JP3637378B2 - Color toner for electrophotography - Google Patents

Description

（但し、式中、Ｒ³、Ｒ⁴およびＲ⁵は水素原子または炭素数１〜１０のアルキル基あるいはアリル基であるが、特に水素原子または炭素数１〜６のアルキル基あるいはアリル基が望ましい。ここでＲ³、Ｒ⁴およびＲ⁵は同時に同じであっても異なっていても良い。また、Ｍｅは亜鉛、ニッケル、コバルト、銅およびクロムから選ばれるいずれかの金属である。）
【００４４】
また、本化合物は、Ｃｌａｒｋ，Ｊ，Ｌ，Ｋａｏ，Ｈ（１９４８）Ｊ．Ａｍｅｒ．Ｃｈｅｍ．Ｓｏｃ．７０，２１５１に記載された方法によって容易に合成することができる。例えば、溶媒中に２モルのサリチル酸ナトリウム塩（サリチル酸誘導体のナトリウム塩を含む）と、１モルの塩化亜鉛とを添加し混合し、加温して撹拌することにより亜鉛塩として得ることができる。
この金属塩は白色を呈する結晶であり、トナーバインダー中に分散させた場合にも着色を示さないものである。金属塩が亜鉛塩以外のものについても、上記の方法に準じて製造することができる。
本化合物の配合量は結着樹脂１００重量部に対し、０．１〜１０重量部、好ましくは０．５〜５重量部程度である。
なお、本化合物の具体例としては、以下に示すもの等が挙げられる。
【００４５】
【化３】

【００４６】
【化４】

【００４７】
【化５】

【００４８】
【化６】

【００４９】
【化７】

【００５０】
【化８】

【００５１】
【化９】

【００５２】
【化１０】

【００５３】
本発明のカラートナーに用いられる結着樹脂は、カラートナーに必要な透明性、光沢性、定着性、帯電性等から選択される各種のタイプのものが使用されるが、特にポリエステル樹脂やポリオール樹脂が好ましい。
ポリエステル樹脂としては各種のタイプのものがあるが、以下のものがカラートナーに必要な特性を維持するために好ましい。
【００５４】
【化１１】

（式中Ｒ¹は炭素数２〜４のアルキレン基であり、ｘ、ｙは正の整数であり、その和の平均値は２〜１６である。）で示されるジオール成分と、２価以上の多価カルボン酸、その無水物およびその低級アルキルエステルからなる群から選ばれる下記一般式（ＩＩ）また（ＩＩＩ）
【００５５】
【化１２】

【００５６】
【化１３】

（式中Ｒ²、Ｒ³は炭素数４〜２０の飽和もしくは不飽和の炭化水素基である。）で示される２価カルボン酸、もしくはその無水物を含有する酸成分、もしくはトリメリット酸か、その無水物も含有する酸成分とを縮合重合して得られるポリエステル樹脂である。
【００５７】
また、前記一般式（ＩＩ）（ＩＩＩ）の残余成分としてフタル酸、イソフタル酸、テレフタル酸、マレイン酸、フマル酸、およびそれらの無水物およびそれらの低級アルキルエステル等の化合物が使用できる。
また、前記一般式（ＩＩ）又は（ＩＩＩ）で示される化合物として、ｎ−ドデセニルこはく酸、ｎ−ドデシルこはく酸、ｎ−ブチルこはく酸、イソ−ドデセニルこはく酸、イソ−オクチルこはく酸等のこはく酸誘導体が挙げられ、特にこれらのものを用いると、トナーとしての低温時の定着性が十分で、さらに光沢も向上する。
【００５８】
また、前記一般式（Ｉ）で示されるジオールの例としては、ポリオキシプロピレン（２，２）−２，２−ビス（４−ヒドロキシフェニル）プロパン、ポリオキシエステル（２）−２，２−ビス（４−ヒドロキシフェニル）プロパン、ポリオキシプロピレン（６）−２，２−ビス（４−ヒドロキシフェニル）プロパン、ポリオキシプロピレン（１６）−２，２−ビス（４−ヒドロキシフェニル）プロパン、等が挙げられる。
なお、ジオール成分に下記のような２官能以上のポリヒドロキシ化合物を、約５モル％以下使用することもできる。エチレングリコール、プロピレングリコール、グリセリン、ペンタエリスリトール、トリメチロールプロパン、水素添加ビスフェノールＡ、ソルビトール、またはそれらのエーテル化ポリヒドロキシル化合物等。
上記ポリエステル樹脂は、通常ポリオール成分と多価カルボン酸成分とを不活性ガス雰囲気中で１８０〜２５０℃の温度で縮重合することによって製造することができる。
【００５９】
また、ポリオール樹脂は、各種のタイプのものが使用できるが、本発明に用いられるものとして、以下のものが好ましい。即ち、特に、ポリオール樹脂として、▲１▼エポキシ樹脂と、▲２▼２価フェノールのアルキレンオキサイド付加物もしくはそのグリシジルエーテルと、▲３▼エポキシ基と反応する活性水素を分子中に１個有する化合物と、▲４▼エポキシ基と反応する活性水素を分子中に２個以上有する化合物を反応してなるポリオールを用いることが好ましい。さらにまた、▲１▼のエポキシ樹脂は、数平均分子量の相異する少なくとも２種以上のビスフェノールＡ型エポキシ樹脂であることが特に好ましい。このポリオール樹脂は良好な光沢、透明性を付与し、耐オフセット性に効果がある。
【００６０】
本発明に用いられるエポキシ樹脂は好ましくはビスフェノールＡやビスフェノールＦ等のビスフェノールとエピクロロヒドリンを結合して得られたものである。エポキシ樹脂は安定した定着特性や光沢を得るために、数平均分子量の相違する少なくとも２種以上のビスフェノールＡ型エポキシ樹脂で、低分子量成分の数平均分子量が３６０〜２０００であり、高分子量成分の数平均分子量が３０００〜１００００であることが好ましい。さらに低分子量成分が２０〜５０ｗｔ％、高分子量成分が５〜４０ｗｔ％であることが好ましい。低分子量成分が多すぎたり分子量３６０よりさらに低分子の場合は、光沢が出すぎたり、さらには保存性の悪化の可能性がある。また、高分子量成分が多すぎたり分子量１００００よりさらに高分子の場合には、光沢が不足したりする場合がある。
【００６１】
本発明で用いられる化合物として、２価フェノールのアルキレンオキサイド付加物としては以下のものが例示される。即ち、エチレンオキサイド、プロピレンオキサイド、ブチレンオキサイドおよびこれらの混合物とビスフェノールＡやビスフェノールＦ等のビスフェノールとの反応生成物が挙げられる。得られた付加物をエピクロロヒドリンやβ−メチルエピクロロヒドリンでグリシジル化して用いてもよい。特に下記一般式（ＩＶ）で表わされるビスフェノールＡのアルキレンオキサイド付加物のジグリシジルエーテルが好ましい。
【００６２】
【化１４】

