JP4310092B2 - Two-component developer and full-color image forming method - Google Patents

Description

【００２８】
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。
【００２９】
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。
【００３０】
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。
【００３１】
【数２】

【００３２】
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。
【００３３】
【数３】

【００３４】
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。
【００３５】
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。
【００３６】
縮合系化合物の重量平均分子量はＧＰＣ（ゲルパーミエーションクロマトグラフィ）により、用いる縮合系化合物をそのままＴＨＦ溶媒に所定量（樹脂１質量部／テトラヒドロフラン１０００質量部）溶解し、サンプル処理フィルター（ポアサイズ０．４５〜０．５μｍ、たとえば、マイショリディスクＨ−２５−５ 東ソー社製、エキクロディスク２５ＣＲ ゲルマン サイエンス ジャパン社製などが利用できる）を通過させて不純物等の固形分を取り除いたものを試料として測定する。
【００３７】
ＧＰＣにおいては、４０℃のヒートチャンバ中でカラムを安定化させ、この温度におけるカラムに、溶媒としてＴＨＦを毎分１ｍｌの流速で流し、ＴＨＦ試料溶液を約１００μｌ注入して測定される。試料の分子量測定にあたっては、試料の有する分子量分布を、数種の単分散ポリスチレン標準試料により作成された検量線の対数値とカウント数との関係から算出する。検量線作成用の標準ポリスチレン試料としては、たとえば、東ソー社製あるいは、昭和電工社製の分子量が１０²〜１０⁷程度のものを用い、少なくとも１０点程度の標準ポリスチレン試料を用いるのが適当である。検出器にはＲＩ（屈折率）検出器を用いる。カラムとしては、市販のポリスチレンジェルカラムを複数本組み合わせるのが良く、たとえば昭和電工社製のｓｈｏｄｅｘ ＧＰＣ ＫＦ−８０１，８０２，８０３，８０４，８０５，８０６，８０７，８００Ｐの組み合わせや、東ソー社製のＴＳＫｇｅ１Ｇ１０００Ｈ（Ｈ_XL），Ｇ２０００Ｈ（Ｈ_XL），Ｇ３０００Ｈ（Ｈ_XL），Ｇ４０００Ｈ（Ｈ_XL），Ｇ５０００Ｈ（Ｈ_XL），Ｇ６０００Ｈ（Ｈ_XL），Ｇ７０００Ｈ（Ｈ_XL） ＴＳＫｇｕａｒｄｃｏｌｕｍｎの組み合わせが挙げられる。特に、カラム構成は、昭和電工社製Ａ−８０１、８０２、８０３、８０４、８０５、８０６及び８０７を連結したものが好ましい。
【００３８】
本発明のトナーを製造する方法は、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挙げられる。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。
【００３９】
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。
【００４０】
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。
【００４１】
以下に重合法トナーの材料に関して記載する。
【００４２】
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、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、２，４−ジメチルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン、ｐ−ｎ−ドデシルスチレン、ｐ−メトキシスチレン、ｐ−フェニルスチレン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。
【００４３】
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。
【００４４】
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。
【００４５】
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。
【００４６】
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。
【００４７】
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。
【００４８】
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。
【００４９】
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。
【００５０】
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。
【００５１】
本発明において縮合系化合物を用いる場合、例えば、ポリエステル、ポリカーボネート、フェノール樹脂、エポキシ樹脂、ポリアミド、セルロースなどが挙げられる。より好ましくは材料の多様性からポリエステルが望まれる。
【００５２】
該縮合系化合物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。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）配合し、トナー粒子に含有されるのが良い。
【００６１】
本発明において用いられる低軟化点物質としては、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。
【００６２】
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。
【００６３】
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。
【００６４】
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。
【００６５】
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。
【００６６】
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。
【００６７】
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。
【００６８】
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。
【００６９】
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。
【００７０】
本発明に使用できるトナーの添加剤としては、オイル処理されたシリカ，チタニア等の無機微粒子が好適に用いられる。その他、酸化ジルコニウム，酸化マグネシウムの如き酸化物の他に、炭化ケイ素，チッ化ケイ素，チッ化ホウ素，チッ化アルミニウム，炭酸マグネシウム，有機ケイ素化合物なども併用することが可能である。
【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点で好ましい。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Ｎａ₂Ｏ，ＳＯ₃ ^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りそれらも包含する。
【００７２】
更に、上記シリカは疎水化処理されていることが、トナーの帯電量の温度や湿度の如き環境依存性を少なくするため及びトナー表面からの過剰な遊離を防止するために良い。この疎水化処理剤としては、例えばシランカップリング剤、チタンカップリング剤，アルミニウムカップリング剤の如きカップリング剤が挙げられる。特にシランカップリング剤が、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、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
で表されるものであり、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。
【００７５】
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。
【００７６】
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。
【００７７】
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。
【００７８】
シリカのオイル処理に関しては、未処理のシリカに直接オイルで処理しても構わないが、上記疎水化処理をしたシリカにさらにオイル処理をすることが、帯電安定性の観点からより好ましい。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、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。処理に用いるオイル量は、シリカ微粒子母体１００質量部に対して２質量部〜４０質量部までが適量である。
【００７９】
シリカ微粒子の添加量としては、トナー母体１００質量部に対して、０．０５質量部〜２．５質量部までの添加量が好ましい使用範囲である。
【００８０】
本発明においては、チタニアも好適に利用できる。その製法としては何ら制約はないが、ハロゲン化物あるいはアルコキシドを気相下で酸化する方法、あるいは水存在下で加水分解しながら生成する方法などが使用できる。例えば、アモルファス酸化チタンあるいはアナターゼ型酸化チタン、ルチル型酸化チタンなどを用いることができる。また、それらチタニア微粒子は、シリカ同様疎水化処理やオイル処理を行うことができる。
【００８１】
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。
【００８２】
本発明が適用可能な画像形成方法の一例を添付図面を参照しながら以下に説明する。
【００８３】
図１は本発明の適用され得る画像形成装置を表わす図面である。この画像形成装置は、像担持体である感光体ドラム上にトナー像を形成する画像形成部３１Ｙ，３１Ｍ，３１Ｃ，３１ＢＫと、そのトナー像を一担転写する中間転写ベルト４ａ及びそのベルト４ａ上のトナー像を記録媒体２に転写する転写手段である二次転写ローラ４０、記録媒体２を中間転写ベルト４ａと二次転写ローラ４０間へ送り出す給紙手段及び転写手段へ記録媒体２を搬送する給送手段、定着手段、排紙手段を具備する。
【００８４】
以下画像形成について説明する。
【００８５】
図１に示すように画像形成装置には複数枚の記録媒体（例えば、記録紙、ＯＨＰシート、布等）２を積載収納する給紙カセット３ａが着脱自在に装着されている。ピックアップローラ３ｂにより給紙カセット３ａから給送された記録媒体２はリタードローラ対３ｃにより一枚ずつに分離され、搬送ローラ３ｄ，３ｆによってレジストローラ対３ｇに搬送される。
【００８６】
記録媒体２が搬送された時には、レジストローラ対３ｇは回転を停止しており、これのニップに突き当てられることにより記録媒体２は斜行を矯正される。
【００８７】
像担持体を含むプロセスカートリッジＢＹ，ＢＭ，ＢＣ，ＢＢには４ドラムフルカラー方式の場合、図のごとくイエロー、マゼンタ、シアン、ブラックの４つが並列配置されている。各々のプロセスカートリッジＢＹ，ＢＭ，ＢＣ，ＢＢに対し、それぞれ光学走査系が１Ｙ，１Ｍ，１Ｃ，１ＢＫが設けられ、画像信号により各色ごとの感光体ドラム上にトナー像が形成された後、転写ローラ４Ｙ，４Ｍ，４Ｃ，４ＢＫにより図示矢印方向に走行する中間転写ベルト４ａ上に各色トナーが重ねて転写される。
【００８８】
この後、記録媒体２は所定のタイミングで、２次転写ローラ４０に送り出され、中間転写ベルト４ａ上のトナー像が記録媒体２上へ転写され、定着器５で定着された後、排出ローラ対３ｈ，３ｉにより排出され、装置本体１４上のトレー６に積載される。
【００８９】
上記画像形成部３１Ｙ，３１Ｍ，３１Ｃ，３１ＢＫは光学走査系１Ｙ，１Ｍ，１Ｃ，１ＢＫを除いて夫々がプロセスカートリッジＢＹ，ＢＭ，ＢＣ，ＢＢを構成している。プロセスカートリッジの構成は同様であるのでプロセスカートリッジＢＹについてのべる。
【００９０】
図２に示すようにプロセスカートリッジＢＹは感光体ドラム７の周囲に帯電手段、露光部、現像手段、転写開口を配設したものである。この実施の形態では磁性キャリア粉を有する二成分現像剤を用いている。そこで本発明の実施の形態に用いられる感光体ドラム７としては、通常用いられている有機感光体等を用いることができる。
【００９１】
帯電手段は、導電性を有する帯電ローラー８である。この帯電ローラー８は、感光体ドラムの回転に従動する。
【００９２】
現像手段は本実施の形態では二成分現像剤を接触状態にして現像する方法を採用した。
【００９３】
図２には本実施の形態において用いた二成分磁気ブラシ現像用の現像手段１０が示されている。現像スリーブ１０ｄは中空円筒形であって回転自在に支持されている。現像スリーブ１０ｄ内には固定のマグネット１０ｃが配設されている。現像スリーブ１０ｄは感光体ドラム７と同方向に回転し、周面は感光体ドラム７の周面の移動方向に対して反対方向に移動する。感光体ドラム７と現像スリーブ１０ｄは非接触で０．２〜１．０ｍｍ程度の隙間があけられていて、現像剤が感光体ドラム７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。
【００９４】
キャリアを混合されてトナーは両端を除く長手方向の隔壁１０ｆで仕切られたケーシング内の撹拌スクリュー１０ｇ，１０ｈで供給される。不図示のトナー供給容器から供給されたトナーは撹拌スクリュー１０ｇの一端側へ落下して長手方向の一方向へ送られ乍ら撹拌され他端側の隔壁１０ｆのない部分をとおり、撹拌スクリュー１０ｈで一端側に移動して、ついで、一端側の隔壁１０ｆのない部分をとおり撹拌スクリュー１０ｇで送られながら撹拌され、循環する。
【００９５】
ここで感光体ドラム７に形成された静電潜像を、現像装置１０を用いて二成分磁気ブラシ法により顕像化する現像工程と現像剤の循環系について以下説明する。
【００９６】
まず、現像スリーブ１０ｄの回転に伴いマグネット１０ｃの極で汲み上げられた現像剤は、搬送される過程において、現像スリーブ１０ｄに対して垂直に配置された規制ブレード１０ｅによって規制され、現像スリーブ１０ｄ上に薄層形成される。ここで薄層形成された現像剤が、現像主極に搬送されてくると磁気力によって穂立ちが形成される。この穂状に形成された現像剤によって感光体ドラム７の静電潜像を現像し、その後反発磁界によって現像スリーブ１０ｄ上の現像剤は、現像容器１０ａ内に戻される。
【００９７】
現像スリーブ１０ｄには図示しない電源から直流電圧及び交流電圧が印加される。一般に二成分現像法においては交流電圧を印加すると現像効率が増し、画像は高品位になるが、逆にかぶりが発生しやすくなるということも生じる。このため、通常、現像スリーブ１０ｄに印加する直流電圧と感光体ドラム７の表面電位間に電位差を設けることによって、現像時に非画像領域にトナーが付くのを防止する。
【００９８】
このトナー像は、ついで図１中の中間転写装置４により中間転写体である中間転写ベルト４ａに転写される。中間転写装置４は無端状のベルト４ａを駆動ローラ４ｂ、従動ローラ４ｃ、及び二次転写対向ローラ４ｄに巻掛け、図１中矢印方向に回動される。さらに転写ベルト４ａ内には転写ローラ４Ｙ，４Ｍ，４Ｃ，４ＢＫを備え、各転写ローラは、ベルト４ａの内側から感光体ドラム７（７Ｙ，７Ｍ，７Ｃ，７ＢＫ）方向に加圧力を発生しつつ、高圧電源より給電されることで、ベルト４ａの裏側からトナーと逆極性の帯電を行なうことにより感光体ドラム７上のトナー像を順次中間転写ベルト４ａの上面に転写する。
【００９９】
中間転写ベルト４ａとしてはポリイミド樹脂からなるものを用いることができる。ベルト４ａの材質としてはポリイミド樹脂に限定されるものではなく、誘電体例えばポリカーボネイト樹脂や、ポリエチレンテレフタレート樹脂、ポリフッ化ビニリデン樹脂、ポリエチレンナフタレート樹脂、ポリエーテルエーテルケトン樹脂、ポリエーテルサルフォン樹脂、ポリウレタン樹脂などのプラスチックや、フッ素系、シリコン系のゴムを好適に用いることができる。
【０１００】
トナー像転写後の感光体ドラム７の面には転写残トナーが残留している。この転写残トナーは、帯電ローラーを通過して、現像部の磁気ブラシに捕捉されて、現像器に回収される。
【０１０１】
図３は、本発明に用い得る接触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。転写残トナーは、現像部における感光体とトナー担持体の電位の違いによって、トナー担持体側へ回収される。
【０１０２】
【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。
【０１０３】
（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。
【０１０４】
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質量部
・０．１モル／リットル−Ｎａ₃ＰＯ₄水溶液 ４５０質量部
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ＣａＣｌ₂水溶液６８質量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。
【０１０５】
重合性単量体組成物の調製
・スチレン １００質量部
・ｎ−ブチルアクリレート ２０質量部
・着色剤（Ｃ．Ｉ．ピグメントイエロー１８０） ６質量部
・ジ‐ｔ−ブチルサリチル酸金属化合物 ２質量部
・ポリエステル樹脂（数平均分子量３５００） １５質量部
・エステル系ワックス（融点６０℃） ２０質量部
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。
【０１０６】
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質量部を、スチレン３０質量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中トナーの製造例１の欄に示す。
【０１０７】
（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中トナーの製造例２の欄に示す。
【０１０８】
（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。
【０１０９】
（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質量部とした以外は、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。
【０１１０】
（トナーの製造例５）
トナーの製造例１において、エステル系ワックスとして融点が１１０℃のものに変更した以外は、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。
【０１１１】
（トナーの製造例６）
トナーの製造例２において、エステル系ワックスとして融点が１１０℃のものに変更した以外は、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。
【０１１２】
（トナーの製造例７）
トナーの製造例３において、エステル系ワックスとして融点が１１０℃のものに変更した以外は、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。
【０１１３】
（トナーの製造例８）
トナーの製造例４において、エステル系ワックスとして融点が１１０℃のものに変更した以外は、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。
【０１１４】
（トナーの製造例９）
トナーの製造例１において、縮合系化合物として数平均分子量が１３０００のポリエステル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９の欄に示す。
【０１１５】
（トナーの製造例１０）
トナーの製造例２において、縮合系化合物として数平均分子量が１３０００のポリエステル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１０の欄に示す。
