値も２０％未満とすることで、同様にシャープな形状分布とすることができ、定着性向上効果をより顕著に発揮することができる。
【０１０１】
なお、上記形状係数の測定方法は限定されるものではないが、例えばトナー粒子を電子顕微鏡で５００倍に拡大した写真を撮影し、画像解析装置を使用し、５００個のトナーについて円形度を測定し、その算術平均値を求めることで、平均円形度を算出することができる。また、簡便な測定方法としては、ＦＰＩＡ−１０００（東亜医用電子株式会社製）により測定することができる。
【０１０２】
この形状に制御するためには会合などの工程で形状を制御されつつあるトナー粒子（着色粒子）の特性をモニタリングしながら適正な工程終了時期を決めてもよい。
【０１０３】
モニタリングするとは、インラインに測定装置を組み込みその測定結果に基づいて、工程条件の制御をするという意味である。すなわち、形状などの測定をインラインに組み込んで、例えば樹脂粒子を水系媒体中で会合あるいは融着させることで形成する重合法トナーでは、融着などの工程で逐次サンプリングを実施しながら形状や粒径を測定し、所望の形状になった時点で反応を停止する。
【０１０４】
モニタリング方法としては、特に限定されるものではないが、フロー式粒子像分析装置ＦＰＩＡ−２０００（東亜医用電子社製）を使用することができる。本装置は試料液を通過させつつリアルタイムで画像処理を行うことで形状をモニタリングできるため好適である。すなわち、反応場よりポンプなどを使用し、常時モニターし、形状などを測定することを行い、所望の形状などになった時点で反応を停止するものである。
【０１０５】
本発明のトナーの体積平均粒径はコールターカウンターＴＡ−ＩＩあるいはコールターマルチサイザー（コールター社製）で測定されるものである。本発明においてはコールターマルチサイザーを用い、粒度分布を出力するインターフェース（日科機製）、パーソナルコンピューターを接続して使用した。前記コールターマルチサイザーにおいて使用するアパーチャーとしては１００μｍのものを用いて、２μｍ以上のトナーの体積分布を測定して粒度分布および平均粒径を算出した。
【０１０６】
本発明のトナーの粒径は、体積平均粒径で３〜８μｍのものである。この粒径は、重合法によりトナー粒子を形成させる場合には、凝集剤の濃度や有機溶媒の添加量、または融着時間、さらには重合体自体の組成によって制御することができる。
【０１０７】
体積平均粒径が３〜８μｍであることにより、定着工程において、飛翔して加熱部材に付着しオフセットを発生させる付着力の大きいトナー微粒子が少なくなり、また、転写効率が高くなってハーフトーンの画質が向上し、細線やドット等の画質が向上する。
【０１０８】
測定条件
（１）アパーチャー：１００μｍ
（２）サンプル調製法：電解液〔ＩＳＯＴＯＮ　Ｒ−１１（コールターサイエンティフィックジャパン社製）〕５０〜１００ｍｌに界面活性剤（中性洗剤）を適量加えて撹拌し、これに測定試料１０〜２０ｍｇを加える。この系を超音波分散機にて１分間分散処理することにより調製する。
【０１０９】
又、本発明のトナーでは、外添剤として無機微粒子や有機微粒子などの微粒子を添加して使用することでより効果を発揮することができる。この理由としては、外添剤の埋没や脱離を効果的に抑制することができるため、その効果が顕著にでるものと推定される。
【０１１０】
この無機微粒子としては、シリカ、チタニア、アルミナ等の無機酸化物粒子の使用が好ましく、さらに、これら無機微粒子はシランカップリング剤やチタンカップリング剤等によって疎水化処理されていることが好ましい。疎水化処理の程度としては特に限定されるものでは無いが、メタノールウェッタビリティーとして４０〜９５のものが好ましい。メタノールウェッタビリティーとは、メタノールに対する濡れ性を評価するものである。
【０１１１】
この方法は、内容量２００ｍｌのビーカー中に入れた蒸留水５０ｍｌに、測定対象の無機微粒子を０．２ｇ秤量し添加する。メタノールを先端が液体中に浸せきされているビュレットから、ゆっくり撹拌した状態で無機微粒子の全体が濡れるまでゆっくり滴下する。この無機微粒子を完全に濡らすために必要なメタノールの量をａ（ｍｌ）とした場合に、下記式により疎水化度が算出される。
【０１１２】
疎水化度＝｛ａ／（ａ＋５０）｝×１００
この外添剤の添加量としては、トナー中に０．１〜５．０質量％、好ましくは０．５〜４．０質量％である。また、外添剤としては種々のものを組み合わせて使用してもよい。
【０１１３】
本発明のトナーは、例えば磁性体を含有させて一成分磁性トナーとして使用する場合、いわゆるキャリアと混合して二成分現像剤として使用する場合、非磁性トナーを単独で使用する場合等が考えられ、いずれも好適に使用することができるが、本発明ではキャリアと混合して使用する二成分現像剤として使用することが好ましい。
【０１１４】
二成分現像剤を構成するキャリアとしては、磁性粒子としては、鉄、フェライト、マグネタイト等の金属、それらの金属とアルミニウム、鉛等の金属との合金等の従来から公知の材料を用いることができる。特にフェライト粒子が好ましい。上記磁性粒子は、その体積平均粒径としては１５〜１００μｍ、より好ましくは２５〜６０μｍのものが良い。キャリアの体積平均粒径の測定は、代表的には湿式分散機を備えたレーザ回折式粒度分布測定装置「ヘロス（ＨＥＬＯＳ）」（シンパティック（ＳＹＭＰＡＴＥＣ）社製）により測定することができる。
【０１１５】
キャリアは、さらに樹脂により被覆されているもの、あるいは樹脂中に磁性粒子を分散させたいわゆる樹脂分散型キャリアが好ましい。コーティング用の樹脂組成としては、特に限定は無いが、例えば、オレフィン系樹脂、スチレン系樹脂、スチレン／アクリル系樹脂、シリコーン系樹脂、エステル系樹脂あるいはフッ素含有重合体系樹脂等が用いられる。また、樹脂分散型キャリアを構成するための樹脂としては、特に限定されず公知のものを使用することができ、例えば、スチレンアクリル樹脂、ポリエステル樹脂、フッ素系樹脂、フェノール樹脂等を使用することができる。
【０１１６】
次に、本発明に係わる画像形成装置の一例のカラー画像形成装置の断面構成図を図１０に示す。図１０において、２１は潜像担持体である感光体ドラムで、ＯＰＣ感光体（有機感光体）をドラム基体上に塗布形成したものであり、接地されて図示の時計方向に駆動回転される。２２は帯電手段たるスコロトロン帯電器で、感光体ドラム２１周面に対し高電位ＶＨの一様な帯電をグリッド電位ＶＧに電位保持されたグリッドとコロナ放電ワイヤによるコロナ放電によって与える。このスコロトロン帯電器による帯電に先だって、前プリントまでの感光体の履歴をなくすために発光ダイオード等を用いたＰＣＬ（帯電前除電器）による露光を行って感光体周面の除電をしておくとよい。
【０１１７】
感光体ドラム２１への一様帯電の後、露光手段２３により画像信号に基づいた像露光が行われる。露光手段２３は図示しないレーザーダイオードを発光光源とし回転するポリゴンミラー１３１、ｆθレンズ１３２、シリンドリカルレンズ１３３を経て反射ミラー１３４により光路を曲げられ主走査がなされるものである。
【０１１８】
感光体ドラム２１の回転（副走査）と同期して像露光がなされ潜像が形成される。本例では文字部に対して露光を行い、文字部の方が低電位ＶＬとなるような反転潜像を形成する。
【０１１９】
感光体ドラム２１の周縁には、イエロー（Ｙ）、マゼンタ（Ｍ）、シアン（Ｃ）、黒色（Ｋ）等のトナーとキャリアとから成る二成分現像剤をそれぞれ内蔵した現像手段２４Ｙ、２４Ｍ、２４Ｃ、２４Ｋが設けられている。
【０１２０】
画像形成プロセスを説明すると、先ず１色目として例えばイエローの現像が行われる。通常現像剤はフェライトをコアとしてそのまわりに絶縁性樹脂をコーティングしたキャリアと、ポリエステルを主材料として色に応じた顔料と荷電制御剤、シリカ、酸化チタン等を加えたトナーとからなる。現像剤は層形成手段によって現像スリーブ上に１００〜６００μｍの現像剤層厚に規制されて現像域へと搬送される。
【０１２１】
現像域における現像スリーブと感光体ドラム２１との間隙は現像剤層厚よりも大きい０．２〜１．０ｍｍとして、この間にＶＡＣのＡＣバイアスとＶＤＣのＤＣバイアスが重畳して印加される。ＶＤＣとＶＨ、トナーの帯電は同極性であるため、ＶＡＣによってキャリアから離脱するきっかけを与えられたトナーはＶＤＣより電位の高いＶＨの部分には付着せず、ＶＤＣより電位の低いＶＬ部分に付着し顕像化（反転現像）が行われる。
【０１２２】
１色目の顕像化が終った後２色目のマゼンタの画像形成工程にはいり、再びスコロトロン帯電器よる一様帯電が行われ、２色目の画像データによる潜像が露光手段２３によって形成される。
【０１２３】
再び感光体ドラム２１周面の全面に亘ってＶＨの電位となった感光体のうち、１色目の画像のない部分に対しては１色目と同様の潜像がつくられ現像が行われるが、１色目の画像がある部分に対し再び現像を行う部分では、１色目の付着したトナーにより遮光とトナー自身のもつ電荷によってＶＭ′の潜像が形成され、ＶＤＣとＶＭ′の電位差に応じた現像が行われる。この１色目と２色目の画像の重なりの部分では１色目の現像をＶＬの潜像をつくって行うと、１色目と２色目とのバランスが崩れるため、１色目の露光量を減らしてＶＨ＞ＶＭ＞ＶＬとなる中間電位ＶＭとすることもある。
