JP2004126251A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner having properties of fast processing, high picture quality, high durability and excellent environmental stability in a color electrophotographic apparatus equipped with contact electrification and contact transfer processes. <P>SOLUTION: The toner is used for the image forming method in which electrification is induced by a member in contact with an electrostatic charge image carrier, transfer is carried out by a member in contact with a transfer body, and a toner image is fixed by a thermal fixing means. At least two kinds of surface-treated silica fine particles having different BET specific surface areas are externally added to the toner. The difference in the BET specific surface area between silica fine particles (a) having the largest BET specific surface area and silica fine particles (b) having the second largest BET specific surface area is ≥30 m<SP>2</SP>/g. Both of the silica fine particles (a) and (b) are treated with a silane coupling agent. <P>COPYRIGHT: (C)2004,JPO

Description

ここにＡ：酸価
Ｂ：Ｎ／１０水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／１０水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）
【００２９】
本発明におけるトナーの円相当径、円形度、及びそれらの頻度分布とは、トナー粒子の形状を定量的に表現する簡便な方法として用いたものであり、本発明ではフロー式粒子像測定装置ＦＰＩＡ−１０００型（東亜医用電子社製）を用いて測定を行い、下式を用いて算出した。
【００３０】
【数２】

【００３１】
ここで、「粒子投影面積」とは二値化されたトナー粒子像の面積であり、「粒子投影像の周囲長」とは該トナー粒子像のエッジ点を結んで得られる輪郭線の長さと定義する。
【００３２】
本発明における円形度はトナー粒子の凹凸の度合いを示す指標であり、トナー粒子が完全な球形の場合には１．０００を示し、表面形状が複雑になる程、円形度は小さな値となる。
【００３３】
本発明において、トナーの個数基準の粒径頻度分布の平均値を意味する円相当個数平均径Ｄ１（μｍ）と粒径標準偏差ＳＤｄは、粒度分布の分割点ｉでの粒径（中心値）をｄｉ、頻度をｆｉとすると次式から算出される。
【００３４】
【数３】

【００３５】
また、円形度頻度分布の平均値を意味する平均円形度Ｃと円形度標準偏差ＳＤｃは、粒度分布の分割点ｉでの円形度（中心値）をｃｉ、頻度をｆ_ｃｉとすると、次式から算出される。
【００３６】
【数４】

【００３７】
具体的な測定方法としては、容器中に予め不純固形物などを除去したイオン交換水１０ｍｌを用意し、その中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルホン酸塩を加えた後、更に測定試料を０．０２ｇ加え、均一に分散させる。分散手段としては、超音波分散機ＵＨ−５０型（エスエムテー社製）に振動子として５φのチタン合金チップを装着したものを用い、５分間分散処理を行い、測定用の分散液とする。その際、該分散液の温度が４０℃以上にならないように適宜冷却する。
【００３８】
トナー粒子の形状測定には、前記フロー式粒子像測定装置を用い、測定時のトナー粒子濃度が３０００〜１万個／μｌとなるように該分散液濃度を再調整し、トナー粒子を１０００個以上計測する。計測後、このデータを用いてトナー粒子の円相当径や円形度頻度分布等を求める。
【００３９】
本発明のトナー母体を製造する方法は、公知の製造法を用いることができる。特に、本発明をより効果的なものとする球形トナーを容易に得ることができる、特公昭３６−１０２３１号公報、特開昭５９−５３８５６号公報、特開昭５９−６１８４２号公報に述べられている懸濁重合法を用いて直接トナーを生成する方法；単量体には可溶で水溶性重合開始剤の存在下で直接重合させてトナー粒子を生成するソープフリー重合法に代表される乳化重合法によるトナー粒子の製造などが好適である。また、マイクロカプセル製法のような界面重合法、ｉｎ　ｓｉｔｕ重合法、コアセルベーション法などの製造も挙げられる。さらに、特開昭６２−１０６４７３号公報や特開昭６３−１８６２５３号公報に開示されている様な、少なくとも１種以上の微粒子を凝集させ所望のトナーを得る界面会合法なども挙げられる。あるいは、粉砕法によって得られたトナーを、機械的衝撃力で球形化する方法などが挙げられる。
【００４０】
中でも、小粒径のトナー粒子が容易に得られる懸濁重合方法が特に好ましい。トナー粒子の製造方法として懸濁重合を利用する場合には、以下の如き製造方法によって直接的にトナー粒子を製造することが可能である。
【００４１】
単量体中に着色剤，重合開始剤，架橋剤，その他の添加剤を加え、ホモジナイザー，超音波分散機等によって均一に溶解又は分散せしめた単量体組成物を、分散安定剤を含有する水系媒体中に通常の撹拌機またはホモミキサー，ホモジナイザー等により分散せしめる。好ましくは単量体組成物の液滴が所望のトナー粒子のサイズを有するように撹拌速度・時間を調整し、造粒する。その後は、分散安定剤の作用により、粒子状態が維持され、且つ粒子の沈降が防止される程度の撹拌を行えば良い。重合温度は４０℃以上、通常５０〜９０℃（好ましくは５５〜８５℃）の温度に設定して重合を行う。重合反応後半に昇温しても良く、必要に応じＰＨ変更しても良い。本発明では、更に、トナーの定着時の臭いの原因となる未反応の重合性単量体、副生成物等を除去するために反応後半、又は、反応終了後に一部水系媒体を留去しても良い。反応終了後、生成したトナー粒子を洗浄・ろ過により収集し、乾燥する。
【００４２】
以下に重合法トナーの材料に関して記載する。
【００４３】
本発明のトナーを重合方法で製造する際に用いられる重合性単量体としては、ラジカル重合が可能なビニル系重合性単量体が用いられる。該ビニル系重合性単量体としては、主に単官能性重合性単量体を使用する。単官能性重合性単量体としては、スチレン；α−メチルスチレン、β−メチルスチレン、ο−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、２，４−ジメチルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン、ｐ−ｎ−ドデシルスチレン、ｐ−メトキシスチレン、ｐ−フェニルスチレンの如きスチレン誘導体；メチルアクリレート、エチルアクリレート、ｎ−プロピルアクリレート、ｉｓｏ−プロピルアクリレート、ｎ−ブチルアクリレート、ｉｓｏ−ブチルアクリレート、ｔｅｒｔ−ブチルアクリレート、ｎ−アミルアクリレート、ｎ−ヘキシルアクリレート、２−エチルヘキシルアクリレート、ｎ−オクチルアクリレート、ｎ−ノニルアクリレート、シクロヘキシルアクリレート、ベンジルアクリレート、ジメチルフォスフェートエチルアクリレート、ジエチルフォスフェートエチルアクリレート、ジブチルフォスフェートエチルアクリレート、２−ベンゾイルオキシエチルアクリレートの如きアクリル系重合性単量体；メチルメタクリレート、エチルメタクリレート、ｎ−プロピルメタクリレート、ｉｓｏ−プロピルメタクリレート、ｎ−ブチルメタクリレート、ｉｓｏ−ブチルメタクリレート、ｔｅｒｔ−ブチルメタクリレート、ｎ−アミルメタクリレート、ｎ−ヘキシルメタクリレート、２−エチルヘキシルメタクリレート、ｎ−オクチルメタクリレート、ｎ−ノニルメタクリレート、ジエチルフォスフェートエチルメタクリレート、ジブチルフォスフェートエチルメタクリレートの如きメタクリル系重合性単量体；メチレン脂肪族モノカルボン酸エステル；酢酸ビニル、プロピオン酸ビニル、酪酸ビニル、安息香酸ビニル、ギ酸ビニルの如きビニルエステル；ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテルの如きビニルエーテル；ビニルメチルケトン、ビニルヘキシルケトン、ビニルイソプロピルケトンの如きビニルケトンが挙げられる。
【００４４】
本発明においては、上記した単官能性重合性単量体を単独或いは、２種以上組み合わせて使用する。
【００４５】
上記した重合性単量体の重合の際に用いられる重合開始剤としては、油溶性開始剤及び／又は水溶性開始剤が用いられる。例えば、油溶性開始剤としては、２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス−２，４−ジメチルバレロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリルの如きアゾ化合物；アセチルシクロヘキシルスルホニルパーオキサイド、ジイソプロピルパーオキシカーボネート、デカノニルパーオキサイド、ラウロイルパーオキサイド、ステアロイルパーオキサイド、プロピオニルパーオキサイド、アセチルパーオキサイド、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ベンゾイルパーオキサイド、ｔ−ブチルパーオキシイソブチレート、シクロヘキサノンパーオキサイド、メチルエチルケトンパーオキサイド、ジクミルパーオキサイド、ｔ−ブチルヒドロパーオキサイド、ジ−ｔ−ブチルパーオキサイド、クメンヒドロパーオキサイドの如きパーオキサイド系開始剤が挙げられる。
【００４６】
水溶性開始剤としては、過硫酸アンモニウム、過硫酸カリウム、２，２’−アゾビス（Ｎ，Ｎ’−ジメチレンイソブチロアミジン）塩酸塩、２，２’−アゾビス（２−アミノジノプロパン）塩酸塩、アゾビス（イソブチルアミジン）塩酸塩、２，２’−アゾビスイソブチロニトリルスルホン酸ナトリウム、硫酸第一鉄又は過酸化水素が挙げられる。
【００４７】
重合性単量体の重合度を制御する為に、連鎖移動剤，重合禁止剤等を更に添加し用いることも可能である。
【００４８】
分散安定剤としては、リン酸三カルシウム，リン酸マグネシウム，リン酸アルミニウム，リン酸亜鉛，炭酸カルシウム，炭酸マグネシウム，水酸化カルシウム，水酸化マグネシウム，水酸化アルミニウム，メタケイ酸カルシウム，硫酸カルシウム，硫酸バリウム，ベントナイト，シリカ，アルミナ，ヒドロキシアパタイト等が挙げられる。通常単量体組成物１００質量部に対して水３００〜３０００質量部を分散媒体として使用するのが好ましい。
【００４９】
有機系化合物としては例えばポリビニルアルコール，ゼラチン，メチセルロース，メチルヒドロキシプロピルセルロース，エチルセルロース，カルボキシメチルセルロースのナトリウム塩，デンプン等が使用される。これら分散剤は、重合性単量体１００質量部に対して０．２〜２．０質量部を使用することが好ましい。
【００５０】
その他好ましく用いられる分散安定剤としては、硫酸，炭酸，燐酸，ピロ燐酸，ポリ燐酸の難水溶性金属塩があり、これらは分散媒中で高速撹拌下において酸アルカリ金属塩とハロゲン化金属塩との反応によって調製されることが好ましい。
【００５１】
これら分散剤の微細化のため０．００１〜０．１質量％の界面活性剤を併用しても良い。具体的には市販のノニオン，アニオン，カチオン型の界面活性剤が利用できる。例えばドデシル硫酸ナトリウム，テトラデシル硫酸ナトリウム，ペンタデシル硫酸ナトリウム，オクチル硫酸ナトリウム，オレイン酸ナトリウム，ラウリル酸ナトリウム，ステアリン酸カリウム，オレイン酸カルシウム等が好ましく用いられる。
【００５２】
本発明において縮合系化合物をトナー材料として用いる場合、その製造方法としては、例えば、酸化反応による合成法、カルボン酸及びその誘導体からの合成、マイケル付加反応に代表されるエステル基導入反応、カルボン酸化合物とアルコール化合物からの脱水縮合反応を利用する方法、酸ハロゲン化物とアルコール化合物からの反応、エステル交換反応で製造される。触媒としては、エステル化反応に使う一般の酸性、アルカリ性触媒、例えば酢酸亜鉛、チタン化合物などでよい。その後、再結晶法、蒸留法などにより高純度化させてもよい。
【００５３】
該縮合系化合物の特に好ましい製造方法は、原料の多用性、反応のしやすさからカルボン酸化合物とアルコール化合物からの脱水縮合反応である。この場合、全成分中４５〜５５ｍｏｌ％がアルコール成分であり、５５〜４５ｍｏｌ％が酸成分であることが好ましい。アルコール成分としては、エチレングリコール、プロピレングリコール、１，３−ブタンジオール、１，４−ブタンジオール、２，３−ブタンジオール、ジエチレングリコール、トリエチレングリコール、１，５−ペンタンジオール、１，６−ヘキサンジオール、ネオペンチルグリコール、２−エチル−１，３−ヘキサンジオール、水素化ビスフェノールＡ、下記式（Ｉ）
【００５４】
【化１】

（式中、Ｒはエチレン又はプロピレン基を示し、ｘ，ｙはそれぞれ１以上の整数を示し、かつｘ＋ｙの平均値は２〜１０を示す。）で示されるビスフェノール誘導体、又は下記式（ＩＩ）
【００５５】
【化２】