【０１１６】
（トナーの製造例１１）
トナーの製造例３において、縮合系化合物として数平均分子量が１３０００のポリエステル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１１の欄に示す。
【０１１７】
（トナーの製造例１２）
トナーの製造例４において、縮合系化合物として数平均分子量が１３０００のポリエステル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１２の欄に示す。
【０１１８】
（トナーの製造例１３）
トナーの製造例１において、縮合系化合物として数平均分子量が１２００のポリエステル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１３の欄に示す。
【０１１９】
（トナーの製造例１４）
トナーの製造例２において、縮合系化合物として数平均分子量が１２００のポリエステル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１４の欄に示す。
【０１２０】
（トナーの製造例１５）
トナーの製造例３において、縮合系化合物として数平均分子量が１２００のポリエステル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１５の欄に示す。
【０１２１】
（トナーの製造例１６）
トナーの製造例４において、縮合系化合物として数平均分子量が１２００のポリエステル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１６の欄に示す。
【０１２２】
（トナーの製造例１７）
・スチレン １００質量部
・ｎ−ブチルアクリレート ２０質量部
・ポリエステル樹脂（数平均分子量３２００） １５質量部
・ドデカンチオール ５質量部
・四臭化炭素 １．５質量部
上記の成分を混合し、溶解したものを、非イオン性界面活性剤３．０質量部、及びアニオン性界面活性剤３．０質量部を添加したイオン交換水１４０質量部にフラスコ中で分散し、乳化させた。これに過硫酸アンモニウム０．１質量部を溶解したイオン交換水１０質量部を投入し、窒素置換を行った後、前記フラスコ内を撹拌しながら内容物を６５℃まで加熱し、５時間乳化重合をおこない、樹脂粒子分散液を調製した。
【０１２３】
一方、
・着色剤（Ｃ．Ｉ．ピグメントイエロー１８０） ２５質量部
・アニオン性界面活性剤（第一工業製薬社製：ネオゲンＳＣ） ３．５質量部
・イオン交換水 １２０質量部
上記成分を混合し、ホモジナイザーを用いて分散した後、循環式超音波分散機にかけて、平均粒径が１５０ｎｍの着色剤粒子分散液を調製した。
【０１２４】
一方、
エステル系ワックス（融点６０℃） １２．５質量部
アニオン性界面活性剤（第一工業製薬社製：ネオゲンＳＣ） ２．５質量部
イオン交換水 ６０質量部
上記成分を混合し、上記着色剤粒子分散液と同様の操作をおこない、中心粒型１８０ｎｍの離型剤分散液を得た。
【０１２５】
次に、上記で調製した
樹脂粒子分散液 ５０質量部
着色剤分散液 １２質量部
離型剤分散液 １２質量部
カチオン界面活性剤 ０．３５質量部
を丸型ステンレス鋼製フラスコ中でウルトラタラックスＴ５０（ＩＫＡ社製）で混合分散した後、加熱用オイルバスでフラスコを撹拌しながら５０℃まで加熱した。５０℃で６０分保持した後、コールターカウンター（コールター社製：マルチサイザー２）で粒子サイズを測定したところ、粒径６．２μｍの凝集粒子が生成していることが確認された。さらに加熱用オイルバスの温度を上げて５２℃で１時間保持した。
【０１２６】
この凝集体粒子を含む分散液に、樹脂粒子分散液１２．５質量部を緩やかに添加し、更に加熱用オイルバスの温度を上げて５４℃で１時間保持した。その後冷却、ろ過し、イオン交換水で５回洗浄した後、真空乾燥機を用いて乾燥させ、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中トナーの製造例１７の欄に示す。
【０１２７】
（トナーの製造例１８）
トナーの製造例１７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１７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１８の欄に示す。
【０１２８】
（トナーの製造例１９）
トナーの製造例１７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１７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１９の欄に示す。
【０１２９】
（トナーの製造例２０）
トナーの製造例１７において、着色剤をカーボンブラックに変更した以外は、トナーの製造例１７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２０の欄に示す。
【０１３０】
（トナーの製造例２１）
トナーの製造例１において、エステル系ワックスとして融点が４０℃のものに変更した以外は、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２１の欄に示す。
【０１３１】
（トナーの製造例２２）
トナーの製造例２において、エステル系ワックスとして融点が４０℃のものに変更した以外は、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２２の欄に示す。
【０１３２】
（トナーの製造例２３）
トナーの製造例３において、エステル系ワックスとして融点が４０℃のものに変更した以外は、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２３の欄に示す。
【０１３３】
（トナーの製造例２４）
トナーの製造例１において、エステル系ワックスとして融点が４０℃のものに変更した以外は、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２４の欄に示す。
【０１３４】
（トナーの製造例２５）
トナーの製造例１において、エステル系ワックスとして融点が１３０℃のものに変更した以外は、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２５の欄に示す。
【０１３５】
（トナーの製造例２６）
トナーの製造例２において、エステル系ワックスとして融点が１３０℃のものに変更した以外は、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２６の欄に示す。
【０１３６】
（トナーの製造例２７）
トナーの製造例３において、エステル系ワックスとして融点が１３０℃のものに変更した以外は、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２７の欄に示す。
【０１３７】
（トナーの製造例２８）
トナーの製造例１において、エステル系ワックスとして融点が１３０℃のものに変更した以外は、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２８の欄に示す。
【０１３８】
（トナーの製造例２９）
トナーの製造例１において、０．１モル／リットル−Ｎａ₃ＰＯ₄水溶液の代わりに、０．２モル／リットル−Ｎａ₃ＰＯ₄水溶液を用いて、また、１．０モル／リットルのＣａＣｌ₂水溶液の添加量を１３６質量部に変更した以外は、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２９の欄に示す。
【０１３９】
（トナーの製造例３０）
トナーの製造例２９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２９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３０の欄に示す。
【０１４０】
（トナーの製造例３１）
トナーの製造例２９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２９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３１の欄に示す。
【０１４１】
（トナーの製造例３２）
トナーの製造例２９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質量部とした以外は、トナーの製造例２９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３２の欄に示す。
【０１４２】
（トナーの製造例３３）
トナーの製造例１において、０．１モル／リットル−Ｎａ₃ＰＯ₄水溶液の代わりに、０．０７モル／リットル−Ｎａ₃ＰＯ₄水溶液を用いて、また、１．０モル／リットルのＣａＣｌ₂水溶液の添加量を５０質量部に変更した以外は、イエロートナーの製造例１と同様にして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３３の欄に示す。
【０１４３】
（トナーの製造例３４）
トナーの製造例３３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３３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３４の欄に示す。
【０１４４】
（トナーの製造例３５）
トナーの製造例３３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３３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３５の欄に示す。
【０１４５】
（トナーの製造例３６）
トナーの製造例３３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質量部とした以外は、トナーの製造例３３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３６の欄に示す。
【０１４６】
（キャリアの製造例）
・フェノール ７．５質量部
・ホルマリン溶液 １１．２５質量部
（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質量部
（平均粒径０．２４μｍ、比抵抗５×１０⁵Ω・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−Ｆｅ₂Ｏ₃微粒子 ３５質量部
（平均粒径０．６０μｍ、比抵抗２×１０⁹Ω・ｃｍ）
ここで用いたマグネタイト及びα−Ｆｅ₂Ｏ₃の親油化処理は、マグネタイト９９質量部及びα−Ｆｅ₂Ｏ₃９９質量部のそれぞれに対して１．０質量部の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。
【０１４７】
上記材料および水１１質量部を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質量部、および水１１質量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質量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。
【０１４８】
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２．２×１０¹²Ω・ｃｍであり、水分量が．０．１５質量％であった。
【０１４９】
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℃，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℃，５００ｔｏｒｒ，乾燥窒素気流下で溶媒を揮発させながら行なった。
【０１５０】
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。
【０１５１】
［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粒子それぞれについて、トナー粒子１００質量部に対して表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。
【０１５２】
得られたトナーは、各色ごとに４００ｇを補給用トナーカートリッジに充填し、４色の補給用トナーカートリッジとした。なお、トナーが消費されて空になった場合は、新しいトナーカートリッジと交換した。
【０１５３】
また、このトナー８質量部に対し、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質量部を混合して現像剤を調製し、この現像剤２５０ｇを各色ごとに図２に示した現像器に充填し、４色のプロセストナーカートリッジとした。
【０１５４】
以上のカートリッジを用いて、１５℃／１０％ＲＨの低温低湿環境および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１に示したフルカラー画像形成装置によって、プリント速度をＡ４横２３枚／分とし、紙面積に対するプリント比率４％での、７５ｇ／ｍ²Ａ４普通紙５万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。
【０１５５】
なお、すべての実施例および比較例において、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。
【０１５６】
＜評価方法＞
（１）がさつき
５万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／ｍ²紙において、各色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
【０１５７】
（２）感光ドラム上トナー融着
５万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、目視観察および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：目視でトナー融着観察されない。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、２００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：目視でトナー融着観察されない。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、２００倍のマイクロスコープ観察を行ったとき、３箇所以下の観察場所において、１５μｍ未満のトナー融着が、１ｃｍ×１ｃｍの視野で１個から２個確認される。
Ｃ：目視でトナー融着観察されない。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、２００倍のマイクロスコープ観察を行ったとき、１箇所以上の観察場所において、１５μｍ未満のトナー融着が、１ｃｍ×１ｃｍの視野で３個以上確認され、３箇所以下の観察場所において、１５μｍ以上のトナー融着が、１ｃｍ×１ｃｍの視野で１個から２個確認される。
Ｄ：目視でトナー融着観察される。あるいは、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、２００倍のマイクロスコープ観察を行ったとき、１箇所以上の観察場所において、１５μｍ未満のトナー融着が、１ｃｍ×１ｃｍの視野で３個以上確認され、１箇所以上の観察場所において、１５μｍ以上のトナー融着が、１ｃｍ×１ｃｍの視野で３個以上確認される。
【０１５８】
（３）帯電部材汚れ
５万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／ｍ²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
Ｂ：部分的なプリントが確認され、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
【０１５９】
なお、すべての実施例および比較例において、部分的なプリントが確認され、使用した帯電部材を新品の帯電部材と交換しても、それが消失しない例は無かった。
【０１６０】
（４）斑点状全べた画像抜け
５万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／ｍ²紙において、各色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：円形状に白く抜けた斑点が１個確認される。
Ｃ：円形状に白く抜けた斑点が２個以上確認される。
【０１６１】
（５）スジ状全べた画像抜け
５万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／ｍ²紙において、各色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、ごく僅かにスジ上に白く抜けた部分がある全べた画像であることが確認できる
Ｃ：幅０．３ｍｍ以下の僅かにスジ上に白く抜けた部分がある全べた画像であることが確認できる
Ｄ：幅０．３ｍｍよりも太いスジ上に白く抜けた部分がある全べた画像であることが確認できる
【０１６２】
（６）スジ状ハーフトーン画像抜け
５万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／ｍ²紙において、各色の全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：均一な全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、ごく僅かにスジ上に白く抜けた部分がある全ハーフトン画像であることが確認できる
Ｃ：幅０．３ｍｍ以下の僅かにスジ上に白く抜けた部分がある全ハーフトーン画像であることが確認できる
Ｄ：幅０．３ｍｍよりも太いスジ上に白く抜けた部分がある全ハーフトーン画像であることが確認できる
【０１６３】
（７）現像剤劣化
５万枚連続プリント試験終了後、現像剤中のトナーの粒度分布をコールターカウンターで測定し、重量平均粒径での１６％以上の粒子割合を算出した。
【０１６４】
［実施例２〜５］
表１の実施例２〜５に示したトナーを用い、それぞれのトナーについて表２に示した外添処方１に従い、実施例１と同様の検討を行った。評価結果を表３に示す。
【０１６５】
［参考例６］
実施例１において、用いる無機微粒子を表２に示した外添処方２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。
【０１６６】
［参考例７］
実施例１において、用いる無機微粒子を表２に示した外添処方３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。
【０１６７】
［参考例８］
実施例１において、図１に示したフルカラー画像形成装置を、接触非磁性一成分現像方式に改造した、現像剤２７０ｇを投入したプロセスカートリッジを作製し、現像時のバイアスを直流のみとし、帯電部材として帯電ローラーを採用し、現像前後の空白時には、直流および交流成分のバイアスを印加して、感光体上の残余のトナーを回収できるような電位に制御し、プリント速度をＡ４横１５枚／分とし、紙面積に対するプリント比率４％での、７５ｇ／ｍ²Ａ４普通紙１万枚連続プリント試験を行った。その時点で、実施例１に示した評価項目で各種評価を行った。評価結果を表４に示す。
【０１６８】
［実施例９］
実施例１において、一次転写ローラーを、ブレード状の接触転写部材に変更する以外は、実施例１と同様の検討を行った。評価結果を表４に示す。
【０１６９】
［実施例１０］
実施例１において、現像剤として用いる磁性キャリアをアクリルコートされたフェライトキャリアに変更し、トナー７質量部に対してキャリア９３質量部を混合して現像剤を調製した以外は、実施例１と同様の検討を行った。評価結果を表４に示す。
【０１７０】
［比較例１〜３］
表１の比較例１〜３に示したトナーを用い、それぞれのトナーについて表２に示した外添処方１に従い、実施例１と同様の検討を行った。その結果、表５に示したような問題が発生した。
【０１７１】
［比較例４］
表１の比較例４に示したトナーを用い、それぞれのトナーについて表２に示した外添処方１に従い、実施例１と同様の検討を行った。その結果、表５に示したような評価結果となったものの、プリント比率４％での、７５ｇ／ｍ²Ａ４普通紙５万枚連続プリント試験中において、印字１０００枚程度から、各色すべてにおいて飛び散りの目立つ画像となった。
【０１７２】
［比較例５］
実施例１において、用いる無機微粒子を表２に示した外添処方４に変更した以外は実施例１と同様に検討を行った。オイル処理シリカを含有しないトナーで評価を行ったので、表５に示したような問題が発生した。
【０１７３】
【表１】