【０１２４】
３色目のシアン、４色目の黒色についても２色目のマゼンタと同様の画像形成工程が行われ、感光体ドラム２１周面上には４色の顕像が形成される。
【０１２５】
一方、給紙カセットより半月ローラーを介して搬出された一枚の記録材（記録紙等）Ｐは、送り出しローラー対を経てレジストローラー対（給紙ローラー）近傍で一旦停止し、転写のタイミングの整った時点でレジストローラーの回転作動により転写域へと給紙される。
【０１２６】
転写域においては転写のタイミングに同期して感光体ドラム２１の周面に転写手段が圧接され、給紙された記録材Ｐを挟着して多色像が一括して転写される。
【０１２７】
次いで、記録材Ｐは分離手段によって除電され、感光体ドラム２１の周面より分離して定着装置（定着手段）４０に搬送され、加熱ローラー（上ローラー）４１と加圧ローラー（下ローラー）４２の加熱，加圧によってトナーを溶着したのち、排紙ローラーを経て装置外部の排紙トレイ上に排出される。なお、前記の転写手段は記録材Ｐの通過後感光体ドラム２１の周面より退避離間して、次なるトナー像の形成に備える。
【０１２８】
一方、記録材Ｐを分離した感光体ドラム２１は、除電器により除電を受けたのち、クリーニング手段２５のブレードの圧接により残留トナーを除去、清掃され、再び前記ＰＣＬによる除電とスコロトロン帯電器による帯電を受けて次なる画像形成のプロセスに入る。なお、前記のブレードは感光体面のクリーニング後、直ちに移動して感光体ドラム２１の周面より退避する。ブレードによってクリーニング手段２５内に掻き落された廃棄トナーは、スクリューにより排出されたのち、図示しない廃トナー回収容器内へ貯留される。
【０１２９】
本発明に使用される好適な定着方法としては、いわゆる接触加熱方式をあげることができる。特に、接触加熱方式として、熱圧定着方式、さらには熱ロール定着方式および固定配置された加熱体を内包した回動する加圧部材により定着する圧接加熱定着方式をあげることができる。
【０１３０】
熱ロール定着方式では、多くの場合表面にテトラフルオロエチレンやポリテトラフルオロエチレン−パーフルオロアルコキシビニルエーテル共重合体類等を被覆した鉄やアルミニウム等で構成される金属シリンダー内部に熱源を有する上ローラーとシリコーンゴム等で形成された下ローラーとから形成されている。熱源としては、線状のヒーターを有し、上ローラーの表面温度を１２０〜２００℃程度に加熱するものが代表例である。定着部に於いては上ローラーと下ローラー間に圧力を加え、下ローラーを変形させ、いわゆるニップを形成する。ニップ幅としては１〜１０ｍｍ、好ましくは１．５〜７ｍｍである。定着線速は４０ｍｍ／ｓｅｃ〜６００ｍｍ／ｓｅｃが好ましい。ニップが狭い場合には熱を均一にトナーに付与することができなくなり、定着のムラを発生する。一方でニップ幅が広い場合には樹脂の溶融が促進され、定着オフセットが過多となる問題を発生する。
【０１３１】
定着クリーニングの機構を付与して使用してもよい。この方式としてはシリコーンオイルを定着の上ローラーあるいはフィルムに供給する方式やシリコーンオイルを含浸したパッド、ローラー、ウェッブ等でクリーニングする方法が使用できる。
【０１３２】
上記定着器にはクリーニング機構を付与して使用してもよい。クリーニング方式としては、各種シリコーンオイルを定着用フィルムに供給する方式や各種シリコーンオイルを含浸させたパッド、ローラー、ウエッブ等でクリーニングする方式が用いられる。
【０１３３】
なお、シリコーンオイルとしては、ポリジメチルシロキサン、ポリメチルフェニルシロキサン、ポリジフェニルシロキサン等を使用することが出来る。さらに、フッ素を含有するシロキサンも好適に使用することが出来る。
【０１３４】
【実施例】
（ラテックス作製例１）
撹拌装置、温度センサー、冷却管、窒素導入装置を付けた５０００ｍｌのセパラブルフラスコに予めアニオン系活性剤（ドデシルベンゼンスルフォン酸ナトリウム：ＳＤＳ）７．０８ｇをイオン交換水（２７６０ｇ）に溶解させた溶液を添加する。窒素気流下２３０ｒｐｍの撹拌速度で撹拌しつつ、内温を８０℃に昇温させた。一方で例示化合物（２０）７２．０ｇをスチレン１１５．１ｇ、ｎ−ブチルアクリレート４２．０ｇ、メタクリル酸１０．９ｇからなるモノマーに加え、８０℃に加温し溶解させ、モノマー溶液を作製した。ここで循環経路を有する機械式分散機により上記の加熱溶液を混合分散させ、均一な分散粒子径を有する乳化粒子を作製した。ついで、重合開始剤（過硫酸カリウム：ＫＰＳ）０．８４ｇをイオン交換水２００ｇに溶解させた溶液を添加し８０℃にて３時間加熱、撹拌することでラテックス粒子を作製した。引き続いて更に重合開始剤（ＫＰＳ）７．７３ｇをイオン交換水２４０ｍｌに溶解させた溶液を添加し、１５分後、８０℃でスチレン３８３．６ｇ、ｎ−ブチルアクリレート１４０．０ｇ、メタクリル酸３６．４ｇ、多価連鎖移動剤（１３）５．０ｇの混合液を１００分かけて滴下した。滴下終了後６０分加熱撹拌させた後４０℃まで冷却しラテックス粒子を得た。このラテックス粒子をラテックス１とする。
【０１３５】
（ラテックス作製例２）
ラテックス作製例１において、多価連鎖移動剤（１３）の代わりに（１４）を８．０ｇを使用した他は同様にしてラテックス粒子を得た。これをラテックス２とする。
【０１３６】
（ラテックス作製例３）
ラテックス作製例１において、多価連鎖移動剤（１３）の代わりに（１６）を１５．０ｇ使用した他は同様にしてラテックス粒子を得た。これをラテックス３とする。
【０１３７】
（ラテックス作製例４）
ラテックス作製例１において、多価連鎖移動剤（１３）の代わりに（１８）を２．０ｇ使用した他は同様にしてラテックス粒子を得た。これをラテックス４とする。
【０１３８】
（ラテックス作製例５）
ラテックス作製例１において、多価連鎖移動剤（１３）の代わりに（７）を５．０ｇ使用した他は同様にしてラテックス粒子を得た。これをラテックス５とする。
【０１３９】
（ラテックス作製例６）
ラテックス作製例１において、多価連鎖移動剤（１３）の代わりにｔ−ドデシルメルカプタンを５．０ｇ使用した他は同様にしてラテックス粒子を得た。これをラテックス６とする。
【０１４０】
（トナー作製例）
着色粒子１Ｂｋの製造
ｎ−ドデシル硫酸ナトリウムの９．２ｇをイオン交換水１６０ｍｌに撹拌溶解する。この液に、撹拌下、リーガル３３０Ｒ（キャボット社製カーボンブラック）２０ｇを徐々に加え、ついで、クレアミックスを用いて分散した。大塚電子社製の電気泳動光散乱光度計ＥＬＳ−８００を用いて、上記分散液の粒径を測定した結果、質量平均径で１１２ｎｍであった。この分散液を「着色剤分散液１」とする。
【０１４１】
前述の「ラテックス１」１２５０ｇとイオン交換水２０００ｍｌ及び「着色剤分散液１」を、温度センサー、冷却管、窒素導入装置、攪拌装置を付けた５リットルの四つ口フラスコに入れ撹拌する。３０℃に調整した後、この溶液に５ｍｏｌ／Ｌの水酸化ナトリウム水溶液を加え、ｐＨを１０．０に調整した。ついで、塩化マグネシウム６水和物５２．６ｇをイオン交換水７２ｍｌに溶解した水溶液を攪拌下、３０℃にて１０分間で添加した。その後、３分間放置した後に、昇温を開始し、液温度９０℃まで６分で昇温する（昇温速度＝１０℃／分）。その状態で粒径をコールターカウンターＴＡＩＩにて測定し、体積平均粒径が６．５μｍになった時点で塩化ナトリウム１１５ｇをイオン交換水７００ｍｌに溶解した水溶液を添加し粒子成長を停止させ、さらに継続して液温度９０℃±２℃にて、６時間加熱撹拌し、塩析／融着させる。その後、６℃／ｍｉｎの条件で３０℃まで冷却し、塩酸を添加し、ｐＨを２．０に調整し、撹拌を停止した。生成した着色粒子を濾過し、イオン交換水で繰り返し洗浄し、その後、４０℃の温風で乾燥し、着色粒子を得た。以上のようにして得られた着色粒子を「着色粒子１Ｂｋ」とする。
【０１４２】
なお、その他の「ラテックス２」〜「ラテックス６」を使用し、以下に示すカーボンブラック及び着色剤に変更した他は同様にして表１に示す「着色粒子１Ｂｋ」〜「着色粒子６Ｃ」を得た。
【０１４３】
着色粒子１Ｙ
カーボンブラックの代わりにＣ．Ｉ．ピグメントイエロー１８５を使用した他は同様にして着色粒子を得た。これを「着色粒子１Ｙ」とする。
【０１４４】
着色粒子１Ｍ
カーボンブラックの代わりにＣ．Ｉ．ピグメントレッド１２２を使用した他は同様にして着色粒子を得た。これを「着色粒子１Ｍ」とする。
【０１４５】
着色粒子１Ｃ
カーボンブラックの代わりにＣ．Ｉ．ピグメントブルー１５：３を使用した他は同様にして着色粒子を得た。これを「着色粒子１Ｃ」とする。
【０１４６】
以下、着色粒子２群はラテックス２を使用し、ラテックス６まで使用して着色粒子１（Ｂｋ／Ｙ／Ｍ／Ｃ）〜着色粒子６（Ｂｋ／Ｙ／Ｍ／Ｃ）を調製した。
【０１４７】
（着色粒子製造例７Ｂｋ）：懸濁重合法の例