で示されるジオールの如きジオール類が挙げられる。
【００５６】
２価のカルボン酸としてはフタル酸、テレフタル酸、イソフタル酸、無水フタル酸、ジフェニル−Ｐ・Ｐ’−ジカルボン酸、ナフタレン−２，７−ジカルボン酸、ナフタレン−２，６−ジカルボン酸，ジフェニルメタン−Ｐ・Ｐ’−ジカルボン酸、ベンゾフェノン−４，４’−ジカルボン酸，１，２−ジフェノキシエタン−Ｐ・Ｐ’−ジカルボン酸の如きベンゼンジカルボン酸類又はその無水物；こはく酸、アジピン酸、セバシン酸、アゼライン酸、グリタル酸、シクロヘキサンジカルボン酸、トリエチレンジカルボン酸、マロン酸の如きアルキルジカルボン酸類又はその無水物、またさらに炭素数６〜１８のアルキル基又はアルケニル基で置換されたこはく酸もしくはその無水物；フマル酸、マレイン酸、シトラコン酸、イタコン酸の如き不飽和ジカルボン酸又はその無水物等が挙げられる。
【００５７】
特に好ましい該縮合系化合物のアルコール成分としては前記（Ｉ）式で示されるビスフェノール誘導体であり、酸成分としては、フタル酸、テレフタル酸、イソフタル酸又はその無水物、こはく酸、ｎ−ドデセニルコハク酸、又はその無水物、フマル酸、マレイン酸、無水マレイン酸の如きジカルボン酸が挙げられる。
【００５８】
該縮合系化合物は、２価のジカルボン酸及び２価のジオールから合成することにより得ることが可能である。場合により、３価以上のポリカルボン酸又はポリオールを本発明に悪影響を与えない範囲で少量使用しても良い。
【００５９】
３価以上のポリカルボン酸としては、トリメリット酸、ピロメリット酸、シクロヘキサントリカルボン酸類、２，５，７−ナフタレントリカルボン酸、１，２，４−ナフタレントリカルボン酸、１，２，４−ブタントリカルボン酸、１，２，５−ヘキサントリカルボン酸、１，３−ジカルボキシル−２−メチレンカルボキシルプロパン、１，３−ジカルボキシル−２−メチル−メチレンカルボキシルプロパン、テトラ（メチレンカルボキシル）メタン、１，２，７，８−オクタンテトラカルボン酸及びそれらの無水物が挙げられる。
【００６０】
３価以上のトリオールとしては、スルビトール、１，２，３，６−ヘキサンテトール、１，４−ソルビタン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ショ糖、１，２，４−メタントリオール、グリセリン、２−メチルプロパントリオール、２−メチル−１，２，４−ブタントリオール、トリメチロールエタン、トリメチロールプロパン、１，３，５−トリヒドロキシメチルベンゼンが挙げられる。
【００６１】
水系媒体中で直接的にトナー粒子を生成する場合には、重合性単量体１００質量部に対して１乃至３０質量部（より好ましくは、２〜２５質量部）極性樹脂を配合し、トナー粒子に含有されるのが良い。
【００６２】
本発明において用いられるトナーの離型剤としては、パラフィンワックス、ポリオレフィンワックス、マイクロクリスタリンワックス、フィッシャートロピッシュワックスの如きポリメチレンワックス、アミドワックス、ケトンワックス、高級脂肪酸、長鎖アルコール、エステルワックス及びこれらのグラフト化合物、ブロック化合物の如き誘導体等の低軟化点物質が挙げられ、これらは低分子量成分が除去されたＤＳＣ吸熱曲線の最大吸熱ピークがシャープなものが好ましい。また、これら２種類以上のブレンドでも構わない。
【００６３】
好ましく用いられるワックスとしては、炭素数１５乃至１００個の直鎖状のアルキルアルコール、直鎖状脂肪酸、直鎖状酸アミド、直鎖状エステルあるいは、モンタン系誘導体が挙げられる。これらワックスから液状脂肪酸の如き不純物を予め除去してあるものも好ましい。
【００６４】
さらに、好ましく用いられるワックスは、アルキレンを高圧下でラジカル重合あるいは低圧下でチーグラー触媒又は、その他の触媒を用いて重合した低分子量のアルキレンポリマー；高分子量のアルキレンポリマーを熱分解して得られるアルキレンポリマー；アルキレンを重合する際に副生する低分子量アルキレンポリマーを分離精製したもの、；一酸化炭素及び水素からなる合成ガスからアーゲ法により得られる炭化水素ポリマーの蒸留残分から、あるいは、蒸留残分を水素添加して得られる合成炭化水素から、特定の成分を抽出分別したポリメチレンワックスが挙げられる。これらワックスには酸化防止剤が添加されていてもよい。定着画像の透光性を向上させるためには、固体エステルワックスが好ましい。水系媒体中で直接的にトナー粒子を生成する場合には、重合性単量体１００質量部に対して１乃至４０質量部（より好ましくは３〜３０質量部）配合し、トナー粒子に含有されるのが良い。
【００６５】
本発明に用いられる着色剤は、カーボンブラックあるいは以下に示したような公知のイエロー／マゼンタ／シアン着色剤が利用される。
【００６６】
イエロー着色剤としては、縮合アゾ化合物，イソインドリノン化合物，アンスラキノン化合物，アゾ金属錯体，メチン化合物，アリルアミド化合物に代表される化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントイエロー１２、１３、１４、１５、１７、６２、７４、８３、９３、９４、９５、１０９、１１０、１１１、１２８、１２９、１４７、１６８、１８０等が好適に用いられる。
【００６７】
マゼンタ着色剤としては、縮合アゾ化合物，ジケトピロロピロール化合物，アントラキノン，キナクリドン化合物，塩基染料レーキ化合物，ナフトール化合物，ベンズイミダゾロン化合物，チオインジゴ化合物，ペリレン化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントレッド２、３、５、６、７、２３、４８；２、４８；３、４８；４、５７；１、８１；１、１２２、１４６、１６６、１５０、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４が特に好ましい。
【００６８】
本発明に用いられるシアン着色剤としては、銅フタロシアニン化合物及びその誘導体，アントラキノン化合物，塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．ピグメントブルー１、７、１５、１５：１、１５：２、１５：３、１５：４、６０、６２、６６等が特に好適に利用される。これらの着色剤は、単独又は混合し更には固溶体の状態で用いることができる。本発明の着色剤は、色相角，彩度，明度，耐侯性，ＯＨＰ透明性，トナー中への分散性の点から選択される。該着色剤の添加量は、樹脂１００質量部に対し１〜２０質量部添加して用いられる。
【００６９】
本発明のトナーは、荷電制御剤を含有しても良い。例えば、有機金属化合物、キレート化合物が有効であり、モノアゾ金属化合物、アセチルアセトン金属化合物、芳香族ハイドロキシカルボン酸、芳香族ダイカルボン酸系の金属化合物がある。他には、芳香族ハイドロキシカルボン酸、芳香族モノ及びポリカルボン酸及びその金属塩、無水物、エステル類、ビスフェノール等のフェノール誘導体類などがある。さらに、尿素誘導体、含金属サリチル酸系化合物、含金属ナフトエ酸系化合物、ホウ素化合物、４級アンモニウム塩、カリックスアレーン等が挙げられる。
【００７０】
あるいは、ニグロシン及び脂肪酸金属塩等によるニグロシン変性物、グアニジン化合物、イミダゾール化合物、トリブチルベンジルアンモニウム−１−ヒドロキシ−４−ナフトスルフォン酸塩、テトラブチルアンモニウムテトラフルオロボレートの如き４級アンモニウム塩、及びこれらの類似体であるホスホニウム塩の如きオニウム塩及びこれらのレーキ顔料、トリフェニルメタン染料及びこれらのレーキ顔料（レーキ化剤としては、りんタングステン酸、りんモリブデン酸、りんタングステンモリブデン酸、タンニン酸、ラウリン酸、没食子酸、フェリシアン化物、フェロシアン化物など）、高級脂肪酸の金属塩；ジブチルスズオキサイド、ジオクチルスズオキサイド、ジシクロヘキシルスズオキサイドの如きジオルガノスズオキサイド；ジブチルスズボレート、ジオクチルスズボレート、ジシクロヘキシルスズボレートの如きジオルガノスズボレート類が挙げられる。これらを単独で或いは２種類以上組合せて用いることができる。
【００７１】
シリカは、出発材料あるいは温度等の酸化の条件により、ある程度任意に、一次粒子の合一をコントロールできる。例えば、かかるシリカは硅素ハロゲン化物やアルコキシドの蒸気相酸化により生成されたいわゆる乾式法またはヒュームドシリカと称される乾式シリカ及びアルコキシド，水ガラス等から製造されるいわゆる湿式シリカの両者が使用可能であるが、表面及びシリカ微粉体の内部にあるシラノール基が少なく、またＮａ_２Ｏ，ＳＯ_３ ^２−の如き製造残滓の少ない乾式シリカの方が好ましい。また乾式シリカにおいては、製造工程において例えば、塩化アルミニウム，塩化チタン等他の金属ハロゲン化合物を硅素ハロゲン化合物と共に用いることによって、シリカと他の金属酸化物の複合微粉体を得ることも可能である。
【００７２】
シリカ微粒子の疎水化処理は、シランカップリング剤によって行われる。シランカップリング剤は、無機酸化物微粒子上の残存基あるいは吸着水と反応し均一な処理が達成され、トナーの帯電の安定化，流動性付与の点で好ましい。
【００７３】
シランカップリング剤は、例えば下記一般式
ＲｍＳｉＹｎ
Ｒ：アルコキシ基
ｍ：１〜３の整数
Ｙ：アルキル基
ビニル基、グリシドキシ基、メタクリル基を含む炭化水素基
ｎ：１〜３の整数
で表されるものが挙げられる。例えばビニルトリメトキシシラン，ビニルトリエトキシシラン，γ−メタクリルオキシプロピルトリメトキシシラン，ビニルトリアセトキシシラン，メチルトリメトキシシラン，メチルトリエトキシシラン，イソブチルトリメトキシシラン，ジメチルジメトキシシラン，ジメチルジエトキシシラン，トリメチルメトキシシラン，ヒドロキシプロピルトリメトキシシラン，フェニルトリメトキシシラン，ｎ−ヘキサデシルトリメトキシシラン，ｎ−オクタデシルトリメトキシシラン等を挙げることができる。
【００７４】
より好ましくは、
Ｃ_ａＨ_２ａ＋１−Ｓｉ（ＯＣ_ｂＨ_２ｂ＋１）_３
ａ＝４〜１２、ｂ＝１〜３
である。ここで、一般式におけるａが４より小さいと、処理は容易となるが疎水性が十分に達成できない。またａが１２より大きいと疎水性は十分になるが、粒子同士の合一が多くなり、流動性付与能が低下してしまう。ｂは３より大きいと反応性が低下して疎水化が十分に行われなくなってしまう。したがって上記一般式におけるａは４〜１２、好ましくは４〜８、ｂは１〜３、好ましくは１〜２が良い。
【００７５】
窒素元素を含むシランカップリング剤としては、反応制御のしやすさといったハンドリング性の見地から、また、帯電安定性の観点からヘキサメチルジシラザンが好ましい。
【００７６】
その処理量は１００質量部に対して１〜５０質量部、粒子合一させずに均一に処理するためには３〜４０質量部とするのが好ましい。
【００７７】
本発明におけるシリカ微粒子に関しては、上記疎水化処理をしたシリカにさらにオイル処理を行う。オイルとしては、ジメチルポリシロキサン、メチルハイドロジェンポリシロキサン等のシリコーンオイル、パラフィン、ミネラルオイル等が使用できるが、なかでも環境安定性に優れたジメチルポリシロキサンが好適である。
【００７８】
シリカ微粒子は、トナー母体１００質量部に対して、０．０５〜２．５質量部までの添加量が好ましい使用範囲である。
【００７９】
本発明のトナーにおいては、実質的な悪影響を与えない範囲内で更に他の添加剤、例えばポリフッ化エチレン粉末、ステアリン酸亜鉛粉末、ポリフッ化ビニリデン粉末の如き滑剤粉末；酸化セリウム粉末、炭化硅素粉末、チタン酸ストロンチウム粉末の如き研磨剤、酸化アルミニウム粉末の如きケーキング防止剤、あるいは例えばカーボンブラック粉末、酸化亜鉛粉末、酸化スズ粉末の如き導電性付与剤、また、逆極性の有機微粒子及び無機微粒子を現像性向上剤として少量用いることもできる。
【００８０】
本発明が適用可能な画像形成方法を添付図面を参照しながら以下に説明する。
【００８１】
図１の現像器４は、二成分接触現像装置（二成分磁気ブラシ現像装置）であり、マグネットローラを内包した現像スリーブ４１上にキャリアとトナーからなる現像剤を保持している。現像スリーブ４１には所定間隙を有して、現像剤規制ブレード４２が設けられ、現像スリーブ４１の矢印Ｃ方向に回転に伴い、現像スリーブ４１上に現像剤薄層を形成する。現像スリーブ４１は、感光ドラム１と所定間隙を有するように配置され、現像時においては、現像スリーブ４１上に形成された現像剤薄層が、感光ドラム１に対して接触する状態で現像できるように設定されている。現像器４内には、現像剤撹拌用の撹拌スクリュー４３、４４があり、スリーブ回転と同期して回転し、補給されたトナーとキャリアを撹拌しトナーに所定のトリボを与える機能を有している。現像剤供給ユニット５内には、トナー補給スクリュー５１があり、回転数（回転時間）によりトナー補給量を制御している。
【００８２】
図２は現像器４を上方から見た図であり、現像剤の循環状態と、長手配置を示している。スクリュー４３、４４の回転に伴い矢印方向に現像剤は循環する。現像器４のスクリュー４４の上流側壁面には、現像剤の透磁率変化を検出して現像剤中のトナー濃度を検知するセンサー４４を設けられており、そのセンサー４４のやや下流側にトナー補給開口が設けられている。現像動作を行った後に現像剤がセンサー４４部に運ばれここでトナー濃度を検知し、その検知結果に応じて現像剤中のトナー濃度を一定に維持するために、適宜現像剤供給ユニット（以下Ｔ−ＣＲＧ）５から現像器４の開口４６を通してトナー補給が行われる。補給されたトナーは矢印方向にスクリュー４４により搬送され、キャリアと混ざり合い適度なトリボを付与された後にスリーブ４１近傍に運ばれ、現像スリーブ４１上で薄層形成され現像に供される。
【００８３】
図３に示すカラーレーザープリンタは、複数個のプロセスカートリッジ７を有し、一旦第２の画像担持体である中間転写ベルト８に連続的に多重転写し、フルカラープリント画像を得る４連ドラム方式（インライン）プリンタである。図３において無端状の中間転写ベルト８が、駆動ローラ８ａ、テンションローラ８ｂ及び２次転写対向ローラ８ｃに懸架され、図中矢印の方向に回転している。
【００８４】
プロセスカートリッジ（以下Ｐ−ＣＲＧ）７は、上記中間転写ベルト８に直列に各色に対応し４本配置されている。
【００８５】
以下、Ｐ−ＣＲＧ７について説明する。
【００８６】
イエロートナーを現像するＰ−ＣＲＧ７内に配置される、感光ドラム１はその回転過程で、１次帯電ローラ２により所定の極性・電位に一様に帯電処理され、次いで不図示の画像露光手段（カラー原稿画像の色分解・結像露光光学系、画像情報の時系列電気デジタル画素信号に対応して変調されたレーザビームを出力するレーザスキャンによる走査露光系等）による画像露光３を受けることにより目的のカラー画像の第１の色成分像（イエロー成分像）に対応した静電潜像が形成される。