【０１７４】
【表２】

【０１７５】
【表３】

【０１７６】
【表４】

【表５】

【０１７７】
【発明の効果】
高速、高画質、高耐久、低環境負荷、多種メディア対応および高環境安定性を満足するトナーおよびフルカラー画像形成方法を提供する。
【図面の簡単な説明】
【図１】本発明の適用される画像形成装置を表わす図である。
【図２】プロセスカートリッジの説明図である。
【図３】接触一成分現像方式のプロセスカートリッジの説明図である。[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]
Full-color image formation by electrophotography is basically a combination of yellow toner, magenta toner cyan toner and, if necessary, black toner, and is described in Patent Document 1 and the like. In a full-color copy image, toners of three colors or four colors including black are sequentially superimposed on transfer paper, and not only development characteristics but also transfer characteristics are important factors that determine image quality. Furthermore, in recent years, as image forming apparatuses such as full-color copiers and color laser printers are widely spread, their uses have been expanded to various demands, and requirements for image quality have become strict. For example, when copying an image such as a general forehead, catalog, or map, it is required to reproduce an extremely fine and faithful image without crushed or broken up to a minute part. Further, in an image forming apparatus such as a color laser printer using a digital image signal, a latent image is formed by gathering dots of a constant potential, and the solid area, the halftone area, and the light area change the dot area. It is expressed by In order to achieve high image quality, faithful development and faithful transfer of these images are required. Various proposals have been made so far to meet these requirements. However, we do not know that the demand for higher functionality such as higher image quality, higher durability, or further reduction of environmental impact will stop, and the development of new technologies that satisfy them will not stop. For example, intermediate transfer technology that enables printing on various media (Patent Document 2, etc.), contact charging technology that suppresses the generation of ozone (Patent Document 3, etc.), and cleanerless system that suppresses the generation of waste toner (Patent) Document 4 etc.) or cleaning recovery toner recycling technology (Patent Document 5 etc.), fixing technology not using oil or cleaning web (Patent Document 6 etc.), etc.
[0003]
However, while technological innovation has progressed in the above-mentioned parts, development of an image forming method that has all of them as a system and satisfies the performance aspects such as high image quality, high durability, and high stability is still in progress. The current situation is not reached.
[0004]
[Patent Document 1]
Japanese Patent Publication No.53-47176
[Patent Document 2]
JP-A-5-61385
[Patent Document 3]
Japanese Patent Laid-Open No. 5-119580
[Patent Document 4]
JP-A-5-224435
[Patent Document 5]
JP-A-8-69177
[Patent Document 6]
JP-A-9-292820
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a toner and a full-color image forming method that satisfy high speed, high image quality, high durability, low environmental load, compatibility with various media, and high environmental stability.
[0006]
[Means for Solving the Problems]
The above object is achieved by the present invention described below.
[0007]
  That is, image formation in which an electrostatic charge image carrier for carrying at least an electrostatic charge image for each color toner and a developing device having means for developing the electrostatic charge image is assigned, and the developing device is arranged in a tandem type. This method charges an electrostatic image carrier, forms an electrostatic image on the charged electrostatic image carrier, and develops the electrostatic image with a non-magnetic toner contained in a two-component developer included in the developing means. Then, a toner image is formed, and the toner image is transferred to an intermediate transfer member to form a full color image. The full color image is collectively transferred to a transfer material, and the full color image on the transfer material is fixed by a thermal fixing unit. An image forming method
  The electrostatic charge image bearing member is charged by a contact roller and developed by a two-component developer comprising a non-magnetic toner and a magnetic carrier, and the developing means also serves to collect the transfer residual toner and is a member that contacts the intermediate transfer member The toner image is transferred to the intermediate transfer member, the full-color image is transferred to the transfer material by a member in contact with the transfer material, and the fixing unit is a fixing unit that does not include an oil application mechanism. In the two-component developer used,
  The toner has at least a low softening point compound having a melting point of 50 ° C. to 120 ° C., and the toner surface hasTwo or more types of silica fine particles with different particle sizes treated with silane coupling agent and oilThe present invention is achieved by a two-component developer which is at least adhered and has a weight average particle diameter (D4) of 3 to 11 μm.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a developer having at least an electrostatic charge image carrier for supporting an electrostatic charge image for each color toner and a means for developing the electrostatic charge image is assigned, and the developing devices are arranged in a tandem type. An image forming method, charging an electrostatic charge image carrier, forming an electrostatic charge image on the charged electrostatic charge image carrier, developing the electrostatic charge image with toner of a developing unit, forming a toner image, An image forming method of forming a full-color image by transferring the toner image to an intermediate transfer member, transferring the full-color image to a transfer material at once, and fixing the full-color image on the transfer material by a thermal fixing unit,
The electrostatic image carrier is charged by a contact member and developed by a developer made of a non-magnetic toner. The developing means also collects residual transfer toner, and the toner image is transferred by a member in contact with the intermediate transfer member. In the image forming method in which the full-color image is transferred to the transfer material by a member that is transferred to the intermediate transfer member and is in contact with the transfer material, and the fixing unit is a fixing unit that does not include an oil application mechanism.
The toner has at least a low softening point compound having a melting point of 50 ° C. to 120 ° C., and at least oil-treated silica fine particles are adhered to the toner surface, and the weight average particle diameter (D4) of the toner Is 3 μm to 11 μm. By satisfying this relationship, high-quality images that reproduce all solid and highlight areas vividly, high durability with little deterioration even after printing many sheets, and generation of ozone while suppressing waste toner generation Low environmental impact with reduced printing, compatibility with various media that can print from thick paper to ultra-thin paper, high environmental stability that guarantees image quality from low temperature and low humidity environment to high temperature and high humidity environment, reduction of consumables, high speed printing, etc. A full-color image forming apparatus having performance can be produced.
[0009]
Basically, a developer is assigned to each color toner, and printing is accelerated by forming a full color image in one pass, ozone generation is suppressed by using contact charging and contact transfer, and the developing means collects residual toner after transfer. This also has the effect of suppressing the generation of waste toner by serving also, dealing with various media by using an intermediate transfer member, and reducing the number of consumables and parts by employing oilless fixing. However, performances such as high image quality, high durability, and high environmental stability cannot be achieved by simply combining them. For example, when the developing unit also serves to collect the transfer residual toner, the transfer residual toner naturally passes through the charged portion, so that contamination of the charging member, fusion to the electrostatic image carrier, and the like are very likely to occur. In addition, the collected transfer residual toner is naturally damaged as compared with the fresh toner, and the fact that it must be transferred two more times after it is developed again is an obstacle to maintaining the image quality. easy. Alternatively, in order to achieve oil-less fixing, toner releasability and storability must be highly harmonized, but generally developing properties and transferability are deteriorated when fixing properties are improved. It is. Therefore, in order to achieve high image quality by combining the above processes, various ideas are necessary.
[0010]
Specifically, the toner used contains at least a low softening point compound having a melting point of 50 ° C. to 120 ° C., and at least oil-treated silica fine particles are adhered to the surface, and When the weight average particle diameter (D4) is 3 μm to 11 μm, the above processes can be effectively combined.
[0011]
The low softening point material is essential for fixing by a fixing means that does not have an oil application mechanism. In addition, when the transfer residual toner passes through the contact charging portion, the toner containing the low softening point substance effectively prevents toner fusion to the photosensitive drum. The amount of the toner containing the low softening point substance varies depending on the toner production method, but since a very small amount of the low softening point substance is always present on the toner surface layer, it is considered that this causes a releasing effect. In general, in the contact charging unit, the contact charging member or the drum photosensitive member is scraped or worn by the applied high voltage or rubbing, but the effect of suppressing the wear can be obtained by using the toner containing the low softening point substance. Is also demonstrated. It is also presumed that a very small amount of a low softening point substance is applied to the drum photoconductor or the contact charging member and effectively reduces wear. Therefore, if the transfer residual toner having no low softening point substance passes through the contact charging portion, the damage alleviating effect is not given. In addition, when the toner passes through the contact charging unit, the toner may wear the charging member. With respect to this, it is speculated that the instantaneous pressure applied to the toner and the frictional shock are alleviated due to the elasticity of the low softening point substance itself.
[0012]
The melting point of the low softening point material needs to be 50 ° C to 120 ° C. When the temperature is less than 50 ° C., not only the storage stability of the toner deteriorates but also toner fusion may occur on the photosensitive drum due to rubbing or heat generated from the main body of the image forming apparatus. In addition, an appropriate amount or more of a low softening point substance may be applied to the contact charging member to cause charging failure. On the other hand, when the temperature is higher than 120 ° C., not only is it difficult to perform oilless fixing at a low temperature, but the releasing effect between the toner and the photosensitive drum may be reduced, which is not preferable.
[0013]
The toner surface must have oil-treated silica fine particles attached to it. First, the toner and silica fine particles themselves are prevented from being fused to the photosensitive drum. Second, it effectively suppresses the deterioration in transferability that is characteristic of toner containing a low softening point substance. Thirdly, deterioration of the developability and transferability of the transfer residual toner collected by the developing machine is prevented. Fourth, it effectively suppresses environmental changes in developability and transferability. The fine particles added to the surface of the toner and added for the purpose of imparting fluidity or stabilizing the charge have a much larger adhesion force to each member than the toner because of its fineness. If the oil-treated silica fine particles are not added to the toner, the fine particles released from the toner surface strongly adhere to the photosensitive drum due to the rubbing and pressure at the contact charging portion and cause image defects. However, when oil-treated silica fine particles are added, adhesion of free fine particles to the member is suppressed. Even when the oil contained in the silica fine particles contains not only the silica itself but also other fine particles added thereto, it is considered that the oil has an effect of weakening the adhesion of the fine particles to the member. In addition, the oil-treated silica has an effect of improving the disadvantageous transfer characteristics of the low softening point substance-containing toner. The toner containing a low softening point substance is not only effective for preventing the adhesion of a small amount of the low softening point substance on the surface layer, but also for the process of separating the toner from the member by electrostatic force, preventing the peeling due to viscous action. Will occur. However, when oil-treated silica is added to the toner, the transfer performance is equivalent to that of a toner containing no low softening point substance. In particular, in the secondary transfer process, which is a process of transferring from an intermediate transfer member to a transfer material, the transfer efficiency improvement effect is very large. In addition, the addition to the toner containing the low softening point substance also has the effect of suppressing the wear of the intermediate transfer member and extending the life, which means that the image is stable over a long period of time.
[0014]
Incidentally, the transfer residual toner collected by the developing device is damaged by passing through the contact charging portion. For example, the additive is buried in the surface layer of the toner and the fluidity is lowered, so that it becomes easier to charge up than a fresh toner, or it becomes easy to form agglomerates in the developing device. The toner agglomerates are liable to cause an adverse effect that they are developed but not transferred. Therefore, the generation of the toner agglomerates must be suppressed as much as possible. However, by using the toner to which the oil-treated silica fine particles are added, the charge-up is prevented and the spread of the difference in physical properties between the recovered transfer residual toner and the fresh toner can be suppressed. Presumably, charge-up is prevented, electrostatic aggregation of the collected transfer residual toner is suppressed, and generation of aggregates is suppressed. From this, it can be inferred that the oil on the silica surface layer has a sliding mitigating action. Further, the recovered transfer residual toner which has been damaged usually tends to greatly change the developability and transferability depending on the environment, but it also has an effect of preventing it. It has been found that the secondary transferability is prevented from deteriorating particularly in a high-temperature and high-humidity environment as compared with a toner having no oil-treated silica.
[0015]
The toner used must have a weight average particle diameter (D4) of 3 μm to 11 μm. If it is smaller than 3 μm, the developmental and transferable environmental fluctuations become large and transfer design becomes difficult. On the other hand, when the thickness exceeds 11 μm, the image quality is deteriorated and scattering in contact transfer is likely to occur. Also, toner fusion to the drum photoreceptor is disadvantageous.
[0016]
The contact charging member is more preferably an elastic roller having conductivity. It is because the effect of suppressing charging member contamination is great. This is because, if the adhesion force is weak, the deposit is separated from the charging roller by centrifugal force due to rotation. In addition, since the roller is a rotating body, a mechanism for removing weak deposits can be provided (for example, a cleaning sheet on a film is brought into contact with the roller). In the present invention, the cleaning effect when the cleaning sheet is provided is also very large. 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 roller is preferably 5 to 500 N / m.
[0017]
The contact transfer member is more preferably an elastic roller having conductivity. Although the detailed mechanism is not well understood at present, when the toner containing a low softening point substance is used and the transfer residual toner is recovered by the developing device and reused, the scattering and the roughness particularly in the secondary transfer process may occur. Become advantageous. 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.
[0018]
In the present invention, it is more preferable to use a two-component developer composed of a non-magnetic toner and a magnetic carrier. This is because it is advantageous in terms of efficiently collecting the transfer residual toner and charging the collected toner efficiently.
[0019]
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. Not only is the recovered transfer residual toner charged efficiently, but the toner is less likely to damage the toner, so there is less re-damage to the recovered transfer residual toner that has already been damaged.
[0020]
As a more preferred embodiment of the present invention, two or more kinds of oil-treated silica fine particles having different particle diameters are used in combination. As a result, processes such as development, member adhesion, and transfer are further stabilized, and dot reproducibility is improved. As described above, the oil-treated silica plays a very important role in the present invention. However, the small particle size silica has a fluidity imparting and charge holding effect, and the large particle size silica plays a role of preventing toner deterioration. By fulfilling the above, the effect of the present invention is further enhanced.
[0021]
In the present invention, it is also preferable to use titania fine particles in addition to the oil-treated silica fine particles. The titania fine particles have an effect of preventing charge-up, and in particular, when used in combination with oil-treated silica fine particles, the effect of preventing the performance deterioration of the recovered transfer residual toner is increased. Furthermore, by applying oil treatment to titania fine particles, a margin for preventing the adhesion of fine particles to various members is widened, and image quality can be guaranteed for a longer period of time.
[0022]
As the shape of the toner, it is more preferable that the average circularity measured by the flow type particle image measuring apparatus is 0.950 to 1.000, and the circularity standard deviation is less than 0.040. When the average circularity is within the range, the load such as pressure and rubbing on the toner is reduced from the round shape of the toner. When the average circularity is within the range, the transfer residual toner passes through the contact charging portion with a lighter load, so that the toner member is less likely to be fused. At the same time, this means that the difference in physical properties between the collected transfer residual toner and the fresh toner is reduced, thereby enhancing the function of maintaining developability and transferability. In addition, when the average circularity is within the range, the transfer efficiency is good, and a more efficient toner consumption system can be constructed. Further, when the circularity standard deviation is less than 0.040, it means that the shape distribution of the toner is narrow, so that the toner fusion, deterioration, developability or transferability to the member is also good. In the present invention, it is more preferable to set the shape within the above range with toner produced in an aqueous medium, since the toner is resistant to adhesion of members. Furthermore, since the toner surface layer has an appropriate low softening point substance, and contamination of members is most effectively prevented, it is more preferable to produce the toner by suspension polymerization.
[0023]
The toner of the present invention more preferably contains at least a condensation compound. If it is included, toner fusion to a member such as a drum photoreceptor is reduced. It is estimated that the condensed compound having polarity has an effect of further reducing the adhesion. The number average molecular weight of the condensed compound is preferably 2000 to 10,000, since it not only becomes an appropriate fixing temperature range but also damage and fusion between the toner and the member are further reduced. As the molecular weight decreases from 2000, the compound begins to deteriorate due to rubbing, and the effect of the present invention is weakened. On the other hand, when it exceeds 10,000, the effect of the present invention gradually weakens in the direction in which the added fine particles on the toner surface layer are easily released from the balance between mechanical strength and electrostatic interaction.
[0024]
In the present invention, the average particle diameter of the toner was measured using a Coulter counter. That is, a Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter, Inc.) is used as a measuring device. As the electrolyte, first grade sodium chloride is used to prepare an approximately 1% NaCl aqueous solution. For example, ISOTON-II (manufactured by Coulter) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toners are measured by using the measuring apparatus with a 100 μm aperture as the aperture. Distribution was calculated. Then, a ratio of less than 5.04 μm obtained from the number distribution related to the present invention was obtained.
[0025]
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Use 13 channels less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm.
[0026]
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.
[0027]
[Expression 1]