高速攪拌装置（ＴＫホモミキサー）を備えた４つ口フラスコにイオン交換水７１０質量部と０．１モル／リットルの燐酸三ナトリウム水溶液４５０質量部を加え、６５℃に加温し、回転数１２０００ｒｐｍの攪拌条件下に１．０モル／リットルの塩化カルシウム水溶液６８質量部を徐々に加え、コロイド状燐酸三カルシウムを含む分散液を含む水系分散媒体を調製した。ついで、スチレンモノマー１６５質量部、ｎ−ブチルアクリレート３５質量部にカーボンブラック（リーガル３３０Ｒ）１４質量部を加えサンドグラインダーで分散した分散液にエステルワックス（１９）を３０質量部加え、８０℃にて溶解させた。ついで多価連鎖移動剤（１３）を２質量部及び重合開始剤として、２，２′−アゾビス（２，４−ジメチルバレロニトリル）１０質量部を加えたものを前記水系分散媒体中に回転数１２０００ｒｐｍの攪拌条件下で徐々に加え、水中にモノマーを含む溶液を分散させた。ついで、攪拌翼の構成を図２とした反応装置を使用し、窒素気流下、６５℃、２００ｒｐｍ攪拌条件下で１０時間重合反応を行った。重合反応終了時に塩酸を加え、分散安定剤である燐酸三カルシウムを除去し、濾過、洗浄乾燥し、着色粒子を調製した。このものを「着色粒子７Ｂｋ」とする。なお、前記重合時にモニタリングを行い、液温度、攪拌回転数、および加熱時間を制御することにより、形状および形状係数の変動係数を制御し、さらに液中分級により、粒径および粒度分布の変動係数を任意に調整した。
【０１４８】
（着色粒子製造例８Ｂｋ）：懸濁重合法の例
着色粒子製造例７Ｂｋにおいて、多価連鎖移動剤（１３）の代わりに（１４）を３質量部使用した他は同様にして着色粒子を得た。これを着色粒子８Ｂｋとする。
【０１４９】
（着色粒子製造例９Ｂｋ）：懸濁重合法の例
着色粒子製造例７Ｂｋにおいて、多価連鎖移動剤（１３）の代わりに（１６）を３質量部使用した他は同様にして着色粒子を得た。これを着色粒子９Ｂｋとする。
【０１５０】
（着色粒子製造例１０Ｂｋ）：懸濁重合法の例
着色粒子製造例７Ｂｋにおいて、多価連鎖移動剤（１３）の代わりにｔ−ドデシルメルカプタンを使用した他は同様にして着色粒子を得た。これを着色粒子１０Ｂｋとする。
【０１５１】
【表１】

【０１５２】
【表２】

【０１５３】
表２において、円形度はＦＰＩＡ−１０００を使用し、試料分析量＝０．３μリットル、検出粒子数１５００〜５０００個の条件で測定したものである。なお、着色粒子６Ｂｋ、６Ｙ、６Ｍ、６Ｃ及び着色粒子１０Ｂｋは比較例である。
【０１５４】
ついで上記「着色粒子１Ｂｋ／１Ｙ／１Ｍ／１Ｃ」〜「着色粒子６Ｂｋ／６Ｙ／６Ｍ／６Ｃ」、「着色粒子７Ｂｋ」〜「着色粒子１０Ｂｋ」にそれぞれ疎水性シリカ（数平均一次粒子径＝１２ｎｍ、疎水化度＝７１）を１質量％及び疎水性酸化チタン（数平均一次粒子径＝２０ｎｍ、疎水化度＝６３）を１質量％添加し、ヘンシェルミキサーにより混合してトナーを得た。これらを「トナー１Ｂｋ／１Ｙ／１Ｍ／１Ｃ（着色粒子１群）」〜「トナー６Ｂｋ／６Ｙ／６Ｍ／６Ｃ（着色粒子６群）」、「トナー７Ｂｋ（着色粒子７）」〜「トナー１０Ｂｋ（着色粒子１０）」とする。
【０１５５】
【表３】

【０１５６】
なお、形状及び粒径等の物性に関しては着色粒子及びトナーのいずれも差異は無い。
【０１５７】
上記トナーの各々に対してシリコーン樹脂を被覆した体積平均粒径６０μｍのフェライトキャリアを混合し、トナー濃度が６％の現像剤を調製した。これらをトナーに対応して、「現像剤１Ｂｋ／１Ｙ／１Ｍ／１Ｃ（現像剤群１）」〜「現像剤６Ｂｋ／６Ｙ／６Ｍ／６Ｃ（現像剤群６）」、「現像剤７Ｂｋ（現像剤７）」〜「現像剤１０Ｂｋ（現像剤１０）」とする。
【０１５８】
ここで調製した現像剤を使用し、図１０に示すカラー複写機を用い定着器の構成を下記に示す構成に変更して実写評価を実施した。
【０１５９】
定着器としては図１１に示すごとき圧接方式の加熱定着装置を用いた。
具体的構成は下記の如くである。
【０１６０】
表面をＰＦＡ（テトラフロオロエチレン−パーフルオロアルキルビニルエーテル共重合体）の被覆層（厚み：１２０μｍ）１２を有し内径４０ｍｍで全幅が３１０ｍｍの、ヒーター１３を中央部に内蔵した円柱状の厚み１．０ｍｍのアルミ合金パイプ１１を加熱ローラー（上ローラー）４１として有し、表面が同様にスポンジ状シリコーンゴム（アスカーＣ硬度＝４８：厚み２ｍｍ）１７で構成された内径４０ｍｍの肉厚２．０ｍｍの鉄パイプ１６を有する加圧ローラー（下ローラー）４２を有している。ニップ幅は５．８ｍｍとした。この定着装置を使用して、印字の線速を２５０ｍｍ／ｓｅｃに設定した。
【０１６１】
なお、定着装置のクリーニング機構としてポリジフェニルシリコーン（２０℃の粘度が１０Ｐａ・ｓのもの）を含浸したウェッブ方式の供給方式を使用した。
【０１６２】
定着の温度は上ロールの表面温度で制御し、１７５℃の設定温度とした。なお、シリコーンオイルの塗布量は、０．６ｍｇ／Ａ４とした。
〔特性評価〕
定着性の評価は、Ｙ／Ｍ／Ｃ／Ｂｋがそれぞれ単色で印字されているＡ４のハーフトーン画像（画像濃度が紙の濃度を「０」としたときの相対反射濃度で１．０のもの）を印字し、定着率を測定した。定着率とは、定着画像を「サラシ布」を巻いた１ｋｇのおもりで擦り、その前後の画像濃度変化を百分率で算出したものである。
【０１６３】
定着率（％）＝（擦り後の画像濃度）／（擦り前の画像濃度）×１００
尚、加熱ローラーの表面温度はセンター値で１７０℃とした。
【０１６４】
また、床が５ｍ×５ｍ、高さが２ｍの密閉された部屋中で１７０℃の設定温度にて画素率が５０％のフルカラー画像を連続で千枚印字し、臭気の有無を官能評価にて実施した。臭気の有無については１０名の評価員を使用し、臭気を感じた人数で評価した。
【０１６５】
さらに、１０万枚の印字テストを実施し、定着部位からの汚染の有無を評価した。
【０１６６】
【表４】

【０１６７】
本発明内の実施例１〜８は、何れも良い特性を示すが、本発明外の比較例１と２は、臭気があり、１０万枚印字後の定着部位からの汚染があることがわかる。
【０１６８】
【発明の効果】
本発明により、いわゆる重合法の静電潜像現像用トナーにおいて、熱定着時の臭気の発生を抑え、臭気問題を発生することの無いしかも定着性に優れた、小粒径の静電潜像現像用トナーとそれを用いた画像形成方法を提供することが出来る。
【図面の簡単な説明】
【図１】従来の撹拌翼を備えた撹拌槽の一例の斜視図である。
【図２】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図３】図２の上面断面図である。
【図４】撹拌翼の形状の概要図である。
【図５】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図６】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図７】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図８】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図９】撹拌翼を備えた撹拌槽の一例の斜視図である。
【図１０】本発明におけるカラー画像形成装置の断面構成図である。
【図１１】本発明に係わる加熱定着装置の概略図である。
【符号の説明】
１　熱交換用のジャケット
２　撹拌槽
３　回転軸
４　下段の撹拌翼
５　上段の撹拌翼
６　中孔部
７　上部材料投入口
８　下部材料投入口
９　乱流形成部材
１１　アルミ合金パイプ
１２　テトラフロオロエチレン−パーフルオロアルキルビニルエーテル共重合体の被覆層
１３　ヒーター
１６　鉄パイプ
１７　スポンジ状シリコーンゴム
２１　感光体ドラム
２２　帯電手段
２３　露光手段
２４Ｙ、２４Ｍ、２４Ｃ、２４Ｋ　現像手段
２５　クリーニング手段
４０　定着装置
４１　加熱ローラー
４２　加圧ローラー
α　交差角
Ｐ　記録材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner and an image forming method.
[0002]
[Prior art]
When designing a resin for a toner, it is necessary to use a resin having a low molecular weight, that is, a resin having a low melt viscosity in order to improve the adhesiveness to paper. However, in this case, since the melt viscosity is low, there is a problem that an offset is easily induced at the time of fixing.
[0003]
In order to prevent offset during fixing, it is important to increase the molecular weight. Thereby, the elastic modulus of the resin can be improved, and the offset can be suppressed during fixing. However, in this case, since the melt viscosity of the resin also increases, there is a problem that the adhesiveness to paper decreases.