【００８７】
次いで、その静電潜像が第１現像器４（イエロー現像器）により第１色であるイエロートナーにより現像される。感光ドラム１上に形成されたイエロー画像は、中間転写ベルト８との１次転写ニップ部へ進入する。転写ニップ部では中間転写ベルト８の裏側にローラー状の電圧印加部材９を接触当接させている。電圧印加部材９には各ポートで独立にバイアス印加可能とするため、１次転写バイアス源９ａ〜９ｄを有している。中間転写ベルト８は１色目のポートでまずイエローを転写し、次いで先述した同様の工程を経た、各色に対応する感光ドラム１より順次マゼンタ、シアン、ブラックの各色を各ポートで多重転写する。中間転写ベルト８上で形成された４色フルカラー画像は、次いで２次転写ローラー１０により、転写材Ｐに一括転写され、不図示の定着装置によって溶融定着されカラープリント画像を得る。
【００８８】
図４は、本発明に用い得る接触非磁性一成分現像方式のプロセスカートリッジの概略図である。カートリッジ４０はトナー４２を収容しており、感光体１と接触して矢印方向に回転するトナー担持体４を具備する。また、感光体１は、図示しない接触帯電手段により帯電される。さらに、トナー量規制及び帯電付与のための現像ブレード４３，トナー４２をトナー担持体４に付着させ、かつトナー担持体４との摩擦でトナーヘの帯電付与を行うため矢印方向に回転する塗布ローラ４１も備えている。
【００８９】
【実施例】
以下、本発明を実施例により具体的に説明するが、これは、本発明を何ら限定するものではない。なお、以下の配合における部数は、特に説明のない場合は質量部である。
【００９０】
（トナーの製造例１）
下記のようにして、水系分散媒及び重合性単量体組成物を夫々調製した。
【００９１】
水系分散媒の調製
内容積２００リットルの容器中で、下記の成分を混合し、６０℃に加温した後、高速回転剪断撹拌機を用いて回転数５５ｓ^−１で撹拌した。
・水　　　　　　　　　　　　　　　　　　　　　　　　　　　　　９５０部
・０．１モル／リットル−Ｎａ３ＰＯ４水溶液　　　　　　　　　　４５０部
次に、容器内を窒素置換すると共に、これに１．０モル／リットルのＣａＣｌ_２水溶液６８部を添加して反応させ、リン酸カルシウム塩の微粒子を含む水系分散媒を得た。
【００９２】
重合性単量体組成物の調製
・スチレン　　　　　　　　　　　　　　　　　　　　　　　　　　１００部
・ｎ−ブチルアクリレート　　　　　　　　　　　　　　　　　　　　２０部
・ジビニルベンゼン　　　　　　　　　　　　　　　　　　　　　　０．３部
・着色剤（Ｃ．Ｉ．ピグメントイエロー１８０）　　　　　　　　　　　６部
・ジ‐ｔ−ブチルサリチル酸金属化合物　　　　　　　　　　　　　　　２部
・ポリエステル樹脂（酸価２０ｍｇＫＯＨ／ｇ）　　　　　　　　　　１５部
・エステル系ワックス（融点６０℃）　　　　　　　　　　　　　　　２０部
上記した成分のうち、ポリエステル樹脂およびエステルワックスを除いた各成分を混合し、アトライター（三井三池工業（株）製）を用い３時間分散させた後、ポリエステル樹脂およびエステルワックスを加えて６０℃に加温して１時間混合し、重合性単量体組成物とした。
【００９３】
上記で調製した水系分散媒が入っている高速回転剪断撹拌機の回転数を５５ｓ^−１とし、この中に、上記で調製した重合性単量体組成物を投入して造粒を開始した。造粒開始３分後、２，２’−アゾビス（２，４−ジメチルバレロニトリル）７部を、スチレン３０部に溶解したものを添加し、さらに１２分間造粒を続けた。１５分間の造粒後、プロペラ撹拌羽根を備えた撹拌機の容器内に移し、回転数を０．８３ｓ^−１回転にし、内温６２℃で反応を継続させた。６時間後、反応温度を８０℃に昇温し、加熱撹拌を５時間継続して重合を完了した。重合反応終了後、減圧下で残存モノマーを留去し、冷却後、希塩酸を添加して分散剤を溶解し、固液分離、水洗、ろ過、乾燥することによりイエロートナー粒子を得た。得られたトナーの諸物性を、表１に示す。重量平均粒径は、コールターカウンタＴＡ−ＩＩ型によって求めた。
【００９４】
（トナーの製造例２）
トナーの製造例１において、着色剤をＣ．Ｉ．ピグメントレッド１５０に変更した以外は、トナーの製造例１と同様にしてマゼンタトナー粒子を製造した。得られたトナーの諸物性を、表１に示す。
【００９５】
（トナーの製造例３）
トナーの製造例１において、着色剤をＣ．Ｉ．ピグメントブルー１５：３に変更した以外は、トナーの製造例１と同様にしてシアントナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例３の欄に示す。
【００９６】
（トナーの製造例４）
トナーの製造例１において、高速回転剪断撹拌機の造粒開始時の回転数を４５ｓ^−１とし、着色剤をカーボンブラックに変更し、その添加量を１０部とした以外は、トナーの製造例１と同様にしてブラックトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例４の欄に示す。
【００９７】
（トナーの製造例５）
トナーの製造例１において、ポリエステル樹脂を酸価０．５ｍｇＫＯＨ／ｇのエポキシ樹脂に変更した以外は、トナーの製造例１と同様にしてイエロートナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例５の欄に示す。
【００９８】
（トナーの製造例６）
トナーの製造例２において、ポリエステル樹脂を酸価０．５ｍｇＫＯＨ／ｇのエポキシ樹脂に変更した以外は、トナーの製造例２と同様にしてマゼンタトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例６の欄に示す。
【００９９】
（トナーの製造例７）
トナーの製造例３において、ポリエステル樹脂を酸価０．５ｍｇＫＯＨ／ｇのエポキシ樹脂に変更した以外は、トナーの製造例３と同様にしてシアントナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例７の欄に示す。
【０１００】
（トナーの製造例８）
トナーの製造例４において、ポリエステル樹脂を酸価０．５ｍｇＫＯＨ／ｇのエポキシ樹脂に変更した以外は、トナーの製造例４と同様にしてブラックトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例８の欄に示す。
【０１０１】
（トナーの製造例９）
トナーの製造例１において、ポリエステル樹脂を酸価４０ｍｇＫＯＨ／ｇのもの変更した以外は、トナーの製造例１と同様にしてイエロートナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例９の欄に示す。
【０１０２】
（トナーの製造例１０）
トナーの製造例２において、ポリエステル樹脂を酸価４０ｍｇＫＯＨ／ｇのもの変更した以外は、トナーの製造例２と同様にしてマゼンタトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例１０の欄に示す。
【０１０３】
（トナーの製造例１１）
トナーの製造例３において、ポリエステル樹脂を酸価４０ｍｇＫＯＨ／ｇ　のもの変更した以外は、トナーの製造例３と同様にしてシアントナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例１１の欄に示す。
【０１０４】
（トナーの製造例１２）
トナーの製造例４において、ポリエステル樹脂を酸価４０ｍｇＫＯＨ／ｇのもの変更した以外は、トナーの製造例４と同様にしてブラックトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例１２の欄に示す。
【０１０５】
（トナーの製造例１３）
・スチレン−ｎブチルアクリレート共重合体　　　　　　　　　　　１００部
・Ｃ．Ｉ．ピグメントイエロー１８０　　　　　　　　　　　　　　　　６部
・ジ−ｔｅｒｔ−ブチルサリチル酸金属化合物　　　　　　　　　　　　４部
・エステルワックス　　　　　　　　　　　　　　　　　　　　　　　　２部
溶融混練し、冷却後ハンマーミルを用いて約１〜２ｍｍ程度に粗粉砕し、次いでエアージェット方式による微粉砕機で微粉砕した。さらに分級してイエロートナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例１３の欄に示す。
【０１０６】
（トナーの製造例１４）
トナーの製造例１において、着色剤をＣ．Ｉ．ピグメントレッド１５０に変更した以外は、トナーの製造例１３と同様にしてマゼンタトナー粒子を製造した。得られたトナーの諸物性を、得られたトナーの諸物性を、表１中トナーの製造例１４の欄に示す。
【０１０７】
（トナーの製造例１５）
トナーの製造例１において、着色剤をＣ．Ｉ．ピグメントブルー１５：３に変更した以外は、トナーの製造例１３と同様にしてシアントナー粒子を製造した。得られたトナーの諸物性を、得られたトナーの諸物性を、表１中トナーの製造例１５の欄に示す。
【０１０８】
（トナーの製造例１６）
トナーの製造例１において、着色剤をカーボンブラックに変更し、その添加量を１０部とし、微粉砕の粉砕力を５％弱めた以外は、トナーの製造例１３と同様にしてブラックトナー粒子を製造した。得られたトナーの諸物性を、表１中トナーの製造例１６の欄に示す。
【０１０９】
（キャリアの製造例）
・フェノール　　　　　　　　　　　　　　　　　　　　　　　　　７．５部
・ホルマリン溶液　　　　　　　　　　　　　　　　　　　　　１１．２５部
（ホルムアルデヒド約４０％、メタノール約１０％、残りは水）
・γ−グリシドキシプロピルトリメトキシシラン１．０質量％で親油化処理した
マグネタイト微粒子　　　　　　　　　　　　　　　　　　　　　　　５３部
（平均粒径０．２４μｍ、比抵抗５×１０^５Ω・ｃｍ）
・γ−グリシドキシプロピルトリメトキシシラン１．０質量％で親油化処理した
α−Ｆｅ_２Ｏ_３微粒子　　　　　　　　　　　　　　　　　　　　　　　３５部
（平均粒径０．６０μｍ、比抵抗２×１０^９Ω・ｃｍ）
ここで用いたマグネタイト及びα−Ｆｅ_２Ｏ_３の親油化処理は、マグネタイト９９部及びα−Ｆｅ_２Ｏ_３９９部のそれぞれに対して１．０部のγ−グリシドキシプロピルトリメトキシシランを加え、ヘンシェルミキサー内で１００℃で３０分間、予備混合撹拌することによって行なった。
【０１１０】
上記材料および水１１部を４０℃に保ちながら、１時間混合を行った。このスラリーに塩基性触媒として２８質量％アンモニア水２．０部、および水１１部をフラスコに入れ、撹拌・混合しながら４０分間で８５℃まで昇温・保持し、３時間反応させ、フェノール樹脂を生成し硬化させた。その後、３０℃まで冷却し、１００部の水を添加した後、上澄み液を除去し、沈殿物を水洗し、風乾した。次いで、これを減圧下（５ｍｍＨｇ以下）に１８０℃で乾燥して、フェノール樹脂を結着樹脂としたマグネタイト微粒子含有球状の磁性キャリアコア粒子を得た。
【０１１１】
この粒子を６０メッシュ及び１００メッシュの篩によって、粗大粒子の除去を行ない、次いでコアンダ効果を利用した多分割風力分級機（エッポジェットラボＥＪ−Ｌ−３、日鉄鉱業社製）を使用して微粉除去及び粗粉除去をおこない、体積平均５０％粒径３５μｍのキャリアコア粒子を得た。得られたキャリアコアは、比抵抗が２．２×１０^１２Ω・ｃｍであり、水分量が．０．１５質量％であった。
【０１１２】
得られたキャリアコア粒子をコーター内に投入し、加湿窒素を流入させ水分量０．３質量％に調整した。その後、トルエン溶媒を用いて希釈したγ−アミノプロピルトリメトキシシラン３質量％を剪断応力を連続して印加しつつ、コア表面に処理した。またその際、４０℃，１３．３ｋＰａ（１００ｔｏｒｒ），乾燥窒素気流下で溶媒を揮発させながら行なった。引き続き、置換基がすべてメチル基であるストレートシリコーン樹脂０．５質量％及び、γ−アミノプロピルトリメトキシシラン０．０１５質量％の混合物をトルエンを溶媒として被覆した。その際、４０℃，６６．５ｋＰａ（５００ｔｏｒｒ），乾燥窒素気流下で溶媒を揮発させながら行なった。
【０１１３】
さらに、この磁性コートキャリアを１４０℃で焼き付け、１００メッシュの篩で、凝集した粗大粒子をカットし、次いで多分割風力分級機で微粉及び粗粉を除去して粒度分布を調整した。その後２３℃，６０％内で保たれたホッパー内で１００時間調湿して磁性体分散型樹脂キャリアを得た。
【０１１４】
〔実施例１〕
トナーの製造例１、トナーの製造例２、トナーの製造例３およびトナーの製造例４において得られたイエロー、マゼンタ、シアンおよびブラックトナー母体それぞれについて、シリカ微粒子をトナー粒子１００部に対して表２に示した外添処方１によって、ヘンシェルミキサー１０Ｂ（三井三池化工機社製）において、回転数３０００ｒｐｍ、撹拌時間４分間の条件下で混合し、負摩擦帯電性のカラートナーを得た。このとき、加える各外添剤は、それぞれ別個にトナーに投入するのではなく、使用するすべての外添剤を１つの容器に一度投入した後に、トナー母体を投入した状態のヘンシェルミキサーに加えた。
【０１１５】
このトナー８部に対し、キャリアの製造例で作製された磁性体分散型樹脂キャリア９２部を混合して現像剤を調製した。
【０１１６】
以上のトナー及び現像剤を用いて、１５℃／１０％ＲＨの低温低湿環境、２０℃５５％中温中湿環境および３０℃／８０％ＲＨの高温高湿環境下において、以下の評価方法に基づき、図３に示したフルカラー画像形成装置によって、プロセススピード１９０ｍｍ／ｓ、プリント速度をＡ４横４３枚／分、現像剤担持体の回転速度はプロセススピードの１５０％、紙面積に対するプリント比率４％での、７５ｇ／ｍ^２Ａ４普通紙７万枚連続プリント試験を行った。その結果、いずれの評価においても良好な結果が得られた。評価結果を表３に示す。また、シリカ微粒子の種類は表７に示す。
【０１１７】
なお、すべての実施例について、以下の評価方法に基づいたプリント初期の評価結果は、すべて良好であった。
【０１１８】
＜トナー凝集度測定＞
パウダーテスター（ホソカワミクロン社製）の振動篩機を用い、振動台に４００ｍｅｓｈ（目開き３７μｍ）、２００ｍｅｓｈ（目開き７４μｍ）、１００ｍｅｓｈ（目開き１４７μｍ）の篩を目開の狭い順に重なる様に、即ち、１００ｍｅｓｈが最上位となる様に、４００ｍｅｓｈ、２００ｍｅｓｈ、１００ｍｅｓｈの篩の順に重ねてセットする。このセットした１００ｍｅｓｈの篩上に試料を加え、振動台の振幅が０．６±０．０１ｍｍの範囲で１５秒間振動を加える。その後、各篩上に残った試料の質量を測定し、下式に基づき凝集度を得る。凝集度の値が小さい程、トナーの流動性は高い。
【０１１９】
【数５】