[0028]
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.
[0029]
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.
[0030]
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.
[0031]
[Expression 2]

[0032]
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.
[0033]
[Equation 3]

[0034]
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.
[0035]
To measure the shape of the toner particles, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 toner particles are obtained. Measure above. After the measurement, this data is used to obtain the equivalent circle diameter, circularity frequency distribution, etc. of the toner particles.
[0036]
The weight-average molecular weight of the condensation compound is determined by GPC (gel permeation chromatography), and the condensation compound to be used is dissolved in a predetermined amount (1 part by mass of resin / 1000 parts by mass of tetrahydrofuran) as it is in a sample processing filter (pore size 0.45). -0.5 μm, for example, Mysholy disk H-25-5 manufactured by Tosoh Corporation, Excrodisk 25CR manufactured by Gelman Science Japan, etc. can be used) and the solid content such as impurities removed is measured as a sample. To do.
[0037]
In GPC, the column is stabilized in a heat chamber at 40 ° C., THF is flowed as a solvent at a flow rate of 1 ml / min, and about 100 μl of a THF sample solution is injected into the column at this temperature. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, a molecular weight of 10 manufactured by Tosoh Corporation or Showa Denko KK is 10²-10⁷It is appropriate to use a standard polystyrene sample of about 10 points. An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. TSKge1G1000H (H_XL), G2000H (H_XL), G3000H (H_XL), G4000H (H_XL), G5000H (H_XL), G6000H (H_XL), G7000H (H_XL) The combination of TSK guard column is mentioned. In particular, the column structure is preferably a combination of A-801, 802, 803, 804, 805, 806 and 807 manufactured by Showa Denko KK.
[0038]
The toner of the present invention can be produced by directly using a suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842. Production method; Monomer production includes the production of toner particles by emulsion polymerization represented by a soap-free polymerization method in which toner particles are directly polymerized in the presence of a water-soluble polymerization initiator to produce toner particles. . 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.
[0039]
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.
[0040]
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.
[0041]
The following describes the material of the polymerization toner.
[0042]
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.
[0043]
In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more.
[0044]
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.
[0045]
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.
[0046]
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.
[0047]
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.
[0048]
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.
[0049]
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.
[0050]
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.
[0051]
In the present invention, when a condensation compound is used, for example, polyester, polycarbonate, phenol resin, epoxy resin, polyamide, cellulose and the like can be mentioned. More preferably, polyester is desired due to the variety of materials.
[0052]
Examples of the method for producing the condensation compound include a synthesis method by oxidation reaction, synthesis from carboxylic acid and derivatives thereof, ester group introduction reaction represented by Michael addition reaction, dehydration condensation reaction from carboxylic acid compound and alcohol compound. , A reaction from an acid halide and an alcohol compound, and 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]