[0004]
On the other hand, it is desired that the toner for developing an electrostatic latent image is reduced in particle size from the viewpoint of high image quality and uniform in particle size. In recent years, polymerization toners have been actively developed as a method for producing such small particle size toners. The polymerized toner is prepared by associating or salting out / fusing resin particles and colorant particles to prepare an irregular shaped toner, or by dispersing a radical polymerizable monomer and a colorant, There is a method in which droplets are dispersed in a medium or the like so as to have a desired toner particle diameter and suspension polymerization is performed.
[0005]
In any case, as described above, it is necessary to adjust the molecular weight distribution in order to improve the fixing property. When a chain transfer agent is used to control the molecular weight distribution to reduce the molecular weight, mercaptans, particularly dodecyl mercaptan, are used as a suitable chain transfer agent. However, this material has a peculiar odor, and there is a problem that the chain transfer agent remaining at the time of heat fixing volatilizes and odor is generated.
[0006]
In a full-color image forming method in which a large amount of toner needs to be used, the improvement of the offset property is particularly important. That is, since a large amount of toner is used, it is necessary to improve the fixability itself, and for that purpose, it is necessary to reduce the molecular weight and improve the adhesiveness to paper. For this reason, it is necessary to use a chain transfer agent, and as a result, it is necessary to use silicone oil as a fixing device, and furthermore, the odor of the chain transfer agent becomes a problem.
[0007]
In order to solve the problem of the odor of the chain transfer agent, various methods (see Patent Documents 1, 2, and 34) have been proposed. These chain transfer agents have an effect of reducing the odor in addition to the function of adjusting the molecular weight of the resin. On the other hand, since there is only a low molecular weight effect by the chain transfer agent, there is a problem that the viscosity of the toner is reduced due to the reduction of the molecular weight of the resin, so that the offset property is deteriorated.
[0008]
[Patent Document 1]
JP-A-2002-72563
[0009]
[Patent Document 2]
JP-A-2002-91067
[0010]
[Patent Document 3]
JP-A-2002-91070
[0011]
[Patent Document 4]
JP-A-2002-123038
[0012]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic latent image formed by a polymerization method, which suppresses the generation of odor at the time of heat fixing, does not cause an odor problem, and has excellent fixability, and has a small particle size electrostatic latent image. An object of the present invention is to provide an image developing toner and an image forming method using the toner.
[0013]
[Means for Solving the Problems]
The above object of the present invention has been achieved by the following configurations.
[0014]
1. A toner comprising at least a resin and a colorant, wherein the resin is obtained by polymerizing a radically polymerizable monomer in the presence of a polyvalent chain transfer agent.
[0015]
2. In a toner comprising at least a resin and a colorant, the toner is obtained by fusing resin particles and colorant particles obtained by polymerizing a radical polymerizable monomer in the presence of a polyvalent chain transfer agent in an aqueous medium. A toner characterized in that:
[0016]
3. In a toner comprising at least a resin and a colorant, the toner is obtained by suspending a polymerization composition comprising a colorant, a radical polymerizable monomer, and a polyvalent chain transfer agent in an aqueous medium, and subjecting the polymer to suspension polymerization. Toner.
[0017]
4. 4. The toner according to any one of items 1 to 3, wherein the polyvalent chain transfer agent is a polyvalent ester mercapto compound.
[0018]
5. An image forming method using a contact-type fixing method, wherein the toner according to any one of the above items 1 to 4 is used.
[0019]
The present invention will be described in more detail. The present inventors have studied the resin design in detail in order to achieve the object of the present invention. As a result, it has been found that the subject of the present invention can be solved by a technique capable of forming a low molecular weight component and simultaneously forming a crosslinked structure.
[0020]
That is, although it is not clear about this effect, the use of a polyvalent chain transfer agent makes it possible to reduce the molecular weight and simultaneously form a crosslinked structure, thereby lowering the melt viscosity of the resin itself and It is estimated that the elastic modulus can be increased, the adhesiveness to paper can be improved, and the offset property can be improved.
[0021]
Specific examples of the polyvalent chain transfer agent of the present invention are shown below, but the present invention is not limited thereto.
(1) Neopentyl glycol bis (3-mercaptopropionate)
(2) Ethylene glycol bis (3-mercaptopropionate)
(3) Hexane glycol bis (3-mercaptopropionate)
(4) cyclohexane dimethanol bis (3-mercaptopropionate)
(5) Neopentyl glycol bis (8-mercaptocaprylate)
(6) Ethylene glycol bis (8-mercaptocaprylate)
(7) Hexane glycol bis (8-mercaptocaprylate)
(8) cyclohexane dimethanol bis (8-mercaptocaprylate)
(9) Neopentyl glycol bis (12-mercaptolaurate)
(10) Ethylene glycol bis (12-mercaptolaurate)
(11) Hexane glycol bis (12-mercaptolaurate)
(12) Cyclohexane dimethanol bis (12-mercaptolaurate)
(13) Trimethylolpropane tris (3-mercaptopropionate)
(14) Trimethylolpropane tris (8-mercaptocaprylate)
(15) Trimethylolpropane tris (12-mercaptolaurate)
(16) Pentaerythritol tetrakis (3-mercaptopropionate)
(17) Pentaerythritol tetrakis (8-mercaptocaprylate)
(18) Pentaerythritol tetrakis (12-mercaptolaurate)
As the polyvalent mercapto compound, a compound having an ester bond is preferable because of high solubility in a resin.
[0022]
The amount used depends on the design of the resin, but is preferably 0.1 to 5% by mass based on the radical polymerizable monomer. If the amount is less than 0.1% by mass, it is difficult to exert its effect, and it becomes difficult to reduce the molecular weight of the resin. When the amount exceeds 5% by mass, the effect of chain transfer is sufficiently exhibited, but an excessive amount of the polyvalent chain transfer agent is present. It is.
[0023]
As the radical polymerizable monomer, it is preferable to include at least one of the following radical polymerizable monomers having an acidic group or a radical polymerizable monomer having a basic group.
[0024]
Radical polymerizable monomer
The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Further, one kind or a combination of two or more kinds can be used so as to satisfy required characteristics.
[0025]
Specifically, aromatic vinyl monomers, (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers And halogenated olefin monomers.
[0026]
Examples of the aromatic vinyl monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, and p-methylstyrene. -N-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2, Styrene-based monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene, and derivatives thereof.
[0027]
(Meth) acrylic ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid Examples thereof include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.
[0028]
Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl benzoate.
[0029]
Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.
[0030]
Examples of the monoolefin-based monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene, and the like.
[0031]
Examples of the diolefin-based monomer include butadiene, isoprene, and chloroprene.
[0032]
Examples of the halogenated olefin-based monomer include vinyl chloride, vinylidene chloride, and vinyl bromide.
[0033]
Crosslinking agent
As a crosslinking agent, a radical polymerizable crosslinking agent may be added to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinylether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.
[0034]
Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group
Examples of the radical polymerizable monomer having an acidic group or the radical polymerizable monomer having a basic group include a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, a primary amine, and a secondary amine. Amine compounds such as amines, tertiary amines and quaternary ammonium salts can be used.
[0035]
As the radical polymerizable monomer having an acidic group, as a carboxylic acid group-containing monomer, acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monoester Octyl ester and the like.
[0036]
Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate, and the like.
[0037]
These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.
[0038]
Examples of the radical polymerizable monomer having a basic group include amine compounds, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds. 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide Vinyl pyridine, vinyl pyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diali Ammonium chloride, N, N-diallyl-ethyl ammonium chloride, and the like.
[0039]
As the radical polymerizable monomer used in the present invention, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is used in an amount of 0.1 to 15% by mass of the whole monomer. The radical polymerizable crosslinking agent is preferably used in an amount of 0.1 to 10% by mass based on the total amount of the radical polymerizable monomer, though it depends on its properties.
[0040]
Polymerization initiator
In the emulsion association type, since the resin particles are prepared by an emulsion polymerization method, the radical polymerization initiator can be appropriately used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salts, etc.), peroxides And the like.
[0041]
Further, the radical polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. By using the redox initiator, the polymerization activity is increased, the polymerization temperature is lowered, and the polymerization time can be further reduced.
[0042]
As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, by using a polymerization initiator started at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid), polymerization can be performed at room temperature or higher.
[0043]
In the case of the suspension polymerization method, an oil-soluble polymerization initiator can be used. For example, azoisobutyronitrile, azoisovaleronitrile, lauryl peroxide, and benzoyl peroxide can be given.
[0044]
Surfactant
In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is necessary to disperse oil droplets in an aqueous medium using a surfactant. The surfactant that can be used at this time is not particularly limited, but the following ionic surfactants can be mentioned as preferred examples.
[0045]
Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6). Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, sodium 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonate), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, sodium stearate) Beam, calcium oleate and the like).
[0046]
Further, a nonionic surfactant can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, esters of higher fatty acids and polypropylene oxide, sorbitan esters Etc. can be given.
[0047]
In the present invention, these are mainly used as emulsifiers at the time of emulsion polymerization, but they may be used for other steps or purposes.
[0048]
Colorant
Examples of the coloring agent include inorganic pigments, organic pigments, and dyes.
[0049]
Conventionally known inorganic pigments can be used. Specific examples of the inorganic pigment are shown below.
[0050]
As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.
[0051]
These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the pigment to be added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.
[0052]
When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic properties, it is preferable to add 20 to 60% by mass to the toner.
[0053]
Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.
[0054]
Pigments for magenta or red include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.
[0055]
Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 185, C.I. I. Pigment yellow 155, C.I. I. Pigment Yellow 156, and the like.
[0056]
Examples of green or cyan pigments include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.
[0057]
Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc., and mixtures thereof can also be used.
[0058]
These organic pigments and dyes can be used alone or in combination as required. The amount of the pigment to be added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.
[0059]
The colorant can be used after surface modification. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.