【０１２０】
＜評価方法＞
（１）二次色およびブラック全ベタがさつき
７万枚連続プリント試験終了後、試験環境において十分調湿されたＡ３サイズの７５ｇ／ｍ^２紙において、グリーン、レッド、ブルーの各二次色およびブラックの全べた画像をプリントし、以下の基準から目視評価を行った。
Ａ：均一な全べた画像がプリントされる
Ｂ：光にかざして見ると、ややがさついた不均一なべた画像であることが確認できる
Ｃ：ややがさついた不均一なべた画像である
Ｄ：がさついた不均一なべた画像である
【０１２１】
（２）ハーフトーンがさつき
７万枚連続プリント試験終了後、試験環境において十分調湿されたＡ３サイズの７５ｇ／ｍ^２紙において、イエロー、マゼンタ、シアン、ブラック単色およびレッド、グリーン、ブルーの二次色ハーフトーン画像をプリントし、以下の基準から目視評価を行った。
Ａ：均一なハーフトーン画像がプリントされる
Ｂ：光にかざして見ると、ややがさついた不均一なハーフトーン画像であることが確認できる
Ｃ：ややがさついた不均一なハーフトーン画像である
Ｄ：がさついた不均一なハーフトーン画像である
【０１２２】
（３）トナー感光ドラム融着
７万枚連続プリント試験終了後、使用した感光ドラムに対して、エアブローにてドラム上に残っている弱い付着物を取り除いた後にマイクロスコープ観察を行い、以下の基準で評価を行った。
Ａ：ドラム中央および画像形成領域の両端部からそれぞれ約５ｃｍの位置において、５０倍のマイクロスコープ観察を行ったとき、トナー融着が確認されない
Ｂ：ドラム中央および画像形成領域の両端部からそれぞれ約５ｃｍの位置において、５０倍のマイクロスコープ観察を行ったとき、トナー融着が確認されるが、付着起因の画像抜けは発生しない。
Ｃ：マイクロスコープ観察を行ったとき、トナー融着が確認され、融着起因の画像抜けがドラム１周当たり３個以下。
Ｄ：マイクロスコープ観察を行ったとき、トナー融着が確認され、融着起因の画像抜けがドラム１周当たり４個以上。
【０１２３】
（４）帯電部材汚れ
７万枚連続プリント試験終了後、試験環境において十分調湿されたＡ３サイズの７５ｇ／ｍ^２紙において、各色の全白画像をプリントし、以下の基準から目視評価を行った。
Ａ：部分的なプリントが確認されない。帯電部材にも局所的な汚れが見られない。
Ｂ：部分的なプリントが確認されない。帯電部材には局所的な汚れが若干見られる。使用した帯電部材を新品の帯電部材と交換すると、それが消失する
Ｃ：極薄い部分的なプリントが見られる。帯電部材には局所的な汚れが見られる。使用した帯電部材を新品の帯電部材と交換すると、それが消失する
Ｄ：部分的なプリントが確認される。帯電部材には局所的なひどい汚れが見られる。使用した帯電部材を新品の帯電部材と交換すると、それが消失する
【０１２４】
（５）現像剤耐久性
初期及び７万枚連続プリント試験終了後において、現像剤担持体上の単位面積当たりの剤量（Ｍ／Ｓ）を測定した。
【０１２５】
（６）環境安定性
初期及び７万枚連続プリント試験終了後において、現像剤担持体上のトナー帯電量をブローオフ法に基づいて測定した。
【０１２６】
〔実施例２〜９〕
表２に示した外添処方に従い、実施例１と同様の検討を行った。評価結果を表３又は表４に示す。
【０１２７】
〔実施例１０〕
実施例１において、イエロー、マゼンタ、シアンおよびブラックトナー母体を、トナーの製造例５、トナーの製造例６、トナーの製造例７およびトナーの製造例８で得られた物に変更する以外は、実施例１と同様の検討を行った。評価結果を表４に示す。
【０１２８】
〔実施例１１〕
実施例１において、イエロー、マゼンタ、シアンおよびブラックトナー母体を、トナーの製造例９、トナーの製造例１０、トナーの製造例１１およびトナーの製造例１２で得られた物に変更する以外は、実施例１と同様の検討を行った。評価結果を表４に示す。
【０１２９】
〔実施例１２〕
実施例１において、イエロー、マゼンタ、シアンおよびブラックトナー母体を、トナーの製造例１３、トナーの製造例１４、トナーの製造例１５およびトナーの製造例１６で得られた物に変更する以外は、実施例１と同様の検討を行った。評価結果を表４に示す。
【０１３０】
〔実施例１３〕
実施例１で使用したトナーおよび現像剤を用い、図１、図２および図３に示した画像形成装置において、オートリフレッシュ現像方式が適用できるように機構を変更し、Ｔ−ＣＲＧ中の補給用現像剤には１５質量％の磁性キャリアを含有させ、１５℃／１０％ＲＨの低温低湿環境および２０℃／５５％ＲＨの中温中湿環境および３０℃／８０％ＲＨの高温高湿環境下において、プロセススピード２３０ｍｍ／ｓ、プリント速度をＡ４横５０枚／分、現像剤担持体の回転速度はプロセススピードの１５０％、紙面積に対するプリント比率４％での、７５ｇ／ｍ^２Ａ４普通紙７万枚連続プリント試験を行った。その結果、各環境いずれも、二次色および単色の全べた、ハーフトーンとも耐久終了後においてがさつきの無い良好な画像を維持し、帯電部材汚染、感光ドラム汚染は観察されなかった。さらにその後、プリント比率１％の画像を１０００枚印字した後にプリント比率１００％の画像を２０枚印字させ、その直後に各色ごとに単色全べた画像を出力し、前述の普通紙５万枚連続プリント試験直後の単色全べた画像中央の画像濃度（反射濃度計ＲＤ９１８（マクベス社製）での測定）との差を調べた。その結果、各環境各色いずれもその差は０．１以内であった。
【０１３１】
〔比較例１乃至１０〕
表２に示した外添処方に従い、実施例１と同様の検討を行った。評価結果を表５又は６に示す。なお、比較例８〜１０においては、全環境全色において、初期画像から若干のハーフトーンがさつきが観察された。
【０１３２】
〔参考例１〕
すべての実施例および比較例において、用いた画像形成装置について、プロセススピード１００ｍｍ／ｓ、帯電Ｖｐｐ＝１２００Ｖ、プリント速度をＡ４横１７枚／分に変更して、紙面積に対するプリント比率４％での５万枚通紙時点での全べたがさつき、ハーフトーンがさつき、感光ドラム汚染および帯電部材汚れの評価を各環境で行った。その結果すべての実施例および比較例について、各色とも評価項目すべてがＡランクであった。
【０１３３】
さらに続けて２万枚通紙したところ、すべての比較例について、表５と６の本検討結果表と比べて、全べたがさつきおよびハーフトーンがさつきについて、２ランク良化の結果を示した。感光ドラム汚染および帯電部材汚れはすべてＡランクであった。すべての実施例は、この条件の検討ではすべてＡランクだった。
【０１３４】
比較例８〜１０においては、初期画像のハーフトーンがさつきは各環境ともランクＡであった。
【０１３５】
【表１】