【００６３】
また、２価フェノールのアルキレンオキサイド付加物もしくはそのグリシジルエーテルが、ポリオール樹脂に対して１０〜４０ｗｔ％含まれていることが好ましい。ここで量が少ないとカールが増すなどの不具合が生じ、またｎ＋ｍが７以上であったり量が多すぎると光沢が出すぎたり、さらには保存性の悪化の可能性がある。本発明で用いられるエポキシ基と反応する活性水素を分子中に一個有する化合物としては、１価フェノール類、２級アミン類、カルボン酸類がある。１価フェノール類としては以下のものが例示される。フェノール、クレゾール、イソプロピルフェノール、アミノフェノール、ノニルフェノール、ドデシルフェノール、キシレノール、ｐ−クミルフェノール等が挙げられる。２級アミン類としては、ジエチルアミン、ジプロピルアミン、ジブチルアミン、Ｎ−メチル（エチル）ピペラジン、ピペリジンなどが挙げられる。また、カルボン酸類としては、プロピオン酸、カプロン酸などが挙げられる。
【００６４】
本発明の主鎖にエポキシ樹脂部とアルキレンオキサイド部を有するポリオール樹脂を得るためには、種々の原材料の組合せが可能である。例えば、両末端グリシジル基のエポキシ樹脂と両末端グリシジル基の２価フェノールのアルキレンオキサイド付加物をジハライドやジイソシアネート、ジアミン、ジチオール、多価フェノール、ジカルボン酸と反応させることにより得ることができる。このうち、２価のフェノールを反応させるのが反応安定性の点で最も好ましい。また、ゲル化しない範囲で多価フェノール類や多価カルボン酸類を２価フェノールと併用するのも好ましい。ここで、多価フェノール類、多価カルボン酸類の量は全量に対し１５％以下、好ましくは１０％以下である。
【００６５】
本発明で用いられるエポキシ基と反応する活性水素を分子中に２個以上有する化合物としては、２価フェノール類、多価フェノール類、多価カルボン酸類が挙げられる。２価フェノールとしてはビスフェノールＡやビスフェノールＦ等のビスフェノールが挙げられる。また、多価フェノール類としてはオルソクレゾールノボラック類、フェノールノボラック類、トリス（４−ヒドロキシフェニル）メタン、１−［α−メチル−α−（４−ヒドロキシフェニル）エチル］ベンゼンが例示される。多価カルボン酸類としては、マロン酸、コハク酸、グルタル酸、アジピン酸、マレイン酸、フマル酸、フタル酸、テレフタル酸、トリメリット酸、無水トリメリット酸が例示される。
【００６６】
また、これらのポリエステル樹脂やポリオール樹脂は、高い架橋密度を持たせると、透明性や光沢度が得られにくくなるので、好ましくは、非架橋、もしくは弱い架橋（ＴＨＦ不溶分５ｗｔ％以下）とすることが好ましい。
また、これらのタイプの樹脂に限らず、必要に応じて公知のものを合わせて使用することもできる。
【００６７】
本発明に用いられる結着樹脂は、主として前記記載のものに加えて以下のものなどを添加することもできる。
例えば、ポリスチレン、ポリ−ｐ−クロロスチレン、ポリビニルトルエン等のスチレンおよびその置換体の単重合体；スチレン−ｐ−クロロスチレン共重合体、スチレン−プロピレン共重合体、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−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−アクリル酸オクチル共重合体、スチレン−メタクリル酸メチル共重合体、スチレン−メタクリル酸エチル共重合体、スチレン−メタクリル酸ブチル共重合体、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、スチレン−マレイン酸共重合体、スチレン−マレイン酸エステル共重合体等のスチレン系共重合体；ポリメチルメタクリレート、ポリブチルメタクリレート、ポリ塩化ビニル、ポリ酢酸ビニル、ポリウレタン、ポリアミド、エポキシ樹脂、ポリビニルブチラール、ポリアクリル酸樹脂、ロジン、変性ロジン、テルペン樹脂、フェノール樹脂等が挙げられる。
【００６８】
また特に、カラー画像に適切な光沢、透明性、定着性を得るために、トナーに用いる結着樹脂の１／２流出開始温度は１１０〜１３０℃であることが好ましい。１／２流出開始温度は以下のように測定できる。
すなわち、高架式フローテスタ（ＣＦＴ−５００：島津製作所製）を用い、ダイス細孔の径１ｍｍ、加圧２０ｋｇ／ｃｍ²、昇温速度６℃／ｍｉｎの条件で１ｃｍ³の試料を溶融流出させたときの流出開始点から流出終了点の高さの１／２に相当する温度を示す。
【００６９】
また更に、本発明のトナーに用いられる着色剤としては、イエロー、マゼンタ、シアン、ブラック各色のトナーを得ることが可能な染顔料が使用できる。
例えば、カーボンブラック、ランプブラック、群青、アニリンブルー、フタロシアニンブルー、フタロシアニングリーン、ハンザイエローＧ、ローダミン６Ｇ、レーキ、カルコオイルブルー、クロムイエロー、キナクリドン、ベンジジンイエロー、ローズベンガル、トリアリルメタン系染料等の染顔料など、従来公知のいかなる染顔料をも単独あるいは混合して使用し得る。
【００７０】
また、本発明のトナーに用いられる帯電制御剤は、前述のサリチル酸誘導体の金属塩を用いることが特に好ましいが、必要に応じてカラートナーの色調を損なうことのない透明もしくは白色の物質を添加して、トナーの帯電性を安定的に付与することができる。具体的には、有機ホウ素塩類、含フッ素四級アンモニウム塩類、カリックスアレン系化合物等が用いられるが、これらに限られるものではない。
また、外添加剤として、トナーの流動性を向上させる目的で、本発明に用いられる疎水性のシリカおよび酸化チタンの他に、アルミナ、更に必要に応じて脂肪酸金属塩類やポリフッ化ビニリデン等を添加しても良い。
【００７１】
【実施例】
以下に本発明を実施例により詳細に説明するが、本発明はこれらに限定されるものではない。
また、定着に関する特性測定は以下のとおりに行なった。
▲１▼オフセット未発生温度範囲
リコー製カラー複写機プリテール５５０を用いて、転写紙（リコー製タイプ６０００−７０Ｗ）に、イエロー、マゼンタ、シアン、ブラックの単色および中間色として、レッド、ブルー、グリーンから成るべタ画像を単色で、１．０±０．１ｍｇ／ｃｍ²のトナーが現像されるように調整を行ない、定着ユニットを改造し、定着ローラーの温度が可変となるように調整を行なって、オフセットの発生しない濃度を測定した。なお、定着ローラーには、オイルを塗布しない条件で評価を行なった。
【００７２】
▲２▼光沢度
上記単色画像サンプルにおいて、定着ローラー表面温度が１６０℃のときのサンプルの光沢度を、日本電色工業株式会社製のグロスメーターにより、入射角度６０°により計測した。この光沢度は、値の高い程、光沢感が出る。フルカラーのコピー画像としては、適度な光沢が好まれ、１０〜４０％程度が好ましい。
【００７３】
▲３▼へイズ度
上記単色画像サンプルを、転写紙としてリコー製のＯＨＰシート（タイプＰＰＣ−ＤＸ）を用い、定着ローラー表面温度が１６０℃のときのサンプルのへイズ度を、スガ試験機株式会社製の直読へイズ度コンピューターＨＧＭ−２ＤＰ型により測定した。
このへイズ度は、曇り度とも言われ、トナーの透明性を示す尺度として測定され、値の低いほど透明性が高く、ＯＨＰシートを用いた場合の発色性が良好なものとなる。また、良好な発色性を示すへイズ度の値は、３０％以下が好ましく、特に２０％以下である場合が好ましい。
【００７４】
また、一成分現像剤に関連する特性測定は以下の通りに行った。
▲４▼現像ローラー上トナー特性
（評価装置）
図１に示す現像装置（現像ローラー（２）は表層としてシリコーン樹脂を主成分としたもの、又は金属材質から成るものであり、本現像ローラーに当接するポリウレタン材質から成るトナー供給ローラー（３）、更に本現像ローラーに当接するウレタン材質から成るブレード（４）を、図１に示すように設定した）にトナーを供給する。図１において、（１）は潜像担持体（ベルト感光体）、（２）は現像ローラー、（２−１）は芯金、（２−２）は樹脂コート層、（３）はトナー供給部材、（４）は現像剤塗布ブレード、（５）はアジテーターおよび（６）は現像領域である。
【００７５】
▲４▼−１ 帯電量 ▲４▼−２ トナー付着量
出口側にフィルター層を具備したファラデーケージを介して、現像ローラー上のトナーを吸引し、ファラデーケージ内にトラップされたトナーの比電荷を測定する吸引法比電荷測定装置により、帯電量の測定を行なう。また、同時にトラップされたトナーの重量と、吸引された現像ローラーの面積との関係から、トナー付着量を算出する。
また、これらの特性の適正な値は、現像ローラーと感光体の線速（比）などで異なるが、一般には以下のとおりであり、特に多数枚のプリントによる現像ローラーの長期撹拌によっても安定していることが、現像されるトナー量が安定化する観点から好ましい。
帯電量 絶対値で１０〜２５（μｃ／ｇ）
付着量 ０．４〜１．２（ｍｇ／ｃｍ²）
【００７６】
▲４▼−３ トナー薄層性
現像ローラー上トナーの薄層性は目視による観察を行なった。また、現像ローラーの長期撹拌後に現像ユニットを分解し、トナーを除去後、現像ローラー上のトナーのフィルミング状態、現像剤塗布ブレードへのトナーの固着状態を目視により観察した。
【００７７】
実施例１（参考例）
・結着樹脂１
（ポリエステル樹脂、１／２流出開始温度：１２６℃） １００重量部
・帯電制御剤
（含フッ素４級アンモニウム塩化合物） ３重量部
・着色剤
＜イエロートナー用＞
ジスアゾ系イエロー顔料（C.I.Pigment Yellow１７） ５重量部
＜マゼンタトナー用＞
キナクリドン系マゼンタ顔料（C.I.Pigment Red１８４） ４重量部
＜シアントナー用＞
銅フタロシアニンブルー顔料（C.I.Pigment Blue１５） ２重量部
＜ブラックトナー用＞
カーボンブラック ５重量部
【００７８】
上記の材料を各色ごとにブレンダーで充分混合したのち、１００〜１１０℃に加熱した２本ロールによって溶融混練した。混練り物を自然放冷後、カッターミルで粗粉砕し、ジェット気流を用いた微粉砕機で粉砕後、風力分級装置を用いて各色の母体着色粒子を得た。なお、各色母体着色粒子の体積平均粒径は、以下のとおりであった。（なお、トナーの体積平均粒径は、コールターエレクトロニクス社製のコールターカウンターモデルＴＡ−ＩＩにより計測した。）
イエロー：８．１（μｍ）、マゼンタ：８．３（μｍ）
シアン ：８．４（μｍ）、ブラック：８．４（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００７９】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。なお、外添加剤の混合方法は表１中に示す。
【００８０】
さらに、本トナー５重量部とシリコーン樹脂でコーティングを行なった（平均樹脂膜厚み：０．３μｍ）平均粒径５０μｍのフェライトキャリア９５重量部をボールミルにて混合し、現像剤を得た。なお、現像剤の帯電量は−２２（μｃ／ｇ）であった。
【００８１】
得られたトナー及び現像剤を、リコー製ＰＲＥＴＥＲ６５０の改造機（定着ローラーに供給されているオイルを未使用とした）にセットし、３万枚のプリントを行なった。画像は鮮明で、３万枚プリントにおいても変化が少なかった。また、帯電量の変化も少なかった。評価結果の要約を表１に示す。
【００８２】
実施例２（参考例）
・結着樹脂
（ポリエステル樹脂、１／２流出開始温度：１２０℃） １００重量部
・帯電制御剤
（含フッ素４級アンモニウム塩化合物） ３重量部
・離型剤
（低分子量ポリプロピレン、融点：１１８℃） ３．５重量部
・着色剤
実施例１に同じ
【００８３】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：７．７（μｍ）、マゼンタ：７．５（μｍ）
シアン ：７．６（μｍ）、ブラック：７．４（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００８４】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを作成し、実施例１と同様に現像剤を作成し、同様の評価を行なった。３万枚のプリント後においても画像の変化が少なく、帯電量の変化も少なかった。更に、前記記載の方法により、オフセット未発生温度範囲、光沢度、ヘイズ度の評価を行なったところ、いずれも良好な結果を得た。
【００８５】
実施例３（参考例）
・結着樹脂
（ポリエステル樹脂、１／２流出開始温度：１２１℃） １００重量部
・帯電制御剤
（含フッ素４級アンモニウム塩化合物） ３重量部
・離型剤
（エステル系ワックス、融点：８５℃） ４重量部
・着色剤
実施例１に同じ
【００８６】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：８．５（μｍ）、マゼンタ：８．５（μｍ）
シアン ：８．８（μｍ）、ブラック：８．７（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００８７】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。得られたトナーを、リコー製マイリコピーＭ−５の改造機にセットし、現像ローラー上のトナー層の特性評価を行なった。なお、現像ローラー上のトナー薄層は均一で、３万枚プリント後においても変化がなく、帯電量とトナー付着量の変化も少なかった。更に、実施例２と同様の定着性の評価を行なったところ、実施例２と同様良好な結果を得た。評価結果の要約を表１に示す。
【００８８】
実施例４（参考例）
・結着樹脂
（ポリオール樹脂、１／２流出開始温度：１１６℃） １００重量部
・帯電制御剤
（含フッ素４級アンモニウム塩化合物） ４重量部
・離型剤
（低分子量ポリプロピレン、融点：１１０℃） ４重量部
・着色剤
実施例１に同じ
【００８９】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：６．７（μｍ）、マゼンタ：６．９（μｍ）
シアン ：６．８（μｍ）、ブラック：６．６（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００９０】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、実施例３と同様良好な結果を得た。更に、実施例２と同様の定着性の評価を行なったところ、実施例２と同様良好な結果を得た。評価結果の要約を表１に示す。
【００９１】
実施例５