[0060]
Manufacturing process
The toner of the present invention is prepared by a suspension polymerization method or emulsion polymerization of a monomer in a liquid to which an emulsion of a necessary additive is added to produce fine polymerized particles. Can be produced by a method of associating with the addition of a compound. A method of preparing by associating with a dispersion liquid such as a release agent and a colorant necessary for the composition of the toner at the time of association, and dispersing toner components such as a release agent and a colorant in a monomer. And then emulsion polymerization. Here, the association means that a plurality of resin particles and colorant particles are fused.
[0061]
The term “aqueous medium” used in the present invention means a medium containing at least 50% by mass of water. That is, various constituent materials such as a colorant and a releasing agent, if necessary, a charge control agent, and a polymerization initiator are added to the polymerizable monomer. Various constituent materials are dissolved or dispersed in the polymerizable monomer. The polymerizable monomer in which the various constituent materials are dissolved or dispersed is dispersed in an aqueous medium containing a dispersion stabilizer into oil droplets having a desired size as a toner by using a homomixer or a homogenizer. Thereafter, the stirring mechanism is moved to a reaction device, which is a stirring blade described below, and heated to cause the polymerization reaction to proceed. After completion of the reaction, the toner of the present invention is prepared by removing the dispersion stabilizer, filtering, washing and drying.
[0062]
Further, as a method of producing the toner of the present invention, a method of preparing by associating or fusing resin particles in an aqueous medium can also be mentioned. Although this method is not particularly limited, for example, the methods described in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904 can be used. That is, a method of associating a plurality of resin particles and dispersed particles of a constituent material such as a colorant, or a method of associating a plurality of fine particles composed of a resin and a colorant, particularly, after dispersing these in water using an emulsifier, the At the same time as adding the above flocculant and salting out, the formed polymer itself is heated and fused at a temperature equal to or higher than the glass transition temperature to gradually grow the particle size while forming fused particles, and the desired particle size is obtained. At this point, a large amount of water was added to stop the growth of the particle size, and the surface of the particles was smoothed with heating and stirring to control the shape. The toner of the invention can be formed. Here, an organic solvent infinitely soluble in water may be added together with the coagulant.
[0063]
Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. Further, a surfactant generally used as a surfactant such as polyvinyl alcohol, gelatin, methyl cellulose, sodium dodecylbenzenesulfonate, an ethylene oxide adduct, and higher alcohol sodium sulfate can be used as a dispersion stabilizer.
[0064]
As the resin excellent in the present invention, a resin having a glass transition point of 20 to 90 ° C is preferable, and a resin having a softening point of 80 to 220 ° C is preferable. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Further, these resins have a number average molecular weight (Mn) of 1,000 to 100,000 and a mass average molecular weight (Mw) of 2,000 to 1,000,000 as measured by gel permeation chromatography. Is preferred. Further, the molecular weight distribution is preferably such that Mw / Mn is 1.5 to 100, particularly 1.8 to 70.
[0065]
The flocculant used is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, a salt of an alkali metal such as sodium, potassium or lithium; as a divalent metal, for example, a salt of an alkaline earth metal such as calcium or magnesium, or a divalent metal such as manganese or copper And salts of trivalent metals such as iron and aluminum. Specific examples of the salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Can be mentioned. These may be used in combination.
[0066]
It is preferable that these coagulants are added at a critical coagulation concentration or higher. The critical aggregation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which aggregation occurs when a coagulant is added. This critical aggregation concentration varies greatly depending on the emulsified component and the dispersant itself. For example, it is described in Seizo Okamura et al., “Polymer Chemistry # 17, 601 (1960), edited by The Society of Polymer Science, Japan” and the like, and a detailed critical aggregation concentration can be obtained. As another method, a desired salt is added to the target particle dispersion at a different concentration, and the ζ (zeta) potential of the dispersion is measured. The salt concentration at which this value changes is defined as the critical aggregation concentration. You can also ask.
[0067]
The amount of the coagulant of the present invention may be at least the critical coagulation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical coagulation concentration.
[0068]
The infinitely soluble solvent means a solvent that is infinitely soluble in water, and in the present invention, a solvent that does not dissolve the formed resin is selected. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropanol are preferred.
[0069]
The addition amount of the infinitely soluble solvent is preferably 1 to 100% by volume based on the polymer-containing dispersion to which the coagulant has been added.
[0070]
In addition, in order to make the shape uniform, it is preferable to prepare a colored particle, and after the filtration, it is preferable to fluidly dry a slurry in which 10% by mass or more of water is present with respect to the particle. Having a polar group is preferred. The reason for this is considered to be that it is particularly easy to achieve a uniform shape because the existing water exerts an effect of slightly swelling the polymer having the polar group.
[0071]
Although the toner of the present invention contains at least a resin and a colorant, it may contain a releasing agent or a charge control agent as a fixability improving agent, if necessary. Further, an external additive composed of inorganic fine particles, organic fine particles, and the like may be added to the toner particles containing the resin and the colorant as main components.
[0072]
As a method of adding a colorant, a method of adding a polymer particle prepared by an emulsion polymerization method at the stage of aggregating by adding an aggregating agent and coloring the polymer, or a process of polymerizing a monomer at the colorant And polymerizing it to obtain colored particles. When the colorant is added at the stage of preparing the polymer, it is preferable to use the colorant after treating the surface with a coupling agent or the like so as not to inhibit the radical polymerizability.
[0073]
The structure and composition of the release agent itself that can be used in the toner of the present invention are not particularly limited. Low molecular weight polyolefin wax such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used. Among them, those preferably used are ester waxes represented by the following general formula.
[0074]
R₁-(OCO-R₂)_n
In the formula, n represents an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, particularly preferably 4.₁, R₂Represents a hydrocarbon group which may have a substituent. Note that R₁Has 1 to 40 carbon atoms, preferably 1 to 20, more preferably 2 to 5,₂Has 1 to 40 carbon atoms, preferably 16 to 30, and more preferably 18 to 26 carbon atoms. Specific examples of preferred ester waxes are shown below.
(1) CH₃− (CH₂)₁₂-COO- (CH₂)₁₇-CH₃
(2) CH₃− (CH₂)₁₈-COO- (CH₂)₁₇-CH₃
(3) CH₃− (CH₂)₂₀-COO- (CH₂)₁₇-CH₃
(4) CH₃− (CH₂)₁₄-COO- (CH₂)₁₉-CH₃
(5) CH₃− (CH₂)₂₀-COO- (CH₂)₆-O-CO- (CH₂)₂₀-CH₃
[0075]
Embedded image

[0076]
Embedded image

[0077]
The addition amount of the above compound is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass based on the whole toner.
[0078]
Similarly, various known charge control agents, which can be dispersed in water, can be used. Specific examples include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid or a metal complex thereof.
[0079]
The particles of the charge control agent and the fixability improving agent preferably have a number average primary particle diameter of about 10 to 500 nm in a dispersed state.
[0080]
In the case of a suspension polymerization method toner in which a toner component such as a colorant is dispersed or dissolved in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized to obtain a toner, a reaction vessel for performing a polymerization reaction is used. By controlling the flow of the medium in the above, the shape of the toner particles can be controlled. That is, when many toner particles having a shape factor of 1.2 or more are to be formed, the flow of the medium in the reaction vessel is made turbulent, and the polymerization proceeds to be present in the aqueous medium in a suspended state. When the oil droplets are gradually polymerized, the oil droplets become soft particles.When the oil droplets collide, the particles collide to promote coalescence of the particles, resulting in particles with irregular shapes. . When spherical toner particles having a shape factor smaller than 1.2 are formed, spherical particles can be obtained by using a medium flow in the reaction vessel as a laminar flow to avoid collision of the particles. By this method, the distribution of the toner shape can be controlled within the scope of the present invention.
[0081]
In the suspension polymerization method, by using a specific stirring blade, a turbulent flow can be formed, and the shape can be easily controlled. The reason for this is not clear, but in the case where the structure of the stirring blade attached to the rotating shaft 3 as shown in FIG. The flow of the medium formed therein is only the flow moving along the wall surface from the lower part to the upper part of the stirring tank. Therefore, conventionally, a turbulent flow is generally formed by arranging a turbulent flow forming member (a baffle plate) 9 for enabling the agitation on the wall surface of the agitation tank, and the efficiency of the agitation is increased. ing. However, in such an apparatus configuration, although a turbulent flow is partially formed, the presence of the turbulent flow acts in a direction in which the fluid flow stagnates. Sometimes you cannot control it.
[0082]
A stirring tank provided with a stirring blade that can be preferably used will be described with reference to the drawings. FIG. 2 is an example of a perspective view of a stirring tank provided with two-stage stirring blades (however, as described later, it is better to change the shape of the stirring blades and to have a turbulence forming member). A rotating shaft 3 is suspended from the center of a vertical cylindrical stirring tank 2 having a heat exchange jacket 1 attached to the outer periphery of the stirring tank. There is a lower stirring blade 4 disposed therein and a stirring blade 5 disposed higher in the stage. The upper-stage stirring blade 5 is disposed at an intersection angle α that precedes the rotation direction with respect to the lower-stage stirring blade 4. In the present invention, the intersection angle α is less than 90 degrees (°). The lower limit of the intersection angle is not particularly limited, but may be about 5 ° or more, preferably 10 ° or more. FIG. 3 shows this in a top sectional view. If there are three or more stages, the intersection angle α between the adjacent stirring blades may be less than 90 degrees.
[0083]
With this configuration, the medium is first stirred by the stirring blades disposed in the upper stage, and a flow to the lower side is formed. Then, by the stirring blades arranged in the lower stage, the flow formed by the upper stirring blades is further accelerated downward, and a downward flow is separately formed by the stirring blades themselves, and the flow is accelerated as a whole. It is presumed to progress. As a result, it is presumed that a basin having a large shear stress formed as a turbulent flow is formed, so that the shape of the toner can be controlled.