【０１３６】
【表２】

【０１３７】
【表３】

【０１３８】
【表４】

【０１３９】
【表５】

【０１４０】
【表６】

【０１４１】
【表７】

【０１４２】
【発明の効果】
高速、高画質、高耐久、低環境負荷、および高環境安定性を満足するトナーおよび画像形成方法を提供することができる。
【図面の簡単な説明】
【図１】本発明が適用可能な画像形成方法の説明図である。
【図２】図１の現像器を上方から見た図である。
【図３】カラーレーザープリンタの説明図である。
【符号の説明】
１　感光ドラム
２　帯電ローラ
３　レーザ光
４　現像装置
５　現像剤供給ユニット（補給用トナーキット）
６　クリーナ
７　プロセスカートリッジ（プロセストナーキット）
８　中間転写ベルト
９　１次転写電極
１０　２次転写ローラ
１１　中間転写ベルトクリーナ
１２　レジストローラ
２０　強誘電体不揮発メモリ（ＦｅＲＡＭ）
４１　現像スリーブ
４２　ブレード
４３および４４　現像剤撹拌スクリュー
４５　トナー濃度検知センサー
４６　現像器補給開口
５１　スクリュー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to toner and image formation used in an image forming apparatus such as an electrophotographic system or an electrostatic recording system in which a developer is attached to a latent image formed on an image carrier for visualization. It is about the method.
[0002]
[Prior art]
Conventionally, as an electrophotographic method, many methods are known as described in Patent Document 1 and Patent Document 2, but in general, an electrostatic charge image carrier is a photoconductor using a photoconductive substance, and various methods are available. An electric latent image is formed on the photosensitive member by means, and then the latent image is developed with toner to form a visible image. If necessary, the toner image is transferred to a transfer material such as paper, and then heat / pressure is applied. The toner image is fixed on the transfer material by, for example, to obtain a copy. Further, the toner remaining without being transferred onto the photoreceptor is cleaned or recovered by various methods and reused, and the above-described steps are repeated.
[0003]
In recent years, full-color image forming apparatuses using electrophotography have been actively proposed, and needs are increasing. Basically, it is a combination of yellow toner, magenta toner, cyan toner and, if necessary, black toner, and is described in Patent Document 3 and the like. In a full-color copy image, three colors or four colors of toner including black are sequentially superimposed on the transfer paper, and development characteristics, charging stability, and transfer characteristics are important factors that determine image quality. . As image forming apparatuses such as color copiers and color laser printers become widespread, their applications have been expanded to various types, and demands for image quality and productivity have become severe. Therefore, further improvement of these factors is the most important issue in development. It must also be achieved in a way that does not burden the environment.
[0004]
For example, as means for preventing toner deterioration, it has been proposed to add two or more types of external additives having different particle diameters described in Patent Documents 4 to 7 and the like. However, even if these proposals are directly applied to a color image forming method, it is difficult to meet the needs for high speed, high image quality, and high durability. This is because a color image is formed by superimposing a plurality of colors, so that slight toner deterioration or member contamination tends to adversely affect the quality. In addition, from the viewpoint of reducing environmental impact, various proposals such as contact charging and contact transfer that suppress the generation of ozone have been made. However, it is difficult to simply apply to color image formation as it is, and conversely a complicated control method. Often there is a need to use. For example, when the process speed is increased, it may be necessary to increase the Vpp of the charging AC in order to maintain the charging uniformity of the electrostatic charge image bearing member. Action is required.
[0005]
[Patent Document 1]
Japanese Patent Publication No.42-23910
[Patent Document 2]
Japanese Patent Publication No.43-24748
[Patent Document 3]
Japanese Patent Publication No.53-47176
[Patent Document 4]
Japanese Examined Patent Publication No. 2-45188
[Patent Document 5]
JP-A-8-36316
[Patent Document 6]
JP-A-11-095485
[Patent Document 7]
JP-A-11-272008
[0006]
[Problems to be solved by the invention]
In view of the above situation, the present invention provides a toner and an image forming method having high speed, high image quality, high durability, and excellent environmental stability in a color electrophotographic apparatus having a contact charging and contact transfer system. Objective.
[0007]
[Means for Solving the Problems]
The above object is achieved by the present invention described below.
[0008]
That is, an electrostatic charge image carrier for carrying an electrostatic charge image is charged, an electrostatic charge image is formed on the charged electrostatic charge image carrier, and the electrostatic image is developed with toner included in the developing means to form a toner image. Used in an image forming method in which a toner image on an electrostatic charge image carrier is transferred to a transfer material with or without an intermediate transfer member, and the toner image on the transfer material is fixed by a fixing unit Because
Charging is performed by a member in contact with the electrostatic image carrier, transfer is performed by a member in contact with a transfer member, and a toner image is toner used in an image forming method fixed by a thermal fixing unit,
The toner is externally added with at least two types of surface-treated silica fine particles having different BET specific surface areas, the silica fine particles (a) having the largest BET specific surface area, and then the silica fine particles (b) having the largest BET specific surface area. The difference in BET specific surface area is 30m²/ G or more, both the silica fine particles (a) and (b) are treated with a silane coupling agent, and both are treated with a silicone oil, and the amount of oil treatment is 100 masses of the untreated silica fine particle matrix. 2 parts by weight to 40 parts by weight with respect to parts, and the BET specific surface area of the untreated silica fine particle matrix is 1 m.²The amount of oil treated per unit of the silica fine particles (b) is 0.7 to 90 times that of the silica fine particles (a), and (b) with respect to 100 parts by mass of the toner base particles (a) with respect to the added mass parts. This is achieved by a toner and an image forming method characterized in that the added mass part is 0.2 to 5.0 times.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, an electrostatic charge image carrier for carrying an electrostatic charge image is charged, an electrostatic charge image is formed on the charged electrostatic charge image carrier, and the electrostatic charge image is developed with toner included in the developing means. A general electrophotographic process in which a toner image is formed, a toner image on an electrostatic charge image carrier is transferred to a transfer material with or without an intermediate transfer member, and the toner image on the transfer material is fixed by a fixing unit. In the image forming method in which charging is performed by a member in contact with the electrostatic image bearing member and transfer is performed by a member in contact with the transfer member, at least two types of surface treatments having different BET specific surface areas were applied as toners. The difference in BET specific surface area between silica fine particles (a) having the largest BET specific surface area and silica fine particles (b) having the next largest BET specific surface area is 30 m.²/ G or more, both the silica fine particles (a) and (b) are treated with a silane coupling agent, and both are treated with a silicone oil, and the amount of oil treatment is 100 masses of the untreated silica fine particle matrix. 2 parts by weight to 40 parts by weight with respect to parts, and the BET specific surface area of the untreated silica fine particle matrix is 1 m.²The amount of oil treated per unit of the silica fine particles (b) is 0.7 to 90 times that of the silica fine particles (a), and (b) with respect to 100 parts by mass of the toner base particles (a) with respect to the added mass parts. By using a toner characterized in that the added mass part of the toner is 0.2 to 5.0 times, it is possible to effectively suppress member deterioration such as toner deterioration or charging member contamination due to high speed and large number of prints. In addition, transfer efficiency and solid image uniformity can be improved.
[0010]
By using two or more types of silica with different BET specific surface areas, silica with a small BET acts as spacer particles to prevent deterioration, and the silica with a large BET has the effect of charge control and fluidity imparting to the toner. Can do. However, when applying such toners to contact charging and contact transfer system processes, and when applying them to high-speed printers and copiers, contamination is maintained while preventing toner deterioration and improving transfer characteristics. It is necessary to highly control such harmful effects. The difference between the BET specific surface area of the silica fine particles (a) having the largest BET specific surface area and the silica fine particles (b) having the next largest BET specific surface area is 30 m.²/ G or more, both the silica fine particles (a) and (b) are treated with a silane coupling agent, and both are treated with a silicone oil, and the amount of oil treatment is 100 masses of the untreated silica fine particle matrix. 2 parts by weight to 40 parts by weight with respect to parts, and the BET specific surface area of the untreated silica fine particle matrix is 1 m.²The amount of oil treated per unit of the silica fine particles (b) is 0.7 to 90 times that of the silica fine particles (a), and (b) with respect to 100 parts by mass of the toner base particles (a) with respect to the added mass parts. This is achieved by externally adding two or more kinds of silica fine particles having an added mass part of 0.2 to 5.0 times to the toner.
[0011]
By both performing silane coupling treatment, environmental stability and high durability are satisfied, and by applying oil treatment together, member resistance is achieved by the release action of oil. In the case of only the silane coupling process, the contamination at the contact portion becomes conspicuous as the process speed is increased in order to realize high-speed printing. Alternatively, in both cases where only oil processing is performed, environmental fluctuations due to deterioration increase as the load on the developer increases. It seems that high durability was achieved by providing a hydrophobic lower layer in the oil lower layer. It has been clarified by examination that silica with a large particle size and a small BET is particularly conspicuous, but when each process operates at high speed, the adhesion of the member becomes severe even with silica fine particles with a large BET. Therefore, it is necessary to perform oil treatment together. As a further excellent effect, it has been discovered that when both the silica fine particles (a) and (b) are treated with a silane coupling agent and both are treated with a silicone oil, the solid image can be transferred. did. In particular, when transferring a solid image of a secondary color or more in color, that is, an image in which two or more colors of toner are superimposed, the transfer efficiency is improved, the image becomes uniform, and a high-quality color image can be created. I found out that I can do it. Since this is a phenomenon observed from the beginning, it is considered to be a new effect when both the silica fine particles (a) and (b) are treated with the silane coupling agent and both are treated with the silicone oil.
[0012]
Since the silica fine particles (a) and (b) separate the function as spacer particles and the function of imparting fluidity, the difference in BET specific surface area is 30 m.²/ G or more is necessary.
[0013]
The oil treatment amount is appropriately 2 to 40 parts by mass with respect to 100 parts by mass based on the untreated silica fine particle matrix. If the amount of oil treatment is too small, the mold release effect is weakened, so that contamination of members is likely to occur. On the other hand, if it is too much, on the contrary, contamination with oil occurs or transferability deteriorates.
[0014]
Further, the BET specific surface area of the untreated silica fine particle matrix is 1 m.²It is necessary to design the silica fine particles (b) to be 0.7 to 90 times the silica fine particles (a) with respect to the per-oil treatment amount. When it is less than 0.7 times, even when the oil treatment amount is in the range of 2 to 40 parts by mass, a phenomenon in which the adhesion of silica fine particles having a small BET to the contact charging member is rapidly increased is observed. . As for the charging bias, it is common to superimpose a direct current on an alternating current, but the degree of adhesion varies depending on the frequency of the alternating current and Vpp, so some electrical action on silica in the micro area causes such a phenomenon. However, the detailed mechanism is unknown. The phenomenon becomes more prominent as the process speed increases. According to the study by the present inventors, a phenomenon was observed in which the process speed suddenly became remarkable at 140 mm / s. When the ratio exceeded 90 times, a phenomenon was observed in which the toner chargeability fluctuates greatly due to continuous paper feeding. Since the difference in the amount of oil per surface between silica (a) and (b) is too great, it is expected that the physical properties of silica fine particles will increase when the load on the developer continues for a long time. . More preferably, it is 1.5 to 50 times.
[0015]
Regarding the addition amount of the silica fine particles, the addition mass of (b) to the addition mass part of (a) per 100 parts by mass of the toner base particles in order to clearly exhibit the function as spacer particles and the function of imparting fluidity, respectively. The part needs to be 0.2 to 5.0 times. If it is out of the range, the effect of one of the fine particles is buried.
[0016]
A more preferable condition for the silica fine particles is that the BET specific surface area of the silica fine particles (a) is 15 m.²/ G to 150m²/ G and the BET specific surface area of the silica fine particles (b) is 70 m.²/ G to 300m²/ G. Thereby, each silica plays a more effective role.
[0017]
The BET specific surface areas of the silica fine particles (a) and (b) described above are values in the final use form after the silane coupling treatment and the oil treatment.
[0018]
In order to further improve the charging stability, the toner preferably contains a polar resin having an acid value of 1 to 35 mgKOH / g. As the polar resin, it is particularly preferable to use a condensation compound from the viewpoint of both chargeability and fixability. Examples thereof include polyester, polycarbonate, phenol resin, epoxy resin, polyamide, and cellulose. More preferably, polyester is desired due to the variety of materials.
[0019]
Further, when the average circularity measured by the toner flow type particle image measuring apparatus is 0.950 to 1.000 and the circularity standard deviation is less than 0.040, charging stability, member contamination, and transfer efficiency. Etc. become better. In particular, the secondary transfer efficiency at a high process speed is improved, and solid and halftone images with little roughness can be output efficiently. In addition, it is preferable to use a styrene polymerized toner produced with an aqueous medium as the toner base because the high durability of the present invention is further utilized.
[0020]
It should be noted that the charging is performed by a roller in contact with the electrostatic charge image bearing member, and the transfer is performed by a roller in contact with the intermediate transfer member and a roller in contact with the transfer material. From the viewpoint of As the hardness of the charging roller, if the hardness is too low, the shape will not be stable, so it will be permanently deformed by contact with the object to be charged and the desired roller shape will not be secured, and if it is too high, it will be uniform between the object to be charged In addition to ensuring a stable charged contact portion, the micro contact property to the surface of the object to be charged is deteriorated. For this reason, the hardness of the charging roller is preferably in the range of 25 to 50 degrees in terms of Asker C hardness (Kobunshi Keiki Co., Ltd.). The charging roller is made of elastic material such as EPDM (ethylene / propylene / diene terpolymer), NBR, silicone rubber, IR, urethane and other conductive materials such as carbon black and metal oxide for resistance adjustment. A rubber material in which is dispersed or a foamed material of these is used. Note that it is also possible to adjust the resistance using an ion conductive material without dispersing the conductive substance. The contact pressure of the charging roller is preferably 5 to 300 N / m. As the transfer roller, for example, a metal cored bar having a volume resistivity of 10 is used.⁶-10⁹A structure covered with an elastic body such as EPDM, urethane rubber, CR, NBR adjusted to Ω · cm can be employed.
[0021]
Although the present invention can be applied to both one-component development and two-component development, the use of a two-component development method comprising a non-magnetic toner and a magnetic carrier is advantageous in maintaining high-speed and high-quality printing for a long period of time. It is preferable because it works. The magnetic carrier is composed of an element such as iron alone or a composite ferrite state. The magnetic carrier has a spherical shape, a flat shape, or an indeterminate shape. Furthermore, it is preferable to control the fine structure (for example, surface irregularity) of the surface state of the magnetic carrier particles. In general, a method is used in which magnetic carrier core particles are produced in advance by firing and granulating the inorganic oxide, and then coating the resin. From the viewpoint of reducing the load on the toner of the magnetic carrier, a method of obtaining a low-density dispersion carrier by kneading and classifying the inorganic oxide and the resin and further kneading the inorganic oxide and the monomer directly. A method of obtaining a true spherical magnetic carrier by suspension polymerization in an aqueous medium can also be used. In the present invention, it is particularly preferable to use a magnetic material-dispersed resin carrier prepared by mixing a magnetic inorganic oxide such as magnetite and an organic compound such as a monomer and polymerizing the mixture in an aqueous medium. This is because the spherical shape makes it difficult to damage the toner and the effect of the present invention lasts for a long time.
[0022]
The toner of the present invention is a development system comprising a two-component developer comprising a non-magnetic toner and a magnetic carrier and a replenishment developer, wherein the replenishment developer contains a magnetic carrier, It is suitable for an auto-refresh development system in which deteriorated carriers are sequentially collected and fresh carriers of replenishment developer are sequentially replenished. This is because long-term stability by the auto-refresh development method is more enhanced by the toner of the present invention. For example, even when the developer is rapidly replenished when a print with a high print ratio is made after a print with a low print ratio is continued, fluctuations in the charge amount can be controlled by suppressing toner deterioration.
[0023]
The measurement of the BET specific surface area is performed using a known apparatus such as a degassing apparatus Bacuprep 061 (manufactured by Micromesotech) or a BET measuring apparatus Gemini 2375 (manufactured by Micromesotech). The BET specific surface area in the present invention is a value of a one-point method BET specific surface area. Specifically, the procedure is as follows.
[0024]
After measuring the weight of the empty sample cell, the sample to be measured is filled so as to fall between 0.01 and 0.002 g. Further, the sample cell filled with the sample is set in the degassing apparatus, and degassing is performed at room temperature for 3 hours. After completion of degassing, the mass of the entire sample cell is measured, and the accurate mass of the sample is calculated from the difference from the empty sample cell. Next, empty sample cells are set in the balance port and analysis port of the BET measuring apparatus. A dewar bottle containing liquid nitrogen is set at a predetermined position, and P0 is measured by a saturated vapor pressure (P0) measurement command. After the P0 measurement is completed, the sample cell prepared for degassing is set in the analysis port, and after inputting the sample mass and P0, the measurement is started by the BET measurement command. After that, the BET specific surface area is automatically calculated.
[0025]
The acid value is determined as follows. Basic operation conforms to JIS-K0070.
[0026]
The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids, etc. contained in 1 g of the sample is called the acid value, and the test is conducted as follows.
[0027]
(1) Reagent
(A) Solvent ethyl ether-ethyl alcohol mixed solution (1 + 1 or 2 + 1) or benzene-ethyl alcohol mixed solution (1 + 1 or 2 + 1), these solutions are N / 10 potassium hydroxide ethyl alcohol solution using phenolphthalein as an indicator just before use. Neutralize with.
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 10 potassium hydroxide-ethyl alcohol solution Dissolve 7.0 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. The standardization is performed according to JIS K 8006 (basic matters regarding titration during the reagent content test).
(2) Operation: Weigh correctly 1 to 20 g of sample, add 100 ml of solvent and a few drops of phenolphthalein solution as an indicator, and shake well until the sample is completely dissolved. In the case of a solid sample, dissolve it by heating on a water bath. After cooling, this is titrated with an N / 10 potassium hydroxide ethyl alcohol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds.
(3) Calculation formula The acid value is calculated by the following formula.
[0028]
[Expression 1]