(In the formula, 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 a bisphenol derivative represented by the following formula (II)
[0055]
[Chemical formula 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 group or alkenyl group having 6 to 18 carbon atoms or its 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 within a range not adversely affecting 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. When toner particles are directly produced in an aqueous medium, 1 to 30 parts by mass (more preferably 2 to 25 parts by mass) is blended with 100 parts by mass of the polymerizable monomer and contained in the toner particles. It is good to be done.
[0061]
Examples of the low softening point substance 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. Derivatives such as graft compounds and block compounds are preferred, 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.
[0062]
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.
[0063]
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 to be done.
[0064]
The colorant used in the present invention is carbon black or a known yellow / magenta / cyan colorant as shown below.
[0065]
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.
[0066]
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.
[0067]
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.
[0068]
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.
[0069]
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. , 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.
[0070]
As the toner additive that can be used in the present invention, oil-treated inorganic fine particles such as silica and titania are preferably used. In addition to oxides such as zirconium oxide and magnesium oxide, silicon carbide, silicon nitride, boron nitride, aluminum nitride, magnesium carbonate, organosilicon compounds, and the like can be used in combination.
[0071]
Silica is preferable in that the coalescence of the primary particles can be controlled arbitrarily to some extent depending on the starting material or the 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 dry silica called fumed silica and 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, SO_Three ^2-Dry silica with less production residue is preferred. In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.
[0072]
Furthermore, the silica is preferably hydrophobized in order to reduce the dependency of the toner charge amount on the environment, such as temperature and humidity, and to prevent excessive release from the toner surface. Examples of the hydrophobizing agent include coupling agents such as a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. In particular, the silane coupling agent reacts with residual groups on the inorganic oxide fine particles or adsorbed water to achieve a uniform treatment, which is preferable in terms of stabilizing charging of the toner and imparting fluidity.
[0073]
The silane coupling agent has 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
For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxy Examples thereof include silane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.
[0074]
More preferably,
C_aH_{2a + 1}-Si (OC_bH_{2b + 1})_Three
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, if a is greater than 12, the hydrophobicity is sufficient, but the coalescence between the particles increases, and the fluidity imparting ability decreases.
[0075]
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.
[0076]
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.
[0077]
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.
[0078]
With respect to the oil treatment of silica, untreated silica may be directly treated with oil, but it is more preferable from the viewpoint of charging stability that the hydrophobized silica is further treated with oil. As the oil, dimethylpolysiloxane, methylhydrogenpolysiloxane, paraffin, mineral oil and the like can be used, and among them, dimethylpolysiloxane excellent in environmental stability is preferable. The amount of oil used in the treatment is 2 to 40 parts by mass with respect to 100 parts by mass of the silica fine particle matrix.
[0079]
The addition amount of the silica fine particles is preferably in the range of 0.05 to 2.5 parts by mass with respect to 100 parts by mass of the toner base.
[0080]
In the present invention, titania can also be suitably used. The production method is not particularly limited, and a method of oxidizing a halide or alkoxide in a gas phase or a method of producing a product by hydrolysis in the presence of water can be used. For example, amorphous titanium oxide, anatase titanium oxide, rutile titanium oxide, or the like can be used. In addition, these titania fine particles can be subjected to a hydrophobic treatment or an oil treatment as in the case of silica.
[0081]
In the toner of the present invention, other additives such as a lubricant powder such as polyethylene fluoride powder, zinc stearate powder and polyvinylidene fluoride powder; 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.
[0082]
An example of an image forming method to which the present invention can be applied will be described below with reference to the accompanying drawings.
[0083]
FIG. 1 shows an image forming apparatus to which the present invention can be applied. This image forming apparatus includes image forming portions 31Y, 31M, 31C, and 31BK that form toner images on a photosensitive drum that is an image carrier, an intermediate transfer belt 4a that transfers the toner images in a single transfer, and the belt 4a. The recording medium 2 is conveyed to a secondary transfer roller 40 which is a transfer means for transferring the toner image to the recording medium 2, a paper feed means for feeding the recording medium 2 between the intermediate transfer belt 4a and the secondary transfer roller 40, and a transfer means. A feeding unit, a fixing unit, and a paper discharge unit are provided.
[0084]
Image formation will be described below.
[0085]
As shown in FIG. 1, a paper feed cassette 3a for loading and storing a plurality of recording media (for example, recording paper, OHP sheets, cloth, etc.) 2 is detachably mounted on the image forming apparatus. The recording medium 2 fed from the paper feed cassette 3a by the pickup roller 3b is separated one by one by the retard roller pair 3c and conveyed to the registration roller pair 3g by the conveying rollers 3d and 3f.
[0086]
When the recording medium 2 is transported, the registration roller pair 3g stops rotating, and the recording medium 2 is corrected in skew by being abutted against the nip thereof.
[0087]
In the case of the four-drum full-color system, the process cartridges BY, BM, BC, and BB including the image carrier are arranged in parallel as shown in the drawing, yellow, magenta, cyan, and black. For each of the process cartridges BY, BM, BC, and BB, optical scanning systems 1Y, 1M, 1C, and 1BK are provided, and toner images are formed on the photosensitive drums for the respective colors by image signals, and then transferred. Each color toner is superimposed and transferred onto the intermediate transfer belt 4a running in the direction of the arrow by the rollers 4Y, 4M, 4C, and 4BK.
[0088]
Thereafter, the recording medium 2 is sent to the secondary transfer roller 40 at a predetermined timing, and the toner image on the intermediate transfer belt 4 a is transferred onto the recording medium 2 and fixed by the fixing device 5. It is discharged by 3h, 3i and loaded on the tray 6 on the apparatus main body 14.
[0089]
The image forming units 31Y, 31M, 31C, 31BK constitute process cartridges BY, BM, BC, BB, except for the optical scanning systems 1Y, 1M, 1C, 1BK. Since the configuration of the process cartridge is the same, the process cartridge BY will be described.
[0090]
As shown in FIG. 2, the process cartridge BY is provided with a charging unit, an exposure unit, a developing unit, and a transfer opening around the photosensitive drum 7. In this embodiment, a two-component developer having magnetic carrier powder is used. Therefore, as the photoreceptor drum 7 used in the embodiment of the present invention, a commonly used organic photoreceptor can be used.
[0091]
The charging means is a charging roller 8 having conductivity. The charging roller 8 follows the rotation of the photosensitive drum.
[0092]
In the present embodiment, the developing means employs a method of developing with the two-component developer in contact.
[0093]
FIG. 2 shows the developing means 10 for developing the two-component magnetic brush used in the present embodiment. The developing sleeve 10d has a hollow cylindrical shape and is rotatably supported. A fixed magnet 10c is disposed in the developing sleeve 10d. The developing sleeve 10 d rotates in the same direction as the photosensitive drum 7, and the peripheral surface moves in a direction opposite to the moving direction of the peripheral surface of the photosensitive drum 7. The photosensitive drum 7 and the developing sleeve 10d are not in contact with each other, and a gap of about 0.2 to 1.0 mm is formed so that the developer can be developed while being in contact with the photosensitive drum 7. .
[0094]
The toner mixed with the carrier is supplied by stirring screws 10g and 10h in a casing partitioned by a partition wall 10f in the longitudinal direction excluding both ends. The toner supplied from a toner supply container (not shown) falls to one end side of the stirring screw 10g, is sent in one direction in the longitudinal direction, is stirred, passes through the part without the partition wall 10f on the other end side, and is stirred by the stirring screw 10h. It moves to one end side, and then is stirred and circulated while being fed by a stirring screw 10g through a portion without the partition wall 10f on one end side.
[0095]
Here, the developing process for developing the electrostatic latent image formed on the photosensitive drum 7 by the two-component magnetic brush method using the developing device 10 and the developer circulation system will be described below.
[0096]
First, the developer pumped up by the pole of the magnet 10c with the rotation of the developing sleeve 10d is regulated by the regulating blade 10e arranged perpendicular to the developing sleeve 10d in the process of being conveyed, and is placed on the developing sleeve 10d. A thin layer is formed. Here, when the developer formed in a thin layer is conveyed to the development main electrode, a spike is formed by the magnetic force. The electrostatic latent image on the photosensitive drum 7 is developed with the developer formed in the spike shape, and then the developer on the developing sleeve 10d is returned to the developing container 10a by a repulsive magnetic field.
[0097]
A DC voltage and an AC voltage are applied to the developing sleeve 10d from a power source (not shown). In general, in the two-component development method, when an AC voltage is applied, the development efficiency increases and the image becomes high-quality, but conversely, fogging easily occurs. For this reason, a potential difference is usually provided between the DC voltage applied to the developing sleeve 10d and the surface potential of the photosensitive drum 7, thereby preventing the toner from attaching to the non-image area during development.
[0098]
This toner image is then transferred to the intermediate transfer belt 4a, which is an intermediate transfer body, by the intermediate transfer device 4 in FIG. The intermediate transfer device 4 winds an endless belt 4a around a driving roller 4b, a driven roller 4c, and a secondary transfer counter roller 4d, and is rotated in the direction of the arrow in FIG. Furthermore, transfer rollers 4Y, 4M, 4C, 4BK are provided in the transfer belt 4a, and each transfer roller generates pressure from the inside of the belt 4a in the direction of the photosensitive drum 7 (7Y, 7M, 7C, 7BK). The toner image on the photosensitive drum 7 is sequentially transferred onto the upper surface of the intermediate transfer belt 4a by charging from the back side of the belt 4a with a reverse polarity to the toner by being supplied with power from the high voltage power source.
[0099]
As the intermediate transfer belt 4a, one made of polyimide resin can be used. The material of the belt 4a is not limited to polyimide resin, but dielectrics such as polycarbonate resin, polyethylene terephthalate resin, polyvinylidene fluoride resin, polyethylene naphthalate resin, polyether ether ketone resin, polyether sulfone resin, polyurethane Plastics such as resins, fluorine-based and silicon-based rubbers can be preferably used.
[0100]
Transfer residual toner remains on the surface of the photosensitive drum 7 after the toner image is transferred. This untransferred toner passes through the charging roller, is captured by the magnetic brush of the developing unit, and is collected by the developing device.
[0101]