[0084]
In FIG. 2, the arrow indicates the rotation direction, 7 indicates the upper material inlet, and 8 indicates the lower material inlet.
[0085]
Here, the shape of the stirring blade is not particularly limited, but may be a square plate, a notch in a part of the blade, a hole having one or more middle holes in the center, a so-called slit, and the like. Can be used.
[0086]
These examples are described in FIG. In the figure, (a) is a stirring blade without a hole, (b) is a large hole 6 in the center, (c) is a hole with a horizontal hole 6, and (d) is vertically long. There is a middle hole 6. Also, these may be different from each other in the middle hole portion 6 in the upper stage and the lower stage, or may be the same.
[0087]
FIGS. 5 to 9 show examples of preferable configurations that can be used as the configuration of the stirring blade. FIG. 5 shows a configuration having a projection at the end of the stirring blade and / or a bent portion at the end, FIG. 6 shows a configuration having a slit at the lower stage of the stirring blade and bending and a projection at the end, and FIG. 8 has a projection and a bend at the end, FIG. 8 shows a configuration having a slit in the upper stirring blade and a bend and a projection at the end of the lower stirring blade, and FIG. 9 shows a configuration having three stages of the stirring blade. Are respectively shown. The angle of the bent portion at the end of the stirring blade is preferably about 5 to 45 °.
[0088]
The agitating blade having the bent portion (4 "or 5") and the projection (4 'or 5') upward or downward effectively generates turbulence.
[0089]
The gap between the upper and lower stirring blades having the above configuration is not particularly limited, but it is preferable that at least a gap is provided between the stirring blades. Although the reason is not clear, it is considered that the flow of the medium is formed through the gap, so that the stirring efficiency is improved. However, the gap has a width of 0.5 to 50%, preferably 1 to 30% with respect to the liquid level in the stationary state.
[0090]
Furthermore, although the size of the stirring blade is not particularly limited, the sum of the heights of all the stirring blades is 50% to 100%, preferably 60% to 95% of the liquid level height in a stationary state. is there.
[0091]
FIG. 7 shows an example of a stirring blade and a stirring tank used when a laminar flow is formed in the suspension polymerization method. It is characterized in that no obstacle such as a baffle plate which forms a turbulent flow is provided in the stirring tank. Regarding the configuration of the stirring blade, similarly to the stirring blade used for forming the turbulent flow described above, the upper stirring blade is arranged with the intersection angle α leading in the rotation direction with respect to the lower stirring blade. It is preferable to provide a multi-stage configuration.
[0092]
The shape of the stirring blade is not particularly limited as long as it does not form a turbulent flow. However, a shape formed by a continuous surface such as a rectangular plate-like shape in FIG. May be.
[0093]
On the other hand, in a polymerization method toner in which resin particles are associated or fused in an aqueous medium, by controlling the flow and temperature distribution of the medium in the reaction vessel at the fusion step, and further in the shape control step after fusion. The shape distribution and shape of the entire toner can be arbitrarily changed by controlling the heating temperature, the number of rotations for stirring, and the time.
[0094]
That is, in a polymerization toner in which resin particles are associated or fused, the flow in the reactor is made laminar, and a stirring blade and a stirring tank capable of making the internal temperature distribution uniform are used. By controlling the temperature, the number of revolutions, and the time in the shape control step, it is possible to form a toner having a shape factor and a uniform shape distribution according to the present invention. The reason for this is that when fusion is performed in a place where a laminar flow is formed, strong stress is not applied to the particles that are undergoing aggregation and fusion (association or aggregated particles) and the flow is accelerated in a laminar flow. It is presumed that as a result of the uniform temperature distribution in the stirring tank, the shape distribution of the fused particles becomes uniform. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.
[0095]
As the stirring blade and the stirring tank used for the polymerization method toner for associating or fusing the resin particles, those similar to the case of forming a laminar flow in the above-mentioned suspension polymerization method can be used, for example, those shown in FIG. Can be used. It is characterized in that no obstacle such as a baffle plate which forms a turbulent flow is provided in the stirring tank. Regarding the configuration of the stirring blade, similarly to the stirring blade used in the above-mentioned suspension polymerization method, the upper stirring blade is disposed with the intersection angle α preceding the lower stirring blade in the rotation direction. In addition, a multi-stage configuration is preferable.
[0096]
The shape of the stirring blade may be the same as that in the case of forming a laminar flow in the above-mentioned suspension polymerization method, and is not particularly limited as long as it does not form a turbulent flow. Those formed by continuous surfaces such as plate-like ones are preferable, and may have a curved surface.
[0097]
The shape of the toner obtained by fusing has an average value (average circularity) of a shape factor represented by the following equation of 0.930 to 0.980, preferably 0.940 to 0.975. preferable.
[0098]
Shape factor = (circumferential length obtained from equivalent circle diameter) / (perimeter of particle projected image)
The shape factor distribution is preferably sharp, the standard deviation of the circularity is preferably 0.10 or less, and the CV value calculated by the following equation is preferably less than 20%, and more preferably less than 10%.
[0099]
CV value = {(standard deviation of circularity) / (average circularity)} × 100
By setting the average circularity to 0.930 to 0.980, the shape of the toner can be made somewhat irregular, the heat transfer can be made more efficient, and the fixability can be further improved. it can. That is, the fixing property can be improved by setting the average circularity to 0.980 or less. Further, by setting the average circularity to 0.930 or more, the degree of irregularity of the particles can be suppressed, and the friability of the particles due to stress during use for a long period can be suppressed.
[0100]
Further, it is preferable that the distribution of the shape factor is sharp, and the standard deviation of the circularity is 0.10 or less, so that the toner can have a uniform shape, and the difference in fixing performance between the toners can be reduced. Therefore, the effect of preventing the fixing device from being contaminated by improving the fixing rate and reducing the offset property is further exhibited. When the CV value is also less than 20%, a sharp shape distribution can be similarly obtained, and the effect of improving the fixing property can be more remarkably exhibited.
[0101]
The method of measuring the shape factor is not limited. For example, a photograph in which toner particles are magnified 500 times with an electron microscope is taken, and the circularity is measured for 500 toners using an image analyzer. Then, by calculating the arithmetic average value, the average circularity can be calculated. In addition, as a simple measurement method, it can be measured by FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.).
[0102]
In order to control the shape, a proper process end time may be determined while monitoring characteristics of toner particles (colored particles) whose shape is being controlled in a process such as association.
[0103]
Monitoring means that a measuring device is incorporated in-line and process conditions are controlled based on the measurement result. That is, for example, in the case of a polymerization toner formed by incorporating measurement of shape and the like in-line and associating or fusing resin particles in an aqueous medium, the shape and particle size are sequentially sampled in a process such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained.
[0104]
Although the monitoring method is not particularly limited, a flow-type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid through. That is, a pump or the like is used from the reaction field to constantly monitor and measure the shape and the like, and stop the reaction when the desired shape and the like are obtained.
[0105]
The volume average particle diameter of the toner of the present invention is measured with a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Multisizer was used, and an interface for outputting the particle size distribution (manufactured by Nikkaki) and a personal computer were connected. The particle size distribution and the average particle size were calculated by measuring the volume distribution of toner having a size of 2 μm or more using an aperture having a size of 100 μm as the aperture used in the Coulter Multisizer.
[0106]
The toner of the present invention has a volume average particle diameter of 3 to 8 μm. In the case where toner particles are formed by a polymerization method, the particle size can be controlled by the concentration of the coagulant, the amount of the organic solvent added, the fusing time, and the composition of the polymer itself.
[0107]
When the volume average particle diameter is 3 to 8 μm, in the fixing step, toner particles having a large adhesive force that fly and adhere to the heating member to generate an offset are reduced, and the transfer efficiency is increased, and the halftone The image quality is improved, and the image quality of fine lines, dots, and the like is improved.
[0108]
Measurement condition
(1) Aperture: 100 μm
(2) Sample preparation method: An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml of an electrolytic solution [ISOTON® R-11 (manufactured by Coulter Scientific Japan)], and the mixture is stirred. Add. This system is prepared by subjecting the system to a dispersion treatment with an ultrasonic disperser for one minute.
[0109]
Further, in the toner of the present invention, more effects can be exhibited by adding and using fine particles such as inorganic fine particles and organic fine particles as an external additive. The reason for this is presumed that burying and desorption of the external additive can be effectively suppressed, so that the effect is remarkable.
[0110]
As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania, and alumina. Further, it is preferable that these inorganic fine particles have been subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent, or the like. The degree of the hydrophobic treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is to evaluate the wettability to methanol.
[0111]
In this method, 0.2 g of the inorganic fine particles to be measured is weighed and added to 50 ml of distilled water placed in a 200 ml beaker. Methanol is slowly dropped from a buret whose tip is immersed in the liquid until the entire inorganic fine particles are wet with slow stirring. When the amount of methanol required to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following equation.
[0112]
Hydrophobicity = {a / (a + 50)} × 100
The amount of the external additive added is 0.1 to 5.0% by mass, and preferably 0.5 to 4.0% by mass in the toner. Various external additives may be used in combination.
[0113]
The toner of the present invention may be, for example, a case where a magnetic substance is contained and used as a one-component magnetic toner, a case where it is used as a two-component developer by mixing with a so-called carrier, or a case where a non-magnetic toner is used alone. Any of these can be suitably used, but in the present invention, it is preferable to use it as a two-component developer used by mixing with a carrier.
[0114]
As the carrier constituting the two-component developer, as the magnetic particles, conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with aluminum and metals such as lead can be used. . Particularly, ferrite particles are preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution analyzer “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.
[0115]
The carrier is preferably a carrier further coated with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, for example, an olefin resin, a styrene resin, a styrene / acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin dispersion type carrier is not particularly limited, and a known resin can be used.For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, or the like can be used. it can.