Where A: acid value
B: Use amount of N / 10 potassium hydroxide ethyl alcohol solution (ml)
f: Factor of N / 10 potassium hydroxide ethyl alcohol solution
S: Sample (g)
[0029]
The equivalent circle diameter, circularity, and frequency distribution of the toner in the present invention are used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow type particle image measuring device FPIA is used. -1000 type (manufactured by Toa Medical Electronics Co., Ltd.) was used for measurement, and calculation was performed using the following formula.
[0030]
[Expression 2]

[0031]
Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define.
[0032]
The circularity in the present invention is an index indicating the degree of unevenness of toner particles, and is 1.000 when the toner particles are perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated.
[0033]
In the present invention, the circle-equivalent number average diameter D1 (μm) and the particle size standard deviation SDd, which mean the average value of the particle number frequency distribution based on the number of toners, are the particle size (central value) at the dividing point i of the particle size distribution. Is di, and the frequency is fi.
[0034]
[Equation 3]

[0035]
Further, the average circularity C and the circularity standard deviation SDc, which mean the average value of the circularity frequency distribution, are the circularity (center value) at the dividing point i of the particle size distribution, ci, and the frequency is f._ciThen, it is calculated from the following equation.
[0036]
[Expression 4]

[0037]
As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a dispersion means, an ultrasonic disperser UH-50 type (manufactured by SMT Co., Ltd.) equipped with a 5φ titanium alloy chip as a vibrator is used, and subjected to a dispersion treatment for 5 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not become 40 degreeC or more.
[0038]
To measure the shape of the toner particles, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 toner particles Measure above. After the measurement, this data is used to obtain the equivalent circle diameter, circularity frequency distribution, etc. of the toner particles.
[0039]
As a method for producing the toner base of the present invention, a known production method can be used. In particular, as described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842, spherical toners that make the present invention more effective can be easily obtained. A direct toner production method using a suspension polymerization method; a soap-free polymerization method, which is soluble in monomers and directly polymerized in the presence of a water-soluble polymerization initiator to produce toner particles Production of toner particles by an emulsion polymerization method is preferred. In addition, production of an interfacial polymerization method such as a microcapsule production method, an in situ polymerization method, a coacervation method, and the like can also be mentioned. Further, there may be mentioned an interface association method in which at least one kind of fine particles are aggregated to obtain a desired toner as disclosed in JP-A-62-106473 and JP-A-63-186253. Alternatively, a method in which the toner obtained by the pulverization method is spheroidized by a mechanical impact force can be used.
[0040]
Among these, a suspension polymerization method that can easily obtain toner particles having a small particle diameter is particularly preferable. When suspension polymerization is used as a method for producing toner particles, the toner particles can be produced directly by the following production method.
[0041]
Adds a colorant, polymerization initiator, cross-linking agent, and other additives to the monomer, and contains a dispersion stabilizer that is uniformly dissolved or dispersed by a homogenizer, ultrasonic disperser, etc. Disperse in an aqueous medium using a normal stirrer, homomixer or homogenizer. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, usually 50 to 90 ° C. (preferably 55 to 85 ° C.). The temperature may be raised in the latter half of the polymerization reaction, and the pH may be changed as necessary. In the present invention, in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the aqueous medium is partially distilled off in the latter half of the reaction or after the completion of the reaction. May be. After completion of the reaction, the produced toner particles are collected by washing and filtration and dried.
[0042]
The following describes the material of the polymerization toner.
[0043]
As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer is mainly used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate , N-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.
[0044]
In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more.
[0045]
As the polymerization initiator used in the polymerization of the polymerizable monomer described above, an oil-soluble initiator and / or a water-soluble initiator is used. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumylper Kisaido, t- butyl hydroperoxide, di -t- butyl peroxide, include peroxide initiators such as cumene hydroperoxide.
[0046]
Water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloric acid Salts, sodium azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.
[0047]
In order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor or the like can be further added and used.
[0048]
Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, and barium sulfate. , Bentonite, silica, alumina, hydroxyapatite and the like. Usually, it is preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.
[0049]
As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used. These dispersants are preferably used in an amount of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.
[0050]
Other dispersion stabilizers preferably used include sparingly water-soluble metal salts of sulfuric acid, carbonic acid, phosphoric acid, pyrophosphoric acid, and polyphosphoric acid. These are acid alkali metal salts and metal halide salts under high-speed stirring in a dispersion medium. It is preferable to prepare by this reaction.
[0051]
In order to refine these dispersants, 0.001 to 0.1% by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.
[0052]
When the condensation compound is used as a toner material in the present invention, the production method includes, for example, a synthesis method by oxidation reaction, synthesis from carboxylic acid and its derivatives, ester group introduction reaction represented by Michael addition reaction, carboxylic acid It is produced by a method utilizing a dehydration condensation reaction from a compound and an alcohol compound, a reaction from an acid halide and an alcohol compound, or a transesterification reaction. The catalyst may be a general acidic or alkaline catalyst used in the esterification reaction, such as zinc acetate or a titanium compound. Thereafter, it may be highly purified by a recrystallization method, a distillation method or the like.
[0053]
A particularly preferred production method of the condensation compound is a dehydration condensation reaction from a carboxylic acid compound and an alcohol compound because of the versatility of raw materials and the ease of reaction. In this case, it is preferable that 45 to 55 mol% of all components is an alcohol component and 55 to 45 mol% is an acid component. As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, the following formula (I)
[0054]
[Chemical 1]

(Wherein R represents an ethylene or propylene group, x and y each represents an integer of 1 or more, and the average value of x + y represents 2 to 10), or the following formula (II)
[0055]
[Chemical 2]