【００９２】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：９．０（μｍ）、マゼンタ：９．２（μｍ）
シアン ：９．０（μｍ）、ブラック：９．１（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００９３】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、実施例３と同様良好な結果を得た。更に、実施例２と同様の定着性の評価を行なったところ、実施例２と同様良好な結果を得た。評価結果の要約を表１に示す。
【００９４】
実施例６

【００９５】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：９．４（μｍ）、マゼンタ：９．１（μｍ）
シアン ：９．３（μｍ）、ブラック：９．２（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００９６】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、実施例３と同様良好な結果を得た。更に、実施例２と同様の定着性の評価を行なったところ、実施例２と同様良好な結果を得た。評価結果の要約を表１に示す。
【００９７】
実施例７

【００９８】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：８．８（μｍ）、マゼンタ：９．２（μｍ）
シアン ：９．０（μｍ）、ブラック：９．２（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【００９９】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、実施例３と同様良好な結果を得た。更に、実施例２と同様の定着性の評価を行なったところ、実施例２と同様良好な結果を得た。評価結果の要約を表１に示す。
【０１００】
比較例１

【０１０１】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：７．５（μｍ）、マゼンタ：７．３（μｍ）
シアン ：７．６（μｍ）、ブラック：７．４（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【０１０２】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例１と同様にキャリアと混合を行ない、現像剤を得た。更に、実施例１と同様の評価を行なったところ、プリントを重ねるにつれて現像剤の帯電量が低下し、画像の地肌部に地汚れが発生した。評価結果の要約を表１に示す。
【０１０３】
比較例２

【０１０４】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：６．０（μｍ）、マゼンタ：６．１（μｍ）
シアン ：６．３（μｍ）、ブラック：５．９（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【０１０５】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、３万枚プリント後において帯電量が低下し、トナーの薄層が不均一化し、現像ローラーからトナー落ちが発生した。評価結果の要約を表１に示す。
【０１０６】
比較例３

【０１０７】
上記の材料を実施例１と同様に処理を行ない、以下の体積平均粒子径の母体着色粒子を得た。
イエロー：７．６（μｍ）、マゼンタ：７．７（μｍ）
シアン ：７．５（μｍ）、ブラック：７．８（μｍ）
なお、５μｍ以下の粒子の個数％と体積平均粒子径／個数平均粒子径を表１に示す。
【０１０８】
更に、母体着色粒子１００重量部に対して、外添加剤として、

をへンシェルミキサーにて混合を行ない、イエロー、マゼンタ、シアン、ブラックの各色のトナーを得た。更に、実施例３と同様の評価を行なったところ、初期より帯電量が低く、現像ローラーからトナー落ちが発生した。評価結果の要約を表１に示す。
【０１０９】
【表１−１】