FIG. 3 is a schematic view of a process cartridge of a contact 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. The untransferred toner is collected on the toner carrier side due to the difference in potential between the photosensitive member and the toner carrier in the developing unit.
[0102]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this does not limit this invention at all.
[0103]
(Toner Production Example 1)
An aqueous dispersion medium and a polymerizable monomer composition were prepared as follows.
[0104]
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.
・ 950 parts by weight of water
・ 0.1 mol / liter-Na_ThreePO_Four450 parts by mass of aqueous solution
Next, the inside of the container is purged with nitrogen, and 1.0 mol / liter of CaCl₂68 parts by mass of an aqueous solution was added and reacted to obtain an aqueous dispersion medium containing fine particles of calcium phosphate.
[0105]
Preparation of polymerizable monomer composition
・ 100 parts by mass of styrene
・ N-butyl acrylate 20 parts by mass
-Colorant (CI Pigment Yellow 180) 6 parts by mass
・ Metal compound of di-t-butylsalicylate 2 parts by mass
-Polyester resin (number average molecular weight 3500) 15 parts by mass
-Ester wax (melting point 60 ° C) 20 parts by mass
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.
[0106]
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 by mass of 2,2'-azobis (2,4-dimethylvaleronitrile) dissolved in 30 parts by mass 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. Various properties of the obtained toner are shown in the column of Toner Production Example 1 in Table 1.
[0107]
(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. Various properties of the obtained toner are shown in the column of Toner Production Example 2 in Table 1.
[0108]
(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.
[0109]
(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.^-1The black toner particles were produced in 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 by mass. Various properties of the obtained toner are shown in the column of Toner Production Example 4 in Table 1.
[0110]
(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 ester wax was changed to one having a melting point of 110 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 5 in Table 1.
[0111]
(Toner Production Example 6)
Magenta toner particles were produced in the same manner as in Toner Production Example 2, except that the ester wax was changed to 110 ° C. in the toner production example 2. Various properties of the obtained toner are shown in the column of Toner Production Example 6 in Table 1.
[0112]
(Toner Production Example 7)
Cyan toner particles were produced in the same manner as in Toner Production Example 3 except that in Example 3 of toner, the ester wax was changed to one having a melting point of 110 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 7 in Table 1.
[0113]
(Toner Production Example 8)
Black toner particles were produced in the same manner as in Toner Production Example 4 except that the ester wax was changed to 110 ° C. in the toner production example 4. Various properties of the obtained toner are shown in the column of Toner Production Example 8 in Table 1.
[0114]
(Toner Production Example 9)
In Toner Production Example 1, yellow toner particles were produced in the same manner as in Toner Production Example 1, except that the condensation compound was changed to a polyester resin having a number average molecular weight of 13,000. Various properties of the obtained toner are shown in the column of Toner Production Example 9 in Table 1.
[0115]
(Toner Production Example 10)
Magenta toner particles were produced in the same manner as in Toner Production Example 2, except that the polyester compound having a number average molecular weight of 13000 was changed as the condensation compound in Toner Production Example 2. Various properties of the obtained toner are shown in the column of Toner Production Example 10 in Table 1.
[0116]
(Toner Production Example 11)
Cyan toner particles were produced in the same manner as in Toner Production Example 3 except that the polyester compound having a number average molecular weight of 13000 was used as the condensation compound in Toner Production Example 3. Various properties of the obtained toner are shown in the column of Toner Production Example 11 in Table 1.
[0117]
(Toner Production Example 12)
In Toner Production Example 4, black toner particles were produced in the same manner as in Toner Production Example 4 except that the condensation compound was changed to a polyester resin having a number average molecular weight of 13000. Various properties of the obtained toner are shown in the column of Toner Production Example 12 in Table 1.
[0118]
(Toner Production Example 13)
In Toner Production Example 1, yellow toner particles were produced in the same manner as in Toner Production Example 1, except that the condensation compound was changed to a polyester resin having a number average molecular weight of 1200. Various properties of the obtained toner are shown in the column of Toner Production Example 13 in Table 1.
[0119]
(Toner Production Example 14)
Magenta toner particles were produced in the same manner as in Toner Production Example 2 except that the polyester compound having a number average molecular weight of 1200 was used as the condensation compound in Toner Production Example 2. Various properties of the obtained toner are shown in the column of Toner Production Example 14 in Table 1.
[0120]
(Toner Production Example 15)
Cyan toner particles were produced in the same manner as in Toner Production Example 3 except that the polyester compound having a number average molecular weight of 1200 was used as the condensation compound in Toner Production Example 3. Various properties of the obtained toner are shown in the column of Toner Production Example 15 in Table 1.
[0121]
(Toner Production Example 16)
In Toner Production Example 4, black toner particles were produced in the same manner as in Toner Production Example 4 except that the condensation compound was changed to a polyester resin having a number average molecular weight of 1200. Various properties of the obtained toner are shown in the column of Toner Production Example 16 in Table 1.
[0122]
(Toner Production Example 17)
・ 100 parts by mass of styrene
・ N-butyl acrylate 20 parts by mass
Polyester resin (number average molecular weight 3200) 15 parts by mass
・ Dodecanethiol 5 parts by mass
・ Carbon tetrabromide 1.5 parts by mass
The above components were mixed and dissolved, and dispersed in a flask in 140 parts by mass of ion-exchanged water to which 3.0 parts by mass of a nonionic surfactant and 3.0 parts by mass of an anionic surfactant were added. And emulsified. 10 parts by mass of ion-exchanged water in which 0.1 part by mass of ammonium persulfate was dissolved was added thereto, and after nitrogen substitution, the contents were heated to 65 ° C. while stirring the flask, and emulsion polymerization was performed for 5 hours. The resin particle dispersion was prepared.
[0123]
on the other hand,
・ Colorant (CI Pigment Yellow 180) 25 parts by mass
・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 3.5 parts by mass
・ Ion-exchanged water 120 parts by mass
The above components were mixed, dispersed using a homogenizer, and then subjected to a circulating ultrasonic disperser to prepare a colorant particle dispersion having an average particle size of 150 nm.
[0124]
on the other hand,
Ester wax (melting point 60 ° C) 12.5 parts by mass
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2.5 parts by mass
60 parts by mass of ion exchange water
The above components were mixed, and the same operation as that of the colorant particle dispersion was performed to obtain a release agent dispersion having a center particle size of 180 nm.
[0125]
Then prepared above
50 parts by mass of resin particle dispersion
Colorant dispersion 12 parts by mass
Release agent dispersion 12 parts by mass
Cationic surfactant 0.35 parts by mass
Was mixed and dispersed in a round stainless steel flask with Ultra Turrax T50 (manufactured by IKA), and then the flask was heated to 50 ° C. with stirring in an oil bath for heating. After holding at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a particle size of 6.2 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour.
[0126]
To the dispersion containing the aggregate particles, 12.5 parts by mass of the resin particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain yellow toner particles. Various physical properties of the obtained toner are shown in the column of Toner Production Example 17 in Table 1.
[0127]
(Toner Production Example 18)
In Toner Production Example 17, the colorant is C.I. I. Magenta toner particles were produced in the same manner as in Toner Production Example 17 except that the pigment red 150 was used. Various properties of the obtained toner are shown in the column of Toner Production Example 18 in Table 1.
[0128]
(Toner Production Example 19)
In Toner Production Example 17, the colorant is C.I. I. Cyan toner particles were produced in the same manner as in Toner Production Example 17 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 19 in Table 1.
[0129]
(Toner Production Example 20)
In Toner Production Example 17, black toner particles were produced in the same manner as in Toner Production Example 17 except that the colorant was changed to carbon black. Various properties of the obtained toner are shown in the column of Toner Production Example 20 in Table 1.
[0130]
(Toner Production Example 21)
In Toner Production Example 1, yellow toner particles were produced in the same manner as in Toner Production Example 1 except that the ester wax was changed to one having a melting point of 40 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 21 in Table 1.
[0131]
(Toner Production Example 22)
Magenta toner particles were produced in the same manner as in Toner Production Example 2 except that in Example 2 of toner, the ester wax was changed to one having a melting point of 40 ° C. Various physical properties of the obtained toner are shown in the column of Toner Production Example 22 in Table 1.
[0132]
(Toner Production Example 23)
Cyan toner particles were produced in the same manner as in Toner Production Example 3 except that in Example 3 of toner, the ester wax was changed to one having a melting point of 40 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 23 in Table 1.
[0133]
(Toner Production Example 24)
Black toner particles were produced in the same manner as in Toner Production Example 1 except that the ester wax was changed to one having an melting point of 40 ° C. in Toner Production Example 1. Various properties of the obtained toner are shown in the column of Toner Production Example 24 in Table 1.
[0134]
(Toner Production Example 25)
In Toner Production Example 1, yellow toner particles were produced in the same manner as in Toner Production Example 1, except that the ester wax was changed to one having a melting point of 130 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 25 in Table 1.
[0135]
(Toner Production Example 26)
Magenta toner particles were produced in the same manner as in Toner Production Example 2 except that the ester wax was changed to one having an melting point of 130 ° C. in Toner Production Example 2. Various physical properties of the obtained toner are shown in the column of Toner Production Example 26 in Table 1.
[0136]
(Toner Production Example 27)
Cyan toner particles were produced in the same manner as in Toner Production Example 3 except that in Example 3 of toner, the ester wax was changed to one having a melting point of 130 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 27 in Table 1.
[0137]
(Toner Production Example 28)
Black toner particles were produced in the same manner as in Toner Production Example 1, except that in Example 1 of toner, the ester wax was changed to one having a melting point of 130 ° C. Various properties of the obtained toner are shown in the column of Toner Production Example 28 in Table 1.
[0138]
(Toner Production Example 29)
In Toner Production Example 1, 0.1 mol / liter-Na_ThreePO_Four0.2 mol / liter-Na instead of aqueous solution_ThreePO_FourWith aqueous solution and 1.0 mol / liter CaCl₂Yellow toner particles were produced in the same manner as in Toner Production Example 1 except that the addition amount of the aqueous solution was changed to 136 parts by mass. Various physical properties of the obtained toner are shown in the column of Toner Production Example 29 in Table 1.
[0139]
(Toner Production Example 30)
In Toner Production Example 29, the colorant is C.I. I. Magenta toner particles were produced in the same manner as in Toner Production Example 29 except that the pigment red 150 was used. Various properties of the obtained toner are shown in the column of Toner Production Example 30 in Table 1.
[0140]
(Toner Production Example 31)
In Toner Production Example 29, the colorant is C.I. I. Cyan toner particles were produced in the same manner as in Toner Production Example 29 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 31 in Table 1.