[0116]
Next, FIG. 10 shows a cross-sectional configuration diagram of a color image forming apparatus as an example of the image forming apparatus according to the present invention. In FIG. 10, reference numeral 21 denotes a photosensitive drum serving as a latent image carrier, which is formed by applying an OPC photosensitive member (organic photosensitive member) on a drum base, is grounded, and is driven to rotate clockwise in the drawing. Reference numeral 22 denotes a scorotron charger, which is a charging means, and applies uniform charging of a high potential VH to the peripheral surface of the photoreceptor drum 21 by corona discharge using a grid maintained at a grid potential VG and a corona discharge wire. Prior to charging by the scorotron charger, in order to eliminate the history of the photoreceptor up to the previous print, exposure is performed by a PCL (pre-charging static eliminator) using a light emitting diode or the like to eliminate the charge on the peripheral surface of the photoreceptor. Good.
[0117]
After the photosensitive drum 21 is uniformly charged, the exposure unit 23 performs image exposure based on the image signal. The exposing means 23 is a means for performing main scanning by bending an optical path by a reflecting mirror 134 through a rotating polygon mirror 131, an fθ lens 132, and a cylindrical lens 133 using a laser diode (not shown) as a light emitting light source.
[0118]
Image exposure is performed in synchronization with the rotation (sub-scanning) of the photosensitive drum 21 to form a latent image. In this example, the character portion is exposed to form a reversal latent image such that the character portion has the lower potential VL.
[0119]
At the periphery of the photosensitive drum 21, developing units 24Y, 24M, each containing a two-component developer composed of a toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier, are provided. 24C and 24K are provided.
[0120]
The image forming process will be described. First, for example, yellow is developed as the first color. Usually, the developer is composed of a carrier having ferrite as a core and an insulating resin coated around the core, and a toner containing polyester as a main material and a pigment corresponding to a color, a charge control agent, silica, titanium oxide and the like. The developer is conveyed to the developing area by regulating the developer layer thickness to 100 to 600 μm on the developing sleeve by the layer forming means.
[0121]
The gap between the developing sleeve and the photosensitive drum 21 in the developing area is set to 0.2 to 1.0 mm which is larger than the thickness of the developer layer. During this time, the VAC AC bias and the VDC DC bias are applied in a superimposed manner. Since VDC, VH and the toner are charged in the same polarity, the toner triggered by VAC to separate from the carrier does not adhere to the VH portion having a higher potential than VDC, but adheres to the VL portion having a lower potential than VDC. Then, visualization (reversal development) is performed.
[0122]
After the visualization of the first color is completed, the process enters the magenta image forming process of the second color, and uniform charging is again performed by the scorotron charger, and a latent image based on the image data of the second color is formed by the exposure unit 23.
[0123]
Again, a portion of the photoconductor having the potential of VH over the entire peripheral surface of the photoconductor drum 21 where no image of the first color is formed, a latent image similar to that of the first color is formed and development is performed. In a portion where the image of the first color is developed again, the latent image of VM 'is formed by the light attached to the toner of the first color and the charge of the toner itself, and the development corresponding to the potential difference between VDC and VM'. Is performed. In the overlapping portion of the first color image and the second color image, if the development of the first color is performed by forming a VL latent image, the balance between the first color and the second color is lost, so that the exposure amount of the first color is reduced and VH> There may be a case where the intermediate potential VM satisfies VM> VL.
[0124]
For the third color cyan and the fourth color black, the same image forming process as that for the second color magenta is performed, and a visible image of four colors is formed on the peripheral surface of the photosensitive drum 21.
[0125]
On the other hand, one sheet of recording material (recording paper or the like) P conveyed from the paper supply cassette via a half-moon roller is temporarily stopped near a pair of registration rollers (paper supply roller) via a pair of feed rollers, and the timing of transfer is determined. When it is set, the sheet is fed to the transfer area by rotating the registration roller.
[0126]
In the transfer area, a transfer unit is pressed against the peripheral surface of the photosensitive drum 21 in synchronization with the transfer timing, and the fed recording material P is sandwiched to transfer the multicolor image at once.
[0127]
Next, the recording material P is neutralized by a separation unit, separated from the peripheral surface of the photoconductor drum 21 and conveyed to a fixing device (fixing unit) 40, where a heating roller (upper roller) 41 and a pressure roller (lower roller) 42. After the toner is fused by heating and pressurizing, the toner is discharged onto a discharge tray outside the apparatus via a discharge roller. The transfer unit is retracted from the peripheral surface of the photosensitive drum 21 after the recording material P has passed, and is ready for the formation of the next toner image.
[0128]
On the other hand, the photosensitive drum 21 from which the recording material P has been separated is subjected to static elimination by the static eliminator, and then the residual toner is removed and pressed by pressing the blade of the cleaning means 25, and is again eliminated by the PCL and charged by the scorotron charger. Then, the process of the next image formation is started. The blade moves immediately after the cleaning of the surface of the photoconductor and retreats from the peripheral surface of the photoconductor drum 21. The waste toner scraped into the cleaning unit 25 by the blade is discharged by a screw and then stored in a waste toner collecting container (not shown).
[0129]
As a suitable fixing method used in the present invention, a so-called contact heating method can be used. In particular, examples of the contact heating method include a heat and pressure fixing method, a hot roll fixing method, and a pressure contact heat fixing method in which fixing is performed by a rotating pressing member including a fixedly disposed heating element.
[0130]
In the heat roll fixing method, an upper roller having a heat source inside a metal cylinder composed of iron or aluminum or the like, whose surface is often coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxyvinyl ether copolymer, etc. And a lower roller made of silicone rubber or the like. A typical example of the heat source is one having a linear heater and heating the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing section, pressure is applied between the upper roller and the lower roller to deform the lower roller and form a so-called nip. The nip width is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is preferably from 40 mm / sec to 600 mm / sec. If the nip is narrow, heat cannot be uniformly applied to the toner, causing uneven fixing. On the other hand, if the nip width is wide, the melting of the resin is promoted, and a problem occurs in which the fixing offset becomes excessive.
[0131]
A fixing cleaning mechanism may be provided for use. As this method, there can be used a method in which silicone oil is supplied to a roller or a film after fixing, or a method in which cleaning is performed with a pad, roller, web, or the like impregnated with silicone oil.
[0132]
The fixing device may be provided with a cleaning mechanism. As a cleaning method, a method of supplying various silicone oils to the fixing film or a method of cleaning with a pad, a roller, a web or the like impregnated with various silicone oils is used.
[0133]
As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane and the like can be used. Further, a siloxane containing fluorine can also be suitably used.
[0134]
【Example】
(Latex production example 1)
A solution in which 7.08 g of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was previously dissolved in ion-exchanged water (2760 g) in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device. Is added. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, 72.0 g of Exemplified Compound (20) was added to a monomer composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid, and the mixture was heated to 80 ° C. and dissolved to prepare a monomer solution. The heated solution was mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle diameter. Subsequently, a solution in which 0.84 g of a polymerization initiator (potassium persulfate: KPS) was dissolved in 200 g of ion-exchanged water was added, and the mixture was heated and stirred at 80 ° C. for 3 hours to produce latex particles. Subsequently, a solution prepared by dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water was added. After 15 minutes, 383.6 g of styrene, 140.0 g of n-butyl acrylate, 36. A mixed solution of 4 g and 5.0 g of the polyvalent chain transfer agent (13) was added dropwise over 100 minutes. After completion of the dropwise addition, the mixture was heated and stirred for 60 minutes and then cooled to 40 ° C. to obtain latex particles. This latex particle is referred to as Latex 1.
[0135]
(Latex production example 2)
Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 8.0 g of (14) was used instead of the polyvalent chain transfer agent (13). This is designated as latex 2.
[0136]
(Latex Production Example 3)
Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 15.0 g of (16) was used instead of the polyvalent chain transfer agent (13). This is designated as latex 3.
[0137]
(Latex production example 4)
Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 2.0 g of (18) was used instead of the polyvalent chain transfer agent (13). This is designated as Latex 4.
[0138]
(Latex Preparation Example 5)
Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 5.0 g of (7) was used instead of the polyvalent chain transfer agent (13). This is designated as Latex 5.
[0139]
(Latex Preparation Example 6)
Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 5.0 g of t-dodecyl mercaptan was used instead of the polyvalent chain transfer agent (13). This is designated as latex 6.
[0140]
(Example of toner production)
Production of colored particles 1Bk
9.2 g of sodium n-dodecyl sulfate is dissolved in 160 ml of ion-exchanged water with stirring. To this liquid, 20 g of Regal 330R (carbon black manufactured by Cabot Corporation) was gradually added under stirring, and then dispersed using CLEARMIX. The particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, it was 112 nm in mass average diameter. This dispersion is referred to as “colorant dispersion 1”.
[0141]
1250 g of the above-mentioned "latex 1", 2000 ml of ion-exchanged water and "colorant dispersion liquid 1" are stirred in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. After adjusting to 30 ° C., a 5 mol / L aqueous sodium hydroxide solution was added to the solution to adjust the pH to 10.0. Next, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added at 30 ° C. for 10 minutes with stirring. Thereafter, after standing for 3 minutes, heating is started, and the temperature is increased to 90 ° C. in 6 minutes (heating rate = 10 ° C./min). In this state, the particle size is measured with a Coulter Counter TAII, and when the volume average particle size becomes 6.5 μm, an aqueous solution in which 115 g of sodium chloride is dissolved in 700 ml of ion-exchanged water is added to stop the particle growth and further continued. Then, the mixture is heated and stirred at a liquid temperature of 90 ° C. ± 2 ° C. for 6 hours to cause salting out / fusion. Thereafter, the mixture was cooled to 30 ° C. at 6 ° C./min, hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The formed colored particles were filtered, washed repeatedly with ion-exchanged water, and then dried with warm air at 40 ° C. to obtain colored particles. The colored particles obtained as described above are referred to as “colored particles 1Bk”.