【０１１０】
【表１−２】

【０１１１】
【表１−３】

【０１１２】
【表１−４】

【０１１３】
【表１−５】

【０１１４】
【表１−６】

【０１１５】
【発明の効果】
以上、詳細且つ具体的な説明より明らかなように、本発明のカラートナーは、少なくとも結着樹脂、着色剤、帯電制御剤を主成分とする母体トナーと、外添加剤からなるカラートナーにおいて、母体トナーの体積平均粒子径が６．５〜９．５μｍであり、５μｍ以下の粒子が２〜１５個数％、体積平均粒子径／個数平均粒子径＝１．１５〜１．２５であることによって、長期の使用においても安定した画像及び帯電量を維持できる。また、前記カラートナーの外添加剤として、（ｉ）１次粒子径０．０１〜０．０３μｍの疎水化処理されたシリカを、母体トナー１００重量部に対し０．２〜１．０重量部、（ ii ）１次粒子径０．０１〜０．０３μｍで比表面積６０〜１４０ｍ ² ／ｇの疎水化処理された酸化チタンを、母体トナー１００重量部に対し０．２〜０．８重量部、（ iii ）比表面積２０〜５０ｍ ² ／ｇ、嵩密度１００〜２５０ｇ／ｌの疎水化処理されたシリカを、母体トナー１００重量部に対し０．５〜２．０重量部、の３種類が添加されていることによって現像ローラー上でのトナーの薄層が均一化し、長期の撹拌においても、薄層の均一性を維持できる。また、少なくともトナー搬送部材及びトナー層厚規制部材を備え、トナー搬送部材とトナー層厚規制部材が当接している現像装置に、本発明のカラートナーを用いることによって、長期の使用においても安定した画像及び帯電量を維持できる。また、前記一成分現像用カラートナーを、少なくとも金属材質からなる現像ローラーと、この現像ローラーにゴム材質を表面に有する現像剤塗布ブレード当接させた現像装置に用いることにより、現像ローラ上のトナー特性を更に安定化できる。また、前記カラートナーに、エステル系又はオレフィン系のワックスを含有し、かつ、これらのワックスのトナー中での平均分散粒径が０．１〜３μｍであることによって、長期の使用においても安定した画像及び帯電量を維持できる。また、前記外添加剤の母体トナーへの混合被覆方法として、母体トナーと１次粒子径０．０１〜０．０３μｍの疎水化処理されたシリカと、１次粒子径０．０１〜０．０３μｍで比表面積６０〜１４０ｍ²／ｇの疎水化処理された酸化チタンを混合した後、比表面積２０〜５０ｍ²／ｇ、嵩密度１００〜２５０ｇ／ｌの疎水化処理されたシリカを添加して混合することにより、更に現像ローラ上のトナー特性を更に安定化維持できる。また、前記カラートナーの帯電制御剤として、サリチル酸誘導体の金属塩化合物を用いることにより、更に現像ローラ上のトナーの帯電特性を安定化維持できる。
【図面の簡単な説明】
【図１】本発明のトナーを使用するのに有用な現像装置の一例を示す現像ローラー部を中心とした模式断面図である。
【符号の説明】
１ 潜像担持体（ベルト感光体）
２ 現像ローラー
２−１ 芯金
２−２ 樹脂コート層
３ トナー供給部材
４ 現像剤塗布ブレード
５ アジテータ
６ 現像領域[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color toner for electrophotography.
[0002]
[Prior art]
In recent years, hard copy technology using an electrophotographic method has been rapidly developed from black and white to full color, and the full color market is particularly expanding. Color image formation by full-color electrophotography generally reproduces all colors using three color toners of three primary colors, yellow, magenta, and cyan, or four colors including black.
[0003]
In the general method, first, an electrostatic latent image is formed on a photoconductive layer by passing light from an original through a color separation light transmission filter having a complementary color and toner relationship. Next, the toner is held on a support through development and transfer processes. Next, the above-described steps are sequentially performed a plurality of times, and the toner is superposed on the same support while aligning the registration, and a final full-color image is obtained by fixing only once.
In color electrophotography in which development is performed multiple times and several toner images of different colors are required to be superimposed on the same support as the fixing process, the fixing characteristics that the color toner should have are extremely important. Is an element.
That is, the fixed color toner is required to suppress diffuse reflection by toner particles as much as possible and to have appropriate gloss and gloss.
In addition, the toner should be a color toner that has transparency that does not interfere with the toner layer of different color tone below the toner layer and has a wide color reproduction range.
[0004]
On the other hand, most fixing devices used for fixing color toners use a roller or the like using an excellent material having a good surface releasability, but most of them have oil applied to the surface of the roller or the like. However, the application of a large amount of oil to increase the releasability has problems such as oil stains on the transfer paper, an increase in cost, and a space for storing oil, resulting in an increase in the size of the fixing device.
[0005]
In general, the reason why oil is used for fixing color toner is as follows.
That is, the color toner needs to have higher heat meltability and lower viscosity to obtain gloss and transparency than the black toner for black and white printing during fixing heating. However, the toner using such a resin tends to decrease the cohesive force between molecules at the time of heat melting, so that the adhesion of the toner to the heat roller increases when passing through the fixing roller, and a high temperature offset phenomenon occurs. Therefore, in order to prevent this high temperature offset, it is common to apply oil to the fixing roller to reduce the adhesion of toner to the fixing roller.
[0006]
In addition, so-called oilless toner in which no oil is applied to the fixing roller has been tried, and it is generally proposed to disperse wax in the toner.
However, in the case of a color toner, as described above, it is necessary to sufficiently exude the wax from the low viscosity toner, and it is difficult to prevent the offset. In addition, in the case of a highly viscous toner such as black toner for black and white printing, since the intermolecular cohesion force at the time of heat melting of the toner is high, offset can be prevented by oozing out a small amount of wax. The toner is not melted and gloss and transparency are insufficient.
[0007]
On the other hand, regarding development, a non-magnetic one-component phenomenon has been proposed that is excellent in miniaturization and weight reduction and does not require the use of a carrier. In this developing system, the toner replenishment property to the developing roller and the toner retaining property of the developing roller are poor, so the toner is forcibly rubbed against the developing roller or the amount of toner on the developing roller is regulated by a blade. As a result, the toner tends to film on the developing roller, resulting in a problem that the life of the developing roller is shortened and the charge amount of the toner becomes unstable. This also prevents good development.
Therefore, in color toners for non-magnetic one-component development, in addition to the properties required for general color toners, the heat resistance of the binder resin used for the toner is often inferior, and the toner on the developing roller is often inferior. Filming is likely to occur. This phenomenon becomes more prominent when a release agent is included for the purpose of imparting releasability to the toner during fixing.
[0008]
In addition, in a two-component color developer composed of a color toner and a carrier, the use of the developer for a long time tends to cause a phenomenon that the toner is fused to the surface of the carrier, and the charge amount of the toner is reduced, which is favorable. Development is not performed. This phenomenon becomes more prominent when a release agent is contained.
[0009]
Japanese Patent No. 2763318 discloses 17 to 60% by number of 5 μm or less, 1 to 30% by number of 8 to 12.7 μm, 2% by volume or more of 12.7 μm or more, 4 to 10 μm of volume average particle diameter, and particles Although toners containing silica or titanium oxide have been described that define the particle size distribution, they have a wide particle size distribution and especially a high content of fine powder, so when used in a non-magnetic one-component development system, The toner filming is likely to occur.
[0010]
Japanese Patent Application Laid-Open No. 1-15859 discloses that a developing device having at least a toner conveying member and a layer thickness regulating member has a volume average particle diameter / number average particle diameter of 1.0 to 1.2 and a volume average particle diameter. JP-A-8-12475 discloses a method using a color toner having a diameter of 3 to 25 μm. Japanese Patent Publication No. 8-12475 discloses an etherified diphenol component, a divalent carboxylic acid substituted with a hydrocarbon group, or a derivative thereof. A color toner using a polyester resin having an apparent viscosity and a DSC endothermic peak, which is composed of a polycarboxylic acid or / and a polyol or a derivative component thereof higher than or equal to the number, is described in Japanese Patent Application Laid-Open No. 51-144625. Is a magenta obtained by adding a certain pigment to a resin mixture of a polyester resin having a softening point of 80 to 150 ° C. and a solid silicone varnish having a molecular weight of 500 to 2000. JP-A-5-158281 describes a toner having a haze value of 7 to 30% in a binder resin dispersion, and the binder resin is a weakly crosslinked resin. However, there is a problem that offset resistance is insufficient due to oilless fixing.
[0011]
JP-A-5-158282 discloses a phthalic acid-based divalent aromatic acid component, a trimellitic acid-based acid component, a succinic acid-based acid component, and an etherified diphenol. A color toner containing a polyester resin having an OH value of 10 to 20, Mw: 13000 to 20000, Mn: 5000 to 8000, Mw / Mn = 2 to 3.5 and a color image forming method are described. There is a problem that the offset resistance is insufficient for fixing, and JP-A-7-219274 discloses a pigment that has been heat-treated after mixing a polyolefin wax and a water-containing pigment paste into a resin solution for pigment dispersion. A color toner containing a dispersion resin and having a SP value difference between the binder resin and the pigment dispersion resin of 1.5 to 0.5 is described. Although those awaiting a suitable high dispersion of the binder resin, in order to impart oil-less resistance, than expected only effect of the polyolefin wax include a problem that is not sufficient.
[0012]
Japanese Patent Application Laid-Open No. 7-311479 describes that a fixing roller using toner described in Japanese Patent Application Laid-Open No. 7-219274 uses an elastic layer whose surface layer is coated with a fluororesin. The purpose is to increase the dispersion of the polyolefin wax in the binder resin, but it is not sufficient to expect only the effect of the polyolefin wax in order to impart oil-less properties. .
Japanese Patent Laid-Open No. 7-333903 describes a toner containing a polyester resin that does not contain THF (tetrahydrofuran) insoluble matter of Mn: 2500 to 3500 and Mw: 50,000 to 300,000. Fixing oil is required, and there is a problem that oillessness is insufficient.
[0013]
Japanese Patent Application Laid-Open No. 7-333904 discloses a polyester resin in which a polyhydric alcohol component is limited with a wax and THF insoluble content of 15 to 40%, and a difference in refractive index between the binder resin and the wax is limited. Although described, there is a problem that it is difficult to obtain high gloss because of a large amount of THF insoluble matter.
JP-A-8-50367 discloses that in a wax-containing toner, the molecular weight of the wax has a maximum value in each of 350 to 850 and 900 to 4000, Mn: 350 to 4000, Mw: 200 to 4000. However, there is a problem that sufficient oil-less property cannot be obtained only by limiting the properties of the wax.
[0014]
Japanese Patent Application Laid-Open No. 8-50368 describes a toner containing a wax in which an ester compound having the same total carbon number is contained in an ester wax in an amount of 50 to 95% by weight. However, the properties of the wax are limited. However, there is a problem that sufficient oil-less properties cannot be obtained.
JP-A-3-39971 does not contain toluene insolubles, has a molecular weight of 500 to 2,000 and peaks in the range of 10,000 to 100,000, Mw: 10,000 to 80,000, Mn: 1500 to 8000. Although a resin-containing color toner with Mw / Mn> 3 is described, there is a problem that sufficient oil-less property cannot be obtained.
JP-A-4-57062 discloses a flow tester melt viscosity of 10^FiveA resin-containing color toner having a softening temperature of Poise of 90 to 120 ° C., Mw: 15,000 to 50,000, Mn: 2000 to 10,000 and Mw / Mn = 5 to 15 is described. The problem is that it cannot be obtained.
[0015]
JP-A-5-53369 discloses a BET specific surface area of 1 to 150 m.²/ G, inorganic fine powder treated with a coupling agent having a saturated or unsaturated cyclic or acyclic organic group having 5 or more carbon atoms, and a BET specific surface area of 160 to 400 m²A toner having an inorganic fine powder having a hydrophobization degree of 30 or more per g is described, and Japanese Patent Application Laid-Open No. 8-15890 discloses toner particles having an average particle diameter of 4 to 9 μm, small particles (7 to 20 nm) and large particles. Although a one-component developer composed of an external additive having a diameter (20 to 80 nm) and having an external additive having a small particle diameter of 1 to 2% by weight is described, the charging characteristics of the toner become unstable on the developing roller, There is a problem that the toner may spill or scatter from the developing roller.
[0016]
JP-A-6-202374 describes a non-magnetic one-component toner in which inorganic fine particles having an average particle size of 30 nm or more and less than 100 nm are adhered, and JP-A-9-288369 discloses a BET ratio. Surface area is 20-50m²/ G, PH 6-8, toner containing silica fine particles having a hydrophobicity of 85% or more is described, and JP-A-9-297424 discloses a softening point (Sp) of 90-115 ° C., a glass transition point (Tg). The BET specific surface area is 70 m on the surface of the toner having a polyester resin with a relationship of Sp + 110 ≦ 4Tg ≦ Sp + 170.²Although a non-magnetic one-component toner having such fine particles has been described, there is a problem that the fluidity of the toner is insufficient and the toner replenishment property may be insufficient.
[0017]
[Problems to be solved by the invention]
An object of the present invention is to provide a color toner having good and stable developability even in long-term stirring.
[0018]
[Means for Solving the Problems]
  The above problem is that (1) “a base toner composed mainly of at least a binder resin, a colorant, and a charge control agent and a color toner composed of an external additive, and the volume average particle size of the base toner is 6. 5 to 9.5 μm, 2 to 15% by number of particles of 5 μm or less, and volume average particle diameter / number average particle diameter = 1.15 to 1.25As an external additive, (i) 0.2 to 1.0 parts by weight of hydrophobically treated silica having a primary particle size of 0.01 to 0.03 μm, based on 100 parts by weight of the base toner ( ii ) Primary particle size 0.01-0.03 μm and specific surface area 60-140 m ² / G hydrophobized titanium oxide of 0.2 to 0.8 parts by weight with respect to 100 parts by weight of the base toner ( iii ) Specific surface area 20-50m ² / G, silica having a bulk density of 100 to 250 g / l, and three types of silica, 0.5 to 2.0 parts by weight based on 100 parts by weight of the base toner, are added, and at least the toner A developing roller comprising a conveying member and a toner layer thickness regulating member, wherein the toner conveying member and the toner layer thickness regulating member are in contact with each other, and a developer coating blade having at least a rubber material on the surface of the developing roller. Used as a non-magnetic one-component developer(2) “The color toner contains an ester-based or olefin-based wax, and the average dispersed particle size of the wax in the toner is 0. The color toner for electrophotography as described in (1) above, which is 1 to 3 μm ”, (3)“As a method of mixing and coating the base toner with the external additive, the base toner, silica having a primary particle diameter of 0.01 to 0.03 μm, and a primary particle diameter of 0.01 to 0.03 μm are used. Surface area 60-140m ² / G hydrophobized titanium oxide was mixed, and then the specific surface area 20-50 m ² / G, hydrophobized silica having a bulk density of 100 to 250 g / l is added and mixed.(1) characterized in thatOr (2)(4) “Color toner for electrophotography”Uses metal salt compounds of salicylic acid derivatives as charge control agents(1) characterized in thatOr any of items (3)Color toner for electrophotography as described inToThis is achieved.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The contents of the present invention will be specifically shown below.