[0141]
(Toner Production Example 32)
In Toner Production Example 29, black toner particles were produced in the same manner as in Toner Production Example 29 except that the colorant was changed to carbon black and the addition amount was 10 parts by mass. Various properties of the obtained toner are shown in the column of Toner Production Example 32 in Table 1.
[0142]
(Toner Production Example 33)
In Toner Production Example 1, 0.1 mol / liter-Na_ThreePO_Four0.07 mol / liter-Na instead of aqueous solution_ThreePO_FourWith aqueous solution and 1.0 mol / liter CaCl₂Toner particles were produced in the same manner as in Yellow toner production example 1 except that the amount of the aqueous solution added was changed to 50 parts by mass. Various properties of the obtained toner are shown in the column of Toner Production Example 33 in Table 1.
[0143]
(Toner Production Example 34)
In Toner Production Example 33, the colorant is C.I. I. Magenta toner particles were produced in the same manner as in Toner Production Example 33 except that the pigment red 150 was used. Various properties of the obtained toner are shown in the column of Toner Production Example 34 in Table 1.
[0144]
(Toner Production Example 35)
In Toner Production Example 33, the colorant is C.I. I. Cyan toner particles were produced in the same manner as in Toner Production Example 33 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 35 in Table 1.
[0145]
(Toner Production Example 36)
In Toner Production Example 33, black toner particles were produced in the same manner as in Toner Production Example 33 except that the colorant was changed to carbon black and the addition amount was 10 parts by mass. Various properties of the obtained toner are shown in the column of Toner Production Example 36 in Table 1.
[0146]
(Example of carrier production)
・ Phenol 7.5 parts by mass
-Formalin solution 11.25 parts by mass
(Formaldehyde about 40%, methanol about 10%, the rest is water)
・ 53 parts by mass of magnetite fine particles lipophilically treated with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane
(Average particle size 0.24 μm, specific resistance 5 × 10^FiveΩ · cm)
.Alpha.-Fe oleophilically treated with 1.0% by mass of .gamma.-glycidoxypropyltrimethoxysilane₂O_Three35 parts by mass of fine particles
(Average particle size 0.60 μm, specific resistance 2 × 10⁹Ω · cm)
Magnetite and α-Fe used here₂O_ThreeThe lipophilic treatment of 99 parts by mass of magnetite and α-Fe₂O_Three1.0 parts by mass of γ-glycidoxypropyltrimethoxysilane was added to each of 99 parts by mass, and premixed and stirred at 100 ° C. for 30 minutes in a Henschel mixer.
[0147]
The above materials and 11 parts by mass of water were mixed at 40 ° C. for 1 hour. To this slurry, 2.0 parts by mass of 28% by mass ammonia water as a basic catalyst and 11 parts by mass of water were placed in a flask, heated to 85 ° C. over 40 minutes with stirring and mixing, and reacted for 3 hours. A phenolic resin was produced and cured. Then, after cooling to 30 degreeC and adding 100 mass parts water, the supernatant liquid was removed, the deposit 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.
[0148]
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 Nippon Steel 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%.
[0149]
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 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 under a stream of dry nitrogen at 40 ° C. and 500 torr.
[0150]
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.
[0151]
[Example 1]
For each of yellow, magenta, cyan and black toner particles obtained in Toner Production Example 1, Toner Production Example 2, Toner Production Example 3 and Toner Production Example 4, Table 2 shows 100 parts by mass of toner particles. According to the indicated external additive formulation 1, in a Henschel mixer 10B (manufactured by Mitsui Miike Chemical Co., Ltd.), mixing was performed under the conditions of a rotational speed of 3000 rpm and a stirring time of 4 minutes to obtain a negatively triboelectrically charged color toner.
[0152]
The obtained toner was charged in a replenishing toner cartridge with 400 g for each color to obtain a four-color replenishing toner cartridge. When the toner was consumed and emptied, it was replaced with a new toner cartridge.
[0153]
Further, a developer was prepared by mixing 8 parts by mass of the toner with 92 parts by mass of the magnetic material-dispersed resin carrier prepared in the carrier production example, and 250 g of this developer is shown for each color in FIG. The developer was filled into a four-color process toner cartridge.
[0154]
Using the above cartridge, the full color image forming apparatus shown in FIG. 1 is used in a low temperature and low humidity environment of 15 ° C./10% RH and a high temperature and high humidity environment of 30 ° C./80% RH. 75g / m at a printing rate of 4% with respect to the paper area, with a printing speed of 23 sheets / min.²A continuous printing test of 50,000 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.
[0155]
In all examples and comparative examples, the evaluation results at the initial stage of printing based on the following evaluation methods were all good.
[0156]
<Evaluation method>
(1) Satsuki
75g / m of A3 size fully conditioned in the test environment after the 50,000-sheet continuous print test²On paper, all solid images of each color 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
[0157]
(2) Toner fusion on the photosensitive drum
After the 50,000-sheet continuous print test is completed, remove the weak deposits remaining on the drum by air blow, and then visually and microscopically observe it. It was.
A: Toner adhesion is not visually observed. When observation with a microscope of 200 times is performed at a position about 5 cm from each end of the drum center and the image forming region, toner fusion is not confirmed.
B: Toner adhesion is not visually observed. When 200 × microscope observation was performed at positions approximately 5 cm from the center of the drum and both ends of the image forming area, toner fusion of less than 15 μm was observed in a field of view of 1 cm × 1 cm at three or less observation positions. One to two is confirmed.
C: No toner fusion observation is visually observed. When 200-times microscope observation was performed at positions approximately 5 cm from the center of the drum and both ends of the image forming area, toner fusion of less than 15 μm was observed in a 1 cm × 1 cm field of view at one or more observation locations. Three or more toner particles are confirmed, and toner fusion of 15 μm or more is confirmed from one to two in a visual field of 1 cm × 1 cm at three or less observation locations.
D: Toner adhesion is visually observed. Alternatively, when 200-fold microscope observation is performed at positions approximately 5 cm from the center of the drum and both ends of the image forming area, toner fusion of less than 15 μm is 1 cm × 1 cm at one or more observation locations. Three or more are confirmed in the visual field, and three or more toner fusions of 15 μm or larger are confirmed in the visual field of 1 cm × 1 cm at one or more observation places.
[0158]
(3) Charging member contamination
75g / m of A3 size fully conditioned in the test environment after the 50,000-sheet continuous print test²On paper, an all-white image of each color was printed and visually evaluated according to the following criteria.
A: Partial print is not confirmed
B: When partial printing is confirmed and the used charging member is replaced with a new charging member, it disappears
[0159]
In all of the examples and comparative examples, partial printing was confirmed, and even when the used charging member was replaced with a new charging member, there was no example in which it was not lost.
[0160]
(4) Spotted solid image omission
75g / m of A3 size fully conditioned in the test environment after the 50,000-sheet continuous print test²On paper, all solid images of each color were printed and visually evaluated based on the following criteria.
A: A uniform solid image is printed.
B: One white spot in a circular shape is confirmed.
C: Two or more spots that are white in a circular shape are confirmed.
[0161]
(5) Streaky solid image omission
75g / m of A3 size fully conditioned in the test environment after the 50,000-sheet continuous print test²On paper, all solid images of each color 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 a solid image with a slight white spot on the streak.
C: It can be confirmed that the image is a solid image with a white portion slightly on the streak having a width of 0.3 mm or less.
D: It can be confirmed that the image is a solid image with white portions on stripes wider than 0.3 mm in width.
[0162]
(6) Striped halftone image missing
75g / m of A3 size fully conditioned in the test environment after the 50,000-sheet continuous print test²On paper, all halftone images of each color were printed and visually evaluated according to the following criteria.
A: A uniform all-halftone image is printed
B: When viewed over the light, it can be confirmed that the image is a full halftone image with a slight white spot on the streak.
C: It can be confirmed that the image is a full halftone image having a white portion slightly above the streak having a width of 0.3 mm or less.
D: It can be confirmed that the image is a full halftone image having a white portion on a stripe larger than a width of 0.3 mm.
[0163]
(7) Developer deterioration
After completion of the 50,000-sheet continuous printing test, the particle size distribution of the toner in the developer was measured with a Coulter counter, and the particle ratio of 16% or more in terms of the weight average particle size was calculated.
[0164]
[Examples 2 to 5]
Using the toners shown in Examples 2 to 5 in Table 1, each toner was examined in the same manner as in Example 1 according to the external additive formulation 1 shown in Table 2. The evaluation results are shown in Table 3.
[0165]
  [referenceExample 6]
  In Example 1, the same examination as in Example 1 was performed except that the inorganic fine particles used were changed to the external additive formulation 2 shown in Table 2. The evaluation results are shown in Table 4.
[0166]
  [referenceExample 7]
  In Example 1, the same examination as in Example 1 was performed except that the inorganic fine particles used were changed to the external additive formulation 3 shown in Table 2. The evaluation results are shown in Table 4.
[0167]
  [referenceExample 8]
  In Example 1, the full-color image forming apparatus shown in FIG. 1 was remodeled into a contact nonmagnetic one-component development system, and a process cartridge charged with 270 g of developer was produced, and the bias at the time of development was only DC, and the charging member As a charging roller, when a blank before and after development, a bias of DC and AC components is applied to control the potential so that the remaining toner on the photoreceptor can be collected, and the printing speed is 15 sheets / min. 75g / m at a print ratio of 4% to the paper area²A continuous test of 10,000 sheets of A4 plain paper was conducted. At that time, various evaluations were performed using the evaluation items shown in Example 1. The evaluation results are shown in Table 4.
[0168]
[Example 9]
In Example 1, the same examination as in Example 1 was performed except that the primary transfer roller was changed to a blade-like contact transfer member. The evaluation results are shown in Table 4.
[0169]
[Example 10]
In Example 1, the magnetic carrier used as the developer was changed to an acrylic-coated ferrite carrier, and the developer was prepared by mixing 93 parts by mass of the carrier with 7 parts by mass of the toner. Was examined. The evaluation results are shown in Table 4.
[0170]
[Comparative Examples 1-3]
Using the toners shown in Comparative Examples 1 to 3 of Table 1, each toner was examined in the same manner as in Example 1 according to the external additive formulation 1 shown in Table 2. As a result, problems as shown in Table 5 occurred.
[0171]
[Comparative Example 4]
Using the toner shown in Comparative Example 4 in Table 1, each toner was examined in the same manner as in Example 1 according to the external additive formulation 1 shown in Table 2. As a result, evaluation results as shown in Table 5 were obtained, but 75 g / m at a print ratio of 4%.²During the continuous printing test for 50,000 sheets of A4 plain paper, images with noticeable scattering were obtained for all the colors from about 1000 printed sheets.
[0172]
[Comparative Example 5]
In Example 1, examination was performed in the same manner as in Example 1 except that the inorganic fine particles used were changed to the external additive formulation 4 shown in Table 2. Since the evaluation was performed using a toner containing no oil-treated silica, problems as shown in Table 5 occurred.
[0173]
[Table 1]