[0142]
In addition, "colored particles 1Bk" to "colored particles 6C" shown in Table 1 were obtained in the same manner except that the other "latex 2" to "latex 6" were used and carbon black and a coloring agent shown below were changed. Was.
[0143]
Colored particles 1Y
C. instead of carbon black I. Pigment Yellow 185 was used to obtain colored particles in the same manner. This is referred to as “colored particle 1Y”.
[0144]
Colored particles 1M
C. instead of carbon black I. Pigment Red 122 was used, and colored particles were obtained in the same manner. This is referred to as “colored particles 1M”.
[0145]
Colored particles 1C
C. instead of carbon black I. Pigment Blue 15: 3 was used, and colored particles were obtained in the same manner. This is referred to as “colored particle 1C”.
[0146]
Hereinafter, the colored particle 2 group used the latex 2 and prepared the colored particles 1 (Bk / Y / M / C) to the colored particles 6 (Bk / Y / M / C) using up to the latex 6.
[0147]
(Coloring particle production example 7Bk): Example of suspension polymerization method
In a four-necked flask equipped with a high-speed stirrer (TK homomixer), 710 parts by mass of ion-exchanged water and 450 parts by mass of a 0.1 mol / L aqueous solution of trisodium phosphate were added, and the mixture was heated to 65 ° C. and rotated at 12,000 rpm. 68 parts by mass of a 1.0 mol / L calcium chloride aqueous solution was gradually added under the stirring conditions of above to prepare an aqueous dispersion medium containing a dispersion containing colloidal tricalcium phosphate. Next, 14 parts by mass of carbon black (Legal 330R) was added to 165 parts by mass of styrene monomer and 35 parts by mass of n-butyl acrylate, and 30 parts by mass of ester wax (19) was added to a dispersion liquid dispersed by a sand grinder. Dissolved. Next, 2 parts by mass of the polyvalent chain transfer agent (13) and 10 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator were added to the aqueous dispersion medium, and the rotation speed was increased. Under a stirring condition of 12000 rpm, the mixture was gradually added to disperse a monomer-containing solution in water. Next, a polymerization reaction was carried out for 10 hours under the stirring conditions of 65 ° C. and 200 rpm in a nitrogen stream using a reaction apparatus having a stirring blade configuration shown in FIG. At the end of the polymerization reaction, hydrochloric acid was added to remove tricalcium phosphate as a dispersion stabilizer, followed by filtration, washing and drying to prepare colored particles. This is referred to as “colored particles 7Bk”. In addition, by monitoring during the polymerization, controlling the liquid temperature, the number of rotations of the stirring, and the heating time, the variation coefficient of the shape and the shape coefficient is controlled, and further, by the submerged classification, the variation coefficient of the particle size and the particle size distribution. Was arbitrarily adjusted.
[0148]
(Coloring particle production example 8Bk): Example of suspension polymerization method
Colored particles were obtained in the same manner as in Colored Particle Production Example 7Bk, except that 3 parts by mass of (14) was used instead of the polyvalent chain transfer agent (13). This is referred to as colored particles 8Bk.
[0149]
(Coloring particle production example 9Bk): Example of suspension polymerization method
Colored particles were obtained in the same manner as in Colored Particle Production Example 7Bk except that 3 parts by mass of (16) was used instead of the polyvalent chain transfer agent (13). This is referred to as colored particles 9Bk.
[0150]
(Coloring particle production example 10Bk): Example of suspension polymerization method
Colored particles were obtained in the same manner as in Colored Particle Production Example 7Bk except that t-dodecylmercaptan was used instead of the polyvalent chain transfer agent (13). This is referred to as colored particles 10Bk.
[0151]
[Table 1]

[0152]
[Table 2]

[0153]
In Table 2, the circularity was measured using FPIA-1000 under the conditions of a sample analysis amount of 0.3 μl and a number of detected particles of 1500 to 5000. The colored particles 6Bk, 6Y, 6M, 6C and the colored particles 10Bk are comparative examples.
[0154]
Next, hydrophobic silica (number-average primary particle diameter = 12 nm) is applied to each of the “colored particles 1Bk / 1Y / 1M / 1C” to “colored particles 6Bk / 6Y / 6M / 6C” and “colored particles 7Bk” to “colored particles 10Bk”. , Hydrophobicity = 71) and 1% by weight of hydrophobic titanium oxide (number-average primary particle diameter = 20 nm, hydrophobicity = 63) and mixed with a Henschel mixer to obtain a toner. These are referred to as “toner 1Bk / 1Y / 1M / 1C (colored particle 1 group)” to “toner 6Bk / 6Y / 6M / 6C (colored particle 6 group)”, “toner 7Bk (colored particle 7)” to “toner 10Bk ( Colored particles 10) ".
[0155]
[Table 3]

[0156]
Note that there is no difference between the colored particles and the toner in physical properties such as the shape and the particle size.
[0157]
A ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm was mixed with each of the toners to prepare a developer having a toner concentration of 6%. These correspond to the toner, and are referred to as “developer 1Bk / 1Y / 1M / 1C (developer group 1)” to “developer 6Bk / 6Y / 6M / 6C (developer group 6)” and “developer 7Bk (developer Agent 7) to “Developer 10Bk (Developer 10)”.
[0158]
Using the developer prepared here, a real copying evaluation was carried out using the color copying machine shown in FIG. 10 while changing the configuration of the fixing device to the following configuration.
[0159]
As a fixing device, a pressure fixing type heat fixing device as shown in FIG. 11 was used.
The specific configuration is as follows.
[0160]
The surface has a coating layer (thickness: 120 μm) 12 of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), an inner diameter of 40 mm, and a total width of 310 mm. 0.0mm aluminum alloy pipe 11 as a heating roller (upper roller) 41, the surface of which is also made of sponge-like silicone rubber (Asker C hardness = 48: thickness 2mm) 17 and has an inner diameter of 40mm and a thickness of 2.0mm (Lower roller) 42 having the iron pipe 16 of FIG. The nip width was 5.8 mm. Using this fixing device, the printing linear velocity was set to 250 mm / sec.
[0161]
Note that a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used as a cleaning mechanism of the fixing device.
[0162]
The fixing temperature was controlled by the surface temperature of the upper roll, and was set to 175 ° C. The amount of silicone oil applied was 0.6 mg / A4.
(Characteristic evaluation)
The fixability was evaluated as an A4 halftone image (each having a relative reflection density of 1.0 when the image density was set to "0" on the paper) in which the Y / M / C / Bk was printed in a single color. ) Was printed, and the fixing rate was measured. The fixing rate is a value obtained by rubbing a fixed image with a 1 kg weight wrapped with a “sarashi cloth” and calculating the percentage change in image density before and after the rubbing.
[0163]
Fixing rate (%) = (image density after rubbing) / (image density before rubbing) × 100
The surface temperature of the heating roller was 170 ° C. as a center value.
[0164]
In a closed room with a floor size of 5m x 5m and a height of 2m, a full-color image with a pixel rate of 50% was continuously printed at a set temperature of 170 ° C for 1,000 sheets, and the presence or absence of odor was evaluated by sensory evaluation. Carried out. The presence or absence of odor was evaluated by using 10 evaluators and the number of persons who felt odor.
[0165]
Further, a printing test was performed on 100,000 sheets to evaluate the presence or absence of contamination from the fixing portion.
[0166]
[Table 4]

[0167]
Examples 1 to 8 in the present invention all show good characteristics, but Comparative Examples 1 and 2 out of the present invention have an odor, and it can be seen that there is contamination from the fixing portion after printing 100,000 sheets. .
[0168]
【The invention's effect】
According to the present invention, in a toner for developing an electrostatic latent image of a so-called polymerization method, the generation of odor at the time of heat fixing is suppressed, the odor problem does not occur, and the electrostatic latent image having a small particle size and excellent fixability is provided. A developing toner and an image forming method using the same can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view of an example of a stirring tank provided with a conventional stirring blade.
FIG. 2 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 3 is a top sectional view of FIG. 2;
FIG. 4 is a schematic view of a shape of a stirring blade.
FIG. 5 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 6 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 7 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 8 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 9 is a perspective view of an example of a stirring tank provided with stirring blades.
FIG. 10 is a cross-sectional configuration diagram of a color image forming apparatus according to the present invention.
FIG. 11 is a schematic view of a heat fixing device according to the present invention.
[Explanation of symbols]
1) Jacket for heat exchange
2 stirring tank
3 rotation axis
4 Lower stage impeller
5 Upper stage stirring blade
6 hole
7 Upper material input port
8 Lower material input port
9 Turbulence forming member
11 aluminum alloy pipe
Coating layer of 12-tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer
13 heater
16 iron pipe
17 spongy silicone rubber
21 Photoconductor drum
22 charging means
23 Exposure means
24Y, 24M, 24C, 24K developing means
25 Cleaning means
40 fixing device
41 heating roller
42 pressure roller
α intersection angle
P recording material

Claims (5)

A toner comprising at least a resin and a colorant, wherein the resin is obtained by polymerizing a radically polymerizable monomer in the presence of a polyvalent chain transfer agent. In a toner comprising at least a resin and a colorant, the toner is obtained by fusing resin particles and colorant particles obtained by polymerizing a radical polymerizable monomer in the presence of a polyvalent chain transfer agent in an aqueous medium. A toner characterized in that: In a toner comprising at least a resin and a colorant, the toner is obtained by suspending a polymerization composition comprising a colorant, a radical polymerizable monomer, and a polyvalent chain transfer agent in an aqueous medium, and subjecting the polymer to suspension polymerization. Toner. The toner according to any one of claims 1 to 3, wherein the polyvalent chain transfer agent is a polyvalent ester mercapto compound. An image forming method using a contact-type fixing method, comprising using the toner according to claim 1.

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