In order to achieve the object of the present invention, a volume average particle size of a base toner in a base toner composed mainly of at least a binder resin, a colorant and a charge control agent and an external additive is 6. 5 to 9.5 μm, 2 to 15% by number of particles of 5 μm or less, and volume average particle diameter / number average particle diameter = 1.15 to 1.25. Even if the balance of the toner is performed, fluctuations in the particle diameter of the toner in the developer are reduced, and good and stable developability can be obtained even with long-term stirring in the developing device. In addition, even when used as a one-component developer, fluctuations in the particle size of the toner are reduced even when the balance of the toner is performed, and the filming of the toner on the developing roller and the layering of the toner are reduced. There was no fusion of toner to a member such as a blade, and good and stable developability and images were obtained even during long-term use (stirring) of the developing device.
[0020]
In general, it is said that the smaller the toner particle size, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. . Further, when the volume average particle diameter is smaller than the range of the present invention, in the case of a two-component developer, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the charging ability of the carrier is reduced. When used as a developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur.
Further, these phenomena are the same for the toner having a fine powder content larger than the range of the present invention.
[0021]
On the contrary, when the particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high resolution and high quality image, and when the balance of the toner in the developer is performed, In many cases, the variation of the particle size becomes large. It was also clarified that the same applies when the volume average particle diameter / number average particle diameter is larger than 1.25.
Further, when the volume average particle diameter / number average particle diameter is smaller than 1.15, there are preferable aspects from the viewpoint of stabilizing the behavior of the toner and equalizing the charge amount, but the toner cannot be sufficiently charged. As a result, it became clear that the cleaning property may be deteriorated.
[0022]
In addition, since the color toner contains an ester-based and / or olefin-based wax, and the average dispersion particle size of the wax in the toner is 0.1 to 3 μm, the characteristics relating to fixing and the stable It became clear that developability is compatible.
[0023]
By containing these waxes, sufficient offset resistance can be obtained by sufficient exudation of the wax from the toner surface at the time of fixing, and the transparency of the toner is not deteriorated. The dispersion of the toner becomes good, and even when the developer is stirred for a long time in the developing device, it is possible to prevent the wax from seeping out from the surface of the toner and the wax from being detached. It has been clarified that filming and toner fusion to a member such as a blade for thinning the toner can be prevented.
[0024]
It has been found that ester-based and / or olefin-based waxes particularly improve offset resistance. Since these waxes are incompatible with polyester resins and polyol resins generally used for color toners, they are easily dispersed uniformly, so that high offset resistance can be imparted to the toner.
[0025]
Here, the ester wax refers to a wax having an ester bond, and includes natural waxes such as candelilla wax, carnauba wax, rice wax, and montan wax, and those prepared by synthesis. Examples of the olefin wax include polyethylene wax and polypropylene wax.
[0026]
Further, when the average dispersed particle diameter of the wax in the toner is smaller than 0.1 μm, it may be difficult to seep out to the toner surface at the time of fixing, and offset resistance may not be obtained. On the other hand, if it is larger than 3 μm, the fluidity of the toner is deteriorated and the efficiency during production is deteriorated, or in the case of a two-component developer due to the separation of the wax from the toner surface, the carrier surface is contaminated and the charging characteristics are reduced. In the case of a one-component developer, the toner tends to be deteriorated, or toner filming on the developing roller or carrier, and toner fusion to a member such as a blade for thinning the toner are likely to occur.
[0027]
In particular, the DSC melting point of the wax is preferably 70 to 130 ° C., and when the wax is too low in the process of dispersing the wax in the toner when the toner is kneaded, the wax melts. If it is too much, it will be difficult to apply a shearing force, and sufficient wax dispersion will not be achieved. On the other hand, if the melting point of the wax is too high, the wax will not sufficiently ooze out on the toner surface during fixing, and offset resistance cannot be obtained. That is, generally, when wax is added to the toner, the fluidity of the toner is deteriorated, and there is a tendency that problems such as deterioration in efficiency during production and toner supply to the developing unit are likely to occur. On the other hand, the wax having the constitution of the present invention does not deteriorate the fluidity of the toner, and good productivity and toner supply to the developing unit can be obtained.
[0028]
In particular, regarding the one-component development, in order to achieve the object of the present invention, it is necessary that the characteristics of the toner are as follows.
1. Toner is uniformly supplied on the developing roller, and the toner layer on the developing roller is uniformly formed.
2. The toner on the developing roller is sufficiently charged, and the level of the amount of charge is little changed depending on the long-term agitation of the developing roller and the usage environment.
3. Even when the developing roller is agitated for a long time, streaks or the like due to the fusion of the toner to the developing roller or the member for thinning the toner should not occur.
[0029]
  As a result of the study by the present inventors, in the color toner composed of the base toner having the particle diameter of the present invention mainly composed of at least the binder resin, the colorant, and the charge control agent, and the external toner, the external additive The following three types:
(I)0.2 to 1.0 parts by weight of hydrophobically treated silica having a primary particle size of 0.01 to 0.03 μm with respect to 100 parts by weight of the base toner,
( ii )Primary particle size 0.01-0.03 μm and specific surface area 60-140 m²/ G hydrophobized titanium oxide of 0.2 to 0.8 parts by weight with respect to 100 parts by weight of the base toner,
( iii )Specific surface area 20-50m²/ G, 0.5 to 2.0 parts by weight of hydrophobized silica having a bulk density of 100 to 250 g / l, based on 100 parts by weight of the base toner,
These were achieved by containing together.
[0030]
That is, it is necessary for the toner by adhering the hydrophobic treated silica having a primary particle diameter of 0.01 to 0.03 μm to the surface of the toner of 0.2 to 1.0 part by weight with respect to 100 parts by weight of the base toner. Fluidity and chargeability are imparted, and the developing property on the developing roller and from the developing roller to the photoreceptor is improved.
The addition amount of this type of silica is preferably 0.2 to 1.0 part by weight with respect to 100 parts by weight of the base toner. If less than this, the necessary amount of toner is supplied to the developing roller. In some cases, the required charge amount of the toner cannot be obtained. In addition, if it is added more than this, the chargeability of the toner is too high, and sufficient toner development may not be performed, or the toner may scatter from the developing roller.
[0031]
The primary particle diameter is 0.01 to 0.03 μm and the specific surface area is 60 to 140 m.²/ G of hydrophobized titanium oxide is adhered to the surface of the toner in an amount of 0.2 to 0.8 parts by weight with respect to 100 parts by weight of the base toner, thereby stabilizing the charging property of the toner, particularly Charge-up is prevented.
[0032]
In addition, when the addition amount of this type of titanium oxide is less than this, the chargeability of the toner may be too high and sufficient toner development may not be performed. In addition, if it is added more than this, the chargeability of the toner is too low, and the toner may scatter from the developing roller or cause background stains.
[0033]
Also, specific surface area 20-50m²/ G, a silica having a bulk density of 100 to 250 g / l, is applied on the toner developing roller by adhering 0.5 to 2.0 parts by weight of the surface of the toner with respect to 100 parts by weight of the base toner. The thin layer becomes uniform, and the unevenness of the thin layer is greatly improved. Further, by the stirring of the developing roller for a long period of time, the occurrence of white stripes due to the fusion of the toner to the stirring developer coating blade is prevented.
[0034]
If the addition amount of this type of silica is less than this, the thin layer of toner on the developing roller becomes non-uniform, so that uniform development of toner and images cannot be obtained, or a stir developer coating blade White streaks may occur due to toner fusion to the toner. If more than this is added, this type of silica is excessively present and does not adhere to the surface of the toner, which may impair the charging stability of the toner.
[0035]
In addition, the silica used in the present invention is generally produced by a wet method or a dry method, and is particularly called so-called fumed silica produced by a dry method (vapor phase oxidation of a silicon halide compound). It is preferable from the viewpoint of fluidity. This is manufactured by a conventionally known technique. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction is as follows.
[0036]
[Chemical 1]
SiCl_Four+ 2H₂+ O₂→ SiO₂+ 4HCl
In this production process, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. Conjugate.
[0037]
As a method for hydrophobizing silica fine powder, the surface of the silica fine powder can be surface-treated with a silane compound or the like.
That is, the silane compound is reacted with the hydrogen group bonded to the silica fine powder, and the hydroxyl group is substituted with a siloxyl group, etc. Therefore, the degree of hydrophobicity is the above reaction among the hydroxyl groups that existed before hydrophobization. Is the proportion of hydroxyl groups lost due to. The hydrophobizing treatment is performed by reacting a fine silica powder with a dialkyl dihalogenated silane, a trialkyl halogenated silane, a hexaalkyldisilazane, an alkyl trihalogenated silane, or the like at a high temperature.
[0038]
The degree of hydrophobicity of the silica fine powder can be measured by the following method.
Add 50 ml of water to a 200 ml beaker and add 0.2 g of fine silica powder. And while gently stirring with a magnetic stirrer, add methanol from the burette where the tip was immersed in water at the time of dropping, the floating silica fine powder began to sink, read the ml number of dripped methanol when completely sinked,
Degree of hydrophobicity = {appropriate number of ml of methanol / (50 + number of ml of dropped methanol)} × 100 (%) Methanol acts as a surfactant in this case, and the silica fine powder that floats with the addition of methanol is dispersed in water via methanol, so the higher the value of the degree of hydrophobicity, the higher the degree of hydrophobicity of the silica fine powder. Is expensive.
[0039]
In addition, the titanium oxide fine particles used in the present invention include those produced by the sulfuric acid method and the chlorine method, and all of the rutile type, anatase type, amorphous type, and mixed types thereof are used within the scope of the present invention. Is possible. The hydrophobizing treatment can be performed with the same compound as silica.
[0040]
Furthermore, the toner of this constitution is used by using the color toner for one-component development in a developing roller made of at least a metallic material and a developing device in which the developing roller is in contact with a developer coating blade having a rubber material on the surface. Exerts a great effect on the object of the present invention. When the toner of the present invention is used, the toner thin layer on the developing roller becomes uniform by using the metal developing roller, and the unevenness of the thin layer is greatly improved. The toner amount on the developing roller is stabilized.
[0041]
Further, as a method for mixing and coating the external toner to the base toner, the base toner, silica having a primary particle diameter of 0.01 to 0.03 μm and hydrophobized silica, and a primary particle diameter of 0.01 to 0.03 μm are used. Specific surface area of 60-140m²/ G hydrophobized titanium oxide was mixed, and then the specific surface area 20-50 m²/ G, silica having a bulk density of 100 to 250 g / l is added and mixed to prevent the external additive from being detached from the toner surface, and between the developing roller and the developer coating blade. The toner thin layer unevenness due to the presence of the external additive is improved. That is, when the base toner and all the external additives are mixed at the same time, the external additives tend to aggregate with each other and may not adhere uniformly to the surface of the toner, and the above phenomenon may occur. is there.
[0042]
Furthermore, by using a metal salt compound of a salicylic acid derivative as the charge control agent of the color toner of the present invention, a stable toner charge can be obtained while obtaining a uniform toner thin layer especially on the developing roller in a one-component developing device. Characteristics can be obtained.
This compound
[0043]
[Chemical 2]