[0174]
[Table 2]

[0175]
[Table 3]

[0176]
[Table 4]

[Table 5]

[0177]
【The invention's effect】
Toner and full-color image forming method satisfying high speed, high image quality, high durability, low environmental load, compatibility with various media and high environmental stability.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an image forming apparatus to which the present invention is applied.
FIG. 2 is an explanatory diagram of a process cartridge.
FIG. 3 is an explanatory diagram of a process cartridge of a contact one-component developing system.

Claims (12)

An image forming method in which an electrostatic charge image carrier for carrying at least an electrostatic charge image for each color toner and a developing device having means for developing the electrostatic charge image are assigned, and the developing devices are arranged in a tandem type. Yes, the electrostatic image carrier is charged, an electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with a non-magnetic toner contained in a two-component developer included in the developing means. An image in which a toner image is formed, a full-color image is formed by transferring the toner image to an intermediate transfer member, the full-color image is collectively transferred to a transfer material, and the full-color image on the transfer material is fixed by a thermal fixing unit. A forming method comprising:
The electrostatic charge image bearing member is charged by a contact roller and developed by a two-component developer comprising a non-magnetic toner and a magnetic carrier, and the developing means also serves to collect the transfer residual toner and is a member that contacts the intermediate transfer member The toner image is transferred to the intermediate transfer member, the full-color image is transferred to the transfer material by a member in contact with the transfer material, and the fixing unit is a fixing unit that does not include an oil application mechanism. In the two-component developer used,
The toner has at least a low softening point compound having a melting point of 50 ° C. to 120 ° C., and at least two types of silica fine particles having different particle diameters treated with a silane coupling agent and oil adhere to the toner surface. A two-component developer, wherein the toner has a weight average particle diameter (D4) of 3 μm to 11 μm.   2. The two-component developer according to claim 1, wherein the two-component developer is used in an image forming method in which a toner image of the electrostatic charge image bearing member is transferred to the intermediate transfer member by a contacting roller.   3. The two-component developer according to claim 1, wherein the two-component developer is used in an image forming method in which a toner image of the intermediate transfer member is transferred to a transfer material by a contact roller.   The two-component developer according to claim 1, wherein the magnetic carrier is a magnetic material-dispersed resin carrier. The average circularity measured by a flow type particle image measuring device of the toner is 0.950 to 1.000, more of claims 1 to 4 circularity standard deviation is equal to or less than 0.040 A two-component developer according to claim 1. The two-component developer according to any one of claims 1 to 5 , wherein the toner contains at least a condensation compound, and the number average molecular weight of the condensation compound is 2000 to 10,000. . An image forming method in which an electrostatic charge image carrier for carrying at least an electrostatic charge image for each color toner and a developing device having means for developing the electrostatic charge image are assigned, and the developing devices are arranged in a tandem type. Yes, the electrostatic image carrier is charged, an electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with a non-magnetic toner contained in a two-component developer included in the developing means. An image in which a toner image is formed, a full-color image is formed by transferring the toner image to an intermediate transfer member, the full-color image is collectively transferred to a transfer material, and the full-color image on the transfer material is fixed by a thermal fixing unit. A forming method comprising:
The electrostatic charge image carrier is charged by a contact roller and developed by a two-component developer comprising a non-magnetic toner and a magnetic carrier, and the developing means also serves to collect the transfer residual toner and is a member that contacts the intermediate transfer member In the image forming method, the toner image is transferred to the intermediate transfer member by the transfer, the full-color image is transferred to the transfer material by a member in contact with the transfer material, and the fixing unit is a fixing device that does not include an oil application mechanism. ,
The toner has at least a low softening point compound having a melting point of 50 ° C. to 120 ° C., and at least two types of silica fine particles having different particle diameters treated with a silane coupling agent and oil adhere to the toner surface. An image forming method, wherein the toner has a weight average particle diameter (D4) of 3 μm to 11 μm. The image forming method according to claim 7 , wherein the toner image of the electrostatic charge image bearing member is transferred to the intermediate transfer member by a contacting roller. The image forming method according to claim 7 or 8 toner image of the intermediate transfer member, characterized in that it is transferred to the transfer material by contacting the roller. Magnetic carrier, the image forming method according to any one of claims 7 to 9, characterized in that a magnetic material-dispersed resin carrier. The average circularity measured by a flow type particle image measuring device of the toner is 0.950 to 1.000, more of claims 7 to 10 circularity standard deviation is equal to or less than 0.040 An image forming method according to claim 1. The toner contains at least a condensation compound, and an image forming method according to any one of claims 7 to 11 fused system compound has a number average molecular weight is characterized in that it is a 2,000 to 10,000.

Images