Diols such as the diol represented by
[0056]
Divalent carboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, diphenyl-P · P′-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane Benzene dicarboxylic acids such as P · P′-dicarboxylic acid, benzophenone-4,4′-dicarboxylic acid, 1,2-diphenoxyethane-P · P′-dicarboxylic acid or anhydrides thereof; succinic acid, adipic acid, sebacin Acids, azelaic acid, glutaric acid, cyclohexanedicarboxylic acid, triethylenedicarboxylic acid, alkyldicarboxylic acids such as malonic acid or anhydrides thereof, and succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms Anhydrides such as fumaric acid, maleic acid, citraconic acid, itaconic acid Such unsaturated dicarboxylic acids or their anhydrides.
[0057]
A particularly preferred alcohol component of the condensation compound is a bisphenol derivative represented by the above formula (I), and examples of the acid component include phthalic acid, terephthalic acid, isophthalic acid or its anhydride, succinic acid, n-dodecenyl succinic acid, Alternatively, dicarboxylic acids such as anhydrides thereof, fumaric acid, maleic acid and maleic anhydride can be mentioned.
[0058]
The condensed compound can be obtained by synthesizing from a divalent dicarboxylic acid and a divalent diol. In some cases, a trivalent or higher polycarboxylic acid or polyol may be used in a small amount as long as it does not adversely affect the present invention.
[0059]
Trivalent or higher polycarboxylic acids include trimellitic acid, pyromellitic acid, cyclohexanetricarboxylic acids, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid Acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,3-dicarboxyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2 , 7,8-octanetetracarboxylic acid and their anhydrides.
[0060]
Examples of triols having a valence of 3 or more include sulfitol, 1,2,3,6-hexaneteitol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-methanetriol. Glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.
[0061]
When toner particles are directly produced in an aqueous medium, 1 to 30 parts by mass (more preferably 2 to 25 parts by mass) of a polar resin is blended with 100 parts by mass of the polymerizable monomer, and the toner It should be contained in the particles.
[0062]
Examples of the toner releasing agent used in the present invention include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, and Fischer Tropish wax, amide wax, ketone wax, higher fatty acid, long chain alcohol, ester wax, and the like. These include low softening point substances such as graft compounds and derivatives such as block compounds, and those having a sharp maximum endothermic peak in the DSC endothermic curve from which low molecular weight components have been removed are preferred. Two or more kinds of blends may be used.
[0063]
Examples of the wax preferably used include linear alkyl alcohols having 15 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. Those from which impurities such as liquid fatty acids have been previously removed from these waxes are also preferred.
[0064]
Further, the wax preferably used is a low molecular weight alkylene polymer obtained by polymerizing alkylene with radical polymerization under high pressure or Ziegler catalyst or other catalyst under low pressure; alkylene obtained by thermally decomposing high molecular weight alkylene polymer Polymer: A low molecular weight alkylene polymer produced as a by-product in the polymerization of alkylene, separated and purified; a hydrocarbon polymer distillation residue obtained from a synthesis gas consisting of carbon monoxide and hydrogen by the age method, or a distillation residue And polymethylene wax obtained by extracting and fractionating specific components from a synthetic hydrocarbon obtained by hydrogenation. These waxes may contain an antioxidant. In order to improve the translucency of the fixed image, solid ester wax is preferable. When toner particles are directly produced in an aqueous medium, 1 to 40 parts by mass (more preferably 3 to 30 parts by mass) is blended with 100 parts by mass of the polymerizable monomer and contained in the toner particles. It is good.
[0065]
The colorant used in the present invention is carbon black or a known yellow / magenta / cyan colorant as shown below.
[0066]
As the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180, etc. are preferably used.
[0067]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48; 3, 48; 4, 57; 1, 81; 1, 122, 146, 166, 150, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.
[0068]
As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used. These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.
[0069]
The toner of the present invention may contain a charge control agent. For example, organometallic compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol. Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene and the like can be mentioned.
[0070]
Alternatively, nigrosine-modified products of nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and these Analogous onium salts such as phosphonium salts and their lake pigments, triphenylmethane dyes and their lake pigments (the rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid , Gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; Butyl tin borate, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate, and the like. These can be used alone or in combination of two or more.
[0071]
Silica can control the coalescence of primary particles arbitrarily to some extent depending on the starting material or oxidation conditions such as temperature. For example, the silica can be either a so-called dry method produced by vapor phase oxidation of silicon halide or alkoxide, or a so-called wet silica produced from alkoxide, water glass, etc. There are few silanol groups on the surface and in the silica fine powder, and Na₂O, SO₃ ^2-Dry silica with less production residue is preferred. In the case of dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process.
[0072]
The hydrophobic treatment of the silica fine particles is performed with a silane coupling agent. The silane coupling agent reacts with residual groups on the inorganic oxide fine particles or adsorbed water to achieve a uniform treatment, and is preferable in terms of stabilizing charging of the toner and imparting fluidity.
[0073]
The silane coupling agent is, for example, the following general formula
RmSiYn
R: alkoxy group
m: an integer from 1 to 3
Y: alkyl group
Hydrocarbon groups including vinyl, glycidoxy and methacryl groups
n: an integer from 1 to 3
The thing represented by is mentioned. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethyl Examples include methoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.
[0074]
More preferably,
C_aH_{2a + 1}-Si (OC_bH_{2b + 1})₃
a = 4-12, b = 1-3
It is. Here, when a in the general formula is smaller than 4, the treatment becomes easy, but the hydrophobicity cannot be sufficiently achieved. On the other hand, when a is larger than 12, the hydrophobicity is sufficient, but the coalescence of particles increases, and the fluidity imparting ability is lowered. When b is larger than 3, the reactivity is lowered and the hydrophobicity is not sufficiently performed. Therefore, a in the above general formula is 4 to 12, preferably 4 to 8, and b is 1 to 3, preferably 1 to 2.
[0075]
As the silane coupling agent containing nitrogen, hexamethyldisilazane is preferable from the viewpoint of handling properties such as ease of reaction control and from the viewpoint of charging stability.
[0076]
The treatment amount is preferably 1 to 50 parts by mass with respect to 100 parts by mass, and 3 to 40 parts by mass in order to uniformly treat the particles without coalescence.
[0077]
With respect to the silica fine particles in the present invention, the silica subjected to the hydrophobic treatment is further subjected to oil treatment. As the oil, silicone oil such as dimethylpolysiloxane and methylhydrogenpolysiloxane, paraffin, mineral oil and the like can be used, and among them, dimethylpolysiloxane having excellent environmental stability is preferable.
[0078]
Silica fine particles are preferably used in an addition amount of 0.05 to 2.5 parts by mass with respect to 100 parts by mass of the toner base.
[0079]
In the toner of the present invention, other additives such as a lubricant powder such as polyethylene fluoride powder, zinc stearate powder, polyvinylidene fluoride powder, cerium oxide powder, silicon carbide powder and the like within a range that does not substantially adversely affect the toner. An abrasive such as strontium titanate powder, an anti-caking agent such as aluminum oxide powder, or a conductivity imparting agent such as carbon black powder, zinc oxide powder or tin oxide powder, and organic and inorganic fine particles of reverse polarity. A small amount can be used as a developability improver.
[0080]
An image forming method to which the present invention can be applied will be described below with reference to the accompanying drawings.
[0081]
A developing device 4 in FIG. 1 is a two-component contact developing device (two-component magnetic brush developing device), and holds a developer composed of a carrier and toner on a developing sleeve 41 containing a magnet roller. The developing sleeve 41 is provided with a developer regulating blade 42 having a predetermined gap, and forms a thin developer layer on the developing sleeve 41 as the developing sleeve 41 rotates in the direction of arrow C. The developing sleeve 41 is arranged so as to have a predetermined gap with the photosensitive drum 1, and at the time of development, the developer thin layer formed on the developing sleeve 41 can be developed while being in contact with the photosensitive drum 1. Is set to In the developing device 4, there are stirring screws 43 and 44 for stirring the developer, which rotate in synchronization with the sleeve rotation, and have a function of stirring the supplied toner and carrier to give the toner a predetermined tribo. Yes. In the developer supply unit 5, there is a toner replenishment screw 51 that controls the amount of toner replenishment based on the number of rotations (rotation time).
[0082]
FIG. 2 is a view of the developing device 4 as viewed from above, and shows the circulation state of the developer and the longitudinal arrangement. As the screws 43 and 44 rotate, the developer circulates in the direction of the arrow. A sensor 44 is provided on the upstream side wall surface of the screw 44 of the developing device 4 to detect the change in the magnetic permeability of the developer to detect the toner concentration in the developer. An opening is provided. After performing the developing operation, the developer is conveyed to the sensor 44, where the toner concentration is detected, and in order to maintain the toner concentration in the developer constant according to the detection result, a developer supply unit (hereinafter referred to as a developer supplying unit) The toner is supplied from the T-CRG) 5 through the opening 46 of the developing device 4. The replenished toner is conveyed by the screw 44 in the direction of the arrow, mixed with the carrier and given an appropriate tribo and then carried to the vicinity of the sleeve 41, where a thin layer is formed on the developing sleeve 41 for development.
[0083]
The color laser printer shown in FIG. 3 has a plurality of process cartridges 7 and is continuously transferred to an intermediate transfer belt 8 which is a second image carrier, and continuously transferred to a four-drum system (a full-color print image is obtained). Inline) printer. In FIG. 3, an endless intermediate transfer belt 8 is suspended from a drive roller 8a, a tension roller 8b, and a secondary transfer counter roller 8c, and rotates in the direction of the arrow in the figure.
[0084]
Four process cartridges (hereinafter referred to as P-CRG) 7 are arranged in series with the intermediate transfer belt 8 corresponding to each color.
[0085]
Hereinafter, the P-CRG 7 will be described.
[0086]
The photosensitive drum 1 disposed in the P-CRG 7 that develops the yellow toner is uniformly charged to a predetermined polarity and potential by the primary charging roller 2 during the rotation process, and is then subjected to image exposure means (not shown). By receiving image exposure 3 by color separation / imaging exposure optical system of color original image, scanning exposure system by laser scan that outputs laser beam modulated in accordance with time series electric digital pixel signal of image information, etc. An electrostatic latent image corresponding to the first color component image (yellow component image) of the target color image is formed.
[0087]
Next, the electrostatic latent image is developed by the first developer 4 (yellow developer) with yellow toner as the first color. The yellow image formed on the photosensitive drum 1 enters the primary transfer nip portion with the intermediate transfer belt 8. In the transfer nip portion, a roller-like voltage applying member 9 is brought into contact with the back side of the intermediate transfer belt 8. The voltage application member 9 includes primary transfer bias sources 9a to 9d so that a bias can be applied independently at each port. The intermediate transfer belt 8 first transfers yellow at the port of the first color, and then performs multiple transfer of each color of magenta, cyan, and black sequentially from the photosensitive drum 1 corresponding to each color through the same process described above. The four-color full-color image formed on the intermediate transfer belt 8 is then collectively transferred to the transfer material P by the secondary transfer roller 10 and melted and fixed by a fixing device (not shown) to obtain a color print image.
[0088]
FIG. 4 is a schematic view of a process cartridge of a contact nonmagnetic one-component development system that can be used in the present invention. The cartridge 40 contains toner 42 and includes a toner carrier 4 that contacts the photoreceptor 1 and rotates in the direction of the arrow. The photoreceptor 1 is charged by contact charging means (not shown). Further, a developing blade 43 and a toner 42 for toner amount regulation and charging are attached to the toner carrier 4, and the application roller 41 that rotates in the direction of the arrow in order to charge the toner by friction with the toner carrier 4 is applied. It also has.
[0089]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this does not limit this invention at all. In addition, the number of parts in the following composition is part by mass unless otherwise specified.
[0090]
(Toner Production Example 1)
An aqueous dispersion medium and a polymerizable monomer composition were prepared as follows.
[0091]
Preparation of aqueous dispersion medium
The following components are mixed in a container with an internal volume of 200 liters, heated to 60 ° C., and then rotated at a rotational speed of 55 s using a high-speed rotary shear stirrer.^-1Stir with.
・ Water: 950 copies of water
・ 0.1 mol / liter-Na3PO4 aqueous solution 450 parts
Next, the inside of the container was replaced with nitrogen, and 1.0 mol / liter of CaCl 2 was added thereto.₂An aqueous dispersion medium containing fine particles of calcium phosphate was obtained by adding 68 parts of an aqueous solution and reacting them.
[0092]
Preparation of polymerizable monomer composition
-Styrene 100 copies
-N-Butyl acrylate 20 parts
・ Divinyl benzene 0.3 parts
-Colorant (CI Pigment Yellow 180) 6 parts
・ Di-t-butyl salicylic acid metal compound 2 parts
・ Polyester resin (acid value 20mgKOH / g) 15 parts
-Ester wax (melting point 60 ° C) 20 parts
Among the components described above, the components other than the polyester resin and the ester wax were mixed and dispersed for 3 hours using an attritor (manufactured by Mitsui Miike Kogyo Co., Ltd.). And mixed for 1 hour to obtain a polymerizable monomer composition.
[0093]
The rotational speed of the high-speed rotary shear stirrer containing the aqueous dispersion medium prepared above is 55 s.^-1Into this, the polymerizable monomer composition prepared above was charged and granulation was started. Three minutes after the start of granulation, 7 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) dissolved in 30 parts of styrene was added, and granulation was continued for another 12 minutes. After granulation for 15 minutes, transfer to a container of a stirrer equipped with a propeller stirring blade and rotate at a rotation speed of 0.83 s.^-1The reaction was continued at an internal temperature of 62 ° C. After 6 hours, the reaction temperature was raised to 80 ° C., and heating and stirring were continued for 5 hours to complete the polymerization. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, diluted hydrochloric acid was added to dissolve the dispersant, and solid-liquid separation, water washing, filtration, and drying were performed to obtain yellow toner particles. Table 1 shows various physical properties of the obtained toner. The weight average particle diameter was determined by Coulter counter TA-II type.
[0094]
(Toner Production Example 2)
In Toner Production Example 1, the colorant was C.I. I. Magenta toner particles were produced in the same manner as in Toner Production Example 1 except that the pigment red 150 was used. Table 1 shows various physical properties of the obtained toner.
[0095]
(Toner Production Example 3)
In Toner Production Example 1, the colorant was C.I. I. Cyan toner particles were produced in the same manner as in Toner Production Example 1 except that the pigment blue was changed to 15: 3. Various properties of the obtained toner are shown in the column of Toner Production Example 3 in Table 1.
[0096]
(Toner Production Example 4)
In toner production example 1, the rotational speed at the start of granulation of the high-speed rotary shear stirrer is 45 s.^-1In the same manner as in Toner Production Example 1, except that the colorant was changed to carbon black and the addition amount was 10 parts, black toner particles were produced. Various properties of the obtained toner are shown in the column of Toner Production Example 4 in Table 1.
[0097]
(Toner Production Example 5)
In Toner Production Example 1, yellow toner particles were produced in the same manner as in Toner Production Example 1 except that the polyester resin was changed to an epoxy resin having an acid value of 0.5 mgKOH / g. Various properties of the obtained toner are shown in the column of Toner Production Example 5 in Table 1.
[0098]
(Toner Production Example 6)
Magenta toner particles were produced in the same manner as in Toner Production Example 2 except that the polyester resin was changed to an epoxy resin having an acid value of 0.5 mgKOH / g in Toner Production Example 2. Various properties of the obtained toner are shown in the column of Toner Production Example 6 in Table 1.
[0099]
(Toner Production Example 7)
Cyan toner particles were produced in the same manner as in Toner Production Example 3, except that the polyester resin was changed to an epoxy resin having an acid value of 0.5 mgKOH / g in Toner Production Example 3. Various properties of the obtained toner are shown in the column of Toner Production Example 7 in Table 1.
[0100]
(Toner Production Example 8)
Black toner particles were produced in the same manner as in Toner Production Example 4 except that the polyester resin was changed to an epoxy resin having an acid value of 0.5 mgKOH / g in Toner Production Example 4. Various properties of the obtained toner are shown in the column of Toner Production Example 8 in Table 1.
[0101]
(Toner Production Example 9)
Yellow toner particles were produced in the same manner as in Toner Production Example 1 except that the polyester resin was changed to one having an acid value of 40 mgKOH / g in Toner Production Example 1. Various properties of the obtained toner are shown in the column of Toner Production Example 9 in Table 1.
[0102]
(Toner Production Example 10)
Magenta toner particles were produced in the same manner as in Toner Production Example 2, except that the polyester resin was changed to an acid value of 40 mgKOH / g in Toner Production Example 2. Various properties of the obtained toner are shown in the column of Toner Production Example 10 in Table 1.
[0103]
(Toner Production Example 11)
Cyan toner particles were produced in the same manner as in Toner Production Example 3, except that the polyester resin was changed to one having an acid value of 40 mgKOH / g in Toner Production Example 3. Various properties of the obtained toner are shown in the column of Toner Production Example 11 in Table 1.
[0104]
(Toner Production Example 12)
Black toner particles were produced in the same manner as in Toner Production Example 4 except that the polyester resin was changed to an acid value of 40 mgKOH / g in Toner Production Example 4. Various properties of the obtained toner are shown in the column of Toner Production Example 12 in Table 1.
[0105]
(Toner Production Example 13)
-100 parts of styrene-n-butyl acrylate copolymer
・ C. I. Pigment Yellow 180 6 parts
・ Di-tert-butyl salicylic acid metal compound 4 parts
・ Ester wax two parts of the wax
The mixture was melt-kneaded, cooled and coarsely pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized with an air jet type pulverizer. Further classification was performed to produce yellow toner particles. Various properties of the obtained toner are shown in the column of Toner Production Example 13 in Table 1.
[0106]
(Toner Production Example 14)
In Toner Production Example 1, the colorant was C.I. I. Magenta toner particles were produced in the same manner as in Toner Production Example 13 except that the pigment red 150 was used. Various physical properties of the obtained toner and various physical properties of the obtained toner are shown in the column of Toner Production Example 14 in Table 1.
[0107]
(Toner Production Example 15)
In Toner Production Example 1, the colorant was C.I. I. Cyan toner particles were produced in the same manner as in Toner Production Example 13 except that the pigment blue was changed to 15: 3. The properties of the obtained toner are shown in the column of Toner Production Example 15 in Table 1.
[0108]
(Toner Production Example 16)
In the toner production example 1, the colorant was changed to carbon black, the addition amount thereof was 10 parts, and the black toner particles were prepared in the same manner as in the toner production example 13 except that the pulverization force of fine pulverization was reduced by 5%. Manufactured. Various properties of the obtained toner are shown in the column of Toner Production Example 16 in Table 1.
[0109]
(Example of carrier production)
-Phenols 7.5 parts
-Formalin solution 11.25 parts of formalin solution
(Formaldehyde about 40%, methanol about 10%, the rest is water)
・ Lipophilic treatment with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane
Magnetite fine particles 53 parts
(Average particle size 0.24 μm, specific resistance 5 × 10⁵Ω · cm)
・ Lipophilic treatment with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane
α-Fe₂O₃35 parts of fine particles
(Average particle size 0.60 μm, specific resistance 2 × 10⁹Ω · cm)
Magnetite and α-Fe used here₂O₃The lipophilic treatment of 99 parts of magnetite and α-Fe₂O₃To each 99 parts, 1.0 part of γ-glycidoxypropyltrimethoxysilane was added and premixed and stirred at 100 ° C. for 30 minutes in a Henschel mixer.
[0110]
While maintaining the above materials and 11 parts of water at 40 ° C., mixing was performed for 1 hour. To this slurry, 2.0 parts of 28% by weight ammonia water as a basic catalyst and 11 parts of water were placed in a flask, heated and maintained at 85 ° C. over 40 minutes with stirring and mixing, and allowed to react for 3 hours. Was produced and cured. Then, after cooling to 30 ° C. and adding 100 parts of water, the supernatant was removed, the precipitate was washed with water and air-dried. Next, this was dried at 180 ° C. under reduced pressure (5 mmHg or less) to obtain spherical magnetic carrier core particles containing magnetite fine particles using a phenol resin as a binder resin.
[0111]
Coarse particles are removed from the particles with a 60-mesh and 100-mesh sieve, and then a multi-division wind classifier (Eppo Jet Lab EJ-L-3, manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect is used. Thus, fine powder and coarse powder were removed to obtain carrier core particles having a volume average 50% particle size of 35 μm. The obtained carrier core has a specific resistance of 2.2 × 10¹²Ω · cm and water content. It was 0.15 mass%.
[0112]
The obtained carrier core particles were put into a coater, and humidified nitrogen was introduced to adjust the moisture content to 0.3% by mass. Thereafter, 3% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent was applied to the core surface while continuously applying a shear stress. At that time, it was carried out while volatilizing the solvent at 40 ° C. and 13.3 kPa (100 torr) under a dry nitrogen stream. Subsequently, a mixture of 0.5% by mass of straight silicone resin in which all substituents are methyl groups and 0.015% by mass of γ-aminopropyltrimethoxysilane was coated with toluene as a solvent. At that time, it was carried out while volatilizing the solvent at 40 ° C. and 66.5 kPa (500 torr) under a dry nitrogen stream.
[0113]
Further, this magnetic coat carrier was baked at 140 ° C., and the aggregated coarse particles were cut with a 100 mesh sieve, and then fine particles and coarse particles were removed with a multi-division wind classifier to adjust the particle size distribution. Thereafter, humidity was adjusted for 100 hours in a hopper maintained at 23 ° C. and 60% to obtain a magnetic material-dispersed resin carrier.
[0114]
[Example 1]
For each of the yellow, magenta, cyan, and black toner bases obtained in Toner Production Example 1, Toner Production Example 2, Toner Production Example 3 and Toner Production Example 4, the silica fine particles are represented relative to 100 parts of the toner particles. 2 was mixed in a Henschel mixer 10B (manufactured by Mitsui Miike Chemical Co., Ltd.) under the conditions of a rotation speed of 3000 rpm and a stirring time of 4 minutes, to obtain a negatively triboelectrically charged color toner. At this time, the external additives to be added are not separately charged into the toner, but after all the external additives to be used are once charged in one container, they are added to the Henschel mixer in a state where the toner base is charged. .
[0115]
A developer was prepared by mixing 92 parts of the magnetic material-dispersed resin carrier prepared in the carrier production example with 8 parts of this toner.
[0116]
Based on the following evaluation method using the above toner and developer in a low-temperature and low-humidity environment of 15 ° C./10% RH, a medium-humidity environment of 20 ° C. and 55%, and a high-temperature and high-humidity environment of 30 ° C./80% RH. The full-color image forming apparatus shown in FIG. 3 has a process speed of 190 mm / s, a print speed of A4 horizontal 43 sheets / minute, a developer carrier rotation speed of 150% of the process speed, and a print ratio of 4% to the paper area. Of 75g / m²A continuous print test of 70,000 sheets of A4 plain paper was conducted. As a result, good results were obtained in all evaluations. The evaluation results are shown in Table 3. The types of silica fine particles are shown in Table 7.
[0117]
In all the examples, the evaluation results at the initial stage of printing based on the following evaluation methods were all good.
[0118]
<Toner aggregation measurement>
Using a powder tester (manufactured by Hosokawa Micron), 400 mesh (aperture 37 μm), 200 mesh (aperture 74 μm), and 100 mesh (aperture 147 μm) are overlapped in the order of narrowness of the mesh, that is, , 100 mesh is placed in the order of 400 mesh, 200 mesh, and 100 mesh so that 100 mesh is the highest. A sample is added on the set 100 mesh sieve, and vibration is applied for 15 seconds in the range where the amplitude of the vibration table is 0.6 ± 0.01 mm. Thereafter, the mass of the sample remaining on each sieve is measured, and the degree of aggregation is obtained based on the following equation. The smaller the cohesion value, the higher the fluidity of the toner.
[0119]
[Equation 5]