(However, in the formula, R^Three, R^FourAnd R^FiveIs a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an allyl group, and a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an allyl group is particularly desirable. Where R^Three, R^FourAnd R^FiveMay be the same or different at the same time. Me is any metal selected from zinc, nickel, cobalt, copper and chromium. )
[0044]
This compound is also disclosed in Clark, J, L, Kao, H (1948) J. et al. Amer. Chem. Soc. 70, 2151 can be easily synthesized. For example, 2 mol of salicylic acid sodium salt (including a sodium salt of a salicylic acid derivative) and 1 mol of zinc chloride are mixed in a solvent, mixed, heated and stirred to obtain a zinc salt.
This metal salt is a white crystal and does not show coloration when dispersed in a toner binder. A metal salt other than a zinc salt can also be produced according to the above method.
The compounding quantity of this compound is 0.1-10 weight part with respect to 100 weight part of binder resin, Preferably it is about 0.5-5 weight part.
Specific examples of this compound include those shown below.
[0045]
[Chemical 3]

[0046]
[Formula 4]

[0047]
[Chemical formula 5]

[0048]
[Chemical 6]

[0049]
[Chemical 7]

[0050]
[Chemical 8]

[0051]
[Chemical 9]

[0052]
[Chemical Formula 10]

[0053]
As the binder resin used in the color toner of the present invention, various types selected from transparency, glossiness, fixability, chargeability and the like necessary for the color toner are used. Resins are preferred.
There are various types of polyester resins, but the following are preferable in order to maintain the characteristics required for the color toner.
[0054]
Embedded image

(Where R¹Is an alkylene group having 2 to 4 carbon atoms, x and y are positive integers, and the average value of the sum is 2 to 16. And the following general formula (II) or (III) selected from the group consisting of divalent or higher polyvalent carboxylic acids, anhydrides thereof and lower alkyl esters thereof:
[0055]
Embedded image

[0056]
Embedded image

(Where R², R^ThreeIs a saturated or unsaturated hydrocarbon group having 4 to 20 carbon atoms. ) Or an acid component containing an anhydride thereof, or trimellitic acid, or an acid component containing an anhydride thereof, and a polyester resin obtained by condensation polymerization.
[0057]
Moreover, compounds such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, their anhydrides and their lower alkyl esters can be used as the remaining components of the general formulas (II) and (III).
Examples of the compound represented by the general formula (II) or (III) include n-dodecenyl succinic acid, n-dodecyl succinic acid, n-butyl succinic acid, iso-dodecenyl succinic acid, iso-octyl succinic acid and the like. Acid derivatives are mentioned, and particularly when these are used, the fixing property at a low temperature as a toner is sufficient and the gloss is further improved.
[0058]
Examples of the diol represented by the general formula (I) include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyester (2) -2,2- Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (16) -2,2-bis (4-hydroxyphenyl) propane, etc. Is mentioned.
In addition, about 5 mol% or less of polyhydroxy compounds having two or more functional groups as described below can be used for the diol component. Ethylene glycol, propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or etherified polyhydroxyl compounds thereof.
The polyester resin can be usually produced by polycondensing a polyol component and a polyvalent carboxylic acid component at a temperature of 180 to 250 ° C. in an inert gas atmosphere.
[0059]
Various types of polyol resins can be used, but the following are preferred as those used in the present invention. That is, in particular, as a polyol resin, (1) an epoxy resin, (2) a dihydric phenol alkylene oxide adduct or its glycidyl ether, and (3) a compound having one active hydrogen in the molecule that reacts with an epoxy group. And (4) it is preferable to use a polyol obtained by reacting a compound having two or more active hydrogens in the molecule which reacts with an epoxy group. Furthermore, the epoxy resin (1) is particularly preferably at least two or more bisphenol A type epoxy resins having different number average molecular weights. This polyol resin imparts good gloss and transparency, and is effective in offset resistance.
[0060]
The epoxy resin used in the present invention is preferably obtained by binding bisphenol such as bisphenol A or bisphenol F and epichlorohydrin. In order to obtain stable fixing characteristics and gloss, the epoxy resin is at least two types of bisphenol A type epoxy resins having different number average molecular weights. The low molecular weight component has a number average molecular weight of 360 to 2000, and has a high molecular weight component. The number average molecular weight is preferably 3000 to 10,000. Further, it is preferable that the low molecular weight component is 20 to 50 wt% and the high molecular weight component is 5 to 40 wt%. When the amount of the low molecular weight component is too large or the molecular weight is lower than the molecular weight 360, there is a possibility that the gloss is too high or the storage stability is deteriorated. Further, when the amount of the high molecular weight component is too large or the molecular weight is higher than 10,000, the gloss may be insufficient.
[0061]
Examples of the compound used in the present invention include the following as the alkylene oxide adduct of dihydric phenol. That is, reaction products of ethylene oxide, propylene oxide, butylene oxide and mixtures thereof with bisphenols such as bisphenol A and bisphenol F can be mentioned. The resulting adduct may be used after glycidylation with epichlorohydrin or β-methylepichlorohydrin. In particular, diglycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (IV) is preferable.
[0062]
Embedded image

[0063]
Moreover, it is preferable that 10-40 wt% of the alkylene oxide adduct of dihydric phenol or its glycidyl ether is contained with respect to polyol resin. If the amount is too small, problems such as an increase in curl occur, and if n + m is 7 or more, or if the amount is too large, gloss may be excessively produced, and storage stability may be deteriorated. Examples of the compound having one active hydrogen in the molecule that reacts with the epoxy group used in the present invention include monohydric phenols, secondary amines, and carboxylic acids. The following are illustrated as monohydric phenols. Examples include phenol, cresol, isopropylphenol, aminophenol, nonylphenol, dodecylphenol, xylenol, and p-cumylphenol. Secondary amines include diethylamine, dipropylamine, dibutylamine, N-methyl (ethyl) piperazine, piperidine and the like. Examples of carboxylic acids include propionic acid and caproic acid.
[0064]
In order to obtain a polyol resin having an epoxy resin portion and an alkylene oxide portion in the main chain of the present invention, various raw materials can be combined. For example, it can be obtained by reacting an epoxy resin having a glycidyl group at both ends and an alkylene oxide adduct of a dihydric phenol having both glycidyl groups with a dihalide, diisocyanate, diamine, dithiol, polyhydric phenol, or dicarboxylic acid. Among these, it is most preferable to react divalent phenol from the viewpoint of reaction stability. Moreover, it is also preferable to use polyhydric phenols and polyhydric carboxylic acids in combination with dihydric phenols as long as they do not gel. Here, the amount of polyphenols and polycarboxylic acids is 15% or less, preferably 10% or less, based on the total amount.
[0065]
Examples of the compound having two or more active hydrogens in the molecule that react with the epoxy group used in the present invention include dihydric phenols, polyhydric phenols, and polycarboxylic acids. Examples of the dihydric phenol include bisphenols such as bisphenol A and bisphenol F. Examples of polyhydric phenols include orthocresol novolacs, phenol novolacs, tris (4-hydroxyphenyl) methane, and 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] benzene. Examples of the polyvalent carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, trimellitic acid, and trimellitic anhydride.
[0066]
Further, since these polyester resins and polyol resins are difficult to obtain transparency and gloss when having a high crosslinking density, they are preferably non-crosslinked or weakly crosslinked (THF insoluble content is 5 wt% or less). It is preferable.
Moreover, it is not limited to these types of resins, and publicly known ones can be used as necessary.
[0067]
As the binder resin used in the present invention, the following may be added in addition to those described above.
For example, styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and homopolymers of substituted styrene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, Styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer Polymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene -Vinyl ethyl ether copolymer Styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Styrene copolymer: Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, etc. It is done.
[0068]
In particular, in order to obtain appropriate gloss, transparency, and fixability for a color image, the 1/2 outflow start temperature of the binder resin used for the toner is preferably 110 to 130 ° C. The 1/2 outflow start temperature can be measured as follows.
That is, using an elevated flow tester (CFT-500: manufactured by Shimadzu Corporation), the diameter of the die pore is 1 mm, and the pressure is 20 kg / cm.²1 cm under the condition of a heating rate of 6 ° C./min^ThreeThe temperature corresponding to ½ of the height from the outflow start point to the outflow end point when the sample is melted out.
[0069]
Furthermore, as the colorant used in the toner of the present invention, a dye / pigment capable of obtaining toners of yellow, magenta, cyan and black colors can be used.
For example, carbon black, lamp black, ultramarine, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6G, lake, chalcoil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, etc. Any conventionally known dyes and pigments such as dyes and pigments can be used alone or in combination.
[0070]
The charge control agent used in the toner of the present invention is particularly preferably a metal salt of the aforementioned salicylic acid derivative, but if necessary, a transparent or white substance that does not impair the color tone of the color toner may be added. Thus, the toner can be stably charged. Specifically, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene compounds and the like are used, but are not limited thereto.
In addition to the hydrophobic silica and titanium oxide used in the present invention, as an external additive, alumina, and fatty acid metal salts, polyvinylidene fluoride, etc. are added if necessary. You may do it.
[0071]
【Example】
EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.
Further, the characteristic measurement regarding the fixing was performed as follows.
(1) Temperature range where no offset occurs
Using a Ricoh color copier pre-tail 550, a solid image consisting of red, blue and green as a single color and intermediate colors of yellow, magenta, cyan and black on a transfer paper (Ricoh type 6000-70W) 1.0 ± 0.1 mg / cm²The toner was developed so that the toner was developed, the fixing unit was remodeled, and the temperature of the fixing roller was adjusted to be variable, and the density at which no offset was generated was measured. The fixing roller was evaluated under the condition that no oil was applied.
[0072]
▲ 2 ▼ Glossiness
In the monochromatic image sample, the glossiness of the sample when the fixing roller surface temperature was 160 ° C. was measured with a gloss meter manufactured by Nippon Denshoku Industries Co., Ltd. at an incident angle of 60 °. The glossiness becomes higher as the value becomes higher. As a full-color copy image, moderate gloss is preferred, and about 10 to 40% is preferable.
[0073]
▲ 3 ▼ Haze degree
Using the above-mentioned monochromatic image sample as a transfer paper, Ricoh's OHP sheet (type PPC-DX), the degree of haze of the sample when the surface temperature of the fixing roller is 160 ° C. is directly read by Suga Test Instruments Co., Ltd. Measured with a computer HGM-2DP type.
The haze degree is also referred to as haze, and is measured as a measure of the transparency of the toner. The lower the value, the higher the transparency, and the better the color developability when an OHP sheet is used. Further, the haze value indicating good color developability is preferably 30% or less, particularly preferably 20% or less.
[0074]
Moreover, the characteristic measurement related to the one-component developer was performed as follows.
(4) Toner characteristics on developing roller
(Evaluation equipment)
The developing device (developing roller (2) shown in FIG. 1 is composed mainly of a silicone resin as a surface layer or made of a metal material, and a toner supply roller (3) made of a polyurethane material that comes into contact with the developing roller, Further, toner is supplied to a blade (4) made of a urethane material that is in contact with the developing roller (set as shown in FIG. 1). In FIG. 1, (1) is a latent image carrier (belt photoconductor), (2) is a developing roller, (2-1) is a metal core, (2-2) is a resin coating layer, and (3) is a toner supply. (4) is a developer coating blade, (5) is an agitator, and (6) is a development region.
[0075]
(4) -1 Charge amount (4) -2 Toner adhesion amount
Charge amount is measured by a suction method specific charge measuring device that sucks the toner on the developing roller through a Faraday cage equipped with a filter layer on the outlet side and measures the specific charge of the toner trapped in the Faraday cage. Do. Further, the toner adhesion amount is calculated from the relationship between the weight of the toner trapped at the same time and the area of the attracted developing roller.
The appropriate values of these characteristics differ depending on the linear velocity (ratio) between the developing roller and the photoconductor, but are generally as follows. In particular, they are stable even by long-term stirring of the developing roller with a large number of prints. It is preferable from the viewpoint of stabilizing the amount of toner to be developed.
Charge amount 10-25 (μc / g) in absolute value
Adhesion amount 0.4-1.2 (mg / cm²)
[0076]
(4) -3 Toner thin layer property
The thin layer property of the toner on the developing roller was visually observed. Further, after long-term stirring of the developing roller, the developing unit was disassembled, and after removing the toner, the filming state of the toner on the developing roller and the fixing state of the toner to the developer coating blade were visually observed.
[0077]
Example 1(Reference example)
・ Binder resin 1
    (Polyester resin, 1/2 outflow start temperature: 126 ° C.) 100 parts by weight
・ Charge control agent
    (Fluorine-containing quaternary ammonium salt compound) 3 parts by weight
・ Coloring agent
    <For yellow toner>
      Disazo yellow pigment (C.I. Pigment Yellow 17) 5 parts by weight
    <For magenta toner>
      Quinacridone magenta pigment (C.I. Pigment Red 184) 4 parts by weight
    <For cyan toner>
      Copper phthalocyanine blue pigment (C.I. Pigment Blue 15) 2 parts by weight
    <For black toner>
      5 parts by weight of carbon black
[0078]
The above materials were sufficiently mixed with a blender for each color, and then melt-kneaded with two rolls heated to 100 to 110 ° C. The kneaded product was allowed to cool naturally, then coarsely pulverized by a cutter mill, pulverized by a fine pulverizer using a jet stream, and then a matrix colored particle of each color was obtained using an air classifier. In addition, the volume average particle diameter of each color matrix colored particle was as follows. (The volume average particle diameter of the toner was measured with a Coulter Counter Model TA-II manufactured by Coulter Electronics.)
Yellow: 8.1 (μm), Magenta: 8.3 (μm)
Cyan: 8.4 (μm), Black: 8.4 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0079]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. In addition, the mixing method of an external additive is shown in Table 1.
[0080]
Further, 5 parts by weight of the present toner and a silicone resin coated (average resin film thickness: 0.3 μm) and 95 parts by weight of a ferrite carrier having an average particle diameter of 50 μm were mixed by a ball mill to obtain a developer. The charge amount of the developer was −22 (μc / g).
[0081]
The obtained toner and developer were set in a modified Ricoh PRETER650 machine (the oil supplied to the fixing roller was not used), and 30,000 sheets were printed. The image was clear and there was little change in 30,000 prints. Further, the change in the charge amount was small. A summary of the evaluation results is shown in Table 1.
[0082]
Example 2(Reference example)
・ Binder resin
    (Polyester resin, 1/2 outflow start temperature: 120 ° C.) 100 parts by weight
・ Charge control agent
    (Fluorine-containing quaternary ammonium salt compound) 3 parts by weight
·Release agent
    (Low molecular weight polypropylene, melting point: 118 ° C.) 3.5 parts by weight
・ Coloring agent
    Same as Example 1
[0083]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 7.7 (μm), magenta: 7.5 (μm)
Cyan: 7.6 (μm), Black: 7.4 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0084]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