[0120]
<Evaluation method>
(1) Secondary color and solid black
After completion of the 70,000-sheet continuous printing test, 75g / m of A3 size that was fully conditioned in the test environment²On the paper, green, red, blue secondary colors and all solid black images were printed and visually evaluated based on the following criteria.
A: A uniform solid image is printed.
B: When viewed over light, it can be confirmed that the image is slightly uneven and solid.
C: A non-uniform solid image with a slight roughness
D: Uneven solid image with roughness
[0121]
(2) Halftone
After completion of the 70,000-sheet continuous printing test, 75g / m of A3 size that was fully conditioned in the test environment²On paper, yellow, magenta, cyan, black single color and secondary color halftone images of red, green, and blue were printed and visually evaluated according to the following criteria.
A: A uniform halftone image is printed
B: When viewed over light, it can be confirmed that the image is slightly uneven and non-uniform halftone image.
C: A slightly uneven halftone image
D: Non-uniform halftone image with roughness
[0122]
(3) Toner photosensitive drum fusion
After the continuous printing test for 70,000 sheets, the used photosensitive drum was subjected to microscopic observation after removing weak deposits remaining on the drum by air blow, and evaluated according to the following criteria.
A: No toner fusion is observed when a 50 × microscope observation is performed at positions approximately 5 cm from the center of the drum and both ends of the image forming area.
B: Toner fusion is confirmed when observation with a 50 × microscope is performed at positions approximately 5 cm from the center of the drum and both ends of the image forming area, but image omission due to adhesion does not occur.
C: When observed with a microscope, toner fusing was confirmed, and three or less image omissions caused by fusing per drum circumference.
D: When observed with a microscope, toner fusion was confirmed, and there were four or more image omissions due to fusion per drum circumference.
[0123]
(4) Charging member contamination
After completion of the 70,000-sheet continuous printing test, 75g / m of A3 size that was fully conditioned in the test environment²On paper, an all-white image of each color was printed and visually evaluated according to the following criteria.
A: Partial print is not confirmed. There is no local contamination on the charging member.
B: Partial print is not confirmed. Some local contamination is seen on the charging member. When the used charging member is replaced with a new one, it disappears
C: A very thin partial print can be seen. The charging member is locally soiled. When the used charging member is replaced with a new one, it disappears
D: Partial printing is confirmed. The charging member has a severe local stain. When the used charging member is replaced with a new one, it disappears
[0124]
(5) Developer durability
The amount of the agent per unit area (M / S) on the developer carrying member was measured at the initial stage and after completion of the continuous printing test for 70,000 sheets.
[0125]
(6) Environmental stability
The toner charge amount on the developer carrying member was measured based on the blow-off method at the initial stage and after completion of the 70,000 continuous printing test.
[0126]
[Examples 2 to 9]
According to the external additive formulation shown in Table 2, the same examination as in Example 1 was performed. The evaluation results are shown in Table 3 or Table 4.
[0127]
Example 10
In Example 1, except that the yellow, magenta, cyan and black toner base materials are changed to those obtained in Toner Production Example 5, Toner Production Example 6, Toner Production Example 7 and Toner Production Example 8. The same examination as in Example 1 was performed. The evaluation results are shown in Table 4.
[0128]
Example 11
In Example 1, except that the yellow, magenta, cyan and black toner base materials are changed to those obtained in Toner Production Example 9, Toner Production Example 10, Toner Production Example 11 and Toner Production Example 12, The same examination as in Example 1 was performed. The evaluation results are shown in Table 4.
[0129]
Example 12
In Example 1, except that the yellow, magenta, cyan and black toner bases are changed to those obtained in Toner Production Example 13, Toner Production Example 14, Toner Production Example 15 and Toner Production Example 16. The same examination as in Example 1 was performed. The evaluation results are shown in Table 4.
[0130]
Example 13
Using the toner and developer used in Example 1, the mechanism is changed so that the auto-refresh development method can be applied to the image forming apparatus shown in FIGS. 1, 2 and 3, and for replenishment in T-CRG The developer contains 15% by mass of a magnetic carrier and is used in a low-temperature and low-humidity environment of 15 ° C./10% RH, a medium-medium-humid environment of 20 ° C./55% RH, and a high-temperature high-humidity environment of 30 ° C./80% RH. The process speed is 230 mm / s, the printing speed is A4 horizontal 50 sheets / minute, the rotation speed of the developer carrier is 150% of the process speed, and the printing ratio is 4% with respect to the paper area, 75 g / m.²A continuous print test of 70,000 sheets of A4 plain paper was conducted. As a result, in all the environments, all the secondary colors and single colors, and the halftone, maintained a good image with no roughness after the end of durability, and neither charging member contamination nor photosensitive drum contamination was observed. After that, after printing 1,000 images with a print ratio of 1%, 20 images with a print ratio of 100% were printed, and immediately after that, a single color image was output for each color, and the above-mentioned 50,000 sheets of plain paper were printed continuously. The difference from the image density (measured with a reflection densitometer RD918 (manufactured by Macbeth Co.)) at the center of a solid monochrome image immediately after the test was examined. As a result, the difference in each color of each environment was within 0.1.
[0131]
[Comparative Examples 1 to 10]
According to the external additive formulation shown in Table 2, the same examination as in Example 1 was performed. The evaluation results are shown in Table 5 or 6. In Comparative Examples 8 to 10, a slight halftone was observed from the initial image in all colors in all environments.
[0132]
[Reference Example 1]
In all of the examples and comparative examples, the image forming apparatus used was changed to a process speed of 100 mm / s, a charging Vpp of 1200 V, a printing speed of 17 sheets / min. At the time when 50,000 sheets were passed, all the stickiness and halftone became rough, and the photosensitive drum contamination and charging member contamination were evaluated in each environment. As a result, for all the examples and comparative examples, all the evaluation items for each color were A rank.
[0133]
Further, when 20,000 sheets were passed, the results of the two rank improvement were shown for all the comparative examples and the whole solid texture and the halftone texture as compared with the present examination result table of Tables 5 and 6. . Photoconductor drum contamination and charging member contamination were all ranked A. All examples were all ranked A in the study of this condition.
[0134]
In Comparative Examples 8 to 10, the halftone of the initial image was ranked A in each environment.
[0135]
[Table 1]

[0136]
[Table 2]

[0137]
[Table 3]

[0138]
[Table 4]

[0139]
[Table 5]

[0140]
[Table 6]

[0141]
[Table 7]

[0142]
【The invention's effect】
A toner and an image forming method that satisfy high speed, high image quality, high durability, low environmental load, and high environmental stability can be provided.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an image forming method to which the present invention is applicable.
FIG. 2 is a view of the developing device of FIG. 1 as viewed from above.
FIG. 3 is an explanatory diagram of a color laser printer.
[Explanation of symbols]
1 Photosensitive drum
2 Charging roller
3 Laser light
4 Development device
5 Developer supply unit (replenishment toner kit)
6 Cleaner
7 Process cartridge (Process toner kit)
8 Intermediate transfer belt
9 Primary transfer electrode
10 Secondary transfer roller
11 Intermediate transfer belt cleaner
12 Registration roller
20 Ferroelectric non-volatile memory (FeRAM)
41 Development sleeve
42 blade
43 and 44 Developer stirring screw
45 Toner density detection sensor
46 Developer supply opening
51 screw

Claims (7)

The electrostatic image carrier for carrying the electrostatic image is charged, the electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with the toner of the developing means to form a toner image. A toner used in an image forming method in which a toner image on an electrostatic charge image carrier is transferred to a transfer material with or without an intermediate transfer member, and the toner image on the transfer material is fixed by a fixing unit. And
Charging is performed by a member in contact with the electrostatic image carrier, transfer is performed by a member in contact with a transfer member, and a toner image is toner used in an image forming method fixed by a thermal fixing unit,
The toner is externally added with at least two types of surface-treated silica fine particles having different BET specific surface areas, and the silica fine particles (a) having the smallest BET specific surface area, and then the silica fine particles (b) having the smallest BET specific surface area. The difference in the BET specific surface area is 30 m ² / g or more, the silica fine particles (a) and (b) are both treated with a silane coupling agent, and both are treated with a silicone oil treatment. Are each 2 to 40 parts by mass with respect to 100 parts by mass of the untreated silica fine particle matrix, and the silica fine particle (a) is the amount of oil treated per 1 m ² of BET specific surface area of the untreated silica fine particle matrix. Addition of (b) to 0.7 parts by weight to 90 parts by weight of silica fine particles (b) and 100 parts by weight of toner base particles per 100 parts by weight of toner base particles Toner, wherein the amount unit, is 0.2 times to 5.0 times. The BET specific surface area of the silica fine particles (a) is 15 m ² / g to 150 m ² / g, and the BET specific surface area of the silica fine particles (b) is 70 m ² / g to 300 m ² / g. The toner according to 1. The toner according to claim 1 or 2, wherein the toner contains at least a polar resin, and the acid value of the polar resin is 1 to 35 mgKOH / g. The average circularity measured by the toner flow type particle image measuring device is 0.950 to 1.000, and the circularity standard deviation is less than 0.040. Toner according to. The electrostatic image carrier for carrying the electrostatic image is charged, the electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with the toner of the developing means to form a toner image. An image forming method in which a toner image on an electrostatic charge image carrier is transferred to a transfer material via an intermediate transfer member, and the toner image on the transfer material is fixed by a fixing unit;
In the image forming method, charging is performed by a roller in contact with the electrostatic image bearing member, transfer is performed by a roller in contact with the intermediate transfer member and a roller in contact with the transfer material, and the toner image is fixed by a thermal fixing unit. Yes,
The toner is externally added with at least two types of surface-treated silica fine particles having different BET specific surface areas, and the silica fine particles (a) having the smallest BET specific surface area, and then the silica fine particles (b) having the smallest BET specific surface area. The difference in the BET specific surface area is 30 m ² / g or more, the silica fine particles (a) and (b) are both treated with a silane coupling agent, and both are treated with a silicone oil treatment. Are each 2 to 40 parts by mass with respect to 100 parts by mass of the untreated silica fine particle matrix, and the silica fine particle (a) is the amount of oil treated per 1 m ² of BET specific surface area of the untreated silica fine particle matrix. Addition of (b) to 0.7 parts by weight to 90 parts by weight of silica fine particles (b) and 100 parts by weight of toner base particles per 100 parts by weight of toner base particles Image forming method, wherein the amount unit, is 0.2 to 5.0 times. The image forming method according to claim 5, wherein the developing unit includes a developer composed of a nonmagnetic toner and a magnetic carrier. The replenishment developer includes at least a non-magnetic toner and a magnetic carrier, the developing means has a two-component developer, and the deteriorated carrier used in the developing means is sequentially collected to provide a fresh carrier in the replenishment developer. The image forming method according to claim 6, wherein the image forming method is adapted to a development system (auto-refresh development system) that replenishes water.

Images