Were mixed with a Henschel mixer to produce toners of each color of yellow, magenta, cyan, and black. Developers were prepared in the same manner as in Example 1, and the same evaluation was performed. Even after printing 30,000 sheets, there was little change in image and little change in charge amount. Furthermore, when the offset non-occurrence temperature range, the glossiness, and the haze degree were evaluated by the method described above, good results were obtained in all cases.
[0085]
Example 3(Reference example)
・ Binder resin
    (Polyester resin, 1/2 outflow start temperature: 121 ° C.) 100 parts by weight
・ Charge control agent
    (Fluorine-containing quaternary ammonium salt compound) 3 parts by weight
·Release agent
    (Ester wax, melting point: 85 ° C.) 4 parts by weight
・ Coloring agent
    Same as Example 1
[0086]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 8.5 (μm), magenta: 8.5 (μm)
Cyan: 8.8 (μm), Black: 8.7 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0087]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. The obtained toner was set in a modified machine of Ricoh's Myricopy M-5, and the characteristics of the toner layer on the developing roller were evaluated. The toner thin layer on the developing roller was uniform and remained unchanged after printing 30,000 sheets, and the change in the charge amount and the toner adhesion amount was small. Further, the same fixing performance as in Example 2 was evaluated, and good results were obtained as in Example 2. A summary of the evaluation results is shown in Table 1.
[0088]
Example 4(Reference example)
・ Binder resin
    (Polyol resin, 1/2 outflow start temperature: 116 ° C.) 100 parts by weight
・ Charge control agent
    (Fluorine-containing quaternary ammonium salt compound) 4 parts by weight
·Release agent
    (Low molecular weight polypropylene, melting point: 110 ° C.) 4 parts by weight
・ Coloring agent
    Same as Example 1
[0089]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 6.7 (μm), magenta: 6.9 (μm)
Cyan: 6.8 (μm), Black: 6.6 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0090]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Furthermore, when the same evaluation as in Example 3 was performed, the same good results as in Example 3 were obtained. Further, the same fixing performance as in Example 2 was evaluated, and good results were obtained as in Example 2. A summary of the evaluation results is shown in Table 1.
[0091]
Example 5

[0092]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 9.0 (μm), Magenta: 9.2 (μm)
Cyan: 9.0 (μm), Black: 9.1 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0093]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Furthermore, when the same evaluation as in Example 3 was performed, the same good results as in Example 3 were obtained. Further, the same fixing performance as in Example 2 was evaluated, and good results were obtained as in Example 2. A summary of the evaluation results is shown in Table 1.
[0094]
Example 6

[0095]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 9.4 (μm), magenta: 9.1 (μm)
Cyan: 9.3 (μm), Black: 9.2 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0096]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Furthermore, when the same evaluation as in Example 3 was performed, the same good results as in Example 3 were obtained. Further, the same fixing performance as in Example 2 was evaluated, and good results were obtained as in Example 2. A summary of the evaluation results is shown in Table 1.
[0097]
Example 7

[0098]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 8.8 (μm), magenta: 9.2 (μm)
Cyan: 9.0 (μm), Black: 9.2 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0099]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Furthermore, when the same evaluation as in Example 3 was performed, the same good results as in Example 3 were obtained. Further, the same fixing performance as in Example 2 was evaluated, and good results were obtained as in Example 2. A summary of the evaluation results is shown in Table 1.
[0100]
Comparative Example 1

[0101]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 7.5 (μm), Magenta: 7.3 (μm)
Cyan: 7.6 (μm), Black: 7.4 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0102]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Further, in the same manner as in Example 1, mixing with a carrier was performed to obtain a developer. Furthermore, when the same evaluation as in Example 1 was performed, the charge amount of the developer decreased as the prints were overlapped, and background staining occurred on the background portion of the image. A summary of the evaluation results is shown in Table 1.
[0103]
Comparative Example 2

[0104]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 6.0 (μm), magenta: 6.1 (μm)
Cyan: 6.3 (μm), Black: 5.9 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0105]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Further, when the same evaluation as in Example 3 was performed, the amount of charge decreased after printing 30,000 sheets, the toner thin layer became non-uniform, and the toner dropped from the developing roller. A summary of the evaluation results is shown in Table 1.
[0106]
Comparative Example 3

[0107]
The above material was treated in the same manner as in Example 1 to obtain matrix colored particles having the following volume average particle diameter.
Yellow: 7.6 (μm), magenta: 7.7 (μm)
Cyan: 7.5 (μm), Black: 7.8 (μm)
In addition, Table 1 shows the number% of particles of 5 μm or less and the volume average particle diameter / number average particle diameter.
[0108]
Furthermore, as an external additive with respect to 100 parts by weight of the base colored particles,

The toner was mixed with a Henschel mixer to obtain yellow, magenta, cyan, and black toners. Further, the same evaluation as in Example 3 was performed. As a result, the charge amount was low from the initial stage, and toner was dropped from the developing roller. A summary of the evaluation results is shown in Table 1.
[0109]
[Table 1-1]

[0110]
[Table 1-2]

[0111]
[Table 1-3]

[0112]
[Table 1-4]

[0113]
[Table 1-5]

[0114]
[Table 1-6]

[0115]
【The invention's effect】
  As described above, as is clear from the detailed and specific description, the color toner of the present invention is a color toner comprising at least a base toner mainly composed of a binder resin, a colorant, and a charge control agent, and an external additive. The base toner has a volume average particle diameter of 6.5 to 9.5 μm, 2 to 15% by number of particles of 5 μm or less, and volume average particle diameter / number average particle diameter = 1.15 to 1.25. In addition, a stable image and charge amount can be maintained even during long-term use.Further, as an external additive of the color toner, (i) hydrophobic treated silica having a primary particle diameter of 0.01 to 0.03 μm is added in an amount of 0.2 to 1.0 part by weight based on 100 parts by weight of the base toner. , ( ii ) Primary particle size 0.01-0.03 μm and specific surface area 60-140 m ² / G hydrophobized titanium oxide of 0.2 to 0.8 parts by weight with respect to 100 parts by weight of the base toner ( iii ) Specific surface area 20-50m ² / G and hydrophobized silica having a bulk density of 100 to 250 g / l is added on the developing roller by adding 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the base toner. The toner thin layer becomes uniform, and the uniformity of the thin layer can be maintained even during long-term stirring. In addition, the color toner of the present invention is used in a developing device that includes at least a toner conveying member and a toner layer thickness regulating member, and the toner conveying member and the toner layer thickness regulating member are in contact with each other, so that the toner can be stably used for a long time Image and charge amount can be maintained. In addition, the toner on the developing roller is used by using the color toner for one-component development in a developing roller made of at least a metal material and a developing device in which the developing roller is in contact with a developer coating blade having a rubber material on the surface. The characteristics can be further stabilized.In addition, the color toner contains an ester-based or olefin-based wax, and the average dispersion particle size of the wax in the toner is 0.1 to 3 μm, so that it is stable even in long-term use. Image and charge amount can be maintained. MaIn addition, as a method for mixing and coating the external additive on the base toner, the base toner, silica having a primary particle diameter of 0.01 to 0.03 μm and hydrophobized silica, and a primary particle diameter of 0.01 to 0.03 μm are used. Specific surface area of 60-140m²/ G hydrophobized titanium oxide was mixed, and then the specific surface area 20-50 m²/ G and a silica having a bulk density of 100 to 250 g / l are added and mixed, whereby the toner characteristics on the developing roller can be further stabilized and maintained. In addition, charging of the color tonerSystemBy using a metal salt compound of a salicylic acid derivative as a control agent, the charging characteristics of the toner on the developing roller can be further stabilized and maintained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view centering on a developing roller portion showing an example of a developing device useful for using the toner of the present invention.
[Explanation of symbols]
1 Latent image carrier (belt photoreceptor)
2 Development roller
2-1 Core
2-2 Resin coat layer
3 Toner supply member
4 Developer application blade
5 Agitator
6 Development area

Claims (4)

In a color toner composed of at least a binder resin, a colorant, and a charge control agent as main components and an external additive, the volume average particle size of the base toner is 6.5 to 9.5 μm, and is 5 μm or less. particles 2 to 15% by number, Ri volume average particle size / number average particle diameter = 1.15 to 1.25 der, as an external additive, the (i) 1 primary particle diameter 0.01~0.03μm hydrophobic Hydrophobized silica having a specific surface area of 60 to 140 m ² / g with 0.2 to 1.0 parts by weight, ( ii ) primary particle diameter of 0.01 to 0.03 μm , based on 100 parts by weight of the base toner . Hydrophobized silica having a treated titanium oxide of 0.2 to 0.8 parts by weight, ( iii ) specific surface area of 20 to 50 m ² / g, and bulk density of 100 to 250 g / l based on 100 parts by weight of the base toner 0.5 to 2.0 weight per 100 weight parts of the base toner And a developing roller comprising at least a toner conveying member and a toner layer thickness regulating member, wherein the toner conveying member and the toner layer thickness regulating member are in contact with each other, and a developing roller made of at least a metal material , electrophotographic color toners, wherein Rukoto used as non-magnetic one-component developer is brought into contact with a developer coating blade developing apparatus having a developing roller the rubber material to the surface.   2. The electron according to claim 1, wherein the color toner contains an ester-based or olefin-based wax, and an average dispersed particle size of the wax in the toner is 0.1 to 3 μm. Color toner for photography. As a method of mixing and coating the base toner with the external additive, the base toner, silica having a primary particle diameter of 0.01 to 0.03 μm, and a primary particle diameter of 0.01 to 0.03 μm are used. was mixed with hydrophobized titanium oxide surface area 60~140m ² / g, a specific surface area of 20 to 50 m ² / g, mixing with the addition of hydrophobized silica having a bulk density of 100 to 250 g / l color toner for electrophotography according to claim 1 or 2, characterized in. As a charge control agent of the color toners, color toners for electrophotography according to any one of claims 1 to 3, characterized in that there use a metal salt compound of a salicylic acid derivative.

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